JP7646571B2 - Hydrogen peroxide based explosive with improved sleep time - Google Patents

Description

The present invention relates to an improved hydrogen peroxide-based explosive. The invention has been developed primarily for use as a hydrogen peroxide/fuel-based explosive composition for use in mining applications and will be described below with respect to this application. However, it will be appreciated that the invention is not limited to use in this particular field.

The following discussion of the prior art is provided to place the invention in a suitable technical context so that its advantages may be more fully understood. However, it should be recognized that any discussion of prior art throughout this specification should not be construed as an express or implied admission that such prior art is widely known or forms part of the common general knowledge in the field.

Nearly all commercial mining explosives used in the world today are based on ammonium nitrate (AN) or a combination of AN with smaller amounts of other alkali and/or alkaline earth nitrates, such as sodium nitrate (SN) or calcium nitrate (CN). AN, a strong oxidizer, has been used as a commercial explosive base for at least the last 50-60 years. Most explosives of this type rely on the energetic reaction of nitrogen compounds incorporated within the explosive to provide the necessary explosive power.

At first, mining companies used AN itself as the explosive. But they soon learned that the addition of diesel fuel (ammonium nitrate-fuel oil, now commonly referred to as "ANFO") increased the energy output without significantly increasing the cost. However, the water resistance of ANFO is quite poor, limiting its use in wet blast holes. To remedy this problem, slurries and hydrogels were developed. Slurry explosives typically contain AN dissolved/dispersed in water, other salts (e.g., calcium nitrate, sodium nitrate, amine nitrates, perchlorates, etc.), and other additives such as guar gum (as a thickener) and water-soluble or water-insoluble fuels (glycerin, MMAN, diesel fuel, etc.). They can also be blended with ANFO depending on the characteristics of the land to be blasted. Slurry explosives also typically contain a solid sensitizer (aluminum and explosives such as TNT, RDX, etc.) that allows the slurry to detonate and misfires are minimized. Hydrogels have a similar composition to slurries, but a cross-linking agent can be added to increase the product's water resistance.

One of the drawbacks of hydrous gels and slurries is that there is a limit to the amount of AN that can be incorporated into the solution. This drawback was overcome with the development of water-in-oil emulsions. These emulsions can contain high concentrations of AN because the emulsions are made at high temperatures (see U.S. Patent No. 3,447,978). Water-in-oil emulsions are made from a hot aqueous phase (consisting of AN, other nitrates, perchlorates, etc.) dispersed in an organic fuel. The aqueous-organic mixture is stabilized by the use of emulsifiers. The emulsions can also be blended with ANFO in different ratios to suit the land to be blasted.

However, despite the development of AN emulsions, AN slurries and hydrogels, there is still a need to develop improved explosives that are more cost-effective compared to existing explosive compositions and can be produced in large quantities to meet the high demands from industry. It would be advantageous to provide an alternative to the use of AN by using less AN in the formulation and substituting other types of nitrates. In addition, such alternatives should preferably be safer, have a relatively low carbon footprint, be fabricated close to the site of use, minimizing transportation on public roads, be fabricated in stages of need, minimizing the need for stockpiling, while increasing safety, allowing the use of existing distribution facilities, and/or producing little (or no) toxic nitrogen oxide after-gases (NO _x ) upon detonation, etc. It would also be ideal if such alternatives were free of burdensome regulatory requirements, thereby reducing administrative costs. It would also be preferable for the explosive composition to be crosslinkable in situ and thickened down the blast hole.

Despite the advances in the type of compositions that can be made from ammonium nitrate, one of the disadvantages is that during detonation, NO _x after gases can be generated due to the presence of nitrogen compounds (from nitrates) in the explosive composition. These NO _x after gases are toxic and can affect the health of mining site personnel. Thus, the release of NO _x after gases after blasting is a safety issue and in countries such as Australia, there are now stringent regulatory controls in place to control such releases. See, for example, Queensland Handbook: Control of Nitrogen Oxides in Open Core Blasting, published by the regulatory authority in Queensland, Australia, 2011. Similarly, explosive manufacturers in Australia have also issued codes of practice to control NO _x after gases after blasting. (AEISG Code of Practice, Prevention and Management of Blast Generated NO _x Gases in Surface Blasting, 2011). Thus, there is a need to find explosive compositions that substantially reduce the generation of NO _x .

One material that is also an oxidizer and may meet at least some of these needs is _hydrogen peroxide ( _H2O2 ). _H2O2 /fuel-based explosives for mining operations generally consist of _{a combination} of _H2O2 with about 5 to about 15 percent of its mass of a liquid carbon-based fuel, such as glycerin, fuel oil, etc. However, in some cases, _{H2O2 -} based explosives have proven less than ideal when sleep times greater than 24 hours are required, as changes in density over time have been observed that can affect parameters such as velocity of detonation (VOD).

U.S. Patent No. 3,447,978 U.S. Patent No. 3,400,026 U.S. Patent No. 3,582,411 U.S. Patent No. 3,678,140 U.S. Patent No. 4,326,900 U.S. Patent No. 4,820,361 U.S. Patent No. 4,547,234 U.S. Patent No. 5,470,407 U.S. Patent No. 5,271,779 U.S. Patent No. 5,409,556

The present invention aims to overcome or ameliorate one or more of the disadvantages of the prior art, or at least to provide a useful alternative.

It is an object of preferred embodiments of the present invention to provide _H2O2 / _fuel -based explosives with improved sleep times. The preferred explosive compositions of the present invention substantially maintain sensitivity, density and VOD over extended sleep times, which may range from 24 to 48 hours, or even longer. The improved explosive compositions of the present invention, due to their extended sleep times, can be safely used in mines and, in some embodiments, allow for blasts to be performed that are not possible with prior art _{H2O2 -} based explosive compositions that do not have the extended sleep times provided by the compositions of the present invention. In particular, because the explosive compositions of the present invention described herein substantially maintain the VOD in the blast hole for extended periods of time, much larger blasts can be performed with the compositions of the present invention.

A preferred objective of embodiments of the present invention is to provide an explosive composition that meets one or more of the following objectives: it is conveniently prepared, it has in situ improved density stability over time, it can use large amounts of sustainable fuels (reducing the carbon footprint of the explosive), in some preferred embodiments it can use large amounts of nitrates other than AN (reducing the dependency on AN), and it can have an extended sleep time, allowing for a much larger blast.

A further preferred object of the present invention is to substantially maintain the density of the explosive composition when loaded into a blast hole, thereby substantially maintaining sleep time for days and potentially even weeks.

The present invention relates to explosives for use in commerce, construction, civil engineering, agriculture, mining and similar fields. However, it will be appreciated that the present invention may be utilized in other related fields.

Surprisingly, it has been discovered that _{H2O2 -} based explosive compositions, when treated or modified with a density stabilizer (i.e., phosphonate), exhibit improved sleep times over prior art _{H2O2 -} based explosive compositions. Even more surprisingly, it has been found that only a relatively small amount of phosphonate improves density stability and sleep times. Without wishing to be bound by any theory, the inventors believe that the density stabilizer used in the present invention acts to prevent the incorporated sensitizer gas from spontaneously forming additional bubbles, whereas without the density stabilizer, existing sensitizer bubbles tend to increase in volume and number over time.

In the practice of the present invention, the phosphonate, usually in liquid form, is added to _{the H2O2} prior to the addition of the fuel. A thickener may be added to the combined oxidizer/fuel mixture.

Typically, one or more density stabilizers are incorporated in an amount of up to about 15% by weight of the explosive composition, such as from about 0.01% to about 10% by weight, such as from about 1% to about 5% by weight, such as from about 1% to about 3% by weight. The density stabilized _{H2O2 -} based explosive can then be handled, loaded, and ignited in the same manner as other explosives.

According to a first aspect, the present invention provides a method for producing ... liquid crystal display comprising the steps of:
a. _{H2O2 ;}
b. Fuel; and
c. Providing an explosive composition comprising one or more density stabilizers.

According to a second aspect, the present invention provides a method for preparing an explosive composition according to the first aspect, comprising combining _H2O2 , _a fuel and one or more density stabilizers, and optionally one or more other oxidizers and/or sensitizers.

According to a third aspect, the present invention provides the use of an explosive composition according to the first aspect for digging and moving earth, for example in mining operations.

According to a fourth aspect, the present invention provides the use _of one or more density stabilizers to improve the sleep time of an explosive composition comprising _H2O2 and a fuel in reactive or metal-bearing grounds.

In a related aspect, the invention comprises a method of treating an explosive composition to improve its long-term stability (sleep time), comprising combining a density stabilizer with _the explosive composition comprising _H2O2 and a fuel to stabilize the density of the explosive composition. In a related aspect, the invention comprises the use of a density stabilizer to improve the long-term stability of the explosive composition. The density stabilizer is used in a density stabilizing concentration.

The present invention relates to an explosive which substantially avoids the release of undesirable NO _x post-gases upon detonation into the atmosphere surrounding the blasting site. A preferred object of the present invention is to reduce, and preferably eliminate, nitrogen-containing materials from the explosive composition. It will be appreciated that since little or no nitrogen is present in the explosive, virtually no NO _x is released into the atmosphere or a substantially reduced amount is released. The present invention relates to an explosive used in commerce, construction, agriculture, mining and similar fields. However, it will be appreciated that the present invention can be utilized in other related fields.

The density is maintained by including a density stabilizer that maintains the density of the explosive composition within +/- 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 14, 16, 18, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 35, 40, or 50% of its initial density and/or maintains the density of the explosive composition within 5, 10, 15, 20, 30, or 60, 90, or 120 minutes after loading into the blast hole. The density is preferably maintained (or stabilized) for a period of up to 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, or 14 days. The density stabilizer preferably maintains the VOD within +/- 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 14, 16, 18, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 35, 40, or 50% of the initial VOD, or maintains the VOD of the explosive composition for 5, 10, 15, 20, 30, 60, 90, or 120 minutes after loading into the blast hole. The VOD is preferably maintained for a period of up to 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, or 14 days.

The compositions of the present invention have a predictable and controllable change in density and VOD over time. For example, at a given concentration of density stabilizer, the density drops from about 5% per day to about 10% per day, causing a corresponding drop in VOD of about 5% to 10% per day. This allows the drilling and blasting engineer to obtain a desired VOD after a sleep time, since the amount of density stabilizer can be selected to control the change in density over a sleep time. It will be appreciated that in some prior art compositions, the density drops from about 10% per day to about 30% per day, causing a corresponding drop in VOD of about 10% to 30% per day.

Preferably, the composition further comprises other additives, such as fuel, water, thickeners, emulsifiers, mechanical sensitizers, chemically derived sensitizers, injection gas, etc., as discussed further below. In one preferred embodiment, the composition does not contain any components that lead to the production of _NOx in the tail gas after detonation. However, in other embodiments, components are added that result in minimal _NOx in the tail gas after detonation.

Although the preferred explosive oxidizer of the present invention is hydrogen peroxide, it will be understood that other oxidizer salts or peroxide derivatives may be used in the present invention as partial replacements for _{H2O2 .} Non-limiting examples include nitrates, perchlorates, sodium/potassium peroxide, and the like.

DEFINITIONS In describing and claiming the present invention, the following terms will be used in accordance with the definitions set out below. It is also to be understood that the terms used herein are for the purpose of describing particular embodiments of the present invention only and are not intended to be limiting. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention pertains.

Unless the context clearly requires otherwise, throughout this description and claims, the words "comprise," "comprising," and the like, are to be construed in their inclusive sense as opposed to their exclusive or exhaustive sense; i.e., "including but not limited to."

Other than in the working examples, or unless otherwise specified, all numbers expressing amounts of ingredients or reaction conditions used herein should be understood to be modified in all instances by the term "about." The examples are not intended to limit the scope of the invention. In the content that follows or unless otherwise indicated, "%" means "% by weight," "ratio" means "ratio by weight," and "parts" means "parts by weight."

Unless the context clearly dictates otherwise, all references to components present in a certain weight percent are to the total explosive composition. For example, an explosive composition containing 2-25 weight percent hydrogen peroxide refers to an explosive composition containing 2-25 grams of hydrogen peroxide per 100 grams of explosive composition.

The term _H2O2 is an abbreviation for hydrogen _peroxide .

The term AN means ammonium nitrate.

CN stands for calcium nitrate tetrahydrate.

CAN stands for calcium ammonium nitrate.

SN is the abbreviation for sodium nitrate.

ANFO is the abbreviation for ammonium nitrate fuel oil.

Amine nitrate is an abbreviation for the nitrate salts of monomethylamine, ethylamine, or propylamine.

Sensitizer refers to an additive that introduces voids into the composition. Sensitizers enable and increase the sensitivity of energetic materials to detonation. Sensitizers can be chemically generated voids (gas bubbles) or can surround or entrap gas (examples include ceramic/glass microballoons, EPS and polyurethane foams).

GMB is an abbreviation for glass microballoons.

EPS is an abbreviation for expanded polystyrene.

TNT stands for trinitrotoluene.

HMX stands for octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine.

RDX stands for 1,3,5-trinitroperhydro-1,3,5-triazine.

VOD refers to the speed of the detonation in m/sec.

OB stands for oxygen balance.

The term g/ ^cm3 has the same meaning as g/ml.

Phosphonates are organic compounds with C-P bonds, such as C-PO(OH) ₂ or C-PO(OR) ₂ groups. As used herein, "phosphonate" also includes phosphonate salts that contain a phosphonate anion with a counter cation (e.g., sodium salt). "Phosphonate" includes monophosphonates, as well as bisphosphonates and higher phosphonates. The R group of the phosphonate is not limited to alkyl, and may include, for example, a heteroatom (e.g., N).

DTPMPA.Na.x means _{diethylenetriaminepentamethylenephosphonic} acid _sodium salt ( _{C9H28 -xN3O15P5Nax ,} CAS number _22042-96-2 ).

The term phosphate refers to a chemical derivative of phosphoric acid. ^The phosphate ion ( _PO43- ) is the conjugate base of phosphoric acid and can form many different salts. Organophosphonates have the general structure O=P(OR) ₃ , where the R groups can be the same or different. R includes alkyl and aryl. Phosphates contain COP bonds and not the CP bonds present in phosphonates.

