Determination of dissolved sulfur and Mg‐S, Mg‐O equilibria in molten iron

Experiments on the extraction of sulfur from the sulfides and oxy‐sulfides such as FeS, MgS, CaS, BaS, RE2S3 and RE2O2S (RE ‐ rare earth metals) by hydrogen reduction were carried out at 600 – 900°C by means of hydrogen reduction‐polarographic analysis method. The reduction degree of various sulfides by H2 at 800°C is in decreasing order as follows: FeS > MgS ≥ RE2S3 > RE2O2S ≥ CaS ≅ BaS. The equilibrium constants for reaction MgS(s) = [Mg] + [S] and MgO(s) = [Mg] + [O] obtained by using vapour‐liquid equilibrium method are: KMgS = 2.0·10−4 at 1873 K, log KMgO = 1.27 ‐ 13670/T, eOMg = 644.5 ‐ 1406000/T.