Method for statically fracturing over-hard rock fault on coal mining working face of underground coal mine

Abstract

The invention discloses a method for statically fracturing an over-hard rock fault on a coal mining working face of an underground coal mine, and relates to the technical field of coal mine underground mining. The method comprises a mining roadway, a coal seam, a hard rock fault, and a working face roof rock stratum; a fracturing hole is formed in the top of the hard rock fault; and a static fracturing cartridge is arranged in the fracturing hole. According to the method for statically fracturing the over-hard rock fault on the coal mining working face of the underground coal mine, the hard rock fault method is adopted, so that drilling holes do not need to be additionally dug to serve as free space of static fracturing, the drilling procedure needed by static rock breaking is omitted, and only one-time static fracturing procedure needs to be completed in the whole rock breaking process. After fracturing, a coal cutter can smoothly cut the hard rock fault, and the rock is broken by using the static fracturing cartridge instead of static fracturing slurry, so that the static fracturing efficiency is ensured. The provided method has been successfully applied to the over-hard rock fault coal face of a coal mine in the Guijia Bay of an elm city in Shaanxi province at the beginning of the year.

Description

technical field [0001] The invention relates to the technical field of underground mining in coal mines, in particular to a method for statically cracking a hard rock fault in an underground coal mining face of a coal mine. Background technique [0002] In the field of underground coal mine mining, the coal mining face often encounters hard rock faults during the advancing process, and the rock formation at the bottom of the working face protrudes toward the coal mining face under the action of structural stress, which hinders the normal coal mining process of the coal cutter. This phenomenon occurs more and more frequently in the mining areas of northern Shaanxi in my country. Normally, it is difficult for coal cutters to cut the hard rock mass in the fault of the coal mining face. The hard rock fault can only be pre-cracked and broken by drilling and blasting. Carry out normal coal mining procedures. However, provinces such as northern Shaanxi, Xinjiang, and Inner Mongolia h...

AI Technical Summary

Problems solved by technology

[0005] Static fracturing technology currently has certain applications in the field of underground coal mining in China, including the treatment of hard roofs in the triangular area at the end of the working face, the enhancement of high-gas coal seams, the expansion of roadways, the replacement of explosive blasting technology for rock roadway excavation, and the treatment of bottom drums in roadways, etc. , but it is rarely used in hard rock faults in over-mining working faces. Gui Liangyu published a paper titled "Application of Static Fracture Technology in Fully Mechanized Over-mining Faults" and proposed a method of processing work through static fracturing The method of face hard rock fault, this method first needs to artificially excavate a large-diameter borehole in the fault rock mass as a free space for static fracturing; Finally, use a pick to remove the broken rock mass to form a larger free space; finally, excavate the caving hole again around the charging hole, pour static fracturing slurry for secondary rock breaking, and assist the coal cutter to cut the hard fault. The method has the following disadvantages: 1) the drilling process is complicated, and it is necessary to use a drilling rig to excavate a large-diameter borehole and a pneumatic drill (or anchor drill rig) to excavate the charging hole and the caving hole; 2) the rock-breaking process is cumbersome, and two static rock-breaking processes need to be completed (Static fracturing is carried out in the charging hole and caving hole respectively); 3) Before the coal cutter cuts, it is necessary to use a pneumatic pick to remove part of the broken rock mass, which increases labor costs and time costs; 4) Using static fracturing When the grout is used for static rock breaking, the grout poured into the fracturing hole is easy to lose along the cracks in the fault rock body, reducing the static rock breaking efficiency. Therefore, in the field of underground coal mining, there is an urgent need for a safe and efficient treatment of hard coal mining faces. The method of rock faulting, for this reason, we propose a method of statically cracking hard rock faults in coal mining working faces in underground coal mines to solve the above problems

Images