Fire extinguishing material prepared from calcium sulfate dihydrate, fire extinguishing agent containing same and application of fire extinguishing material

Abstract

The invention belongs to the technical field of fire extinguishing material preparation, and relates to a fire extinguishing material prepared from calcium sulfate dihydrate, a fire extinguishing agent containing the fire extinguishing material and application. The technical key points are as follows: solid waste containing calcium sulfate dihydrate is processed into powder with the particle diameter below 250 microns at the temperature of 50-70 DEG C, the powder is used as a first fire extinguishing material, and the content of calcium sulfate is greater than or equal to 80%; the solid waste is one or more of natural gypsum ore, phosphorite tailings or ardealite or desulfurized gypsum generated in the fire coal desulfurization process. The novel dry powder extinguishing agent is prepared by taking calcium sulfate dihydrate as a formula main material, adding proper water content regulator, ingredients and fire extinguishing performance enhancer and performing surface modification treatment, extinguishes fire mainly by physical action, can effectively inhibit generation of toxic smoke, and is obvious in cost advantage, wide in application range and suitable for industrial production. And meanwhile, the recycling value of solid wastes can be expanded.

Description

Technical Field

[0001] The invention belongs to the technical field of fire extinguishing material preparation, and relates to a fire extinguishing material prepared from calcium sulfate dihydrate, a fire extinguishing agent containing the fire extinguishing material, and applications thereof. Background Art

[0002] At present, phosphate tailings and coal desulfurization will generate a large amount of solid waste, the main component of which is calcium sulfate dihydrate, commonly known as phosphogypsum and desulfurized gypsum, which is usually used as building materials. However, with the sluggish construction market for a considerable period of time in the future and the sharp drop in the use of building materials, it will inevitably cause a large amount of such waste to accumulate, which will be difficult to handle, occupy land, affect the environment, and may cause secondary disasters such as landslides and mud-rock flows.

[0003] At present, the most widely used fire extinguishing agent in the market is dry powder fire extinguishing agent, with a domestic market size of 50 million tons / year, mainly including BC and ABC. The former uses sodium bicarbonate as the main ingredient, with a price of about 3,000 yuan per ton, and the latter uses diammonium phosphate / ammonium sulfate as the main ingredients, with a price of about 6,000 yuan per ton. The two types of dry powder fire extinguishing agents have occupied the market for nearly a hundred years, and the production enterprises have been engaged in long-term homogeneous competition, resulting in a market product qualification rate of less than 40%; BC fire extinguishing agent is suitable for extinguishing liquid and gas fires; ABC fire extinguishing agent is suitable for extinguishing solid, liquid, and gas fires, but the cooling effect of the fire extinguishing process is poor and it is easy to rekindle; in addition to dry powder, existing fire extinguishing agents also include water-based, foam, gas, liquid, aerosol and other types, but they are all designed based on initial fires in small indoor spaces, and are powerless in the event of large-scale outdoor fires; there is currently no suitable fire extinguishing agent for typical forest fires and new energy battery fires. Summary of the invention

[0004] The purpose of the present invention is to overcome the defects of the prior art and provide a fire extinguishing material prepared from calcium sulfate dihydrate and a fire extinguishing agent and application thereof, which utilizes solid waste gypsum, including phosphogypsum and desulfurized gypsum and gypsum produced by recycling other wastes as the main raw material, adds appropriate ingredients, and undergoes a series of processes to make a series of products suitable for different needs, so as to solve the problem that the current fire extinguishing agent is high in cost and not suitable for large-scale fire fighting, and the problem that the current dry powder fire extinguishing agent is easy to reignite after extinguishing solid fires.

[0005] The above technical objectives of the present invention are achieved through the following technical solutions:

[0006] The present invention provides a fire extinguishing material prepared from calcium sulfate dihydrate, wherein solid waste containing calcium sulfate dihydrate is processed at 50-70° C. into powder with a particle diameter of less than 250 μm as a first fire extinguishing material, wherein the content of calcium sulfate is ≥80%;

[0007] The solid waste is one or more of natural gypsum mines, phosphate ore tailings, phosphogypsum or desulfurized gypsum produced during coal desulfurization.

[0008] Furthermore, when the water content of the first fire extinguishing material is less than a set threshold, a water content regulator is used to mix with the first fire extinguishing material so that the water content of the mixture is greater than or equal to the threshold, and the obtained mixture is the second fire extinguishing material.

