Sustainable Mining and Metallurgy

The leachate of the residue from filtration of cyanidation tailings contains high concentration of total cyanide and can’t meet the requirement of relevant technical specification. Therefore, the NaHSO₃-air method is proposed for treating cyanidation tailings. In this paper, the optimal reaction conditions of the NaHSO₃-air method were studied based on test. The study showed that the best cyanide removal effect occurs under such conditions as NaHSO₃ dosage 6.00kg/t, initial pH value 9.5, CuSO₄·5H₂O dosage 300mg/L, no aeration, reaction lasting 2h and reaction temperature at 19℃. After 13 times of closed-circuit circulation under the optimal reaction conditions, the total cyanide in the toxic leachate was less than 5mg/L, meeting the cyanidation tailings treatment standard of TSF in the technical specification.