JP2951854B2 - Pulverized coal transportability improver - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pulverized coal transportability improving agent which improves the transportability of pulverized coal blown from an injection port of a metallurgical furnace or a combustion furnace and enables stable pulverized coal to be blown in a large amount. The present invention relates to a method of operating a metallurgical furnace or a combustion furnace using the same.

[0002]

2. Description of the Related Art In the operation of a metallurgical furnace, for example, a blast furnace,
A method of charging coke and iron ore alternately from the furnace top has been commonly used.In recent years, a part of coke charged from the furnace top has been converted into pulverized coal that is inexpensive, has high flammability, and has a high calorific value. Alternative methods are being actively pursued by blowing from the blast furnace inlet with hot air. Such a pulverized coal blowing operation method is superior in that the fuel cost can be reduced as compared with the all-coke operation.

[0003] Coal has also been reviewed as an alternative to heavy oil as fuel for combustion furnaces such as boilers. Examples of the form of use of coal in the combustion furnace include CWM (coal-water slurry), COM (coal-fuel mixed fuel), and pulverized coal. Among them, the pulverized coal combustion furnace requires other media such as water and oil. And because it does not, has been attracting attention. However, this pulverized coal combustion furnace also has the same problems as the use of pulverized coal in blast furnace operation.

[0004] In pulverized coal injection, pulverized coal production by dry grinding of raw coal, classification, storage and discharge in a hopper,
Following the process of gas transport in pipes, blowing into metallurgical furnaces or combustion furnaces from injection ports, and burning in metallurgical furnaces or combustion furnaces, the following describes the discharge of pulverized coal from hoppers and gas transport in pipes as follows. There is a problem.

[0005] That is, the basic properties of the powder such as the fluidity of the pulverized coal change depending on the type of coal, the particle size, and the moisture of the pulverized coal to be discharged and transported. For this reason, if the basic physical properties of pulverized coal are out of the optimal range, shelving and blowing through the hopper,
This may cause a blockage of the pipe during the gas transportation, and it is difficult to continue the stable pulverized coal injection for a long period of time.

In order to solve such problems, it has been considered to improve the transportability of pulverized coal, and various methods have been conventionally proposed. For example, put char in pulverized coal for 5-20
% (Japanese Patent Laid-Open No. 4-268004), an inert in coal (micrinite specified in JIS M8816-1979,
1/3 Semi-Fujinit, Fujinit, and Mineral Substances) Finely crushed after adjusting the amount of components (Japanese Unexamined Patent Publication No.
No. 9518, JP-A-5-25516, JP-A-5-2224
No. 15), the type of pulverized coal to be blown is limited to be equal to or higher than the reference value of the blast furnace using the fluidity index (JP-A-4-224610), and the coefficient of friction between the pulverized coal and the piping is adjusted ( Japanese Patent Application Laid-Open No. 5-214417) and controlling the water content in pulverized coal to an appropriate value (Japanese Patent Application Laid-Open No. 5-78675). As a method of improving the pulverization efficiency of pulverized coal, a method of adsorbing a dispersant (JP-A-63-22)
However, this method does not mention the transportability of pulverized coal.

[0007]

However, in the above-described method, the types of coal that can be used for pulverized coal injection are limited, or the hanging and blowing of shelves in a hopper, and the blockage of pipes are not sufficiently resolved, However, there is a problem that the cost of the apparatus and equipment is high, and no practically satisfactory method has been provided.

Further, for example, in the current method of operating a blast furnace,
The amount of pulverized coal injected from the injection port is about 50 to 250 kg / it of pig iron, but it is desirable to further increase the amount of pulverized coal to be injected from the viewpoint of cost. However, in the above-mentioned method, since the transportability of the pulverized coal is not always sufficient, it is not possible to achieve a significant improvement in the amount of pulverized coal to be blown.

Therefore, an object of the present invention is to solve the above-mentioned problems of the conventional method, to improve the pulverized coal transportability,
It is an object of the present invention to remove the limitation of the type of coal, to prevent clogging of pipes and hanging of shelves in a hopper, and to enable a large amount of pulverized coal to be stably blown.

[0010]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to achieve the above object, and have found that an organic compound having a polar group and substantially soluble in water has an average HGI of raw coal of 30 or more. It has been found that by impregnating the pulverized coal, the transportability of the pulverized coal is dramatically improved, and the present invention has been completed.

That is, the present invention comprises an organic compound having a polar group and substantially soluble in water, and has an average HGI of raw coal.
An object of the present invention is to provide a pulverized coal transportability improver characterized by being used for 30 or more dry pulverized coals, and a pulverized coal comprising such a transportability improver and fine pulverized coal. Also,
The present invention provides a method for operating a metallurgical furnace or a combustion furnace using such a transportability improver and fine pulverized coal.

Here, the term “water-soluble organic compound” refers to a 10-fold (by weight) amount of water (10
℃ deionized water) does not cause white turbidity, and
The amount of the organic compound remaining on the filter when filtered using a 0.1 μm membrane filter is 10% by weight or less of the amount of the organic compound used in the test.