The term "stannate" refers to a compound containing tin(II), (IV) or (VI) and oxygen.

Sleep time is understood to be the time between when the explosives are loaded into the blast hole and when they are detonated. The period is typically several days.

The terms "preferred," "preferably," and "suitably" refer to embodiments of the invention that may provide certain advantages, under certain circumstances. However, other embodiments may be preferred, under the same or other circumstances. Furthermore, the description of one or more preferred embodiments does not imply that other embodiments are not useful, and is not intended to exclude other embodiments from the scope of the invention.

The terms 'a', 'an' and 'the' mean 'one or more' unless expressly indicated otherwise. The terms 'an embodiment', 'embodiment', 'embodiments', 'the embodiment', 'the illustration', 'an embodiment', 'some illustration', 'an example embodiment', 'at least one illustration', 'one or more illustration' and 'one embodiment' mean 'one or more (but not necessarily all) embodiments of the present invention' unless expressly indicated otherwise.

The terms "underground" or "subsurface" refer to the area below exposed ground surface and to areas below ground surface that are covered by water, including fresh and salt water.

As used throughout this specification, the term "optionally substituted" refers to a group that may or may not be further substituted or fused (thereby forming a fused polycyclic system) with one or more non-hydrogen substituents. In certain embodiments, the substituents are halogen, =O, =S, -CN, -NO2, _-CF3 , _-OCF3 , alkyl, _alkenyl , alkynyl, haloalkyl, haloalkenyl, haloalkynyl, heteroalkyl, cycloalkyl, cycloalkenyl, heterocycloalkyl, heterocycloalkenyl, aryl, heteroaryl, cycloalkylalkyl, heterocycloalkylalkyl, heteroarylalkyl, arylalkyl, cycloalkylalkenyl, heterocycloalkylalkenyl, arylalkenyl, heteroarylalkenyl, cycloalkylheteroalkyl, heterocycloalkylheteroalkyl, arylheteroalkyl, heteroarylheteroalkyl, hydroxy, hydroxyalkyl, alkyloxy, alkyloxyalkyl, alkyloxycycloalkyl, alkyloxyhetero ... alkyl, alkyloxyaryl, alkyloxyheteroaryl, alkyloxycarbonyl, alkylaminocarbonyl, alkenyloxy, alkynyloxy, cycloalkyloxy, cycloalkenyloxy, heterocycloalkyloxy, heterocycloalkenyloxy, aryloxy, phenoxy, benzyloxy, heteroaryloxy, arylalkyloxy, amino, alkylamino, acylamino, aminoalkyl, arylamino, sulfonylamino, sulfinylamino, sulfonyl, alkylsulfonyl, arylsulfonyl, aminosulfonyl, sulfinyl, alkylsulfinyl, arylsulfinyl, aminosulfinylaminoalkyl, -C(=O)OH, -C(=O)R one ^or more groups independently selected ^from the group consisting of ^{: -C} (=O) ^ORe , C(= ^O ) ^NReRf , C(=NOH) ^Re , ^{C (} =NRe) ^NRfRg , ^NRERf , ^NREC (=O) ^Rf , ^NREC (= ^O ) ^ORf , ^{NREC (} =O ₎ ^NRfRg , ^{NREC( =} NRf) ^{NRgRh ,} NRESO2Rf, ^-SRe , ^SO2NReRf , ^-ORe , OC ⁽ ₌ O) ^NReRf , OC(=O) ^Re and acyl ^;
wherein R ^e , R ^f , R ^g and R ^h are each independently selected from the group consisting of H, C ₁ -C ₁₂ alkyl, C ₁ -C ₁₂ haloalkyl, C ₂ -C ₁₂ alkenyl, C ₂ -C ₁₂ alkynyl, C ₁ -C ₁₀ heteroalkyl, C ₃ -C ₁₂ cycloalkyl, C ₃ -C ₁₂ cycloalkenyl, C ₁ -C ₁₂ heterocycloalkyl, C ₁ -C ₁₂ heterocycloalkenyl, C ₆ -C ₁₈ aryl, C ₁ -C ₁₈ heteroaryl and acyl, or any two or more of R ^a , R ^b , R ^c and R ^d together with the atoms to which they are attached form a heterocyclic ring having from 3 to 12 ring atoms.

In some embodiments, each optional substituent is independently selected from the group consisting _of halogen, =O, =S, -CN, -NO2, _-CF3 , _-OCF3 , alkyl, alkenyl, alkynyl, haloalkyl, haloalkenyl, haloalkynyl, heteroalkyl, cycloalkyl, cycloalkenyl, heterocycloalkyl, heterocycloalkenyl, aryl, heteroaryl, hydroxy, hydroxyalkyl, alkyloxy, alkyloxyalkyl, alkyloxyaryl, alkyloxyheteroaryl, alkenyloxy, alkynyloxy, cycloalkyloxy, cycloalkenyloxy, heterocycloalkyloxy, heterocycloalkenyloxy, aryloxy, heteroaryloxy, arylalkyl, heteroarylalkyl, arylalkyloxy, amino, alkylamino, acylamino, aminoalkyl, arylamino, sulfonyl, alkylsulfonyl, arylsulfonyl, aminosulfonyl, aminoalkyl, -COOH, -SH, and acyl.

Examples of particularly suitable optional substituents include F, Cl, Br, I, _CH3 , _CH2CH3 , OH, _OCH3 , _CF3 , _OCF3 , _NO2 , _NH2 and _CN .

In the definitions of some of the substituents below, it is stated that "the group may be a terminal group or a bridging group." This is intended to mean that use of the term is intended to encompass the situation where the group is a linker between two other parts of the molecule and it is the terminal moiety. Using the term alkyl as an example, some publications use the term "alkylene" as the bridging group, while in other publications there is a distinction between the terms "alkyl" (terminal group) and "alkylene" (bridging group). In this application, there is no such distinction and most groups may be either a bridging group or a terminal group.

"Acyl" means the group R-C(=O)-, where R may be an alkyl, cycloalkyl, heterocycloalkyl, aryl, or heteroaryl group as defined herein. Examples of acyl include acetyl and benzoyl. The group may be a terminal group or a bridging group. When the group is a terminal group, it is attached to the remainder of the molecule through the carbonyl carbon.

"Acylamino" means the group R-C(=O)-NH-, where R can be an alkyl, cycloalkyl, heterocycloalkyl, aryl or heteroaryl group as defined herein. The group can be a terminal group or a bridging group. When the group is a terminal group, it is attached to the remainder of the molecule through the nitrogen atom.

"Alkenyl" as a group or part of a group refers to an aliphatic hydrocarbon group containing at least one carbon-carbon double bond, preferably having 2 to 12 carbon atoms in the linear chain, more preferably 2 to 10 carbon atoms, and most preferably 2 to 6 carbon atoms, and may be linear or branched. The group may contain multiple double bonds in the linear chain, the orientation for each being independently E or Z. The alkenyl group is preferably a 1-alkenyl group. Exemplary alkenyl groups include, but are not limited to, ethenyl, propenyl, butenyl, pentenyl, hexenyl, heptenyl, octenyl, and nonenyl. The group may be a terminal group or a bridging group.

"Alkenyloxy" refers to the group alkenyl-O-, where alkenyl is as defined herein. Preferred alkenyloxy groups are _C1 - _C6 alkenyloxy groups. The group may be a terminal group or a bridging group. When the group is a terminal group, it is attached to the remainder of the molecule via an oxygen atom.

"Alkyl" as a group or part of a group, unless otherwise stated, refers to a linear or branched aliphatic hydrocarbon group, preferably _C1 to _C12 alkyl, more preferably _C1 to _C10 alkyl, most preferably _C1 to _C6 . Examples of suitable linear and branched _C1 to _C6 alkyl substituents include methyl, ethyl, n-propyl, 2-propyl, n-butyl, sec-butyl, t-butyl, hexyl, etc. The group may be a terminal group or a bridging group.

"Alkylamino" includes both monoalkylamino and dialkylamino unless expressly stated. "Monoalkylamino" means an alkylNH- group, where alkyl is as defined herein. "Dialkylamino" means an (alkyl) _2N- group, where each alkyl may be the same or different, and each is as defined herein for alkyl. The alkyl group is preferably a _C1 - _C6 alkyl group. The group may be a terminal group or a bridging group. When the group is a terminal group, it is attached to the remainder of the molecule via the nitrogen atom.

"Alkylaminocarbonyl" refers to a group of formula (alkyl) _x (H) _yNC (=O)-, where alkyl is as defined herein, x is 1 or 2, and the sum of X+Y=2. The group may be a terminal group or a bridging group. When the group is a terminal group, it is attached to the remainder of the molecule through the carbonyl carbon.

"Alkyloxy" refers to the group alkyl-O-, where alkyl is as defined herein. Preferably, the alkyloxy is a _C1 - _C6 alkyloxy. Examples include, but are not limited to, methoxy and ethoxy. The group may be a terminal or bridging group.

"Alkyloxyalkyl" refers to an alkyloxy-alkyl group in which the alkyloxy and alkyl moieties are as defined herein. The group may be a terminal group or a bridging group. If the group is a terminal group, it is attached to the remainder of the molecule via the alkyl group.

"Alkyloxyaryl" refers to an alkyloxyaryl- group in which the alkyloxy and aryl moieties are as defined herein. The group may be a terminal group or a bridging group. When the group is a terminal group, it is attached to the remainder of the molecule via the aryl group.

"Alkyloxycarbonyl" refers to the alkyl-OC(=O)- group, where alkyl is as defined herein. The alkyl group is preferably a _C1 - _C6 alkyl group. Examples include, but are not limited to, methoxycarbonyl and ethoxycarbonyl. The group may be a terminal group or a bridging group. When the group is a terminal group, it is attached to the remainder of the molecule through the carbonyl carbon.

"Alkyloxycycloalkyl" refers to an alkyloxy-cycloalkyl group, where the alkyloxy and cycloalkyl moieties are as defined herein. The group may be a terminal group or a bridging group. If the group is a terminal group, it is attached to the remainder of the molecule via the cycloalkyl group.

"Alkyloxyheteroaryl" refers to an alkyloxy-heteroaryl- group in which the alkyloxy and heteroaryl moieties are as defined herein. The group may be a terminal group or a bridging group. When the group is a terminal group, it is attached to the remainder of the molecule via the heteroaryl group.

"Alkyloxyheterocycloalkyl" refers to an alkyloxy-heterocycloalkyl group, where the alkyloxy and heterocycloalkyl moieties are as defined herein. The group may be a terminal group or a bridging group. If the group is a terminal group, it is attached to the remainder of the molecule via the heterocycloalkyl group.

"Alkylsulfinyl" means an alkyl-S-(=O)- group, where alkyl is as defined herein. The alkyl group is preferably a _C1 - _C6 alkyl group. Exemplary alkylsulfinyl groups include, but are not limited to, methylsulfinyl and ethylsulfinyl. The group may be a terminal group or a bridging group. When the group is a terminal group, it is attached to the remainder of the molecule through a sulfur atom.

"Alkylsulfonyl" refers to the alkyl-S(=O) _2- group, where alkyl is as defined above. The alkyl group is preferably a _C1 - _C6 alkyl group. Examples include, but are not limited to, methylsulfonyl and ethylsulfonyl. The group may be a terminal group or a bridging group. When the group is a terminal group, it is attached to the remainder of the molecule via a sulfur atom.

"Alkynyl" as a group or part of a group means an aliphatic hydrocarbon group containing a carbon-carbon triple bond, which may be linear or branched, preferably having 2 to 12 carbon atoms in the linear chain, more preferably 2 to 10 carbon atoms, more preferably 2 to 6 carbon atoms. Exemplary structures include, but are not limited to, ethynyl and propynyl. The group may be a terminal group or a bridging group.

"Alkynyloxy" refers to an alkynyl-O- group, where alkynyl is as defined herein. Preferred alkynyloxy groups are _C1 - _C6 alkynyloxy groups. The group may be a terminal group or a bridging group. When the group is a terminal group, it is attached to the remainder of the molecule via an oxygen atom.

"Aminoalkyl" means _NH2 -alkyl group, where alkyl is as defined herein. The group may be a terminal group or a bridging group. If the group is a terminal group, it is attached to the remainder of the molecule via the alkyl group.

"Aminosulfonyl" refers to the group NH2 _- S(=O) _2- . The group may be a terminal group or a bridging group. If the group is a terminal group, it is attached to the remainder of the molecule via the sulfur atom.

"Aryl" as a group or part of a group refers to (i) an optionally substituted monocyclic, or fused polycyclic, aromatic carbocyclic ring (a ring structure having all ring atoms which are carbon), preferably having 5-12 atoms per ring. Examples of aryl groups include phenyl, naphthyl, and the like; (ii) an optionally substituted partially saturated bicyclic aromatic carbocyclic moiety (wherein a phenyl and a _C5-7 cycloalkyl or _C5-7 cycloalkenyl group are fused together to form a ring structure such as tetrahydronaphthyl, indenyl, or indanyl). The group may be a terminal or bridging group. Typically, the aryl group is a _C6 - _C18 aryl group.

"Arylalkenyl" means an arylalkenyl group where aryl and alkenyl are as defined herein. Exemplary arylalkenyl groups include phenylallyl. The group may be a terminal group or a bridging group. When the group is a terminal group, it is attached to the remainder of the molecule through the alkenyl group.

"Arylalkyl" means an arylalkyl group, where the aryl and alkyl moieties are as defined herein. Preferred arylalkyl groups contain a _C1-5 alkyl moiety. Exemplary arylalkyl groups include benzyl, phenethyl, 1-naphthalenemethyl, and 2-naphthalenemethyl. The group may be a terminal group or a bridging group. When the group is a terminal group, it is attached to the remainder of the molecule via the alkyl group.

"Arylalkyloxy" refers to the group arylalkyl-O-, where alkyl and aryl are as defined herein. The group may be a terminal group or a bridging group. When the group is a terminal group, it is attached to the remainder of the molecule through an oxygen atom.

"Arylamino" includes both monoarylamino and diarylamino unless otherwise specified. Monoarylamino means a group of formula arylNH-, where aryl is as defined herein. Diarylamino means a group of formula (aryl) _2N- , where each aryl may be the same or different, and each is as defined herein for aryl. The group may be a terminal group or a bridging group. When the group is a terminal group, it is attached to the remainder of the molecule via a nitrogen atom.

