Experimental Determination of the Main Parameters of the Refining Process of Rough Ferronickel, Obtained by Iron-Chromium-Nickel Selective Reduction

Abstract

For the development of nickel production in Russia, it is proposed to involve in processing complex natural-alloyed iron-chromium-nickel ores of the Khalilovskoye deposit, which are currently not used due to their poverty, both in iron and nickel. The rough ferronickel obtained by selective carbothermal reduction under laboratory conditions needs dephosphorization (the phosphorus content in the metal can reach 0.7%). In the frame of this work, the dependences of the phosphorus distribution coefficient on the slag basicity and the temperature of the metal were obtained in the course of experiment. Intervals of melting temperatures for calcareous-ferruginous slags were determined experimentally as well. On the basis of the obtained results, the criteria for the selection of the slag mode during dephosphorization of rough ferronickel were formulated: it is necessary to form a slag containing at least 40% CaO and 20% FeO with a basicity of 3.0 ... 3.5; the slag temperature should remain at the level of 1550 ... 1600 ° C, the slag at this temperature has a low viscosity; it is important to create a more complete mixing of the metal and slag for improvement of dephosphorization (by blowing metal with an inert gas or steam).