KINETIC-STUDIES OF REDUCTION OF COO AND COWO4 BY HYDROGEN

The present work deals with the studies of the kinetics of reduction of CoO and CoWO4 in flowing hydrogen gas by thermogravimetric method. The reduction studies for CoO were carried out in the temperature range of 637 to 837 K, while for CoWO4 reduction, the temperature range was 837 to 1173 K. In the case of the reduction of CoWO4, the reaction products after reduction were analyzed by X-ray diffraction as well as scanning electron microscopy. The activation energy for the reduction of CoO was found to be of 54.3 kJ/mol. Cobalt tungstate was reduced to a mixture of Co7W6 and W, and the activation energy for the reaction is 90.0 kJ/mol. The results are discussed in the light of the reduction kinetics of other transition metal oxides and tungstates under similar conditions.