Mining inhibitor for preventing and treating coal spontaneous combustion in goaf and preparation method thereof

Abstract

This invention belongs to the technical field of fire prevention and extinguishing materials, and discloses a mining inhibitor for preventing spontaneous combustion of coal in goaf areas and its preparation method. The mining inhibitor is composed of a mining inhibitor matrix and water, with the amount of water being 45% to 60% of the total amount of the mining inhibitor matrix. The mining inhibitor matrix, by mass, comprises the following components: 2-3 parts oil-phase synergist, 5-6 parts surfactant, 5-6 parts aqueous-phase dispersant, 3-4 parts fire extinguishing agent, and 1-1.5 parts acid-base neutralizer. The oil-phase synergist is one or both of ammonium carboxylate and sodium bicarbonate; the fire extinguishing agent is one or more of sodium dodecyl sulfate, sodium fatty alcohol polyoxyethylene ether sulfate, and dimethyl methylphosphonate. The preparation method of this invention is simple, efficient, low-cost, and widely applicable; the prepared mining inhibitor is non-toxic, green, and pollution-free, and has excellent inhibitory properties.

Description

Technical Field

[0001] This invention relates to the field of fire prevention and extinguishing materials technology, and in particular to a mine inhibitor for preventing spontaneous combustion of coal in goaf areas and its preparation method. Background Technology

[0002] Spontaneous combustion of coal is one of the most pressing problems to be solved in coal mine safety production. Fires caused by spontaneous combustion of coal pose a serious threat to coal mine safety, damaging underground equipment and, in severe cases, endangering the lives of underground workers. Therefore, taking effective prevention and control measures is of paramount importance to reducing the economic losses caused by spontaneous combustion of coal to the coal industry and improving the safety of coal mine workers.

[0003] Spontaneous combustion of coal is a highly complex physicochemical process involving physical adsorption, chemical adsorption, and chemical reactions. It is also influenced by various factors, including the properties of the coal itself, the degree of coal metamorphism, the oxygen concentration within the goaf, and the intensity of air leakage. Currently, the main methods for preventing spontaneous combustion of coal in goafs include grouting with yellow mud, injecting inert gas, and adding inhibitors. Among these, adding inhibitors is the most widely used method because it is more convenient and effective than the other two.

[0004] Commonly used inhibitors in the prior art include gel inhibitors, foam inhibitors, and alkaline inhibitors. Among them, gel inhibitors, although they have strong fluidity and permeability, generally have a short inhibition lifespan, which is not conducive to large-scale use. Foam inhibitors are easily affected by temperature and pH, and their large surface free energy makes them prone to breakage and failure. Once the foam collapses, the inhibitory performance is lost. Although alkaline inhibitors have the advantages of being inexpensive and efficient, their low solubility and tendency to cause clogging can affect the inhibition effect to some extent, and they are generally highly corrosive.

[0005] Therefore, the present invention provides a mine inhibitor for preventing spontaneous combustion of coal in goaf areas and its preparation method. Summary of the Invention

[0006] To address the shortcomings of existing technologies and achieve efficient inhibition of spontaneous combustion of coal in goaf areas, this invention provides a mining inhibitor for preventing spontaneous combustion of coal in goaf areas and its preparation method. This invention obtains a mining inhibitor by compounding an oil-phase synergist, a surfactant, an aqueous-phase dispersant, an inhibitory fire extinguishing agent, an acid-base neutralizer, and water in a specific ratio. Through the synergistic effect of the components, the problem of poor inhibition effect of a single colloidal agent is effectively solved. Using a mixture of stearic acid and sodium dodecylbenzene sulfonate as the surfactant in the inhibitor effectively solves the shortcomings of poor wetting and penetration of the inhibitor into the coal body. Adjusting the pH value of the final inhibitor to neutral ensures the performance of the surfactant and reduces the impact of the material on transportation pipelines and the mining area.

[0007] The present invention provides a mine-use inhibitor for preventing spontaneous combustion of coal in goaf areas and its preparation method, which is achieved through the following technical solution:

[0008] The first objective of this invention is to provide a mining inhibitor for preventing spontaneous combustion of coal in goaf areas, which is composed of a mining inhibitor matrix and water, wherein the amount of water is 45% to 60% of the total amount of the mining inhibitor.

