Joint Enterprise of Scientific and Production Association “RIVS”, Saint Petersburg, Russia.

A. Ya. Boduen, assistant professor of a Chair of Metallurgy, e-mail: A_Boduen@rivs.ru
B. S. Ivanov, Industrial Engineer of a Department of Hydrometallurgy

Saint Petersburg Mining University, Saint Petersburg, Russia:
G. V. Petrov, Professor of a Chair of Metallurgy, e-mail: petroffg@yandex.ru
M. A. Serebryakov, Post-Graduate Student of a Chair of Metallurgy

Nowadays, copper industry consists mostly of pyrometallurgical technologies (not more than 10–15% of hydrometallurgy are included). Exhaustion of rich copper deposits led to the necessity of expansion of raw material base due to the involvement of poor and off-balance ores in production, which, in turn, led to obtaining of ill-conditioned concentrates, unsuitable for profitable use in pyrometallurgy. This paper shows the investigations of autoclave oxidation ammonia leaching of ill-conditioned copper concentrate (Jezkazgan deposit). Copper, silver and rhenium are the marketable metals in concentrate. Autoclave leaching parameters, allowing the selective transfer of all marketable metals in solution relating to iron and waste rock components, were experimentally defined during one technological operation. Usage of ammonia leaching as a main operation allows the following operations:
• development of rational technology of extraction of valuable components from ill-conditioned copper concentrate with their obtaining as marketable products;
• regeneration of the basic reagent (ammonia);
• ammonia sulfate obtaining as an additional marketable product.
Ammonia solutions are less aggressive than acid solutions, which allows the use for mechanization of cheaper engineering materials. The production waste is autoclave cake, which, according to its composition, has actually no difference from the concentration tailings, has no acid reaction and can be stored in tailing dump of concentration plant.

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