JP6961143B2 - Column reinforcement method for column-type coal mining method - Google Patents

Description

The present invention belongs to the technical field of mining, and specifically relates to a method for reinforcing a column for a column-type coal mining method.

Mining resources are non-renewable resources, and achieving the safety, high efficiency and sufficient mining of mining resources is the goal pursued by mining engineering engineers and managers. Assuming the ore is stable, the columnar coal mining method is the most efficient mining method for mining horizontal or gently sloping ore bodies, and it is generally necessary to leave various types of ore columns in the mining process. As the mining work surface advances, the construction environment of the mine is constantly changing, the mining traces become larger and larger, the stability problem of the mine becomes more prominent, and it is used for safe production of mines and drilling plans for deep ore bodies. Direct effect. The ore column is an important component that determines the stability of the mine, supports the mine site, maintains the stability of the mine's top and host rock, and not only ensures safe production, but is also stable. It has a very large potential effect on improving the ore mining rate of the pillars. Instability of the ore column may cause the collapse of the roof and host rock, which may lead to a large-scale disaster. Increases, mining loss and poor mineralization rate increase, air is compressed and formed into an impact air flow, which threatens the safety of workers. Therefore, in order to improve the overallity, stability and self-strength of the ore column, maintain the stability of the mine top, and realize safe mining, the ore column must be reinforced during the mining process. .. Currently, the main methods for reinforcing ore columns are anchor rod reinforcement, high water content solidifying wall reinforcement, grout reinforcement, filling reinforcement, and the like.

Chinese Patent Application Publication No. 107572949

The present invention provides a grout slurry having high stability, fluidity and stone formation rate and adjustable gelation time, and the resulting stone body has high crushing strength and durability and excellent waterproof impermeableness. To provide an anchor rod for injecting the grout slurry for an ore column having a large anchor fixing force, to provide a slurry injection method using a slurry injection anchor rod for an ore column, and to provide an anchor rod. It organically bonds the grout slurry support action, has the dual action of anchor rod support and grout slurry reinforcement, effectively improves the bedrock structure and receiving state of the ore column, reduces stress concentration, and of the ore column. It is an object of the present invention to provide a method for reinforcing a ore column for a column-type coal extraction method, which can improve the load bearing capacity.

A grout slurry containing A liquid and B liquid, wherein the A liquid contains 45 to 63 wt% of Portland cement, 25 to 46 wt% of fly ash, 3 to 7 wt% of slag, and aluminum dihydrogen phosphate. It contains 0 to 2.0 wt% and 2.0 to 3.0 wt% of sodium hexametaphosphate, has a water-cement ratio of 0.7 to 1.1, and the liquid B is 15 to 25 wt% of water glass. Contains 5 to 28 wt% fly ash and water.

Grout slurries containing Portland cement, flying ash, and slag are known to cause sedimentation and affect construction after being left for a long time, so they act as a suspension in the grout slurry. Substances that can be added should be added to reduce particle sedimentation, reduce slurry water separation and meet construction needs. In this embodiment, aluminum dihydrogen phosphate and sodium hexametaphosphate are added to the grout slurry, and aluminum dihydrogen phosphate and sodium hexametaphosphate are added to the slurry to Portland cement in the instep liquid. It can suspend cement, flying ash and slag, reduce particle sedimentation and slurry water separation rate, guarantee slurry stability, reduce slurry viscosity and increase fluidity, while reacting with Portland cement. Then, calcium phosphate, which is a sparingly soluble substance, is generated on the surface, and the rate at which Portland cement hydrates to produce calcium hydroxide can be slowed down, and the reaction between Portland cement and water glass can be slowed down and condensed. It can act as a delay and can also react with water glass to produce an aluminosilicate polymer with a network structure, which effectively adheres each component in the slurry to the slurry. It is possible to improve the stone formation rate and the crushing strength of the stone body.

The grout slurry disclosed in the present embodiment has good stability, fluidity and stone formation rate, and the grout slurry has flying ash in the liquid B and aluminum dihydrogen phosphate and hexametaphosphate in the liquid A. The gelation time of the slurry can be adjusted by adjusting the amount of sodium added, the gelation time of the slurry can be adjusted from several tens of seconds to several tens of minutes, and the volume ratio of the two liquids is 1: 1. The grout slurry has a good water-retaining ability, does not have a volume shrinkage phenomenon after gelling and solidifying, and has a strong binding force to the slurry injection target medium. The resulting stone body has high crushing strength and durability, is excellent in waterproof impermeableness, and greatly improves the reinforcing effect of the slurry injection anchor rod.

In one embodiment of the present invention, the amount of unburned carbon in fly ash is 10 to 15 wt%, and the particle size D50 is 15 to 23 μm. D50 is a particle size in which the integrated value from the small diameter side of fly ash is 50%. The amount of coarse powder and porous unburned carbon in the fly ash is small, has almost no effect on the fluidity of the slurry, and is advantageous for the strength of the calculus.

In one embodiment of the present invention, the volume ratio of the liquid A and the liquid B is 1: 1.

Slurry injection anchor rod for ore columns with large anchor fixing force, in which the grout slurry is injected.

In one embodiment of the present invention, the slurry injection anchor rod includes a rod body, a slurry discharge hole, a drill, a tray, an anti-friction gasket, and a nut, and the tip of the outer rod body has the above-mentioned slurry injection anchor rod. A slurry discharge hole is provided, an inner rod body is connected to the inside of the outer rod body via a pin, the slurry discharge hole is provided inside the rod body, and the slurry injection anchor rod is provided. , Tray, anti-friction gasket, nut , fixed in the hole. The drill design can combine the drilling work and the anchor rod mounting work into one work, shortening the anchor rod mounting time, improving the anchor rod mounting efficiency, and causing severe hole collapse. It is possible to improve the pore formation rate by avoiding the generation of waste holes due to Filling to close the pores of the columnar rock layer, improve the physical mechanical properties of the columnar rock layer, suppress the delamination and sliding of the columnar rock layer, and improve the integrity and self-stability of the columnar rock layer. On the other hand, it can be filled in the gap between the ore column and the rod body to increase the relative stability between the ore column and the rod body, and effectively improve the supporting effect of the slurry injection anchor rod. be able to. In short, the design of the slurry discharge holes can further improve the robustness and self-loading capacity of the ore column.

