Flexible mining low-temperature spraying material adapting to complex geological conditions and preparation method thereof

Abstract

The invention belongs to the technical field of spraying materials, and particularly discloses a flexible mining low-temperature spraying material adapting to complex geological conditions and a preparation method thereof.The spraying material is prepared from, by weight, 3-6 parts of nano silicon dioxide, 8-15 parts of 4, 4-diphenylmethane diisocyanate, 4-8 parts of polytetrahydrofuran, 1-3 parts of propylene glycol and 20-30 parts of epoxy resin. The coating is prepared from the following components in parts by weight: 15-30 parts of organic silicon modified acrylate emulsion, 1-2 parts of alkyl siloxane, 1-2 parts of tetrahydroxymethyl phosphonium sulfate, 2-6 parts of plasticizer, 1-3 parts of dispersing agent, 12-25 parts of filler, 2-4 parts of defoaming agent and 2-6 parts of curing agent. According to the flexible mining low-temperature spraying material adapting to the complex geological conditions and the preparation method of the flexible mining low-temperature spraying material, the flexible mining low-temperature spraying material has good flexibility, cohesiveness and low-temperature resistance, facilities such as mine roadways can be effectively protected under the complex geological conditions and the low-temperature environment, the preparation method is simple, and the cost is low.

Description

Technical Field

[0001] The present invention relates to the technical field of spraying materials, in particular to a flexible low-temperature spraying material for mines adapted to complex geological conditions and a preparation method thereof. Background Art

[0002] Underground mining in China is facing problems that need to be solved urgently, such as complex geological conditions, severe mining conditions, rockfalls, geological collapses, and large occupation of land by slag.

[0003] A coal mine is an area where humans extract coal resources in coal-rich mining areas, generally divided into underground coal mines and surface coal mines. When carrying out mine mining, numerous risks are faced, such as the mining environment, geological collapses. Due to the deliquescence and weathering of the surrounding rock mass in the coal mine underground, coal and rock masses crack, groundwater leaks, air leaks, and gas leaks occur. Spraying slurry is a coating method that uses a spray gun or a disc atomizer to disperse into uniform and fine droplets by means of pressure or centrifugal force and apply them to the surface of the object to be coated. At present, in order to avoid collapses and gas leaks inside the mine tunnel, a sealing coating needs to be sprayed on the surface of the surrounding rock, which can seal the exposed surface of the surrounding rock and improve the tightness and durability.

[0004] Traditional mining spraying materials have many deficiencies in dealing with complex situations in the mine. For example, rigid materials are difficult to adapt to the deformation of rocks and are prone to problems such as cracking and peeling, resulting in a decline in the protection effect; while some existing flexible materials will deteriorate in performance at low temperatures, such as reduced flexibility and weakened adhesion, and cannot meet the usage requirements of mines in cold regions or low-temperature working environments. In addition, the existing spraying materials often have complex processes during preparation, which is not conducive to large-scale popularization and application. Therefore, it is of great practical significance to develop a flexible low-temperature spraying material for mines that can adapt to complex geological conditions, maintain good performance at low temperatures, and has a simple preparation method. Summary of the Invention

[0005] The purpose of the present invention is to provide a flexible low-temperature spraying material for mines adapted to complex geological conditions and a preparation method thereof. This material has good flexibility, adhesiveness, and low-temperature resistance, can effectively protect facilities such as mine roadways under complex geological conditions and low-temperature environments, and has a simple preparation method and low cost.

[0006] To achieve the above object, the present invention provides a flexible low-temperature spraying material for mines adapted to complex geological conditions, comprising raw materials composed of the following parts by weight: 3-6 parts of nano-silica, 8-15 parts of 4,4-diphenylmethane diisocyanate, 4-8 parts of polytetrahydrofuran, 1-3 parts of propylene glycol, 20-30 parts of epoxy resin, 15-30 parts of organosilicon-modified acrylate emulsion, 1-2 parts of alkylsiloxane, 1-2 parts of tetrahydroxymethylphosphonium sulfate, 2-6 parts of plasticizer, 1-3 parts of dispersant, 12-25 parts of filler, 2-4 parts of defoamer, and 2-6 parts of curing agent.

