Silicomanganese production from manganese nodules leach residue by blending with manganese ore

The leached residue generated by reduction-roast-ammoniacal leaching of manganese nodules at NML, Jamshedpur was utilized for the production of silicomanganese alloy, which is used as deoxidizer and for alloying purpose in steel making process. The studies involved blending of leached residue with high grade manganese ore, mixing of blended materials with quartzite, dolomite and coke and their smelting in 50 KVA DC arc furnace. Smelting studies showed that the composition of alloy produced from charge containing residue to ore blending ratio of 1:0.6 and 1:0.8 conformed to standard grade silicomanganese specified by Bureau of India Standards. 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 silicomanganese alloy. The holding time was found to have significant 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 metal. The recovery of manganese was 70% with 60 min. holding time.