Question

One of the problems with the roasting technique of material processing is that it generates sulfur dioxide, a pollutant. A suggestion for avoiding the problem is to mix the sulfide concentrate with powedered lime and then to reduce by hydrogen, the idea being that coupled reactions such as:

PbS + H₂ = Pb + H₂S

H₂S + CaO = H₂O + CaS

might take place, producing metal without evolution of sulfur dioxide. The solid reaction products would then be separated by some physical means (e.g., sink-float). Using the thermodynamic data contained in the Ellingham diagrams, evaluate the feasibility of carrying out these coupled reactions at 800^oC?

*Question taken from "The Production and Processing of Inorganic Materials" question 8.2

Answer 1