[0009] Note: The water content mentioned here mainly refers to the crystallization water content, and also includes a small amount of adsorbed water content; the water content regulator is one or more of magnesium sulfate heptahydrate, calcium chloride hexahydrate or aluminum alum. The crystallization water accounts for a higher proportion in the molecular structure of these three compounds, and the crystallization water content can be increased after adding. However, if one or more of these three are used as fire extinguishing materials alone, they are easy to agglomerate and cannot remain in a dry and loose state for a long time, so they cannot be sprayed for fire extinguishing.

[0010] Furthermore, the first fire extinguishing material or the second fire extinguishing material is screened into five components with different particle sizes: ① below 20 μm; ② 20-40 μm; ③ 40-63 μm; ④ 63-125 μm; ⑤ 125-250 μm, and each component with a particle size is the third fire extinguishing material.

[0011] Furthermore, the third fire extinguishing materials with different particle sizes are mixed according to grading to obtain the fourth fire extinguishing material.

[0012] Furthermore, ingredients with particle diameters less than 20 μm are added to the fourth fire extinguishing material and mixed evenly to obtain a fifth fire extinguishing material; the ingredients are one or more of fly ash, wood ash or soil from the old Yellow River course.

[0013] Note: Adding ingredients here can keep the fire extinguishing materials in a dry and loose state for a longer period of time without agglomeration, thus achieving a better fire extinguishing effect.

[0014] The present invention also provides a method for preparing a fire extinguishing agent using calcium sulfate dihydrate as a main material, wherein the fifth fire extinguishing material is surface-modified using a surfactant to obtain a first fire extinguishing agent.

[0015] The surfactant here refers to one or more of methoxy silicone oil, hydrogen silicone oil or fluorocarbon silicone oil, and the added amount is 0.5-2.5%.

[0016] The surface modification method mainly involves controlling the temperature at 50-70°C and stirring at high speed.

[0017] Furthermore, a fire extinguishing performance enhancer is used to enhance the fire extinguishing performance of the first fire extinguishing agent to obtain a second fire extinguishing agent.

[0018] The fire extinguishing performance enhancer is one or both of hydrated magnesium acetate and carbonamide.

[0019] The present invention also provides the use of the fire extinguishing material and the fire extinguishing agent, wherein the first fire extinguishing agent and the second fire extinguishing agent are used for portable dry powder fire extinguishers, automatic dry powder fire extinguishing systems or for making fire extinguishing bombs;

[0020] The third fire extinguishing material, the fourth fire extinguishing material, and the fifth fire extinguishing material are used for large-scale fire fighting equipment such as dry powder fire trucks, fire boats, fire helicopters, and drones;

[0021] The first fire extinguishing material and the second fire extinguishing material are used to replace dry sand for fire extinguishing, such as in laboratories, gas stations, oil depots, docks, etc.

[0022] Note: Considering the fire extinguishing performance, the first fire extinguishing agent and the second fire extinguishing agent are more suitable for fire fighting equipment; those suitable for fire fighting equipment are also more suitable for replacing dry sand fire fighting. The above graded combination is mainly based on comprehensive consideration of factors such as fire fighting cost.

[0023] In summary, the present invention has the following beneficial effects:

[0024] The present invention provides a fire extinguishing material prepared from calcium sulfate dihydrate, a fire extinguishing agent containing the same, and an application thereof. Solid waste gypsum, including phosphogypsum and desulfurized gypsum and gypsum produced by recycling other wastes, is used as a main raw material, and appropriate ingredients are added. After a series of processes, a series of products suitable for different needs are made. (1) The problem that the current fire extinguishing agent is high in cost and not suitable for large-scale fire fighting is solved; (2) The problem that the current dry powder fire extinguishing agent is easy to rekindle after extinguishing a solid fire; (3) The fire extinguishing process is mainly based on physical action, does not produce toxic chemical components, and has high environmental protection performance; (4) It can inhibit the generation of fire-toxic smoke and reduce suffocation death caused by fire smoke. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 A flow chart for preparing the fire extinguishing agent provided by the present invention;

[0026] Figure 2 The DSC curve of the raw material of step S1 of Example 1;

[0027] Figure 3 This is the thermogravimetric analysis diagram of the raw material of step S1 of Example 1;

[0028] Figure 4 The woodpile fire model used in Example 2.

