Fully mechanized caving mining method for extra-thick hard coal lower layer

Abstract

The invention discloses a fully mechanized caving mining method for an extra-thick hard coal lower layer. The method includes the steps that an extra-thick hard coal layer is divided into an upper layer and the lower layer; the lower layer is tunneled after the fully mechanized mining of the upper layer is finished; top coal on the roadway of the lower layer is reserved and the top coal is taken as a fully mechanized mining roof which does not need to be paved with a net; coal is recycled as caving coal after the coal arrives at the back of a frame; fully mechanized caving equipment is mountedin the roadway of the lower layer; a coal mining machine is adopted to cut the coal at the lower part of the lower layer; and the top coal is recycled at the upper part of the lower layer by top coalcaving. According to the fully mechanized caving mining method for the extra-thick hard coal lower layer, the top coal is used as the fully mechanized mining roof, lapping is not needed, and the topcoal is recycled the as caving top coal after arriving at the back of the frame, so that the safety of the roof is ensured, and coal resources are recycled. The method improves the recovery rate of the coal resources, reduces the hidden danger of the spontaneous combustion of goaf, which is better in safety, is high in efficiency, is good in benefit, and provides a new technology, a new method andnew experience for the safe and efficient recovery of the lower layer after the upper layer fully mechanized mining of the extra-thick hard coal.

Description

technical field [0001] The invention relates to the technical field of coal mining, in particular to a fully mechanized caving back mining method for extra-thick hard coal with lower layers. Background technique [0002] The technical status of my country's ultra-thick coal seam mining: [0003] At present, my country generally adopts the following four mining methods for extra-thick coal seams: layered fully mechanized mining, fully mechanized caving mining, large mining height mining and open-pit mining. Among them, roadway excavation and roof control of fully mechanized mining in layered fully mechanized mining are relatively difficult, with high support costs, poor safety, and net laying. The fully mechanized caving mining method requires pre-splitting blasting when the top coal is too thick, there are many large pieces, and the coal recovery rate is poor, and the goaf is prone to spontaneous combustion; the large mining height mining method is currently only 7.2m and 8...

AI Technical Summary

Problems solved by technology

Because the mining of the lower layer is too difficult and the safety is too poor, it has been nearly 10 years since the upper layer was mined and the lower layer has not been mined.

If you continue to mine the lower layers according to the original plan, not only will the 2m thick coal resources (about 10.2 million tons) be wasted, but also a large amount of coal left in the goaf will cause a major hidden danger of spontaneous combustion

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