CHANGCHUN GOLD RESEARCH INSTITUTE

Study on recovery of residual ore and treatment of mined-out areas

This project is based on the mineral resources distribution conditions of Liaoning Jinfeng Gold Mining Company and for the purpose of full utilization of the limited mineral resources and extension of the mine life, where recovery of the residual ores and treatment of mined-out areas were studied through improvement of stoping process and re-delineation of the stope. While referring foreign experiences, independent technologies were also developed, achieving the goals of comprehensive utilization of the mine’s mineral resources and enhancing the mine’s overall performance.
Effective technologies and measures for ground pressure control were taken which maintained the stability of the stope roof, reduced mixed waste rock and secondary dilution, dramatically increased recovery rate of the residual ores, and brought significant economic and social benefits for the mine. Compared with previous mining method, the achieved techno-economical evaluation was substantially improved with the stoping output being more than doubled, the dilution being 10%, 50% lower compared with previous method, and the recovery of the residual ore reaching at 79.3%, an increase of 32.2%. While due to the cost increase in shotcreting, waste backfilling, and local caving, the direct mining operation cost increased by 8.37%, 11,756,300 of profit was added by application of the new stoping method, equivalent to an increase of 64.55 per ton of ore.This project was awarded the second prize for science and technology development by China Gold Association in 2007.