| The reduction of some transition metal sulfate, such as Ag₂SO, CuSO, NiSO₄, CoSO, FeSO, MnSO, etc., by hydrogen had been studied over a range of 0.2 to 1.0 atm in hydrogen partial pressure. 1) The beginning temperature of reduction was found to be directly proportional to the standard free energy(G) of formation of sulfates. T(°K)=-4.71G-223.8 2) Reduction solid products of sulfates by hydrogen may lead to the following one, (l) metal, (2) sulfide, (3) mixture of sulfide and metal. 3) Reaction rate were fitted to da/dt＝kf(a)P_(H₂) And the rate of reduction was found to be directly proportional to the hydrogen partial pressure in some range. 4) The apparent activation energy for the reduction is found to be 22.1㎉/㏖ for CuSO₄, 23.5㎉/㏖ for NiSO₄, 18.1㎉/㏖ for CoSO₄, 33.2 ㎉/㏖ for Ag₂SO, respectively. |
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