A mine fireproof grouting material prepared using coal gasification ash

Abstract

The present invention discloses a mine fireproof grouting material prepared by using coal gasification ash, which comprises the following components by weight: cementitious material: 100 parts; filler: 0-200 parts; additive: 0.1-3.0 parts; water: 40-150 parts; wherein the cementitious material is fly ash from coal gasification; the filler is coarse coal gasification slag and / or fine coal gasification slag; the additive is one or more of a water reducer, a retarder, an activator and a thixotropic agent. The use of coal gasification ash as the main raw material to prepare the mine fireproof grouting material can not only solve the solid waste treatment problem of coal gasification ash, but also solve the problem of fireproof grouting in mines. At the same time, the prepared fireproof grouting material has a very low cost and a certain compressive strength, and can achieve multiple functions such as fireproof grouting, backfilling of goaf, reinforcement of bedrock of goaf, and prevention of goaf collapse.

Description

Technical Field

[0001] The invention belongs to the field of comprehensive utilization of coal chemical solid waste and also belongs to the field of coal mine safety protection technology, and specifically relates to a mine fireproof grouting material prepared by using coal gasification ash. Background Art

[0002] In 2018, my country's coal consumption was 3.9 billion tons, accounting for about 59% of energy consumption. Among them, the power industry consumed about 2.1 billion tons of coal, the steel industry consumed about 620 million tons of coal, the building materials industry consumed about 500 million tons of coal, the chemical industry consumed about 280 million tons of coal, and other industries consumed about 60 million tons less coal. The coal consumption process produces about 500 million tons of various types of ash and coal slag (calculated on a dry basis). In addition to the resource utilization of some ash and slag from coal-fired boilers in coastal and economically developed areas, coal slag emissions occupy a large amount of land resources.

[0003] Coal gasification ash is a kind of solid waste in the coal chemical industry. It is the solid residue produced when coal powder is converted into synthesis gas in a high-temperature gasifier. It is generally divided into coarse slag and fine slag. Fly ash is also produced under some process routes. The coarse slag, fine slag and fly ash produced by the gasifier can be collectively referred to as coal gasification ash. my country produces tens of millions of tons of coal gasification ash every year. Coal gasification ash has high residual carbon content, high moisture content, loose and porous structure, low active component content, water-soluble ions, easy to form dust and other reasons. It has not been able to be applied on a large scale, especially the resource utilization of entrained-bed coal gasification ash is even less, and it is mainly placed in slag yards for storage, which not only seriously pollutes the environment, but also causes a waste of land resources.

[0004] The coal left in the tunnels of the coal mine goaf and the unmined coal will slowly oxidize and heat up, which will cause spontaneous combustion. Therefore, fire prevention measures such as grouting are needed in the goaf to isolate the contact between coal and air and prevent coal oxidation and spontaneous combustion. In the paper "Application Research on Technical Solutions for Underground Fire Prevention in Coal Mines" (Energy and Energy Conservation, Issue 7, 2021) published by Pan Enbao of Fuxin Mining (Group) Co., Ltd., fireproof grouting was carried out in the goaf of the mine using a fireproof grouting material prepared with fly ash, water and solidified mixed materials; in the paper "Comparative Optimization Study on Highly Absorbent Materials for Grouting in Coal Mines" (Coal Science and Technology, 2022, Vol. 43, Issue 3), Wang Mian and others of Anhui Jinding Safety Technology Co., Ltd. published a paper on "Comparative Optimization Study on Highly Absorbent Materials for Grouting in Coal Mines" (Coal Science and Technology, 2022, Vol. 43, Issue 3), high-absorbent materials were used to modify yellow mud slurry for underground fireproof grouting in coal mines when the goaf has a large inclination angle or the gap in the caving zone is large.

