SELECTION OF OPTIMAL CYANIDE LEACHING MODES FOR GOLD FROM ORE DEPOSITS IN THE REPUBLIC OF KAZAKHSTAN

The processing of gold-copper ores with high copper and gold content embedded in sulfide minerals using cyanide solutions is associated with a number of difficulties. Copper, when reacting with cyanide, causes its increased consumption, and the embedding of gold in sulfide minerals causes gold losses with tailings. Therefore, selecting the optimal leaching conditions is necessary for the rational use of reagents, which leads to a reduction in the cost of hydrometallurgical processes for cyanide leaching of gold-copper ores and a reduction in environmental risks. The paper investigates the possibility of processing gold-copper ore with a high copper content and gold incorporated into sulfide minerals (pyrite, chalcopyrite). The aim of the work is to establish the optimal parameters for cyanide leaching by conducting tests in bottle agitators. As a result of the experiments, it was found that as the degree of ore grinding increases, gold extraction increases and cyanide consumption decreases slightly. The addition of coal during leaching significantly increases gold recovery, up to 7 %. It was noted that high sodium cyanide consumption cannot be reduced without a significant decrease in gold recovery. Au ≈ 20 % reduction in sodium cyanide consumption also reduces gold recovery by ≈ 20 %. A laboratory-industrial experiment showed that after 16 hours of ore leaching, 85.8% of the gold is transferred into solution, and after 18 hours, 86.7 %. Further prolongation of the process does not increase the gold recovery rate. Keywords: gold-copper ore, optimal parameters, cyanide leaching, gold, copper.