Fire extinguishing agent special for forest grassland

Abstract

The invention discloses a fire extinguishing agent special for forests and grassland, and belongs to the technical field of fire extinguishing agents. The fire extinguishing agent special for the forest grassland comprises the following components in parts by weight: 2-6 parts of a surfactant, 10-35 parts of modified blast furnace slag, 10-15 parts of organic modified ettringite, 0.5-4 parts of a foaming agent, 0.5-2 parts of a foam stabilizer, 0-10 parts of polyethylene glycol, 0-10 parts of urea, 0.5-1.0 part of a corrosion inhibitor, 3-5 parts of a composite flame retardant and 50-80 parts of water. The modified blast furnace slag is obtained by modifying blast furnace slag subjected to acid and alkali treatment by adopting carboxymethyl cellulose; the organic modified ettringite is modified by adopting tannic acid. According to the fire extinguishing agent special for the forest grassland, the raw materials are environmentally friendly and degradable, the cost is low, fire extinguishing and degradation can be rapidly conducted, fire spreading is effectively restrained, smoldering fire reburning is prevented, residues obtained after fire extinguishing are beneficial to vegetation recovery and water and soil loss prevention, the water utilization rate is increased, and the fire extinguishing agent can be suitable for any fire fighting equipment.

Description

Technical Field

[0001] The present invention belongs to the technical field of fire extinguishing agents, and in particular relates to a special fire extinguishing agent for forests and grasslands and a preparation method thereof. Background Art

[0002] Forest and grassland fires are highly sudden, destructive, rapidly spreading, prone to reignition, and difficult to control natural disasters. They not only damage the ecological environment and biodiversity, but also cause significant losses to human life and property. As global temperatures continue to rise, forest and grassland fires are becoming more frequent and larger in scale, making them increasingly difficult to extinguish. Due to its widespread availability, low cost, and environmental friendliness, water is the primary fire extinguishing agent for forest and grassland fires in diverse terrain, structures, and climatic conditions. However, forest and grassland fires are characterized by their intense intensity, rapid spread, and difficulty in control. Furthermore, water's high mobility and short residence time on burning materials can lead to water shortages and low water utilization in practice. This makes it difficult to prevent the spread of fires and increases the risk of rekindling. It also wastes water resources. Excessive use of water can cause geological disasters such as soil erosion and landslides, hindering rapid ecological recovery.

[0003] At present, the fire extinguishing agents that are gradually replacing water in the fight against forest and grassland fires mainly include halogenated fire extinguishing agents, Class A foam fire extinguishing agents, dry powder fire extinguishing agents, and hydrogel fire extinguishing agents. Halon fire extinguishing agents mainly extinguish fires through chemical inhibition and cooling effects. They have low fire extinguishing concentrations and fast fire extinguishing rates. However, the bromine and chlorine produced by the combustion of halogenated fire extinguishing agents can damage the atmospheric ozone layer, and their use is now restricted both domestically and internationally. The environmentally friendly perfluorohexanone fire extinguishing agent has the phenomenon of promoting the development of fires at low concentrations, and the energy generated by thermal runaway is poorly transferred, making it easy to reignite, and the cost is relatively high. Class A foam fire extinguishing agents are composed of surfactants, foaming agents, stabilizers, etc., and have advantages such as strong permeability, water conservation, and prevention of reignition. However, they need to be sprayed repeatedly under high temperature conditions, which is relatively expensive. The combustion products may pollute the soil and water bodies and do not take advantage of the post-disaster ecological environment recovery. The foam is easily blown away by air waves or strong winds, affecting the coverage and fire extinguishing effect, further increasing the cost. Dry powder fire extinguishing agents are primarily composed of inorganic salt powders (such as ammonium phosphate and sodium bicarbonate). They require no water, extinguish fires quickly, and are easily portable. However, they are prone to dispersion, have poor coverage efficiency, and affect visibility, hindering rescue efforts. They only extinguish fires on the surface, making them prone to reignition. Post-extinguishing residues affect the recovery of forest and grassland vegetation, and dust pollutes the air, endangering the health of firefighters. Hydrogel fire extinguishing agents, primarily organic hydrogels and biomass hydrogels, offer advantages such as rapid cooling, low agent usage, water conservation, reduced rekindling rates, and environmental friendliness. However, they are relatively expensive, prone to clogging of ordinary water pumps, and have poor low-temperature resistance. The film left after extinguishing a fire affects ecological recovery, and their high viscosity makes them difficult to extinguish from a distance, limiting their application in forest and grassland fires.

