Study on the influence mechanism of gangue mixing rate and top coal recovery rate under different lumpiness conditions

School of Energy and Mining Engineering, China University of Mining and Technology-Beijing, China

^* 1373010992@qq.com

Abstract

In this paper, for the S5207 working face of the 3# coal seam of Yuwu Coal Industry, numerical calculations are used to simulate the initial coal discharge process under different top coal lumpiness conditions, and the variation law of top coal recovery rate and gangue mixing rate, the optimal mixing rate, the morphological characteristics of the top coal discharge body and the coal-rock interface are studied. The results show that the smaller the top coal lump, the higher the recovery rate of top coal, and the increase of the gangue mixing rate and the recovery rate of the top coal increase, which increases faster in the range of 3%-9% of the gangue mixing rate. The analysis determines the optimal mixing rate under different lumpiness conditions. The smaller the lumpiness, the more round the discharge body is, and the larger the volume. In the middle and late stages of coal discharge, with the increase of the mixing rate, the development degree of the discharge body level increased. There are two continuous curves of curvature at the interface of coal and rock, and the lump degree and gangue mixing rate are the main controlling factors affecting its morphology and slope. This study provides theoretical guidance for the actual intelligent fully integrated mining.