[0009] The raw materials for preparing the mineral inhibitor matrix, by weight, include the following components:

[0010] 2-3 parts oil-phase synergist, 5-6 parts surfactant, 5-6 parts aqueous-phase dispersant, 3-4 parts fire extinguishing agent, 1-1.5 parts acid-base neutralizer;

[0011] The oil phase synergist is one or both of ammonium carboxylate and sodium bicarbonate;

[0012] The fire extinguishing agent is one or more of sodium dodecyl sulfate, sodium fatty alcohol polyoxyethylene ether sulfate, and dimethyl methylphosphonate.

[0013] Furthermore, the surfactant is one or both of stearic acid and sodium dodecylbenzenesulfonate.

[0014] Furthermore, the surfactant is a mixture of stearic acid and sodium dodecylbenzenesulfonate;

[0015] Furthermore, the mass ratio of stearic acid to sodium dodecylbenzenesulfonate is 1:1 to 1.5.

[0016] Furthermore, the oil phase synergist is a mixture of ammonium carboxylate and sodium bicarbonate;

[0017] The mass ratio of ammonium carboxylate to sodium bicarbonate is 1:1 to 1.5.

[0018] Furthermore, the fire extinguishing agent is a mixture of sodium dodecyl sulfate, sodium fatty alcohol polyoxyethylene ether sulfate, and dimethyl methylphosphonate;

[0019] The mass ratio of sodium dodecyl sulfate, sodium fatty alcohol polyoxyethylene ether sulfate, and dimethyl methylphosphonate is 1–1.5:1–1.5:1–1.5.

[0020] Furthermore, the acid-base neutralizing agent is one or more of sodium bicarbonate, ammonium bicarbonate, and acrylic acid;

[0021] The aqueous dispersant is sodium silicate.

[0022] Furthermore, the acid-base neutralizing agent is a mixture of sodium bicarbonate, ammonium bicarbonate, and acrylic acid;

[0023] The mass ratio of sodium bicarbonate, ammonium bicarbonate and acrylic acid is 1-1.5:1-1.5:1-1.5.

[0024] A second objective of this invention is to provide a method for preparing the above-mentioned mining inhibitor, comprising the following steps:

[0025] Weigh out each of the raw materials for preparing the mining inhibitor according to the above proportions, and set aside for later use;

[0026] The weighed oil phase synergist is mixed with water and stirred for the first time to obtain the inhibitor base material.

[0027] The weighed surfactant, aqueous dispersant and inhibitor base are mixed and stirred a second time. Then the weighed fire extinguishing inhibitor and acid-base neutralizer are added and mixed evenly to obtain a mining inhibitor with a neutral pH.

[0028] Furthermore, the stirring temperature of the first stirring treatment is ≤70℃, the stirring rate is 100~300r / min, and the stirring time is 8~12h.

[0029] Furthermore, the stirring temperature for the second stirring treatment is 55–65°C, the stirring rate is 100–300 r / min, and the stirring time is 8–16 h.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] This invention obtains a mining inhibitor by compounding an oil-phase synergist, a surfactant, an aqueous dispersant, a fire extinguishing agent, and an acid-base neutralizer in a specific ratio. The oil-phase synergist forms a protective film on the coal surface to isolate oxygen; the surfactant increases the wettability and permeability of the inhibitor on the coal; the aqueous dispersant provides some cooling to the coal; the fire extinguishing agent eliminates active groups during the spontaneous combustion process of coal; and the acid-base neutralizer adjusts the pH of the liquid-phase inhibitor to maintain its inhibitory activity.

[0032] The preparation method of this invention is simple, efficient, low in cost, and highly applicable. Furthermore, the prepared mining inhibitor is non-toxic, green, and pollution-free, and has excellent inhibitory properties. It can effectively fill the coal pores in the goaf and achieve the goal of isolating oxygen during a fire. Attached Figure Description

[0033] Figure 1 The CO concentration changes of the mining inhibitors prepared in Example 1 and Comparative Examples 1-5 are shown. Detailed Implementation

[0034] The technical solutions in the embodiments of the present invention will be clearly and completely described below.

[0035] This invention provides a mine-use inhibitor for preventing spontaneous combustion of coal in goaf areas, and its preparation method is as follows:

[0036] Step 1: Weigh the raw materials for preparing the mineral inhibitor matrix and water respectively. The amount of water is 45% to 60% of the total amount of the mineral inhibitor. Set aside for later use.

