Optimization of mining method for stage open-stoping with backfill of inclined medium-thick orebody

Abstract

The open field subsequent filling method in segmented drilling stage is an efficient mining method for inclined medium thick ore bodies.However, blasting, filling and stope stability show complex relationships, causing surface subsidence, roof and floor collapse, and high mining loss rate.This study adopts engineering analogy and industrial experiments to optimize the process of the sublevel drilling and stage open-stoping with backfill of inclined medium thick ore bodies in the aspects of mining sequence, cutting method, and bottom structure layout, and propose a layout method without leaving pillars in the stope.This method directly connects the side walls of the filling body to the chamber after one-step of filling, and improves the strength of the filling body and the recovery rate of the ore block through extrusion blasting.As the key to this method lies in the implementation time, numerical simulation using ANSYS/LS-DYNA shows that medium-depth hole extrusion blasting is used to form cutting grooves, it should be carried out between 7~9 d after filling and curing of the filling body in the stope.Engineering practice has proved the feasibility of this method, which provides technical support for mining production.

Keywords

• tilted medium-thick ore body
• open field subsequent filling method in segmented drilling stage
• cutting groove
• bottom structure
• ansys/ls-dyna