LLC “Institute “Gipronikel”, Saint Petersburg, Russia:

P. M. Saltykov, Senior Researcher, e-mail: PMSal@nikel.spb.su
M. I. Kalashnikova, Head of Hydrometallurgy Laboratory
E. G. Saltykova, Leading Engineer

Hydrometallurgical method for processing of precious metals containing ore pyrrhotite-pentlandite concentrates was developed for ensuring of high rate of platinum metals recovery into the value products, regardless of the metals’ head grade, i.e. within the range of 2–30 g/t. Platinum metal losses, occurring in the course of pyrrhotite-pentlandite concentrates’ hydrometallurgical processing are formed at leaching stage. Natrojarosite is a crystalline matter with less developed surface, compared to other ferrous phase. According to this, the natrojarosite slurry hydrate phase formation leads to the decreased sorption activity of ferrous portion and to the decreased passivation rate of undecomposed sulfide minerals by ferrous hydrate particles. As a result, platinum metals are lost to tails at cake flotation, produced during pyrrhotite-pentlandite concentrates leaching. Low-temperature autoclave oxidative leaching of finely ground concentrate is upstream circuit. Autoclave oxidative leaching runs at 100 ^оС and at 0.5 MPa oxygen partial pressure for 1.8–1.9 hours. With the aim of platinum metal losses decrease, sulfuric acid and sodium sulfate are added to the process, ensuring natrojarosite formation.

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