[0037] The raw materials for preparing the mining inhibitor matrix are weighed according to the following mass ratios: 2-3 parts oil phase synergist, 5-6 parts surfactant, 5-6 parts aqueous phase dispersant, 3-4 parts fire extinguishing agent, and 1-1.5 parts acid-base neutralizer.

[0038] It should be noted that, in order to improve the inhibition performance of the inhibitor, this invention preferably uses one or both of ammonium carboxylate and sodium bicarbonate as the oil phase synergist to enhance the synergist's ability to form a protective film on the coal surface. Furthermore, in a preferred embodiment of this invention, the oil phase synergist is a mixture of ammonium carboxylate and sodium bicarbonate in a mass ratio of 1:1 to 1.5.

[0039] To improve the flame retardant properties of the fire extinguishing agent, this invention preferably uses one or more of sodium dodecyl sulfate, sodium fatty alcohol polyoxyethylene ether sulfate, and dimethyl methylphosphonate as the fire extinguishing agent to achieve efficient flame retardancy of coal in goaf areas. Furthermore, to enhance the synergistic effect among the components of the fire extinguishing agent, in a preferred embodiment of this invention, the fire extinguishing agent used is more preferably a mixture of sodium dodecyl sulfate, sodium fatty alcohol polyoxyethylene ether sulfate, and dimethyl methylphosphonate in a mass ratio of 1–1.5:1–1.5:1–1.5.

[0040] To ensure that the inhibitor can fully wet and penetrate the target coal body, this invention preferably uses one or both of stearic acid and sodium dodecylbenzenesulfonate as surfactants. Furthermore, to ensure that the inhibitory performance is fully realized, in a preferred embodiment of this invention, the surfactant used is a mixture of stearic acid and sodium dodecylbenzenesulfonate in a mass ratio of 1:1 to 1.5.

[0041] This invention takes into account the influence of the pH value of the mixed materials on the performance of the surfactant. Preferably, the acid-base neutralizing agent used is mainly used to adjust the pH of the mining inhibitor to neutral, so as to ensure that the surfactant enhances the wetting and penetration effect of the inhibitor on the target coal body. This invention preferably uses one or more of sodium bicarbonate, ammonium bicarbonate, and acrylic acid as the acid-base neutralizing agent. Furthermore, to ensure the effectiveness of acid-base neutralization, in a preferred embodiment of this invention, the preferred acid-base neutralizing agent is a mixture of sodium bicarbonate, ammonium bicarbonate, and acrylic acid in a mass ratio of 1–1.5:1–1.5:1–1.5.

[0042] Furthermore, considering factors that enhance and improve the cooling effect of the inhibitor on the coal body, the present invention preferably uses sodium silicate as an aqueous dispersant.

[0043] Step 2: Weigh out the oil phase synergist and mix it with water to obtain the inhibitor base material;

[0044] In view of the normal progress of the subsequent mixing of various materials, the present invention first mixes the oil phase synergist with water by stirring to achieve the requirements of a stable environment for material mixing, thereby obtaining the inhibitor base material.

[0045] In order to ensure the effectiveness of the components during stirring, in a preferred embodiment of the present invention, the stirring temperature should be ≤70℃. Furthermore, to ensure thorough mixing of the oil-phase synergist with water, in a preferred embodiment of the present invention, the stirring rate is 100–300 r / min, and the stirring time is 8–12 h.

[0046] Furthermore, this invention uses oil-phase synergists and water as inhibitor base materials, which can provide a stable environment that allows for the maximum performance of material properties during the subsequent mixing of various materials.

[0047] Step 3: Mix the weighed surfactant, aqueous dispersant and the inhibitor base material, and stir. After stirring, add the weighed fire extinguishing inhibitor and acid-base neutralizer and mix well to obtain a mining inhibitor with a neutral pH.

[0048] This invention takes into account the need to thoroughly mix various auxiliary materials before adding the fire extinguishing agent. First, the surfactant, aqueous dispersant, and the prepared fire extinguishing agent base are mixed and stirred at a stirring rate of 100–300 r / min for 8–16 hours to ensure thorough mixing. Then, the fire extinguishing agent and acid-base neutralizer are added and mixed to ensure that the fire extinguishing agent and acid-base neutralizer can fully mix with the previously mixed material that enhances the fire extinguishing performance and achieve complementary properties between the components.

