Feasibility Study on Co-processing Cyanide-contained Gold Mine Tails in Cement Kiln for Resource Utilization

The test of co-processing cyanide-contained gold mine tails in cement kiln for resource utilization was carried out. The feasibility of cement raw material replaced partially by cyanide-contained gold mine tails was discussed, and the removal effect of cyanide in treated mine tails and exhausted gas was investigated. The experimentation indicated that it was feasible to partially replace cement raw materials by cyanide-contained gold mine tails. The oxygen concentrations in the kiln effected cyanide removals in mine tails slightly, while the treatment temperature played an import role with high temperature able to promote cyanide removal in mine tails. The cyanide content in the treated mine tails agreed with Standard of Soil Quality Assessment for Exhibition Sites (HJ 350-2007). The oxygen concentration had some effect on the removal of cyanides in the exhaust gas; the cyanides concentration in the exhaust gas was low when with high oxygen concentration, basically not affected by the treatment temperature. The cyanide decomposing rates were above 98% as a whole and the cyanide concentrations in exhausted gases during cement kiln co-processing gold mine tails satisfied Integrated Emission Standard of Air Pollutants (GB 16297-1996) and Occupational Exposure Limits for Hazardous Agents in the Workplace (GBZ 2.1-2007).