407 results about "Coal spontaneous combustion" patented technology

It is an adiabatic test method and its apparatus for stimulating the coal autoignition process, which is to locate an adiabatic coal sample jar served as coal low temperature oxidation reaction and to let the gas in the jar firstly go through the copper gas guide pipe in the gas bath temperature control box for preheating and the environment temperature in the box of the reaction always traces the temperature changes in the coal sample jar. It adopts preheat gas path apparatus, gas bath temperature control box, adiabatic coal jar in the temperature control box, temperature control system, which makes the heat generated during the reaction remain in the coal sample to stimulate the coal autoignition process.

The invention discloses a multi-component real-time online remote monitoring device and a method for coal spontaneous combustion indicator gas. For the limit of long distance optical fiber sensing band, the near-infrared band with weaker gas absorption line strength is used for real-time online monitoring the typical alkane gas as CO, CO2, C2H2 and C2H4 in the indicator gas. The multi-component weak signal is detected through the multi-frequency wavelength modulation and novel long optical distance multiple reflection pool technology; the device comprises a laser, a laser controller, a signal generator, a novel multiple reflection pool, an optical fiber collimator, a light beam coupler, a photoelectric detector, a lock-in amplifier, a processing system collecting the signal of A / D and terminal and an anti-explosion case. The device adopts the optical fiber for connection without manpower sampling, the responding sensitivity is high, the device and the method can monitor a variety of indicator gases at the same time with simple operation, good stability and small power, the device is easy to carry and install for field experimentation and the dynamic measuring range is large.

The invention discloses a foam retardant for preventing mine well from spontaneously combusting and a using method thereof. The retardant is characterized in that according to the gross mass of a chemical retardant, 0.5 to 2 percent of oxidizing agent is dissolved in water, and then 1 to 1.5 percent of foaming agent, 0.2 to 0.4 percent of foam stabilizing agent, 0.05 to 0.1 percent of thickening agent and 0.05 to 0.1 percent of emulsifying agent are sequentially added and stirred uniformly so as to prepare the chemical retardant; according to the gross mass of a physical retardant, 10 to 15 percent of inorganic salt and other compositions are added by the same method as the former so as to prepare the physical retardant; when the retardant is used, the chemical retardant is diluted into an aqueous solution with a concentration of between 1.76 and 4.1 weight percent first, and the aqueous solution is sprayed to a target coal layer area; after 30 minutes to 1 hour, the physical retardant which is diluted into an aqueous solution with a concentration of between 11.06 and 16.9 weight percent is sprayed into the same area; and inhibition foams are covered on the surface of the coal layer so as to achieve the effect of preventing the spontaneous combustion for a long time on the coal layer of the area.

The invention discloses a positive pressure bundle pipe monitoring system for mine underground fire and toxic and harmful gas, belonging to the technical field of mine safety monitoring. The positive pressure bundle pipe monitoring system comprises a gas positive-pressure transportation system, a gas analysis system, a control system, a data acquisition system and a workstation. The system transports gas in a monitored area in a centralized positive pressure transportation manner to certain underground or ground sites to perform centralized detection on the components and the concentrations of the gas. Because the gas is transported in the positive pressure manner, the components and the concentrations of the gas in the gas transportation process are not distorted at all, the pipe is not easy to block, the transportation distance is long, no external water enters, whether the pipeline is damaged to leak gas is easy to detect, the gas can automatically enter the analysis detection device, and the detection result is accurate and reliable. The positive pressure bundle pipe monitoring system is applicable to the analysis and monitoring of coal spontaneous combustion in coal mines, exogenous mine fire and toxic and harmful gas in coal mines, and is also applicable to the analysis and monitoring of metal mine fire and toxic and harmful gas.