[0004] Invention patent CN202010320696.1 discloses a forest fire extinguishing composition, which is a polymer gel material formed by first modifying polyacrylate with a surfactant, and then adding enhancers, coordinators, thickeners and other components and mixing them evenly. The polymer gel material is environmentally friendly, non-corrosive, naturally degradable and residue-free, can achieve rapid fire extinguishing and anti-reignition properties, and is beneficial to vegetation recovery and water and soil conservation; however, polyacrylate as the main component has a slow natural decomposition rate, which affects the air and water permeability of the soil, delays the vegetation recovery time, and has poor resistance to high and low temperatures, that is, the polymer chain is easy to break when the temperature exceeds 80°C, and phase separation occurs below 5°C, and the gel grid breaks, resulting in low fire extinguishing efficiency under high and low temperature conditions. Invention patent CN202410409761.6 discloses a forest fire extinguishing agent, which first uses a coupling agent to modify the surface of multiple flame retardants, and then coats the modified flame retardants with a hydrophobic polymer monomer. Under the action of the hydrophilic polymer, in situ polymerization is formed to form a coating with a core-shell structure, which can be quickly dispersed in water. After adding 10-20 times of water for dilution, the fire extinguishing effect can reach the "2A" high-efficiency standard. It has no corrosion to metal and no toxic substances are produced at high temperatures; however, the fire extinguishing agent is not effective in controlling the spread of fire, and the risk of re-ignition is high. It is generally not effective in extinguishing large-scale forest and grassland fires. Summary of the Invention

[0005] The main purpose of the present invention is to provide a special fire extinguishing agent for forests and grasslands. The raw materials are environmentally friendly and degradable, the cost is low, the fire can be quickly extinguished and degraded, the spread of fire can be effectively suppressed, and the re-ignition of the fire can be prevented. The residue after fire extinguishing is conducive to vegetation recovery and prevention of soil erosion, thereby improving water utilization rate and being applicable to any fire-fighting equipment.

[0006] To achieve the purpose of the present invention, the present invention provides a forest and grassland fire extinguishing agent, comprising the following components in parts by weight: 2-6 parts of a surfactant, 10-35 parts of modified blast furnace slag, 10-15 parts of organically modified ettringite, 0.5-4 parts of a foaming agent, 0.5-2 parts of a foam stabilizer, 0-10 parts of polyethylene glycol, 0-10 parts of urea, 0.5-1.0 parts of a corrosion inhibitor, 3-5 parts of a composite flame retardant, and 50-80 parts of water;

[0007] The modified blast furnace slag is prepared by modifying the acid- and alkali-treated blast furnace slag using carboxymethyl cellulose.

[0008] Furthermore, the preparation method of the modified blast furnace slag is:

[0009] P1. Place the blast furnace slag in a 0.01 mol / L hydrochloric acid solution, stir for 2-3 hours, filter, repeatedly wash with water, dry, grind, and sieve through 200 mesh to obtain acid-washed blast furnace slag;

[0010] P2. The pickled blast furnace slag was added to a sodium hydroxide solution, the pH value was adjusted to 10-12, the reaction was stirred for 1-2h, filtered, washed with water until neutral, and dried to obtain pretreated blast furnace slag;

[0011] P3. Add pretreated blast furnace slag and ammonium polyphosphate to an appropriate amount of water, ultrasonically treat for 20-30 minutes, then add carboxymethyl cellulose, ultrasonicate at 50-60℃ for 30 minutes, add sodium hydroxide solution to adjust the pH value to 8, stir and react at 70-80℃ for 2-4 hours, filter, wash the precipitate with water until it is neutral, dry, grind, and sieve through 400 mesh to obtain modified blast furnace slag.

[0012] Furthermore, the concentration of the sodium hydroxide solution is 0.1-1.0 mol / L;

[0013] The amount of ammonium polyphosphate added is 5-10% of the mass of the pretreated blast furnace slag;

[0014] The added amount of the carboxymethyl cellulose is 4-8% of the mass of the pretreated blast furnace slag.

[0015] Blast furnace slag is a byproduct of steel production, primarily derived from the blast furnace ironmaking process. If not properly handled, this slag not only occupies significant land resources but also causes serious environmental pollution. Currently, blast furnace slag is primarily used in China for construction materials, such as cement, concrete, and slag soil. However, the calcium and magnesium elements it provides can promote plant growth, improve soil structure, and enhance water retention and air permeability, but its use in these applications is rarely seen domestically or internationally.

