中國(guó)有色金屬學(xué)報(bào)(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 32 No. 12 December 2022 |
（1. Key Laboratory for Ecological Metallurgy of Multimetallic Mineral (Ministry of Education), Northeastern University, Shenyang 110819, China;
2. School of Metallurgy, Northeastern University, Shenyang 110819, China）
Abstract:Because of the highly toxic cyanide in the gold cyanide residues, cyanide must be removed for environmental protection. The process mineralogy of residues was studied firstly, and then cyanide removal was carried out by three chemical methods. The results showed that the residue mainly contained Si, S and Fe. Pyrite was the main metallic mineral, and the iron-complex cyanides make cyanide removal difficult. The minerals in residues were in ultrafine particle size with high monomer dissociation degrees. In H2O2 oxidation process, the self-decomposition and side reactions resulted in high consumption of H2O2. In Na2S2O5-air oxidation process, the time for complete process was long because of the reactions between Na2S2O5 and O2. Na2SO3 oxidation method was found to be a new method for cyanide removal without air inflation device. The cyanide content was reduced to the national standard level in 90 min at pH 9.0 with optimum Na2SO3 dose of 2.0 g/L.
Key words: gold cyanide residues; process mineralogy; cyanide removal; H2O2 oxidation; Na2SO3 oxidation