[0007] Preferably, the alkylsiloxane is one of methyltrimethoxysilane and methyltriethoxysilane.

[0008] Preferably, the filler includes quartz sand, talcum powder, and mica powder. The particle size of the quartz sand is 0.5-1.5 mm, the particle size of the talcum powder is 0.1-0.5 mm, and the particle size of the mica powder is 0.01-0.1 mm. The volume ratio of quartz sand: talcum powder: mica powder is 3:4.5:2.5.

[0009] Preferably, the dispersant is at least one of polyacrylate and sodium hexametaphosphate.

[0010] Preferably, the particle size of the nano-silica is 5-10 μm.

[0011] Preferably, the plasticizer is one or more of dibutyl phthalate, dioctyl adipate, and epoxy fatty acid ester.

[0012] Preferably, the defoamer is at least one of polydimethylsiloxane and polyoxyethylene polyoxypropylene ether.

[0013] Preferably, the curing agent is at least one of ethylenediamine, phthalic anhydride, and resorcinol.

[0014] The present invention also provides a preparation method of the flexible low-temperature spraying material for mines adapted to complex geological conditions, comprising the following steps:

[0015] Step 1: Add the vacuum-dehydrated polytetrahydrofuran into a flask, heat it up to 45-60 °C, add 4,4-diphenylmethane diisocyanate and nano-silica, and mix them evenly. Stir and react at 55-70 °C for 2 h to obtain a polyurethane prepolymer;

[0016] Step 2: Weigh the alkylsiloxane and tetrahydroxymethylphosphonium sulfate, add them into an autoclave, and under stirring conditions, heat up to 110-150 °C and stir for reaction; after the autoclave stirs and reacts for 2-4 hours, stop heating and continue to stir until the temperature drops to room temperature; open the autoclave, filter and separate the obtained solid-liquid, wash the filter cake with petroleum ether until clean, dry and crush it to obtain a reaction auxiliary agent;

[0017] Step 3: Add the silicone-modified acrylate emulsion into the reaction kettle, start stirring, and the stirring speed is 300 - 500 r / min;

[0018] Step 4: Slowly add the polyurethane prepolymer from Step 1 into the reaction kettle in Step 3, continue stirring for 30 - 60 minutes to make it evenly dispersed in the emulsion, and then add epoxy resin and stir evenly;

[0019] Step 5: Sequentially add propylene glycol, plasticizer, reaction assistant, dispersant, and defoamer, and stir for 20 - 40 min to make them fully mixed;

[0020] Step 6: Add filler and stir for 15 - 30 min to obtain a uniform mixed material;

[0021] Step 7: Before use, add the curing agent into the mixed material, stir evenly, and then spraying construction can be carried out.

[0022] The advantages and beneficial effects of the present invention adopting the above flexible mining low-temperature spraying material adapted to complex geological conditions and its preparation method are as follows:

[0023] 1. The silicone-modified acrylate emulsion of the present invention endows the material with excellent flexibility, can adapt to the deformation of rocks, and is not easy to crack or fall off.

[0024] 2. By adding nano-silica and propylene glycol, the present invention effectively improves the performance stability of the material in low-temperature environments. It can still maintain good flexibility and adhesiveness in a low-temperature environment of -20°C. Propylene glycol reduces the freezing point and improves low-temperature fluidity and stability.

[0025] 3. Due to the synergistic effect between the curing agent and each component of the present invention, it has a strong adhesive force to the surfaces such as mine roadways and can firmly adhere.

[0026] 4. The addition of alkyl siloxane and phosphonium tetramethylol sulfate in the present invention makes the spraying material have good flame retardant performance and can effectively prevent the occurrence of fire accidents.

[0027] Next, through examples, the technical solutions of the present invention will be further described in detail. Specific Embodiments

[0028] The following further illustrates the technical solutions of the present invention through examples.

[0029] Unless otherwise defined, the technical terms or scientific terms used in the present invention shall have the ordinary meanings understood by those of ordinary skill in the field to which the present invention belongs.

[0030] Unless otherwise defined, the reagents, equipment and other materials used in the present invention are all obtained from conventional commercial sources.

