A hydrogel fire extinguishing material for mining and its preparation method

Abstract

This invention discloses a hydrogel fire extinguishing material for mines and its preparation method, specifically relating to the field of fire extinguishing materials technology. The material comprises solid water glass, sodium bicarbonate, polyvinyl alcohol, silicon carbide, and water. The fire extinguishing gel material of this invention possesses the characteristics of simple preparation process, low raw material requirements, low cost, controllable gelation time, good water retention, environmental friendliness, excellent high-temperature stability, and excellent thermal conductivity. Even after complete water loss, it can still form a crack-free solid film on the coal surface to isolate the coal-oxygen reaction, effectively solving the problems of traditional inorganic fire extinguishing gels being prone to water loss and cracking, and releasing toxic gases during use. By changing the material ratio, gelation can be controlled over a wide time range, meeting different needs for on-site filling, long-distance transportation, and storage in coal mines.

Description

Technical Field

[0001] This invention relates to the field of fire prevention and extinguishing materials technology, specifically to a hydrogel fire prevention and extinguishing material for mining and its preparation method. Background Technology

[0002] China boasts vast coal reserves, diverse types, and a wide distribution, making it the world's largest coal producer and consumer. While my country's energy consumption structure is adjusting, with rapid increases in renewable, nuclear, and natural gas production capacity, the large base of coal demand and its coal-dominated resource endowment ensure that China will remain the world's most important coal market for a long time. Coal's dominant position in my country's energy supply will remain unchanged for the next decade or so. Coalfield fires are major disasters, not only wasting coal resources but also causing surface fissures, subsidence, air pollution, and even seriously threatening the lives of coal miners. To avoid property damage and casualties, safe and efficient mining is essential. Mine fires are one of the major natural disasters in coal mines, and spontaneous combustion of coal is a primary form of mine fire. Using fire-resistant materials is one of the effective measures to prevent spontaneous combustion of coal. Among these, colloidal materials, due to their excellent fire-resistant properties, have gradually become a research hotspot in mine fire-resistant materials. However, current mine fire-resistant colloids still suffer from poor water retention, high cost, and environmental hazards. Therefore, researching a new type of mine-use gel fire-resistant material is of great significance.

[0003] Patent CN202010424227.4 discloses a composite colloidal fire extinguishing material made from activated fly ash for mining and its preparation method, but it mainly consists of Al precipitated from fly ash through stepwise activation. 3+ Fe 3+ Ti 4+ High-valence metal ions can fully crosslink with polymers, and the activated fly ash solid phase can fill the network framework structure to form a solid-liquid two-phase composite colloidal material. This effectively increases the toughness, strength, and thermal stability of the colloid, and compared with traditional fly ash slurry, it has stronger water retention, encapsulation, and fire-extinguishing properties. However, its preparation method is complex, requires a large number of raw materials, and is therefore costly.

[0004] Patent CN202110265185.9 discloses a fire prevention and extinguishing material for underground coal mines and its preparation process. This patent specifies the metal crosslinking agent used, employing a crosslinking agent composite material. Because different metal crosslinking agents have different hydrolysis and polymerization rates, their gelation times also differ. Furthermore, since fire prevention and extinguishing materials for mines require pipeline transportation, the gelation time must be controlled within a reasonable range. Moreover, the patent uses a wider variety of raw materials, making the preparation method more complex and costly.

[0005] Patent CN202110531504.6 discloses a composite colloidal fire extinguishing material for coal mines and its preparation method, which generates a large amount of gas and forms a foam slurry, which is not environmentally friendly. Summary of the Invention

[0006] Therefore, this invention provides a mine hydrogel fire extinguishing material and its preparation method to solve the problems of poor water retention, high cost, and environmental harm of existing fire extinguishing materials.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] According to a first aspect of the present invention, a mine hydrogel fire extinguishing material is provided, the material comprising solid water glass, sodium bicarbonate, polyvinyl alcohol, silicon carbide and water.

