Mine thermal power disaster resistance material and preparation method thereof

Abstract

The application relates to the technical field of blocking materials, and discloses a mine thermal dynamic disaster blocking material and a preparation method thereof. The mine thermal dynamic disaster blocking material comprises the following components by weight: 12-14 parts of polyvinyl alcohol, 8-10 parts of hydroxypropyl methyl cellulose, 6-8 parts of fly ash, 2-4 parts of a crosslinking agent, 3-5 parts of a blocking auxiliary agent, 1-2 parts of a foaming agent, 0.5-1 part of a foam stabilizer and 160-170 parts of first water; the foam stabilizer comprises the following components by weight: 10-15 parts of modified fly ash floating beads, 2-4 parts of a fatty alcohol polyoxyethylene ether and 20-25 parts of second water; wherein the modified fly ash floating beads are obtained by modifying fly ash floating beads with 2-hydroxybenzhydrazone. The technical scheme can solve the problem of poor foam stability in the related art.

Description

Technical Field

[0001] This invention relates to the field of inhibitory materials technology, specifically to an inhibitory material for thermal and dynamic disasters in mines and its preparation method. Background Technology

[0002] Mine thermal dynamic disasters refer to the collective term for primary and secondary disasters in coal mines caused by changes in the thermodynamic properties of disaster-causing factors that exceed controllable limits. These include five categories of disasters related to coal, gas, and coal dust: spontaneous combustion of coal, gas combustion, gas explosion, coal dust combustion, and coal dust explosion. To prevent and control mine thermal dynamic disasters, inhibitory materials are widely used. Currently, common inhibitory materials include gel-based inhibitors, foam-based inhibitors, and gel-foam composite inhibitors. Among these, gel-foam composite inhibitors combine the advantages of both gel and foam inhibitors, demonstrating significant application potential in the prevention and control of mine thermal dynamic disasters.

[0003] However, in practical applications, gel-foam composite inhibitory materials still have significant shortcomings. The foam used in existing products has poor stability and often breaks down and defoams rapidly after being sprayed onto the surface of an object, within the critical window period before the gel has fully gelled. This makes it impossible to maintain coverage of the object and block air leakage channels for a long time, greatly reducing the initial effect of fire prevention and extinguishing, and making it difficult to meet the requirements of long-term inhibitory materials for the prevention and control of thermal and dynamic disasters in mines.

[0004] Therefore, developing a new type of mine thermal hazard inhibitor material with strong foam stability after spraying and continuous inhibitory effect before and after gelation is of great practical significance. Summary of the Invention

[0005] This invention proposes a mine thermal disaster inhibitory material and its preparation method, which solves the problem of poor foam stability in related technologies.

[0006] The technical solution of the present invention is as follows:

[0007] This invention proposes a mine thermal hazard inhibitor material, comprising the following raw materials in parts by weight: 12-14 parts polyvinyl alcohol, 8-10 parts hydroxypropyl methylcellulose, 6-8 parts fly ash, 2-4 parts crosslinking agent, 3-5 parts inhibitory agent, 1-2 parts foaming agent, 0.5-1 part foam stabilizer, and 160-170 parts first water;

[0008] The foam stabilizer comprises the following raw materials in parts by weight: 10-15 parts modified fly ash cenospheres, 2-4 parts fatty alcohol polyoxyethylene ether, and 20-25 parts secondary water; the modified fly ash cenospheres are obtained by modifying fly ash cenospheres with 2-hydroxyphenylhydrazone.

[0009] As a further technical solution, the mass of the 2-hydroxyphenylhydrazone is 3.5% to 4.2% of the mass of fly ash cenospheres, preferably 3.9%.

