Smelting of leached sea nodule residue blended with manganese ore for revovery of manganese

The present work describes the experimental studies carried out for utilization of leach sea nodule residue,
generated from Reduction roasting - Ammoniacal leaching
of sea nodules, for silicomanganese production. Owning to lower manganese content and unfavorable Mn/Fe ratio, leach residue was blended with inanganese ore to maintain the Mn/Fe standard grade silicomanganese alloy production. Smelting of hlended charge mix was carried out in 50 KVA DC' arc furnace and effect of parameters such as blending
ratio, silica addition, holding time etc., on composition of alloy and metal recovery were studied. It was found that charge mix prepared with residue to Mn are mixing ratio of 1:0.8 and I: 0.6 produced standard grade sili- comanganese. The holding time was found to have signi-ficant effect on silicon content of silicomanganese alloy which increased with increasing holding time. Holding time also facilitated the good separation of alloy and slag and thereby increased the recovery of metals. The recovery of manganese was 70% with 60min holding time. It was observed that the blended charge material should have the Mn/Fe ratio of >3.5 and Mn/Si< 2 to produce standard grade sili-comanganese alloy.