Zijin （ Changsha） Engineering Technology Co,Ltd,Chagnsha
The pillars stability after filling the goafs was simulated，and the results show that the stability have been significantly improved. Firstly，tailings in the old tailings reservoir were mined by excavator，pulped，pumped to the plant and then entered the regrinding process together with the crushed and grinded ores to re-concentate. Then，the existing filling systems was optimized and retrofited by adding the deep cone thickening system and the concrete towing pump for improving the utilization rate of tailings and increasing the filling distance respectively，the full tailings were conveyed to the deep cone thickener，which were then made into the cemented full tailings slurry to fill the goafs of Cai 1# mining area. The top and bottom pillars were mined by ring medium-deep blasthole，the middle pillars were mined by deep blasthole with a cut-raise as blasting space，and the remote scraper was used for ore carrying. The mining rate of pillars was 70% ~80%. Comprehensive utilization of residual mineral resources has achieved remarkable economic benefits.