Metallurgical byproducts application aimed at improving ore concentration efficiency at Talnakh Concentrator

Abstract

Talnakh Concentrator processes the mixture of high-grade and cupriferous ores to produce copper and nickel-pyrrhotite concentrates via the process implemented in 2016. Since 2018, pursuing a comprehensive use of raw materials, Talnakh Concentrator proceeded with reconcentration of low-nickel pyrrhotite product to produce low-grade reflotation concentrate (0.8–1.2% of nickel) sent to Nadezhda Metallurgical Plant named after B.I. Kolesnikov (hereinafter, NMP) for hydrometallurgical processing. Testing of Copper Plant’s byproducts application was aimed at increasing nickel recovery as a result of the nickeliferous pyrrhotite surface activation by copper ions. It is impractical to apply blue vitriol, traditionally used for this purpose, as it leads to a significant decrease in technical and economic performance due to an increase in operating costs for reconcentration. The Copper Plant products, such as decopperized electrolyte and a coppernickel solution from PGM Concentrator were tested as activators. These products contain not only residual amount of copper ions, but also a substantial quantity of sulphuric acid. The study showed that Copper Plant’s solution application increased the amount of nickel recovered to the product of reconcentration and improved the product pyrrhotite content that favorably effected its subsequent pressure oxidation leaching. Application of the copper-nickel solution from PGM Concentrator is considered to be the best option due to a higher ratio of copper ions to sulphuric acid. Solutions applied during nickel-pyrrhotite flotation at Talnakh Concentrator were also studied. The authors simulated the initial composition alteration of Talnakh Concentrator’s feed with an increase in a share of cupriferous ore, containing much less pyrrhotite than high-grade ore. It was found out that if the feed contained critical amount of cupriferous ore, application of Copper Plant’s solutions contributed to maintenance of sulphur content in the nickel-pyrrhotite concentrate of Talnakh Concentrator that provided energy potential required for the appropriate thermal conditions of NMP’s smelting vessels.