The method of operating a metallurgical furnace or a combustion furnace using the transportability improver of the present invention may be 0.01% by weight or more and 10% by weight or more based on the pulverized coal blown from the inlet of the metallurgical furnace or the combustion furnace.
Or less, preferably from 0.05% by weight to 5% from the effect of improving the transportability.
It is characterized in that a transportability improver of not more than% by weight is added to the pulverized coal to reduce the triboelectric charge of the pulverized coal, and the pulverized coal is blown from a blowing port of a metallurgical furnace or a combustion furnace. It is preferable that the amount added to the pulverized coal is 0.01% by weight or more from the viewpoint of the effect of improving transportability, and even if added in excess of 10% by weight, the effect corresponding to the added amount is not recognized and it is economically disadvantageous. Become.

The pulverized coal to be used in the present invention is dry pulverized coal having an average HGI of 30 or more. here,
"Dried" means that the water content by the dry weight loss measurement method in air defined in JIS M 8812-1984 is 10% by weight or less. Pulverized coal having a high moisture content is not suitable as a fuel for metallurgical furnace injection or combustion furnace use.

Although the pulverized coal having an average HGI of 30 or more of the raw coal has poor transportability, the use of the transportability improver of the present invention enables the smooth transport of the pulverized coal. Further, the present invention is also effective for pulverized coal having an average HGI of 50 or more of raw coal, which is considered to be extremely difficult to transport gas by the current technology.

Here, "HGI" means "Hardgro".
ve Grinding Index ”(crushing ability index)
, Which is an index that indicates the grinding resistance of coal as defined by ASTM D409.

As a result of the study, the present inventors have clarified that the above-mentioned problem of pulverized coal is caused by charging between the pulverized coals, and solved the above-mentioned problems by reducing the triboelectric charge amount of the pulverized coal. And found that the magnitude of the triboelectric charge between the pulverized coal is the fluidity index of the pulverized coal itself,
It was found that there was a strong correlation with pipe transport characteristics.

That is, coal having poor transportability has more fine coal adhered around pulverized coal having a size of about the average particle diameter, and pulverized coal having good transportability has less fine coal deposited around. Not. These fine coals strongly adhere to ordinary pulverized coal, causing the apparent shape of the pulverized coal to be distorted. Finer coal adhering to one pulverized coal also strongly adheres to other pulverized coal The fluidity of pulverized coal deteriorates as if it plays a role as a binder. It is shown that the force between these finer coals and ordinary pulverized coal is due to Coulomb attraction,
m is measured by the blow-off method (usually used to measure the triboelectric charge between different substances having different particle size distributions, for example, between toner and carrier). I was able to confirm. Also, the amount of decrease in the triboelectric charge amount is [average HGI of raw coal] × 0.00
It has been found that the pulverized coal has an improved transportability if it is at least 7 μC / g. Furthermore, the triboelectric charge of the original pulverized coal is 2.8μ.
In the case of pulverized coal with a very poor transportability of more than C / g, the triboelectric charge can be reduced to 2.8 μC by adding a transportability improver.
/ G or less, thereby improving the transportability. In addition,
In the present invention, the triboelectric charge means a value measured by a method described in detail in Examples described later.

As the index of the transportability of the pulverized coal, a fluidity index and a pressure loss in a pipe transportation test described in detail in Examples described later were used. The fluidity index can simulate the discharge characteristics in a hopper or the like, and the pressure loss can simulate the flow characteristics in a pipe during gas transport. As a guide for improving transportability, it is necessary to improve the fluidity index by 3 points or more and to reduce the pressure loss by 3 mmH ₂ O / m or more. For pulverized coal with extremely poor transportability, the fluidity index must be 40 or more and the pressure loss must be 16 mmH ₂ O / m or less.

The present inventors have further studied and found that as a compound that reduces the triboelectric charge of such pulverized coal and improves the transportability of the pulverized coal, it has a polar group and is substantially soluble in water. Have been found to be suitable.

The transportability improver of the present invention reduces the triboelectric charge of pulverized coal, and contains carboxylic acid, sulfonic acid or their salts, amides, sulfates or their salts, amine salts, nitriles in the molecule. Having at least one polar group such as a phenol group or a salt thereof.

Particularly, the transportability improver preferably used in the present invention is one or more selected from anionic surfactants, cationic surfactants, amphoteric surfactants, lower fatty acids and lower fatty acid salts. Is mentioned.

It is preferable to dissolve them in a solvent as it is or at an appropriate concentration and to use them in a liquid form in order to uniformly disperse them. In this case, the concentration of 1% by weight or more is more convenient for drying the solvent. The solvent is preferably water for drying.

The effect of adding the transportability improver of the present invention is the same before and after pulverizing raw coal.

Specific examples of the compounds exemplified above as the transportability improver used in the present invention are shown below.

(A) Examples of the anionic surfactant, the cationic surfactant, and the amphoteric surfactant include the following.