[0010] This invention discloses a mine thermal hazard inhibitory material. By limiting the mass of 2-hydroxyphenylhydrazone in the foam stabilizer to 3.5%~4.2% of the mass of fly ash cenospheres, the inhibition rate of the mine thermal hazard inhibitory material can be effectively improved. When the mass of 2-hydroxyphenylhydrazone is less than 3.5% of the mass of fly ash cenospheres, the 2-hydroxyphenylhydrazone cannot fully cover the surface of the fly ash cenospheres, and the fly ash cenospheres will still agglomerate, failing to play a role in stabilizing the foam. When the mass of 2-hydroxyphenylhydrazone is greater than 4.2% of the mass of fly ash cenospheres, the excess 2-hydroxyphenylhydrazone will accumulate on the surface of the cenospheres, forming a redundant layer, which not only increases the raw material cost but also affects the inhibition rate. However, limiting the mass of 2-hydroxyphenylhydrazone in the foam stabilizer to 3.5%~4.2% of the mass of fly ash cenospheres can effectively inhibit the agglomeration of fly ash cenospheres, improve their dispersibility in the foam system and their supporting stability on the foam film, thereby further improving the inhibition rate of the mine thermal hazard inhibitory material.

[0011] As a further technical solution, the preparation method of the modified fly ash cenospheres includes the following steps: dispersing 2-hydroxyphenylhydrazone in anhydrous ethanol, then adding fly ash cenospheres and mixing, drying, to obtain modified fly ash cenospheres.

[0012] As a further technical solution, the mixing temperature is 50~60℃ and the time is 2~4h.

[0013] As a further technical solution, the particle size of the fly ash cenospheres is 130~160μm.

[0014] As a further technical solution, the raw materials of the inhibition aid include 2,6-dihydroxynaphthalene, mica powder and 5-bromocresol in a mass ratio of 1~2:83:5.

[0015] As a further technical solution, the preparation method of the inhibition aid includes the following steps: dispersing 2,6-dihydroxynaphthalene in anhydrous ethanol, adding mica powder, stirring at 50~60℃ for 1~2h, then adding 5-bromocresol, stirring at 40~50℃ for 2~3h, and drying to obtain the inhibition aid.

[0016] This invention discloses a mine thermal hazard inhibitor material containing polyvinyl alcohol and a crosslinking agent. After spraying, it gradually forms a gel material covering the surface of the object. However, the gel material is prone to shrinkage due to water loss at high temperatures, leading to a decrease in its coverage area and ultimately a reduction in the inhibitory effect of the mine thermal hazard inhibitor material. Adding mica powder as a filler can reduce the shrinkage rate of the gel material; however, mica powder is prone to agglomeration, hindering its effectiveness. This invention treats the mica powder with 2,6-dihydroxynaphthalene, resulting in more uniform dispersion and better support for the gel material, thus reducing its shrinkage rate. Furthermore, this invention further treats it with 5-bromotryptol, which not only enhances the dispersibility of the mica powder and significantly improves its supporting effect as a filler, but also further reduces its shrinkage rate. Additionally, it provides a certain flame-retardant effect, further improving the overall flame-retardant performance of the mine thermal hazard inhibitor material.

[0017] As a further technical solution, the crosslinking agent is one or both of boric acid and aluminum citrate.

[0018] As a further technical solution, the foaming agent is composed of sodium secondary alkyl sulfonate and rosin acid polyoxyethylene ester in a mass ratio of 1:1.

[0019] As a further technical solution, the particle size of the fly ash is 70~80μm.

[0020] This invention also proposes a method for preparing a mine thermal hazard inhibitory material, comprising the following steps:

[0021] S1. Mix polyvinyl alcohol, hydroxypropyl methylcellulose, fly ash and half the mass of first water for 15-20 minutes to obtain mixture I;

[0022] S2. Mix the foaming agent, foam stabilizer and one-quarter of the mass of first water for 15-20 minutes to obtain mixture II;

[0023] S3. Add the crosslinking agent, the inhibitor, the remaining first water and the mixture II together to the mixture I, mix evenly, and obtain a mine thermal hazard inhibitor material.