[0029] Reference numerals

[0030] 1. Ignition tray; 2. Bracket; 3. Weighing platform; 4. Angle iron. DETAILED DESCRIPTION

[0031] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, a fire extinguishing material prepared by calcium sulfate dihydrate and a fire extinguishing agent and application thereof proposed by the present invention, its specific implementation method, characteristics and effects are described in detail as follows.

[0032] This specific embodiment first provides a fire extinguishing material prepared by calcium sulfate dihydrate provided by the present invention, wherein solid waste containing calcium sulfate dihydrate is processed at 50-70° C. into powder with a particle diameter of less than 250 μm as a first fire extinguishing material, wherein the content of calcium sulfate is ≥80%;

[0033] The solid waste is one or more of natural gypsum mines, phosphate ore tailings, or phosphogypsum or desulfurized gypsum produced during coal desulfurization.

[0034] As a preferred embodiment of the above embodiment, when the water content of the first fire extinguishing material is less than a set threshold, a water content regulator is used to mix and crush the first fire extinguishing material so that the water content of the mixture is greater than or equal to the threshold, and the obtained mixture is the second fire extinguishing material.

[0035] Among them, the moisture content test and adjustment includes taking the first fire extinguishing material and testing its weight loss ratio at 200°C. If the weight loss at 200°C is less than 15±1% and does not reach 15%, the moisture content is adjusted by adding a moisture content regulator. The proportion of the moisture content regulator added can be determined by theoretical calculation or based on an experimental curve until it is tested again and its water loss at 200°C reaches 20%, thereby obtaining a second fire extinguishing material.

[0036] As a preferred embodiment of the above embodiment, the first fire extinguishing material or the second fire extinguishing material is screened into five components with different particle sizes: ① below 20 μm; ② 20-40 μm; ③ 40-63 μm; ④ 63-125 μm; ⑤ 125-250 μm, and each component with different particle sizes is the third fire extinguishing material.

[0037] As a preferred embodiment of the above embodiment, the water content regulator is one or more of magnesium sulfate heptahydrate, calcium chloride hexahydrate or aluminum alum.

[0038] As a preferred embodiment of the above embodiment, the third fire extinguishing materials with different particle sizes are mixed to obtain the fourth fire extinguishing material.

[0039] As a preferred embodiment of the above embodiment, ingredients with particle diameters less than 20 μm are added to the fourth fire extinguishing material, and the mixture is mixed evenly to obtain a fifth fire extinguishing material.

[0040] Among them, the raw materials of the batching are one or more of fly ash, soil from the old Yellow River course or wood ash, and the added amount is the fourth fire extinguishing material: batching (mass ratio) 90-98:2-10.

[0041] As a preferred embodiment of the above embodiment, the ingredients are processed into powder with a particle diameter of less than 50 μm by a grinding mill. Several types of fly ash, soil from the old Yellow River course or wood ash can be selected, pre-mixed and then processed together by a grinding mill into powder with a particle diameter of less than 50 μm. Samples are taken for testing and the weight loss at 200°C reaches 1±0.5%, which is used as the ingredient.

[0042] The present invention also provides a fire extinguishing agent of a fire extinguishing material prepared from calcium sulfate dihydrate. The surface of the fifth fire extinguishing material is modified by using a surfactant to obtain a first fire extinguishing agent.

[0043] Furthermore, the surfactant is one or more of methoxy silicone oil, hydrogen silicone oil or fluorocarbon silicone oil, and the added amount is 0.5-2.5%.

[0044] The specific method of surface modification is: adding the fifth fire extinguishing material into a high-speed mixer, adjusting the speed to 240 rpm, mixing for 5 to 10 minutes, adding (by weight) 0.5 to 2.5% surfactant of the fifth fire extinguishing material in 3 times, and controlling the temperature at 40 to 70° C., adjusting the speed to 480 rpm, continuing to mix for 10 to 30 minutes, and stopping for 30 minutes when the temperature naturally drops below 30° C. to prepare the first fire extinguishing agent, which can be used as a type A dry powder fire extinguishing agent, is suitable for extinguishing Class A fires, and can be packaged.

[0045] As a preferred embodiment of the above embodiment, a fire extinguishing performance enhancer is used to enhance the fire extinguishing performance of the first fire extinguishing agent to obtain a second fire extinguishing agent.

[0046] As a preference of the above embodiment, the fire extinguishing performance enhancer is one or both of hydrated magnesium acetate or carbonamide.