[0005] There are two main preparation processes for fireproof grouting materials in mines at present. One is to mix cement or fly ash discharged from coal-fired boilers with water to form a slurry material for preparation, and the other is to mix loess with water to form yellow mud slurry for grouting. The fireproof grouting material prepared by mixing cement or fly ash into a slurry material has better slurry performance. Although the fly ash used in it is also a solid waste, fly ash has been widely used in various concrete engineering constructions and has achieved a lot of research results and application experience. Fly ash has become a commonly used concrete / mortar cementitious material, resulting in a relatively high price of fly ash and a high overall material cost; the use of loess and water to prepare fireproof grouting materials will use a large amount of surface soil, damage the environment, and the prepared grouting material has no strength. The water content in the loess slurry accounts for more than 70%, which can only play a fireproof role. It is not helpful for the collapse control of the goaf. There is a risk of oxidation of coal that is not isolated from the air after water loss and causes fire. Summary of the invention

[0006] In view of the above problems, the present invention adopts coal gasification ash as the main raw material to prepare mine fireproof grouting material, which can not only solve the solid waste treatment problem of coal gasification ash, but also solve the fireproof grouting problem in mines. At the same time, the prepared fireproof grouting material has a very low cost and a certain compressive strength, and can achieve the dual functions of fireproof grouting and goaf backfilling.

[0007] To achieve its purpose, the present invention adopts the following technical solutions:

[0008] In one aspect of the present invention, there is provided a mine (e.g., coal mine) fireproof grouting material prepared using coal gasification ash, which comprises the following components by weight:

[0009] Cementitious material: 100 parts;

[0010] Filler: 0-200 parts;

[0011] Additives: 0.1-3.0 parts;

[0012] Water: 40-150 parts;

[0013] Wherein, the cementitious material is fly ash from coal gasification; the filler is coarse coal gasification slag and / or fine coal gasification slag; and the additive is one or more of a water reducer, a retarder, an activator and a thixotropic agent.

[0014] The mine fireproof grouting material prepared using coal gasification ash as described in the present invention includes, by weight: 100 parts of cementitious material; 0-200 parts of filler, for example, 25 parts, 50 parts, 75 parts, 100 parts, 125 parts, 150 parts, 175 parts, etc.; 0.1-3.0 parts of additives, for example, 0.25 parts, 0.5 parts, 0.75 parts, 1.0 parts, 1.25 parts, 1.5 parts, 1.75 parts, 2.0 parts, 2.25 parts, 2.5 parts, 2.75 parts, etc.; and 40-150 parts of water, for example, 50 parts, 75 parts, 100 parts, 125 parts, etc.

[0015] In the above ratio, the amount of filler added can be 0. The fireproof grouting material prepared in this case has greater fluidity and strength, but cannot handle the coarse slag and fine slag produced by the coal gasification device. In the above ratio, the filler can be a single coarse slag, a single fine slag, or a mixture of coarse slag and fine slag. It can be added according to the ratio of coarse slag and fine slag produced by the coal gasification device, or it can be added according to the performance requirements of the fireproof grouting material. In general, the coarse slag has larger particles, lower carbon content, and lower water demand. The prepared fireproof grouting liquid has greater fluidity and higher strength. The solid content of the slurry is higher, the viscosity is greater, and the requirements for pressure grouting equipment are higher; the fine slag has finer particles, higher carbon content, and higher water demand. The prepared fireproof grouting liquid has average fluidity, lower strength, and lower solid content of the slurry. However, because they are all fine powders, the viscosity of the slurry is lower, and the requirements for pressure grouting equipment are lower.

[0016] In a specific embodiment of the present invention, pulverized coal gasification fly ash refers to fly ash produced by a coal gasification process device, also known as gasifier fly ash, or fly ash associated with entrained flow pulverized coal gasification. In a preferred embodiment of the present invention, the pulverized coal gasification fly ash is dry fine solid particles collected by a filter in a pressurized entrained flow dry coal powder gasification device, and particles with a particle size of less than 100 μm account for more than 90%; preferably, the chemical composition of the pulverized coal gasification fly ash includes: 45wt% to 55wt% SiO2, 15wt% to 25wt% Al2O3, 5wt% to 15wt% Fe2O3, and 10wt% to 20wt% CaO.