The invention relates to a composite stopping agent preventing coal spontaneous combustion based on a low-temperature oxidation mechanism of coal, which belongs to the stopping agent preventing coal spontaneous combustion. The composite stopping agent is characterized by comprising the components of catechinic acid, nontoxic phosphite ester, polyethylene glycol 200, lauryl sodium sulfate and solvent-water. The concentration of raw materials in the solvent-water by mass percent is 0.5-1% of catechinic acid, 0.5-1% of nontoxic phosphite ester, 4-7% of polyethylene glycol 200 and 0.5-1% of lauryl sodium sulfate. The stopping agent can not only be in substitution reaction with methyl and methylene in coal to generate stable ether matters, but also be interacted with free radicals of alkyl peroxides generated by oxidization of methyl and methylene in the coal. The free radicals of peroxides are destroyed, so that generation and activity of active groups such as methyl, methylene and the like in coal spontaneous combustion can be inhibited, therefore, the spontaneous combustion character of coal is fundamentally changed and spontaneous combustion of coal is inhibited. Meanwhile, the stopping agent has the physical moisturizing function and can lock water injected in the coal better, so as to prevent coal spontaneous combustion better in the physical inhibition respect.

A compounded latex retardant for preventing coal spontaneous combustion belongs to the technical field of retardants, and comprises the following components by weight ratio: 20 to 80 polymer emulsion, 10 to 90 organic modified clay, and 0.5 to 60 retardant, as well as 1 to 50 dispersant in a concentration of 0.1 to 10wt%. The preparation method comprises the following steps: adding the clay into silane coupling agent solution; performing ultrasonic or stirring dispersion by 30mins; dissolving the dispersant into water of a certain weight ratio, and stirring under 20 to 90 DEG C to get a dispersant solution in a concentration of 0.1 to 10wt%; and adding the organic modified clay and the prepared dispersant solution into the polymer emulsion, fully stirring, adding the retardant, and stirring to achieve uniform concentration. The retardant provided by the invention can not corrode metal equipment during use, harmful gas the wastes can not be generated, no pollution is caused to coal mine environment, and adverse effects and side effects to human body are prevented. Therefore, the retardant is environmental-friendly.

The invention discloses a coal mine goaf coal spontaneous combustion flow field simulation experiment table for simulating temperature field development, air current flowing and gas migration state of residual coal in a coal mine goaf in spontaneous combustion environment. The experiment table comprises a ventilation system, a ventilation working face stope, a simulated goaf, a gas release system, a temperature monitoring system and a data collection system. The experiment table can simulate flow field development of the goaf in a normal ventilation state and in a state when a fire area of the goaf is closed to acquire parameters like gas concentration and speed, spatial pressure and coal rock temperature at different positions of the goaf in a spontaneous combustion environment condition, and a basis can be provided for studying and mastering laws of temperature field development, air current flowing and gas migration in goaf coal spontaneous combustion environment. The experiment table is suitable for simulating temperature field development, air current flowing and gas migration in the coal spontaneous combustion environment of a three-dimensional goaf and judging disastrous and dangerous areas.

The invention discloses a joint treatment method for gas and coal spontaneous combustion in night distance seam mining. Gas gushing out of a stope working face is treated through a 'two intakes and one return' working face ventilation system, long drill holes in the trend of a fissure zone are utilized to replace a high pumping lane to extract gas gushing out of residual coal of night distance seams and a coal seam, thus corner gas overflow on the stope working face is avoided, and the gas extraction project cost is reduced. Gas injecting pipelines are arranged on a belt gate roadway of the stope working face to continuously inject liquid carbon dioxide into a goaf to restrain spontaneous combustion of the residual coal of the coal seam, low-position drill holes are formed in a track gateroadway of the stope working face to inject nitrogen to prevent spontaneous combustion of the coal of the night distance seams after extraction collapse, thus a coal spontaneous combustion three-dimensional preventing and control system of the goaf is formed, float coal spontaneous combustion in the goaf is accurately prevented and treated, finally, the purpose of joint treatment for gas and coalspontaneous combustion in night distance seam mining is achieved, the coal recovery rate of coal and the working face stoping continuous speed are increased, and safe production of the tope working face is guaranteed.

The invention discloses an intelligent gel material for controlling coal spontaneous combustion. The intelligent gel material comprises a super-absorbent temperature-sensitive colloid, an expandable aggregate and a foaming agent, wherein the super-absorbent temperature-sensitive colloid is prepared from one or more of chitosan, starch, acrylic acid and acrylamide through polymerization under the action of an initiating agent and a crosslinking agent under the conditions of an alkaline environment and a high temperature; the expandable aggregate is expandable graphite; the foaming agent is one or more of sodium bicarbonate, ammonium bicarbonate or sodium carbonate. The intelligent gel material disclosed by the invention is extremely high in sensitiveness to the temperature; the physical performance and the chemical structure can be changed over the temperature; compared with a conventional gel, the intelligent gel material is capable of accurately locating a high-temperature fire source and rapidly releasing water in a human body, and plays roles of cooling and extinguishing fire; the viscosity is increased after the water is lost, and the intelligent gel material can be adhered on the surface of the high-temperature fire source to play a role of isolating oxygen; after completing losing water, the intelligent gel material is capable of realizing secondary expansion under the condition of the high temperature, and plays a role of blocking air.

