Research of New Filling and Mining Technology Using Waste Rocks in Steep Coal Seams

Abstract

During the extraction of steeply inclined coal seams, the coal recovery ratio is low be-cause of the coal pillar loss and the production of waste rock is high due to lots of rock roadways which causes serious environmental pollution. This status is conflicted with the strategy of Clean Coal Mining and Green Coal Mining in China, so it is necessary to develop new coal mining method. In this paper, Downward Stratified Gangue Self-filling Method on the Flexible Shield (DSGSMFS) is put forward first. It means that the coal face is lain horizontally and advances along the dip; the flexible shield is used to separate the gob area; the waste rocks are self-filled downward to the top the shield; the coal is broken by drilling and blasting method under the shield, and the broken coal is transported by the electrical winch and the scraping mucker; the flexible shield moves downward automatically by the weight of itself and waste rocks. Field test shows that the strata displacement is effectively controlled by using DSGSMFS, so some coal pillars are recovered; as a result the problem of large quantity gangue and low coal recovery ratio in steep coal seam is solved. DSGSMFS is proved to be a new hopeful and effective coal green mining method.