MMC Norilsk Nickel’s Polar Division, Norilsk, Russia:

A. A. Efimov, Director of the Engineering Support Centre, e-mail: EfimovAA@nornik.ru
O. V. Bolshakova, Head of the Laboratory at the Engineering Support Centre, e-mail: BolshakovaOV@nornik.ru
M. V. Glibovets, Chief Engineer at the Talnakh Concentrator, e-mail: Glibovetsmv@nornik.ru
D. O. Midyukov, Principal Specialist at the Science and Technology Directorate, e-mail: MidyukovDO@nornik.ru

Copper concentrate filtration station constitutes an initial stage in the production circuit of the Copper Plant, and maintaining the required throughput is crucial. Concentrate slurries from Talnakh and Norilsk Concentrators go to the filtration station, where industrial slurry products are also introduced in the production cycle. The filtration station is responsible for two key processes – thickening and filtering. Incoming slurry goes through two consecutive stages of thickening and the thickened product is then filtered. Due to increased performance targets, ceramic filters experience higher loads. Because of it, the established wash modes fail to maintain the necessary permeability of the filter membranes. Brown deposit can be regularly found on the ceramic filtering elements that significantly affects their permeability leading to emergency change-outs. In the course of the study, researchers found what causes the brown deposit on the surface of filter plates and how it forms. A study was conducted that looked at the applicability of reagents for the regeneration of filtering elements. Application of sulphuric acid was found to be the optimum solution. Further studies helped determine the concentration of sulphuric acid solution necessary to remove the deposit. Thus, it is proposed to use decopperized electrolyte from the copper electrowinning plant for filter plate regeneration. The best technical solution was also found. Thus, it is reasonable to use a separate wash tank to take a filter apart before removing the deposit. The industrial tests conducted demonstrated that the regeneration efficiency of the proposed process can be as high as 97%.
Other contributors to this research include A. V. Egorov, V. V. Velichko and O. Yu. Kokoev.

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