REACTIVITY OF MECHANICALLY ACTIVATED PYRITE

We have studied the decomposition of pyrite FeS2 in the temperature ra nge 748-834 K. The decomposition proceeded, in a dynamic argon atmosph ere, according to the equation FeS2(s) --> FeS(s) + S(g) and was accel erated by mechanical activation in a planetary mill. We have found tha t reaction is sensitive to defectiveness of the structure of FeS2 and the estimation of its structure sensitivity depends on an adequate cho ice of the method used for measuring the surface area of the particles . Longer times of mechanical activation bring about the effect of reco mbination of fine particles of pyrite, which retards the reaction.