The invention provides a coal spontaneous combustion monitoring and early warning system for coal mine goaf. The coal spontaneous combustion monitoring and early warning system comprises a distributed temperature sensing optical cable, a multi-parameter monitoring device, an underground looped network switch, a monitoring center switch, a monitoring host and a gas pipe. The multi-parameter monitoring device is provided with an optical cable interface, a sampled gas inlet, a sampled gas outlet, a communication end and a wireless communication end. The distributed temperature sensing optical cable is in signal and electric connection with the optical cable interface of the multi-parameter monitoring device, the gas pipe is connected with the sampled gas inlet and the sampled gas outlet of the multi-parameter monitoring device, the communication end of the multi-parameter monitoring device is in bidirectional signal and electric connection with the underground looped network switch, the monitoring center switch and the monitoring host, and when in use, the wireless communication end of the multi-parameter monitoring device is in wireless communication with a wireless remote control device. By means of the coal spontaneous combustion monitoring and early warning system, wide-range temperature monitoring and remote gas monitoring of beam tubes in the goaf is achieved. In addition, the coal spontaneous combustion monitoring and early warning system for the coal mine goaf is low in deployment cost and good in monitoring and early warning timely performance, stability and reliability.

The invention discloses a simple and convenient goaf bundle pipe gas extraction device and method. The device mainly comprises a gas extraction pipeline, a phi 219 main pipe, seven one-sixth ball valves, a flow meter, a connecting pipe, a water drainage pipe, a sampling connecting pipe, a rubber pipe, a pump, connecting pipes of the main pipe and bundle pipes, the four bundle pipes, an embedded main pipe and a hose. The method includes the steps that gas is extracted from the interior of a goaf through negative pressure in the gas extraction pipeline, gas in the goaf is driven by negative pressure in the gas extraction pipeline to flow into the phi 219 main pipe through the bundle pipes, the pump is connected with the phi 219 main pipe through the rubber pipe to pump a proper amount of gas, sampled gas is collected in a sealed mode through sampling bags and analyzed through a gas chromatograph finally, the concentration change rule of various types of gas in the goaf is acquired, and on the basis, the positions and the ranges of three residual coal spontaneous combustion zones in the goaf are judged. The device and method have the advantages of being safe, efficient, simple, convenient to use and capable of saving energy.

The invention discloses an ecological restoration management method for coal spontaneous combustion fire potential areas and standards and aims to provide an ecological restoration mode and technology for loess hilly-gully regions fragile in ecological environment and high in potential fire risk to meet the requirement of large-area ecological restoration projects. Methods and techniques are provided for ecological restoration of control regions by a series of ecological restoration methods including reclaiming land while mining by combination of topsoil resource exploitation, internal drainage and external drainage, performing erosion and torrent control works, adopting engineering technologies and biological methods for reclamation, planting trees for greening and the like.

The invention discloses a coal spontaneous combustion preventing inhibition foam material and a preparation method thereof. The coal spontaneous combustion preventing inhibition foam material belongs to the technical field of coal mine underground coal spontaneous combustion treatment. The coal spontaneous combustion preventing inhibition foam material is characterized by comprising, by weight percentage, 0.5-10% of foaming agent, 0.2-3% of foaming auxiliaries, 0.02-0.5% of thickener, 0.5-5% of inhibitor, 2.5-15% of enhancer and 66.5-96.28% of water. After being foamed, the coal spontaneous combustion preventing inhibition foam material can take foam as the carrier to effectively convey the target inhibitor and enhancer to areas complicated to handle, and generated inhibiting foam achieves multiple oxygen insulating inhibition effects on coal spontaneous combustion and further achieves the aim of preventing coal spontaneous combustion.