[0024] The working principle and beneficial effects of this invention are as follows:

[0025] This invention significantly improves the stability of foam in inhibitory materials by introducing 2-hydroxyphenylhydrazone-modified fly ash cenospheres into foam stabilizers, thereby increasing the inhibition rate of mine thermal hazard inhibitory materials. In existing technologies, adding smoothly shaped aggregates such as fly ash cenospheres is commonly used to enhance foam stability; however, fly ash cenospheres have an inherent tendency to agglomerate, leading to uneven dispersion in the foam system and consequently a decrease in overall foam stability. This makes it difficult for the inhibitory material to continuously cover the surface of the object and effectively seal air leakage channels before gelation, ultimately reducing the inhibition rate of mine thermal hazard inhibitory materials.

[0026] The 2-hydroxyphenylhydrazone-modified fly ash cenospheres used in this invention can effectively inhibit the agglomeration tendency of fly ash cenospheres, enabling them to achieve uniform dispersion in the foam system. The uniformly distributed modified fly ash cenospheres provide stable support for the foam film, significantly improving the stability of the foam and thus further enhancing the inhibition rate of the mine thermal hazard inhibitor. Detailed Implementation

[0027] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0028] In the following examples and comparative examples, polyvinyl alcohol (PVA1788), hydroxypropyl methylcellulose (50,000 viscosity, 2%, 25°C), fly ash (average particle size 74 μm), fly ash cenospheres (average particle size 150 μm), fatty alcohol polyoxyethylene ether (AEO-9), sodium secondary alkyl sulfonate (SAS-60), and rosin acid polyoxyethylene ester (OEO-115) are used.

[0029] Example 1

[0030] A method for preparing a mine thermal hazard inhibitory material includes the following steps:

[0031] S1. Mix 12 parts polyvinyl alcohol, 8 parts hydroxypropyl methylcellulose, 6 parts fly ash and 80 parts water for 20 minutes to obtain mixture I.

[0032] S2. Stir 1 part foaming agent, 0.5 part foam stabilizer and 40 parts water for 15 minutes to obtain mixture II;

[0033] S3. Add 2 parts boric acid, 3 parts inhibitor, 40 parts water and mixture II to mixture I, mix evenly to obtain a mine thermal hazard inhibitor material;

[0034] Among them, the inhibitor is mica powder;

[0035] The foaming agent is composed of sodium secondary alkyl sulfonate and rosin acid polyoxyethylene ester in a mass ratio of 1:1;

[0036] The foam stabilizer comprises the following raw materials in parts by weight: 10 parts modified fly ash cenospheres, 2 parts fatty alcohol polyoxyethylene ether, and 20 parts water.

[0037] The preparation method of modified fly ash cenospheres includes the following steps: dispersing 2-hydroxyphenylhydrazone in anhydrous ethanol, then adding fly ash cenospheres, heating to 55℃ and mixing for 3 hours, and drying to obtain modified fly ash cenospheres; wherein, the mass of 2-hydroxyphenylhydrazone is 3.5% of the mass of fly ash cenospheres; and the mass-volume ratio of fly ash cenospheres to anhydrous ethanol is 1g:13mL.

[0038] Example 2

[0039] Compared with Example 1, the only difference in Example 2 is that the preparation method of a mine thermal hazard inhibitory material in this example includes the following steps:

[0040] S1. Mix 13 parts polyvinyl alcohol, 9 parts hydroxypropyl methylcellulose, 7 parts fly ash and 82 parts water for 20 minutes to obtain mixture I.

[0041] S2. Stir 1.5 parts of foaming agent, 0.8 parts of foam stabilizer and 41 parts of water for 15 minutes to obtain mixture II;

[0042] S3. Add 3 parts aluminum citrate, 4 parts inhibitor, 41 parts water and mixture II together to mixture I, mix evenly to obtain a mine thermal hazard inhibitor material;

[0043] The foam stabilizer comprises the following raw materials in parts by weight: 13 parts modified fly ash cenospheres, 3 parts fatty alcohol polyoxyethylene ether, and 22 parts water.

