Fundamental Researches on Smelting of Sulphide Ores. II : On the Equilibrium in the Reduction of Solid Ferrous Sulphide by Hydrogen Gas

The equilibrium in the reduction of solid ferrous sulphide by hydrogen gas was investigated with the aid of the flow method over the temperature range 775°~872℃. The equations for the temperature dependence of the equilibrium constant and of the standard free energy change of the reaction were represented as follows : FeS(β)+H_2= Fe(β)+H_2S ; log K_p=-3, 098/T+0.141, ΔF°=14, 170-0.645T. Combining the equations above mentioned with the known ones of formation of' hydrogen sulphide, the following equations for the dissociation of solid ferrous sulphide were obtained : 2FeS(β)=2Fe(β) +S_2 ; log P_<S_2>=-15, 582/T+5.382, ΔF°=71, 270-24.62T. Using these results obtained and the known thermodynamical data, the heat change and the standard free energy change of formation of solid ferrous sulphide from the elements were calculated as follows : Fe(a)+S(r)=FeS(a) ; ΔH298.1=-22, 610, ΔF°298.1=-23, 110.