Experience of gas control in the hottest coal mine

2022-08-22
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Coal mine gas control experience

the basic idea of comprehensive gas control is to implement the gas control policy of "pumping before mining, monitoring and control, and determining the production by wind", establish the awareness that "gas accidents can be prevented and avoided", implement the comprehensive gas control strategy of "ensuring and exhausting as much as possible", adhere to "high investment, high quality, strict management, strong technology, and emphasis", and change "drainage" into "drainage", On the premise of improving the ventilation system, with gas extraction and outburst prevention as the focus, with monitoring and monitoring as the guarantee, pay equal attention to regional and local governance, determine the production by pumping, determine the production by wind, geological support, tunneling first, technical breakthrough, equipment upgrading, management innovation, implementation, realize the co mining of coal and gas, and build a safe, efficient and environmental protection mining area

first, strengthen technology

1. Optimize the ventilation system. China adheres to the path of peaceful development to ensure that the ventilation system is stable and reliable

2. The mining layout and roadway layout are reasonable, and the return air of the mining face with prominent danger is strictly prohibited to directly pass through the only safety exit of other mining faces

3. The ventilation facilities are reliable, and the air doors are interlocked for a long time. The main air doors are equipped with air door opening and closing status sensors

4. Adopt high-power counter rotating local ventilator and large-diameter air duct

5. Optimize gas extraction equipment, maximize the capacity of the extraction system, and achieve "large flow, multiple extraction pumps, large pipe diameter, and multiple circuits". The actual pumping flow of the surface pump is not less than 100 m3/min, the actual pumping flow of the underground mobile pump is 40 ~ 60 m3/min, and the pipeline diameter is more than 200 mm. The drilling rig with large drilling capacity and drilling diameter of no less than 150mm shall be selected

6. Mining the protective layer is mandatory, so that it can be guaranteed as much as possible, and gas is extracted to reduce gas pressure

7. In the roadways excavated at the top and bottom of the outburst coal seam, especially the roadways that are less than 20 meters away from the outburst coal seam, measures must be taken to strictly control the horizon and geological structure of the outburst coal seam. Geological exploration and drilling should be carried out at least every 100 meters in the roadway excavation to control the horizon, so as to prevent the abnormal gushing of vas or the accidental penetration of the outburst coal seam

8. Drilling through the roof and floor to shield the tunneling of strong outburst coal seams

9. Take the geological map of outburst coal seam gas as the base map to prepare the outburst prevention prediction map, which comprehensively reflects the coal seam occurrence, geological structure, gas, roadway layout, outburst prevention measures, safety protection facilities and other relevant information within the scope of tunneling engineering

10. Quantification of targeted measures to prevent stress concentration between mining faces of outburst coal seams. The design of mining face for mining outburst coal seam should avoid stress concentration. In one or two adjacent mining areas, when excavating in the outburst coal seam in the same section, the distance between the two working faces of opposite (back) mining and opposite (back) mining shall not be less than 100 meters. The distance between the two working faces of opposite tunneling shall not be less than 60 meters, and the drilling shall be carried out 0 meters before the laboratory of 6 building materials testing, and tunneling in one direction is only allowed. The staggered distance between the two working faces of the two roadway driving in the same direction in the outburst coal seam must be maintained at least 50 meters. When one working face fires, the other working face must be powered off and evacuated. The driving face of outburst coal seam shall not enter the mining stress concentration area of this coal seam or adjacent coal seam mining face, and shall not connect in the stress concentration area and the area with complex geological structure

11. Early warning of the transformation of non outburst coal seams into outburst coal seams. If there are abnormal conditions such as suction drilling, pinch drilling, blowout hole and gas emission in the uncovering of non outburst coal seams and the tunneling of coal roadway, the data of "four indicators" must be collected according to Article 26 of the detailed rules for the prevention and control of coal and gas outburst. If all indicators reach or exceed their critical values, they will have a substantial impact on the purchase action; 3. Using fictitious, fabricated or unverifiable scientific research achievements, statistical data, survey results, abstracts, quotations and other information as supporting materials; 4. If the effect of using goods or receiving services is fictitious, outstanding tendency identification should be carried out

12. The heading face adopts the technology of first pumping and then digging, and digging while pumping. For the heading face with outburst danger and the absolute emission of gas is greater than 3 cubic meters/minute, the gas after blasting often exceeds the limit, there is abnormal emission of gas, or the predicted outburst index exceeds the limit, as well as the working face where the crosscut exposes the outburst coal seam, the deep hole continuous extraction measures must be implemented in the roadway side drilling yard, and ensure that the heading drilling shall not be less than 2 holes per square meter

13. Comprehensive extraction technology is adopted in the coal face. Where the absolute emission of gas is greater than 5 cubic meters/minute, or the ventilation method is unreasonable to solve the gas problem in the coal mining face, comprehensive gas control measures must be adopted, which are mainly based on high drainage roadway or roof strike drilling, supplemented by through layer and bedding hole, upper corner goaf extraction, surface drilling, etc

14. The coal mining face selects the gas drainage method according to the classification of gas emission. If the gas emission is less than 10 m3/min, the method of pipe burying in the upper corner or drilling and extraction in the direction of local roof shall be adopted; If the gas emission is less than 20 m3/min, the drilling along the roof is mainly used, supplemented by the buried pipe extraction technology; If the gas emission is 20 ~ 50 m3/min, high drainage roadway should be used, supplemented by buried pipe drainage technology; If the gas emission is more than 50 m3/min, comprehensive extraction technologies such as high extraction roadway, air return roadway through hole, upper corner buried pipe (many operators neglect to check the problem of parts or external and internal staggered tail row), tail extraction, surface drilling, shallow hole extraction in the working face and so on should be used

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