Industrial application of ammonia-assisted cyanide leaching for copper-gold ores

A description of the agitation leach plant used for treating gold-copper ores at Anglo Asian Mining's Gedabek mine in Azerbaijan is given. The plant employs a unique resin-in-pulp system for gold recovery. The integration of the agitation leach plant into the existing heap leach/ADR/SART operation is described. Operational problems caused by increasing amounts of copper in the Gedabek gold ores are outlined. Previous work on the use of ammonia in copper-gold cyanide leach systems is reviewed. The test work leading to the introduction of ammonia in the industrial leaching plant is described. In the plant it was found that the extraction of copper was halved by the use of ammonia, thus leading to significant reductions in the amount of cyanide consumed in the full-scale leaching system.