OBTAINING COOPER SULFIDE AND BETTER QUALITY MIXED SULFIDE NI + CO

Abstract

The document contains the results of a pilot test on copper separation in the form of copper sulfide prior to the precipitation of Ni+Co mixed sulfides using ammonia hydrosulfide as a precipitation reagent. The investigation was conducted at the nickel and cobalt Mini-Refinery belonging to the Nickel Research Center. The selected test design was 32 plus 2 repetitions for a total of 27 test runs. The Statgraphics software (version 5.1) was used to assist on the investigation. Temperature and
consumption of precipitation reagent were considered as independent variables. The resulting copper precipitation efficiency was above 98% while cobalt and nickel precipitation
efficiencies were below 14 % and 2 % respectively. These results were achieved at 313K and 5-6 stoichiometric of precipitation reagent. The copper content of the product solids was 14-21%,
which makes this product marketable, while nickel content remained below 17%. Mathematical statistical models describing precipitation efficiency trends for copper, cobalt and nickel were generated. Mixed sulfides precipitation was carried out at 313 K and precipitation reagent consumption requirements (stoichiometric) tripled. The quality of the resulting product was better (0,13 % copper) which favors marketing and refining.