"Arylheteroalkyl" means an arylheteroalkyl group, where the aryl and heteroalkyl moieties are as defined herein. The group may be a terminal group or a bridging group. When the group is a terminal group, it is attached to the remainder of the molecule via the heteroalkyl group.

"Aryloxy" refers to the group aryl-O-, where aryl is as defined herein. Preferably, the aryloxy is a _C6 - _C18 aryloxy, more preferably a _C6 - _C10 aryloxy. The group may be a terminal group or a bridging group. When the group is a terminal group, it is attached to the remainder of the molecule via an oxygen atom.

"Arylsulfonyl" means an aryl-S(=O) _2- group, where aryl is as defined herein. The group may be a terminal group or a bridging group. When the group is a terminal group, it is attached to the remainder of the molecule through the sulfur atom.

A "bond" is a connection between atoms in a compound or molecule. A bond may be a single bond, a double bond, or a triple bond.

"Cycloalkenyl" means a non-aromatic monocyclic or polycyclic ring system containing at least one carbon-carbon double bond and preferably having from 5 to 10 carbon atoms per ring. Exemplary monocyclic cycloalkenyl rings include cyclopentenyl, cyclohexenyl, or cycloheptenyl. Cycloalkenyl groups may be substituted by one or more substituents. Cycloalkenyl groups are typically _C3 - _C12 alkenyl groups. The group may be a terminal or bridging group.

"Cycloalkyl" refers to a saturated monocyclic or fused or spiropolycyclic, carbocyclic ring, preferably containing from 3 to 9 carbons per ring, unless otherwise specified, e.g., cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, and the like. It includes monocyclic systems such as cyclopropyl and cyclohexyl, bicyclic systems such as decalin, and polycyclic systems such as adamantane. Cycloalkyl groups are typically _C3 to _C12 alkyl groups. The group may be a terminal or bridging group.

"Cycloalkylalkyl" means a cycloalkyl-alkyl group in which the cycloalkyl and alkyl moieties are as defined herein. Exemplary monocycloalkylalkyl groups include cyclopropylmethyl, cyclopentylmethyl, cyclohexylmethyl, and cycloheptylmethyl. The group may be a terminal group or a bridging group. When the group is a terminal group, it is attached to the remainder of the molecule via the alkyl group.

"Cycloalkylalkenyl" means a cycloalkyl-alkenyl group in which the cycloalkyl and alkenyl moieties are as defined herein. The group may be a terminal group or a bridging group. If the group is a terminal group, it is attached to the remainder of the molecule via the alkenyl group.

"Cycloalkylheteroalkyl" means a cycloalkyl-heteroalkyl group, where the cycloalkyl and heteroalkyl moieties are as defined herein. The group may be a terminal group or a bridging group. If the group is a terminal group, it is attached to the remainder of the molecule via the heteroalkyl group.

"Cycloalkyloxy" refers to a cycloalkyl-O- group, where cycloalkyl is as defined herein. Preferably, the cycloalkyloxy is a _C1 - _C6 cycloalkyloxy. Examples include, but are not limited to, cyclopropanoxy and cyclobutanoxy. The group may be a terminal group or a bridging group. If the group is a terminal group, it is attached to the remainder of the molecule via an oxygen atom.

"Cycloalkenyloxy" refers to a cycloalkenyl-O- group, where cycloalkenyl is as defined herein. Preferably, the cycloalkenyloxy is a _C1 - _C6 cycloalkenyloxy. The group may be a terminal group or a bridging group. If the group is a terminal group, it is attached to the remainder of the molecule via an oxygen atom.

"Haloalkyl" refers to an alkyl group, as defined herein, in which one or more hydrogen atoms have been replaced with a halogen atom selected from the group consisting of fluorine, chlorine, bromine and iodine. Haloalkyl groups typically have the formula _{CnH (2n+1-m) Xm} , where each X is independently selected from the group consisting of F, Cl, Br and I. In groups of this type n is typically 1 to 10, more preferably 1 to 6, and most preferably 1 to 3. m is typically 1 to 6, more preferably 1 to 3. Examples of haloalkyl include fluoromethyl, difluoromethyl and trifluoromethyl.

"Haloalkenyl" refers to an alkenyl group, as defined herein, in which one or more hydrogen atoms are replaced with halogen atoms independently selected from the group consisting of F, Cl, Br, and I.

"Haloalkynyl" refers to an alkynyl group, as defined herein, in which one or more hydrogen atoms are replaced with halogen atoms independently selected from the group consisting of F, Cl, Br, and I.

"Halogen" refers to chlorine, fluorine, bromine or iodine.

"Heteroalkyl" refers to a straight or branched chain alkyl group preferably having 2 to 24 carbons, 2 to 18 carbons, 2 to 14 carbons, 2 to 12 carbons, 2 to 6 carbons in the chain, where one or more carbon atoms (and any associated hydrogen atoms) are each independently replaced with a heteroatom group selected from S, O, P, and NR', where R' is selected from the group consisting of H, optionally substituted _C1 - _C12 alkyl, optionally substituted _C3 - _C12 cycloalkyl, optionally substituted _C6 - _C18 aryl, and optionally substituted _C1 - _C18 heteroaryl. Exemplary heteroalkyls include alkyl ethers, secondary and tertiary alkyl amines, amides, alkyl sulfides, and the like. Examples of heteroalkyl also include hydroxyC ₁ -C ₆ alkyl, C ₁ -C ₆ alkyloxyC ₁ -C ₆ alkyl, aminoC ₁ -C ₆ alkyl, C ₁ -C ₆ alkylaminoC ₁ -C ₆ alkyl, and di(C ₁ -C ₆ alkyl)aminoC ₁ -C ₆ alkyl. The group may be a terminal or bridging group.

"Heteroalkyloxy" refers to a heteroalkyl-O- group where heteroalkyl is as defined herein. Preferably, the heteroalkyloxy is a _C2 - _C6 heteroalkyloxy. The group may be a terminal or bridging group.

"Heteroaryl" either alone or as part of a group refers to a group containing an aromatic ring (preferably a 5- or 6-membered aromatic ring) having one or more heteroatoms as ring atoms in the aromatic ring, the remainder of the ring atoms being carbon atoms. Suitable heteroatoms include nitrogen, oxygen and sulfur. The group may be a monocyclic or bicyclic heteroaryl group. Examples of heteroaryls include thiophene, benzothiophene, benzofuran, benzimidazole, benzoxazole, benzothiazole, benzisothiazole, naphtho[2,3-b]thiophene, furan, isoindolizine, xanthrene, phenoxathine, pyrrole, imidazole, pyrazole, pyridine, pyrazine, pyrimidine, pyridazine, tetrazole, indole, isoindole, 1H-indazole, purine, quinolinol, phenylalanine ... Heteroaryl groups include 2-, 3- or 4-pyridyl, 2-, 3-, 4-, 5- or 8-quinolyl, 1-, 3-, 4- or 5-isoquinolinyl, 1-, 2- or 3-indolyl and 2- or 3-thienyl. Heteroaryl groups are typically C ₁ -C ₁₈ heteroaryl groups. The groups may be terminal or bridging groups.

"Heteroarylalkyl" means a heteroarylalkyl group in which the heteroaryl and alkyl moieties are as defined herein. Preferred heteroarylalkyl groups contain a lower alkyl moiety. Exemplary heteroarylalkyl groups include pyridylmethyl. The group may be a terminal group or a bridging group. When the group is a terminal group, it is attached to the remainder of the molecule via the alkyl group.

"Heteroarylalkenyl" means a heteroarylalkenyl group in which the heteroaryl and alkenyl moieties are as defined herein. The group may be a terminal group or a bridging group. When the group is a terminal group, it is attached to the remainder of the molecule via the alkenyl group.

"Heteroarylheteroalkyl" means a heteroarylheteroalkyl group, where the heteroaryl and heteroalkyl moieties are as defined herein. The group may be a terminal group or a bridging group. If the group is a terminal group, it is attached to the remainder of the molecule via the heteroalkyl group.

"Heteroaryloxy" refers to the group heteroaryl-O-, where heteroaryl is as defined herein. Preferably, the heteroaryloxy is a _C1 - _C18 heteroaryloxy. The group may be a terminal group or a bridging group. If the group is a terminal group, it is attached to the remainder of the molecule via an oxygen atom.

"Heterocyclic" refers to a saturated, partially unsaturated or fully unsaturated monocyclic, bicyclic or polycyclic ring system containing at least one heteroatom selected from the group consisting of nitrogen, sulfur and oxygen as a ring atom. Examples of heterocyclic moieties include heterocycloalkyl, heterocycloalkenyl and heteroaryl.

"Heterocycloalkenyl" refers to a heterocycloalkyl group, as defined herein, but containing at least one double bond. Heterocycloalkenyl groups are typically _C2 - _C12 heterocycloalkenyl groups. The group may be a terminal or bridging group.

"Heterocycloalkyl" refers to a saturated monocyclic, bicyclic or polycyclic ring containing at least one heteroatom, preferably 1 to 3 heteroatoms, selected from nitrogen, sulfur or oxygen in at least one ring. Each ring is preferably 3 to 10 members, more preferably 4 to 7 members. Examples of suitable heterocycloalkyl substituents include pyrrolidyl, tetrahydrofuranyl, tetrahydrothiofuranyl, piperidyl, piperazyl, tetrahydropyranyl, morphilino, 1,3-diazapane, 1,4-diazapane, 1,4-oxazepane and 1,4-oxathiapane. Heterocycloalkyl groups are typically _C2 to _C12 heterocycloalkyl groups. The group may be a terminal or bridging group.

"Heterocycloalkylalkyl" refers to a heterocycloalkyl-alkyl group in which the heterocycloalkyl and alkyl moieties are as defined herein. Exemplary heterocycloalkylalkyl groups include (2-tetrahydrofuranyl)methyl, (2-tetrahydrothiofuranyl)methyl. The group may be a terminal group or a bridging group. When the group is a terminal group, it is attached to the remainder of the molecule via the alkyl group.

"Heterocycloalkylalkenyl" refers to a heterocycloalkyl-alkenyl group in which the heterocycloalkyl and alkenyl moieties are as defined herein. The group may be a terminal group or a bridging group. When the group is a terminal group, it is attached to the remainder of the molecule via the alkenyl group.

"Heterocycloalkylheteroalkyl" means a heterocycloalkyl-heteroalkyl group, where the heterocycloalkyl and heteroalkyl moieties are as defined herein. The group may be a terminal group or a bridging group. If the group is a terminal group, it is attached to the remainder of the molecule via the heteroalkyl group.

"Heterocycloalkyloxy" refers to a heterocycloalkyl-O- group, where heterocycloalkyl is as defined herein. Preferably, the heterocycloalkyloxy is a _C1 - _C6 heterocycloalkyloxy. The group may be a terminal group or a bridging group. If the group is a terminal group, it is attached to the remainder of the molecule via an oxygen atom.

"Heterocycloalkenyloxy" refers to a heterocycloalkenyl-O- group, where heterocycloalkenyl is as defined herein. Preferably, the heterocycloalkenyloxy is a _C1 - _C6 heterocycloalkenyloxy. The group may be a terminal group or a bridging group. If the group is a terminal group, it is attached to the remainder of the molecule via an oxygen atom.

"Hydroxyalkyl" refers to an alkyl group, as defined herein, in which one or more hydrogen atoms have been replaced with an OH group. Typically, a hydroxyalkyl group has the formula _{CnH (2n+1-x)} (OH) _x . In groups of this type, n is typically 1 to 10, more preferably 1 to 6, and most preferably 1 to 3. x is typically 1 to 6, more preferably 1 to 3.

"Sulfinyl" refers to the group R-S(=O)-, where R can be OH, alkyl, cycloalkyl, heterocycloalkyl; aryl or heteroaryl as defined herein. The group can be a terminal group or a bridging group. When the group is a terminal group, it is attached to the remainder of the molecule through a sulfur atom.

"Sulfinylamino" refers to the group R-S(=O)-NH-, where R can be OH, alkyl, cycloalkyl, heterocycloalkyl; aryl or heteroaryl as defined herein. The group can be a terminal group or a bridging group. When the group is a terminal group, it is attached to the remainder of the molecule through the nitrogen atom.

"Sulfonyl" refers to the group RS(=O) _2- , where R can be OH, alkyl, cycloalkyl, heterocycloalkyl; aryl or heteroaryl as defined herein. The group can be a terminal or bridging group. When the group is a terminal group, it is attached to the remainder of the molecule via a sulfur atom.

"Sulfonylamino" means the group RS(=O) _2- NH-. The group may be a terminal group or a bridging group. If the group is a terminal group, it is attached to the remainder of the molecule via the nitrogen atom.

The prior art cited herein is hereby incorporated by reference.

Preferred embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings in which:

1 is a graph showing the results of Example 1, showing the change in gel density (g.cm ⁻³ ) over time (days) including a range of density stabilised H ₂ O ₂ with phosphonate, DTMPMA.Na.X (wt %). FIG. 1 is a graph showing the results of Example 1, showing the loss of gel density (% of initial) over time (days) compared to the initial density, including a range of density-stabilized _H2O2 with phosphonate, _DTMPMA.Na.X (wt%). 1 is a graph showing the results of Example 2, showing the average velocity of detonation (VOD) for open detonations (n=3) of varying densities of _H2O2 / _glycerin -based explosive formulations augmented with 3 wt% DTMPMA, sensitized with 3M™ K15 Glass Micro-Balloons in a 47 mm diameter pipe, and initiated with a 25 g Pentex D Booster. Two VOD monitors, VOD1 (dotted line) and VOD2 (dashed line), were connected to each blast, and the average of the VOD data is displayed as the solid line. Figure 1 shows the change in gel density (g.cm ^-3 ) over 10 days between 0 and 5 wt% PA. Error bars are standard deviation (n=4). 3, 4 and 5 wt% PA formulations disintegrated in 5 days. Figure 1 is a graph showing loss of gel density (%) compared to initial density over 10 days between 0 and 5 wt% PA. Error bars are standard deviation (n=4). 3, 4 and 5 wt% PA formulations disintegrated in 5 days. Figure 1 is a graph showing the change in gel density (g.cm ^-3 ) over 13 days between 0 and 2 wt% PA. Error bars are standard deviation (n=4). FIG. 1 is a graph showing loss in gel density (%) compared to initial density over 13 days between 0 and 2 wt% PA. Error bars are standard deviation (n=4).