A three-phase foam preparing system for preventing coal spontaneous combustion consists of agitator, foam generator, filter connected with agitator and foam generator, air inlet in wall of foam generator, nitrogen injection device, air compressor, bypass pipe on slurry injection pipe. The prepared slurry is filtered then pressed into air or nitrogen, foaming to form air-liquid-solid three-phase foam. Said invention has high foaming efficiency.

The invention provides a method for controlling goaf air leakage in the exploitation process of a shallow buried close-range coal seam. The method mainly comprises technologies such as plugging of earth surface air leaking fractures and detecting and plugging of downhole air leaking channel, namely, first, the widths of earth surface mining-induced fractures are measured and the speed of fracture air leaking is calculated; the fractures with the widths and the air leaking air speeds being out of gauge are plugged, an air inlet roadway and an air outlet roadway which are difficult to cave by a roof in a goaf is caved by a manual way, and air leaking toward the goaf is reduced; next, a beam tube monitoring system is used for monitoring the concentration of O2 in the goaf, and whether air leaking exists or not in the goaf is judged according to the concentration of O2; then, a tracer gas method is used for detecting air leaking channels of downhole coal pillars, the air inlet roadway, the air outlet roadway and the like, and corresponding plugging measures are adopted; and at the time of plugging, a fan-air-window combined pressure regulating method is used for balancing air pressure of the goaf and a working face, goaf air leaking is reduced, and coal spontaneous combustion in the goaf is avoided.

The invention discloses a test method of influence of space and multi-component gas on coal spontaneous combustion tendency. The method includes the steps: adjusting the height of an inner cavity of a reactor, introducing a plurality of gases with different specified components, fluxes and concentrations, acquiring inner cavity temperatures and cavity wall temperatures of various positions in the reactor, recording the concentrations of various gas components in the reactor by a gas concentration analysis system, recording the total time of coal stacker sample spontaneous combustion ignition, analyzing the temperature rising gradient dT / dt after the temperature is 70 DEG C, and finding out the relationship between the gas component concentration and the coal sample spontaneous combustion tendency through comparison of data recorded by the data acquisition system and the gas concentration analysis system and the like. The test method can more truly simulate the coal mine goaf height, and studies the influence of spatial characteristics on the coal spontaneous combustion ignition tendency, the influence of the multi-component environment gas on the coal spontaneous combustion tendency, and the influence of goaf ventilation conditions on the coal spontaneous combustion tendency; and the accuracy of the test result is higher.

A fly ash solidification foamed material for preventing coal spontaneous combustion and a preparation method thereof. The fly ash solidification foamed material comprises the following ingredients, by weight: 40-60 parts of water, 100 parts of fly ash, 25 parts of complex powder for chemically self-producing gas, 1-5 parts of an accelerator, 1-4 parts of an activator, 0.6-1.5 parts of a water reducer, and 0.5-1 parts of a foam stabilizer. The preparing method comprises: adding the foam stabilizer in water and stirring to form a uniform foam solution; adding the fly ash, the complex powder for chemically self-producing gas, the accelerator, the activator, and the water reducer in a dry-blending mixer to form a blended powder; and finally adding the blended powder into the uniform foam solution to obtain the fly ash solidification foamed material. The material of the invention is light in weight, safe and low in costs, and has strong crack penetration capability, adjustable solidification time, great compressive strength, low heat conductivity coefficient, and a good heat insulation effect; foam fluid can uniformly cover loose coal-rock mass; carbon dioxide is released during a foaming reaction process to well dilute the oxygen concentration in residual coal space; and the operation technique is simple.

The invention relates to the field of coal mine safety, in particular to a warning grading method and a warning method for spontaneous combustion of coal. The coal is prone to spontaneous combustion,and the warning for spontaneous combustion of coal is divided into six grades, namely, grey warning, blue warning, yellow warning, orange warning, red warning and black warning. The warning method includes the following steps: collecting O2, CO, CO2, CH4, C2H4 and C2H6 concentration data; judging the warning grade, and setting a warning threshold as R0, wherein the warning threshold of coal spontaneous combustion can be expressed by the following mathematical formula: R0={[O2]>18% union [CO]>50ppm} intersecting {[O2] belongs to (15%, 18%) union [CO]>100ppm} intersecting {[O2] belongs to (12%,15%) union [CO]>150ppm} intersecting {[O2]<12% union [CO]>200ppm}; and issuing a warning and taking measures according to different thresholds. The spontaneous combustion process of coal can be indicated more accurately and sensitively, and higher preventability is achieved.

