PRODUCTION OF HIGH-GRADE FERRONICKEL FROM LOW-GRADE OXIDE NICKEL ORES

摘要

Production of commercial-grade nickel-containing products, and in particular ferronickel with a nickel content of at least 20% from low-grade oxide ores is a very important issue for Russia, because Russia has immense reserves of oxide nickel ores with nickel contents of less than 1.2%. In practice, the process of electric smelting with slags containing over 13% FeO inevitably results in uncontrolled frothing of the melt and its spillage from the furnace. A method has been developed in the Gintsvetmet Institute for production of high-grade ferronickel by oxidizing low-grade ferronickel with ore in an electric furnace; the gas emission and frothing are eliminated due to a low carbon content of the melt in this process A flow diagram has been proposed with two parallel streams of ore treated in continuous mode in two electric smelting furnaces. To verify the proposed flowsheet, laboratory tests have been carried out, which have demonstrated the feasibility of production of commercial-grade ferronickel with a content of 26.6% Ni and 1.83% Co from ores containing 1.08-1.1% Ni, 0.08-0.12% Co and up to 30.7% Fe. This technology is now in the process of preparation for commercial introduction at the Buruktalsky nickel smelter (South Urals, Russia).