The present invention relates to
a. _{H2O2 ;}
b. Fuel; and
c. Providing an explosive composition comprising one or more density stabilizers.

In one embodiment, the compositions of the present invention are formulated as hydrogels. In an alternative embodiment, the compositions of the present invention are formulated as emulsions.

Hydrogen _peroxide ( _H2O2 )
The preferred concentration _{of H2O2} in the compositions of the present invention is about 2% to 85% by weight. By way of example only, concentrated _H2O2 solutions (70% by weight) can be procured and diluted to 25% by weight for use in the compositions. Other possibilities will be apparent to those skilled in the art. Preferably, the _H2O2 concentration in the composition is approximately ₂ , ₃ , 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80 or 85% (w/w). Preferably, _{the H2O2} concentration in the composition is between about 2-3, 3-5, 5-10, 10-15, 15-20, 20-25, 25-30, 30-35, 35-40, 40-45, 45-50, 50-55, 55-60, 60-65, 65-70, 70-75, 75-80 or 80-85% (w/w).

It will be understood that the weight percent of hydrogen peroxide present in the composition refers to the amount of pure hydrogen peroxide. Since hydrogen peroxide is provided in the form of an aqueous solution having a H ₂ O ₂ concentration _less than 100%, for example, 50% by weight, or 35% by weight, or 30% by weight, those skilled in the art will readily understand the need and the manner in which they can adjust the amount of dilute _{H 2} O ₂ solution required to ensure that the explosive composition of the present invention contains 2-25% by weight _of H ₂ O _2. To avoid doubt _, by way of example, if the composition of the present invention contains 20% of a 50% by weight solution of H 2 O 2, the composition will contain 10% by weight of H ₂ O _2. Those skilled in the art will also recognize that the concentration of 2-85% by weight of H ₂ O ₂ is the final H ₂ O ₂ concentration in the explosive composition, and therefore must take into account the dilution effect of other components (e.g., fuel, oxidizer, thickener, etc.) added to the composition during formulation.

Water The explosive compositions described herein may comprise water. In one embodiment, the explosive composition may comprise less than 50% water by weight, or 40% or less water, or 30% or less water, such as 25% or less, 20% or less, 15% or less or 10% or less water, by weight. In one embodiment, the explosive composition may comprise 5% or more water, such as 10% or more water, by weight. The composition may thus comprise 5-50% water, or 5-20% water, or 15-30% water, or 10-40% water, or 50, 45, 40, 35, 30, 25, 20, 15, 10, 5 or 1% water by weight.

Sensitizers The explosive composition according to the present invention may include one or more sensitizers dispersed in the composition to generate voids that improve the sensitivity to detonation. Furthermore, _H2O2 itself can act as both a sensitizer and an _oxidizer . Alternatively, _{H2O2 itself} can act as a sensitizer and no other sensitizers may be used.

Sensitizers include in situ generated gas bubbles or injected air, or air/gas entrapped materials. Another example of sensitization is a combination of both gas bubbles (chemically generated or injected) and air entrapped materials.

The explosive composition of the present invention includes a discontinuous gaseous component for sensitizing the composition.

The present invention provides explosive compositions and relies on the sensitization of _{H2O2 based} compositions to control key factors such as the explosive sensitivity, density, velocity of detonation (VOD) and energy delivery of the detonation.

Preferably, the explosive composition of the present invention is adapted to maintain the sensitizer in a substantially homogeneous dispersion (e.g., by means of a thickener or emulsifier in the case of a hydrous gel or emulsion, respectively). It will be appreciated that various techniques may be utilized to achieve this property, as discussed further below.

Preferably, a minimum concentration of sensitizer is included in the composition to render it explosive. Preferably, the sensitizer is included in a detonation sensitive concentration or amount. The sensitizer is also preferably maintained in a detonation sensitive dispersion/distribution throughout the composition. Preferably, the final density of the composition is controlled to an initial desired predetermined explosive range. Preferably, the final density is controlled with the sensitizer to about 0.6 to about 1.15 g/ml. Preferably, the composition is formulated to have a density of approximately 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.1, 1.2, 1.3, or 1.4 g/ml. Preferably, the density of the composition is initially formulated to be between about 0.1-0.2, 0.2-0.3, 0.3-0.4, 0.4-0.5, 0.5-0.6, 0.6-0.7, 0.7-0.8, 0.8-0.9, 0.9-1.0, 1.0-1.1, 1.1-1.2, 1.2-1.3, 1.3-1.4, or 1.4-1.5 g/ml. However, it will be appreciated that for some applications, other high density additives can be included to specifically increase the density up to 1.6, 1.7, 1.8, 1.9, or 2.0 g/ml. Preferably, the density is maintained or stabilized as discussed above over an extended period of time, thereby increasing sleep time as compared to explosive compositions that do not include a density stabilizer as discussed herein.

Those skilled in the art will appreciate that mathematical conversions are required to convert the mass of mechanical sensitizers, such as ceramic/glass/plastic microballoons or expanded polystyrene spheres, or the amount of chemical agent broken down into bubbles to volume (as void space) to obtain a constant density. However, it will be appreciated that regardless of the type of sensitizer, the final density is controlled to a predetermined value to obtain an explosive composition, thereby controlling the parameters discussed above.

Many advantages derive from the explosive compositions of the invention taught herein. For example, certain formulations of the compositions of the invention are more cost-effective and can be manufactured in large quantities to meet the demands of the mining industry, as compared to existing explosive compositions. The explosive _compositions of the invention utilize _H2O2 , _which is a sustainably produced material with a relatively low carbon footprint, as compared to other types _of oxidizers used in the industry. The explosive compositions of the invention can also be formulated into slurries, pellets, beads, or emulsion forms. It will also be appreciated that the compositions of the invention have reduced amounts of _NOx , and in preferred forms of the invention, are completely free of _NOx . Other advantages include density stabilization over long periods of time (as compared to explosive compositions without density stabilizers as described herein), thereby allowing for improved sleep times and blast performance that would not be possible with _{H2O2 -} based explosive compositions without density stabilizers.

Once the explosive has been sensitized, it can be initiated by a detonator/booster, which, as one skilled in the art knows, creates a high detonation pressure in the explosive, which then initiates the detonation of the sensitized explosive.

Introduction of voids into the composition can be achieved by a variety of techniques, all of which are applicable to the present invention, including by trapping gas bubbles during mixing, by using chemically generated gas bubbles in situ, by injecting gas bubbles, or by mixing the composition with a material that traps gas.

Examples of air-trapping materials that can be used in combination with gas bubbles to sensitize hydrogen peroxide-based explosives include glass or plastic microballoons, expanded polystyrene beads, polyurethane foam, etc.

Preferably, these void components are incorporated into the compositions of the present invention as fine gas bubbles dispersed throughout the composition. They may also include hollow gas-filled compressible particles, such as microballoons, or porous particles, or mixtures thereof.

A discontinuous phase of fine gas bubbles may be incorporated into the compositions of the present invention by mechanical agitation, injection by bubbling the gas through the composition, or in situ generation of gas by chemical means.

Suitable chemicals for in situ generation of gas bubbles include _H2O2 itself, which can be decomposed using manganese (Mn ₎ salts, yeast, iodide salts, etc.; nitrogen-based compounds such as sodium nitrite, etc.; nitrosamines such as N,N'-dinitrosopentamethylenetetramine, etc.; boron-based compounds such as sodium borohydride, etc.; carbonates such as sodium carbonate, etc. In situ decomposition of a portion of hydrogen peroxide with permanganate (etc.) forms oxygen gas bubbles. In situ decomposition of carbonates with acid forms carbon dioxide bubbles.

Examples of suitable hollow particles include small hollow microspheres of glass and resinous materials such as phenol-formaldehyde, poly(vinylidene chloride)/poly(acrylonitrile) copolymers, and urea formaldehyde. Examples of suitable hollow particles include Q-Cel, Cenospheres, Expancel, 3M, Extendospheres, and the like. Examples of porous materials include hollow particles of expanded minerals such as perlite, fly ash, or by-products of coal-fired power plants.

Typically, sufficient void space/gas bubbles (possibly including hollow and/or porous particles) are used in the compositions of the present invention to provide an explosive composition having a density in the range of 0.1 to 1.4 g/cm ^3. In a preferred embodiment, sensitization is provided entirely from the gas bubbles, provided that no hollow gas-filled compressible particles are present.

When conventional mixing techniques are used to introduce bubbles into emulsion explosive compositions, bubbles with a wide range of bubble sizes are often produced. For example, bubbles often have diameters up to 2000 microns, with average bubble diameters of less than 50 microns being common. Smaller or larger diameter bubbles can be produced by the selection of an appropriate surfactant. Thus, by choosing a suitable surfactant at the desired concentration, the average gas bubble diameter in the discontinuous gas phase can be controlled, and bubbles of 50 to 200 microns can be obtained. It is understood that the size of the bubbles affects the overall density, and where low density is required, gas bubbles of 50 to 100 microns are preferred. For emulsified explosives, the density range is preferably approximately 0.60 to 1.20 g/ml, and for hydrogels, the density range is preferably between 0.2 and 1.2 g/ml. In an emulsified system, the gas bubbles are preferably 10 to 100 times larger than the dispersed phase droplets. The oil phase tends to come into contact with the gas bubbles, whereas the oxidizer (or discontinuous phase) does not.

As discussed above, the introduction of gas bubbles can be achieved by a variety of techniques, all of which are applicable to the present invention.

In one embodiment, the bubbles may be "trapped" upon their formation by chemical reaction during the preparation of the explosive composition. US Patent No. 3,400,026 describes a formulation using proteins (albumin, collagen, soy protein, etc.) in solution to facilitate the formation of bubbles and their stabilization. US Patent No. 3,582,411 describes a hydrogel formulation containing a foaming agent of guar gum type modified with hydroxy groups. US Patent No. 3,678,140 describes a method of incorporating air by using a protein solution by passing the composition through a series of openings at a pressure of 40 to 200 psi while simultaneously introducing air by an eductor.

The incorporation of gas bubbles generated as a result of chemical reactions has also been described in the prior art: the in situ generation of gas bubbles results from the decomposition of chemical compounds, suitably producing _O2 , _CO2 , _N2 , _H2 or combinations thereof.

Various gases in bubble form, such as nitrogen, carbon dioxide, oxygen and hydrogen, have been used to sensitize blasting agents. It is also known to inject air or gas directly into the explosive mixture. Gases suitable for injection include air, oxygen, nitrogen, carbon dioxide, hydrogen and the noble gases (such as argon).

Alternatively, hollow gas-filled compressible particles, such as glass or plastic microballoons, or porous particles, or expanded polystyrene (EPS), or mixtures thereof, are included. In a related embodiment, the compressible material is any low-density material with a specific gravity of <1.0 g/ ^cm3 . Briefly, examples of glass balloons can be found in US Pat. Nos. 4,326,900 and 3,447,978, and examples of plastic microballoons can be found in US Pat. Nos. 4,820,361 and 4,547,234. These balloons are typically 0.05 mm in diameter and have a bulk density of 100 g/L. The use of expanded polystyrene can be found, for example, in US Pat. Nos. 5,470,407 and 5,271,779.

In one embodiment, the compressible material is gas-filled and is selected from small hollow microspheres of ceramic, glass or resinous materials or porous materials and combinations thereof, such as perlite or fly ash.

Preferably, the microspheres/microballoons contain a gas, such as pentane. Suitably, the microspheres are about 20-2000 microns in size and have a bulk density of less than 1000 g/L.

In alternative embodiments, the compressible material is a foam material, such as expanded polystyrene (EPS), polyurethane foam, cottonseed, expanded popcorn, husks, and combinations thereof.

Examples of suitable hollow particles include small hollow microspheres of ceramic, glass and resinous materials such as phenol formaldehyde, poly(vinylidene chloride)/poly(acrylonitrile) copolymers and urea formaldehyde. Examples of suitable hollow particles include Q-Cel, Envirospheres®, Cenospheres®, Expancel®, 3M, Extendospheres®, and the like. Examples of porous materials include expanded minerals such as perlite, fly ash, and the like. A further example of a porous material is hollow particles that are a by-product of coal-fired power plants.

Typically, sufficient bubbles, and/or hollow particles, and/or porous particles are used in the compositions of the present invention to obtain an explosive composition having a density in the range of 0.3 to 1.4 g/cm ³ .

For example, the explosive composition of the present invention may have a density of up to 1.4 g/cm ³ , up to 1.3 g/cm ³ , up to 1.2 g/cm ³ , up to 1.1 g/cm ³ , up to 1.0 g/cm ³ , etc. The explosive composition of the present invention may have a density of 0.3 g/cm ³ or more, 0.4 g/cm ³ or more, 0.5 g/cm ³ or more, etc. The use of conventional mixing techniques to impart bubbles in emulsion explosive compositions often produces bubbles having a range of bubble sizes. For example, bubbles often have a diameter of up to 2000 microns, and average bubble diameters of less than 300 microns are also common. By selecting the appropriate surfactant, smaller or larger diameter bubbles can be produced. Thus, by choosing a suitable surfactant at the desired concentration, the average gas bubble diameter in the discontinuous gas phase can be controlled, and bubbles of 50 to 300 microns can be obtained. For emulsified explosives the density range is suitably around 0.60 to 1.30 g/ ^cm3 and for hydrous gels the density range is suitably between 0.2 and 1.40 g/ ^cm3 . In emulsified systems the gas bubbles are suitably 10 to 100 times larger than the dispersed phase droplets. The oil phase tends to be in contact with the gas bubbles whilst the oxidant (or discontinuous phase) is not.

Other types of sensitizing materials, such as TNT, HMX, RDX, aluminum powder, and silicon powder, and combinations thereof (e.g., TNT, HMX, RDX, and aluminum powder, and combinations thereof), can be used in the compositions of the present invention.

