The coal seam dust has strong explosiveness, and the explosive index of coal dust is 35.01%. If the coal dust does not pay attention to strengthen the comprehensive dust prevention during the production process, the coal dust in the working face will fly or the coal dust in the roadway will accumulate, and one of the following situations will be encountered. It may cause a coal dust accident: 1. Gas explosion or combustion causes coal dust explosion. 2. In violation of the regulations, the cannon mud filling does not meet the requirements, the use of non-coal mine explosives and deferred detonators, and the passage of the roadway through the blasting cannons cause coal dust explosion. 3, the use of non-explosion-proof electrical equipment, improper cable laying, or the use of non-flame-retardant cables, the use of explosive electrical equipment, illegal maintenance of electrical equipment, mining lamp management and improper use of electrical accidents caused by coal dust explosion. 4, open flame (such as underground electricity, gas welding, etc.) caused by coal dust explosion. 5. Improper command during the disaster relief process caused an explosion. 6, metal friction sparks caused by coal dust explosion. 7. Lightning strikes cause coal dust explosions (lightning can be transmitted to the well through the rails to induce sparks). 8. When the shearer cuts the clamp, it will generate friction sparks, which may cause coal dust explosion. To this end, it is necessary to strengthen mine dust control management and strictly follow the specified dust measurement: 1. The squadron must be assigned full-time personnel (at least 2) for dust measurement. The measured data must be accurate and reported to relevant departments and mine leaders in a timely manner. 2. The mass concentration of total dust in all dust-producing sites on the ground and on the ground must be measured monthly. The specific ground measurement period is January and the downhole measurement period is 15 days. Determination of the concentration of respiratory dust: The mining surface is measured once every 3 months. 3. The team must establish a dust measurement record manual, a dust measurement record account and a dust measurement report. The report must be reported within 3 days after the completion of the report. The dust measurement board must be established at the dust measurement site and must be filled in time. 4. The dust measuring instrument must carefully check the dust measuring instrument before dust measurement, so that the surface is clean, the accessories are complete, the electric keys are sensitive and reliable, and the electricity must be sufficient before the well. 5. Select the dust to be measured during the normal production time every month. When measuring dust, the sampling port of the instrument must meet the wind flow. For continuous dust production, the sample should be sampled after the production reaches the normal state for 5 minutes. Adjust at around 20 liters / minute. 6. Dust-measuring points are generally selected for suction dust analysis within the range of contact personnel activities (within a height of 1.5 m from the bottom plate). 7. The selection of dust measurement position is determined at the fully mechanized mining face according to the current actual selection of mines in the return airway from the upper 10 to 15m; the comprehensive excavation working face is selected after the pedestrian side of the comprehensive Excavator. 5m place measurement; the yard stone gate and other roadway blasting are selected at the location where the workers work after the workers enter the work surface after the shooting. The dust concentration measurement at the transfer point of the belt conveyor was measured at 5 to 10 m from the return air side of the conveyor transfer point. 8. In order to ensure the minimum dust concentration on the surface of the main return roadway, mine and mining area total return airway wall, it is stipulated to flush once every half month, and the roadway for mining and excavation work face needs to be flushed once a week. Section 2 Measures to Prevent Coal Dust Explosion 1. In accordance with the "Procedures", ensure that the mine dust and water sprinkler pipeline is perfect, install spray facilities as required to purify the dust in the wind flow; and ensure downhole water, such as flushing lanes and wet drilling, and maintain well-explosion-proof facilities. . 2. In the case of permitting conditions, measures such as coal seam water injection, watering (slurry) in the goaf and water cannon mud are used to reduce the amount of coal dust generated during mining. 3. Measures such as spray dust reduction and air purification at locations where coal dust is easily generated to reduce the concentration of coal dust in the underground air. 4. The wind speed of the roadway is closely related to the dust content in the air. When the wind speed is too small, the suspended coal dust cannot be taken away. When it is too large, the dust will be blown up and its concentration will be increased. Therefore, from the perspective of dustproof requirements, the downhole wind speed is rationally designed and guaranteed to be supplied according to the design to prevent coal dust from flying. 5. The coal dust deposited on the roadway and around the cable and equipment will once again be swelled if it is subjected to vibration or impact, which will create conditions for the coal dust explosion. Therefore, it is necessary to organize personnel to regularly clean and flush the coal dust on the roadways, cables and equipment according to the system. In addition, flushing coal and coal (rock) watering, and preventing coal spills during transportation are also measures to reduce coal dust. 6. The internal and external spray of the mining machinery and the spray after the bracket must be complete and intact to ensure normal use during cutting and coal mining. 7. Each reloading point of the transportation system must have a perfect spray dust reduction facility, and it is sensitive and reliable, and is used normally. 8. The incoming and return air flow of each mining face, the inlet and return air flow of the mine and mining area must be provided with a purified water curtain, and ensure normal use. 9. The coal dust in the surface coal flow system and the selective drafting workshop must be managed strictly according to the requirements of the underground to ensure regular cleaning and spray sprinkling when pulling coal. 10. Strictly set up and improve the explosion-proof facilities in accordance with the provisions of the Regulations to curb the expansion of coal-dust explosion accidents and reduce their hazards. 11. All personnel entering the well must carry a self-rescuer. Otherwise, it is strictly forbidden to enter the well. Treatment measures after coal dust explosion in the third quarter 1. When a coal dust accident occurs, the site personnel should immediately organize the personnel in the disaster area and the personnel in the threatened area to evacuate the site and immediately report to the dispatching room. The dispatching office will inform the relevant mining leaders according to the “list of units and personnel that must be convened after an accident†(Schedule 1). 2. The mine leader immediately organized an ambulance inspection to accurately identify the location, nature, and scope of the accident, the number and location of the personnel in distress, and the ventilation and ventilation conditions of the roadway to determine an accurate basis for the disaster relief plan. 3. During the disaster relief process, special personnel should be inspected to check the coal dust and observe the airflow in the fire zone. When there is a danger of explosion, the disaster relief personnel must immediately evacuate to a safe area and take measures to eliminate the explosion. 4. In the process of disaster relief, the power supply to the disaster area should be cut off to prevent a secondary explosion. 5. Rapidly organize rescue of people in distress. 6. Ensure that the ventilation and ventilation systems and airflow conditions within the damaged recovery should be quickly restored without the risk of secondary explosion.
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Mine coal dust explosions, analysis and measuring dust