| abstract |
Ores containing copper, zinc, silver in the form of sulfides are treated by a solution of sulfurated sulfite ions and ammonium ions in order to remove most of the metals from the sulfide ores. This treatment renders the resulting gold bearing ores much more amenable to cyanide extraction. Dissolved metals are reclaimed by appropriate techniques, such as electrowinning or liquid-liquid extraction, and the solution of sulfurated sulfites and ammonia is recycled for further lixiviation of fresh ores. |