[0027]

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2. Alkyl ether carboxylates _{RO (CH 2 CH 2 O)} n CH 2 COOM _{[R: C 6 ~C 20, M} : H, Na, K, NH 4, or an organic amine salt, n: 0 to 40] 3. 3. Lignin sulfonic acid salt Lignin sulfonic acid sodium salt, calcium salt, potassium salt, ammonium salt, triethanolamine salt, etc. Acylated peptides RCO (NHR'CO) _n OM _{[R, R ': C 6 ~C} 20, M: H, Na, K, NH 4, or an organic amine salt, n: 1 to 40]

[0029]

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[0030]

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[0031]

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11. Sulfated oil Roto oil (low sulfated castor oil), low sulfated olive oil, sulfated tallow, sulfated peanut oil 12. Higher alcohol sulfate ester salt RSO ₃ M [R: C ₆ -C _{20, M: H, Na,} K, NH 4, an organic amine salt, etc.]

[0033]

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14. Alkyl ether sulfate R (OCH ₂ CH ₂ ) _n OSO ₃ M [R: C ₆ -C ₂₀ , M: H, Na, K, NH ₄ , organic amine salts, etc., n: 0-40 ]

[0035]

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[0036]

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18. Sulfuric acid ester salt of fatty acid alkylol amide RCONHCH ₂ CH ₂ OSO ₃ M [R: C ₆ -C ₂₀ , M: H, Na, K, NH ₄ , organic amine salt, etc.]

[0038]

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[0039]

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21. Molecular weight 10 obtained from the following (1) and (2)
(1) α, β-unsaturated carboxylic acid or its salt, sulfonic acid group-containing vinyl compound or its salt (2) acrylonitrile, vinylpyrrolidone and carbon number 2
(A) one or more polymers or copolymers selected from (1) (1) (b) one or more selected from (1) and (2) selected from (2) One or more copolymers. Examples of the vinyl monomer as a raw material of the copolymer include vinyl pyrrolidone, acrylonitrile; acrylic acid, methacrylic acid, maleic acid or alkali metal salts and ammonium salts of these acids; vinyl sulfonic acid, methallyl sulfonic acid , 2-acrylamido-2-methylpropanesulfonic acid, styrenesulfonic acid or alkali metal salts or ammonium salts of these acids.

22. Average of one or more compounds selected from naphthalenesulfonic acid or a salt thereof, melaminesulfonic acid or a salt thereof, phenolsulfonic acid or a salt thereof, ligninsulfonic acid or a salt thereof, and an aliphatic aldehyde Condensate having a molecular weight of 1,000 to 100,000. Examples of the salt include an alkali metal salt and an ammonium salt.

23. Aliphatic amine salt • Primary amine RNH ₂ X [R: C ₆ -C ₂₀ , X: inorganic acid, organic acid]

[0043]

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[0044]

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[0045]

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29. A homopolymer of a nitrogen-containing monomer or a salt thereof represented by the following general formulas (I) to (IX) or a copolymer of two or more thereof.

[0047]

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[0048]

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[0049]

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The following are specific examples of these monomers. That is, examples of the formula (I) include 3-methacryloxy-2-hydroxypropyldimethylamine,
-Methacryloxy-2-hydroxypropylethylmethylamine, 3-methacryloxy-2-hydroxypropyldiethylamine, 3-methacryloxy-2-hydroxypropyldipropylamine and the like; Examples of the formula (II) include N, N-dimethylamino Methylene capped ethylene glycol methacrylate, N, N-dimethylaminopropylene capped ethylene glycol methacrylate, N, N-dimethylamino methylene capped diethylene glycol methacrylate, N, N-dimethylaminoethylene capped diethylene glycol methacrylate, N, N-dimethylamino Propylene-capped diethylene glycol methacrylate, N, N-diethylaminomethylene-capped ethylene glycol methacrylate, N, N- Ethylaminoethylene capped ethylene glycol methacrylate, N, N-diethylaminopropylene capped ethylene glycol methacrylate, N, N-diethylaminomethylene capped diethylene glycol methacrylate, N, N-diethylaminoethylene capped diethylene glycol methacrylate, N, N-diethylaminopropylene cap Examples of formula (III) include N-2-hydroxymethyl-2-α-methylvinylimidazole and N-2-hydroxyethyl-2.
-Α-methylvinylimidazole, N-2-hydroxypropyl-2-α-methylvinylimidazole and the like;
Examples of the formula (IV) include N, N-dimethylmethyleneimine methacrylamide, N, N-dimethylethyleneimine methacrylamide, N, N-dimethyldimethyleneimine methacrylamide, N, N-dimethyldiethyleneimine methacrylamide, Examples of the formula (V) include N, N-diethylmethyleneimine methacrylamide, N, N-diethylethyleneimine methacrylamide, N, N-diethyldimethyleneimine methacrylamide, N, N-diethyldiethyleneimine methacrylamide and the like. Is N, N-dimethylaminoethyl acrylate, N,
N-diethylaminoethyl acrylate, N, N-dimethylaminoethyl methacrylate, N, N-diethylaminoethyl methacrylate, N, N-dimethylaminopropyl acrylamide, N, N-diethylaminopropyl acrylamide, N, N-diethylaminopropyl methacrylamide and the like Examples of the formula (VI) include N, N-dimethylaminoethylethylene, N, N-diethylaminomethylethylene, N, N-dimethylaminomethylpropene, N, N-diethylaminomethylpropene and the like;
Examples of the formula (I) include vinylpyridine and the like; examples of the formula (VIII) include vinylpiperidine and vinyl-N-methylpiperidine; and examples of the formula (IX) include vinylbenzylamine and vinyl-N, N -Dimethylbenzylamine and the like.