Density Stabilizer The explosive compositions of the present invention include at least one density stabilizer.

Typically, one or more density stabilizers are incorporated in an amount of up to about 15% by weight of the explosive composition, such as from about 0.01% to about 10% by weight, such as from about 1% to about 5% by weight, such as from about 1% to about 3% by weight. The one or more density stabilizers are preferably present in a concentration of about 0.01, 0.05, 0.1, 0.25, 0.5, 0.75, 1, 1.25, 1.5, 1.75, 2, 2.25, 2.5, 2.75, 3, 3.25, 3.5, 3.75, 4, 4.25, 4.5, 4.75, 5, 5.25, 5.5, 5.75, 6, 6.25, 6.5, 6.75, 7, 7.25, 7.5, 7.75, 8, 8.25, 8.5, 8.75, 9, 9.25, 9.5, 9.75, 10, 11, 12, 13, 14 or 15% by weight. The one or more density stabilizers are preferably present in a concentration of about 0.01-0.05, 0.05-0.1, 0.1-0.5, 0.5-1, 1-1.5, 1.5-2, 2-2.5, 2.5-3, 3-3.5, 3.5-4, 4-4.5, 4.5-5, 5-5.5, 5.5-6, 6-6.5, 6.5-7, 7-7.5, 7.5-8, 8-8.5, 8.5-9, 9-9.5, 9.5-10, 10-11, 11-12, 12-13, 13-14, or 14-15% by weight.

Preferably, the density stabilizer is present at about 0.01% to about 10% by weight, such as about 1% to about 5% by weight, for example about 1% to about 3% by weight.

The preferred density stabilizer is a phosphonate.

Phosphonate Preferably, the phosphonate is in liquid form (eg, dissolved in a solution).

The phosphonate may have 1, 2, 3, 4, 5, or 6 pendant phosphonate groups, or more than 6 groups. In some embodiments, the phosphonate may have 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 pendant phosphonate groups. Preferably, the phosphonate has at least 3 pendant phosphonate groups, more preferably 5 pendant phosphonate groups.

In certain embodiments, the phosphonate has the structure X-(PO ₃ Y ₂ ) _n , where X is selected from the group consisting of optionally substituted alkyl, optionally substituted heteroalkyl, optionally substituted cycloalkyl, optionally substituted heterocycloalkyl, optionally substituted alkenyl, optionally substituted aryl, and optionally substituted heteroaryl; Y is H or a water soluble cation; and n is 1 to 10 (i.e., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10). Suitable optional substituents may be selected from the group consisting of -OH, -COOH, halogen, -NH ₂ , and -SH. In a preferred embodiment, the phosphonate has the structure X-(PO ₃ Y ₂ ) _n , where X is an optionally substituted heteroalkyl, an optionally substituted heterocycloalkyl, or an optionally substituted heteroaryl having at least two nitrogen atoms, preferably at least three nitrogen atoms, more preferably three nitrogen atoms; Y is H or a water soluble cation; and n is 1 to 10 (i.e., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10). Suitable optional substituents may be selected from the group consisting of -OH, -COOH, halogen, -NH ₂ , -SH.

In some preferred embodiments, the phosphonates suitable for use in the present invention are amine-based, more preferably tertiary amine-based.

Water soluble cations suitable for the phosphonate anion include alkali metals (e.g. lithium, sodium, potassium), ammonium, substituted ammonium and alkaline earth metals (e.g. calcium, magnesium). Preferred compounds have n=1-2, preferably Y is hydrogen, ammonium, sodium or potassium or mixtures thereof. In one preferred embodiment, the density stabilizer is a phosphonate which is _{diethylenetriaminepentamethylenephosphonic} acid _sodium salt (DTPMPA.Na.x, _{C9H28 - xN3O15P5Nax} ) _. See Formula I below.

Other suitable examples of phosphonates include those within the scope of Formula II:

The various X groups may be the same or different.

Other examples of suitable phosphonates include the following, and their salts, solvates, dimers and stereoisomers:

Without being bound by any one theory, the inventors believe that suitable phosphonates used in the present invention stabilize density by chelating or sequestering impurities inherently present in the explosive compositions contemplated herein (i.e., providing "internal" stability). In addition, suitable phosphonates used in the present invention stabilize density by chelating or sequestering impurities that arise when the explosive composition is loaded into a blast hole and exposed to rock (i.e., providing "external" stability). It will be appreciated that the explosives of the present invention may be used in a wide range of surface and subsurface applications and in a range of different types of rocks having various metal-containing mineralogy. One or more phosphonates described herein may be selected for use depending on the type of impurities (metal ions) present in the rock to be blasted and/or depending on whether the application is in a high temperature reactive terrain that may affect the solubility and/or pH of the metal ions.

Composition Stabilizers Other composition stabilizers may also be used in the present invention.

Suitable composition stabilizers may be selected from the group consisting of phosphates, stannates and sulfites.

Suitable composition stabilizers also include EDTA and nitrates (e.g., sodium nitrate or potassium nitrate).

For example, stannates, sulfites and nitrates, such as mixtures of phosphonates and nitrates, can be used either as separate components or as components of the density stabilizing system.

Typically, other composition stabilizer components of the compositions of the present invention are incorporated in an amount of up to about 15% by weight, such as from about 0.01% to about 10% by weight, such as from about 1 to about 5% by weight, e.g., from about 1 to about 3% by weight of the total composition.

Fuels for Hydrous Gels The explosive compositions of the present invention may contain one or more fuels.

_{H2O2 -} based hydrous gels can be prepared using either water-miscible or water-immiscible fuels.

The skilled artisan will recognize that there are many options available for use as fuel. For example, the fuel may be a product of vegetable origin, such as sugar, molasses, vegetable oil or alcohol, depending on its origin. Such fuels may be considered sustainable fuels. Other fuels may be sourced from the petrochemical industry, for example diesel fuel, paraffin oil or mineral oil, organic acids, ethers, esters, amine nitrates, urea, hexamine, etc. Other fuels may be silicone oils, etc. Suitable fuels for use in the compositions of the present invention are glycerin, sugar, syrup, alcohol, carbon, pulverized coal, wax, oleaginous, such as corn, cottonseed, olive, peanut or fatty acid oils. Suitable sustainable fuels for use in the compositions of the present invention may include molasses, vegetable oils, alcohol, oleaginous, such as corn, cottonseed, olive, peanut, fatty acid oils or rubber. Other fuels may be selected from ethylene glycol, glycerin, propylene glycol, and/or formamide. Preferably the sustainable fuel is glycerin. The composition may comprise between 15 and 25% by weight of sustainable fuel, for example between 15 and 20% or between 20 and 25% by weight. The composition may alternatively comprise less than 40% by weight of sustainable fuel, less than 30%, less than 25% or less than 20% by weight of sustainable fuel, for example 5%, 10%, 15%, 20%, 25%, 30%, 35% or 40% by weight of sustainable fuel. Alternatively, the fuels mentioned above may be divided into water-soluble and water-insoluble fuels.

The water-miscible fuel that can be used in the present invention can be selected from the group consisting of glycerin, sugar, amine nitrate, hexamine and urea.

The water-immiscible fuels that can be used in the present invention can be selected from the group consisting of aliphatic, cycloaliphatic and aromatic compounds and mixtures thereof that are liquid at the blending temperature. Suitable organic fuels can be selected from fuel oils, diesel oils, distillates, kerosene, naphtha, waxes (e.g., microcrystalline wax, paraffin wax and slack wax), paraffin oils, benzene, toluene, xylene, asphaltic materials, polymeric oils (e.g., low molecular weight polymers of olefins, etc.), vegetable oils, animal oils, fish oils, and other mineral oils, hydrocarbons or fatty oils, and mixtures thereof. Preferred organic fuels are liquid hydrocarbons, commonly referred to as petroleum distillates, such as gasoline, kerosene, fuel oils, paraffin oils, vegetable oils, or mixtures thereof.

Typically, the water-miscible or water-immiscible fuel of the hydrogel composition of the present invention comprises 5-30% by weight, preferably 10-25% by weight, of the total composition. Preferably, the fuel is present at a concentration of about 5, 7, 8, 10, 12, 15, 20, 25, 30, 35, 40, 45 or 50% (w/w). Preferably, the fuel is present at a concentration between about 5-10, 10-15, 15-20, 20-25, 25-30, 30-35, 35-40, 40-45 or 45-50% (w/w).

In one embodiment, the water-immiscible fuel comprises 7-25% by weight of the total composition.

In one embodiment, the water-miscible fuel comprises 8-25% by weight of the total composition.

Fuels for the Emulsions The explosive compositions of the present invention may contain one or more fuels.

_H2O2 - _based emulsions can be prepared using fuels that are immiscible in water.

The fuels may be any fuel, such as diesel fuel and/or oleochemical distillates. Alternatively, they may be paraffinic, mineral, olefinic, naphthenic, animal, vegetable, fish and silicone oils. Other types of fuels are benzene, toluene, xylene, asphaltic materials, etc. The fuel may be a sustainable fuel. Suitable sustainable fuels for use in the emulsion may include oils such as vegetable oils, corn, cottonseed, olive, peanut or fatty acid oils. The composition may include 15 to 25% by weight, such as between 15 and 20% or between 20 and 25% by weight of a sustainable fuel. The composition may alternatively include less than 40% by weight of a sustainable fuel, less than 30%, less than 25%, or less than 20% by weight of a sustainable fuel, such as 5%, 10%, 15%, 20%, 25%, 30%, 35% or 40% by weight of a sustainable fuel.

The water immiscible organic phase component of the compositions of the present invention comprises the continuous "oil" phase of the water-in-oil emulsion and is a fuel. Suitable organic fuels include aliphatic, cycloaliphatic and aromatic compounds and mixtures thereof that are liquid at the blending temperature. Suitable organic fuels can be selected from recycled lubricant distillates, recycled oil distillates, fuel oils, diesel oils, distillates, kerosene, naphtha, waxes (e.g., microcrystalline wax, paraffin wax and slack wax), paraffin oils, benzene, toluene, xylene, asphaltic materials, polymeric oils such as low molecular weight polymers of olefins, vegetable oils, animal oils, fish oils, and other mineral, hydrocarbon or fatty oils, and mixtures thereof. Preferred organic fuels are liquid hydrocarbons commonly referred to as petroleum distillates, e.g., gasoline, kerosene, fuel oils, paraffin oils, vegetable oils or mixtures thereof.

Typically, the organic fuel or continuous phase of the _{H2O2 -} based emulsion compositions of the present invention comprises 2-20% by weight of the total composition, preferably 3%-20% by weight. Preferably, the organic fuel is present at a concentration of about 2, 4, 6, 8, 10, 12, 14, 16, 18, or 20% (w/w). Preferably, the organic fuel is present at a concentration between about 2-4, 4-6, 6-8, 8-10, 10-12, 12-14, 14-16, 16-18, or 18-20% (w/w).

Secondary Fuels for Hydrogels and Emulsions If desired, other optional fuel materials (hereinafter referred to as secondary fuels) can be incorporated into the compositions of the present invention.

Examples of secondary fuels include finely divided solids. Examples of secondary fuels also include water-miscible organic liquids. Examples of solid secondary fuels include sulfur; aluminum; and carbonaceous materials such as gilsonite, finely divided coke or charcoal, carbon black, resin acids such as abietic acid, plant products such as starch, nut foods, grain foods, and wood pulp, and combinations thereof. Examples of secondary fuels include sugars such as glucose and dextrose. Examples of secondary fuels further include recycled plastic waste.

Typically, the optional second fuel component of the composition of the present invention comprises 0-20% by weight, for example 0.1-12% by weight, of the total composition.

Thickening Agents The explosive composition of the present invention may contain one or more thickening agents. In particular, the hydrogel composition of the present invention may contain one or more thickening agents.

Because the gas bubbles and the material surrounding the gas are relatively low density, if the viscosity of the _{H2O2 -} based explosive composition is not able to keep the sensitizing material homogeneously dispersed throughout, the sensitizing material will tend to migrate toward the surface of the explosive column. This migration of the sensitizing material to the surface is undesirable because it can cause the explosive to become too insensitive to detonate, and therefore the explosive composition cannot deliver the energy and gas required to excavate and move the rock required, or even worse, can cause the explosive to misfire. One way to remedy this problem is to formulate the explosive composition into a hydrogel. These types of compositions can be formulated at various levels of viscosity by using thickening agents. The viscosity can generally be selected to keep the sensitizing material homogeneously dispersed throughout the composition.

If desired, the aqueous solution of the composition of the present invention may contain a thickening agent, which may optionally be crosslinked. Any conventional thickening agent may be used in the present invention. When used in the composition of the present invention, the thickening agent is suitably a polymeric material, in particular a rubber material represented by galactomannan gum, such as locust bean gum or xanthan gum, or an alginate gum or a derivative of an alginate gum or a guar gum or a derivative thereof, such as hydroxypropyl guar gum. The thickening agent may be selected from gums including natural gums, such as guar gum, xanthan gum, sodium alginate, carboxymethylcellulose, methylcellulose, etc. Other useful but less preferred gums are the so-called biopolymer gums, such as heteropolysaccharides prepared by microbial transformation of carbohydrate materials, for example the processing of glucose with plant pathogens of the genus Xanthomonas, represented by Xanthomonas campestris. Other useful thickening agents include synthetic polymeric materials, in particular synthetic polymeric materials derived at least in part from the monomeric acrylamide. An example of a synthetic thickener is polyacrylamide. Inorganic thickeners such as fumed silica, clay and carbosil or combinations thereof can also be used. Suitably, the thickener is selected from locust bean gum, guar gum, hydroxypropyl guar gum, sodium alginate and heteropolysaccharides, and combinations thereof.

Typically, the thickener component of the composition of the present invention comprises 0-5% by weight of the total composition, such as 0.5-5% by weight, for example 0-2% by weight of the total composition, for example 0.1-2% by weight of the total composition.

Crosslinking Agents In the present invention, a crosslinking agent may also be used.

Thickeners can be combined with crosslinkers to improve the water resistance and mechanical strength of explosives. It is convenient for this purpose to use conventional crosslinkers, either as separate components, such as zinc chromate or dichromate, or as components of redox systems, such as mixtures of potassium dichromate and potassium antimony tartrate. Salts of Ca, Ti, Sb can also be used as crosslinkers.

