Abstract: The rate processes of oxidative dearsenication of niccolite ore in microwave oven and in conventional furnace were measured with thermogravimetric technique.The results show that the dearsenication rate of niccolite ore with microwave heating becomes faster than that with conventional heating. Under the conditions of an approximate linear heating and a definite air flow,the oxidative dearsenication process of niccolite ore is mainly controlled by interfacial chemical reaction.The ex- perimental data are in agreement with the kinetic model of linear heating as follows: In{[1-(1-α)~(1/3)]/T}= In (PAM)/(r_oρφE)(1-(RT)/E)-E/(RT) Thus the apparent activation energies of oxidative dearsenication of the niccolite ore containing differ- ent additions have been obtained from the model.

Key words: kinetics, dearsenication, niccolite ore, microwave radiation