Method for top coal caving mining of pressure unloading by blasting and gas drainage of huge thick and hard coal bed

Abstract

The invention discloses a method for top coal caving mining of pressure unloading by blasting and gas drainage of a huge thick and hard coal bed, and belongs to the technology field of top coal cavingmining. The method comprises the steps that a top coal caving working face is arranged at the bottom of the huge thick and hard coal bed, a lower connecting roadway and an upper connecting roadway are obliquely arranged on a conveying roadway and a wind return roadway of the top coal caving working face correspondingly and communicate with the top of the huge thick and hard coal bed, a set of parallelly-arranged high-level process roadways is tunneled at intervals along the top of the huge thick and hard coal bed, the high-level process roadways communicate with one another through a set of connection roadways arranged at intervals, the connection roadways are internally provided with adjusting air windows for controlling ventilation, high-level gas drainage pipes are arranged in the high-level process roadways, drill sites are arranged in the connection roadways, construction is conducted downwards for drilling by utilizing the drill sites, liquid carbon dioxide blasting generators are arranged in drilled holes, and the carbon dioxide blasting generators are arranged in advance compared with the top coal caving working face. According to the method for top coal caving mining of pressure unloading by blasting and gas drainage of the huge thick and hard coal bed, safe mining of the working face is achieved, the production efficiency is high, safety is intrinsically achieved byadopting liquid carbon dioxide for blasting, and gas is transported and drained to the high-level process roadways advantageously.

Description

Technical field: [0001] The invention relates to the technical field of top-coal caving and mining, in particular to a method for blasting and pressure-relieving and draining gas and top-coal caving in huge thick and hard coal seams. 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, hydraulic punch...

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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