Extraction Technology and Pillar Design Analysis of End-Wall Mining System in China
Haoshuai Wu1,Peng Wu2,Yanlong Chen3
Citation :Haoshuai Wu,Peng Wu,Yanlong Chen, Extraction Technology and Pillar Design Analysis of End-Wall Mining System in China International Journal of Mining Science 2017,3(4) : 1-9
A great deal of coal will be left under the final end-walls in Chinese open pit mines because of lower slope angle in shovel-truck mining technology system and larger mining depth. In traditional surface mining system, the coal under the end-walls will be buried by the inner dumping site, and coal resources are normally discarded. Considering these situations, this paper describes end-wall mining system to recover the residual coal based on the geological conditions of coal seams at Chinese open pit coal mines. The mining system can improve economic benefits by exploiting haulage and ventilation roadways from the exposed position of coal seams, and utilizing the existing transportation systems. In order to investigate the pillar design methodology in end-wall mining system, several empirical formulas and methods were discussed based on the actual geological mechanics properties of coal and rock in Chinese open pit mine. The outcome shows that the coal pillar width calculated by Salamon formula may serve as an important reference for pillar design in end-wall mining system According to the theoretical and numerical simulation results, endwall mining system can increase the coal recovery from residual coal resources around end-wall and reduce the effect of underground mining operation on slope stability.