Silicomanganese production from manganese rich slag

Abstract

Manganese rich slag produced by the appropriate treatment of high manganese pig iron has a high manganese content and results in low fines, is low cost and gives low excess oxygen. Manganese recovery from this slag in the form of manganese ferroalloys compensates for the excess cost of the treatment process. Manganese rich slags produced from the injection of high manganese pig iron under at optimum conditions have levels of (Mn)>35 wt-%, (Mn)/(Fe)>7.65, (Mn)/(Si)>2 and (Mn)/(P)>285, which satisfy requirements for use as raw material in silicomanganese alloy production. Various experiments were carried out to smelt high manganese slag resulting from the treatment of high manganese pig iron to produce silicomanganese in a bench scale submerged electric arc furnace. Use of such manganese rich slag in the proportion of 40% of the blend has been found to be optimum to obtain a silicomanganese alloy with the highest metallic yield and highest manganese recovery. The silicomanganese alloy produced satisfies the standard chemical specifications, with manganese and silicon contents 68 and 18%, respectively.