[0016] The blast furnace slag of the present invention is first subjected to acid and alkali treatment in sequence, and then dispersed evenly with ammonium polyphosphate under ultrasonic conditions, and then modified by adding carboxymethyl cellulose under alkaline conditions. The modified blast furnace slag is added to the fire extinguishing agent, which not only improves the rapid fire extinguishing and anti-reignition effects of the present invention, but also ensures that the fire extinguishing agent of the present invention has good foam stability, and in a high temperature and windy environment, prevents the fire extinguishing agent from drifting, improves the coverage efficiency of the fire extinguishing agent, and plays the role of isolating oxygen and flame retardant. During the fire extinguishing process, the blast furnace slag covers the surface of the burning material, isolates oxygen, inhibits further combustion of the combustible material, and prevents its reignition; in addition, the inorganic components and porous structure in the blast furnace slag can absorb heat, capture free radicals, absorb toxic gases after combustion, adsorb volatiles, etc., which can delay combustion and play a flame retardant role; at the same time, the blast furnace slag remaining after the fire is extinguished can enhance the water retention and air permeability of the soil, provide medium elements such as calcium and magnesium, promote vegetation recovery, and effectively improve the rapid recovery of the ecological environment. The addition of ammonium polyphosphate ensures the foam stabilizer in the fire extinguishing agent of the present invention, further enhancing the flame retardancy and fire extinguishing efficiency of the present invention, effectively improving the coverage efficiency of blast furnace slag, and preventing re-ignition. The addition of carboxymethyl cellulose increases the hydrophilicity of blast furnace slag, ensuring that the addition of blast furnace slag does not reduce the foam stability of the fire extinguishing agent, and prolongs the foam stability, improving the permeability and coverage cooling effect of the fire extinguishing agent, isolating oxygen, and preventing re-ignition.

[0017] It is worth noting that if the amount of modified blast furnace slag used is too much, it will not only increase the burden of ecological restoration, but also affect the stability of the fire extinguishing agent foam, thereby reducing the fire extinguishing efficiency; if the amount of modified blast furnace slag used is too little, the fire extinguishing agent will easily spread, the cost will increase, the speed of controlling the spread of fire will decrease, and the risk of re-ignition will increase.

[0018] Furthermore, the surfactant is any one or more of lignin sulfonate, succinate sulfonate, alkyl glyceryl ether sulfonate, sodium lauroyl isethionate, α-sulfo fatty acid methyl ester, and sodium linear alkylbenzene sulfonate. Preferred surfactants of the present invention are all biodegradable anionic surfactants with excellent wetting and permeability, promoting the formation of extinguishing agent bubbles and ensuring that moisture more easily penetrates deep into the burning vegetation, blocking combustion and preventing re-ignition.

[0019] Furthermore, the preparation method of the organically modified ettringite is as follows: adding acetic acid solution to a 3-6wt% tannic acid solution to adjust the pH value to 4-5, then adding dried ettringite, stirring and reacting at room temperature for 3-5 hours, filtering, washing with deionized water, and vacuum drying to obtain the organically modified ettringite.

[0020] The present invention uses tannic acid to modify ettringite, which improves the compatibility between ettringite and components such as surfactants and modified blast furnace slag. It also has excellent hydrophilicity and adsorption properties, allowing it to be evenly dispersed in a fire extinguishing agent while ensuring the foam stability of the fire extinguishing agent. During the fire extinguishing process, the organically modified ettringite covers the surface of the burning vegetation along with the foam, expanding the coverage area and coverage density of the foam layer (ettringite absorbs water and expands, and its specific surface area is large), further improving the oxygen isolation effect of the present invention. At the same time, the polyphenol structure of tannic acid can also capture free radicals, blocking combustion, and improving the fire extinguishing efficiency of the present invention. During the fire extinguishing process, the ettringite dehydrates and absorbs heat in a high-temperature environment, further reducing the combustion temperature of the vegetation, improving the efficiency of fire extinguishing and cooling, and preventing re-ignition.

[0021] Furthermore, the foaming agent is composed of animal protein gelatin powder and lauroyl diethanolamine in a mass ratio of 1:(5-8). The present invention selects a combination of animal protein gelatin powder and lauroyl diethanolamine in an appropriate ratio as the foaming agent. While ensuring the environmental protection of the raw materials, the present invention can produce a stable foam layer even with a high inorganic component content and achieve high foaming efficiency. The foaming agent and foam stabilizer work synergistically to ensure the stability of the foam, making it less prone to rupture. During the fire extinguishing process, the foam layer covers the surface of the burning object and isolates it from oxygen.

[0022] Furthermore, the foam stabilizer is any one or more of coconut oil fatty acid diethanolamide, cetearyl glucoside, cocamidopropyl betaine, alkyl glucoside, and dodecyl dimethyl betaine.

[0023] Furthermore, the corrosion inhibitor is polyaspartic acid and / or imidazoline quaternary ammonium salt.

[0024] Furthermore, the composite flame retardant is composed of a CFA carbon former and a natural silicate-based flame retardant in a mass ratio of (1-3):1. The composite flame retardant of the present invention, which is formed by combining the CFA carbon former and the natural silicate-based flame retardant in an appropriate ratio, interacts with the organically modified ettringite and modified blast furnace slag to enhance the fire extinguishing effect and cooling rate of the present invention, significantly suppress the spread of fire, and prevent secondary re-ignition.

