Removal of metallic and non-metallic impurities by hydrogen plasma-arc melting

In this paper, an extensive review of impurities removal from liquid metal by hydrogen plasma-arc melting has been carried out, and the removal activity of various elements has been discussed. The removal of non-metallic (S, N, O, C) and Metallic (Fe, Cr, Ti, V, Zr, Mo, Al, Mn, Si, Ge, Sn, Cd, Sb, Ga, In, Pb, Y) impurities from the different liquid metals (Fe, Co, Ni, Hf, V, Cr, Zr, Ti, Tb, Nb, Mo) have been studied. The impurities from various metals can decrease to less than 1 ppm by hydrogen plasma arc melting (HPAM) with various amounts of H2+Ar plasma arc exposure. It suggests that removing metallic and non-metallic impurities by HPAM is more effective than other processes like electron beam melting (EBM), vacuum arc melting (VAM) etc., due to high vacuum and weight loss concerns. The present review concluded that HPAM could be considered an environment-friendly route for impurities removal in industry, especially for the desulphurization of liquid steel.