30. α, β-unsaturated carboxylic acid, its salt or its derivative, sulfonic acid group-containing vinyl compound or its salt, acrylonitrile, vinylpyrrolidone and carbon number 2
And one or more vinyl monomers selected from the group consisting of aliphatic olefins of the formulas (I) to (IX)
And a copolymer with one or more of the nitrogen-containing monomers or salts thereof. Examples of the vinyl monomer as a raw material of the copolymer include vinylpyrrolidone, acrylonitrile; acrylic acid, methacrylic acid, maleic acid or alkali metal salts, ammonium salts, amide compounds or esterified products of these acids; vinyl sulfone Examples thereof include acids, methallyl sulfonic acid, 2-acrylamido-2-methylpropane sulfonic acid, p-styrene sulfonic acid, and alkali metal salts or ammonium salts of these acids.

31. A ring-opened polymer of ethyleneimine, a salt thereof, a quaternary ammonium salt thereof, or a derivative thereof. As a specific example, for example, the repeating unit is represented by the following general formula (X) and the average molecular weight is 1,000 to 1,000,000.
One.

[0053]

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32. A polycondensation product of an aliphatic dicarboxylic acid and a polyethylene polyamine or a dipolyoxyethylene alkylamine, a salt thereof or a quaternary ammonium salt thereof, specifically, for example, when the repeating unit thereof has a general formula ( XI) a polycondensate of a polyethylene polyamine and an aliphatic dicarboxylic acid represented by the general formula (XII) and a polycondensate of an aliphatic dicarboxylic acid and a molecular weight of 1,000 to 1,000,000 One.

[0055]

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33. Dihaloalkane-polyalkylenepolyamine polycondensation product, salt thereof or quaternary ammonium salt Specific examples thereof include dichloroethane such as 1,2-dichloroethane, 1,2-dibromoethane and 1,3-dichloropropane. A quaternary ammonium salt of a condensation polymer of a haloalkane and a polyalkylene polyamine having two or more tertiary amino groups in the molecule, having an average molecular weight of 1,000 to 1,000,
000. Examples of the polyalkylene polyamine used here include tetramethylethylenediamine, tetramethylpropylenediamine, pentamethyldiethylenetriamine, hexamethylenetetramine, and triethylenediamine.

34. Epihalohydrin-amine condensation polymer,
Specific examples of the salt or the quaternary ammonium salt include those having a repeating unit represented by the following formula (XIII) and having an average molecular weight of 1,000 to 1,000,000.

[0058]

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35. Chitosan salt, starch or cellulose, or a cationically modified product thereof.

[0060]

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37. Aminocarboxylate RNH (CH ₂ ) _n COOM [R: C ₆ -C ₂₀ , n: 1-2, M: H, Na, K, NH ₄ ,
Organic amine salts, etc.)

[0062]

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39. Lecithin Among these surfactants, those having 3, 21, 22, 29 to 35 are particularly effective.

(B) The lower fatty acid may have 1 to 8 carbon atoms.
And specific examples thereof include formic acid, acetic acid, propionic acid, oxalic acid, malonic acid, succinic acid, adipic acid, maleic acid, caproic acid and the like. The lower fatty acid salts include formic acid, acetic acid, propionic acid, oxalic acid, malonic acid, succinic acid, adipic acid,
Sodium, potassium, ammonium salts such as maleic acid and caproic acid, and the like.

The metallurgical furnaces and combustion furnaces to be used in the present invention include furnaces using pulverized coal as fuel and / or a reducing agent (blast furnace, cupola, rotary kiln, smelting reduction furnace, cold iron source melting furnace, boiler, etc.). And a carbonization apparatus using pulverized coal (eg, a fluidized-bed carbonization furnace, a gas reforming furnace, etc.).

[0066]

According to the present invention, by reducing the triboelectric charge of pulverized coal, the transportability of pulverized coal having an average HGI of 30 or more of raw coal is improved, and a large amount of such pulverized coal can be transported. . In addition, by adding the transportability improver of the present invention to coal having poor transportability, the transportability can be improved and a large amount of coal can be transported, so that the types of coal that can be used for pulverized coal injection can be expanded.

At the same time, since the pulverized coal to be blown from the blowing port treated with the transportability improver of the present invention has a good fluidity, it can be prevented from hanging on the shelf in the hopper. The temporal change of the cutout amount and the deviation of the distribution amount can be greatly reduced.

[0068]

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these examples.