[0049] Example 1

[0050] This embodiment provides a mining inhibitor for preventing spontaneous combustion of coal in goaf areas, which is composed of a mining inhibitor matrix and water. The mining inhibitor matrix, by mass, comprises the following raw materials:

[0051] 2.43 parts oil-phase synergist, 5.29 parts surfactant, 5.29 parts aqueous-phase dispersant, 3.75 parts fire extinguishing agent, 1.25 parts acid-base neutralizer;

[0052] The oil phase synergist is prepared by mixing ammonium carboxylate and sodium bicarbonate in equal mass.

[0053] The surfactant was prepared by mixing stearic acid and sodium dodecylbenzenesulfonate in a mass ratio of 2:3;

[0054] The aqueous dispersant is sodium silicate;

[0055] The fire extinguishing agent is prepared by mixing sodium dodecyl sulfate, sodium fatty alcohol polyoxyethylene ether sulfate and dimethyl methylphosphonate in equal mass.

[0056] The acid-base neutralizing agent is prepared by mixing sodium bicarbonate, ammonium bicarbonate and acrylic acid in equal masses.

[0057] Furthermore, the mineral inhibitor in this embodiment is prepared through the following steps:

[0058] 1) The oil phase synergist prepared above was mixed with 16.99 parts of water and stirred at 220 r / min for 10 h at 50 °C to obtain the inhibitor base material;

[0059] 2) The inhibitor base, surfactant and aqueous dispersant prepared above are mixed and stirred at 220 r / min for 10 h at 60 °C to obtain the mixture;

[0060] 3) Mix the fire extinguishing agent and acid-base neutralizer prepared above, stir at 100 r / min for 1 h at 60 °C, then add the mixture prepared above, and stir at 100 r / min for 5 h to obtain the mine fire extinguishing agent for preventing spontaneous combustion of coal in goaf areas.

[0061] Example 2

[0062] This embodiment provides a mining inhibitor for preventing spontaneous combustion of coal in goaf areas, which is composed of a mining inhibitor matrix and water. The mining inhibitor matrix, by mass, comprises the following raw materials:

[0063] 2 parts oil-phase synergist, 5 parts surfactant, 5 parts aqueous-phase dispersant, 3 parts fire extinguishing agent, 1 part acid-base neutralizer;

[0064] The oil phase synergist is prepared by mixing ammonium carboxylate and sodium bicarbonate in a mass ratio of 1:1.2.

[0065] The surfactant was prepared by mixing stearic acid and sodium dodecylbenzenesulfonate in equal mass ratio;

[0066] The aqueous dispersant is sodium silicate;

[0067] The fire extinguishing agent is prepared by mixing sodium dodecyl sulfate, sodium fatty alcohol polyoxyethylene ether sulfate and dimethyl methylphosphonate in a mass ratio of 1:1.3:1.3.

[0068] The acid-base neutralizing agent is prepared by mixing sodium bicarbonate, ammonium bicarbonate and acrylic acid in a mass ratio of 1:1.3:1.3.

[0069] Furthermore, the mineral inhibitor in this embodiment is prepared through the following steps:

[0070] 1) The oil phase synergist prepared above was mixed with 12.5 parts of water and stirred at 100 r / min for 12 h at 60 °C to obtain the inhibitor base material;

[0071] 2) The inhibitor base material, surfactant and aqueous dispersant prepared above are mixed and stirred at 55°C and 100 r / min for 16 h to obtain the mixture;

[0072] 3) Mix the fire extinguishing agent and acid-base neutralizer prepared above, and stir at 55°C with a stirring rate of 100 r / min for 0.5 h. Then add the mixture prepared above, and stir at a stirring rate of 100 r / min for 4 h to obtain the mine fire extinguishing agent for preventing spontaneous combustion of coal in goaf areas.

[0073] Example 3

[0074] This embodiment provides a mining inhibitor for preventing spontaneous combustion of coal in goaf areas, which is composed of a mining inhibitor matrix and water. The mining inhibitor matrix, by mass, comprises the following raw materials:

[0075] 3 parts oil-phase synergist, 6 parts surfactant, 6 parts aqueous-phase dispersant, 4 parts fire extinguishing agent, 1.5 parts acid-base neutralizer;

[0076] The oil phase synergist is prepared by mixing ammonium carboxylate and sodium bicarbonate in equal mass.