[0031] Example 1

[0032] A flexible low-temperature spraying material for mines adapted to complex geological conditions, comprising raw materials composed of the following parts by weight: 3 parts of nano-silica, 10 parts of 4,4-diphenylmethane diisocyanate, 4 parts of polytetrahydrofuran, 2 parts of propylene glycol, 25 parts of epoxy resin, 20 parts of organosilicon-modified acrylate emulsion, 2 parts of alkylsiloxane, 2 parts of tetrahydroxymethylphosphonium sulfate, 3 parts of plasticizer, 2 parts of dispersant, 15 parts of filler, 3 parts of defoamer, and 4 parts of curing agent.

[0033] The alkylsiloxane is methyltrimethoxysilane.

[0034] The filler includes quartz sand, talcum powder, and mica powder. The particle size of the quartz sand is 0.5 mm, the particle size of the talcum powder is 0.2 mm, and the particle size of the mica powder is 0.05 mm. The volume ratio of quartz sand: talcum powder: mica powder is 3:4.5:2.5.

[0035] The dispersant is polyacrylate.

[0036] The particle size of the nano-silica is 5 μm.

[0037] The plasticizer is dibutyl phthalate and dioctyl adipate.

[0038] The defoamer is polydimethylsiloxane.

[0039] The curing agent is ethylenediamine.

[0040] A preparation method of a flexible low-temperature spraying material for mines adapted to complex geological conditions, comprising the following steps:

[0041] Step 1: Add the vacuum-dehydrated polytetrahydrofuran into a flask, heat it up to 45 - 60 °C, add 4,4-diphenylmethane diisocyanate and nano-silica, mix them evenly, and stir and react at 60 °C for 2 h to obtain a polyurethane prepolymer;

[0042] Step 2: Weigh the alkylsiloxane and tetrahydroxymethylphosphonium sulfate, add them into an autoclave, heat up to 130 °C under stirring conditions, and stir for reaction; after the autoclave stirs and reacts for 3 hours, stop heating, continue to stir until the temperature drops to room temperature; open the autoclave, filter and separate the obtained solid and liquid, wash the filter cake with petroleum ether until clean, dry and crush it to obtain a reaction auxiliary agent;

[0043] Step 3: Add the organosilicon-modified acrylate emulsion into a reaction kettle, start stirring, and the stirring speed is 350 r / min;

[0044] Step 4: Slowly add the polyurethane prepolymer from Step 1 into the reaction kettle in Step 3, continue stirring for 45 minutes to make it evenly dispersed in the emulsion, then add epoxy resin and stir evenly.

[0045] Step 5: Sequentially add propylene glycol, plasticizer, reaction assistant, dispersant and defoamer, and stir for 20 - 40 min to make them fully mixed.

[0046] Step 6: Add filler and stir for 20 min to obtain a uniform mixed material.

[0047] Step 7: Before use, add curing agent into the mixed material and stir evenly, then spraying construction can be carried out.

[0048] Example 2

[0049] The flexible low-temperature spraying material for mines adapting to complex geological conditions comprises raw materials with the following weight parts: 6 parts of nano-silica, 15 parts of 4,4-diphenylmethane diisocyanate, 6 parts of polytetrahydrofuran, 3 parts of propylene glycol, 30 parts of epoxy resin, 20 parts of organosilicon-modified acrylate emulsion, 1 part of alkylsiloxane, 1 part of tetrahydroxymethyl phosphonium sulfate, 2 parts of plasticizer, 1 part of dispersant, 20 parts of filler, 2 parts of defoamer, and 5 parts of curing agent.

[0050] The alkylsiloxane is methyltriethoxysilane.

[0051] The filler includes quartz sand, talcum powder and mica powder. The particle size of the quartz sand is 1 mm, the particle size of the talcum powder is 0.2 mm, and the particle size of the mica powder is 0.01 mm. The volume ratio of quartz sand: talcum powder: mica powder is 3:4.5:2.5.

[0052] The dispersant is polyacrylate and sodium hexametaphosphate.

[0053] The particle size of the nano-silica is 5 μm.

[0054] The plasticizer is dioctyl adipate.

[0055] The defoamer is polyoxyethylene polyoxypropylene ether.

[0056] The curing agent is phthalic anhydride.

