Irkutsk National Research Technical University (Irkutsk, Russia):

Burdonov A. E., Associate Professor, Candidate of Engineering Sciences, slimbul@inbox.ru

«Svetloye» LLC (Irkutsk, Russia):
Kovalev E. V., Process Engineer

Mining Institute of the Far Eastern Branch of the Russian Academy of Sciences (Khabarovsk, Russia):
Prokhorov K. V., Leading Researcher, Candidate of Engineering Sciences
Rasskazova A. V., Leading Researcher, Candidate of Engineering Sciences

The study covers pelletization of argillaceous gold-bearing ores from one of the deposits in the Russian Federation, as represented by three ore shoots having commercial gold concentrations. Mining of the first and second shoots has been completed; further operations at the deposit will be focused on the argillaceous ores of the third open pit, having low filtration properties. The sample analyzed refers to the oxidized and mixed types of ores and is represented by secondary quartzites, monoquartzites, mudstones, and slightly altered rocks. The rocks are limonitized; the mass fraction of sulfides, oxidized to varying degrees, is 1–3 %. The gold content is 17.3 g/t and the silver content is 7.5 g/t, as established by atomic absorption analysis. Pelletization was carried out under laboratory conditions in a batch drum agglomerator. The optimal process conditions were identified. A compression/filtration unit was developed for the ore percolation leaching experiment. Irrigation was carried out using alkaline solutions of sodium cyanide and peristaltic pumps. It was found that, during leaching, samples with the grain size of 20 and 10 mm demonstrated ore siltation, with the cyanide solution present on the surface. During the experiment using pelletized ore, no siltation or surface puddle formation was observed. Grinding to a fineness of –10 mm allowed additionally recovering 3 % of the metal, which indicates the presence of finely dispersed gold and the need for finer grinding. The recovery indicator for the pelletized sample was 12 % higher than in the basic experiment (at the fineness of –20 mm).
The work was supported by the grant from the President of the Russian Federation No. MK-1739.2020.

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