[0077] The surfactant was prepared by mixing stearic acid and sodium dodecylbenzenesulfonate in equal mass ratio;

[0078] The aqueous dispersant is sodium silicate;

[0079] The fire extinguishing agent is prepared by mixing sodium dodecyl sulfate, sodium fatty alcohol polyoxyethylene ether sulfate and dimethyl methylphosphonate in a mass ratio of 1:1.5:1.5.

[0080] The acid-base neutralizing agent is prepared by mixing sodium bicarbonate, ammonium bicarbonate and acrylic acid in a mass ratio of 1:1.5:1.5.

[0081] Furthermore, the mineral inhibitor in this embodiment is prepared through the following steps:

[0082] 1) The oil phase synergist prepared above was mixed with 30.75 parts of water and stirred at 70°C and 300 r / min for 8 h to obtain the inhibitor base material;

[0083] 2) The inhibitor base, surfactant and aqueous dispersant prepared above are mixed and stirred at 300 r / min for 8 h at 65 °C to obtain the mixture;

[0084] 3) Mix the fire extinguishing agent and acid-base neutralizer prepared above, and stir at 100 r / min for 1.5 h at 65 °C. Then add the mixture prepared above, and stir at 100 r / min for 6 h to obtain the mine fire extinguishing agent for preventing spontaneous combustion of coal in goaf areas.

[0085] Comparative Example 1

[0086] This comparative example provides a mining inhibitor for preventing spontaneous combustion of coal in goaf areas, which is composed of a mining inhibitor matrix and water. The mining inhibitor matrix, by mass, comprises the following raw materials:

[0087] 2.43 parts oil-phase synergist, 5.29 parts surfactant, 5.29 parts aqueous-phase dispersant, 3.75 parts fire extinguishing agent, 1.25 parts acid-base neutralizer;

[0088] The oil phase synergist is prepared by mixing ammonium carboxylate and sodium bicarbonate in equal mass.

[0089] The surfactant was prepared by mixing stearic acid and sodium dodecylbenzenesulfonate in a mass ratio of 2:3;

[0090] The aqueous dispersant is sodium silicate;

[0091] The fire extinguishing agent is prepared by mixing sodium dodecyl sulfate, sodium fatty alcohol polyoxyethylene ether sulfate and dimethyl methylphosphonate in equal mass.

[0092] The acid-base neutralizing agent is prepared by mixing sodium bicarbonate, ammonium bicarbonate and acrylic acid in equal masses.

[0093] Furthermore, the mineral inhibitor of this comparative example is prepared through the following steps:

[0094] The oil-phase synergist, 5.29 parts surfactant, 5.29 parts aqueous dispersant, 3.75 parts fire extinguishing agent, and 1.25 parts acid-base neutralizer prepared above were directly mixed with 16.99 parts water, and then stirred at a stirring rate of 100 r / min for 5 h to obtain a mine fire extinguishing agent for preventing spontaneous combustion of coal in goaf areas.

[0095] In other words, the only difference between this comparative example and Example 1 is that:

[0096] In this comparative example, the oil phase synergist, surfactant, aqueous phase dispersant, fire extinguishing inhibitor, acid-base neutralizer and water are directly mixed without stepwise addition when preparing the mining inhibitor.

[0097] Comparative Example 2

[0098] This comparative example provides a mining inhibitor for preventing spontaneous combustion of coal in goaf areas, which is composed of a mining inhibitor matrix and water. The mining inhibitor matrix, by mass, comprises the following raw materials:

[0099] 2.43 parts oil-phase synergist, 5.29 parts surfactant, 5.29 parts aqueous-phase dispersant, and 3.75 parts fire extinguishing agent;

[0100] The oil phase synergist is prepared by mixing ammonium carboxylate and sodium bicarbonate in equal mass.

[0101] The surfactant was prepared by mixing stearic acid and sodium dodecylbenzenesulfonate in a mass ratio of 2:3;

[0102] The aqueous dispersant is sodium silicate;

[0103] The fire extinguishing agent is prepared by mixing sodium dodecyl sulfate, sodium fatty alcohol polyoxyethylene ether sulfate and dimethyl methylphosphonate in equal mass.

[0104] The acid-base neutralizing agent is prepared by mixing sodium bicarbonate, ammonium bicarbonate and acrylic acid in equal masses.

