Influence of dimension of rectangular ore drawing hole withmulti-sublevel and multi-way on ore drawing effect

Aiming at the problems of high rock mixed rate and large ore loss in sublevel caving without sill pillar, the drawing experiments under different height and width of ore-drawing hole are carried out by using the similar model of multi-sublevel and multi-path.From the angle of influencing factors of granules fluidity and formation and destruction of granules pressure balance arch, the variation laws of ore recovery and rock mixed rate are analyzed.The results show that when all mining approach of the same sublevel are mined at the same time, properly enlarging the width or reducing the height of the ore-drawing hole could increase the ore moving bandwidth, improve the ore fluidity, increase the ore recovery and reduce the rock mixed rate, and the ore recovery rate of each sublevel is also significantly increased.