A gas drainage method for fully mechanized caving face in soft surrounding rock

Abstract

The invention discloses a method for gas extraction on the weak surrounding rock fully mechanized caving face, and the method is suitable for a mine where the gas concentration of the caving face is liable to overrun in the top coal caving process of the thick coal seam weak surrounding rock fully mechanized caving face. A vertical pipe is constructed to the upper portion of a coal seam through a pneumatic anchor rod driller at the upper corner of an air return roadway of the fully mechanized caving face, the gas extraction vertical pipe is arranged in the coal seam, a large amount of gas generated in the top coal caving operation process is extracted timely, and accordingly the gas concentration of the fully mechanized caving face is reduced; the problem that under the condition of weak surrounding rock, hole-forming fails when oblique-crossing layer penetrating pre-extracting drilling is constructed on the upper portion of a goaf in the air return roadway is solved; the large amount of gas rushing out of fully mechanized caving face coal masses in the top coal caving operation process can be extracted, so that the gas concentration of the caving surface and the upper corner is reduced effectively; and meanwhile within the period of caving surface advancing, the gas of the goaf behind the caving face can be further extracted, the emission amount of the gas in the goaf is reduced, and the gas concentration of the caving surface is reduced. The structure is simple, mounting is convenient, operation is easy and convenient, and practicability is high.

Description

technical field [0001] The invention relates to a gas drainage method for fully mechanized caving working faces with soft surrounding rocks, and is especially suitable for mines where the gas concentration at the working faces easily exceeds the limit during top coal caving in the fully mechanized caving working faces with soft surrounding rocks in thick coal seams. Background technique [0002] Coal mine gas is the gas generated by vegetation in the process of coal formation, also known as coalbed methane, which is mainly stored in the pores and fissures of coal seams or rock formations, and exists in free and adsorbed states in coal or rocks. Gas is not only a resource but also a hazard. At present, gas accidents are the most frequent, most dangerous and most destructive disasters in the coal mine production process. [0003] For thick coal seams (5-15m, underground mining), top-coal caving mining technology has significant advantages such as shortening the coal mining pre...

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Problems solved by technology

[0006] Due to the soft surrounding rocks of fully-mechanized caving faces in some coal mines in my country, according to the conventional gas drainage method, when obliquely drilling into the upper coal and rock of the goaf near the upper corner of the return airway, there are often drill pinches, Drill sticking, shrinkage and collapse, etc., make oblique drilling difficult (can) form holes, resulting in poor gas drainage effect, easy gas exceeding the limit, and seriously threatening the safety of staff and equipment

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