Coal mine gas prediction and prevention

Gas outburst prediction

1. Prominent hazard area prediction Based on the gas geostatistical analysis method and the comprehensive index method, the radio wave perspective technology of the dangerous area is experimentally studied, and the variation of the absorption coefficient of the radio wave in different coal-rock media is used to detect the prediction area. Structural anomaly zone, coal seam thickness change zone, coal seam strength change zone, gas enrichment zone, etc. According to the results of the fluoroscopy, combined with the geological statistical analysis of the gas and the changing rules of the work-predicted indicators, the expert system software is used to comprehensively analyze and judge the outstanding danger of the area. The methane detection alarm is used to measure the methane concentration in the vicinity, and a low-concentration methane sensor is installed in the roadway to reach the methane alarm point for timely evacuation.

2. The prediction experiment of the dangerous dangerous working face shows that the electromagnetic wave signal is generated in the coal rock layer during the loading process, and the signal amplitude is related to the external load and the degree of damage of the mechanical properties of the coal rock. Since coal and gas outburst are also a mechanical process in which coal and rock are damaged by load, the electromagnetic radiation signal generated by the destruction process can be used to predict the protrusion. The characteristics of electromagnetic radiation signal change are basically consistent with the prominent hazard prediction index, which is sensitive to the gas dynamic phenomenon during drilling. It is an ideal non-contact method to predict the protrusion using electromagnetic radiation signal variation characteristics.

Production mine gas disaster prevention and control method

1. Seriously study advanced experience and earnestly achieve “five timely”. The “five timely” management measures for timely construction, timely drilling, timely sealing, timely filling and timely filling were adopted for the roadway drainage drilling field, which prevented the accumulation of gas in the drilling field. In terms of drilling and measuring the size, according to the actual work needs, the mine has set up a gas control office, which is responsible for the inspection of gas effects, strictly implementing the separation of “dry and pipe”, and clarifying the joint measures of gas receivers and ventilation zones. To ensure the authenticity of the scale, at the end of the month, the Gas Control Office is responsible for summarizing the supervision and inspection data, and strictly implementing the anti-burst effect test, effectively checking the drilling scale and effect inspection.

2. Take precautionary measures to strengthen gas site management. Strictly implement the principle that the hole must be sealed, the sealing hole must be strict, and the sealing must be pumped. The automatic water dispenser is actively promoted to strengthen the management of the water discharge work. On the basis of ensuring the suction negative pressure and the concentration of the pumping, the gas is further strengthened. On-site management, through strict implementation of the mining team captain's class three inspection three reporting system, to eliminate the phenomenon of empty class missed inspection, false inspection, false reporting. At the same time, once the methane concentration reaches 0..8% in the mining face, the methane power-off meter will automatically cut off the power to protect workers' safety.

3. Adhere to the necessity of pumping, pumping and digging, and strictly implementing the gas comprehensive management access system. Gas drainage measures were taken at the first place of coal excavation to prevent gas from exceeding the limit. The gas displacement, pumping capacity, content and drainage rate of the spare surface were carefully calculated. The experience was collected in accordance with the requirements of the gas drainage rate. Production can be organized under the condition that the system is sound. Through the implementation of measures, the occurrence of gas overrun accidents during the mining process of the working face will be eliminated.

4. Adhere to the "suspicious exploration, exploration, exploration, and exploration" to prevent the occurrence of coal seams. Further implement the “five-in-one” comprehensive prevention and control measures for faults and gas anomalies. That is: the geological department strengthens the geological prediction and forecast, and provides the forecast data in time; the abnormality report is found in the anti-burst area during the drilling process; the excavation unit finds the geological, mine pressure, gas abnormality, and immediately stops the head; the ventilation area can cut off when the gas exceeds the limit Excavation of the electrical power supply in the roadway and its return air system; the gas detector found that the gas was abnormal and immediately withdrew the personnel. It is clear that the chief engineer of the mine will timely organize the formulation of “safety measures for the implementation of faults (or gas anomaly zones)”. By adopting targeted measures, the phenomenon of gas overrun caused by faults and gas anomalies is eliminated.

5. Strengthen the gas management of the old pond corner and the heading face of the coal mining face. In the management of the coal mining face, the management of the old pond corner is strictly advanced, and the coal raft is used to fill the unfilled space; the front support and roof management are strengthened in the management of the excavation face to prevent the coal roof from falling. The roof collapse caused the gas overrun accident; for the comprehensive excavation construction, the coal cutting process was changed, from the original bottom up to the current one from the top to the bottom, and the footage was balanced; for the blasting face, shallow blasting was adopted. A series of targeted measures, in essence, to eliminate gas overrun accidents.

Coal mine safety is a multi-factor, multi-link, dynamic and complex system engineering. All production and operation of coal mines must put safety work first. This is not only determined by the special nature of coal mine production, but also the inherent requirement of improving the economic efficiency and stable development of enterprises under market economy conditions. To a certain extent, safety itself is the biggest benefit of coal mines. Only by strictly following the "safety first" production policy, correctly handle the relationship between safety and reform, safety and production, safety and efficiency, and rely on scientific progress to establish A modern coal mine safety production guarantee system can promote the vigorous development of the economic benefits of the coal industry.

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