St. Petersburg Mining University (St. Petersburg, Russia):
Boduen A. Ya., Associate Professor, Candidate of Engineering Sciences, bodyen-anna@mail.ru
Fokina S. B., Assistant, Candidate of Engineering Sciences, fokina_sb@spmi.ru
Petrov G. V., Professor, Doctor of Engineering Sciences, petroff@spmi.ru

Peter the Great St. Petersburg Polytechnic University (St. Petersburg, Russia):
Andreev Yu. V., Associate Professor, Candidate of Engineering Sciences

Hydrometallurgical processing of tailings of enrichment of cupriferous sandstone will increase extraction of copper in technology and reduce the burden on the environment. The tailings sample of copper sandstones, which contained 5.14 % Cu, 83.9 g/t Ag and 3.5 g/t Re, was used for research. The mechanism and kinetic characteristics of the ammonia autoclave leaching of copper-containing tailings in the temperature range of 120 ÷ 180 °C and oxygen pressure of 0.2 ÷ 0.8 MPa are revealed. The parameters of the one-stage process are established, which allow to achieve the most complete extraction of copper, silver and rhenium into the solution. A technology has been developed for the hydrometallurgical processing of cupriferous sandstone enrichment tailings, which includes autoclave ammonia leaching and thermal decomposition of ammonia and allows to obtain commercial copper concentrate and regenerates ammonia.

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