Slurry injection for ore column This is a slurry injection method using an anchor rod. A step of making holes in the ore column at 1/4 to 3/4 of the predetermined drilling length and cleaning the holes, and a hole in the drill end of the rod body. Insert it inside, attach the other end of the rod body to the drilling machine, make a hole to the predetermined drilling length, insert the slurry injection tube into the rod body, and calculate the required slurry injection amount from the predetermined anchor length. The slurry injection pump is operated to inject the slurry into the rod through the slurry injection pipe, and the slurry injection amount is controlled by the measuring device on the slurry injection pump, and the slurry injection pipe is gradually pulled out while injecting the slurry. While filling the gap of the slurry injection pipe with the slurry, the slurry is discharged from the rod body through the slurry discharge hole and filled in the gap between the ore column rock layer and between the inside of the ore column and the rod body, and the liquid level at the hole opening is raised. When the slurry injection is stopped, the slurry injection is stopped, and the slurry flows out from the rod body through the slurry discharge hole, so that it permeates between the columnar rock layers, fills with cement, closes the voids of the columnar rock layer, and blocks the columnar rock layer. Improves the physical mechanical properties of the slurry, suppresses slurry separation and sliding, improves the integrity and self-stability of the slurry, while filling the gap between the slurry and the rod body. , Strengthens the bond strength between the ore column and the rod body, and effectively improves the supporting effect of the slurry injection anchor rod. Then, the rod body and the slurry discharge hole hole cooperate with each other to increase the flow area inside the rod body, the resistance to the flow of the slurry is low, it is advantageous for the diffusion of the slurry, and the high pressure injection becomes possible. , The step of attaching the tray, the anti-friction gasket, and the nut to the exposed part of the rod body in order, and the step of preloading the rod body using a tensile tester after the slurry has solidified.

It is a column reinforcement method for the column-type coal mining method. It organically bonds the supporting action of the anchor rod and the grout slurry, has the dual action of supporting the anchor rod and reinforcing the grout slurry, and has an effect on the bedrock structure of the ore column. It is possible to improve the quality of the ore, guarantee the integrity of the ore, improve the receiving condition of the ore, reduce the stress concentration, and improve the load bearing capacity of the ore. Anchor rod work is performed on the ore column by adopting the above-mentioned ore column reinforcement method.

In one embodiment of the present invention, the column reinforcement method for the column bunch type coal mining method further includes spraying concrete to the outside of the column. Preferably, the concrete layer thickness is 7-12 cm.

In one embodiment of the present invention, the concrete is foam concrete, preferably the dry apparent density of the foam concrete is 1100 to 1500 kg / m ³ .

More preferably, the concrete contains continuous fibers. The continuous fiber further improves the bending strength of the concrete and the bonding force between the concrete and the ore column, and finally enhances the reinforcing effect on the ore column.

The grout slurry of the present invention has good stability, fluidity and calculus rate as compared with the prior art, the gelation time is adjustable, and the two liquids are injected in a 1: 1 volume ratio. The injection is easy to handle and

The calculus body made of grout slurry of the present invention has high crushing strength and durability, is excellent in waterproof impermeableness, improves the anchor fixing force of the slurry injection anchor rod, and greatly improves the reinforcing effect of the slurry injection anchor rod. Realized to do,

The slurry injection anchor rod of the present invention can improve the integrity and self-stability of the column rock layer, and can improve the fastness and self-load bearing capacity of the column.

The present invention organically bonds the supporting action of the anchor rod and the grout slurry, has the dual action of supporting the anchor rod and reinforcing the grout slurry, effectively improves the bedrock structure and the receiving state of the ore column, and stress concentration. Can be reduced and the load bearing capacity of the ore column can be improved.

The present invention employs the above technical solutions to provide a column reinforcement method for a column-bundle coal mining method, which makes up for the lack of prior art, is rational in design, and is easy to operate.

It is the schematic of the slurry injection anchor rod of this invention. It is the schematic of the slurry injection process of this invention. It is a schematic diagram of the ore column reinforcement of this invention. It is the strength of the grout slurry stone body in Test Example 1 of the present invention. It is the drying shrinkage rate of the grout slurry calculus body in Test Example 1 of this invention. It is the reaction concentration of chloride ion in the grout slurry calculus body in Test Example 1 of this invention. It is the corrosion resistance coefficient in the erosion solution of the grout slurry calculus body in Test Example 1 of this invention. It is the 28d crushing strength of the foamed concrete in Test Example 2 of the present invention. It is a rock integrity index in Test Example 3 of the present invention.

The present invention is capable of various modifications and modifications, the particular embodiments of which are illustrated in detail below, exemplary. However, it is not intended to limit the invention to the disclosed special forms, and conversely, the invention includes any modifications, equalities and alternatives that are consistent with the ideas of the invention as defined by the claims. include.

These examples are for explaining the present invention more concretely, and based on the gist of the present invention, the scope of the present invention is not limited to these examples, which are those skilled in the art. It is self-evident to.

One embodiment of the present invention provides a grout slurry, which comprises an instep solution and a B solution, wherein the instep solution contains 45 to 63 wt% of Portland cement, 25 to 46 wt% of fly ash, and 3 to 7 wt of slag. %, 1.0 to 2.0 wt% of aluminum dihydrogen phosphate, and 2.0 to 3.0 wt% of sodium hexametaphosphate, and the water-cement ratio is 0.7 to 1.1. The liquid contains 15-25 wt% water glass, 5-28 wt% fly ash and water.

