Experimental study on the application of the insert technology in the mining of medium-thick and steeply inclined orebodies

The sublevel caving method has been widely used in the mines for mining medium-thick and steeply inclined orebodies, but the problem of ore loss and dilution still exists during the mining process and has yet to be fundamentally solved. In order to realize the green mining with the coordination of resources and environment, an insert drawing technology is proposed to address this issue with the medium-thick and steeply inclined orebody as the research object based on the structural principles of the insert within the silo. The influencing factors mainly considered in this paper are the orebody dip angle, thickness, and sublevel height. Eighteen experiments of the insert drawing with the conventional cut-off grade drawing with respect to these three factors were designed to investigated the impacts of these three factors on ore loss and dilution. The experimental results indicate that the ore recovery rate of the insert drawing technology is higher than that of the conventional cut-off grade drawing in mining ore bodies of different thicknesses and dip angles. In conditions of the same mixing rate of the waste rock, the ore recovery rate of the insert drawing technology is 69.09% to 82.9%, which is higher than that of the conventional cut-off grade drawing by 12.66% to 30.88%. Furthermore, the ore recovery ratio increases with the increasing the orebody dip angle when it is between 60° and 85°. On the other hand, the ore recovery rate of the insert drawing technology is higher than that of the conventional cut-off grade drawing in mining ore bodies when the orebody thickness ranges from 6 m to 10 m. Additionally, when it is between 10 m and 14 m, the ore recovery ratio increases with the increasing the sublevel height. Meanwhile, the mechanism of the insert drawing technology is studied. By setting up the insert structure and changing the opening and closing sequence of the clapboard in the quarry, the ore-rock flow path is changed, the ore flow range and flow rate is increased, and the ore-rock contact is controlled, thus ore loss and depletion is reduced. Research demonstrations that the insert drawing technology is superior to the conventional cut-off grade drawing, enrich and improve the issue of ore loss and dilution in an expict manner. This technology provides valuable technical support for mining medium-thick, steeply inclined orebodies.