Kinetics of carbothermic reduction of magnesia and zinc oxide by thermogravimetric analysis technique

The rates of carbothermic reduction of magnesia and zinc oxide have been investigated using a thermogravimetric analysis technique under argon and CO atmospheres. The experimental results show that zinc oxide can react with carbonaceous materials more easily than magnesia. Both magnesia and zinc oxide can be reduced by charcoal at a lower temperature than by graphite. The carbothermic reduction of magnesia starts at a higher temperature in CO atmosphere than in Ar atmosphere. A kinetic model was developed to analyze the experimental results. The average activation energy value of carbothermic reduction by charcoal calculated from the data of non-isothermal experiments is 210 kJ/mol for magnesia and 222 kJ/mol for zinc oxide, respectively.