The slag itself is a glass structural substance with potential activity, the glassy slag does not have the ability to cure by hydration alone, and the slag contains a large amount of CaO as an industrial waste having latent hydraulicity and is pure. In water, the hydration reaction is slow and does not hydrate, but its activity is excited by the exciting action of a basic substance such as _{NaOH or Ca (OH) 2, and the hydration reaction can be promoted.} Flying ash has a pozolan effect and a microaggregate effect, does not have hydration hardening ability by itself, and does not easily act on water by itself, but when an isobasic substance is present in the system, it is basically excited. Under the action of the agent, the vitreous substance in the flying ash is gradually disassembled, the silicate ion and the aluminate ion are dissolved, and the hydration reaction is carried out with the ion in the solution to produce a gel-like aluminosilicate. , Durability after solidification of slurry is improved.

Grout slurries containing Portland cement, flying ash, and slag are known to cause sedimentation and affect construction after being left for a long time, so they act as a suspension in the grout slurry. Substances that can be added should be added to reduce particle sedimentation, reduce slurry water separation and meet construction needs. In this embodiment, aluminum dihydrogen phosphate and sodium hexametaphosphate are added to the grout slurry, and aluminum dihydrogen phosphate and sodium hexametaphosphate are added to the slurry to Portland cement in the instep liquid. It can suspend cement, flying ash and slag, reduce particle sedimentation and slurry water separation rate, guarantee slurry stability, reduce slurry viscosity and increase fluidity, while reacting with Portland cement. Then, calcium phosphate, which is a sparingly soluble substance, is generated on the surface, and the rate at which Portland cement hydrates to produce calcium hydroxide can be slowed down, and the reaction between Portland cement and water glass can be slowed down and condensed. It can act as a delay and can also react with water glass to produce an aluminosilicate polymer with a network structure, which effectively adheres each component in the slurry to the slurry. It is possible to improve the stone formation rate and the crushing strength of the stone body.

The grout slurry disclosed in the present embodiment has good stability, fluidity and stone formation rate, and the grout slurry has flying ash in the liquid B and aluminum dihydrogen phosphate and hexametaphosphate in the liquid A. The gelation time of the slurry can be adjusted by adjusting the amount of sodium added, the gelation time of the slurry can be adjusted from several tens of seconds to several tens of minutes, and the volume ratio of the two liquids is 1: 1. The grout slurry has a good water-retaining ability, does not have a volume shrinkage phenomenon after gelling and solidifying, and has a strong binding force to the slurry injection target medium. The resulting stone body has high crushing strength and durability, is excellent in waterproof impermeableness, and greatly improves the reinforcing effect of the slurry injection anchor rod. In addition, the instep liquid further contains slag, and chloride ions in the gypsum slurry are mainly present in the compound form, the amount of free state is low, the probability of chloride ion erosion destruction is small, and it is early in the sulfate environment. A protective layer is formed on the surface of the calculus body. Is prevented from forming stone cracks, and material durability is improved. Preferably, the instep liquid contains 1-6 wt% of slag.

In one embodiment of the invention, the pH of the grout slurry is greater than 12, satisfying the pH requirements of the alkali-activated fly ash and the slag.

In one embodiment of the present invention, the amount of unburned carbon in fly ash is 10 to 15 wt%, and the particle size D50 is 15 to 23 μm. The amount of coarse powder and porous unburned carbon in the fly ash is small, has almost no effect on the fluidity of the slurry, and is advantageous for the strength of the calculus.

In one embodiment of the invention, the concentration of water glass is 25-35 Baume. Water glass with a Baume scale in this range does not have a large effect on the gelation time of the slurry, but can interact with fly ash and other components in the instep liquid to improve the crushing strength of the calculus. ..

In one embodiment of the present invention, the volume ratio of the liquid A and the liquid B is 1: 1.

In one embodiment of the present invention, the method for preparing a grout slurry is to uniformly put Portland cement, flying ash, slag, aluminum dihydrogen phosphate, sodium hexametaphosphate, and water in a cement mortar mixer. The step of forming the instep liquid by stirring and mixing with Includes a step of placing in and stirring uniformly, and finally obtaining a grout slurry.

One embodiment of the present invention further provides a slurry injection anchor rod for ore columns and injects the grout slurry. Increase the anchor fixing force of the slurry injection anchor rod.

In one embodiment of the present invention, as shown in FIG. 1, a schematic diagram of the slurry injection anchor rod includes a rod body, a slurry discharge hole, a drill, a tray, and an anti-friction gasket. , The inner rod body is connected to the inside of the outer rod body via a pin, and the inside of the rod body is provided with the slurry discharge hole at the tip of the outer rod body. The slurry discharge hole is provided, and the slurry injection anchor rod is fixed to the hole by a tray, an anti-friction gasket, and a nut. The drill design can combine the drilling work and the anchor rod mounting work into one work, shortening the anchor rod mounting time, improving the anchor rod mounting efficiency, and causing severe hole collapse. It is possible to improve the pore formation rate by avoiding the generation of waste holes due to Filling to close the pores of the columnar rock layer, improve the physical mechanical properties of the columnar rock layer, suppress the delamination and sliding of the columnar rock layer, and improve the integrity and self-stability of the columnar rock layer. On the other hand, it can be filled in the gap between the ore column and the rod body to increase the relative stability between the ore column and the rod body, and effectively improve the supporting effect of the slurry injection anchor rod. be able to. In short, the design of the slurry discharge holes can further improve the robustness and self-loading capacity of the ore column.