[0044] Example 3

[0045] Compared with Example 1, the only difference in Example 3 is that the preparation method of a mine thermal hazard inhibitory material in this example includes the following steps:

[0046] S1. Mix 14 parts polyvinyl alcohol, 10 parts hydroxypropyl methylcellulose, 8 parts fly ash and 85 parts water for 20 minutes to obtain mixture I.

[0047] S2. Stir 2 parts of foaming agent, 1 part of foam stabilizer and 42.5 parts of water for 15 minutes to obtain mixture II;

[0048] S3. Add 2 parts aluminum citrate, 2 parts boric acid, 5 parts inhibitor, 42.5 parts water and mixture II together to mixture I, mix evenly to obtain a mine thermal hazard inhibitor material;

[0049] The foam stabilizer comprises the following raw materials in parts by weight: 15 parts modified fly ash cenospheres, 4 parts fatty alcohol polyoxyethylene ether, and 25 parts water.

[0050] Example 4

[0051] Compared with Example 1, the only difference in Example 4 is that the mass of 2-hydroxyphenylhydrazone in the modified fly ash cenospheres in this example is 3.9% of the mass of fly ash cenospheres.

[0052] Example 5

[0053] Compared with Example 1, the only difference in Example 5 is that the mass of 2-hydroxyphenylhydrazone in the modified fly ash cenospheres in this example is 4.2% of the mass of fly ash cenospheres.

[0054] Example 6

[0055] Compared with Example 1, the only difference in Example 6 is that the inhibitors in this example include 2,6-dihydroxynaphthalene, mica powder and 5-bromocresol;

[0056] The method for preparing the inhibition aid includes the following steps: dispersing 2,6-dihydroxynaphthalene in anhydrous ethanol, adding mica powder, stirring at 55°C for 1.5 h, then adding 5-bromocresol, stirring at 45°C for 2.5 h, and drying to obtain the inhibition aid; wherein, the mass ratio of 2,6-dihydroxynaphthalene, mica powder and 5-bromocresol is 1:83:5; and the mass-volume ratio of mica powder and anhydrous ethanol is 1 g:10 mL.

[0057] Example 7

[0058] Compared with Example 6, the only difference in Example 7 is that, in this example, the mass ratio of 2,6-dihydroxynaphthalene, mica powder and 5-bromocresol is 1.5:83:5.

[0059] Example 8

[0060] Compared with Example 6, the only difference in Example 8 is that the mass ratio of 2,6-dihydroxynaphthalene, mica powder and 5-bromocresol is 2:83:5.

[0061] Example 9

[0062] Compared with Example 6, the only difference in Example 9 is that the inhibitor in this example includes 2,6-dihydroxynaphthalene and mica powder;

[0063] The method for preparing the inhibition aid includes the following steps: dispersing 2,6-dihydroxynaphthalene in anhydrous ethanol, adding mica powder, stirring at 55°C for 1.5 h, and obtaining the inhibition aid; wherein, the mass ratio of 2,6-dihydroxynaphthalene to mica powder is 1:83; and the mass-volume ratio of mica powder to anhydrous ethanol is 1 g:10 mL.

[0064] Comparative Example 1

[0065] Compared with Example 1, the only difference in Comparative Example 1 is that the modified fly ash cenospheres were replaced with an equal amount of fly ash cenospheres.

[0066] Comparative Example 2

[0067] Compared with Example 1, the only difference of Comparative Example 2 is that it does not contain an inhibitor.

[0068] The mine thermal hazard inhibitory materials prepared in Examples 1-9 and Comparative Examples 1-2 were tested according to the following methods:

[0069] 1. Inhibition performance: The inhibition rate at a coal temperature of 100℃ was tested according to the test methods specified in MT / T 700-2019 "General Technical Conditions for Fire Inhibitors for Coal Mines".

[0070] 2. Water loss rate: After spraying the mine thermal disaster inhibitory material, the sample was left at room temperature for 30 minutes to form a gel sample. 50g of gel sample and 50g of water were placed in a 200℃ constant temperature drying oven and left for 10 minutes. The water loss rate was then measured.