[0057] The preparation method of the flexible low-temperature spraying material for mines adapting to complex geological conditions comprises the following steps:

[0058] Step 1: Add the vacuum-dehydrated polytetrahydrofuran into a flask, heat up to 55 °C, add 4,4-diphenylmethane diisocyanate and nano-silica, mix evenly, and stir and react at 70 °C for 2 h to obtain a polyurethane prepolymer.

[0059] Step 2: Weigh alkyl siloxane and tetrahydroxymethyl phosphonium sulfate, add them into an autoclave, heat up to 140°C under stirring conditions, and carry out the reaction with stirring. After the autoclave stirs and reacts for 4 hours, stop heating, continue stirring until the temperature drops to room temperature. Open the autoclave, filter and separate the obtained solid and liquid, wash the filter cake with petroleum ether until clean, dry and crush it to obtain a reaction aid.

[0060] Step 3: Add the organosilicon-modified acrylate emulsion into a reaction kettle, start stirring, and the stirring speed is 400 r / min.

[0061] Step 4: Slowly add the polyurethane prepolymer from Step 1 into the reaction kettle in Step 3, continue stirring for 60 minutes to make it evenly dispersed in the emulsion, and then add epoxy resin and stir evenly.

[0062] Step 5: Add propylene glycol, plasticizer, reaction aid, dispersant and defoamer in sequence, stir for 25 min to make them fully mixed.

[0063] Step 6: Add filler and stir for 20 min to obtain a uniform mixed material.

[0064] Step 7: Before use, add the curing agent into the mixed material and stir evenly, then spraying construction can be carried out.

[0065] Example 3

[0066] A flexible low-temperature spraying material for mining adapted to complex geological conditions, comprising raw materials composed of the following parts by weight: 3 parts of nano-silica, 14 parts of 4,4-diphenylmethane diisocyanate, 7 parts of polytetrahydrofuran, 3 parts of propylene glycol, 28 parts of epoxy resin, 25 parts of organosilicon-modified acrylate emulsion, 2 parts of alkyl siloxane, 2 parts of tetrahydroxymethyl phosphonium sulfate, 3 parts of plasticizer, 2 parts of dispersant, 18 parts of filler, 2 parts of defoamer, and 2 parts of curing agent.

[0067] The alkyl siloxane is methyltrimethoxysilane.

[0068] The filler includes quartz sand, talcum powder and mica powder. The particle size of the quartz sand is 1.3 mm, the particle size of the talcum powder is 0.2 mm, and the particle size of the mica powder is 0.08 mm. The volume ratio of quartz sand: talcum powder: mica powder is 3:4.5:2.5.

[0069] The dispersant is sodium hexametaphosphate.

[0070] The particle size of the nano-silica is 5 μm.

[0071] The plasticizer is dibutyl phthalate and dioctyl adipate.

[0072] The defoamer is polydimethylsiloxane and polyoxyethylene polyoxypropylene ether.

[0073] The curing agent is ethylenediamine and phthalic anhydride.

[0074] A preparation method of a flexible low-temperature spraying material for mines adapted to complex geological conditions includes the following steps:

[0075] Step 1: Add vacuum-dehydrated polytetrahydrofuran into a flask, heat it up to 45°C, add 4,4-diphenylmethane diisocyanate and nano-silica, mix them evenly, and stir and react at 55°C for 2 hours to obtain a polyurethane prepolymer;

[0076] Step 2: Weigh alkylsiloxane and tetrahydroxymethyl phosphonium sulfate, add them into an autoclave, heat it up to 120°C under stirring conditions, and stir for reaction; after the autoclave stirs and reacts for 4 hours, stop heating, continue to stir until the temperature drops to room temperature; open the autoclave, filter and separate the obtained solid and liquid, wash the filter cake with petroleum ether until clean, dry and crush it to obtain a reaction aid;

[0077] Step 3: Add the organosilicon-modified acrylate emulsion into a reaction kettle, start stirring, and the stirring speed is 500 r / min;

[0078] Step 4: Slowly add the polyurethane prepolymer from Step 1 into the reaction kettle in Step 3, continue to stir for 30 minutes to make it evenly dispersed in the emulsion, and then add epoxy resin and stir evenly;

[0079] Step 5: Add propylene glycol, plasticizer, reaction aid, dispersant and defoamer in sequence, stir for 20 min to make them fully mixed;

[0080] Step 6: Add filler and stir for 15 min to obtain a uniform mixed material;

[0081] Step 7: Before use, add the curing agent into the mixed material, stir evenly, and then spraying construction can be carried out.

