Saint-Petersburg State University of Industrial Technologies and Design (Saint-Petersburg, Russia):
Aleksandrov A. V., Head of Chair, Doctor of Engineering Sciences, Professor, IGDALEX@rambler.ru

Mining Institute of the Far Eastern Branch of the RAS (Khabarovsk, Russia):
Bogomyakov R. V., Researcher, roma.bogomyakov@mail.ru
Konareva T. G., Researcher, konar_tat@mail.ru

The mineral resource base of placer and technogenic formations of the Far Eastern Federal District (FEFD) is analyzed. It has been established that the total resource potential of the technogenic formations in the Far Eastern Federal District is estimated at around 4,500 tons. The main losses are associated with fine-grained and encapsulated gold. Against the background of depleting reserves of high-grade ores, ores with complex composition are increasingly used in industrial operations, as well as low-grade and off-balance ores, overburden, mature dumps and other technogenic raw materials. The expediency of using heap leaching for such technogenic formations is substantiated. Kruchininsky deposit is a sufficiently large technogenic formation of the Trans-Baikal Territory. It is a complex development project as it is characterized by the filament-focal structure of the productive strata and low seam thickness at relatively large depths. Native gold particles are mostly fine, dusty, and lamellar in shape. Comparative studies of percolation leaching of gold have been carried out under the three process flows: using a standard cyanide solution; using a cyanide or chloride solution with preliminary holding of the sub-sample for three days in an electro-photo-activated carbonate-peroxide solution. The analysis of the results allows selecting the chloride solution option as the best possible process flow.
The work was carried out with the financial support of the Russian Science Foundation (project No. 19-17-00096).

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