In one embodiment, the crosslinking agent is selected from salts containing zinc, calcium, titanium, antimony, chromium, borate and dichromate, and combinations thereof.

Typically, the crosslinker component of the composition of the present invention comprises 0-3% by weight, such as 0-0.1% by weight of the total composition, such as 0.1-1% by weight of the total composition, such as 1-2% by weight of the total composition, such as 2-3% by weight of the total composition.

Emulsifiers When prepared in emulsion form, the explosive compositions of the present invention may contain one or more emulsifiers.

_H2O2 - _based emulsion compositions are made of a discontinuous phase of oxidizable material dispersed in a continuous phase of organic fuel in the presence of one or more emulsifiers adapted or selected to maintain phase separation.

The emulsifier component of the compositions of the present invention may be selected from a wide range of emulsifiers known in the art for the preparation of water-in-oil emulsion explosive compositions. Examples of such emulsifiers include polyisobutylene succinic anhydride reacted with amines (PIBSA); examples of other emulsifiers are alcohol alkoxylates, phenol alkoxylates, poly(oxyalkylene) glycols, poly(oxyalkylene) fatty acid esters, amine alkoxylates, fatty acid esters of sorbitol and glycerin, fatty acid salts, sorbitan esters, poly(oxyalkylene) sorbitan esters, fatty amine alkoxylates, poly(oxyalkylene) glycol esters, fatty acid amides, fatty acid amide alkoxylates, fatty amines, quaternary amines, alkyl oxazolines, alkenyl oxazolines, imidazolines, alkyl sulfonates, alkyl aryl sulfonates, alkyl sulfosuccinates, alkyl phosphates, alkenyl phosphates, phosphoric acid esters, lecithin, copolymers of poly(oxyalkylene) glycols and poly(12-hydroxystearic acid) and mixtures thereof.

Preferred emulsifiers include 2-alkyl- and 2-alkenyl-4,4'-bis(hydroxymethyl)oxazolines, fatty acid esters of sorbitol, lecithin, copolymers of poly(oxyalkylene) glycols and poly(12-hydroxystearic acid), and mixtures thereof, in particular sorbitan monooleate, sorbitan sesquioleate, mixtures of 2-oleyl-4,4'-bis(hydroxymethyl)oxazolines, sorbitan sesquioleate, lecithin, and copolymers of poly(oxyalkylene) glycols and poly(12-hydroxystearic acid), and mixtures thereof.

Typically, the emulsifier component of the compositions of the present invention comprises up to 5% by weight of the total composition. Higher percentages of emulsifier may be used and may serve as a supplemental fuel for the composition, but generally it is not necessary to add more than 5% by weight of emulsifier to achieve the desired effect. One advantage of the compositions of the present invention is that relatively low levels of emulsifier can be used to form stable emulsions, and for economic reasons it is preferred to keep the amount of emulsifier used to the minimum required to achieve the desired effect. The preferred level of emulsifier used is in the range of 0.1-2.0% by weight of the total composition.

Surfactants The explosive composition of the present invention, when formulated as a hydrous gel, may contain one or more surfactants, particularly when the explosive composition contains a fuel such as diesel fuel.

The surfactant component of the compositions of the present invention may be selected from the wide range of surfactants known in the art for the preparation of hydrogel and water-in-oil emulsion explosive compositions. Examples of such surfactants include sodium lauryl sulfate, betaine CAB30, sodium coconut sulfate (mono C12-C18 sodium alkyl sulfate), alpha olefin sulfate 46, coconut diethanolamide, APG0810 (octyldecyl glucoside), and cocamidopropyl betaine.

Typically, the surfactant component of the compositions of the present invention comprises up to about 0.5% by weight of the total composition, with about 0.25% by weight being used for cocamidopropyl betaine, another oxidizer for hydrogel and emulsion _{H2O2 -} based explosive compositions.

It is also within the scope of the present invention that one or more other substances or mixtures of substances suitable in themselves as explosives can be incorporated into the _{H2O2 -} based hydrogel/emulsion compositions described above.

Typical examples of such modified compositions include compositions in which up to 90% by weight of an oxidizing salt such as ammonium nitrate is added and mixed with the above-mentioned hydrogel/emulsion composition, or explosive compositions containing a mixture of an oxidizing salt such as ammonium nitrate and fuel oil, which are generally referred to by those skilled in the art as "ANFO". The composition of "ANFO" is well known and has been described in detail in the literature related to explosives.

In particular, the explosive composition of the present invention optionally includes one or more other oxidizers (e.g., one other oxidizer, e.g., two other oxidizers). Any suitable oxidizer may be used. For example, the one or more other oxidizers are suitably selected from the group consisting of nitrates, perchlorates, sodium peroxide and potassium peroxide, and optionally nitric acid.

The nitrate may be selected from the group consisting of ammonium nitrate, sodium nitrate, calcium ammonium nitrate, calcium nitrate, potassium nitrate, barium nitrate and magnesium nitrate.

The perchlorate may be selected from the group consisting of ammonium perchlorate, sodium perchlorate, potassium perchlorate, barium perchlorate, magnesium perchlorate and calcium perchlorate (e.g., ammonium perchlorate and sodium perchlorate).

In one embodiment, the one or more other oxidizing agents are selected from the group consisting of nitrates and perchlorates. In one embodiment, the one or more other oxidizing agents are selected from nitrates. In one embodiment, the one or more other oxidizing agents are selected from the group consisting of AN, CAN, and SN. In one embodiment, the one or more other oxidizing agents are selected from the group consisting of CAN, CN, and SN. In one embodiment, the one or more other oxidizing agents are selected from the group consisting of CAN and SN. In one embodiment, the other oxidizing agent is CAN. In one embodiment, the other oxidizing agent is SN. In one embodiment, the other oxidizing agent is CN. In one embodiment, the one or more other oxidizing agents does not include AN. In other words, in one embodiment, the explosive composition does not include AN.

The compositions of the present invention include one or more other oxidizing agents in an amount of from greater than 0 to about 90% by weight, such as from about 0.1% to about 75% by weight. For example, the compositions of the present invention may include from greater than 0, greater than 0.1%, greater than 1%, greater than 10%, greater than 20%, greater than 30%, greater than 40%, greater than 50%, or greater than 60% to up to 90% by weight of one or more other oxidizing agents, for example, the compositions of the present invention may include from 1 to 20%, 20 to 40%, 15 to 35%, 35 to 55%, 30 to 70%, 40 to 70%, or 50 to 80% by weight of one or more other oxidizing agents. For example, the compositions of the present invention may include up to 90%, 80%, 75%, 70%, 65%, 60%, 50%, 40%, 30%, 20% by weight of one or more other oxidizers, or may include about 90%, 80%, 75%, 70%, 65%, 60%, 55%, 50%, 45%, 40%, 30%, or 20% by weight of one or more other oxidizers. It will be understood that the explosive compositions herein include one or more oxidizers in total in the amounts or ranges set forth above, and as such, when multiple oxidizers are used, each oxidizer may be present in any suitable amount within the amounts or ranges set forth above such that the total mass of the oxidizers is the given amount or range.

It will be appreciated that the oxidizer may be in the form of a mixture of solid and liquid. By way of explanation, typically, the oxidizer is solubilized in water when used at relatively low concentrations, and when present at higher concentrations that exceed the solubility of the oxidizer, the oxidizer is solubilized and in solid form. In some embodiments, the oxidizer is completely solubilized (or substantially completely solubilized) in the composition. In such embodiments, an excess of solid oxidizer may be added, for example in the form of small pellets. In other embodiments, the oxidizer is only partially solubilized in the composition, in which case the solid oxidizer (e.g., in the form of solid small pellets) may be added just prior to detonation so that there is not enough time for the small pellets to substantially solubilize. The oxidizer may be in a liquid:solid ratio between 100:0 and 20:80, and any ratio in between. For example, the liquid:solid ratio may be between 100:0 and 70:30, between 80:20 and 60:40, or between 70:30 and 40:60, or between 5:50 and 30:70, or 100:0, 70:30, 60:40, 50:50, 45:55, 40:60; or 20:80.

It is also within the invention to have as further explosive components of the composition well known explosives including, for example, one or more of trinitrotoluene, nitroglycerin or pentaerythritol tetranitrate.

It will also be appreciated that these other oxidizing agents can be used to partially _{replace H2O2} in _{the H2O2} composition. Examples of such oxidizing agents are nitrates, perchlorates, sodium/potassium peroxide, etc.

Oxidizer:Fuel Ratio In one embodiment, the explosive composition may include a ratio of H ₂ O ₂ :one or more other oxidizers ranging between 100:1 and 30:70.

In one embodiment, the explosive composition may include a ratio of H ₂ O ₂ (or H ₂ O ₂ +one or more oxidizers):fuel ranging between 87:13 and 64:36.

In one embodiment, the explosive composition may include a ratio of H ₂ O ₂ (or H ₂ O ₂ +one or more oxidizers):fuel:water ranging between 60:20:20 and 72:24:4.

Energy deferments
The explosive compositions of the present invention may optionally include one or more energy retardants. Energy retardants include metal oxides such as aluminum oxide.

Energetic Diluents The explosive compositions of the present invention may optionally contain one or more energetic diluents.

In the context of the present invention, an energetic diluent is an inert material that makes a minimal contribution to the detonation process and can be used to replace a portion of the energetic material in the composition, thereby reducing the energy output of the _{H2O2 -} based explosive.

In some cases, these energy diluting agents can increase, decrease, or not change the density of the _H2O2 -based composition. In some cases, these _energy diluting agents can decrease the density of the _{H2O2 -} based composition without increasing the sensitivity.

Examples of these diluent materials are EPS (with particle size greater than 2 mm in diameter), granulated/shredded rubber (from tires), cottonseed, wood chips, husks, expanded popcorn, plastic beads, wool meal, pomace, peanut and oat husks, peanut husks, etc. US Patent No. 5,409,556 describes some examples of these energy reducing agents. In one embodiment, the energy reducing agent is selected from granulated/shredded tires, rubber, expanded rice kernels, expanded popcorn, expanded wheat, and combinations thereof. These materials can also be used in combination with sensitizers that provide more flexibility as long as attention is paid to the performance characteristics of the _{H2O2 -} based explosives (as shown in US Patent No. 5,470,407).

Therefore, another advantage of _H2O2 - _based explosives is that the performance characteristics of the explosives can be tailored to suit the characteristics of the blast site.

These variations in the general procedure will be apparent to those skilled in the art of preparing emulsion explosive compositions.

_{The H2O2} based compositions of hydrogels or emulsions produced according to the present invention contain energetic diluents at concentrations between 0-800% by volume (i.e., the volume can be increased by a factor of 8). As a result, the use of additives (sensitizers and energetic diluents) provides better control of density, VOD and energy delivery of the land being blasted.

Thus, an additional advantage of H ₂ O ₂ based explosive is that it can be used in a density range between about 0.1 g/ml and about 1.4 g/ml (eg, between about 0.3 g/cm ³ and about 1.4 g/cm ³ ).

In one preferred embodiment, the H ₂ O ₂ based explosive composition of the present invention comprises the following components: H ₂ O ₂ :fuel:water in the range of 25%:5%:70% to 73%:11%:16%.

Density of the explosive composition Suitably the final density is controlled to approximately 0.3-1.4 g/ ^cm3 using a sensitizer. Suitably the composition is formulated to have a density of approximately 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, ¹ , 1.1, 1.2, 1.3 or 1.4 g/ ^cm3 . Suitably the composition is formulated to have a final density between approximately 0.3-0.4, 0.4-0.5, 0.5-0.6, 0.6-0.7, 0.7-0.8, 0.8-0.9, 0.9-1.0, 1.0-1.1, 1.1-1.2, 1.2-1.3 or 1.3-1.4 g/cm3. In some embodiments the density is controlled to a predetermined target value by selection of the ratio of the components of the composition. By balancing the concentrations of density reducing components, such as hollow microspheres, and components having a relatively high density, such as nitrate globules, the density is controlled to a predetermined target value.

pH of explosive composition
The pH of the emulsion explosive composition of the present invention is not strictly critical, but generally the pH is between 0 and 8, suitably the pH is between 1 and 6, and can be controlled by the appropriate addition of conventional additives, such as inorganic or organic acids and salts.

Viscosity of _H2O2 - _based compositions
The viscosity of _{H2O2 -} based compositions (hydrous gel or emulsion type) is discussed in terms of apparent viscosity. As used herein, the term "apparent viscosity" refers to a measure of viscosity using a Brookfield RVT viscometer at 50 revolutions per minute with a #7 spindle.

In the method of the present invention, it is preferred that the explosive composition of the water-in-oil emulsion explosive grains has an apparent viscosity of greater than 10 Pa*s (Pascal*second) prior to gas bubble entrainment. More preferably, the apparent viscosity is in the range of 10-50 Pa*s. A more preferred viscosity range for gas bubble entrainment by mechanical mixing is 10-35 Pa*s. The range of 10-25 Pa*s provides the most efficient entrainment of gas bubbles by mechanical mixing.

Preferably, the explosive composition of the present invention can be easily pumped.

Oxygen Balance of Explosive Compositions "Oxygen Balance" (OB) is a term used in the art to indicate the degree to which an explosive can be oxidized. An OB close to zero is preferred when formulating a mining explosive such that there are no excess reactants during the detonation process, and thus the expected products are nitrogen, water, and carbon dioxide. If the oxygen balance is far from zero, a portion of the reactant materials will not react, and instead the unreacted materials will absorb/quench the heat from the detonation reaction, resulting in an underpowered explosive. For example, some prior art compositions are not suitable for combustion because they are starved of fuel (hence the OB is too positive) and the composition cannot burn.

Suitably, the amount of fuel material in the explosive composition may be adjusted so that the composition has a final oxygen balance of between +10 and -10, for example between +5 and -5.

Preparation of the Composition According to a second aspect, the present invention provides a method for preparing an explosive composition according to the first aspect, comprising _{combining H2O2} , and a fuel, and one or more density stabilizers, and optionally one or more other oxidizers, and/or a sensitizer, and one or more density stabilizers.