[0105] Furthermore, the mineral inhibitor of this comparative example is prepared through the following steps:

[0106] 1) The oil phase synergist prepared above was mixed with 16.99 parts of water and stirred at 220 r / min for 10 h at 50 °C to obtain the inhibitor base material;

[0107] 2) The inhibitor base, surfactant and aqueous dispersant prepared above are mixed and stirred at 220 r / min for 10 h at 60 °C to obtain the mixture;

[0108] 3) Mix the fire extinguishing agent prepared above and stir at 100 r / min for 1 h at 60 °C. Then add the mixture prepared above and stir at 100 r / min for 5 h to obtain the mine fire extinguishing agent for preventing spontaneous combustion of coal in goaf areas.

[0109] In other words, the only difference between this comparative example and Example 1 is that:

[0110] No acid-base neutralizing agent was added to this comparative example.

[0111] Comparative Example 3

[0112] This comparative example provides a mining inhibitor for preventing spontaneous combustion of coal in goaf areas, which is composed of a mining inhibitor matrix and water. The mining inhibitor matrix, by mass, comprises the following raw materials:

[0113] 2.43 parts oil-phase synergist, 5.29 parts surfactant, and 3.75 parts fire extinguishing agent;

[0114] The oil phase synergist is prepared by mixing ammonium carboxylate and sodium bicarbonate in equal mass.

[0115] The surfactant was prepared by mixing stearic acid and sodium dodecylbenzenesulfonate in a mass ratio of 2:3;

[0116] The aqueous dispersant is sodium silicate;

[0117] The fire extinguishing agent is prepared by mixing sodium dodecyl sulfate, sodium fatty alcohol polyoxyethylene ether sulfate and dimethyl methylphosphonate in equal mass.

[0118] The acid-base neutralizing agent is prepared by mixing sodium bicarbonate, ammonium bicarbonate and acrylic acid in equal masses.

[0119] Furthermore, the mineral inhibitor of this comparative example is prepared through the following steps:

[0120] 1) The oil phase synergist prepared above was mixed with 16.99 parts of water and stirred at 220 r / min for 10 h at 50 °C to obtain the inhibitor base material;

[0121] 2) The inhibitor base and surfactant prepared above are then mixed and stirred at 60°C and a stirring rate of 220 r / min for 10 h to obtain the mixture;

[0122] 3) Mix the fire extinguishing agent prepared above and stir at 100 r / min for 1 h at 60 °C. Then add the mixture prepared above and stir at 100 r / min for 5 h to obtain the mine fire extinguishing agent for preventing spontaneous combustion of coal in goaf areas.

[0123] In other words, the only difference between this comparative example and Example 1 is that:

[0124] This comparative example does not contain acid-base neutralizers or aqueous dispersants.

[0125] Comparative Example 4

[0126] This comparative example provides a mining inhibitor for preventing spontaneous combustion of coal in goaf areas, which is composed of a mining inhibitor matrix and water. The mining inhibitor matrix, by mass, comprises the following raw materials:

[0127] 2.43 parts oil-phase synergist, 5.29 parts surfactant, 5.29 parts aqueous-phase dispersant, 3.75 parts fire extinguishing agent, 1.25 parts acid-base neutralizer;

[0128] The surfactant is prepared by mixing stearic acid and sodium dodecylbenzenesulfonate in a mass ratio of 2:3.

[0129] The fire extinguishing agent is prepared by mixing sodium dodecyl sulfate, sodium fatty alcohol polyoxyethylene ether sulfate and dimethyl methylphosphonate in equal mass.

[0130] Furthermore, the mineral inhibitor of this comparative example is prepared through the following steps:

[0131] 1) The oil phase synergist prepared above was mixed with 16.99 parts of water and stirred at 220 r / min for 10 h at 50 °C to obtain the inhibitor base material;

[0132] 2) The inhibitor base, surfactant and aqueous dispersant prepared above are mixed and stirred at 220 r / min for 10 h at 60 °C to obtain the mixture;

[0133] 3) Mix the fire extinguishing agent and acid-base neutralizer prepared above, stir at 100 r / min for 1 h at 60 °C, then add the mixture prepared above, and stir at 100 r / min for 5 h to obtain the mine fire extinguishing agent for preventing spontaneous combustion of coal in goaf areas.

[0134] In other words, the only difference between this comparative example and Example 1 is that:

[0135] This comparative example does not contain oil phase synergists, acid-base neutralizers, or aqueous phase dispersants.

