The efficacy of a new iodination roasting technology to recover gold and silver from refractory gold tailing

Gold tailing is residue waste, but it's also a secondary resource. Thus far, little is known about the iodination roasting and it was first used to dispose gold tailing. Here, we show that iodination roasting can efficient recovery of gold and silver from the refractory gold tailing with higher recovery efficiency than chlorination roasting. Different factors affecting the recovery effectiveness of gold and silver were investigated to obtain the maximum gold and silver recovery efficiencies. We achieved recovery efficiencies of 99.92% and 87.78% for gold and silver by the iodination roasting, and thus can be applied to treat and recover various kinds of gold and silver residues from the solid phase. We also provide roasting principles of the iodination roasting process using experimental design method by changing the contact between Iodine Donor (KI) and gold tailing, and found that Iodine Donor decomposes to iodine gas and the iodine gas reacts with the Au and Ag, which is similar to the reported mechanism of chlorination roasting. Moreover, the behavior results of other elements during iodination roasting confirm that it could selective enrichment of gold and silver from gold tailing. (C) 2020 Elsevier Ltd. All rights reserved.