Cause analysis and Countermeasures of gas explosio

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Cause analysis and Countermeasures of mine gas explosion accident

the necessary conditions for mine explosion are: the concentration of methane exceeds the lower explosion limit, the concentration of oxygen is not less than 12%, and the existence of ignition source. Therefore, the explosion causes are mainly analyzed from three basic conditions: oxygen condition, gas accumulation and fire source. In addition, to reduce fuel consumption and emissions, measures are not implemented, and management loopholes are also the main reasons for explosion accidents

(1) mine ventilation management is poor, and mining operations are carried out in violation of laws and regulations. The main manifestations are: unlicensed production in the mine, the use of single eye wells, natural ventilation, and production with super ventilation capacity. Using series ventilation, diffusion ventilation and circulating air, a reasonable, stable and reliable ventilation system has not been formed. The goaf and blind roadway are not treated in time, the gas accumulation treatment method in special places is wrong, and the gas is discharged in violation of regulations, leaving hidden dangers for the main purpose of the impact sample notch broach. There is a phenomenon that the ventilator up and down the shaft cannot realize the automatic collapse of "double fans and double power supplies", and the ventilator is not started and stopped according to the regulations. The mine ventilation management regulations were not implemented, and the air could not be distributed as needed. The staff opened and closed the underground air door at will, resulting in short circuit of air flow or delayed repair after the ventilation facilities were damaged. Some local ventilation management is not in place, the air duct is disconnected and broken, and the treatment is not timely, resulting in the air volume and wind speed not meeting the requirements, resulting in the breeze operation of the heading face

(2) the implementation of mine gas inspection and monitoring system is not strict. In the actual production process underground, the number of underground gas inspectors is not enough because they are not equipped according to the regulations, and there are often empty shifts and missed inspections. Some mine gas inspectors have not received formal training and education, work without certificates, have low ideological awareness and professional and technical quality, have weak heart, do not check and report according to the regulations, and even make false records. Some mines are not equipped with gas monitoring system, which can not continuously monitor the gas situation of underground mining face for 24 hours. Some mine gas monitoring systems are installed unreasonably, problems are not repaired in time, and even the probe value is adjusted arbitrarily by fraud, so that the underground monitoring system can not operate stably and accurately monitor data, and the power cannot be cut off when the gas exceeds the limit

(3) gas prevention and drainage measures in high outburst mines are not implemented in place, and low gas mines do not pay attention to gas management. Some high gassy and outburst mines did not seriously implement gas prevention measures and "four in one" outburst prevention measures, resulting in coal and gas outburst accidents. Some high outburst mines did not build gas drainage system according to the regulations, or although there was a gas drainage system, the drainage work was not carried out seriously, resulting in poor drainage effect, the drainage time could not meet the requirements, and the gas often exceeded the limit during mining operations. In addition, some low gas mines do not have corresponding gas prevention measures and regulations, or although there are measures and regulations, they are not implemented carefully. Statistics show that serious gas explosion accidents will still occur in low gas mines due to ideological paralysis and lax management

(4) shooting against rules or it can be regarded as the underground fire of high-quality equipment. During the blasting operation, the blast hole is not filled with water cannon mud according to the regulations, and even the water cannon mud is charged with combustible materials such as pulverized coal. The minimum resistance line of the blast hole is not enough, or the unqualified busbar is used for exposed blasting. Use unqualified explosives and detonators to shoot against regulations. In some mines, the goaf and old lanes are not closed in time and the sealing management is not strict, resulting in spontaneous combustion of coal and re ignition of fire areas, leading to open fires

(5) the management of mine power supply system is not strict, and sparks are generated, resulting in gas explosion accidents. In some mines, the underground lighting and electromechanical equipment selection are not in line with the regulations, and the management of electrical equipment is disordered, resulting in electrical explosion or live line operation. The stray current generated by the electrical circuit causes gas explosion accidents, and sometimes the belt friction and fire will also cause gas accidents. In addition, sparks generated by the impact or friction between rocks, rocks and metals, metals and metals, and electrostatic sparks generated by polymer materials may also cause gas explosion accidents

(6) the understanding is not in place and the system is not implemented. Some cadres, workers and gas managers have weak safety awareness and fail to seriously implement gas prevention measures and rules and regulations. In particular, in some small coal mines, employees carry fireworks to smoke underground, use electric welding without authorization, compare the fire welding with the old and new national standard test conditions in Table 3, and wear chemical fiber clothes to enter the well. These may cause gas explosion accidents

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