[0017] In a specific embodiment of the present invention, the coal gasification slag refers to the slag produced by the coal gasification process device, also known as the gasification furnace slag. In a preferred embodiment of the present invention, the coal gasification slag is wet coarse solid particles collected by a slag remover in a pressurized fluidized bed dry coal powder gasification or a fluidized bed water-coal slurry pressurized gasification device, and particles with a particle size greater than 0.5 mm account for more than 60%; the coal gasification slag is characterized in that the dry solid slag contains 4.5wt% to 26wt% residual carbon; preferably, the chemical composition of the coal gasification slag excluding residual carbon and moisture comprises: 35wt% to 45wt% SiO2, 15wt% to 25wt% Al2O3, 10wt% to 20wt% Fe2O3, and 10wt% to 20wt% CaO; the coal gasification slag contains MgO, Na2O, K2O, TiO, MnO, SO3 and other oxides in an amount of about 4-12wt%, for example, about 6wt%, about 7wt%, about 8wt%, about 9wt%, about 10wt%, or about 11wt%. The elements in the crude slag of coal gasification exist in the form of quartz, mullite, calcite, aluminosilicate, etc., or in the form of amorphous oxides such as glass.

[0018] In a specific embodiment of the present invention, coal gasification fine slag refers to fine slag produced by a coal gasification process device, also known as gasifier fine slag. In a preferred embodiment of the present invention, the coal gasification fine slag is moist fine solid particles collected by a sedimentation tank in a pressurized fluidized bed dry coal powder gasification or a fluidized bed water-coal slurry pressurized gasification device, and particles with a particle size of less than 0.5 mm account for more than 90%; the coal gasification fine slag is characterized in that it contains 10-42wt% residual carbon in the solid fine slag on a dry basis; preferably, the chemical composition of the coal gasification fine slag excluding residual carbon and moisture comprises: 40wt% to 50wt% SiO2, 15wt% to 25wt% Al2O3, 10wt% to 20wt% Fe2O3, and 5wt% to 15wt% CaO; the coal gasification fine slag contains MgO, Na2O, K2O, TiO, MnO, SO3 and other oxides in an amount of about 6-12wt%, for example, about 7wt%, about 8wt%, about 9wt%, about 10wt%, or about 11wt%. The elements in the coal gasification fine slag exist in the form of quartz, mullite, calcite, aluminosilicate, etc., or in the form of amorphous oxides such as glass.

[0019] In a specific embodiment of the present invention, the water reducer is a powder water reducer or a liquid water reducer, preferably one or more selected from polycarboxylic acid water reducer, naphthalene water reducer and melamine water reducer.

[0020] In a specific embodiment of the present invention, the retarder is selected from one or more of sodium gluconate, tartaric acid and citric acid.

[0021] In a specific embodiment of the present invention, the activator is selected from one or more of sodium sulfate, sodium carbonate, sodium silicate, sodium hydroxide and triethanolamine.

[0022] In a specific embodiment of the present invention, the thixotropic agent is selected from one or more of cellulose ether, starch ether, magnesium aluminum silicate and biological glue (such as Brunei glue).

[0023] In a specific embodiment of the present invention, the water is groundwater, tap water or industrial wastewater. The industrial wastewater can be treated to a certain extent as needed, and the specific treatment method is well known to those skilled in the art.

[0024] The fireproof grouting material according to the present invention has a certain fluidity, and can be transported to the goaf of the mine by self-weight grouting or pressure grouting. After a period of solidification, the grouting material will harden and have a certain compressive strength, which can play multiple roles such as fireproof grouting, goaf backfilling, reinforcement of bedrock in goaf, and prevention of goaf collapse. The heavy metal leaching performance of the solidified slurry meets the index requirements of Class I general industrial solid waste in GB18599-2020 "General Industrial Solid Waste Storage and Landfill Pollution Control Standards", and underground grouting construction can be carried out directly without environmental protection problems.