[0071] The test results are shown in Tables 1 and 2:

[0072] Table 1 Test results of the inhibition performance of materials for inhibiting thermal and dynamic disasters in mines

[0073]

[0074] As shown in Table 1, the comparison between Examples 1-5 and Comparative Example 1 indicates that the addition of 2-hydroxyphenylhydrazone-modified fly ash cenospheres can significantly improve the stability of foam, thereby increasing the inhibition rate of the mine thermal hazard inhibition material.

[0075] Table 2. Test results of water loss rate of mine thermal hazard inhibitory materials

[0076]

[0077] As shown in Table 2, the comparison between Examples 1, 6-9 and Comparative Example 2 indicates that the addition of the inhibitor in the mine thermal hazard inhibitor material of the present invention can significantly reduce the water loss rate of the mine thermal hazard inhibitor material.

[0078] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A mine thermal dynamic disaster resistance material, characterized in that, The raw material comprises the following components by weight: polyvinyl alcohol 12-14 parts, hydroxypropyl methylcellulose 8-10 parts, fly ash 6-8 parts, crosslinking agent 2-4 parts, resistance aid 3-5 parts, foaming agent 1-2 parts, foam stabilizer 0.5-1 part, and first water 160-170 parts; The foam stabilizer comprises the following components by weight: modified fly ash floating bead 10-15 parts, fatty alcohol polyoxyethylene ether 2-4 parts, and second water 20-25 parts; the modified flyash floating bead is obtained by modifying fly ash floating bead with 2-hydroxyphenylhydrazone; The mass of the 2-hydroxyphenylhydrazone is 3.5%-4.2% of the mass of the fly ash floating bead.

2. The mine thermal disaster prevention material according to claim 1, characterized in that, The preparation method of the modified fly ash floating bead comprises the following steps: dispersing 2-hydroxyphenylhydrazone in anhydrous ethanol, then adding fly ash floating bead and mixing, and drying to obtain the modified fly ash floating bead.

3. The mine thermal disaster prevention material according to claim 1, characterized in that, The particle size of the fly ash floating bead is 130-160 μm.

4. The mine thermal disaster prevention material according to claim 1, wherein The raw material of the resistance aid comprises 2,6-dihydroxynaphthalene, mica powder and 5-bromo chromanol in a mass ratio of 1-2:83:

5.

5. The mine thermal disaster arrestant material according to claim 4, characterized in that, The preparation method of the resistance aid comprises the following steps: dispersing 2,6-dihydroxynaphthalene in anhydrous ethanol, then adding mica powder, stirring at 50-60 ℃ for 1-2 h, then adding 5-bromo chromanol, stirring at 40-50 ℃ for 2-3 h, and drying to obtain the resistance aid.

6. The mine thermal disaster retardant material according to claim 1, wherein The crosslinking agent is one or both of boric acid and aluminum citrate.

7. The mine thermal disaster prevention material according to claim 1, wherein The foaming agent is composed of sodium secondary alkyl sulfonate and rosin acid polyoxyethylene ester in a mass ratio of 1:

1.

8. The mine thermal disaster prevention material according to claim 1, wherein The particle size of the fly ash is 70-80 μm.

9. A method for preparing a mine thermal dynamic disaster resistance material, for preparing the mine thermal dynamic disaster resistance material according to any one of claims 1-8, characterized in that, The method comprises the following steps: S1, mixing polyvinyl alcohol, hydroxypropyl methylcellulose, fly ash and half of the mass of the first water for 15-20 min to obtain mixture I; S2, mixing the foaming agent, the foam stabilizer and one quarter of the mass of the first water for 15-20 min to obtain mixture II; S3, adding the crosslinking agent, the resistance aid, the remaining first water and the mixture II into the mixture I, and mixing uniformly to obtain a mine thermal dynamic disaster resistance material.

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