Dephosphorisation of high carbon ferromanganese using BaCO 3 based fluxes

Dephosphorisation of ferromanganese under oxidising conditions is difficult to achieve without significant manganese loss. The present study identifies the suitable conditions for selective removal of phosphorus using BaCO3 based fluxes. Initially Ba–P–O predominance diagrams for both standard and non-standard conditions were constructed, and studied to identify the best possible flux composition for selective removal of phosphorus without significant manganese loss. Experiments were conducted by varying the flux composition (BaCO3, BaF2), flux rate, metal composition, and temperature under the desired conditions for phosphorus removal. A method was evolved to melt BaCO3 based flux at temperatures below 1400°C. A flux composition consisting of 66% BaCO3 and 34% BaF2 added at the rate of 16 wt-% of the amount of ferromanganese charged was found to be most effective.