[0047] The method for enhancing the fire extinguishing performance is: start the high-speed mixer, add the first fire extinguishing agent and the fire extinguishing performance enhancer, the added amount is 5-15% of the first fire extinguishing agent (weight ratio), gradually adjust the speed to 800-1200 rpm, continue for 1-5 minutes, then discharge the material, package and package to obtain the second fire extinguishing agent, which can be used as an ABC type dry powder fire extinguishing agent and is suitable for extinguishing ABC type fires.

[0048] Among them, the order can be changed and the speed of the high-speed mixer can be adjusted according to actual production needs. The rotation of the high-speed mixer, in addition to mixing the materials, can also increase the temperature. The temperature change can change the speed of the surface modification reaction.

[0049] In some preferred embodiments, the fire extinguishing agent formulation and preparation method include the following process, the flow chart is shown in Figure 1 :

[0050] 1. Preparation of main ingredient powder:

[0051] 1) Raw material selection: Desulfurized gypsum or phosphogypsum is selected as the main raw material (natural dihydrate gypsum is also acceptable);

[0052] 2) Sampling and analysis: Sampling and analysis of its chemical composition, analysis of the content of various components, when the content of calcium sulfate reaches above the set value and there are no other toxic and radioactive substances, it can be selected;

[0053] 3) Processing: Control the temperature at 50-70°C to process the raw materials into powder with a particle diameter of less than 250 μm, which is called main material powder (first fire extinguishing material);

[0054] 4) Water content test and adjustment: Take the powder sample processed in the previous step and test its weight loss ratio at 200°C. When it reaches 20±1%, it is called qualified main material powder; if the weight loss at 200°C is small, less than 19%, the water content of the main material powder can be adjusted by adding a water content regulator. The water content regulator can be one or more of magnesium sulfate heptahydrate, calcium chloride hexahydrate, and aluminum alum. The proportion of the water content regulator can be determined by theoretical calculation or experimental curve, until it is tested again and its water loss at 200°C reaches 20%, then a qualified main material powder (second fire extinguishing material) is obtained.

[0055] 5) Screening: According to different application scenarios and adaptation to different types of fire-fighting equipment and appliances, the qualified main material powder is screened into five components with different particle finenesses: ① below 20μm; ② 20-40μm; ③ 40-63μm; ④ 63-125μm; ⑤ 125-250μm, collectively referred to as qualified main material powder (third fire-fighting material).

[0056] 2. Preparation of ingredient powder:

[0057] 1) Material selection: select one or more of fly ash, soil from the old Yellow River course, and plant ash;

[0058] 2) Processing: The selected ingredients are processed into powder with a particle diameter of less than 50 μm by a grinding machine. If several ingredients are selected, they are pre-mixed and then processed into powder with a particle diameter of less than 50 μm by a grinding machine. Samples are taken for testing and the weight loss at 200°C reaches 1±0.2%, which is called qualified ingredient powder;

[0059] 3. Mixing of fire extinguishing materials: According to the needs of extinguishing different types of fires, adapting to different fire extinguishing equipment and appliances, and different shelf life needs, the qualified main ingredient powder and the qualified auxiliary ingredient powder are mixed in a certain proportion to make different grades of formulated fire extinguishing materials (the fifth fire extinguishing material).

[0060] 4. Fire extinguishing agent preparation:

[0061] 1) Selection of qualified main material powder: Select four types of qualified main material powder with particle diameters of ① 20μm or less; ② 20-40μm; ③ 40-63μm; ④ 63-125μm, mix them in a certain proportion, and they are called fire extinguishing agent main material powder (the fourth fire extinguishing material);

[0062] 2) Selection of standard batching powder: Screen the standard batching powder with particle diameter below 20μm, which is called fire extinguishing agent batching powder;

[0063] 3) Preparation of fire extinguishing agent pre-made powder: fully mix the fire extinguishing agent main material powder and the fire extinguishing agent batching powder in a ratio of 90-98%:2-10% to obtain the fire extinguishing agent pre-made powder;

[0064] 4) Surfactant selection: one or more of methoxy silicone oil, hydrogen silicone oil, and fluorocarbon silicone oil can be selected as the surfactant, and the addition amount is 0.5-2.5%;

[0065] 5) Selection of fire extinguishing performance enhancer: it can be one or both of hydrated magnesium acetate and carbonamide;

