“Polyus” JSC, Krasnoyarsk, Russia

S. V. Drozdov, Head of the Laboratory of Hydrometallurgical Processes, e-mail: DrozdovSV@krs.polus.gld
I. A. Proskuryakova, Leading Engineer of the Laboratory of Hydrometallurgical Processes
A. I. Tychenko, Technologist of Hydrometallurgical Department

Syberian Federal University, Krasnoyarsk, Russia

N. V. Belousova, Head of the Chair of Metallurgy of Nonferrous and Rare Metals

Nowadays in world practice it is used such types of equipment as “Gekko InLine Leach Reactor” and “Acacia” reactor for intensive cyanidation of gold-bearing gravity concentrates. Producers of “Acacia” Reactor recommend using special organic addition Leachaid, which is also called “leaching accelerator”. It works as an oxidizer for gold and other components that present in the concentrate. Some disadvantages of using Leachaid were revealed, such as strict dosage necessity, too long time of gold recovery, complication of concentrates treatment, which contain high sulfide quantity and iron scrap, increasing electrolysis time because of formation in pregnant solutions products of Leachaid decomposition and in the end its high price. The opportunity of substitute oxidizer Leachaid, which is used in intensive cyanidation process of gold-bearing concentrates in “Acacia” reactor, on more effective oxygen was investigated. Laboratorial experiments on the apparatus, which completely simulates “Acacia” Reactor technology, were made. Subsequently investigations were removed in industrial conditions with adjustment of technological characteristics of intensive cyanidation process. For the reason of laboratorial investigations results it was established that substitute of organic reagent Leachaid on gaseous oxygen allowed to increase gold recovery from concentrate from 75–87 to 95–98% and to reduce time of intensive cyanidation more than twice. Also it makes it possible to significantly raise the electrolysis productivity. Industrial trials on “Acacia” Reactor completely confirmed results of laboratorial experiments that were received earlier. In the issue of good results of laboratorial and industrial tests employment of high-pressure oxygen instead of Leachaid in intensive cyanidation process was implemented at one of the factories of “PolyusGold” company.

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