[0082] Example 4

[0083] A flexible low-temperature spraying material for mines adapted to complex geological conditions includes raw materials composed of the following parts by weight: 3 parts of nano-silica, 8 parts of 4,4-diphenylmethane diisocyanate, 8 parts of polytetrahydrofuran, 3 parts of propylene glycol, 30 parts of epoxy resin, 15 parts of organosilicon-modified acrylate emulsion, 2 parts of alkylsiloxane, 2 parts of tetrahydroxymethyl phosphonium sulfate, 6 parts of plasticizer, 3 parts of dispersant, 25 parts of filler, 4 parts of defoamer, and 6 parts of curing agent.

[0084] The alkylsiloxane is methyltrimethoxysilane.

[0085] The filler includes quartz sand, talcum powder, and mica powder. The particle size of the quartz sand is 1.5 mm, the particle size of the talcum powder is 0.5 mm, and the particle size of the mica powder is 0.1 mm. The volume ratio of quartz sand: talcum powder: mica powder is 3:4.5:2.5.

[0086] The dispersant is polyacrylate and sodium hexametaphosphate.

[0087] The particle size of the nano-silica is 10 μm.

[0088] The plasticizer is dioctyl adipate and epoxy fatty acid ester.

[0089] The defoamer is polydimethylsiloxane and polyoxyethylene polyoxypropylene ether.

[0090] The curing agent is ethylenediamine and resorcinol.

[0091] A preparation method of a flexible low-temperature spraying material for mines adapted to complex geological conditions includes the following steps:

[0092] Step 1: Add the vacuum-dehydrated polytetrahydrofuran into a flask, heat it up to 50 °C, add 4,4-diphenylmethane diisocyanate and nano-silica, and mix them evenly. Stir and react at 60 °C for 2 h to obtain a polyurethane prepolymer.

[0093] Step 2: Weigh alkyl siloxane and tetrahydroxymethyl phosphonium sulfate, add them into an autoclave, heat up to 110 °C under stirring conditions, and stir for reaction; after the autoclave has stirred and reacted for 2 hours, stop heating, continue to stir until the temperature drops to room temperature; open the autoclave, filter and separate the obtained solid and liquid, wash the filter cake with petroleum ether until clean, dry and crush it to obtain a reaction auxiliary agent.

[0094] Step 3: Add the organosilicon-modified acrylate emulsion into a reaction kettle, start stirring, and the stirring speed is 300 r / min.

[0095] Step 4: Slowly add the polyurethane prepolymer from Step 1 into the reaction kettle in Step 3, continue to stir for 50 minutes to make it evenly dispersed in the emulsion, and then add epoxy resin and stir evenly.

[0096] Step 5: Add propylene glycol, plasticizer, reaction auxiliary agent, dispersant and defoamer in sequence, stir for 40 min to make them fully mixed.

[0097] Step 6: Add the filler and stir for 20 min to obtain a uniform mixed material.

[0098] Step 7: Before use, add the curing agent into the mixed material, stir evenly, and then spraying construction can be carried out.

[0099] Comparative Example 1

[0100] Compared with Example 1, the spraying material does not include nano-silica and fillers, and the rest is the same as in Example 1.

[0101] A preparation method of a flexible mining spraying material, comprising the following steps:

[0102] Step 1: Add vacuum-dehydrated polytetrahydrofuran into a flask, heat up to 45 - 60 °C, add 4,4-diphenylmethane diisocyanate and mix, and stir and react at 60 °C for 2 h to obtain a polyurethane prepolymer;

[0103] Step 2: Weigh alkyl siloxane and tetrakis(hydroxymethyl) phosphonium sulfate, add them into an autoclave, heat up to 130 °C under stirring conditions and stir for reaction; after the autoclave stirs and reacts for 3 hours, stop heating, continue to stir until the temperature drops to room temperature; open the autoclave, filter and separate the obtained solid and liquid, wash the filter cake with petroleum ether until clean, dry and crush it to obtain a reaction aid;