[0066] 6) Surface modification treatment: add the fire extinguishing agent pre-powder to a high-speed mixer, adjust the speed to 240 rpm, mix for 5 to 10 minutes, add (by weight) 0.5 to 2.5% surfactant of the total amount of the fire extinguishing agent pre-powder in 3 times, control the temperature at 40 to 80° C., adjust the speed to 480 rpm, continue mixing for 10 to 30 minutes, wait for the temperature to naturally drop below 30° C., stop for 30 minutes, and prepare a type A dry powder fire extinguishing agent (the first fire extinguishing agent), which is suitable for extinguishing Class A fires and can be packaged;

[0067] 7) Fire extinguishing performance enhancement treatment: Continue with the previous step, start the high-speed mixer again, add the fire extinguishing performance enhancer, add 5-15% and gradually adjust the speed to 800-1200 rpm for 1-5 minutes, then discharge the material, package and encapsulate it to make ABC type dry powder fire extinguishing agent (second fire extinguishing agent), which is suitable for extinguishing ABC fires;

[0068] Here, steps 6) and 7) can be changed in order and the speed of the high-speed mixer can be adjusted according to actual production needs. The rotation of the high-speed mixer can not only mix the materials, but also increase the temperature. The temperature change can change the speed of the surface modification reaction.

[0069] This specific embodiment also provides the use of the above-mentioned fire extinguishing materials and fire extinguishing agents, wherein the first fire extinguishing agent and the second fire extinguishing agent are used for filling a portable dry powder fire extinguisher, an automatic dry powder fire extinguishing system or preparing a fire extinguishing bomb;

[0070] The third fire extinguishing material, the fourth fire extinguishing material, and the fifth fire extinguishing material are used for large-scale fire fighting equipment such as dry powder fire trucks, fire boats, drones, and helicopters;

[0071] The first fire extinguishing material and the second fire extinguishing material are used to replace dry sand for fire extinguishing, such as in laboratories, gas stations, oil depots, docks, etc.

[0072] Considering the fire extinguishing performance, the first fire extinguishing agent and the second fire extinguishing agent are more suitable for fire fighting equipment; those suitable for fire fighting equipment are also more suitable for replacing dry sand fire fighting. If factors such as fire fighting cost are comprehensively considered, the above graded combination is adopted.

[0073] Example 1

[0074] After roughly selecting the source of goods, through the test report of the environmental protection department on the desulfurization gypsum of a thermal power plant, it was learned that the calcium sulfate content of the coal-fired desulfurization gypsum produced by a thermal power plant was greater than 93% (dry weight), and there was no radioactivity and other harmful substances, so it was determined that it could be used as raw material.

[0075] By sampling the crystal water content of desulfurized gypsum, since most of the desulfurized gypsum in thermal power plants is piled up in the open air, the crystal water content of different manufacturers is different. The water content of the surface and deep layers is different, which can be divided into adsorbed water and crystal water. The deep layer has more adsorbed water. Therefore, a small Luoyang shovel is used to select 5 different points from the surface and deep layers to take samples and mix them. Then 200g is weighed, and the negative pressure of 0.05Mpa at 50-70℃ is controlled to remove water for 30-60 minutes. The weight G is measured with a 0.2g sensitive balance, and then the sample is placed in an electric oven, the temperature is adjusted to 200-250℃, and dried for 50-60 minutes. The weight G1 is measured again, and the weight loss G2 is calculated:

[0076] G2 = G-G1, where the weight loss is regarded as the crystal water content;

[0077] Calculate the percentage of crystal water: H2O% = G2 / G·100%;

[0078] The proportion of crystal water H2O% reaches 15±0.2%, which can determine that the desulfurization gypsum of this plant can be processed according to the following steps.

[0079] S1. A horizontal impact mill or a jet mill is used to control the temperature at 60°C and add 1 / 5 to 1 / 6 of the weight of magnesium sulfate heptahydrate to the raw material to process it into a powder with a particle diameter of less than 125 μm to obtain a second fire extinguishing material, and the powder is sieved into four different particle sizes: less than 20 μm; 20 to 40 μm; 40-63 μm; and 63 to 125 μm to obtain a third fire extinguishing material;

[0080] S2. Add the powders of the above fineness into a mixer in a ratio of 2:3:3:2 to obtain a fourth fire extinguishing material;

[0081] S3, selecting fly ash and plant ash as batching raw materials, and processing the selected batching raw materials into powder with a particle diameter of less than 40 μm by impact grinding to obtain batching powder;

[0082] S4, add the fourth fire extinguishing material to the high-speed mixer in a ratio of 90:10 (mass ratio), gradually adjust the speed to 1200 rpm, control the temperature not to exceed 70°C, mix for 15 minutes, stop, and cool naturally to obtain the first fire extinguishing agent;

[0083] S5, Packaging: When the temperature drops below 30℃, unload the material, pack and package.