[0009] Furthermore, the material comprises the following percentages of raw materials: 1-10% solid water glass, 2-3% sodium bicarbonate, 1-2% polyvinyl alcohol, 10-40% silicon carbide, and the balance being water.

[0010] Furthermore, the modulus of solid water glass is 3.2.

[0011] A method for preparing a mine hydrogel fire extinguishing material according to a second aspect of the present invention includes:

[0012] Step 1: Mix solid water glass, sodium bicarbonate, polyvinyl alcohol and silicon carbide until homogeneous to obtain a solid mixture;

[0013] Step 2: Add water to the solid mixture and stir until homogeneous to obtain the hydrogel fire extinguishing material.

[0014] Furthermore, all stirring was carried out at room temperature and pressure.

[0015] All the above steps were carried out at room temperature and pressure. As an improvement, the introduction of silicon carbide gave the gel fire extinguishing material excellent thermal conductivity.

[0016] Furthermore, in step two, the stirring conditions are 3-5 minutes and the stirring speed is 150-180 / min.

[0017] Furthermore, the method also includes step three, ultrasonic treatment, with an ultrasonic dispersion time of 30 minutes.

[0018] According to a third aspect of the present invention, a method for using a hydrogel fire extinguishing material for mining is provided, wherein the method is used for fire extinguishing in underground coal mines by high-pressure injection.

[0019] Water glass is a commonly used inorganic gel preparation material due to its low cost and environmental friendliness. When solid water glass is mixed with sodium bicarbonate and then water is added and stirred thoroughly, a gel is formed in a short time, making it a commonly used fire-fighting material in mines.

[0020] Sodium bicarbonate not only improves upon the shortcomings of traditional hydrogels that release toxic gases during use, posing a safety hazard, but its own dissolution process is also endothermic. As a coagulant accelerator, sodium bicarbonate can better exert the colloid's heat absorption and cooling effect after mixing.

[0021] Polyvinyl alcohol is a high molecular polymer with excellent structure. Water glass gels tend to be curdled and easily crack and break after gelation. However, after adding high molecular weight polyvinyl alcohol for modification, the polyvinyl alcohol molecular chains interweave between sodium silicate molecules, strengthening the intermolecular forces of sodium silicate, making the gel structure more compact, less prone to breakage, and with stronger integrity.

[0022] Silicon carbide, also known as carborundum, is a typical covalent compound produced by high-temperature smelting of raw materials such as quartz sand, sawdust, and petroleum coke. The four unpaired electrons of the C atom in its outermost shell form covalent bonds with one unpaired electron from each of the four surrounding Si atoms, creating a Si / C tetrahedron. The average bond energy between Si and C atoms is 3000 kJ / mol. Due to its strong covalent bond structure, silicon carbide possesses many excellent properties, such as high temperature resistance, high hardness, high strength, low coefficient of thermal expansion, excellent thermal shock resistance, high thermal conductivity, creep resistance, and chemical stability.

[0023] The present invention has the following advantages:

[0024] This gel uses a mixture of solid water glass and sodium bicarbonate as its base material, and incorporates polyvinyl alcohol, a high-molecular polymer that enhances intermolecular cross-linking, and silicon carbide, which possesses advantages such as good high-temperature stability, excellent thermal conductivity, and high hardness. Water is added to the solid mixture to obtain the desired gel. This gel overcomes the shortcomings of traditional water glass gels, such as excessive brittleness and environmental pollution. The gel is easy to prepare, with controllable gelation time, and can be formulated to meet the requirements of on-site filling and long-distance transportation and storage. This fire-extinguishing gel has high water retention, effectively locking in water injected into the coal body and preventing cracking. Its excellent thermal conductivity increases the thermal conductivity and specific heat capacity, thereby reducing heat release and increasing heat dissipation. It fully fills the gaps between coal particles to reduce coal-oxygen recombination reactions, thus inhibiting coal combustion and reignition, providing a fundamental guarantee for subsequent heat recovery from coalfield fires.

