High-level roadway pressure relief and gas drawing-out top coal caving mining method for extremely thick and hard coal bed

Abstract

The invention discloses a high-level roadway pressure relief and gas drawing-out top coal caving mining method for an extremely thick and hard coal bed, and belongs to the technical field of top coalmining. The method comprises the following steps: arranging a caving mining face at the bottom of the extremely thick and hard coal bed, respectively and obliquely arranging a lower linking way and anupper linking way which are led to the top of the extremely thick and hard coal bed from a caving mining face transportation way and a caving mining face air return way, and tunneling a group of parallel high-level roadways at the top of the extremely thick and hard coal bed in a spacing manner, communicating the high-level roadways through linking ways, arranging adjustment fans in the linking ways to control ventilation, arranging high-level gas drawing-out pipes and drilling sites in the high-level roadways, downwards constructing drilling by using the drilling sites, arranging liquid carbon dioxide blasting generators in drilled holes, and arranging the carbon dioxide blasting generators in front of the caving mining face. The high-level roadway pressure relief and gas drawing-out topcoal caving mining method for the extremely thick and hard coal bed realizes safe mining of the mining face and high production efficiency; moreover, liquid carbon dioxide is used for blasting, so that the blasting process is intrinsically safe; furthermore, gas can be transferred and drawn to the high-level roadways conveniently.

Description

Technical field: [0001] The invention relates to the technical field of top-coal caving mining, in particular to a method for pressure-relieving and gas-caving top-coal caving mining in a high-level process lane in a huge thick hard coal seam. Background technique: [0002] The geological conditions of my country's coal seams are complex. As a high-yield and efficient mining technology, top-coal caving mining has been popularized and applied to a certain extent. However, the low coal recovery rate of the top-coal caving mining method and the difficulty of gas control in the working face are the constraints that affect its development. Especially when the top coal caving is mined under the condition of extremely thick and hard coal seam, the problem is particularly prominent. [0003] At present, the technical methods of coal seam enhancement and pressure relief proposed by domestic scholars mainly include explosive deep hole pre-splitting blasting, hydraulic fracturing, hydra...

AI Technical Summary

Problems solved by technology

Due to the defects of some anti-reflection technologies and process methods, the effect of many technical measures is not ideal

[0004] Patent document CN201610263144.5 discloses a method for caving top-coal in weakened hard coal seams based on carbon dioxide blasting, which uses carbon dioxide blasting to weaken the hard top-coal, so that the top-coal release rate is increased by 20% to 30% compared with that before roof fracturing , but the drilling at the roof between the two hydraulic support beams near the coal wall has a greater impact on the production of the working face

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