Safe and efficient fully-mechanized mining method for thin coal seam under two hard conditions

Abstract

The invention discloses a safe, efficient and high-yield fully-mechanized mining method for a thin coal seam under two hard conditions. In the method, an inclined longwall retreating mining method is adopted; an end part beveling feed mode is adopted; coal dropping and coal loading operations on a working face are completed by one double-drum coal mining machine; and a two-way coal cutting mode is adopted in the case of smaller slope, and a one-way coal cutting mode is adopted in the case of greater slope. In the invention, a two-leg shield support is utilized as a hydraulic support for the working face, and meanwhile a hard roof is weakened by a forced caving mode: initial caving holes are arranged at the positions on an upper gate road and a lower gate road of the working face 25m away from a cut hole; after initial caving of the working face, a first group of periodic caving holes at intervals of 30m are arranged on gate roads at head and tail parts; and forced caving are stated toimplement at the position 85m away from the cut hole. The method has the advantages of strong practicability and high reliability; and by means of the method, the purposes of high safety, high yield and high efficiency are achieved, the mining rate of the thin coal seam is accelerated, the scientific and reasonable coordinated mining is realized, the recovery rate of mine resources is improved, and the spontaneous combustion hidden danger of an underground coal seam is lowered.

Description

technical field [0001] The invention relates to the field of coal mining, in particular to a fully mechanized mining method for thin coal seams under two hard conditions. Background technique [0002] According to the thickness of the coal seam, the thickness of 0.8-1.3 m belongs to the thin coal seam, and the thickness less than 0.8 m belongs to the extremely thin coal seam. my country's coal seam reserves are large and diverse. Among them, the recoverable reserves of thin and extremely thin coal seams are about 6 billion tons, accounting for about 19% of the country's total coal reserves. The output only accounts for 10.4% of the total output, which is far lower than the proportion of reserves, and the proportion of output has a further downward trend. The problem of thin coal seam mining has become more and more prominent, and it has become an unavoidable practical problem. Coal is a non-renewable resource. When the mine infrastructure is completed, the resources in the...

AI Technical Summary

Problems solved by technology

Because of low efficiency and high excavation rate, its mining cost is significantly higher than that of medium-thick coal seams, but its economic benefits are not as good as those of medium-thick coal seams

[0003] However, it is more difficult to mine thin coal seams under two hard conditions (hard roof and coal seam). Cause damage to support equipment and threats to personnel, making mining more difficult

At present, the problem of comprehensive mechanized mining of two hard and thin coal seams has not been solved well, and the mining effect has not been ideal

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