The invention relates to a novel environment-friendly composite stopping agent capable of preventing coal spontaneous combustion and a preparing method of the novel environment-friendly composite stopping agent. The composite stopping agent comprises a macromolecular matrix, an inorganic stopping agent, a surface active agent and a reinforcing agent. The constituents of the composite stopping agent in an aqueous solution comprise, by mass, the macromolecular matrix occupying 3% to 8% and containing one or two types of polyvinyl alcohol and starch, the inorganic stopping agent occupying 0.5% to 2% and containing one or more of organic modification hydrotalcite, ammonium dihydrogen phosphate and magnesium hydrate, the surface active agent occupying 1% to 3%, the reinforcing agent occupying 0.5% to 4% and the balance water occupying 83% to 95%, wherein the surface active agent is dodecylbenzene sodium sulfonate and the reinforcing agent is calcium hydroxide. The composite stopping agent is sprayed on the surface of coal under normal temperature, other devices and conditions are not needed, harmful gas and waste are not generated, and the composite stopping agent has not toxic and side effect on the human body and is environmentally friendly. Meanwhile, the composite stopping agent is good in physical moisturizing function and can effectively permeate through a coal seam, obtain large contact superficial area with the coal seam and well achieve the coal spontaneous combustion prevention function.

The invention relates to a coal spontaneous-combustion characteristic determining device based on a thermogravimetry.The problem of synchronous measurement of an oxidation temperature rise characteristic curve, mass change quantity and gas production / consumption characteristics of a coal sample under temperature raising programming is effectively solved.High-pressure steel cylinders are connected with a preheating copper pipe through a gas premixing device, the preheating copper pipe is arranged in a coal sample tank support, the coal sample tank support extends out of a box body to be arranged on a balance, a cooling copper pipe is arranged in the top, a coal sample tank is arranged in the coal sample tank support, the preheating copper pipe and the cooling copper pipe are connected with a gas inlet and a gas outlet of the coal sample tank, and the cooling copper pipe is connected to a gas chromatograph.A heating layer is arranged outside the box body, electric heating wires are arranged in the heating layer, a heat preservation layer is arranged outside the heating layer, the electric heating wires are connected with a temperature raising programming controller, a temperature is arranged in the coal sample tank and is connected with a coal sample temperature data acquisition card, and the temperature raising programming controller, the coal sample temperature data acquisition card, the balance and the gas chromatograph are connected with a computer.The coal spontaneous-combustion characteristic determining device is high in automation degree, and test results are reliable.

The invention relates to a device for coal detection, in particular to a device for the simulation of coal spontaneous combustion on the basis of programmed temperature control. A stainless steel plate (3), an electrical heating tape (4), a heat insulation and preservation material layer (5) and a packaging iron sheet (6) are sequentially arranged from inside to outside between the inner wall andouter wall of a reaction tube (1); a coal-bearing pallet (7) is arranged at the bottom of the reaction tube (1); an air inlet pipe (8) is extended into an air cushioning layer (10) at the bottom of the reaction tube (1) via the wall surface of the reaction tube (1); an air outlet pipe (9) is led out from an air cushioning layer (11) at the upper part of the reaction tube (1); thermocouple temperature probes are distributed in the inner cavity of and between the inner wall and the outer wall of the reaction tube (1); and gas sampling points (15) and an SF6 (sulfur hexafluoride) gas injection point (16) are distributed in the inner cavity of the reaction tube (1). Based on the programmed temperature-control method, the device of the invention is capable of achieving the process of coal spontaneous combustion under two experimental conditions, i.e., adiabatic oxidation and accelerated oxidation, thereby determining the characteristics of coal in low-temperature oxidation more accurately.

