Green Treatment of Cyanide Tailings Using a “Filter Press BackWash–Chemical Precipitation–Gaseous Membrane Absorption” Method

Based on a “filter press backwash–chemical precipitation–gaseous membrane absorption” process, treatment of harmless cyanide tailings was conducted using from gold smelting enterprises (Yunnan Province, China) as the research object. The effects air-drying time, backwash water parameters, initial pH acidification, NaHS dosage, cyanide-containing flow rate, and gaseous stages process were investigated. Chemical composition, X-ray diffraction, photoelectron spectroscopy analyses copper products carried out. Results showed that content in product 54.56%, chemical composition mainly CuSCN, CuS, Cu2S, CaSO4. Five cycles experiments out under optimal conditions; results can make treated meet requirements technical specification for pollution control leaching residue industry (TSPC) standard storage pond have certain stability. average recovery rate total elution 97.8% 99.89%, respectively, removal thiocyanate 94.09%.