One embodiment of the present invention further provides a slurry injection method using a slurry injection anchor rod for an ore column, and the slurry injection process is as shown in FIG. 2, which is 1/4 to 3 of a predetermined drilling length in the ore column. / 4 holes and cleaning steps, and the drill end of the rod body is inserted into the hole, the other end of the rod body is attached to the drilling machine, the hole is drilled to the specified drilling length, and the slurry is inside the rod body. The required slurry injection amount is calculated from the step of inserting the injection pipe and the predetermined anchor length, the slurry injection pump is operated to inject the slurry into the rod through the slurry injection pipe, and the slurry injection amount is on the slurry injection pump. By gradually pulling out the slurry injection pipe while injecting the slurry, the gap of the slurry injection pipe is filled with the slurry, and the slurry is discharged from the rod body through the slurry discharge hole, and between the ore rock layers. And the gap between the inside of the ore column and the rod body is filled, and when the liquid level at the hole mouth stabilizes, the slurry injection is stopped, and the slurry flows out from the rod body through the slurry discharge hole, so that the ore column rock layer Penetrate in between, fill with cement to block voids in the slurry layer, improve the physical mechanical properties of the slurry layer, suppress slurry and sliding of the slurry layer, completeness of the slurry layer While improving self-stability, it fills the gap between the ore column and the rod body to strengthen the bond strength between the ore column and the rod body, effectively improving the supporting effect of the slurry injection anchor rod. .. Then, the rod body and the slurry discharge hole hole cooperate with each other to increase the flow area inside the rod body, the resistance to the flow of the slurry is low, it is advantageous for the diffusion of the slurry, and the high pressure injection becomes possible. , The step of attaching the tray, the anti-friction gasket, and the nut to the exposed part of the rod body in order, and the step of preloading the rod body using a tensile tester after the slurry has solidified.

In one embodiment of the invention, the injection pressure is 2.3-6.5 MPa.

In one embodiment of the invention, the injection rate is 15-25 L / min.

In one embodiment of the present invention, at least one steel penetrating both ends of the rod body through the rod body in order to significantly increase the strength of the anchor rod and further enhance the effect of reinforcing the anchor rod and reinforcing the ore column. A core wire may be provided.

One embodiment of the present invention further provides a column reinforcement method for a column-bundle coal mining method, and employs the slurry injection method for an ore column to perform anchor rod work.

This embodiment organically bonds the supporting action of the anchor rod and the grout slurry, has the dual action of supporting the anchor rod and reinforcing the grout slurry, effectively improves the bedrock structure of the ore column, and improves the completeness of the ore column. It can be guaranteed, the receiving condition of the ore column can be improved, the stress concentration can be reduced, and the load bearing capacity of the ore column can be improved. Preferably, the ore column is reinforced by dividing it into multiple parts, the spacing and row pitch of the anchor rods are both 0.8 to 1.5 m, the length of the anchor rods is 1.5 to 2.5 m, and the ore body is mined. It is possible to thoroughly solve the safety problems of the coal mine delivery work in the site.

In one embodiment of the present invention, the column reinforcement method for the column bunch type coal mining method further includes spraying concrete to the outside of the column. Preferably, the concrete layer thickness is 7-12 cm.

In one embodiment of the present invention, the concrete is foam concrete, preferably the dry apparent density of the foam concrete is 1100 to 1500 kg / m ³ . Foamed concrete can adhere to the roof host rock, and the effects of reinforcement and ore column reinforcement can be further enhanced. In addition, foamed concrete has a low elastic modulus, can effectively absorb the energy released by vibration during mining, and has a good damping effect. In addition, the weight reduction of foamed concrete can reduce the foundation stress and reduce the overall construction cost. In addition, a large number of fine holes in the foamed concrete can satisfactorily block absorbed sound waves and reduce noise in the mining area.

Preferably, the foamed concrete contains 35 to 42 wt% of Portland cement, 45 to 60 wt% of recycled waste concrete, 25 to 28 wt% of water, 12 to 16 wt% of fine sand, 2 to 5 wt% of aluminum metaphosphate, and 0. It contains 05 to 1 wt%, 0.8 to 1.18 wt% of hydrogen peroxide solution, 0.05 to 0.12 wt% of foam stabilizer, and 1 to 2 wt% of quick-setting admixture. The foamed concrete has more minute pores, has a relatively low dry density and a high porosity, has a particularly high sound absorption coefficient and a noise reduction coefficient, has a high noise reduction effect of the foamed concrete, and is mined. It provides a good environment and the strength of foamed concrete is high.

In order to further increase the strength of the concrete and the bonding force between the concrete and the ore column, it is finally preferable to include continuous fibers in the concrete in order to reinforce the reinforcing effect on the ore column. More preferably, the continuous fiber is one or more of aramid fiber, basalt fiber, carbon fiber or glass fiber. When the amount of continuous fibers in the concrete is 0.5 to 1.8 wt%, the porosity of the foamed concrete is increased by 3 to 6 wt%, the crushing strength is increased by at least 12 wt%, and the noise reduction effect of the concrete is improved. Can be enhanced.

Preferably, anchor rod driving, wire mesh insertion, and concrete spraying work are performed on the ore column. The wire mesh is preferably HPB235 grade reinforcing bar, has a specification of Φ6 to 10 mm, a mesh density of 25 cm × 25 cm, and a lap joint of 100 mm or more. Anchor rods and wire mesh can be used to simultaneously provide concrete spray support to reinforce the ore column and ensure the integrity of the ore column, with no apparent destruction of the ore column after reinforcement as the mining work progresses. The completeness of the pillars ensures normal and safe mining of the mine.

The present invention will be further described below by way of examples. However, the above-described embodiment is presented as an example, and is not intended to limit the scope of the invention.

Example 1:

It is a grout slurry containing A liquid having a volume ratio of 1: 1 and B liquid, and the A liquid is 42.5 grade Portland cement 52 wt%, fly ash 33 wt%, slag 4.5 wt%, phosphorus. It contains 1.2 wt% of aluminum dihydrogen acid and 2.4 wt% of sodium hexametaphosphate, has a water-cement ratio of 0.8, and shows the chemical components of the cement, fly ash and slag in Table 1 and the particle size. Shown in 2.

The liquid B contains 22 wt% of water glass, 16 wt% of fly ash and water, the concentration of the water glass is 25 to 35 Baume degree, and the amount of unburned carbon in the fly ash is 12.3 wt%. The particle size D50 is 22.4 μm.

