Investigations on the silicothermic reduction of manganese ore

At present, major portion of the Ferro-alloys produced in India are high carbon (HC) ferromanganese, silicomanganese, ferrosilicon, HC-ferrochrome and charge-chrome. The manganese ferroalloys viz. HC-ferromanganese and silicomanganese accounts for about 42% of total bulk ferroalloy. However, specific plant data on production of low carbon and low phosphorous manganese ferroalloys is not available. The supply of low carbon and low phosphorous manganese ferroalloys has been largely met through imports from Rep. of Korea, Norway, Spain, Russia, Japan and China. The low carbon ferromanganese is often used for production of special steels with low carbon content. Hence, low carbon Ferromanganese is an indispensable ingredient of the special steel making process. In this endeavour, an R&D project on the production of low carbon ferromanganese was attempted. Experiments were carried out to study the effect of charge composition on the silicothermal reduction behaviour of manganese ore in an electric furnace. Results showed that the charge composition particularly the Mn/Si ratio and the flux content greatly influence the process yield. It was concluded that the lime should be added appropriately to make silicate slag by joining with the silica formed by oxidation of silicon during reduction reactions.