Navoi Mining and Metallurgical Combinat, Navoi, Uzbekistan:

K. S. Sanakulov, Chief Executive Officer, Professor, Doctor of Engineering Sciences, info@ngmk.uz
M. M. Ismagilov, Deputy Chief Engineer

Irgiredmet, Irkutsk, Russia:
V. E. Dementiev, Chief Executive Officer, Candidate of Engineering Sciences
V. M. Mullov, Leading Researcher, Candidate of Engineering Sciences

One of the trends in efficient subsoil management is processing of low-grade gold-bearing materials (uneconomic ore reserves) by heap leaching. Tailings after the process yet contain considerable metal. This situation is typical of the Navoi Mining and Metallurgical Combinat, Republic of Uzbekistan – a leading gold and uranium producer in the country. For 20 years of operation, the gold heap leaching shopfloor has accumulated 217 Mt of tailings with the residual gold content of 0.7 g/t. In connection with the deficient supply of natural raw materials for operating Hydrometallurgical Works 2, the question of re-treatment of heap leaching tailings to reextract gold came up. In such a way, the tailings pond became a man-made deposit. The scientifi c analysis of the problem and development of economically efficient processing technology for the tailings was charged to the Irgiredmet Institute, Russia – an internationally recognized leader in the field of integrated mineral processing and a business partner of Navoi MMC. The Irgiredmet’s experts together with the fellows of the Central Research Laboratory of Navoi MMC accomplished a series of lab-scale and full-scale research into dressability of heap leaching tailings. As a result, the production procedures were elaborated for the construction of a dedicated plant for processing of tailings and the related technology was proposed. The technology passed commercial trial: gold yield from the tailings reached 65%.

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