Table 1: Chemical composition of raw materials (wt%)

Table 2: Particle size distribution of raw materials (μm)

The grout slurry is produced by uniformly stirring and mixing 42.5 grade Portoland cement, flying ash, slag, aluminum dihydrogen phosphate, sodium hexametaphosphate and water with a cement mortar stirrer to mix the instep liquid. After preparing the water glass solution with the required degree of broom, add flying ash and stir evenly to form the B solution, and add the B solution to the instep solution at a volume ratio of 1: 1. Includes a step of uniformly stirring and finally preparing a grout slurry.

Example 2:

It is a grout slurry containing A liquid having a volume ratio of 1: 1 and B liquid, and the A liquid is 42.5 grade Portland cement 52 wt%, fly ash 33 wt%, slag 4.5 wt%, phosphorus. It contains 1.2 wt% of aluminum dihydrogen acid and 2.0 wt% of sodium hexametaphosphate, has a water-cement ratio of 0.8, and the chemical components of the cement and fly ash are shown in Table 1 and the particle size is shown in Table 2. ..

The liquid B contains 22 wt% of water glass, 28 wt% of fly ash and water, the concentration of the water glass is 35 Baume degree, the amount of unburned carbon in the fly ash is 12.3 wt%, and the particle size. D50 is 22.4 μm.

The method for preparing the grout slurry is the same as in Example 1.

Example 3:

It is a grout slurry containing A liquid having a volume ratio of 1: 1 and B liquid, and the A liquid is 42.5 grade Portland cement 52 wt%, fly ash 33 wt%, slag 4.5 wt%, phosphorus. It contains 2.0 wt% of aluminum dihydrogen acid and 3.0 wt% of sodium hexametaphosphate, has a water-cement ratio of 0.7 to 1.1, and shows the chemical components of the cement and fly ash in Table 1 and shows the particle size. It is shown in Table 2.

The liquid B contains 22 wt% of water glass, 5 wt% of fly ash and water, the concentration of the water glass is 35 Baume degree, the amount of unburned carbon in the fly ash is 12.3 wt%, and the particle size. D50 is 22.4 μm.

The method for preparing the grout slurry is the same as in Example 1.

Example 4:

It is a grout slurry containing A liquid having a volume ratio of 1: 1 and B liquid, and the A liquid is 42.5 grade Portland cement 52 wt%, fly ash 33 wt%, slag 4.5 wt%, phosphorus. It contains 1.2 wt% of aluminum dihydrogen acid and 2.4 wt% of sodium hexametaphosphate, has a water-cement ratio of 0.8, and the chemical components of the cement and fly ash are shown in Table 1 and the particle size is shown in Table 2. The chemical composition of slag is shown in Table 3, and the particle size is shown in Table 4.

The liquid B contains 22 wt% of water glass, 16 wt% of fly ash and water, the concentration of the water glass is 35 Baume degree, the amount of unburned carbon in the fly ash is 12.3 wt%, and the particle size. D50 is 22.4 μm.

Table 3: Chemical composition of raw materials (wt%)

Table 4: Particle size distribution of raw materials (μm)

The method for preparing the grout slurry is the same as in Example 1.

Example 5:

As shown in FIG. 1, it is a slurry injection anchor rod for a ore column that injects the grout slurry of Example 1, and is a rod body 3, a slurry discharge hole 4, a drill 6, a tray 7, and an anti-friction gasket. 8 and a nut 9 are provided, a slurry discharge hole is provided at the tip of the outer rod body, an inner rod body is connected via a pin inside, and a slurry discharge hole 4 is provided inside the rod body 3. The slurry injection anchor rod is fixed to the hole via the tray 7, the anti-friction gasket 8, and the nut 9.

Slurry injection for ore column An anchor rod slurry injection method, the injection process is as shown in FIG. 2, and holes are made in the ore column 1 at 1/4 to 3/4 of a predetermined drilling length. The step of cleaning the hole, the end of the drill 6 of the rod body 3 is inserted into the hole, the other end of the rod body 3 is attached to the drilling machine, the hole is drilled to a predetermined drilling length, and the slurry injection pipe 2 is inside the rod body 3. The required amount of slurry 5 to be injected is calculated from the step of inserting the slurry and the predetermined anchor length, and the slurry injection pump is operated to inject the slurry 5 of Example 1 into the rod body through the slurry injection pipe 2 to form the slurry 5. The injection amount is controlled by a measuring device on the slurry injection pump, and by gradually pulling out the slurry injection pipe 2 while injecting the slurry, the slurry 5 fills the gap of the slurry injection pipe 2 and the slurry 5 is filled with the slurry discharge hole. The step of flowing out from the rod body 3 by 4 and filling the gap between the ore column rock layer and the gap between the inside of the ore column and the rod body, and stopping the slurry injection when the liquid level at the hole mouth becomes stable, and the rod body 3 This includes a step of sequentially attaching the tray 7, the anti-friction gasket 8 and the nut 9 to the exposed portion of the slurry 5, and a step of preloading the rod body 3 using a tensile tester after the slurry 5 has solidified. It is a column reinforcement method for the column type coal mining method, and the anchor rod work is performed by adopting the slurry injection method for the ore column, the injection pressure is 4.6 MPa, and the injection speed is 20 L / min. be. The schematic diagram of the column reinforcement is as shown in FIG. 3, the distance between the anchor rods and the row pitch are both designed to be 1.2 m, and the length of the anchor rods is 2.0 m.

Example 6: The difference from Example 5 is a method for reinforcing a ore column for a portland coal extraction method, which further includes spraying 10 cm thick concrete outside the ore column, and the concrete is foam concrete. Yes, Portland cement 40 wt%, waste concrete recycled raw material 52 wt%, water 25 wt%, fine sand 13 wt%, aluminum metaphosphate 3.0 wt%, sodium polyacrylate 0.22 wt%, hydrogen peroxide solution 1.05 wt%, foam It contains 0.07 wt% of stabilizer and 1.2 wt% of quick-setting admixture.

