The reaction of potassium carbonate with ferric oxide was investigated thermogravimetrically. Both non-isothermal and isothermal conditions were used for the kinetic study of this reaction. The reaction between K2CO3 and Fe2O3 yields KFeO2 and the reaction occurs at lower temperature than the decomposition temperature of pure K2CO3. Arrhenius parameters were derived from the experimental data and a reaction mechanism for the formation of KFeO2 is proposed.