The invention relates to a dynamic wind temperature control-based method for quickly testing the shortest spontaneous combustion period of coal, which relates to a coal test method. The method comprises the following steps: (1) removing a surface layer of newly-collected coal, and then breaking the coal to obtain a test coal sample for later use; (2) adding the coal sample into a reaction container to allow wind flowing through coal bodies to pass through the reaction container uniformly, and opening a PID control system to monitor the temperature variation of the coal bodies and wind currents hourly; (3) opening an oxygen concentration detection system to detect the change rate of the oxygen concentration of each characteristic point in the coal bodies; and (4) substituting characteristic parameters determined in an experiment in the process of coal spontaneous combustion in a demarcated mathematical model of the shortest spontaneous combustion period of the coal to calculate the shortest spontaneous combustion period of the coal. The test method can determine the shortest spontaneous combustion period of the coal quickly, simply and accurately under the adiabatic condition and test the shortest spontaneous combustion period of the coal scientifically and quickly, and is high in confidence level of test results.

Provided is a gas explosion coal seam permeability increasing extraction method in a borehole in the later period of induction extraction. The method comprises: inserting a gas extraction pipe (7) into a borehole; a down-hole negative pressure extraction main pipeline (1) and the pipeline of a three-way ball valve (5) being provided with a gas density monitoring device (2), a carbon monoxide monitoring device (3), and a temperature monitoring device (4), a gas extraction pipe being provided with a spark generator (6), when the gas density monitoring device monitors that gas density in the gas extraction pipe is in the range of 9%-10%, the spark generator switching on to make gas in the borehole blast; extracting gas in the borehole; when carbon monoxide density in the extracted gas is monitored to exceed a warming value or the temperature of the extracted gas exceeds the warming value, injecting water into the borehole to prevent coal spontaneous combustion. The method uses the natural attenuation characteristics of the density of a gas extraction borehole to induce repeated detonation, cracks of coal mass on the periphery of a hole wall are developed, and coal seam gas permeability is improved continuously. The method is suitable to be used for a high-gas low permeability coal seam.

The invention provides a method for collaborative governance of gas and coal spontaneous combustion of a fully-mechanized caving face with a single thick coal seam. The method is suitable for collaborative governance of gas and coal spontaneous combustion disasters of the fully-mechanized caving face with the spontaneous tendency, the single thick coal seam and large gas emission. Macromolecular air leaking stoppage materials are sprayed to air inlet and return gate roadways of the caving face to form an air leaking stoppage system. In the recovery process, high-order drill holes and grouting holes are alternately formed in the air return gate roadway side, and the high-order drill holes and the grouting holes are kept reasonably spaced to form a gas drainage and grouting system. Monitoring and prewarning systems are established at relevant positions of the caving face, the safety state of the caving face is monitored at any time, and all the systems collaboratively work to achieve the purpose of collaborative governance of the gas and coal spontaneous combustion disasters of the fully-mechanized caving face with the single thick coal seam. The method for collaborative governance of gas and coal spontaneous combustion of the fully-mechanized caving face with the single thick coal seam is scientific, effective, simple and easy to carry out, does not delay production, and can guarantee rapid and efficient exploitation of the caving face.

The invention discloses an inhibitor with sustained release property and a preparation method thereof, and the inhibitor is characterized by comprising the following steps of preparing a polymer emulsion by evenly mixing 10-20% of polymer, 79-89% of solvent and 1% of surfactant according to the percentage of the total weight of the prepared emulsion, further adding 4-9 times of the weight of the polymer emulsion of an inorganic salt type inhibitor, stirring for 2-3 hours at the temperature of 40-50 DEG C, drying an obtained product for 6-8 hours at the temperature of 60-80 DEG C, smashing and then obtaining the inhibitor product with the sustained release property. The preparation method is simple and easy to operate, the obtained product can be sustainedly released during the prevention and control process of coal spontaneous combustion of a mine, thereby prolonging the time of flame retardance; the residual polymer is covered on a coal layer, thereby also playing the roles of oxygen isolation and inhibitation; furthermore, the polymer can utilize waste plastics, and the preparation and the using process can not cause harm to environment, thereby having great application prospect.

