Cleaner recovery of multiple valuable metals from cyanide tailings via chlorination roasting

Recovery of valuable metals is hindered by sulfur in cyanide tailings. In this work, a process for the clean recovery of multiple valuable metals through chlorination roasting was proposed. HSC software was used to find that the process of dissociation of chlorides is further accelerated by sulfur in the tailings. Experiments were carried out to study temperature variables and chlorinated agent variables. The optimum conditions were identified to be a CaCl₂ dosage of 4%, roasting temperature of 1323 K, achieved maximum recovery of 84% of Au, 71% of Ag, 72% of Cu, 92% of Pb, and 69% of Zn.