Comprehensive use of raw materials through optimization of the concentration and metallurgical complex of Norilsk division

Abstract

Using a concentration process introduced in 2016, Talnakh Concentrator produces copper and nickel-pyrrhotite concentrates by processing high-grade and cupriferous ores. Dump tailings comprise rock tailings separated at the early process stage and low-nickel pyrrhotite product obtained at the final concentration stage. The predominant mineral found in the ores processed by Talnakh Concentrator includes pyrrhotite, which in most cases contains nickel. Low-nickel pyrrhotite product contains pyrrhotite that bears maximum Ni 0.4% in the form of impurity. Another feature characterizing the pyrrhotites found in Norilsk is the presence of isomorphic inclusions of platinum group metals. Aimed at a more comprehensive use of raw materials, in 2018 Talnakh Concentrator introduced a process for repreparation of low-nickel pyrrhotite concentrate. A low-grade flotation concentrate is obtained with Ni 0.8÷1.2%, which is then sent to the hydrometallurgical circuit of Nadezhda Metallurgical Plant named after B.I. Kolesnikov (NMP). Being a sulphide, pyrrhotite enhances the autogenic performance of matte smelting process. The nickel concentrate produced by Norilsk Concentrator from disseminated and cupriferous ores is a low-energy material containing 15–17% of sulphur. So the heat generated during its oxidation flash smelting is insufficient to maintain the heat balance of the furnace. The nickel concentrate produced by Norilsk Concentrator is processed mixed with Ni-containing burden, which lowers the total heat balance of the flash smelting furnaces at NMP. In 2021, a process was introduced when a part of the tailings from the low-nickel pyrrhotite concentrate line of Talnakh Concentrator is used to recover high-pyrrhotite concentrate to be added to the nickel concentrate produced by Norilsk Concentrator in order to improve th e latter’s energy performance.