[0104] Step 3: Add the organosilicon-modified acrylate emulsion into a reaction kettle, start stirring, and the stirring speed is 350 r / min;

[0105] Step 4: Slowly add the polyurethane prepolymer from Step 1 into the reaction kettle in Step 3, continue to stir for 45 minutes to make it evenly dispersed in the emulsion, and then add epoxy resin and stir evenly;

[0106] Step 5: Add propylene glycol, plasticizer, reaction aid, dispersant and defoamer in sequence, stir for 20 - 40 min to make them fully mixed;

[0107] Step 6: Before use, add a curing agent into the mixed material, stir evenly, and then spraying construction can be carried out.

[0108] Comparative Example 2

[0109] Compared with Example 1, the spraying material does not include epoxy resin and organosilicon-modified acrylate emulsion, and the rest is the same as in Example 1.

[0110] A preparation method of a flexible mining spraying material, comprising the following steps:

[0111] Step 1: Add vacuum-dehydrated polytetrahydrofuran into a flask, heat up to 45 - 60 °C, add 4,4-diphenylmethane diisocyanate and add nano-silica and mix evenly, and stir and react at 60 °C for 2 h to obtain a polyurethane prepolymer;

[0112] Step 2: Weigh alkyl siloxane and tetramethylol phosphonium sulfate, add them to an autoclave, heat up to 130 °C under stirring conditions, and carry out the reaction with stirring. After the autoclave has been stirred and reacted for 3 hours, stop heating and continue stirring until the temperature drops to room temperature. Open the autoclave, filter and separate the obtained solid and liquid, wash the filter cake clean with petroleum ether, dry and crush it to obtain a reaction aid.

[0113] Step 3: Add the organosilicon-modified acrylate emulsion to a reaction kettle, start stirring, and the stirring speed is 350 r / min.

[0114] Step 4: Slowly add the polyurethane prepolymer from Step 1 to the reaction kettle, continue stirring for 45 minutes, and stir evenly.

[0115] Step 5: Add propylene glycol, plasticizer, reaction aid, dispersant, and defoamer in sequence, stir for 20 - 40 min to make them fully mixed.

[0116] Step 6: Add filler and stir for 20 min to obtain a uniform mixed material.

[0117] Step 7: Before use, add the curing agent to the mixed material, stir evenly, and then spraying construction can be carried out.

[0118] The flexible spraying materials prepared in the above Examples 1 - 4 and Comparative Examples 1 - 2 were respectively subjected to performance tests, and the results are shown in Table 1.

[0119] Table 1 Performance test results

[0120]

[0121] Combined with the data in Table 1, it can be seen that the prepared flexible spraying sealing material has certain expansibility, adhesiveness, tensile resistance, air permeability, oxygen index, and flame retardancy when spraying and sealing in a mine environment. Thus, it can be shown that the flexible spraying sealing material is a plastic sealing material with high bond strength and air leakage blocking function, which is suitable for surface spraying of permanent roadways, driving roadways, and coal pillars underground to prevent leakage of harmful gases and weathering corrosion of support wire meshes; spraying and sealing of local gas leakage underground to prevent gas from entering the working face and causing harm. The organosilicon-modified acrylate emulsion endows the material with excellent flexibility, enabling it to adapt to the deformation of rocks and being not easy to crack or fall off; by adding nano-silica and propylene glycol, the performance stability of the material in a low-temperature environment is effectively improved, and good flexibility and adhesiveness can still be maintained in a low-temperature environment of -20 °C. Propylene glycol lowers the freezing point and improves low-temperature fluidity and stability; the synergistic effect between the curing agent and each component makes it have a strong adhesive force to the surface of mine roadways and can firmly adhere; the addition of alkyl siloxane and tetramethylol phosphonium sulfate makes the spraying material have good flame retardant performance and can effectively prevent the occurrence of fire accidents.

[0122] Therefore, the present invention adopts the above-mentioned flexible low-temperature spraying material for mines adapted to complex geological conditions and its preparation method. This material has good flexibility, adhesiveness and low-temperature resistance, can effectively protect facilities such as mine roadways under complex geological conditions and low-temperature environments, and the preparation method is simple and has low cost.