[0025] The present invention also provides a method for preparing a special fire extinguishing agent for forests and grasslands, which comprises the following steps:

[0026] S1. The surfactant and foaming agent were added to 2 / 3 parts by mass of water and stirred to obtain a mixture;

[0027] S2. The modified blast furnace slag was added to the mixture and stirred for 5-10min, and then the organic modified ettringite was added and stirred for 5-10min, and then the composite flame retardant and urea were added and mixed thoroughly to obtain a mixture A;

[0028] S3. Add polyethylene glycol and a corrosion inhibitor to the mixture A and stir to obtain a mixture B;

[0029] S4. Add the foam stabilizer and the remaining water to the above mixture B and stir evenly to obtain a special fire extinguishing agent for forests and grasslands.

[0030] The present invention has achieved the following beneficial effects:

[0031] 1. The fire extinguishing agent of the present invention is a bio-based foam fire extinguishing agent formed by components such as surfactant, modified blast furnace slag, foaming agent, foam stabilizer, organic modified ettringite, polyethylene glycol, urea, etc., adopting modified blast furnace slag, organic modified ettringite and foam layer to synergistically extinguish fire, so that the present invention can quickly extinguish fire and cool down in the early stage of fire, prevent the spread of fire, and can continue to cool down for a long time, absorb heat, form a protective layer on the surface of burning vegetation, isolate oxygen, block combustion, and suppress the temperature rise and rekindle of the combustion object. Selecting the surfactant, foaming agent and foam stabilizer of the present invention can ensure that the fire extinguishing agent of the present invention can quickly foam, form a stable foam layer, extend the stable duration of foam, can quickly extinguish fire, and enhance fire extinguishing efficiency. The addition of modified blast furnace slag can not only effectively and reasonably utilize production waste residue, protect the environment, provide nutrients and a good soil environment for the recovery of the ecological environment after the fire, but also form a coating layer on the combustion surface, play the role of isolating oxygen, achieve the purpose of rapid fire extinguishing and cooling, and prevent flame retardancy. The addition of organically modified calcium aluminate increases the specific surface area of the fire extinguishing agent, increases the coverage area of the present invention, improves the fire extinguishing and cooling rate, and prevents the spread of fire and re-ignition. The addition of a composite flame retardant can promote carbonization during the combustion process, forming a porous carbon layer, avoiding the spread of fire, lowering the temperature, and improving the fire extinguishing and flame retardant smoke suppression effects of the present invention. The addition of polyethylene glycol lowers the freezing point of the fire extinguishing agent of the present invention, making the present invention applicable to forest and grassland fires in cold regions. The addition of urea not only improves the flame retardant fire extinguishing efficiency and cold resistance of the present invention, but also prolongs the stability time of the foam, prevents the foam from bursting, and further enhances the fire extinguishing effect of the present invention.

[0032] 2. The raw materials of the fire extinguishing agent of the present invention are environmentally friendly, degradable and non-corrosive, which reduces the corrosion and damage to transportation instruments, foaming equipment and fire-fighting facilities, and ensures the rapid recovery of the ecological environment after the disaster.

[0033] 3. The fire extinguishing agent of the present invention has a simple processing technology, and the components interact with each other, having the dual effects of cooling and extinguishing fire. It can not only quickly prevent the spread of flammable fires, but also suppress the resurgence of smoldering fires. At the same time, the fire extinguishing agent is easy to store and transport, and is suitable for solving fire safety problems in natural disasters such as forests and grasslands. DETAILED DESCRIPTION

[0034] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0035] The forest and grassland special fire extinguishing agent of the present invention is described below with reference to specific embodiments.

[0036] Example 1

[0037] A preparation method of a special fire extinguishing agent for forests and grasslands comprises the following steps: adding 2 parts of α-sulfo fatty acid methyl ester (Wilma MES) and 1.6 parts of a foaming agent to 40 parts of water, stirring evenly to obtain a mixed solution; adding 12 parts of modified blast furnace slag to the mixed solution, stirring at a rate of 1200 rpm for 5 minutes, then adding 15 parts of organically modified calcium aluminate, stirring at a rate of 1200 rpm for 10 minutes, then adding 4.8 parts of a composite flame retardant and 2.4 parts of urea, mixing thoroughly, then adding 6.5 parts of PEG200 and 0.5 parts of polyaspartic acid (Bangpu Chemical BP-8W02), stirring evenly, and finally adding 0.8 parts of coconut oil fatty acid diethanolamide (Rui Lin 6501) and 20 parts of water, stirring evenly to obtain a special fire extinguishing agent for forests and grasslands.

[0038] The foaming agent is composed of animal protein gelatin powder (Hongcai HC-852) and lauroyl diethanolamide in a mass ratio of 1:8.