[0025] The hydrogel fire extinguishing material of the present invention can effectively lock in the water injected into the coal body. Its excellent thermal conductivity increases the thermal conductivity and specific heat capacity, thereby reducing heat release and increasing heat dissipation. It fully fills the gaps between the coal bodies to reduce the coal-oxygen complex reaction, thereby inhibiting the combustion and reignition of coal.

[0026] The fire-retardant gel material of this invention possesses the characteristics of simple preparation process, low raw material requirements, low cost, controllable gelation time, good water retention, environmental friendliness, excellent high-temperature stability, and excellent thermal conductivity. Even after complete water loss, it can still form a crack-free solid film on the coal surface to isolate the coal-oxygen reaction, effectively solving the problems of traditional inorganic fire-retardant gels that are prone to water loss and cracking, and release toxic gases during use. By changing the material ratio, gelation can be controlled over a wide range of time, meeting the different needs of on-site filling in coal mines and long-distance transportation and storage. Attached Figure Description

[0027] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are merely exemplary, and those skilled in the art can derive other embodiments based on the provided drawings without creative effort.

[0028] The structures, proportions, sizes, etc. illustrated in this specification are only for the purpose of assisting those skilled in the art in understanding and reading the content disclosed herein, and are not intended to limit the conditions under which the present invention can be implemented. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportions, or adjustments to the size, without affecting the effects and objectives that the present invention can produce, should still fall within the scope of the technical content disclosed in the present invention.

[0029] Figure 1 This is a diagram of a fire-resistant and extinguishing gel provided in Embodiment 1 of the present invention;

[0030] Figure 2 The CO release curve under programmed heating is provided as an experimental example of this invention.

[0031] Figure 3 The relative pressure-adsorption / desorption curves of coal and coal injected into each test gel are provided for experimental examples of the present invention; wherein, (a) - pure coal sample, (b) - gel No. 5 + coal, (c) - gel No. 8 + coal, (d) - gel No. 13 + coal;

[0032] Figure 4 The gel weight loss rate provided in the experimental examples of this invention;

[0033] Figure 5 The TG-DTG curves of the hydrogels provided in the experimental examples of the present invention are shown below; where (a) is hydrogel No. 5; (b) is hydrogel No. 8; and (c) is hydrogel No. 13. Detailed Implementation

[0034] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0035] Example 1

[0036] This embodiment provides a method for preparing a hydrogel fire extinguishing material for mining:

[0037] Mix 1g of solid water glass, 2g of sodium bicarbonate, 1g of polyvinyl alcohol, and 10g of silicon carbide until homogeneous. Add 86g of water to the solid mixture and stir thoroughly to obtain a fire-retardant gel. The fire-retardant gel is as follows: Figure 1 As shown.

[0038] Example 2

[0039] This embodiment provides a method for preparing a hydrogel fire extinguishing material for mining:

[0040] Take 5g of solid water glass, 2.5g of sodium bicarbonate, 1.5g of polyvinyl alcohol, and 20g of silicon carbide and mix them evenly. Add 71g of water to the solid mixture and stir thoroughly to obtain a fire-retardant gel.

[0041] Example 3

[0042] This embodiment provides a method for preparing a hydrogel fire extinguishing material for mining:

[0043] Take 8g of solid water glass, 3g of sodium bicarbonate, 2g of polyvinyl alcohol, and 40g of silicon carbide and mix them evenly. Add 47g of water to the solid mixture and stir thoroughly to obtain a fire-retardant gel.

[0044] Comparative Example 1

[0045] This comparative example provides a method for preparing a hydrogel fire extinguishing material for mining:

[0046] Take 1g of solid water glass, 2g of sodium bicarbonate and 1g of polyvinyl alcohol and mix them evenly. Add 86g of water to the solid mixture and stir thoroughly to obtain fire extinguishing gel.

