Grate Coal Mine Pillar Sublevel Caving Ore Control Study

Caving with pillars has been widely in the world, and with the developing of mining technology and the increasing of mining depth, the proportion of using it is getting increase, Ore-drawing control is the difficult core problem of caving with pillars. It is the goal of mining engineers to study ore-drawing theory and take it into directing discharging operation so effectively that the dilution and the ore loss can be lowed and the recovery of resources can be increased as much as possible.Bizigou copper orebody has a inclination of 40°nd a thickness of 30m in average. Orebody shape is complex. Upper part of orebody shape is quite steep, deep part of it is quite slow, the tow sides of it has a lot of branch. Orebody shape has many faults, joint development, broken wall rock, bad stability. For many years, caving with pillars is used to exploit ores, with its loss rate ranging 35% and dilution 36%, so ores is in the range of high dilution and high loss.Aim at ore-drawing control of Bizigou copper ore caving with pillars. Firstly, this paper used experimental studies of physical simulation(similarity ratio 1:30), conclusion that on the premise sublevel height 15m of Bizigou copper ore caving with pillars, the best funnel distance is 6m X 6m; based on Volume continuum equation stochastic theory of ore-drawing, according to simulation of ore-drawing, theoretical relationship on the basis of quality of drawn and height of ore-drawing, and drawn-body testing, conclusion that granular media flow parameter of Bizigou copper ore is n0=0.6646,&=0.3121 and funnel distance of ore-drawing is 6m-6.3m by formula L=2(?)+S. Through a comprehensive analysis of the study. on the premise sublevel height 15m, appropriate funnel distance of Bizigou copper ore-drawing is 6m X 6m. then analyse relationship between the distribution of granular media flow speed in the discharging opening and height of ore-drawing, layout mode of the traditional funnel is used to optimize, lapsed discharging opening outward, the distance is about 0.4m, so it can be good effects of ore-drawing by appropriate management of ore-drawing. Finally, optimization of ore-drawing mode has been successfully in Bizigou copper ore by industrial test, recovery rate is 73.48% and dilution is 26.61% by orebody of industrial test, compared with index in past years in Bizigou copper ore, it has been very great improving.At present, Caving with pillars is successed in underground mine of our country, which has very extensive application now and in the future. The results of this research can be applied to similar mines...