[0039] The preparation method of the modified blast furnace slag is as follows:

[0040] P1. Take an appropriate amount of blast furnace slag and immerse it in 0.01 mol / L hydrochloric acid solution. Stir at 420 rpm for 3 hours. Filter, wash with deionized water three times, dry at 110°C for 4 hours, grind, and sieve through 200 mesh to obtain acid-washed blast furnace slag.

[0041] P2. Add the above-mentioned acid-washed blast furnace slag to 0.1 mol / L sodium hydroxide solution, adjust the pH value to 10, stir and react at 420 rpm for 2 h, filter, wash with water until neutral, and dry at 110°C for 4 h to obtain pretreated blast furnace slag.

[0042] P3. By mass, 100 parts of pretreated blast furnace slag and 8 parts of ammonium polyphosphate were added to 500 parts of water, and ultrasonically treated for 30 minutes. Then, 8 parts of carboxymethyl cellulose were added, and ultrasonicated at 50°C for 30 minutes. 0.1 mol / L sodium hydroxide solution was added to adjust the pH value to 8. The mixture was stirred and reacted at 80°C for 4 hours. The mixture was filtered, and the precipitate was washed with water until neutral. The mixture was dried at 110°C for 4 hours, ground, and sieved through 400 mesh to obtain modified blast furnace slag.

[0043] The preparation method of the above-mentioned organically modified ettringite is as follows: acetic acid solution is added to a 5wt% tannic acid solution to adjust the pH value to 4, and then the dried ettringite is added, stirred and reacted at room temperature for 4 hours, filtered, washed with deionized water three times, dried at 60°C in a vacuum for 2 hours, and ground and sieved through 400 mesh to obtain the organically modified ettringite.

[0044] The composite flame retardant is composed of a CFA carbonizing agent (selected from Tangyi Chemical) and a natural silicate-based flame retardant (Tolsa) in a mass ratio of 1:1. Clay 80T).

[0045] Example 2

[0046] A preparation method of a special fire extinguishing agent for forests and grasslands comprises the following steps: adding 6 parts by mass of sodium salt of dioctyl sulfosuccinate (selected from Haian Petrochemical) and 3.6 parts of a foaming agent to 45 parts of water and stirring uniformly to obtain a mixed solution; adding 32 parts of modified blast furnace slag to the mixed solution and stirring at a speed of 1200 rpm for 10 minutes; then adding 10 parts of organically modified calcium aluminate and stirring at a speed of 1200 rpm for 8 minutes; then adding 3 parts of a composite flame retardant and 6 parts of urea and mixing thoroughly; adding 3.0 parts of PEG200 and 1.0 part of imidazoline quaternary ammonium salt YTY-05 and stirring uniformly; and finally adding 2.0 parts of cetearyl glucoside (selected from Chengtian Fine Chemicals) and 20 parts of water and stirring uniformly to obtain the special fire extinguishing agent for forests and grasslands.

[0047] The foaming agent is composed of animal protein gelatin powder (Hongcai HC-852) and lauroyl diethanolamide in a mass ratio of 1:5.

[0048] The preparation method of the modified blast furnace slag is as follows:

[0049] P1. Take an appropriate amount of blast furnace slag and immerse it in 0.01 mol / L hydrochloric acid solution. Stir at 420 rpm for 3 hours. Filter, wash with deionized water three times, dry at 110°C for 4 hours, grind, and sieve through 200 mesh to obtain acid-washed blast furnace slag.

[0050] P2. Add the above-mentioned acid-washed blast furnace slag to 0.1 mol / L sodium hydroxide solution, adjust the pH to 10, and stir at 420 rpm for 2 h. Filter, wash with water until neutral, and dry at 110°C for 4 h to obtain pretreated blast furnace slag.

[0051] P3. By mass, 100 parts of pretreated blast furnace slag and 10 parts of ammonium polyphosphate were added to 500 parts of water, and ultrasonically treated for 30 minutes. Then, 4 parts of carboxymethyl cellulose were added, and ultrasonicated at 50°C for 30 minutes. 0.1 mol / L sodium hydroxide solution was added to adjust the pH value to 8. The mixture was stirred and reacted at 80°C for 4 hours. The mixture was filtered, and the precipitate was washed with water until neutral. The mixture was dried at 110°C for 4 hours, ground, and sieved through 400 mesh to obtain modified blast furnace slag.

[0052] The preparation method of the above-mentioned organically modified ettringite is as follows: acetic acid solution is added to a 3wt% tannic acid solution to adjust the pH value to 4, and then the dried ettringite is added, stirred and reacted at room temperature for 4 hours, filtered, washed with deionized water three times, dried at 60°C in a vacuum for 2 hours, and ground and sieved through 400 mesh to obtain the organically modified ettringite.

[0053] The composite flame retardant is composed of a CFA carbonizing agent (selected from Tangyi Chemical) and a natural silicate-based flame retardant (Tolsa) with a mass ratio of 3:1. Clay 80T).