[0047] Comparative Example 2

[0048] Patent CN202110531504.6 describes a composite colloidal fire extinguishing material for coal mines, made from the following raw materials in parts by weight: 1 part sodium carboxymethyl cellulose, 2 parts agar, 12 parts fly ash, 0.1 parts polyacrylamide, 6 parts crosslinking agent, 1 part sodium bicarbonate, 3 parts flame retardant, 3 parts foaming agent, and 90 parts water.

[0049] The crosslinking agent is a montmorillonite-supported metal ion crosslinking agent.

[0050] The crosslinking agent is prepared by the following steps:

[0051] 1) Slowly add sodium hydroxide solution dropwise to aluminum chloride solution. After the addition is complete, rapidly heat the solution to boiling point. Cool the solution after 30 minutes to obtain aluminum hydroxide.

[0052] 2) Add montmorillonite to aluminum hydroxide, stir and mix at 70℃ for 60-70 min, filter under reduced pressure, and dry to obtain the product; the molar ratio of sodium hydroxide to aluminum chloride is 2:1, the concentration of sodium hydroxide and aluminum chloride solution is 0.2mol / L, and the weight ratio of montmorillonite to aluminum chloride is 0.1mol:15g.

[0053] The flame retardant is a mixture of ammonium polyphosphate, magnesium oxide fiber and polyurethane fiber in a weight ratio of 1:1:1, wherein the magnesium hydroxide fiber has a diameter of 2-6μm and a length of 800-1000μm, and the polyimide fiber has a length of 1-2mm.

[0054] The above flame retardant is a modified flame retardant. The specific modification method is as follows: the flame retardant is immersed in an ethanol aqueous solution with a mass fraction of 2% KH550, stirred at 50-60℃ for 1 hour, filtered and dried to obtain the product; the weight ratio of the flame retardant to KH550 is 1:20.

[0055] The foaming agent is a mixture of hydrogen peroxide, hollow glass microspheres, and dimethyl silicone oil in a weight ratio of 2:1:0.2.

[0056] A method for preparing a composite colloidal fire extinguishing material for coal mines includes the following steps:

[0057] (1) Mix sodium carboxymethyl cellulose, agar and one-third water until well combined;

[0058] (2) Mix fly ash, polyacrylamide, crosslinking agent, flame retardant and one-third water evenly;

[0059] (3) Mix the mixture from steps (1) and (2) with the remaining ingredients until homogeneous to obtain the product.

[0060] Experimental Example

[0061] Test experiment:

[0062] The colloidal properties and performance of the fire-extinguishing gel materials prepared in Examples 1-3 and Comparative Examples 1-2 of the present invention were tested using the following method: Example 1 is designated as No. 5, Example 2 as No. 8, Example 3 as No. 13, and Comparative Example 1 as No. 0.

[0063] (1) Scanning Electron Microscope (SEM) Analysis

[0064] The microstructure and morphology of the sample surface were studied using scanning electron microscopy. The experiment was conducted at room temperature with an accelerating voltage of 3.0 kV. The samples were pre-treated with gold (10 nm) before testing.

[0065] Results: After improvements in materials and cross-linking methods, the PVA / SiC / WG hydrogel exhibited a complete structural structure without breakage or scattering. The substances within the system were tightly bound, forming a three-dimensional network structure with uniform and smooth pores. This not only compensated for the shortcomings of traditional hydrogels in terms of strength but also explained the superior performance of PVA / SiC / WG hydrogels in terms of water content and water retention. Simultaneously, the PVA polymer dispersed in the solution bonded to the WG gel. The active groups in the polymer accelerated the formation of tighter bonds between the material molecules, resulting in stronger intermolecular forces and attraction, ultimately forming a robust and dense material.