[0025] In another aspect of the present invention, it relates to a method for preparing the above-mentioned mine fireproof grouting material prepared by using coal gasification ash, which comprises:

[0026] Adding the gelling material, optional fillers, additives and water into a mixer at the same time, and stirring to obtain the mine fireproof grouting material, preferably the stirring speed is 60-240r / min, and the stirring time is 1-3min; or

[0027] First, the cementitious material, water and additives are stirred at high speed to prepare a cementitious slurry, and then the cementitious slurry and filler are mixed with a slow mixer or a continuous mixer to obtain the mine fireproof grouting material; preferably, the stirring speed of the high-speed stirring is 200-400r / min, and the stirring time is 1-2min; the stirring speed of the slow mixer or the continuous mixer is 60-120r / min, and the stirring time is 2-3min.

[0028] Compared with the prior art, the beneficial effects of the present invention are mainly reflected in the following aspects: using coal gasification ash as the main raw material to prepare mine fireproof grouting materials can not only solve the solid waste treatment problem of coal gasification ash, but also solve the fireproof grouting problem in mines. At the same time, the prepared fireproof grouting material has a very low cost and a certain compressive strength, and can achieve multiple functions such as fireproof grouting, backfilling of goaf areas, reinforcement of bedrock of goaf areas, and prevention of goaf collapse. DETAILED DESCRIPTION

[0029] The present invention is further described below in conjunction with embodiments, but the present invention is not limited to the listed embodiments, and should also include equivalent improvements and modifications of the technical solutions defined in the claims attached to the present application.

[0030] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0031] raw material

[0032] Pulverized coal gasification fly ash: dry fine solid particles collected by the filter in the pressurized entrained bed dry pulverized coal gasification device of Ordos Coal to Oil Branch of Shenhua Coal to Oil Chemical Co., Ltd., with particles with a particle size of less than 100μm accounting for more than 90%; chemical composition (wt%) is as follows:

[0033] Table 1 Chemical composition of fly ash from pressurized entrained flow dry pulverized coal gasification device

[0034] <![CDATA[SiO2]]> <![CDATA[Al2O3]]> <![CDATA[Fe2O3]]> CaO other total 48.1 22.0 7.2 12.1 10.6 100

[0035] Coal gasification crude slag: wet coarse solid particles collected by the slag remover in the pressurized entrained bed dry coal powder gasification of Ordos Coal to Oil Branch of Shenhua Coal to Oil Chemical Co., Ltd. or the fluidized bed water-coal slurry pressurized gasification device of Guoneng Baotou Coal Chemical Co., Ltd., with particles with a particle size greater than 0.5 mm accounting for more than 60%, the solid crude slag of the pressurized entrained bed dry coal powder gasification device contains 4.9wt% residual carbon on a dry basis, and the residual carbon content of the crude slag discharged from the water-coal slurry pressurized gasification device is 22wt% on a dry basis; the chemical compositions (wt%) of the crude slag of the two gasification devices used in the embodiment, excluding residual carbon and moisture, are as follows:

[0036] Table 2 Chemical composition of coarse slag from dry pulverized coal gasification and water-coal slurry gasification units

[0037]

[0038] Coal gasification fine slag: wet fine solid particles discharged from the settling tank of the pressurized entrained bed dry coal powder gasification device of the Ordos Coal-to-Oil Branch of Shenhua Coal-to-Oil Chemical Co., Ltd. or the fluidized bed water-coal slurry pressurized gasification device of Guoneng Baotou Coal Chemical Co., Ltd. to the horizontal screw machine for preliminary dehydration, and particles with a particle size of less than 0.5mm account for more than 90%. The solid fine slag on a dry basis of the pressurized entrained bed dry coal powder gasification device contains 23.9wt% of residual carbon, and the solid fine slag on a dry basis of the water-coal slurry gasification device contains 39.9wt% of residual carbon; the chemical compositions (wt%) of the two types of gasification fine slag used in the examples, excluding residual carbon and moisture, are as follows:

[0039] Table 3 Chemical composition of fine slag from dry coal pulverization gasification and water-coal slurry gasification

[0040]

[0041] Liquid polycarboxylate water reducer: commercially available, solid content between 10-40%;

[0042] Powdered polycarboxylate water reducer: commercially available, brand PC100;

[0043] Liquid naphthalene water reducer: commercially available, the active ingredient is naphthalene sulfonate formaldehyde condensate;

[0044] Sodium gluconate: industrial grade, active ingredient content more than 95%;

[0045] Sodium carbonate: industrial grade, with an active ingredient content of more than 95%;

[0046] Tartaric acid: industrial grade, active ingredient content more than 95%;

[0047] Sodium sulfate: industrial grade, active ingredient content more than 95%;

[0048] Brunei gum: industrial grade, with an active ingredient content of more than 95%;

[0049] Unless otherwise specified, other raw materials mentioned herein are conventional commercially available raw materials.

[0050] Test Method

[0051] Fluidity and water seepage rate: tested in accordance with GB / T50448-2015 "Technical Specifications for Application of Cement-based Grouting Materials";

[0052] Compressive strength: Tested in accordance with JGJ / T70-2009 "Standard for Test Methods for Basic Properties of Building Mortar".

[0053] Example

[0054] Parts hereinafter refer to parts by weight.

[0055] Example 1 :

[0056] This embodiment provides a mine fireproof grouting material prepared using coal gasification ash, and its composition and proportion are as follows:

[0057] Pulverized coal gasification fly ash: 100 parts;

[0058] Dry pulverized coal gasification crude slag: 150 parts;

[0059] Liquid polycarboxylate water reducer: 0.2 parts;

[0060] Water: 60 parts;

[0061] The above components are fed into a horizontal high-speed mixer (the same below) according to the proportion, and stirred for 1 minute (stirring speed is 240r / min) to prepare a fireproof grouting material with high fluidity. After testing, the initial fluidity is 310mm, the fluidity after 30 minutes is 260mm, and the water bleeding rate is 1.2%. After testing, the compressive strength at 3d, 7d, and 28d (d means day, the same below) is 0.2MPa, 2.1MPa, and 4.5MPa respectively.

[0062] The above-mentioned fireproof grouting material is injected into the goaf of the coal mine using an industrial filling pump. It can not only isolate the air and prevent the spontaneous combustion of coal, but also have the required strength after the slurry hardens, which can play the role of backfilling the goaf and preventing surface collapse.

[0063] Example 2 :

[0064] This embodiment provides a mine fireproof grouting material prepared using coal gasification ash, and its composition and proportion are as follows:

[0065] Pulverized coal gasification fly ash: 100 parts;

[0066] Dry pulverized coal gasification crude slag: 150 parts;

[0067] Liquid naphthalene water reducer: 0.5 parts;

[0068] Sodium gluconate: 0.03 parts;

[0069] Water: 60 parts;

[0070] The preparation method is the same as that of Example 1. The difference from Example 1 is that sodium gluconate is added as a retarder in this example, so that the slurry can maintain fluidity for a longer time. The initial fluidity is 310 mm, and the fluidity is 290 mm after 30 minutes, which is more conducive to long-distance grouting construction.

[0071] Example 3 :

[0072] This embodiment provides a mine fireproof grouting material prepared using coal gasification ash, and its composition and proportion are as follows:

[0073] Pulverized coal gasification fly ash: 100 parts;

[0074] Coal-water slurry gasification crude slag: 150 parts;

[0075] Liquid polycarboxylate water reducer: 0.2 parts;

[0076] Sodium carbonate: 1 part;

[0077] Water: 60 parts;

[0078] The preparation method is the same as that of Example 1. The difference from Example 1 is that sodium carbonate is added as an activator in this example, so that the early strength of the slurry is higher, which is suitable for working conditions with high requirements for the early strength of fireproof grouting materials. After testing, the 3d, 7d, and 28d compressive strengths are 1.2MPa, 3.4MPa, and 4.7MPa, respectively.

