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

The equilibrium in the reduction of solid lead sulphide by hydrogen gas was studied by means of the dynamical method over the temperature range 582~775℃. The equilibrium constant and the standard free energy change for the reaction were represented by the following equations as a function of temperature : PbS(s)+H_2 =Pb(1)+H_2S ; log Kp=-3, 500/T+1.601, ΔF°=16, 009-7.323T. By combining the equations with the known ones of hydrogen sulphide gas, the following equations were obtained with regard to the dissociation of solid lead sulphide : 2PbS(s)=2Pb(1)+S_2 ; log P_<S_2>=-11, 386/T+8.302, ΔF°=74, 950-37.97T. And also using the results and the existing data, the following thermodynamical values in relation to the formation of solid lead sulphide were obtained : Pb(s)+S(r)=PbS(s) ; ΔH298.1=-22, 280, ΔF°298.1= -22, 330.