Example 7: The difference from Example 5 is a method for reinforcing a ore column for a portland coal extraction method, which further includes spraying 10 cm thick concrete outside the ore column, and the concrete is foam concrete. Yes, Portland cement 40 wt%, waste concrete recycled raw material 52 wt%, water 25 wt%, fine sand 13 wt%, aluminum metaphosphate 3.0 wt%, sodium polyacrylate 0.22 wt%, hydrogen peroxide solution 1.05 wt%, foam It contains 0.07 wt% of stabilizer and 1.2 wt% of quick-setting admixture.

Example 8: The difference from the fifth embodiment is that the rod body 3 is provided with one steel core wire penetrating both ends of the rod body 3.

Comparative Example 1: The difference from Example 1 is that the instep liquid does not contain aluminum dihydrogen phosphate.

Comparative Example 2: The difference from Example 1 is that the instep liquid does not contain sodium hexametaphosphate.

Comparative Example 3: The difference from Example 1 is that the instep liquid does not contain aluminum dihydrogen phosphate and sodium hexametaphosphate.

Comparative Example 4: The difference from Example 1 is that the amount of unburned carbon in the fly ash in the liquid B is 8.5 wt% and the particle size D50 is 22.4 μm.

Comparative Example 5: The difference from Example 1 is that the amount of unburned carbon in the fly ash in the liquid B is 12.3 wt% and the particle size D50 is 25.8 μm.

Comparative Example 6: The difference from Example 1 is that the concentration of water glass in the second liquid is 45 Baume degree.

Comparative Example 7: The difference from Example 6 is that the foamed concrete does not contain aluminum metaphosphate.

Comparative Example 8: The difference from Example 6 is that the foamed concrete does not contain sodium polyacrylate.

Comparative Example 9: The difference from Example 6 is that the foamed concrete does not contain aluminum metaphosphate and sodium polyacrylate.

Comparative Example 10: The difference from Example 5 is that the grout slurry is the grout slurry of Comparative Example 1.

Comparative Example 11: The difference from Example 5 is that the grout slurry is the grout slurry of Comparative Example 2.

Comparative Example 12: The difference from Example 5 is that the grout slurry is the grout slurry of Comparative Example 3.

Comparative Example 13: The difference from Example 5 is that the grout slurry is the grout slurry of Comparative Example 4.

Comparative Example 14: The difference from Example 5 is that the grout slurry is the grout slurry of Comparative Example 5.

Comparative Example 15: The difference from Example 5 is that the grout slurry is the grout slurry of Comparative Example 6.

Test Example 1:

Basic performance measurement of grout slurry

1. 1. PH measurement of grout slurry Table 5 shows the results of measurement with a precision test paper.

2. Measurement of water separation rate of grout slurry 200 mL of the prepared slurry was weighed in a 250 mL graduated cylinder of the same diameter, and quickly stirred with a glass rod in the graduated cylinder to uniformly mix the slurry. Then, the measuring cylinder is made to stand still on the test table, the suspended cement particles sink, and the thickness of the supernatant water gradually increases. The thickness of fresh water is read and recorded once at regular intervals until the readings are the same or slightly different three times in a row. The water separation rate (wt%) is the ratio of the volume of fresh water precipitated after the precipitation of cement particles was stopped to the total volume of the slurry, and the results are shown in Table 5.

3. 3. Viscosity measurement of grout slurry Table 5 shows the results of measurement with a 6-speed rotational viscometer.

4. Measurement of gelling time of grout slurry Put the weighed instep liquid and B liquid into two beakers, then pour the instep liquid into the B liquid bottle beaker according to the volume ratio, stir and immediately refill the mixed liquid. Place in a liquid beaker and repeat alternately until the slurry stops flowing or becomes viscous. The time measured from the mixing of the A and B liquids until the slurry stops flowing is the gelling time. The results are shown in Table 5.

5. Measurement of calculus rate of grout slurry The prepared slurry was poured into a 70.7 mm × 70.7 mm × 70.7 mm test mold, the surface was smoothed with a spatula, three samples were prepared for each group, and the slurry was allowed to stand for one day. After placing, the sample was die-cut, the height of the sample was measured with a grout, the average value was taken, and the calculus rate (%), which is the ratio of the volume of the calculus to the original volume of the slurry, was calculated. there were.

6. Grout Slurry Strength measurement of calculus body The stirred slurry was put into a test film of 70.7 mm × 70.7 mm × 70.7 mm to make a test piece, and after 24 hours, the film was removed and cured at 3d, 14d, 28d under standard curing conditions. A crush strength test was performed, three measurements were taken, the average value was taken, and the results are shown in FIG. When measured with a squeezer, the strain rate of the test piece was maintained at about 1 mm / min.

7. Measurement of volume change rate of glaut slurry stone body Dry shrinkage rate is AS2350.13-1995 / Amdt1-1997 "Methods Of Testing Portland And Blended Cements-Determination Of Drying Shrinkade Based on "for Fluidity of Cement Mortar", the formula for calculating the dry shrinkage rate is S = (L _2- L ₁ ) / L × 100 wt%, where S is the dry shrinkage rate of each material age of the sample. (Wt%), L ₁ represents the initial length (mm) of the sample, L ₂ represents the length (mm) from the curing of the sample to the predetermined age, and L represents the effective length of the sample. Represents the length (160 mm).

8. Measurement of ion erosion resistance of grout slurry stones

In the chlorine ion erosion test, the chlorine ion concentration in the erosion solution and the residual erosion solution is measured by the silver nitrate titration method in the chemical analysis method, and the concentration difference between the two solutions is tested to determine the chlorine ion erosion resistance of the stone. The formula for calculating the chlorine ion concentration is C = (C ₀ × V ₀ ) / V. In the formula, C ₀ represents the concentration (mol / L) of the AgNO _{3 solution, and V 0} is the measurement. The titration of the target solution _{represents the volume (mL) of AgNO 3} consumed, and V represents the volume (mL) of the target solution to be measured.

In the sulfate ion erosion test, a set concentration of erosion solution is prepared, the entire sample is immersed in the erosion solution, and the physical mechanical parameters of the samples at different immersion times are tested to perform a contrast analysis to evaluate the ion erosion resistance. Was realized.