[0136] Comparative Example 5

[0137] This comparative example provides a mining inhibitor for preventing spontaneous combustion of coal in goaf areas, which is composed of a mining inhibitor matrix and water. The mining inhibitor matrix, by mass, comprises the following raw materials:

[0138] 3.75 parts of fire extinguishing agent;

[0139] The fire extinguishing agent is prepared by mixing sodium dodecyl sulfate, sodium fatty alcohol polyoxyethylene ether sulfate, and dimethyl methylphosphonate in equal mass.

[0140] Furthermore, the mineral inhibitor of this comparative example is prepared through the following steps:

[0141] 1) Mix 3.75 parts of the fire extinguishing agent prepared above with 16.99 parts of water, stir at 100 r / min for 1 h at 60 °C, then add the mixture prepared above, and stir at 100 r / min for 5 h to obtain the mine fire extinguishing agent for preventing spontaneous combustion of coal in goaf areas.

[0142] In other words, the only difference between this comparative example and Example 1 is that:

[0143] This comparative example does not contain surfactants, oil-phase synergists, acid-base neutralizers, or aqueous-phase dispersants.

[0144] Experimental Section

[0145] (1) Preparation of experimental coal samples:

[0146] A certain amount of coal sample is crushed to a particle size of less than 10 mm. The crushed coal sample is then sieved into five particle sizes: 0-0.9 mm, 0.9-3 mm, 3-5 mm, 5-7 mm, and 7-10 mm using sieves with mesh sizes of 0.9 mm, 3 mm, 5 mm, 7 mm, and 10 mm. The five different particle sizes are then mixed evenly by weight to obtain 1 kg of experimental coal sample.

[0147] (2) Preparation of experimental samples:

[0148] In this invention, 10g of the mining inhibitor prepared in Example 1 and Comparative Examples 1-5 were taken respectively, and mixed with 1kg of the experimental coal sample prepared above. The mixture was then sealed, stored and dried for 2 hours to serve as the experimental group. Another 1kg of the experimental coal sample prepared above (without any inhibitor added) was sealed, stored and dried for 2 hours to serve as the blank control group.

[0149] There are six experimental groups in total. The experimental groups corresponding to the mineral inhibitors prepared in Example 1 and Comparative Examples 1-5 are named Experiment 1, Experiment 2, Experiment 3, Experiment 4, Experiment 5 and Experiment 6, respectively.

[0150] This invention conducts programmed temperature rise experiments on samples from the above-mentioned experimental groups 1-6 to analyze the CO generation rate of coal samples and the inhibitory effect of fire extinguishing agents on raw coal samples.

[0151] Programmed heating experiment: The test sample was loaded into the experimental coal sample container, with a PT100 platinum resistance thermometer reserved in the center of the coal body. The coal sample container was sealed and the gas circuit was connected. The fully automatic air pump was turned on, the flow rate was set, and the airtightness of the entire device was checked. Then, the air was pre-blown for 20 minutes. The programmed heating furnace was turned on, and the heating temperature was set for heating. When the medium temperature rose to the predetermined temperature, the gas was collected and chromatographic analysis was performed. After the experiment, the CO generation rate of the coal sample was analyzed and processed.

[0152] The experimental samples were heated using a programmed temperature ramp experiment, and the CO release at different temperatures was analyzed using gas chromatography. Concentration change curves were plotted, and the inhibition rate of coal oxidation by adding different inhibitors was calculated based on the CO release at 100℃. The test results are as follows: Figure 1 As shown in Table 1.

[0153] The CO generation rate and its inhibition rate were measured using a comprehensive coal spontaneous combustion characteristic testing device. Relevant data are as follows: Figure 1 As shown in Table 1.

[0154] This invention, following the methods described in "General Technical Conditions for Fire Inhibitors for Coal Mines MT / T 700-2019", tested the inhibition rate of the mining inhibitors prepared in experimental groups 1-6 and the CO generation rate of the coal samples, and the test results are as follows. Figure 1 As shown in Table 1. Among them, the CO generation rate and inhibition rate were measured using a comprehensive coal spontaneous combustion characteristic measuring device, with the coal samples subjected to inhibition treatment.

[0155] The formula for calculating resistivity I is:

[0156]

[0157] in,

[0158] And in the above formulas:

[0159] I represents the resistivity, expressed as a percentage.

