Ultra-Deep Coal Mining Vertical Shaft To Crack The Support Problem

 Ultra-Deep Coal Mining Vertical Shaft To Crack The Support Problem

  A few days ago, a group company improved the design of cyclic step of over-head support, which solved the problems of roof crushing caused by repeated support. This process is the first time to be applied in the domestic extra-large deep vertical shafts, and has high popularization value.

　　As the largest mine, a coal mine coal quality and the conditions of existence in the province, and comprehensive discharge of the second area of the 1302N working face is one of the best: the average coal thickness of 9.4 meters, working face length of 258 meters, the length of the strike length of more than 2,500 meters, it can be said to be a huge scale of the underground coal treasure trove. "If the mining of other coal mines in the province is a dish of small dishes, that 1302N is called a meal," said the relevant person in charge of the mine, since the formal mining in 2012, the coal mine in the 1302N workings on the application of the world's most advanced technology and equipment, and strive to this plate of "big meal"! "Eat fast, eat clean.

　　However, the process of eating a big meal is not so easy. 1302N working face is deeply buried, and the working face under the flat lane adjacent to the mining area, the overlying rock pressure and the lateral stress of the mining area is large. In addition, due to the softer coal quality of the face, the roof plate is repeatedly supported by stent pulling and lifting in the process of digging, which leads to the fast sinking of the roof plate of the roadway in the section of over-advance support, easy to break, and the deformation of the two sides of the roadway is large, and the large-area coal dropping often occurs in the process of advancing, which is very easy to cause the injury of the coal dropping and the accident of burying the machine. The pile of fallen coal not only causes narrow space in the roadway, but also makes it difficult to push forward the support, and the pile of coal treatment progress is slow, which greatly affects the coal production.

　　"The most effective way to solve this problem is to increase the propping distance." The company's technicians explained that this on the one hand reduces the damage of the support to the roof plate, and on the other hand expands the coal mining space and improves the work efficiency. However, the expansion of the support area is more likely to cause the collapse of the frame accident. The team worked with the manufacturer to design and process a large-diameter double-expansion push cylinder that matches with the existing bracket, replacing the original single-section push cylinder, which improves the integrity of the top plate between the anchoring frame and the over-arching frame, reduces the degree of damage to the top plate of the roadway, and reduces the workload of the anchoring frame's forward movement, which is effective after the practical feedback from the field. Then, the team designed to replace and rectify all the supporting oil cylinders, balancing jacks and liquid supply and return pipelines in the over-arching section of the lower level alley, so that the cyclic distance of the over-arching section of the lower level alley was raised from 0.8 meters to 1.6 meters. In January this year, the process was formally applied to the underground coal production face, after more than two months of practice has received good results, the roof is easy to break, support difficult problem has finally been solved.

　　Up to now, 1302N working face over the front bracket basically eliminated the phenomenon of crushing bracket, on average, can reduce the impact of accidents nearly 5 hours per month. According to the estimation, only this one working face can produce nearly 110,000 tons of coal a year, and increase the sales income of nearly 80 million yuan. The process has a wide application space in similar coal mines across the country, especially in thick seam coal mines in Inner Mongolia and Xinjiang. At present, the technology is being prepared to be popularized and applied in the company's 2302S working face, and the comprehensive system optimization of the comprehensive working face based on this innovative concept is also under research.