Table 5 shows the basic performance measurement results of the grout slurry. The grout slurries of Examples 1 to 4 have a pH of 12 or more, satisfy the pH requirements required for alkali activation of flying ash and slag, and perform Examples 1 to 1. The fact that the water separation rate of the grout slurry of No. 4 is smaller than that of Comparative Examples 1 to 3 means that aluminum dihydrogen phosphate and sodium hexametaphosphate reduce the particle sedimentation of the grout slurry, give good stability to the grout slurry, and are used for construction. Explaining that the needs are satisfied, the grout slurry of Examples 1 to 4 having a viscosity value smaller than that of Comparative Examples 1 to 3 means that aluminum dihydrogen phosphate and sodium hexametaphosphate can increase the fluidity, and the construction work. By observing the gelation time of the grout slurry of Examples 1 to 4, the grout slurry was prepared from flying ash in the liquid B and aluminum dihydrogen phosphate and hexametaphosphate in the liquid A. The gelation time of the slurry can be adjusted by adjusting the amount of sodium added, the gelation time of the slurry can be adjusted from several tens of seconds to several tens of minutes, and injection is performed at a volume ratio of 1: 1. We found that the injection was easy. Since the calculus rate of the grout slurries of Examples 1 to 4 was higher than that of Comparative Examples 1 to 3, it was found that aluminum dihydrogen phosphate and sodium hexametaphosphate can improve the calculus rate of the grout slurry. As for the strength measurement of the grout slurry calculus, as shown in FIG. 4, the crushing strength of the grout slurry calculus of Examples 1 to 4 was larger than that of Comparative Examples 1 to 6 in curing 3d, 14d and 28d, and diphosphate diphosphate. It was found that aluminum hydrogen hydrogen and sodium hexametaphosphate improve the crushing strength of the slurry stone body, and the flying ash having an unburned carbon content of 10 to 15 wt% and a particle size D50 of 15 to 35 μm contributes to the strength of the stone body. However, it can be seen that water glass having a concentration of 25 to 45 bohmes can increase the crushing strength of the calculus. The drying shrinkage of the grout slurry calculus is as shown in FIG. 5, the drying shrinkage of the grout slurry calculus of Examples 1 to 4 is low, and there is almost no volume shrinkage phenomenon. The reaction concentration of chloride ions in the grout slurry calculus is as shown in FIG. 6, and the reaction concentration of chloride ions in the grout slurry calculus in Example 4 is much higher than that in Example 1. Explain that the ability to solidify ions can be enhanced and the chloride ion erosion resistance of grout slurry calculus is improved. As shown in FIG. 7, the corrosion resistance coefficient of the grout slurry calculus in the erosion solution (concentration 5.0%) is larger than 0.8 in the grout slurry calculus of Example 4, and the erosion resistance is acceptable. It was found to be present, indicating that the slag was able to increase the ability of the calculus to resist sulphate entry and improved the sulphate erosion resistance of the grout slurry calculus.

Table 5: Measurement results of basic performance of grout slurry

Test Example 2:

Performance measurement of foam concrete

1. 1. Measurement of dry apparent density of foamed concrete For a foamed concrete sample of 70.7 mm x 70.7 mm x 70.7 mm, measure the length, width, and height one by one, calculate the volume of the sample, and then twice. Table 6 shows the results of calculating the apparent density of foamed concrete from the volume and the weight after drying after drying until the weight difference of the weighing is less than 1 g.

2. Porosity measurement of foamed concrete The porosity e (%) of foamed concrete is measured and calculated using the mass volume direct calculation method, and the calculation formula is e = (1-M / (V × ρ _s )) × 100 wt. % (1), in the formula: M represents the mass (g) of the foamed concrete sample after drying, ρ _s represents the apparent dry density (kg / m ³ ) of the foamed concrete sample solid, and V is , Represents the volume (mm3) of the foamed concrete sample.

3. 3. Measurement of sound absorption coefficient of foamed concrete The quality of sound absorption performance of a material is expressed by the sound absorption coefficient α, and the ratio of the absorbed sound energy (or the part not reflected on the surface) to the incident sound energy, that is, α = 1-E _γ / E _α = (E _α + E _β ) / E ₀ . In the formula: E _α represents the sound energy absorbed by the material itself, E _β represents the transmitted sound energy, E _γ represents the reflected sound energy, and E ₀ is the total sound energy incident in a unit time. Represents.

4. Noise reduction coefficient measurement of foamed concrete The noise reduction coefficient is a single numerical evaluation of the material sound absorption capacity as well as the sound absorption coefficient. The sound absorption of a material is related to frequency, that is, different frequencies have different sound absorption rates of the same material. The noise reduction coefficient is obtained by taking the average value of the sound absorption coefficient of the four frequency bands of 250 Hz, 500 Hz, 1000 Hz, and 2000 Hz, and is expressed by NRC. The coefficient levels are NRC> 0.80 class I, NRC 0.80 to 0.60 class II, NRC 0.60 to 0.40 class III, NRC 0.40 to 0.20. Evaluate to IV grade. However, NRC = (α ₂₅₀ + α ₅₀₀ + α ₁₀₀₀ + α ₂₀₀₀ ) / 4. In the formula, NRC represents the noise reduction coefficient, α ₂₅₀ represents the sound absorption coefficient at the frequency of 250 Hz, α ₅₀₀ represents the sound absorption coefficient at the frequency of 500 Hz, and α ₁₀₀₀ represents the sound absorption coefficient at the frequency of 1000 Hz. , Α ₂₀₀₀ represents the sound absorption coefficient of the frequency of 2000 Hz.

5. Strength measurement of foamed concrete

With reference to JG-T266-2011 "Formed concrete", a 70.7 mm × 70.7 mm × 70.7 mm foam concrete sample of natural curing 28d was dried, and then the strength was measured with a compression tester.