[0054] Example 3

[0055] A preparation method of a special fire extinguishing agent for forests and grasslands comprises the following steps: adding 5.6 parts of sodium lauroyl isethionate (selected from Kandis Chemical) and 3.2 parts of a foaming agent to 48 parts of water, stirring evenly to obtain a mixed solution; adding 26 parts of modified blast furnace slag to the mixed solution, stirring at a speed of 1200 rpm for 8 minutes, then adding 11 parts of organically modified calcium aluminate, stirring at a speed of 1200 rpm for 8 minutes, then adding 4.2 parts of a composite flame retardant and 5.5 parts of urea, stirring evenly, adding 5.8 parts of PEG200 and 0.8 parts of imidazoline quaternary ammonium salt YTY-05, stirring evenly, and finally adding 1.6 parts of cocamidopropyl betaine (selected from CAB-35 of Runtec) and 24 parts of water, stirring evenly to obtain a special fire extinguishing agent for forests and grasslands.

[0056] The foaming agent is composed of animal protein gelatin powder (Hongcai HC-852) and lauroyl diethanolamide in a mass ratio of 1:7.

[0057] The preparation method of the modified blast furnace slag is as follows:

[0058] P1. Take an appropriate amount of blast furnace slag and immerse it in 0.01 mol / L hydrochloric acid solution. Stir at 420 rpm for 3 hours. Filter, wash with deionized water three times, dry at 110°C for 4 hours, grind, and sieve through 200 mesh to obtain acid-washed blast furnace slag.

[0059] P2. Add the above-mentioned acid-washed blast furnace slag to 0.1 mol / L sodium hydroxide solution, adjust the pH to 10, and stir at 420 rpm for 2 h. Filter, wash with water until neutral, and dry at 110°C for 4 h to obtain pretreated blast furnace slag.

[0060] P3. By mass, 100 parts of pretreated blast furnace slag and 8 parts of ammonium polyphosphate were added to 500 parts of water, and ultrasonically treated for 30 minutes. Then, 7 parts of carboxymethyl cellulose were added, and ultrasonicated at 50°C for 30 minutes. 0.1 mol / L sodium hydroxide solution was added to adjust the pH value to 8. The mixture was stirred and reacted at 80°C for 4 hours. The mixture was filtered, and the precipitate was washed with water until neutral. The mixture was dried at 110°C for 4 hours, ground, and sieved through 400 mesh to obtain modified blast furnace slag.

[0061] The preparation method of the above-mentioned organically modified ettringite is as follows: acetic acid solution is added to a 6wt% tannic acid solution to adjust the pH value to 4, and then the dried ettringite is added, stirred and reacted at room temperature for 4 hours, filtered, washed with deionized water three times, dried at 60°C in a vacuum for 2 hours, and ground and sieved through 400 mesh to obtain the organically modified ettringite.

[0062] The composite flame retardant is composed of a CFA carbonizing agent (selected from Tangyi Chemical) and a natural silicate-based flame retardant (Tolsa) with a mass ratio of 2:1. Clay 80T).

[0063] Example 4

[0064] A preparation method of a special fire extinguishing agent for forests and grasslands is as follows: 4.5 parts of calcium lignin sulfonate (selected from Shandong Polychemical) and 2.5 parts of foaming agent are added to 54 parts of water, stirred evenly, to obtain a mixed solution; 22 parts of modified blast furnace slag are added to the mixed solution, stirred at a speed of 1200 rpm for 10 minutes, and then 12.8 parts of organic modified calcium aluminate are added, stirred at a speed of 1200 rpm for 10 minutes, and then 3.0 parts of composite flame retardant and 7.5 parts of urea are added and mixed thoroughly, 2.6 parts of PEG200 and 0.7 parts of polyaspartic acid (Bangpu Chemical BP-8W02) are added, stirred evenly, and finally 1.2 parts of alkyl glycoside (selected from Hongwang Chemical) and 26 parts of water are added and stirred evenly to obtain a special fire extinguishing agent for forests and grasslands.

[0065] The components and preparation methods of the foaming agent, modified blast furnace slag, organic modified ettringite and composite flame retardant are the same as those in Example 3, and specific reference is made to Example 3.

[0066] Comparative Example 1

[0067] The raw materials, preparation method, etc. of the special fire extinguishing agent for forests and grasslands in this comparative example 1 are the same as those in Example 4, except that modified blast furnace slag is not added in this comparative example 1.

[0068] Comparative Example 2

[0069] The raw materials, preparation method, etc. of the special fire extinguishing agent for forests and grasslands in this comparative example 2 are the same as those in Example 4. The difference is that the blast furnace slag in this comparative example 2 is not modified with ammonium polyphosphate and carboxymethyl fiber, that is, the blast furnace slag added is pretreated blast furnace slag obtained by steps P1 and P2.