[0123] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that they can still modify or equivalently replace the technical solutions of the present invention, and these modifications or equivalent replacements cannot make the modified technical solutions deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. Flexible low-temperature spraying material for mining that adapts to complex geological conditions, characterized by: The invention comprises the following raw materials in parts by weight: 3-6 parts of nano silicon dioxide, 8-15 parts of 4,4-diphenylmethane diisocyanate, 4-8 parts of polytetrahydrofuran, 1-3 parts of propylene glycol, 20-30 parts of epoxy resin, 15-30 parts of organosilicon-modified acrylic emulsion, 1-2 parts of alkyl siloxane, 1-2 parts of tetrahydroxymethylphosphonium sulfate, 2-6 parts of plasticizer, 1-3 parts of dispersant, 12-25 parts of filler, 2-4 parts of defoamer and 2-6 parts of curing agent.

2. The flexible low-temperature spraying material for mining that is adapted to complex geological conditions according to claim 1 is characterized in that: The alkyl siloxane is one of methyltrimethoxysilane and methyltriethoxysiloxane.

3. The flexible low-temperature spraying material for mining that is adapted to complex geological conditions according to claim 1 is characterized in that: The filler comprises quartz sand, talcum powder and mica powder. The particle size of the quartz sand is 0.5-1.5 mm, the particle size of the talcum powder is 0.1-0.5 mm, and the particle size of the mica powder is 0.01-0.1 mm. The volume ratio of quartz sand: talcum powder: mica powder is 3:4.5:2.

5.

4. The flexible low-temperature spraying material for mining that is adapted to complex geological conditions according to claim 1 is characterized in that: The dispersant is at least one of polyacrylate and sodium hexametaphosphate.

5. The flexible low-temperature spraying material for mining that is adapted to complex geological conditions according to claim 1 is characterized in that: The particle size of the nano silicon dioxide is 5-10 μm.

6. The flexible low-temperature spraying material for mining that is adapted to complex geological conditions according to claim 1 is characterized in that: The plasticizer is one or more of dibutyl phthalate, dioctyl adipate, and epoxy fatty acid ester.

7. The flexible low-temperature spraying material for mining that is adapted to complex geological conditions according to claim 1 is characterized in that: The defoaming agent is at least one of polydimethylsiloxane and polyoxyethylene polyoxypropylene ether.

8. The flexible low-temperature spraying material for mining that is adapted to complex geological conditions according to claim 1 is characterized in that: The curing agent is at least one of ethylenediamine, phthalic anhydride and resorcinol.

9. The method for preparing a flexible low-temperature spraying material for mining that is adaptable to complex geological conditions according to any one of claims 1 to 8, characterized in that: The steps include: Step 1: Add the vacuum-dehydrated polytetrahydrofuran into a flask, heat it to 45-60° C., add 4,4-diphenylmethane diisocyanate and nano-silicon dioxide, mix them evenly, and stir and react at 55-70° C. for 2 hours to obtain a polyurethane prepolymer; Step 2: Weigh alkyl siloxane and tetrakis hydroxymethyl phosphonium sulfate, add them into an autoclave, raise the temperature to 110-150° C. under stirring conditions, and stir to react; after stirring the autoclave for 2-4 hours, stop heating, and continue stirring until the temperature drops to room temperature; The autoclave was opened, the solid and liquid obtained were separated by filtration, the filter cake was cleaned with petroleum ether, dried and crushed to obtain a reaction aid; Step 3: Add the organosilicon-modified acrylate emulsion into the reaction kettle and start stirring at a speed of 300-500 r / min; Step 4: slowly add the polyurethane prepolymer of step 1 into the reaction kettle of step 3, continue stirring for 30-60 minutes to make it evenly dispersed in the emulsion, then add epoxy resin and stir evenly; Step 5: Add propylene glycol, plasticizer, reaction aid, dispersant and defoamer in sequence, and stir for 20-40 minutes to fully mix; Step 6: Add filler and stir for 15-30 minutes to obtain a uniform mixture; Step 7. Before use, add the curing agent to the mixed material, stir evenly, and then start spraying.

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