[0160] v x The volume of CO generated by the inhibited coal sample is expressed in m³. 3 ;

[0161] v y The volume of CO produced by the raw coal sample, in m³. 3 ;

[0162] C n The volume of the nth test point in the inhibited coal sample is expressed in cubic meters (m³). 3 When n=1, C=0;

[0163] C' n The volume of the nth test point in the raw coal sample is expressed in cubic meters (m³). 3 When n=1, C'0=0;

[0164] i represents the maximum number of measurements;

[0165] The parallel error of the same sample is within ±3%.

[0166] Table 1. Resistance test results

[0167] Resistance rate / % 94 90 85 59 49 24

[0168] From Table 1 and Figure 1 It can be seen that, under the premise that the components of the mining inhibitor, except for the variable component, remain unchanged, programmed temperature rise experiments were conducted on groups 1-6 respectively. Analysis of the CO generation rate of the coal samples after inhibition and the inhibition rate of the inhibitor on the coal samples in the examples and comparative examples revealed that the synergistic effect among the components of the high-efficiency inhibitor is effective in inhibiting the raw coal samples. Furthermore, the inhibitor in group 1 showed the best inhibition effect. Therefore, it is concluded that the mining inhibitor for preventing spontaneous combustion of coal in goaf areas in this invention mainly relies on the synergistic effect of the inhibitor and other materials, achieving the functions of isolating oxygen in the target coal body, cooling it, and eliminating active groups during the spontaneous combustion process. In addition, the preparation method of this inhibitor material is simple and efficient.

[0169] Obviously, the above embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

Claims

1. A mine inhibitor for preventing spontaneous combustion of coal in a gob, characterized by comprising: It is composed of a mining inhibitor matrix and water, with the amount of water being 45% to 60% of the total amount of the mining inhibitor; The raw materials for preparing the mineral inhibitor matrix, by weight, include the following components: 2 to 3 parts oil phase synergist, 5 to 6 parts surfactant, 5 to 6 parts aqueous phase dispersant, 3 to 4 parts fire extinguishing agent, 1 to 1.5 parts acid-base neutralizer; The oil phase synergist is a mixture of ammonium carboxylate and sodium bicarbonate, and the mass ratio of ammonium carboxylate to sodium bicarbonate is 1:1 to 1.

5. The surfactant is a mixture of stearic acid and sodium dodecylbenzene sulfonate, and the mass ratio of stearic acid to sodium dodecylbenzene sulfonate is 1:1 to 1.

5. The fire extinguishing agent is a mixture of sodium dodecyl sulfate, sodium fatty alcohol polyoxyethylene ether sulfate, and dimethyl methylphosphonate, wherein the mass ratio of sodium dodecyl sulfate, sodium fatty alcohol polyoxyethylene ether sulfate, and dimethyl methylphosphonate is 1-1.5:1-1.5:1-1.

5. The acid-base neutralizing agent is a mixture of sodium bicarbonate, ammonium bicarbonate and acrylic acid, and the mass ratio of sodium bicarbonate, ammonium bicarbonate and acrylic acid is 1-1.5:1-1.5:1-1.5; The aqueous dispersant is sodium silicate.

2. A method for preparing the mine inhibitor for preventing and treating coal spontaneous combustion in goaf according to claim 1, characterized in that, Includes the following steps: Weigh out each of the raw materials for preparing the mining inhibitor according to the above proportions, and set aside for later use; The weighed oil phase synergist is mixed with water and stirred for the first time to obtain the inhibitor base material. The weighed surfactant, aqueous dispersant and inhibitor base are mixed and stirred a second time. Then the weighed fire extinguishing inhibitor and acid-base neutralizer are added and mixed evenly to obtain a mining inhibitor with a neutral pH.

3. The method of claim 2, wherein the mine suppressant for preventing spontaneous combustion of coal in goaf is prepared by adding the above-mentioned compound to the above-mentioned base material. The stirring temperature for the first stirring treatment is ≤70℃, the stirring rate is 100r / min~300r / min, and the stirring time is 8h~12h.

4. The method for preparing the mine-use inhibitor for preventing spontaneous combustion of coal in goaf areas as described in claim 2, characterized in that, The second stirring process is carried out at a stirring temperature of 55℃~65℃, a stirring rate of 100r / min~300r / min, and a stirring time of 8h~16h.

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