The _{H2O2 -} based compositions of the present invention can be prepared by several methods.

In one preferred method of fabrication, _{H2O2 -} based hydrogel type compositions can be prepared by _{combining H2O2} with a density stabilizer, a water-miscible fuel, and a thickener until the thickener begins to increase the viscosity of the composition. Once the hydrogel is formed, a solid ingredient (fuel, energy dilution agent, etc.) is optionally mixed with the hydrogel. A sensitizer can be mixed with the hydrogel in an amount capable of sensitizing the hydrogel. Finally, the sensitizer can be mixed with an oxidizer component prior to mixing with the hydrogel.

In one preferred method of manufacture, _{H2O2 -} based emulsion compositions can be prepared by combining hydrogen peroxide with a density stabilizer, a water-immiscible organic phase, and a water-in-oil emulsifier at high speed to form a water-in-oil emulsion; then mixing until the emulsion is uniform. Once the emulsion is formed, a solid source (fuel, energy dilution agent, etc.) is optionally mixed with the hydrogel. A sensitizer can be mixed with the emulsion in an amount capable of sensitizing the hydrogel. Finally, a sensitizer can be mixed with an oxidizer component prior to mixing with the emulsion.

Preparation of Hydrogel H ₂ O ₂ -Based Explosive Compositions Hydrogel compositions produced according to the present invention preferably contain H ₂ O ₂ in a concentration between 10 and 64% by weight.

It will also be appreciated that other oxidizing agents may be combined with _H2O2 as discussed above. For example, nitrates, perchlorates, _amine nitrates, _sodium /potassium peroxide, etc. may be incorporated in combination with _H2O2 .

Those skilled in the art will appreciate that there are many options available for use as fuel. For example, the fuel may be a product of vegetable origin, such as sugar or molasses, alcohol, organic acid, ether, ester, urea, hexamine, etc. Alternatively, the fuel may be a product derived from a crude oil, such as diesel fuel, paraffin oil, or mineral oil, etc. Other fuels may be silicone oil, etc.

The second fuel may be a solid hydrocarbon such as coal and recycled plastic waste. The second fuel may also be a metal fuel, such as aluminum/silicon, or Gilsonite, finely divided coke or charcoal, carbon black, resin acids such as abietic acid, plant products such as starch, nut foods, grain foods, and wood pulp; or nitrogen compounds such as amides, amines, etc.

Preferably, the amount of these fuel materials in the formulation can be adjusted so that the _{H2O2 based} composition has an oxygen balance between 3 and -10, making the _{H2O2 based} composition easily pumpable. Preferred fuels are oil distillates, hydrocarbons such as diesel fuel, glycerin, sugar, syrup, alcohol, carbon, pulverized coal, wax, oils such as corn, cottonseed, olive, peanut, or fatty acid oils.

It will be appreciated that for the _{H2O2 -} based composition according to the present invention to be functional, it is important that the gas bubbles are distributed homogeneously throughout the composition. It is also important that once distributed throughout, the gas bubbles should remain homogeneous throughout the composition, i.e., with little or no segregation or settling, and that the density should be maintained or stabilized to increase sleep time. In accordance with the present invention, this can be achieved by formulating the explosive as a stable hydrogel and including a density stabilizer. The formation of hydrogel compositions is conventional in the art, and those skilled in the art are familiar with the various forms that can be produced. Typically, the formation of hydrogel compositions involves the use of a thickening agent that acts on the liquid oxidizer component of the composition. As used herein, the term "thickening agent" is intended to include gelling agents, crosslinking agents, and the like.

As discussed above, any conventional thickening agent can be used in the present invention. The thickening agent can be selected from natural gums such as guar gum, xanthan gum, sodium alginate, carboxymethylcellulose, methylcellulose, and the like. Synthetic thickening agents such as polyacrylamides can also be used. Inorganic thickening agents such as fumed silica, clays, and carbosils, or combinations thereof, can also be used.

A crosslinking agent can also be used in the present invention. The thickener and the crosslinking agent can be combined to improve the water resistance and mechanical strength of the _{H2O2 -} based explosive. Examples of crosslinking agents are those made from antimony, calcium, titanium, chromium, borate, and dichromate, etc.

A variety of additional ingredients well known to those skilled in the art may be used in the formulations of the present invention.

Preparation of Water-in-Oil _{H2O2 -} Based Explosive Compositions Water-in-oil explosive compositions made according to the present invention include hydrogen peroxide at a concentration between 10-85% by weight. It will also be appreciated that other oxidizers may be combined with _{the H2O2} , as discussed above. For example, nitrates, perchlorates, amine nitrates, sodium/potassium peroxide, etc. may also be incorporated in combination with _{the H2O2} .

The fuel may be any fuel, for example, diesel fuel, recycled oil distillates, and distillates such as diesel fuel. Alternatively, the fuel may be paraffinic, mineral, olefinic, naphthenic, animal, vegetable, fish, and silicone oils. Other types of fuels are benzene, toluene, xylene, asphaltic materials, etc.

The second fuel may be a solid hydrocarbon such as coal and recycled plastic waste. The second fuel may also be a metal fuel, such as aluminum/silicon, or Gilsonite, finely divided coke or charcoal, carbon black, resin acids such as abietic acid, plant products such as starch, nut foods, grain foods, and wood pulp; or nitrogen compounds such as amides, amines, etc.

Preferably, the amounts of these fuel materials in the formulation can be adjusted so that the _{H2O2 based} composition can have an oxygen balance of between 3 and -10, making the _{H2O2 based} composition easily pumpable.

With respect to sensitization, similar considerations apply to water-in-oil explosive compositions as to the hydrogel compositions discussed above; that is, the gas bubbles are preferably distributed homogeneously throughout the composition. In accordance with the present invention, this is accomplished by formulating the explosive as a stable water-in-oil emulsion. The formation of emulsified explosives is conventional in the art, and those skilled in the art are familiar with the various forms that can be produced. Typically, the formation of emulsified explosives involves the use of an emulsifier adapted to maintain the oxidizer dispersed throughout the continuous organic phase (fuel).

Emulsifiers commonly used in emulsion explosive compositions include sorbitan monooleate, sorbitan sesquioleate, polyisobutylene succinic anhydride (PIBSA) and its amino derivatives, PIB lactone and its amino derivatives, fatty acid salts, lecithin, etc.

Use of the composition According to a third aspect, the present invention provides the use of an explosive composition according to the first aspect, for example for digging and moving earth in mining operations.

According to a fourth aspect, the present invention provides the use _of one or more density stabilizers to improve the sleep time of an explosive composition comprising _H2O2 and a fuel in reactive or metallurgical grounds.

Further embodiments of the present invention According to an embodiment of the present invention, there is provided a method of preparing an explosive composition comprising combining hydrogen peroxide with a density stabilizer and a sensitizer comprising compressible material and/or gas bubbles. It will also be appreciated that the present invention relates to a method of preparing an explosive composition comprising combining hydrogen peroxide and one or more compounds which generate a sensitizer.

According to a further embodiment of the present invention there is provided the use of an explosive composition comprising hydrogen peroxide and a density stabilizer, and a sensitizer comprising compressible material and/or gas bubbles. It will be appreciated that the composition of the present invention may be used for many purposes, but in particular for digging and moving earth during mining operations.

According to yet a further embodiment, the present invention provides a delayed self-sensitization, enhanced sleep time, sensitized explosive composition comprising _H2O2 , compressible _material and/or gas bubbles, and a density stabilizer.

In some embodiments, the invention consists essentially of _H2O2 , fuel, density stabilizer, and sensitizer including compressible material and/or gas bubbles. In other embodiments, the _invention consists essentially of _H2O2 , density stabilizer, fuel, sensitizer including compressible material and _{/or gas bubbles, thickener, and/or crosslinker. In other embodiments, the invention consists essentially of H2O2 , fuel} , density stabilizer, sensitizer including compressible material and/or gas bubbles, fuel, surfactant/emulsifier, thickener, and/or crosslinker.

In one embodiment, the present invention provides an explosive composition comprising about 2 to about 25% by weight H ₂ O ₂ ; greater than 0 and up to about 90% by weight of one or more other oxidizers; and a density stabilizer.

In one embodiment, an explosive composition is provided that includes about 2 to about 25% by weight H ₂ O ₂ ; and greater than 0 and up to about 90% by weight of one or more other oxidizers; and about 15 to about 25% by weight of a fuel, preferably a sustainable fuel, and a density stabilizer.

According to a preferred embodiment, the present invention provides _an explosive composition comprising about 2 to about 25% by weight _H2O2 ; greater than 0 and up to about 90% by weight of one or more other oxidizers; a fuel phase; a thickener and/or crosslinker; a second fuel; a sensitizer, and a density stabilizer.

In some embodiments, the composition comprises about 5 to about 25% by weight H ₂ O _2. Preferably, the one or more other oxidizers are salts or acids selected from the group consisting of nitrates, perchlorates, peroxide salts, or nitric acid. For example, the one or more other oxidizers may be selected from the group consisting of nitrates, perchlorates, sodium peroxide, potassium peroxide, and optionally nitric acid. The perchlorates may be selected from ammonium perchlorate and sodium perchlorate. Preferably, the salts are selected from ammonium nitrate (AN), calcium nitrate (CN), calcium ammonium nitrate (CAN), sodium nitrate (SN), NH ₄ ClO ₄ , NaClO ₄ , Na ₂ O ₂ , K ₂ O ₂ , or mixtures thereof. For example, the nitrates may be selected from ammonium nitrate, calcium nitrate, and sodium nitrate. As a further example, the nitrates may be selected from calcium ammonium nitrate, calcium nitrate, and sodium nitrate. In one embodiment, the explosive composition does not include AN. The one or more other oxidizers in the explosive composition may be selected from calcium nitrate and sodium nitrate. Preferably, the explosive composition comprises 0.1-75% by weight of the one or more other oxidizers. In one embodiment, the explosive composition comprises 0.1-75% by weight of dissolved salt. In a preferred embodiment, at least a portion of at least one of the one or more other oxidizers is not completely dissolved in the explosive composition, but is present as a solid oxidizer, for example in the form of a powder or small pellets. In such an embodiment, the one or more other oxidizers present at least partially as a solid may be selected from the group consisting of AN, SN, CN, CAN, or mixtures thereof. The composition may comprise a solid nitric acid oxidizer, for example in an amount of 0.1-70% by weight. The composition may comprise water. The solid nitrate oxidizer may be selected from the group of AN, SN, CAN, or mixtures thereof.

In one embodiment,
from about 2% to about 85% by weight hydrogen peroxide; and
from about 2 to about 25% by weight of a fuel, preferably a sustainable fuel; and
* DTPMPA.Na.x from about 0.25 to about 5
An explosive composition is provided comprising:

According to a preferred embodiment, the present invention
* from about 2 to about 25% by weight hydrogen peroxide; and from greater than 0 up to about 90% by weight of one or more other oxidizing agents; or from about 2 to about 85% by weight hydrogen peroxide;
* about 0.25 to about 3% by weight of DTPMPA.Na.x;
* Fuel phase;
* thickening and/or crosslinking agents;
* a second fuel; and
* Providing an explosive composition including a sensitizer.

Preferably, the composition comprises 50% by weight or less of water, or 30% by weight or less of water, or 25% by weight or less of water. The explosive composition may further comprise one or more other components selected from the group consisting of a sensitizer, a fuel, a second fuel, water, a thickener, a crosslinking agent, an emulsifier, an energy diluent, and optionally other additives.

Preferably, the explosive composition includes a sensitizer. Preferably, the sensitizer includes a compressible material and/or gas bubbles or gas entrapped material. The gas bubbles are formed in situ and may consist of _N2 , _O2 , _CO2 , NO or _H2 bubbles or mixtures thereof. The gas entrapped material may be selected from glass microballoons, ceramic microballoons, plastic microballoons or EPS having a particle size of less than 2 mm. The explosive composition preferably has a density controlled by adding a sufficient amount of sensitizer to make the composition detonation sensitive. The density may be controlled to approximately 0.3-1.4 g/ ^cm3 or formulated to approximately 0.3-1.4 g/ ^cm3 .

The composition may comprise a fuel or may comprise a fuel and a second fuel. The fuel may be a water-soluble fuel. The water-soluble fuel may be selected from amine nitrates or urea or mixtures thereof. The explosive composition may comprise 0.1-30% by weight of the water-soluble fuel. The composition may comprise between 13-25% by weight of the fuel phase. Preferably, the fuel phase comprises one or more components selected from the group consisting of rubber, glycerin, ethylene glycol, propylene glycol, molasses, formamide or mixtures thereof. For example, the fuel phase may comprise one or more components selected from the group consisting of rubber, glycerin, ethylene glycol, propylene glycol, formamide or mixtures thereof. The composition may comprise a sustainable fuel. The sustainable fuel may be present in the composition in an amount of 15-25% by weight.

Preferably, the composition is a hydrogel composition, in which case the composition may include a thickening agent or a crosslinking agent. The composition may be a hydrogel composition comprising a thickening agent and a crosslinking agent. The thickening agent may be suspended in the fuel. The thickening agent may be selected from the group consisting of guar gum, xanthan gum, sodium alginate, polyacrylamide and polyvinyl alcohol. The composition may include a crosslinking agent selected from the group consisting of antimony salts, chromium salts, phosphoric acid or mixtures thereof. The fuel phase may include one or more water insoluble fuels selected from the group consisting of diesel fuel, oils, vegetable oils or mixtures thereof. Thus, the explosive composition may be formulated as an emulsion, in which case it may include an emulsifier. The emulsifier may be mixed in the fuel. The emulsifier may be selected from the group consisting of PIBSA-amine derivatives, SMO, lecithin or mixtures thereof.

Preferably, the composition is formulated to have an oxygen balance between +10 and -10, for example, the composition may have an oxygen balance between +5 and -5. The explosive composition may include 1-800% v/v of an energy reducer (i.e., diluent material). The energy diluent material may be selected from the group consisting of EPS, crumb rubber tires, popcorn, and plastic beads. The hydrogen peroxide, one or more other oxidizers, and thickener-containing fuel may be mixed until a high viscosity material is formed having a viscosity between 5 and 50 Pa*s. The composition may have a viscosity of 5 to 50 Pa*s.