[0079] Example 4 :

[0080] This embodiment provides a mine fireproof grouting material prepared using coal gasification ash, and its composition and proportion are as follows:

[0081] Pulverized coal gasification fly ash: 100 parts;

[0082] Dry pulverized coal gasification crude slag: 120 parts;

[0083] Powdered polycarboxylate water reducer: 0.1 part;

[0084] Tartaric acid: 0.1 part;

[0085] Sodium sulfate: 2 parts;

[0086] Brunei gum: 0.02 parts;

[0087] Water: 50 parts;

[0088] The preparation method is the same as that of Example 1. The difference from Example 1 is that sodium sulfate is added as an activator, tartaric acid is added as a retarder, and Brunei gum is added as a thixotropic agent in this embodiment, so that the prepared fire-proof grouting material has the advantages of long pumping time, high early strength, and no water seepage from the slurry.

[0089] Example 5 :

[0090] This embodiment provides a mine fireproof grouting material prepared using coal gasification ash, and its composition and proportion are as follows:

[0091] Pulverized coal gasification fly ash: 100 parts;

[0092] Coal-water slurry gasification fine slag: 50 parts;

[0093] Liquid polycarboxylate water reducer: 0.5 parts;

[0094] Water: 130 parts;

[0095] The above components are fed into a stirring device in proportion and stirred for 3 minutes (stirring speed is 120r / min) to prepare a fireproof grouting material. Since the coal gasification fine slag has a high carbon content and a large water absorption capacity, the fireproof grouting material prepared by this method has a low fluidity, but since the solid particles are all fine powders, this fireproof grouting material has low requirements for pressure pumping equipment and can be transported over long distances using a centrifugal pump.

[0096] The fireproof grouting liquid prepared above was tested and the compressive strengths at 3d, 7d and 28d were 0MPa, 0.2MPa and 0.4MPa respectively.

[0097] Example 6 :

[0098] This embodiment provides a mine fireproof grouting material prepared using coal gasification ash, and its composition and proportion are as follows:

[0099] Pulverized coal gasification fly ash: 100 parts;

[0100] Dry pulverized coal gasification fine slag: 20 parts;

[0101] Dry pulverized coal gasification crude slag: 100 parts;

[0102] Liquid polycarboxylate water reducer: 0.5 parts;

[0103] Sodium sulfate: 0.5 parts;

[0104] Water: 80 parts;

[0105] The above components are fed into a stirring device according to a proportion, and stirred for 3 minutes (stirring speed is 100r / min) to prepare a fireproof grouting material. This embodiment uses fly ash from coal gasification, fine coal gasification slag and coarse coal gasification slag at the same time, and treats three kinds of solid waste at the same time.

[0106] The specific performance parameters of the fireproof grouting materials obtained in Examples 1-6 are shown in the following table:

[0107] Table 4

[0108]

[0109] Although the present invention has been described in detail for the purpose of illustration in the foregoing text, it should be understood that these detailed descriptions are only for illustration and can be modified by those skilled in the art without departing from the spirit and scope of the present invention. The present invention is limited only by the claims.

Claims

1. A mine fireproof grouting material prepared using coal gasification ash, which consists of the following components by weight: Cementitious material: 100 parts; Filler: 25-200 parts; Additives: 0.1-3.0 parts; Water: 40-150 parts; Wherein, the cementitious material is fly ash from coal gasification; the filler is coarse coal gasification slag or a combination of coarse coal gasification slag and fine coal gasification slag; the additive is one or more of a water reducer, a retarder, an activator and a thixotropic agent; The chemical composition of the pulverized coal gasification fly ash includes: 45wt% to 55wt% SiO2, 15wt% to 25wt% Al2O3, 5wt% to 15wt% Fe2O3, and 10wt% to 20wt% CaO.