The invention relates to a mining fire behavior early warning method and system based on multi-parameter cross-over analysis. According to the four stages of the spontaneous combustion process of coal, that is, the eremacausis stage, the fast oxidation stage, the vigorous oxidation stage and the spontaneous combustion stage and the low-temperature oxidation experiments of different types of coal samples, the threshold values corresponding to temperature and CO concentration in each stage are determined. The temperature, CO concentration, C2H4 concentration and C2H2 concentration in a coal mine fire behavior monitoring area are collected. The collected temperature and CO concentration are compared with the threshold values in each stage, the stage of the fire behavior of the coal mine fire behavior monitoring area is judged according to the comparison result, the C2H4 concentration and the C2H2 concentration, and therefore accurate early warning in each stage of the mining fire behavior is realized. Accurate early warning of the fire behavior in each stage of the spontaneous combustion process of coal can be achieved, the problem that under the condition that the stage of spontaneous combustion is undefined, firefighting measures are taken hastily and then a gas explosion accident is caused is avoided, and great significance in prevention of coal spontaneous combustion fire disasters is achieved.

The invention discloses phase change material temperature-sensitive coating as well as a composite retarder and a preparation method thereof. A temperature-sensitive phase change material is used as acoating shell, the composite retarder with high water content is directly and externally coated with a composite phase change material, and the composite material takes phase change materials such asparaffin and stearic acid as matrix, uses glass fibers, polypropylene fibers and the like as aggregates and is prepared from flame retardant materials such as magnesium hydroxide, chlorinated paraffin, expanded graphite and glass beads. The phase change material temperature-sensitive coating improves the hardness and ignition point of the phase change material, enables coal briquettes not easy tobreak when falling down, and not only overcomes the defect that the traditional fire preventing and extinguishing retarder is easy to fail, but also well maintains the properties of the retarder; furthermore, the phase change material is more sensitive to temperature rise and can be melted before the critical temperature of coal spontaneous combustion, so that the retarder in the coating can be fully released so as to inhibit the coal spontaneous combustion. The preparation system adopts a modular design, is simple in structure and easy to operate, and can be used for efficiently producing and processing the retarder for the coating.

The invention discloses a coal spontaneous combustion tendency identification method based on double-oxygen uptake. The coal spontaneous combustion tendency identification method comprises the following steps: putting a broken and filtered coal sample in a spiral reactor, putting the reactor in a set constant temperature furnace, introducing in dry air, determining oxygen concentrations at the outlet of the reactor under the conditions of 30 DEG C and 90 DEG C respectively, converting the physical oxygen consumption and the chemical oxygen consumption in every gram of coal sample in the low-temperature oxidation process respectively according to the change of the oxygen concentrations, and carrying out weight calculation through the two parameters to obtain a coal spontaneous combustion tendency determination index, wherein the larger the value of the index is, the easier the spontaneous combustion is. Through the obtained technical effect, the physical oxygen consumption and the chemical oxygen consumption in the low-temperature oxidation process are effectively combined to identify coal spontaneous combustion tendency, therefore, the disadvantage that the coal spontaneous combustion tendency cannot be comprehensively evaluated by a physical oxygen adsorption method singly depending on coal is effectively overcome. A double-oxygen uptake method can be used for identifying the coal spontaneous combustion tendency more scientifically and reasonably, the implementation method and the test process are easy and feasible, and the standard of classification is unified.

The invention discloses a spontaneous combustion classification early warning and active classification prevention and control method for mine coal. The method comprises the steps that (1), downhole environmental data is collected; (2), whether ethylene occurs in a downhole coal seam or not is judged; (3), whether the ratio of the change amount of carbon monoxide concentration and the change amount of oxygen concentration is less than the oxidation threshold value or not is judged; (4), whether to start the mine coal spontaneous combustion first-level early warning and implement active first-level prevention and control or not is determined; (5), the mine coal spontaneous combustion first-level early warning and active first-level prevention and control are carried out; (6), the mine coalspontaneous combustion second-level early warning and active second-level prevention and control are carried out; (7), the mine coal spontaneous combustion third-level early warning and active third-level prevention and control are carried out; (8), whether the real-time ratio of ethylene concentration value and ethane concentration value in the downhole coal seam reaches the maximum value or notis judged; and (9), the mine coal spontaneous combustion fourth-level early warning and active fourth-level prevention and control are carried out. The method uses multiple gas indexes to consider therelationship between the change of oxygen concentration and the degree of spontaneous combustion of coal, and avoids an early warning method by means of single index gas, comprehensively and quantitatively analyzing the degree of spontaneous combustion of the coal is achieved, and the accuracy of the early warning is improved.