Many advantages derive from the explosive compositions of the invention taught herein. For example, certain formulations of the compositions of the invention may be more convenient to prepare, more cost-effective, safer to manufacture and store compared to existing explosive compositions, and/or can be manufactured in large quantities to meet the demands of the mining industry. Safety and wider application are added by the use of density stabilizers that extend the sleep time. Thus, the present invention is a significant advance in the industry. The explosive compositions of the present invention utilize _H2O2 , _a sustainably produced material that has a relatively low carbon footprint compared to other types of oxidizers used in the industry. The compositions may also use sustainable fuels as opposed to current technologies used in the mining industry. To illustrate, current explosive compositions typically use low concentrations of fuels sourced from the petrochemical industry. In contrast, the explosive compositions of the invention disclosed herein can incorporate a relative amount of recycled fuel to commercially available or prior art explosive compositions. Thus, recycled fuels from the petrochemical industry are a significant advance in the industry. In addition, the use of recycled fuel in the composition means that the amount of oxidizer material in the formulation can be balanced without affecting the detonation properties.

The present invention is counter-intuitive to common knowledge in the industry. To explain, it is currently believed that it is impossible or very difficult to stabilize the density of compositions with relatively high concentrations of _{H2O2 .} However, surprisingly, the present invention provides the ability to enhance the density stability of compositions containing up to 42% by _weight of _H2O2 . This aspect of the present invention is a significant advancement in the industry. The present invention provides the ability to incorporate relatively large amounts of nitrate by producing a hydrogel or emulsion that already contains _H2O2 / _nitrate in the aqueous phase and further has a solid nitrate phase in the form of small globules. The use of a solid form of oxidizer allows some control over the density of the entire composition, which provides some control over the VOD, as discussed below.

The explosive compositions of the present invention may also be formulated into emulsion forms. It will also be appreciated that while the compositions of the present invention may produce small amounts of _NOx , in some forms of the present invention, they do not produce any _NOx .

The compositions of the present invention are intended to offer several advantages over the prior art, such as better stability over time than explosive compositions containing a higher percentage _{of H2O2} . This is advantageous in both safety, storage and application contexts. More specifically, the "sleep time" (i.e. the time it takes for the explosive to degrade in situ when in contact with rock, resulting in a decrease in its rate of detonation below the defined useful limit of such explosive compositions) is expected to be longer than explosives containing a higher _percentage of _H2O2 . By way of example, density stabilized _{H2O2 compositions} according to the present invention have been produced and found to have a longer sleep time, e.g., more than 24 hours or more, than compositions without density stabilizers that are competitive/compatible for application in commercial products. It is therefore believed that larger explosions are possible because there is a longer time (e.g., several days) that the explosive can be loaded into many holes before the first charge becomes unstable in the hole. Thus, more holes can be loaded before detonation.

Another advantage is that these compositions will detonate when density stabilizers are used. This is unexpected because of concerns that density stabilized compositions may not detonate. There is also a safety advantage contemplated when using density stabilized compositions.

The present invention relates to a sensitized peroxide-based explosive composition, preferably formulated as a hydrogel or a water-in-oil emulsion.

Numerous embodiments are described in this patent application and are presented for illustrative purposes only. The described embodiments are not intended to be limiting in any manner. The present invention is broadly applicable to numerous embodiments as will be readily apparent from the disclosure herein.

Table 1 below lists the components of the explosive systems discussed herein and provides typical ranges for each.

Table 2 below lists typical ingredients for each type of explosive technology:

The present invention can be used for various forms of explosives, so long as the principles of the invention described herein are of course observed. The present invention is further illustrated with reference to the following examples.

Example 1
Hydrogen peroxide/fuel based hydrogel formulations with a glycerin fuel phase were handcrafted with materials calculated to contain 0-3% DTMPMA.Na.X by weight (see Table 3 below).

DTMPMA.Na.X was first suspended in the oxidizer phase and then mixed with the fuel phase of the formulation. Plastic pots (approximately 58 mL) were used to store the gels (n=4) on a laboratory bench at room temperature (25-35°C). Formulation density versus DTMPMA.Na.X wt% was determined for the range 0-3 wt%. Density was measured over a period of 7 days and the change in density was calculated. The test was terminated when the gel structure was compromised by the formation of large gas bubbles.

Several samples were prepared according to Table 3 below:

The results are shown in Figures 1 and 2. Within 2 days, the 0 wt% DTMPMA.Na.X formulation degraded, but the test was continued until all of the gel had been observed to degrade.

Table 4 below shows density versus time (g.cm ^-3 ) (days) for explosive compositions having various levels of phosphonate.

Table 5 below shows density loss (% of initial) versus time for explosive compositions having various levels of phosphonate.

While the formulation without density stabilized hydrogen peroxide degraded within 48 hours, the density stabilized hydrogen peroxide composition exhibited a density loss of approximately 7 percent relative to the initial density during the same period. This is a considerable and surprising improvement. This improvement in sleep time means that more blast holes can be loaded during the planned blast period saving time and money, the detonation performance of the product is more reliable, and the product has improved safety due to the reduced likelihood of density loss.

Example 2
To evaluate the explosive capabilities and characteristics of density stabilized hydrogen peroxide compositions, detonation performance analysis was performed in open field tests on a formulation of 81.35% hydrogen peroxide (50% by weight), 12.65% glycerin fuel, 3% xanthan gum, and 3% DTPMPA.Na.x by weight incorporating various weight percentages of GMB (3M™ K15 Glass Bubbles) for required density (see Table 4 below).

Table 6 below shows the results of detonation testing of explosive compositions prepared according to the present invention.

Three samples of the explosive composition were prepared.

The results are shown in Figure 3.

As can be seen from these examples, the density loss and instability of the hydrogen peroxide-based explosives decreased with the addition of phosphonate, increasing the sleep time of the formulation. The use of hydrogen peroxide/fuel-based explosives prepared with the addition of phosphonate results in a substantial improvement in hydrogen peroxide/fuel-based explosives in the art. Importantly, the addition of the density stabilizers described herein does not adversely affect the detonation performance of the explosive composition.

Detonation Testing Selected compositions were tested to measure detonation. A 47 mm diameter, clear, high density (150 μm) polyethylene layflat tube, 1000 mm long and sealed at one end, was used as the gel. 25 g of Pentex D Booster was used to initiate the detonation.

Using a Time Domain Reflectometry (TRD) based VOD instrument, the VOD was measured in duplicate and featured sample velocities of less than 4uS with a nominal resolution of 90ps. The VOD data indicates acceptable detonation performance for mining applications.

Example 3
Stabilized hydrogen peroxide/fuel-based hydrogel formulations with a glycerin fuel phase were handcrafted with materials calculated to contain 0-2% phytic acid (PA) by weight. The PA was first suspended in the oxidizer phase and then mixed with the fuel phase of the formulation (3% xanthan gum). Plastic pots (approximately 58 mL) were used to store the gels (n=4) on a laboratory bench at room temperature (20-25°C). Product density versus PA by weight was established for the range 0-5% PA. Density was measured and density change calculated over a period of 13 days. Testing was terminated when the gel structure was compromised by the generation of large gas bubbles. PA from 3-5% by weight degraded within 5 days, but testing was continued until all gel degradation was observed.

Over the course of 10 and 13 days for each of the two tests, all gels were observed to decrease in density. Initial gel densities were all approximately 1.22 g.cm ^-3 . As the weight percent PA increased, an associated increase in gel density was observed (Figures 4 and 5). Gels containing 3-5 wt% PA degraded within 5 days. At approximately 7 days, the degradation rate of the no PA control appeared to change, which may be an indicator of HP degradation approaching completion. Although 0.25 wt% PA showed the least density loss over time (Figures 6 and 7), no statistically significant loss was measured between the no PA and 0.25 wt% PA gels (p-value = 0.19) over the course of 13 days. Over the measurement time, the standard deviation of repeated individual pot measurements did not exceed 0.02 mL.

Formulations containing PA at concentrations between 0.25 and 0.75% by weight showed increased gel stability over 13 days. However, at concentrations above about 0.75%, PA underwent accelerated degradation. After 13 days of room temperature bench storage, all gels, including those containing PA, lost at least 18% gel density when compared to the initial density.

The skilled reader will understand that the present invention includes the embodiments and features disclosed herein, and all combinations and/or permutations of the disclosed embodiments and features.

Although the present invention has been described with reference to specific embodiments, it will be appreciated by those skilled in the art that the present invention may be embodied in many other forms. In particular, features of any one of the various described embodiments may be provided in any combination with the other described embodiments.

Claims (34)

_{H2O2 ;}
fuel ;
0.01 % to 10 % by weight of one or more density stabilizers ; and
Sensitizer
An explosive composition comprising:
the density stabilizer comprises a phosphonate;
An explosive composition formulated as an emulsion or hydrogel . _2. The explosive composition according to claim 1, wherein _H2O2 is 2 % to 85% by mass. 3. An explosive composition according to claim 1 or claim 2, wherein the one or more density stabilizers are in an amount of 1 to 5 % by weight. 3. An explosive composition according to claim 1 or claim 2, wherein the one or more density stabilizers are in an amount of 1 to 3% by weight. 5. An explosive composition according to any one of claims 1 to 4, wherein the phosphonate is phytic acid or diethylenetriaminepentamethylenephosphonic acid sodium salt. 6. An explosive composition according to any one of claims 1 to 5 , wherein the density stabilizer maintains the density of the explosive composition within +/- 10% of its initial density. 7. The explosive composition of claim 6 , wherein the density is maintained for a period of 10 days or less. 8. The explosive composition of claim 6 or claim 7 , wherein the density stabilizer maintains the velocity of detonation (VOD) within +/- 10% of its initial VOD. 9. The explosive composition of claim 8 , wherein the VOD is maintained for a period of 14 days or less. 10. An explosive composition according to any one of claims 1 to 9 , further comprising water . 11. The explosive composition according to claim 1, further comprising up to 50% by mass of water. 12. The explosive composition according to claim 1, further comprising up to 25% by mass of water. 13. The explosive composition according to any one of claims 1 to 12, further comprising one or more other components selected from the group consisting of one or more other oxidizers , a second fuel, a thickener, a crosslinker , an emulsifier and an energetic diluent. 14. An explosive composition according to any one of claims 1 to 13 , wherein the sensitizer comprises a compressible material and/or gas bubbles. 15. The explosive composition of claim 14 , wherein the gas bubbles are formed in situ and consist of _N2 , _O2 , _CO2 , _H2 bubbles or mixtures thereof. 16. The explosive composition according to claim 14 or 15 , wherein the compressible material is a gas-trapping material selected from glass microballoons, ceramic microballoons, plastic microballoons or expanded polystyrene (EPS) having a particle size of less than 2 mm. 17. An explosive composition according to any one of claims 1 to 16 , wherein a sensitizer is added in an amount sufficient to render the explosive composition sensitive to detonation. The explosive composition according to claim 17 , wherein the density of the explosive composition is controlled to about 0.3 to 1.4 g/cm ³ . 19. The explosive composition according to any one of claims 13 to 18 , wherein the energetic diluent is selected from the group consisting of expanded polystyrene (EPS) , crumb rubber tires, popcorn and plastic beads. 20. An explosive composition according to any one of claims 13 to 19 , wherein the one or more other oxidizers are present in an amount of 0.1 to 75% by weight . 21. An explosive composition according to any one of claims 13 to _{20 ,} wherein the one or more other oxidizers are selected from the group consisting of nitrates, perchlorates , sodium peroxide ( _Na2O2 ) , _potassium peroxide ( _K2O2 ) , and optionally nitric acid (HNO3 ) . 22. The explosive composition of claim 21, wherein the oxidizer is selected from ammonium nitrate (AN), calcium nitrate (CN), sodium nitrate (SN), calcium ammonium nitrate (CAN), ammonium perchlorate (NH4ClO4 ₎ , _sodium perchlorate (NaClO4 ) _, sodium peroxide ( Na2O2 _{) ,} potassium _peroxide ( _K2O2 ) or mixtures thereof. _22. The explosive composition of claim 21, wherein the perchlorate is selected from ammonium perchlorate (NH4ClO4 ₎ and sodium perchlorate (NaClO4 ₎ . 24. An explosive composition according to any one of claims 13 to 23 , wherein the thickening agent is selected from the group consisting of guar gum, xanthan gum, sodium alginate, polyacrylamide, polyvinyl alcohol , or mixtures thereof . 25. An explosive composition according to any one of claims 13 to 24 , wherein the cross-linking agent is selected from the group consisting of antimony salts, chromium salts, phosphoric acid or mixtures thereof. 26. An explosive composition according to any one of claims 13 to 25 , wherein the emulsifier is selected from the group consisting of polyisobutylene succinic anhydride (PIBSA) based derivatives, sorbitan monooleate (SMO), lecithin or mixtures thereof. The explosive composition according to any one of claims 1 to 26, comprising 2 to 25 mass % fuel. The explosive composition of claim 27, wherein the fuel comprises one or more water-insoluble fuels selected from the group consisting of diesel fuel, oil, paraffin oil, naphthenic oil, vegetable oil, or mixtures thereof. The explosive composition according to claim 27 or 28, comprising a water-soluble fuel selected from glycerin, amine nitrates, urea, or mixtures thereof. The explosive composition according to any one of claims 1 to 29, formulated to have an oxygen balance between +10 and -10. The explosive composition according to any one of claims 1 to 30, which is formulated to have a viscosity of 5 to 50 Pa*s. 32. A method for preparing an explosive composition according to any one of claims ₁ to 31, comprising combining _H2O2 , a fuel, and 0.01 % to 10 % by weight of one or more density stabilizers, sensitizers, and optionally one or more other oxidizers ,
the density stabilizer comprises a phosphonate;
The method, wherein the composition is formulated as an emulsion or a hydrogel . Use of the explosive composition according to any one of claims 1 to 31 for digging and moving land. _1. Use of an explosive composition in reactive or metallic ground to improve sleep time, said explosive composition comprising _H2O2 , a fuel, a sensitizer, and 0.01 % to 10 % by weight of one or more density stabilizers;
the density stabilizer comprises a phosphonate;
The composition is formulated as an emulsion or a hydrogel .