[0070] Comparative Example 3

[0071] The raw materials, preparation method, etc. of the special fire extinguishing agent for forests and grasslands in this comparative example 3 are the same as those in Example 4. The difference is that ammonium polyphosphate is not added to the modified blast furnace slag in this comparative example 3 for modification, and the other steps are the same.

[0072] Comparative Example 4

[0073] The raw materials, preparation method, etc. of the special fire extinguishing agent for forest and grassland in this comparative example 4 are the same as those in Example 4. The difference is that step P3 of the preparation method of modified blast furnace slag in this comparative example 4 is: add 100 parts of pretreated blast furnace slag and 8 parts of ammonium polyphosphate to 500 parts of water, by mass, ultrasonicate at 50°C for 30 minutes, add 0.1 mol / L sodium hydroxide solution to adjust the pH value to 8, stir and react at 80°C for 4 hours, filter, wash the precipitate with water until it is neutral, dry at 110°C for 4 hours, grind, and sieve through 400 mesh to obtain modified blast furnace slag.

[0074] Comparative Example 5

[0075] The raw materials, preparation method, etc. of the special fire extinguishing agent for forests and grasslands in this comparative example 5 are the same as those in Example 4. The difference is that the organic modified ettringite in this comparative example 5 is organosilane modified ettringite, and its preparation method is: adding dry ettringite to the hydrolyzed organosilicon coupling agent solution (KH-550, ethanol and deionized water in a mass ratio of 1:5:2, pH value 4), stirring at 80°C for 4h, centrifuging, washing with ethanol 3 times, vacuum drying at 60°C, grinding and sieving 400 mesh, to obtain.

[0076] Comparative Example 6

[0077] The raw materials, preparation method, etc. of the special fire extinguishing agent for forests and grasslands in Comparative Example 6 are the same as those in Example 4, except that organically modified ettringite is not added in Comparative Example 6.

[0078] Comparative Example 7

[0079] The raw materials, preparation method, etc. of the special fire extinguishing agent for forests and grasslands in this comparative example 7 are the same as those in Example 4, except that the foaming agent in this comparative example 7 is animal protein gelatin powder.

[0080] Comparative Example 8

[0081] The raw materials, preparation method, etc. of the special fire extinguishing agent for forests and grasslands in this comparative example 8 are the same as those in Example 4, except that no natural silicate-based flame retardant is added to the composite flame retardant in this comparative example 8.

[0082] The foaming performance, fire extinguishing performance and anti-reignition performance of the forest and grassland special fire extinguishing agents prepared in Examples 1-4 and Comparative Examples 1-8 were tested, and the test results are shown in Table 1 below.

[0083] The foaming performance is tested according to the national standards GB15308-2006 "Foam Fire Extinguishing Agent" and GB27897-2011 "Class A Foam Fire Extinguishing Agent".

[0084] Fire extinguishing performance test:

[0085] (1) Wood strips, specifications: square cross-section, side length 40 mm, wood strip length 640 mm. Number of wood strips: 112. Moisture content of wood strips <10%.

[0086] (2) Wood strips are stacked on metal supports, with 7 strips per layer. The adjacent layers of wood strips are stacked vertically, with a total of 16 layers. The distance between adjacent wood strips in each layer is 60 mm.

[0087] (3) The ignition agent is 1500ml of No. 120 solvent oil, placed in a square metal tray with a side length smaller than the side length of the woodpile. Add 30mm of water to the tray. Ignite the solvent oil and remove the tray after it burns out.

[0088] (4) After the wood pile is ignited, it burns freely. When the mass power is reduced to 53% of the original mass, the pre-combustion ends.

[0089] (5) Use a 6.6L fire extinguisher filled with a forest and grassland fire extinguishing agent diluted 30 times with water. Open the spray valve 1.8 meters away from the woodpile to spray and extinguish the fire. Move closer to the woodpile while spraying, and spray the fire extinguishing agent from the top, bottom, and sides of the woodpile.

[0090] Prepare 12 identical wood piles as described above, and use the forest and grassland special fire extinguishing agents of the above-mentioned Examples 1-4 and Comparative Examples 1-8 to conduct fire extinguishing tests on each wood pile. The experimental results are as follows: when the forest fire extinguishing agent is sprayed until the flames of the wood pile are extinguished, record the fire extinguishing time; if the fire extinguishing is completed, stop applying the fire extinguishing agent 10 minutes after and observe whether it re-ignites.

[0091] Table 1 Performance test results of forest and grassland special fire extinguishing agents

[0092]

[0093]

[0094] As can be seen from the test results in Table 1 above, the forest and grassland fire extinguishing agent of the present invention has a high foaming multiple, stable foam, fast fire extinguishing speed, and is not easy to reignite. As can be seen from Comparative Examples 1-4, the addition of modified blast furnace slag significantly improves the fire extinguishing effect of the fire extinguishing agent of the present invention and prevents the possibility of reignition. However, blast furnace slag has a certain impact on foaming performance. By modifying blast furnace slag according to the present invention, the foam stability of the fire extinguishing agent of the present invention can be ensured, thereby improving the fire extinguishing efficiency of the present invention.