Examples 1 to 88 and Comparative Examples 1 to 7 [1] Pulverization of raw coal and preparation of pulverized coal for evaluation Pulverization of raw coal and addition of a transportability improver were performed in the following procedure. The raw coal and the transportability improver shown in Tables 1 to 9 are put into a pulverizer [small pulverizer SCM-40A (manufactured by Ishizaki Denki Seisakusho)], pulverized and mixed, and adjusted by a pulverization time to obtain a required particle size. . At that time, the transportability improver is dissolved in a solvent shown in Tables 1 to 9,
Raw coal is added while pulverizing so that the amount added to the pulverized coal becomes the amount shown in the table. After drying at 105 ℃ for 1 hour, moisture in pulverized coal is 0.5 ~ 1.0
Adjust to be%. The mixture was sieved through 106 μm to obtain pulverized coal having a particle size of 106 μm or less. The water content (0.5-1.0%) and the volume average particle size (75 μm) in the pulverized coal were all adjusted to the same value. Here, the volume average particle diameter is defined by the following equation.

[0070]

(Equation 1)

[2] Evaluation of Pulverized Coal The pulverized coal thus obtained had a triboelectric charge, a fluidity index,
The effect of the additive on pipe transport characteristics was investigated by the following method.

<Method of Measuring Friction Charge Amount> The friction charge amount of pulverized pulverized coal is measured by a blow-off measuring device as shown in FIG. In FIG. 1, 1 is a compressed gas, 2 is a nozzle, 3 is a Faraday gauge, 4 is a mesh having an opening of 38 μm, 5 is a dust hole, and 6 is an electrometer. Such a blow-off device is usually used to measure the triboelectric charge between different substances having a difference in particle size (for example, toner and carrier).
m, and 0.1-0.3 g of pulverized coal is put on it, and compressed gas (for example, air) is applied thereto at 0.6 kgf / cm ^2.
By spraying the powder at a pressure of 3 μm, the pulverized coal having a size of 38 μm or less is blown off to a dust hole, and the triboelectric charge of the pulverized coal having a size of 38 μm or less is measured.

<Method of Measuring Fluidity Index> The fluidity index is an index for evaluating the fluidity of powder, and the four factors (angle of repose, degree of compression, degree of spatula, degree of agglomeration) of the powder are indexed. It is obtained from the sum of the indices. The details of the measurement method and index of each factor are described in the “Powder Engineering Handbook” (edited by the Society of Powder Engineering, published by Nikkan Kogyo, 1987).
Pp. 152. The method for measuring each factor is described below. 1. Angle of repose: The powder is passed through a standard sieve (25 mesh), then poured through a funnel onto a disk having a diameter of 8 mm, and the inclination angle of the formed sedimentary layer is measured. 2. Compressibility: Cylindrical container for filling powder (volume 100c)
m ³ ), the bulk density ρ _s (g / c
m ³ ) and the dense packing density ρ _c (g / cm ³ ) after the tapping has been performed a certain number of times (180 times), the compression degree ψ (%) is determined by the following equation. ψ = (ρ _c −ρ _s ) × 100 / ρ _c (%) Spatula angle: Insert a spatula (spatula) of a certain width (22 mm) into the deposited powder, lift it and measure the inclination angle of the powder placed on it. Next, a slight impact is applied to the spatula, the angle is measured again, and the average value of the two is defined as the spatula angle. 4. Cohesion: Three types of sieves with different openings (each sieve is 60, 100, 200 mesh from the top), 2 g of powder is placed on the top, and these are vibrated at the same time. The amount of powder in the upper sieve / 2 g) × 100, the amount of powder in the middle sieve / 2 g) × 100 × 3/5, and the amount of powder in the lower sieve / 2 g ) × 100 × 1/5 It is determined by summing three calculated values. In the case of pulverized coal as used in the present invention, there is no difference in the amount of pulverized coal remaining in each sieve, and it is difficult to calculate the degree of agglomeration.In the present invention, the repose angle, the degree of compression, the spatula angle The liquidity index was evaluated from the total of the three points.

<Method of Measuring Pipe Transport Characteristics>"CAMP-I
SIJ Vol. 6 "(1993), p. 91, the pipe transport characteristics were evaluated by measuring the pressure loss with the apparatus of FIG. In FIG. 2, 7 is pulverized coal, 8 is a table feeder, 9 is a flow meter, and 10 is a pipe diameter of 1.
2.7mm horizontal tube, 11 means cyclone. This apparatus is for transporting the pulverized coal 7 discharged from the powder feeder 8 by gas using a carrier gas and measuring the pressure loss between the pressure measurement holes (P ₁ , P ₂ ). The experimental conditions were as follows. Pulverized coal supply 0.8 kg / min Carrier gas Nitrogen (N ₂ ) Carrier gas amount 4 Nm ³ / h (67 liters / min) Transport time 6 minutes Evaluation is as follows. 1. Pressure loss The pressure gauges P ₁ and P ₂ sample data at 500 Hz. The pressure drop is P ₁ during the transport time (6 minutes).
It is given by the total average of -P _2.

[0075]

(Equation 2)

Tables 1 to 9 show the results.

[0077]

[Table 1]

[0078]

[Table 2]

[0079]

[Table 3]

[0080]

[Table 4]

[0081]

[Table 5]

[0082]

[Table 6]

[0083]

[Table 7]

[0084]

[Table 8]

[0085]

[Table 9]

The following compounds were evaluated in the same manner as described above. The results are shown in Tables 10 to 13.