[0084] The above method is used to prepare a dry powder fire extinguishing agent suitable for extinguishing Class A fires, and is also applicable to Class C and E fires.

[0085] The raw materials used in step S1 were subjected to DSC and TG tests. The test results are shown in Figure 2 and Figure 3 .

[0086] in, Figure 2 The horizontal axis is temperature (℃), and the vertical axis is heat flow signal (mW); Onset (starting temperature): 136.95℃; Peak (peak temperature): 151.41℃; Endset (end temperature): 161.28℃; Integra1 (integral value): -1441.29mJ (representing the total energy of thermal effect). It can be seen from the figure that the raw material loses water near 156.41℃ and is accompanied by a strong endothermic effect, indicating that it can absorb the heat of the flame and reduce the surrounding temperature; gaseous water molecules are formed during the dehydration process to isolate oxygen, and no heat release is observed in the figure.

[0087] Figure 3 The horizontal axis is temperature (℃), and the vertical axis is mass (mg). Figure 2 It can be seen that the corresponding temperature range before and after its weight loss (decomposition and loss of crystal water) shows that the raw material has high thermal stability and is more suitable as a base material for fire extinguishing agents because it only loses crystal water without producing other complex chemical reactions and releasing crystal water to absorb heat.

[0088] Example 2

[0089] (1) Two 3kg dry powder fire extinguishers are selected, numbered 1# and 2#. Other specifications are as follows: nozzle diameter φ4mm, nozzle inner diameter φ10mm, nozzle length 400mm, cylinder diameter φ127.4mm, cylinder volume 3.8L, siphon inner diameter φ12mm, distance between siphon and cylinder bottom 13mm~16mm, and materials and strength shall comply with the provisions of GB 4351-2023.

[0090] (2) Fire extinguisher filling: Weigh 3.0±0.1 kg of the first fire extinguishing agent prepared in Example 1, add it to the 1# and 2# fire extinguishers selected in the previous step, and fill them with nitrogen, with an initial pressure of (1.2±0.1) MPa (gauge pressure).

[0091] (3) Test model preparation

[0092] Select larch wood, after treatment, its moisture content is 10% to 14% (mass fraction), density is 0.5g / cm 3 The cross section of the wood strip is square, the side length is 39mm±1mm, the length of the wood strip is 635±10mm, and there are 7 strips in each layer of 16 layers (such as Figure 4 ).

[0093] (4) Test steps (see GB4066-2017):

[0094] Ignite the wood, use 500mL of paint thinner for decoration engineering, pour it into the ignition tray just below the wood pile, ignite it, and when it burns out, remove the ignition tray;

[0095] Fire extinguishing: When the woodpile has burned to the point where its mass is reduced to 53-55% of its original mass, begin extinguishing the fire. Quickly open the prepared fire extinguisher 3 meters in front of the woodpile, quickly approach the woodpile and spray towards the top, bottom, front and two sides of the woodpile.

[0096] (5) Test results

[0097] The experiment was conducted in an open air environment with a breeze, which increased the difficulty of fire extinguishing compared to the national standard requirements, but the fire could still be extinguished within 4 to 6 seconds. The data is as follows:

[0098] Fire extinguisher Specification Fire extinguishing agent Fire extinguishing time(s) Continuous spraying time (s) Whether there is recurrence 1# 3Kg First fire extinguisher 5.48 23.87 none 2# 3Kg First fire extinguisher 4.91 23.45 none

[0099] (6) Comparison with the current national standard ABC dry powder fire extinguishing agent that dominates the market

[0100] In order to reflect the effect of the first fire extinguishing agent of the present invention, while conducting this experiment, a comparative experiment was conducted using national standard ABC dry powder (model specification: ABC-NH4H2PO4 (75%) + (NH4)2SO4 (15%); measured values: NH4H2PO4 content 76.8%, (NH4)2SO4 content 13.9%): three 3Kg dry powder fire extinguishers were filled, numbered 3#, 4#, and 5#, and the other 3Kg dry powder fire extinguishers were filled under the same experimental conditions. The results are as follows:

[0101] Fire extinguisher Specification Fire extinguishing agent Fire extinguishing time(s) Continuous spraying time (s) Whether there is recurrence 3# 3kg National Standard ABC 8.43 21.73 have 4# 3kg National Standard ABC 7.69 22.36 none 5# 3kg National Standard ABC 9.86 21.11 have

[0102] It can be seen from the data that the national standard fire extinguishing agent has a slightly shorter continuous spraying time, indicating that its fluidity is better, because it has undergone surface modification treatment, and thus the spraying intensity is higher, while the first fire extinguishing agent of the present invention has not undergone surface modification treatment, and its fluidity is slightly worse; the national standard ABC dry powder used in the comparative experiment has obvious smoke from beginning to end during the fire extinguishing process. After the flames were extinguished, the woodpile was still smoking, and both 3# and 5# rekindled, indicating that its cooling effect was poor.

[0103] Example 3

[0104] In an open space, choose a windless and sheltered place, open the angle valve of a 10 kg liquefied gas cylinder, and open the valve to the maximum to allow the liquefied gas to spray out. Use an igniter to ignite the gas from the side and rear of the direction in which the gas is sprayed. Quickly open the portable 3 kg dry powder fire extinguisher prepared in Example 2, spray from the side and rear of the direction in which the flame is sprayed, and the flame will be extinguished in 1 to 2 seconds.

[0105] Example 4

[0106] The first fire extinguishing agent prepared in Example 1 is used, methoxy silicone oil is selected as the surfactant, and the added amount is 2.5% of the first fire extinguishing agent (by weight); and the fire extinguishing performance enhancer is selected from hydrated magnesium acetate or carbonamide.

[0107] S1. Add 50 kg of the first fire extinguishing agent prepared in Example 1 into a high-speed mixer, adjust the speed to 240 rpm, mix for 10 minutes, add 5 kg of surfactant in 3 portions, and control the temperature to 60°C;

[0108] S2, adjust the speed to 480 rpm, add 50 kg of the first fire extinguishing agent and continue mixing for 15 minutes, and control the temperature to 60°C;

[0109] S3, adjust the speed to 800-1200 rpm, add 120 kg of the first fire extinguishing agent and continue mixing for 15 minutes, control the temperature at 60°C, add 30 kg of the fire extinguishing performance enhancer, continue mixing for 5 minutes, and stop;

[0110] S4. When the temperature naturally drops below 30°C, the material can be discharged to obtain the second fire extinguishing agent, which is packaged and packaged to make an ABC type dry powder fire extinguishing agent.

[0111] Example 5

[0112] In this embodiment, the smallest model of spray riveting machine produced by a certain factory is selected for testing. The whole machine weight of the spray riveting machine is 350 kg, equipped with a 50-type nozzle, a 5.5Kw feeding motor, a nozzle diameter of 50, a spraying pressure of 0.8Mpa, a horizontal distance of 200 meters for spraying cement mortar, a vertical height of 20 meters, and a spraying volume of 3 cubic meters per hour.

[0113] The type A dry powder fire extinguishing agent prepared in Example 1 was used for spraying test and compared with the cement mortar spraying data. The results are as follows:

[0114] materials Injection pressure Horizontal distance Vertical Height Injection volume Equivalent water gun measurement unit Cement mortar 0.8Mpa 202m 21m <![CDATA[3M 3 / h]]> 0.833L / s Second fire extinguishing agent 0.8Mpa 226m 58m <![CDATA[6.6M 3 / h]]> 1.83L / s

[0115] Through data comparison, it can be seen that by adopting this type of engineering equipment, the vertical height of the spraying of the second fire extinguishing agent of the present invention can be increased by 2.5 times, but some larger particles of powder accumulate in the pipeline; the spraying amount is doubled, and the horizontal distance of the spraying is increased by about 10%. The vertical height, horizontal distance and spraying amount of the spraying reach 226 meters, 58 meters and 1.83 liters / second respectively. From the spraying amount, the dry powder is 1.83 liters / second. The subsequent measures such as enhancing the fluidity of the powder, increasing the pressure and adding a water gun can further increase the spraying distance, height and spraying amount.

[0116] It can be seen that the dry powder fire extinguishing agent of the present invention can be used in conjunction with such equipment to extinguish fires in larger areas.

