Improvement of modeling on the Ppidgeon process for magnesium production by introducing the variable thermophysical properties

The variable thermophysical properties was introduced in the coupling model of heat transfer and reduction reaction in the Pidgeon process to improve the accuracy of numerical calculation. The distribution of temperature and magnesium reduction extent in the briquette layer, and overall magnesium reduction extent in the retort was investigated. The model results show a better agreement with those of industrial production. The characteristic of ?Layer Shift? in the briquette layer during reduction process was clearly presented. It was shown that the reduction reaction occurs only a thin interface. The slag layer producing in the reduction with lower thermal conductivity of 0.4 W?m-1?K-1 greatly impedes the reaction to move forward inside layers, resulting into the slow magnesium production rate in the Pidgeon process. The improved model can provide a more accurate quantitative prediction in magnesium reduction in the Pidgeon process, which is of significance in innovation of key equipment and development of new magnesium production techniques.