(A) Phosphate of a polymer of diethylaminomethyl methacrylate (Mw = 10000) (B-1) Borate of diethylaminoethyl methacrylate / vinylpyrrolidone / sodium acrylate = 5/4/1
(Shown in molar ratio; the same applies hereinafter) (Mw = 20)
(B-2) 〃 (Mw = 50,000) (B-3) 〃 (Mw = 5000) (B-4) 〃 (Mw = 1500) (C) Phosphate of diethylaminoethyl methacrylate / sodium methacrylate = 4/5 copolymer (Mw = 20,000) (D) Ring opening polymer of ethyleneimine phosphate (Mw = 10
(E) Copolymer of dimethylaminoethyl methacrylate ethyl phosphite / sodium acrylate = 3/1 (Mw = 300,000) (F) Ethyl phosphonate of dimethylaminoethyl methacrylate / 2-acrylamino Copolymer of -2-methylpropanesulfonic acid sodium = 4/1 (Mw = 100,000) (G) Vinylpyridine phosphate / vinylpyrrolidone /
Copolymer of sodium acrylate = 6/3/1 (Mw = 450,000) (H) Polycondensate of thiophosphate of diethylenetriamine and dimer acid (Mw = 800,000) (I) Phosphoric acid of diethylaminoethyl methacrylamide Salt / sodium acrylate / sodium vinyl sulfonate = 3 /
1/1 copolymer (Mw = 400,000) (J) Copolymer of quaternary ammonium salt of vinylpyridine with dimethylphosphinic acid / vinylpyrrolidone / sodium acrylate = 6/3/1 (Mw = 450,000) (K) Phosphate of diethylaminoethyl methacrylamide of (I) above as borate (L) Quaternary ammonium salt of cationized cellulose (Mw = 1,000,000) (M) 1,2-dichloroethane Polycondensate of hexamethylenetetramine phosphate (Mw = 50,000) (N) Polycondensate of ethylphosphinate of diethylenetriamine and dimer acid (Mw = 800,000) (O) Trimethylamine quaternary ammonium compound of epichlorohydrin Ring-opening polymer of phosphite (Mw = 10
(P) (P) Polycondensate of quaternary ammonium salt of tetramethylpropylenediamine with diethylphosphonic acid (Mw = 10
(Q) The phosphate of vinylpyridine of the above (G) is a sulfate (R) The thiophosphate of the diethylenetriamine of the above (H) is a nitrate (S) The dimethylamino of the above (F) (T) Ethyl phosphinate of dimethylaminoethyl methacrylate of the above (E) converted to glycolate (U) Phosphorus of ethyleneimine of the above (D) (V) quaternary ammonium salt of vinylpyridine with dimethyl sulfate / vinylpyrrolidone / sodium acrylate = 6
(Y) Na salt of homopolymer of N-1 dimethylsulfoethylacrylamide (Mw = 70,000) (Z) N of N-1 dimethylsulfoethylacrylamide
a Copolymer of salt / phosphate of dimethylaminoethyl methacrylate = 1/1 (Mw = 20,000) (AA) Phosphonate of polyethyleneimide (Mw = 6)
Ethyl phosphinate of dimethylaminoethyl methacrylate = 1/1 (Mw = 60,000) (BB) Phosphate of 3-methacryloxy-2-hydroxypropyltrimethylammonium / ethylphosphinic acid of dimethylaminoethyl methacrylate Salt = Copolymer of 2/1 (Mw = 50,000) (CC) Mixture of phosphonate of methacryldimethylaminoethyl ethoxylate (Mw = 80,000) / polyethyleneimine (Mw = 80,000) = 1/1 ( DD) Quaternary ammonium salt of cationized starch

[0088]

[Table 10]

[0089]

[Table 11]

[0090]

[Table 12]

[0091]

[Table 13]

Embodiment 89 An example of application to a blast furnace pulverized coal injection apparatus is shown below. Conditions Pulverized coal injection amount: 40 t / Hr Conveyance improver: β-naphthalenesulfonic acid formalin condensate Addition amount: 0 or 0.3 wt% Pulverized coal: Volume average particle diameter: 74 μm Water content: 1.5% Average of raw coal HGI: 45, 55, 70 FIG. 3 is a schematic view of the blast furnace pulverized coal injection apparatus used in this embodiment. In FIG. 3, 12 is a blast furnace, 13 is an inlet, 14 is an inlet pipe, 15 is a distribution tank, 16 is a valve, 17 is a pressure equalizing tank,
18 is a valve, 19 is a pulverized coal storage tank, 20 is a coal crusher,
21 is an additive spray nozzle, 22 is a coal conveyor belt conveyor,
23 indicates a coal receiving hopper and 24 indicates an air / nitrogen compressor.