[0066] (2) Analysis of temperature program test

[0067] The device mainly consists of a programmed temperature control box, a coal sample container, a flow sensor, a temperature controller, a sampler, and gas tubing. The coal sample mass is approximately 20g, the gas tubing orifice diameter is 8–10mm, the temperature range is 30–210℃, and the heating rate is 1℃ / min. The collected gas sample is connected to a gas chromatograph through an inlet pipe, allowing analysis of the composition and concentration of gases produced during coal oxidation pyrolysis at different temperatures.

[0068] The CO release curve under programmed heating is shown below. Figure 2 As shown.

[0069] Depend on Figure 2 It can be seen that during the coal heating and oxidation process, the CO release patterns of raw coal, No. 5, No. 8, and No. 13 coal samples are roughly the same. In the initial heating stage, with temperatures ranging from 30℃ to 110℃, the CO release is relatively small and shows no significant change. When the temperature rises to 110℃, the CO concentration changes significantly, with the CO concentration curve changing from nearly horizontal to a sharp increase, approaching an exponential upward trend. The peak area for CO release rate is between 110℃ and 150℃, during which nearly 40% of the total CO is released. When the temperature rises to 150℃, the CO concentration continues to increase, but the trend is somewhat lower than in the second stage.

[0070] Compared with untreated raw coal, coal samples treated with gels No. 5, No. 8, and No. 13 showed significantly reduced CO production, and the temperature range at which significant changes in CO concentration began to occur was delayed. This indicates that PVA / SiC / WG hydrogels have a significant inhibitory and delaying effect on CO production. Among them, the coal sample treated with gel No. 8 produced the least amount of CO, indicating that PVA / SiC / WG hydrogel No. 8 has the most significant inhibitory effect on CO, and its histochemical properties are the best. Gel No. 13 is the next best, while gel No. 5 has the weakest inhibitory ability on CO. In conclusion, PVA / SiC / WG hydrogels have a significant inhibitory effect on CO release from coal. Different gel composition ratios show certain differences in their CO inhibitory effects, with gel No. 8 being the most effective at inhibiting CO production and exhibiting the best histochemical properties for coal spontaneous combustion.

[0071] (3) Water retention rate determination

[0072] The initial mass of each sample is recorded as m2. The beakers are then placed in a constant temperature drying oven, and the oven temperature is set to 60℃ to begin drying. After drying for 12 hours, the samples are removed, weighed, and recorded as m1. The water retention rate is then calculated using the following formula.

[0073]

[0074] ω i denoted as , where is the water retention rate of the colloid in the i-th experimental group, m1 is the remaining mass of the colloid after drying for 12 hours, and m2 is the initial mass of the colloid.

[0075] The results are shown in Table 1.

[0076] Table 1. Water retention rate of hydrogel

[0077]

[0078] As shown in Table 1, the water retention rate of the traditional hydrogel (No. 0) is 41.08%. The water retention rates of the new hydrogel materials with different ratios are all improved, with hydrogels No. 5, No. 8, and No. 13 reaching 55.00%, 63.95%, and 64.63%, respectively. Among them, hydrogel material No. 13 has the highest water retention rate, which is nearly 24% higher than that of the traditional hydrogel. Coal oxidation and spontaneous combustion is a process in which coal reacts with oxygen to generate heat, which gradually increases in temperature and eventually leads to combustion. Therefore, it is very important to cool down and dissipate heat during the coal oxidation and spontaneous combustion process so that the heat accumulated by the coal itself cannot meet the combustion requirements. Water is the main substance in the fire extinguishing and cooling process, so the water retention characteristics of the gel material are very important, and this characteristic will directly affect the fire extinguishing characteristics of the gel material.

[0079] (4) Blocking test

[0080] After placing coal pieces of various sizes into a large beaker, different proportions of fire-extinguishing gel were poured in to observe whether bubbles, cracks, or other phenomena appeared, thus testing the sealing performance of the prepared gel.

[0081] The results are shown in Table 2.

