The solid state reduction kinetics by carbon monoxide of sodium sulfate mixed with sodium titanate are studied in a thermogravimetric system at 670-750-degrees-C. It is found that the reduction of this mixture is much faster than that of pure sodium sulfate. The conversion-time curves of the model mixtures are sigmoidal in shape and well described by the nucleation and growth kinetic model. The activation energy is 420 kJ/mol. The influence of the CO and CO2 concentration, mass fraction of sodium titanate and addition of sodium sulfide catalyst are investigated. Based on the present experiments and literature results, a mechanism is proposed for the CO reduction.