Smelting of Fe-Si-Mn-Al Complex Alloy Using High-Ash Coal

Results of studies for preparing complex Fe-Si-Mn-Al master alloy are presented. High-silicon lean manganese ores of the West Kamys ore deposit (18-30% Mn and 35-45% SiO2) and high-ash coal of the Saryadyr deposit (Kazakhstan) with an ash content of 45-55% are used as charge materials. Technological studies are conducted in an ore-thermal electric furnace with a capacity of 250 kVA. An experimental batch of master alloy with an average chemical composition is obtained, %: Mn - 20; Si - 42; Al - 16; P - 0.03; Fe balance. Dependences of aluminum, silicon and manganese content in final alloy on ratios Mnox + Feox + SiO2 + Al2O3)/Cso and Mnox/(Mnox + Feox + SiO2 + Al2O3) in an initial charge are revealed. The fundamental possibility and expediency of obtaining an aluminum silicon manganese master alloy of a new composition by a slag-free method with integrated use of all useful components of lean manganese ore and high-ash coal is demonstrated. An X-ray diffraction pattern of prototypes indicates that alloy phase composition is presented in the form of intermetallics - MnSi, Mn15Si26, Al2Fe3Si4, Al5Fe2, FeSi, and structurally free silicon. The resulting master alloys of selected composition are not subject to self-dispersal reactions.