The coal is put into the receiving hopper 23 and supplied to the crusher 20 by the conveyor 22. On the way, the transportability improver is spray-added from the nozzle 21. The coal is pulverized by the pulverizer 20 into pulverized coal having the above-mentioned particle size and sent to the storage tank 19. First, the valve 18 is opened while the internal pressure of the equalizing tank 17 is equal to the atmospheric pressure, and a specified amount of pulverized coal is supplied from the storage tank 19 to the equalizing tank 17. Next, the internal pressure of the equalizing tank 17 is increased until the internal pressure of the distribution tank 15 becomes the same. With the internal pressures of the tanks 15 and 17 being equal, the valve 16 opens and the pulverized coal falls by gravity. The pulverized coal is gas-transported from the distribution tank 15 to the blow-in port 13 through the blow-in pipe 14 by the blow-in air supplied from the compressor 24, and is blown into the blast furnace 12 from the blow-in port 13.

<Effect of Addition of Transportability Improver> When the pulverized coal is transported under the above conditions, the tank transfer time depending on the presence or absence of the addition of the transportability improver (the transfer of the pulverized coal from the tank 17 to the tank 15). ) And changes in pipe pressure loss (pressure loss in the blow-in pipe 14, that is, the differential pressure between the tank 15 and the blast furnace 12) were evaluated. The results are shown in FIGS. Figures 4 and 5
Among them, (A) means the case where the transportability improver was not added, (B) means the case where the transportability improver was added, and in FIG. 6, A means the upper limit value of the equipment.

When the raw coal having an average HGI of 45 was used, as shown in FIGS. 4 and 5, the pipe pressure loss and the tank transfer time were reduced, and the pulverized coal injection amount could be increased in the same apparatus. In addition, a simpler device can be used to obtain the same blowing capability. 4 and 5 are relative evaluations where the case where no transportability improver is added is set to 1.

FIG. 6 shows the change in pipe pressure loss when the average HGI of the raw coal was changed to 45, 55, and 70. Even when high HGI coal is used, the pipe pressure loss becomes less than the upper limit of the equipment by adding the transportability improver, and the type of coal used can be expanded, and inexpensive coal can be used. FIG. 6 is a relative evaluation where the case where the transportability improver is not added to pulverized coal having an average HGI of 45 is set to 1.

Example 90 An example of application to a pulverized coal-fired boiler is shown below. Additive: β-naphthalenesulfonic acid formalin condensate Additive amount: 0 or 0.3 wt% Pulverized coal: Volume average particle diameter: 74 μm Water content: 1.5% Average HGI of raw coal: 45, 55, 65, 75 In this example FIG. 7 shows a schematic diagram of the pulverized coal-fired boiler used. In FIG. 7, 25 is a boiler combustion chamber, 26 is a burner, 27 is a blowing pipe, 28 is a pulverized coal storage tank, 29 is a coal pulverizer, 30 is an additive spray nozzle, 31 is a coal conveyor belt conveyor, and 32 is coal receiving. Hopper 33 indicates an air / nitrogen compressor.

The coal is put into the receiving hopper 33 and supplied to the crusher 29 by the conveyor 31. On the way, the transportability improver is spray-added from the nozzle 30. The coal is pulverized into pulverized coal having the above-mentioned particle size by the pulverizer 29 and sent to the storage tank. Next, the air is conveyed by the blown air supplied from the compressor 33, supplied to the burner 26, and burned.

<Effect of Addition of Transportability Improver> When pulverized coal is transported under the above conditions, the pipe pressure loss due to the presence or absence of the transportability improver (pressure loss in the blowing pipe 27, ie, the tank
The change in the pressure difference between 28 and the burner 26) was evaluated. The results are shown in FIG. 8, where A means the upper limit of the equipment,
X means that the pipe was clogged. In addition, FIG. 8 is a relative evaluation with 1 when the transportability improver is not added to the pulverized coal having an average HGI of 45 of the raw coal.

When the average HGI of the raw coal was changed to 45, 55, 65, and 75, even if a high HGI coal was used, the pipe pressure loss became lower than the upper limit of the equipment even when a high HGI coal was used, and the type of coal used could be expanded.

Examples 91 to 102 and Comparative Examples 8 to 15 The same evaluations as in Examples 1 to 88 and Comparative Examples 1 to 7 were carried out using the transportability improvers shown in Tables 14 to 16. It is also shown how much the fluidity index, pressure loss and triboelectric charge increased or decreased as compared to Comparative Examples 8 to 11 in which no transportability improver was added. In other words, based on Comparative Examples 8 to 11, for each raw coal, it was shown how much the fluidity index increased and how much the pressure loss or the triboelectric charge decreased with the addition of the transportability improver ( For example, Comparative Example 5,
Examples 91, 95 and 99 are based on the values of Comparative Example 8).

[0102]

[Table 14]

[0103]

[Table 15]

[0104]

[Table 16]

[Brief description of the drawings]

FIG. 1 is a schematic diagram of an apparatus used for measuring a triboelectric charge amount.

FIG. 2 is a schematic diagram of an apparatus used for measuring pipe transport characteristics.

FIG. 3 is a schematic view of an actual blast furnace pulverized coal injection device used in Example 89.

FIG. 4 is a chart showing a result of a transfer time in Example 89.

FIG. 5 is a chart showing a result of piping pressure loss in Example 89.

FIG. 6 is a chart showing a result of piping pressure loss in Example 89.

FIG. 7 is a schematic diagram of a pulverized coal-fired boiler used in Example 90.