[0082] Table 2 Filling rate of gel materials in each test

[0083]

[0084] As shown in Table 2, the filling rates, from lowest to highest, are for gels No. 5, No. 0, No. 8, and No. 13, with values ​​of 22.94%, 42.11%, 61.34%, and 88.75%, respectively. Gel No. 5, due to its short gelation time, remained in the upper part of the pulverized coal seam and failed to penetrate to the bottom, resulting in incomplete filling of the voids in the lower part of the coal seam. Gel No. 0's gelation time allowed it to flow to the bottom of the coal seam, but the penetration was not integrated, leaving visible gaps in the voids. Gel No. 8 ensured sufficient fluidity to fully fill the voids and encapsulate the coal, creating a thin film on the coal surface to block oxygen. Gel No. 13 achieved the best filling rate, completely filling the voids and remaining in the pores with excellent setting speed, thus integrating the pulverized coal, reducing the contact area between coal and oxygen, and minimizing the risk of spontaneous combustion and the possibility of reignition.

[0085] (5) Oxygen barrier performance test

[0086] Sample preparation: Crush the coal into particles with a diameter of 2mm to 3mm. Take 10g of coal sample and place it in a beaker. Add the fire extinguishing gel of this invention until it covers the top layer of coal particles. This is called sample 1. Take 10g of coal sample of the same size and place it in a beaker. This is called sample 2. Place sample 1 and sample 2 in a constant temperature drying oven and dry them at 130℃ for 7 hours to allow the gel to completely lose water.

[0087] Pretreatment: The two groups of samples were degassed by vacuuming at a temperature of 100℃ for 1 hour.

[0088] Physical adsorption test: The specific surface area of ​​the two groups of samples was measured using an ASAP 24603.01 physical adsorption instrument (McClone Systems, Inc., USA). The adsorbent was nitrogen gas, and the test method was the BET method.

[0089] The relative pressure-adsorption / desorption curves of coal and coal-injected gels are shown below. Figure 3 As shown.

[0090] Depend on Figure 3It can be seen that the adsorption and desorption curves of raw coal and coal samples treated with gels No. 5, No. 8, and No. 13 all showed an increasing trend with increasing relative pressure. However, the adsorption and desorption of untreated raw coal far exceeded those of the coal samples treated with PVA / SiC / WG hydrogels. This indicates that PVA / SiC / WG hydrogels have an inhibitory effect on the physical adsorption of coal, and the inhibitory ability of PVA / SiC / WG hydrogels with different component ratios on the physical adsorption of coal varies to a certain extent. Taking the adsorption and desorption of raw coal as the standard, the coal sample treated with PVA / SiC / WG hydrogel No. 8 achieved the lowest values ​​in both adsorption and desorption parameters among the four groups of test samples, followed by the coal sample treated with PVA / SiC / WG hydrogel No. 5, and finally the coal sample treated with PVA / SiC / WG hydrogel No. 13. This indicates that PVA / SiC / WG hydrogel No. 8 has the most significant inhibitory effect on the physical adsorption capacity of coal, followed by PVA / SiC / WG hydrogel No. 5, and then PVA / SiC / WG hydrogel No. 13. In summary, PVA / SiC / WG hydrogel No. 13 has the weakest inhibitory performance on the physical adsorption of coal, while PVA / SiC / WG hydrogel No. 8 has the strongest inhibitory performance, making it the most suitable hydrogel fire extinguishing material for inhibiting physical adsorption in the field of coal fire prevention.

[0091] (6) Resistance test

[0092] To test the fire-extinguishing performance of the fire-retardant gel of this invention, a programmed temperature rise test was conducted to analyze the volume fraction of the index gas (CO) produced by coal oxidation pyrolysis. The inhibition rate was used to measure the inhibitory effect of the composite gel on coal. The inhibition rate refers to the rate of reduction in the volume fraction of CO released by the oxidation pyrolysis of the coal sample after inhibition treatment with the fire-extinguishing material, relative to the original coal sample, under the same temperature conditions. Specifically, it is calculated as follows:

[0093]

[0094] In the formula: E is the inhibition rate, %; s1 is the volume fraction of CO released from the raw coal sample, ‰; s2 is the volume of CO released from the coal sample after inhibition treatment, ‰.