2. The mine fireproof grouting material prepared by using coal gasification ash according to claim 1, wherein: The pulverized coal gasification fly ash is dry fine solid particles collected by a filter in a pressurized fluidized bed dry pulverized coal gasification device, and particles with a particle size of less than 100 μm account for more than 90%.

3. The mine fireproof grouting material prepared by using coal gasification ash according to claim 1, wherein: The coal gasification coarse slag is wet coarse solid particles collected by a slag remover in a pressurized fluidized bed dry coal powder gasification or fluidized bed water-coal slurry pressurized gasification device, and particles with a particle size greater than 0.5 mm account for more than 60%.

4. The mine fireproof grouting material prepared by using coal gasification ash according to claim 3, wherein: The chemical composition of the coal gasification crude slag excluding residual carbon and moisture includes: 35wt% to 45wt% SiO2, 15wt% to 25wt% Al2O3, 10wt% to 20wt% Fe2O3, and 10wt% to 20wt% CaO.

5. The mine fireproof grouting material prepared by using coal gasification ash according to claim 1, wherein: The coal gasification fine slag is moist fine solid particles collected by a settling tank in a pressurized fluidized bed dry coal powder gasification or fluidized bed water-coal slurry pressurized gasification device, and particles with a particle size of less than 0.5 mm account for more than 90%.

6. The mine fireproof grouting material prepared by using coal gasification ash according to claim 5, wherein: The chemical composition of the coal gasification fine slag excluding residual carbon and moisture includes: 40wt% to 50wt% SiO2, 15wt% to 25wt% Al2O3, 10wt% to 20wt% Fe2O3, and 5wt% to 15wt% CaO.

7. The mine fireproof grouting material prepared by using coal gasification ash according to any one of claims 1 to 6, wherein: The water reducing agent is a powder water reducing agent or a liquid water reducing agent.

8. The mine fireproof grouting material prepared by using coal gasification ash according to claim 7, wherein: The water reducer is selected from one or more of polycarboxylic acid water reducer, naphthalene water reducer and melamine water reducer.

9. The mine fireproof grouting material prepared by using coal gasification ash according to any one of claims 1 to 6, wherein: The retarder is selected from one or more of sodium gluconate, tartaric acid and citric acid.

10. The mine fireproof grouting material prepared by using coal gasification ash according to any one of claims 1 to 6, wherein: The activator is selected from one or more of sodium sulfate, sodium carbonate, sodium silicate, sodium hydroxide and triethanolamine.

11. The mine fireproof grouting material prepared by using coal gasification ash according to any one of claims 1 to 6, wherein: The thixotropic agent is selected from one or more of cellulose ether, starch ether, magnesium aluminum silicate and bio-gum.

12. The mine fireproof grouting material prepared by using coal gasification ash according to any one of claims 1 to 6, wherein: The water is groundwater, tap water or industrial wastewater.

13. A method for preparing a mine fireproof grouting material prepared by using coal gasification ash as claimed in any one of claims 1 to 12, comprising: Adding the gelling material, filler, additive and water into a mixer at the same time, and stirring to obtain the mine fireproof grouting material; or Firstly, the gelling material, water and additives are stirred at high speed to prepare a gelling slurry, and then the gelling slurry and filler are mixed by a slow mixer or a continuous mixer to obtain the mine fireproof grouting material.

14. The preparation method according to claim 13, comprising: Adding the gelling material, filler, additive and water into a mixer at the same time, stirring at a stirring speed of 60-240 r / min for 1-3 min to obtain the mine fireproof grouting material; or First, the cementitious material, water and additives are stirred at high speed to prepare a cementitious slurry, and then the cementitious slurry and filler are mixed with a slow mixer or a continuous mixer to obtain the mine fireproof grouting material, wherein the stirring speed of the high-speed stirring is 200-400r / min, and the stirring time is 1-2min; the stirring speed of the slow mixer or the continuous mixer is 60-120r / min, and the stirring time is 2-3min.

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