FIG. 8 is a chart showing a result of piping pressure loss in Example 90.

FIG. 9: Average H of raw coal when various transportability improvers are used
Chart showing the relationship between GI and triboelectric charge

[Explanation of symbols]

 1: compressed gas 2: nozzle 3: Faraday gauge 4: mesh 5: dust hole 6: electrometer 7: pulverized coal 8: table feeder 9: flow meter 10: horizontal pipe 11: cyclone 12: blast furnace 25: boiler combustion chamber 26 :burner

────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Kenichi Miyamoto 300-56 Kirei, Wakayama-shi, Wakayama (72) Inventor Takashi Matoba 1-7-9, Wakauranishi, Wakayama-shi, Wakayama 136-16 Enohara, Wakayama City, Japan (58) Field surveyed (Int.Cl. ⁶ , DB name) C21B 5/00 319 C10L 1/32 CRW

Claims (21)

(57) [Claims] An agent for improving pulverized coal transportability, comprising an organic compound having a polar group and substantially soluble in water and used for dry pulverized coal having an average HGI of 30 or more. . 2. The reduction amount of triboelectric charge of said pulverized coal when 0.3% by weight (in terms of dry coal) is added to said pulverized coal is [average HGI of raw coal] × 0.007 μC / g or more. The pulverized coal transportability improver according to claim 1. 3. The triboelectric coal has a triboelectric charge of 2.8 μC when 0.3% by weight (in terms of dry coal) is added to the pulverized coal.
/ G or less. 4. The organic compound according to claim 1, wherein the organic compound is one or more organic compounds selected from an anionic surfactant, a cationic surfactant, and an amphoteric surfactant. Pulverized coal transportability improver. 5. The pulverized coal transport improver according to claim 1, wherein the organic compound is one or more organic compounds selected from lower fatty acids and salts thereof. 6. An improved transportability of pulverized coal, wherein an organic compound having a polar group and substantially soluble in water is attached to the surface of dry pulverized coal having an average HGI of 30 or more of raw coal. Method. 7. The method according to claim 7, wherein the organic compound is added to the pulverized coal.
0.01% by weight or more and 10% by weight or less, and reduce the amount of triboelectric charge of the pulverized coal by [average HGI of raw coal] × 0.007 μC
/ G or more. 8. The method according to claim 1, wherein the organic compound is added to the pulverized coal in an amount of 0.
The method for improving pulverized coal transportability according to claim 7, wherein the amount of triboelectric charging of the pulverized coal is set to 2.8 µC / g or less by adding from 01% by weight to 10% by weight. 9. The organic compound is one or more organic compounds selected from anionic surfactants, cationic surfactants and amphoteric surfactants.
The method for improving the transportability of pulverized coal according to any one of the above. 10. The method for improving the transportability of pulverized coal according to claim 6, wherein the organic compound is one or more organic compounds selected from lower fatty acids or salts thereof. 11. Dry pulverized coal having an average HGI of 30 or more of raw coal, to which an organic compound having a polar group and substantially soluble in water is attached. 12. The organic compound adheres in an amount of 0.01% by weight or more and 10% by weight or less, and the amount of decrease in triboelectric charge is [average H of raw coal].
12. The pulverized coal according to claim 11, which is at least GI] × 0.007 μC / g. 13. The pulverized coal according to claim 12, wherein the organic compound adheres in an amount of 0.01% by weight or more and 10% by weight or less, and has a triboelectric charge of 2.8 μC / g or less. 14. The fine powder according to claim 11, wherein the organic compound is one or more organic compounds selected from an anionic surfactant, a cationic surfactant and an amphoteric surfactant. Charcoal. 15. The pulverized coal according to claim 11, wherein the organic compound is one or more organic compounds selected from lower fatty acids and salts thereof. 16. A metallurgical furnace characterized in that an organic compound having a polar group and substantially soluble in water adheres thereto, and dry pulverized coal having an average HGI of raw coal of 30 or more is blown from a blow hole. How to operate the combustion furnace. 17. The method for operating a metallurgical furnace or a combustion furnace according to claim 16, wherein the pulverized coal to which the organic compound is attached in an amount of 0.01% by weight or more and 10% by weight or less is blown from a blowing port. 18. The organic compound adheres in an amount of 0.01% by weight or more and 10% by weight or less, and the amount of triboelectric charge decreases by [average H of raw coal].
18. The method for operating a metallurgical furnace or a combustion furnace according to claim 16, wherein pulverized coal having GI] × 0.007 μC / g or more is blown from a blowing port. 19. The metallurgy according to claim 18, wherein the pulverized coal having the organic compound attached thereto in an amount of 0.01% by weight or more and 10% by weight or less and having a triboelectric charge of 2.8 μC / g or less is blown from a blowing port. Furnace or combustion furnace operating method. 20. The organic compound according to claim 16, wherein the organic compound is one or more organic compounds selected from an anionic surfactant, a cationic surfactant and an amphoteric surfactant. Metallurgical furnace or combustion furnace operation method. 21. The method for operating a metallurgical furnace or a combustion furnace according to claim 16, wherein the organic compound is one or more organic compounds selected from lower fatty acids or salts thereof.