[0095] Result: As Figure 2 The CO release curve under programmed heating is shown.

[0096] (7) Thermal stability test

[0097] 100g of gel and an equal mass of water were placed separately in a constant temperature drying oven and heated at a uniform rate within the temperature range of 80–180℃. Their weight loss rates were then measured. Figure 4 As shown.

[0098] As shown in the figure, the weight loss rates of hydrogels No. 5, No. 8, and No. 13 were 22.93%, 16.83%, and 17.88%, respectively. The weight loss rate gradually increased with increasing temperature. The weight loss trends of the three gels were roughly the same. When the temperature reached a certain value, the weight loss rate showed a peak. With the appearance of the peak, the time required for the gel weight loss rate to increase by one percentage point decreased as the temperature increased, and the weight loss curve increased sharply. This phenomenon indicates that the three-dimensional network structure inside the gel plays a strong water-locking role and is one of the main factors affecting the thermal stability of the gel.

[0099] The TG-DTG curve of the hydrogel is as follows Figure 5 As shown in the figure, gel dehydration can be roughly divided into three stages: First, the gel stabilization period, during which the gel mass does not change significantly, mainly because the temperature is still low, the gel's water retention is good, and the three-dimensional network structure of the gel can effectively lock in water molecules, preventing water loss; Second, the sudden dehydration period, in which the gel mass decreases sharply with the increase in temperature, and the maximum weight loss rate appears. The effect of temperature on the loss of water molecules in the gel system is greatest in this stage; Third, the continuous shrinkage period, in which the gel mass continues to decrease, but the trend is gradual. When the minimum weight loss is reached, the gel mass no longer changes with temperature, indicating that the gel system is completely dehydrated, the remaining components have been completely solidified, and temperature has no effect on the decomposition of the remaining components. The weight loss rate of gel No. 5 was the highest among the three groups of PVA / SiC / WG test gels, while the weight loss rate of gel No. 8 was the lowest. This indicates that gel No. 5 had the weakest water-fixing effect, while gel No. 8 had the strongest effect. The weight loss rate of gel No. 13 was close to that of gel No. 8, indicating that gel No. 8 also had a relatively good water-fixing effect.

[0100] Although the present invention has been described in detail above with general descriptions and specific embodiments, modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, all such modifications or improvements made without departing from the spirit of the present invention fall within the scope of protection claimed by the present invention.

Claims

1. A hydrogel fire-fighting material for mining, characterized in that, The material comprises the following percentages of raw materials: 1-10% solid water glass, 2-3% sodium bicarbonate, 1-2% polyvinyl alcohol, 10-40% silicon carbide, and the balance being water; The preparation method of the mineral hydrogel fire extinguishing material includes: Step 1: Mix solid water glass, sodium bicarbonate, polyvinyl alcohol and silicon carbide until homogeneous to obtain a solid mixture; Step 2: Add water to the solid mixture and stir until homogeneous to obtain the hydrogel fire extinguishing material.

2. The hydrogel fire extinguishing material for mining as described in claim 1, characterized in that, The modulus of solid water glass is 3.

2.

3. The hydrogel fire extinguishing material for mining as described in claim 1, characterized in that, All stirring was carried out at room temperature and pressure.

4. The mine hydrogel fire extinguishing material according to claim 1, characterized in that, In step two, the stirring conditions are 3-5 minutes and the stirring speed is 150-180 / min.

5. The hydrogel fire extinguishing material for mining according to claim 1, characterized in that, The method also includes step three, ultrasonic treatment, with an ultrasonic dispersion time of 30 minutes.

6. A method of using a mine hydrogel fire extinguishing material as described in any one of claims 1-5, characterized in that, The method described is a high-pressure injection method used for fire prevention and extinguishing in coal mines.

Images