[0117] The fire extinguishing agent provided by the present invention utilizes the characteristics of crystalline hydrates such as calcium sulfate dihydrate, realizes the combination of liquid water and solid dry powder, and exhibits better characteristics than existing dry powder fire extinguishing products:

[0118] 1. When heated, it releases water molecules, which can absorb heat and play a cooling role, effectively preventing the phenomenon of resurgence;

[0119] 2. The fire extinguishing agent is sprayed onto the surface of the burning object, and the heat quickly decomposes into gaseous water molecules, isolating the burning object from contact with oxygen, and diffuses at a high speed, diluting the combustible gas, combustion-supporting gas and toxic gas at the fire scene, thereby playing a role in suppressing combustion, explosion and poisoning.

[0120] The fire extinguishing material with calcium sulfate dihydrate as the main ingredient and the fire extinguishing agent prepared therefrom have obvious cost advantages and a wide range of applications. The fire extinguishing material can be used to extinguish fires of Class A, B, C, E and F, as well as forest fires and fires of dangerous chemicals, and is particularly suitable for extinguishing Class A fires (such as clothing fabric fires). The recycling value of solid waste can also be expanded.

[0121] The above description is only a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Although the present invention has been presented as a preferred embodiment as above, it is not intended to limit the present invention. Any technician familiar with the profession can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention still falls within the scope of the technical solution of the present invention.

Claims

1. A method for preparing a calcium sulfate dihydrate fire extinguishing material, characterized in that: Processing solid waste containing calcium sulfate dihydrate into powder with a particle diameter of less than 250 μm at 50-70° C. as the first fire extinguishing material, wherein the content of calcium sulfate is ≥80%; The solid waste is one or more of natural gypsum ore, phosphate ore tailings, or phosphogypsum or desulfurized gypsum produced in a coal desulfurization process.

2. The method for preparing the calcium sulfate dihydrate fire extinguishing material according to claim 1, characterized in that: When the water content of the first fire extinguishing material is less than a set threshold, a water content regulator is used to mix with the first fire extinguishing material to make the water content of the mixture greater than or equal to the threshold, and the obtained mixture is the second fire extinguishing material.

3. The method for preparing a fire extinguishing material prepared from calcium sulfate dihydrate according to claim 2, characterized in that: The water content regulator is one or more of magnesium sulfate heptahydrate, calcium chloride hexahydrate or aluminum alum.

4. The method for preparing the calcium sulfate dihydrate fire extinguishing material according to any one of claims 1 or 2, characterized in that: The first fire extinguishing material or the second fire extinguishing material is screened into components including a first particle size, a second particle size, a third particle size, a fourth particle size and a fifth particle size, and each component of the particle size is a third fire extinguishing material, wherein the first particle size is less than 20 μm, the second particle size is 20-40 μm, the third particle size is 40-63 μm, the fourth particle size is 63-125 μm; and the fifth particle size is 125-250 μm.

5. The method for preparing the calcium sulfate dihydrate fire extinguishing material according to claim 4, characterized in that: The third fire extinguishing materials with different particle sizes are mixed to obtain a fourth fire extinguishing material.

6. The method for preparing the calcium sulfate dihydrate fire extinguishing material according to claim 5, characterized in that: Add ingredients with particle diameter less than 20 μm to the fourth fire extinguishing material, mix evenly, and obtain the fifth fire extinguishing material; the ingredients are one or more of fly ash, wood ash or soil from the old Yellow River course.

7. A method for preparing a fire extinguishing agent, characterized in that: include: The fifth fire extinguishing material is subjected to surface activation treatment to obtain a first fire extinguishing agent.

8. The method for preparing a fire extinguishing agent according to claim 7, characterized in that: The surfactant used in the surface active treatment is one or more of methoxy silicone oil, hydrogen silicone oil or fluorocarbon silicone oil. Calculated by weight, the added amount of the surfactant is 0.5-2.5% of the fifth fire extinguishing material.

9. The method for preparing a fire extinguishing agent according to claim 7, characterized in that: A fire extinguishing performance enhancer is added to the first fire extinguishing agent to obtain a second fire extinguishing agent.

10. The method for preparing a fire extinguishing agent according to claim 9, characterized in that: The fire extinguishing performance enhancer is one or both of hydrated magnesium acetate and carbonamide.

11. A fire extinguishing material prepared by the method for preparing calcium sulfate dihydrate fire extinguishing material according to any one of claims 1 to 7.

12. A fire extinguishing agent prepared according to the method for preparing a fire extinguishing agent according to any one of claims 8 to 10.

13. Use of the fire extinguishing material according to claim 11 or the fire extinguishing agent according to claim 12 in fire extinguishing.

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