[0095] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0096] The above embodiments merely illustrate several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the scope of the present invention, all of which fall within the scope of protection of the present invention.

Claims

1. A special fire extinguishing agent for forests and grasslands, characterized in that: The invention comprises the following components in parts by weight: 2-6 parts of surfactant, 10-35 parts of modified blast furnace slag, 10-15 parts of organic modified ettringite, 0.5-4 parts of foaming agent, 0.5-2 parts of foam stabilizer, 0-10 parts of polyethylene glycol, 0-10 parts of urea, 0.5-1.0 parts of corrosion inhibitor, 3-5 parts of composite flame retardant and 50-80 parts of water; The modified blast furnace slag is prepared by modifying the acid- and alkali-treated blast furnace slag using carboxymethyl cellulose.

2. The forest and grassland special fire extinguishing agent according to claim 1, characterized in that: The preparation method of the modified blast furnace slag is: P1. Place the blast furnace slag in a 0.01 mol / L hydrochloric acid solution, stir for 2-3 hours, filter, repeatedly wash with water, dry, grind, and sieve through 200 mesh to obtain acid-washed blast furnace slag; P2. The pickled blast furnace slag was added to a sodium hydroxide solution, the pH value was adjusted to 10-12, the reaction was stirred for 1-2h, filtered, washed with water until neutral, and dried to obtain pretreated blast furnace slag; P3. Add pretreated blast furnace slag and ammonium polyphosphate to an appropriate amount of water, ultrasonically treat for 20-30 minutes, then add carboxymethyl cellulose, ultrasonicate at 50-60℃ for 30 minutes, add sodium hydroxide solution to adjust the pH value to 8, stir and react at 70-80℃ for 2-4 hours, filter, wash the precipitate with water until it is neutral, dry, grind, and sieve through 400 mesh to obtain modified blast furnace slag.

3. The forest-grassland special fire extinguishing agent according to claim 2, characterized in that: The concentration of the sodium hydroxide solution is 0.1-1.0 mol / L; The amount of ammonium polyphosphate added is 5-10% of the mass of the pretreated blast furnace slag; The added amount of the carboxymethyl cellulose is 4-8% of the mass of the pretreated blast furnace slag.

4. The forest and grassland special fire extinguishing agent according to claim 1, characterized in that: The surfactant is any one or more of lignin sulfonate, succinate sulfonate, alkyl glyceryl ether sulfonate, sodium lauroyl isethionate, α-sulfo fatty acid methyl ester, and linear alkylbenzene sulfonate.

5. The forest and grassland special fire extinguishing agent according to claim 1, characterized in that: The preparation method of the organic modified ettringite comprises the following steps: adding an acetic acid solution to a 3-6 wt% tannic acid solution to adjust the pH value to 4-5, then adding the dried ettringite, stirring and reacting at room temperature for 3-5 hours, filtering, washing with deionized water, and vacuum drying to obtain the organic modified ettringite.

6. The forest and grassland special fire extinguishing agent according to claim 1, characterized in that: The foaming agent is composed of animal protein gelatin powder and lauroyl diethanolamine in a mass ratio of 1:(5-8).

7. The forest and grassland special fire extinguishing agent according to claim 1, characterized in that: The foam stabilizer is any one or more of coconut oil fatty acid diethanolamide, cetearyl glucoside, cocamidopropyl betaine, alkyl glucoside, and dodecyl dimethyl betaine.

8. The forest and grassland special fire extinguishing agent according to claim 1, characterized in that: The corrosion inhibitor is polyaspartic acid and / or imidazoline quaternary ammonium salt.

9. The forest and grassland special fire extinguishing agent according to claim 1, characterized in that: The composite flame retardant is composed of a CFA carbon former and a natural silicate-based flame retardant in a mass ratio of (1-3):

1.

10. A method for preparing the special fire extinguishing agent for forests and grasslands according to any one of claims 1 to 9, characterized in that: The specific steps are: S1. The surfactant and foaming agent were added to 2 / 3 parts by mass of water and stirred to obtain a mixture; S2. The modified blast furnace slag was added to the mixture and stirred for 5-10min, and then the organic modified ettringite was added and stirred for 5-10min, and then the composite flame retardant and urea were added and mixed thoroughly to obtain a mixture A; S3. Add polyethylene glycol and a corrosion inhibitor to the mixture A and stir to obtain a mixture B; S4. Add the foam stabilizer and the remaining water to the above mixture B and stir evenly to obtain a special fire extinguishing agent for forests and grasslands.

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