Table 6 shows the basic performance measurement results of foamed concrete. Compared with Comparative Examples 7, 8 and 9, the foamed concrete of Example 6 had a relatively low dry volume, a high pore ratio, a sound absorption coefficient and a noise reduction coefficient. Explaining that the foamed concrete of the present invention has a high noise reducing effect and can provide a good environment for mining, the foamed concrete of Example 7 is compared with Example 6. It was explained that continuous fibers can enhance the noise reduction effect of concrete in that the dry volume of concrete is lower and the pore ratio, sound absorption coefficient and noise reduction coefficient are higher. FIG. 8 shows the 28d crushing strength of foamed concrete, the highest 28d crushing strength of concrete of Example 7, followed by Example 6, and Comparative Examples 7, 8 and 9 of the present invention. Explain that foamed concrete has a high crushing strength and continuous fibers can increase the crushing strength of concrete.

Table 6: Measurement results of basic performance of foamed concrete

Test Example 3: Evaluation of ore column reinforcement effect The wave velocity of the bedrock was measured using sound waves, and the reinforcement effect was analyzed by the change in the wave velocity of the bedrock at the same position. The instruments used for the test mainly include a sound wave tester, a test probe, a signal connection line, and the like. Perform a rock mass ultrasonic test by the two-hole intra-hole measurement method. The test range was the face surface of the slurry injection section, and in-situ rock wave velocity tests were performed on the test rock before and after the injection work. The rock mass perfection index is calculated based on _{K v} = (V _pm / V _pr ) ^{2. In} _{the formula, V pm} represents the rock elastic longitudinal wave velocity (km / s), and V _pr is the rock elastic longitudinal wave. Represents speed (km / s).

Correspondence between the bedrock perfection index K _v and integrity about qualitatively separated rock are shown in Table 7. The rock integrity index this time was calculated using the longitudinal wave velocity test results of the boring core corresponding to the test rock. The calculation results are as shown in FIG. 9, the degree of completeness of the rock mass before slurry injection is crushed, and the degree of completeness of the rock mass injected with slurry by the methods of Examples 5 to 7 is perfect, and the comparative example. The degree of completeness of the rock mass slurry-injected by the methods 10 to 12 is relatively perfect, and the degree of completeness of the rock mass slurry-injected by the methods of Comparative Examples 13 to 15 is perfect. This explains that the column reinforcement method of the present invention can guarantee the integrity of the column and ensure the normal and safe mining of the mine.

Table 7: K _v and qualitatively separated by correspondence between the integrity of the order of the bedrock

Since the prior art in the above embodiment is a prior art known to those skilled in the art, detailed description thereof will be omitted here.

The above embodiments are for explaining the present invention, do not limit the present invention, and can be variously modified and modified without departing from the spirit and scope of the present invention. It is obvious to the trader. Therefore, all equivalent technical solutions are also included in the scope of the present invention, and the scope of claims of the present invention should be limited by the scope of claims.

1 Slurry 2 Slurry injection pipe 3 Rod body 4 Slurry discharge hole 5 Slurry 6 Drill 7 Tray 8 Anti-friction gasket 9 Nut 10 Slurry injection anchor rod

Claims (9)

A grout slurry containing A liquid and B liquid, wherein the A liquid contains 45 to 63 wt% of Portland cement, 25 to 46 wt% of fly ash, 3 to 7 wt% of slag, and aluminum dihydrogen phosphate. It contains 0 to 2.0 wt% and 2.0 to 3.0 wt% of sodium hexametaphosphate, has a water-cement ratio of 0.7 to 1.1, and the liquid B is 15 to 25 wt% of water glass. fly ash 5～28Wt% and water only contains unburned carbon content in the fly ash is 10 to 15 wt%, particle size D50 is 15～23Myuemu, grout slurry, characterized in that. The grout slurry according to claim 1, wherein the volume ratio of the A liquid to the B liquid is 1: 1. A slurry injection anchor rod for an ore column, which comprises injecting the grout slurry according to claim 1 or 2. The slurry injection anchor rod includes a rod body (3), a slurry discharge hole (4), a drill (6), a tray (7), an anti-friction gasket (8), and a nut (9). The slurry discharge hole (4) is provided at the tip of the outer rod body, the inner rod body is connected to the inside of the outer rod body via a pin, and the inside of the rod body (3) is connected. The slurry discharge hole (4) is provided, and the slurry injection anchor rod is fixed to the hole by the tray (7), the anti-friction gasket (8), and the nut (9). The slurry injection anchor rod for a ore column according to claim 3, which is characterized. Slurry injection for ore column This is a slurry injection method using an anchor rod, in which holes are made in the ore column (1) at 1/4 to 3/4 of the predetermined drilling length, and the holes are cleaned, and the rod body (3). ), Insert the end of the drill (6) into the hole, attach the other end of the rod body (3) to the drilling machine, make a hole to the predetermined drilling length, and insert the slurry injection pipe (2) into the rod body (3). The step of inserting and the slurry injection tube (2) are gradually injected while injecting the slurry (5) according to claim 1 or 2 or 3 into the rod body (3) by the slurry injection tube (2). The step of stopping the slurry injection when the liquid level at the hole is stable, and the tray (7), the anti-friction gasket (8), and the nut (9) are attached to the exposed part of the rod body (3) in this order. A slurry injection method using a slurry injection anchor rod for an ore column, comprising: a step and a step of preloading the rod body (3) using a tensile tester after the slurry (5) has solidified. A method for reinforcing a column for a column-type coal mining method, wherein an anchor rod operation is performed on the column by the slurry injection method according to claim 5. Ore pillar reinforcement method for the pillar tufts formula mining method further comprises spraying concrete outside ore pillar, the layer thickness of the concrete is 7～12Cm, according to請Motomeko 6, characterized in that Column reinforcement method for column-type coal mining method. The concrete is gas concrete, foamed co dried apparent density of Nkurito is 1,100 to 1500 kg / m ^3, ore pillar reinforcement method for pillars tufts formula mining method according to claim 7, characterized in that. The method for reinforcing columns for the column-bundle type coal mining method according to claim 7 , wherein the concrete contains continuous fibers.

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