PRODUCTION OF SILICOMANGANESE ALLOY FROM EGYPTIAN LOW GRADE MANGANESE ORES

Abstract

In the last years, it has become a great necessary to develop a new technology for utilizing the unused huge amounts of low grade manganese ores with Mn/Fe ratio equals 0.6-1 in the production of silicomanganese due to the gradual depletion of high grade manganese ores reserves. This target can be achieved through a double smelting process in submerged arc furnace. The first process is a carbo-thermic reduction of low grade manganese ore in presence of coke and quartzite to produce low manganese pig iron (2-3% Mn by weight) and high manganese slag with high Mn/Fe ratio reaching about 9 which is suitable after that in the production of silicomanganese. The second smelting process is a carbo-thermic reduction of the produced manganese rich slag in presence of medium grade manganese ore, quartzite, coke and dolomite for production of standard silicomanganese (Si16Mn63 and Si17Mn65). The parameters affecting on the reduction of low grade manganese ore which are power, reducing agent and charge basicity were investigated. The parameters affecting the production process of silicomanganese, namely, the reducing agent, charge basicity and Mn/Si ratio were also investigated. Finally, the optimum conditions obtained for the two processes were applied on a 0.1 MVA pilot scale submerged arc furnace.