The Experimental Study On Loss And Dilution Of Diversion Drawing Of Inclined Medium-thick Ore Body

The problem of ore loss and dilution is serious in the mining of inclined medium-thick ore body by non-pillar sublevel caving method.Based on the technology of diversion drawing by non-pillar sublevel caving method,this paper improves the diversion structure,and carries out the improved physical simulation experiment of diversion drawing and the comparison experiment of conventional ore drawing.On the basis of experiment,the mechanism of loss and dilution of improved diversion drawing technology was studied.The main conclusions are as follows:(1)Based on the diversion drawing by non-pillar sublevel caving method,the improvement study of diversion drawing technology was carried out.The improved diversion structure changes the contact form between the ore and overburden,and makes the ore release priority while changing the moving track of waste rock and slowing down the mixing of waste rock.(2)Experimental improved diversion drawing experiment and comparison experiment of conventional ore drawing,the ore body thickness is 4~10m,and the ore body dip Angle is 45~55°.The resultsshow that,compared with the conventional ore drawing experiments,the recovery rate of ore with the new diversion drawing technology is increased by 4.37~19.26%,and the dilution rate is reduced by3.12~25.52%,which verifies the feasibility of reducing ore loss and dilution with the new technology.(3)loss mechanism: with the increase of ore drawing amount,the waste rock slope formed after the waste rock reaches the ore drawing mouth hinders the flow of footwall ore and forms strip-like footwall wall residue;The triangular residues are mainly related to the side hole Angle and the natural resting Angle.The waste rock and ore mixed and moved,and a small amount of ore remained at the end of ore drawing.(4)dilution mechanism: due to the limitation of upper and lower wall and end boundary,overburden waste rock moves downward through the diversion opening to the section stope.When the waste rock extends to the ore drawing opening at the top of the dropping funnel,the waste rock funnel breaks and the top and side waste rock begins to mix with the ore,resulting in ore dilution.