A continuous stirred-tank reactor (CSTR) model has been developed for the continuous carbonation of the sodium aluminates solution (SAS) which is a key process in sintered alumina production. Based on the mechanistic analysis of the continuous carbonation, a kinetic model established at laboratory scale was scaled up to the industrial continuous carbonation of SAS. A CSTR model was formulated for the process under normal operation conditions. The remaining unknown model parameters were estimated from the industrial data and the validation results show that the model can predict the composition concentrations in the carbonated solution by 90% majority with the relative errors within +/-5% compared to industrial data. The model developed will be further evaluated for on-line prediction and control in the corresponding industrial process.