Removal of C, Si, Mn, S and P in Iron Melt under Hydrogen Plasma

The removal of carbon, silicon, manganese, sulfur and phosphorus in iron melt requires oxidizing followed by a reducing environment. This study showed that their simultaneous removal is feasible under hydrogen plasma. The trials were carried out in a 4-kg capacity transferred arc plasma furnace that was locally built. The removal of various impurities from the molten iron was investigated by utilizing various H-2-Ar gas mixes with a 70-min exposure/reaction period. The impurities, in general, followed the removal order of C, S, Si, Mn and P without changing experimental conditions. The maximum removal was achieved using 1 L H-2+1 L Ar gas mixture/minute flow rate. After 70 min of plasma gas exposure time, nearly 99% C, 81% S, 76% Si, 41% Mn and 31% P removal was noticed. This indicates the simultaneous removal of all impurities from the iron melts under hydrogen plasma in a single step. It appears that carbon and sulfur are removed by the gaseous phases formed by reacting with hydrogen, while manganese and silicon form hydride to be removed via the vapor phase. Phosphorus also seems to be removed by gaseous compound formation.