On the basis of the experimental results, the relation between the efficiency of recovering element chromium and proportion of metal aluminium in material and the energy sent out by every kilogram material was found out, At the same time, the relation between the contents of element Fe, Si, Al in the product and the proportion of metal aluminium in material was obtained. Then the mathematic model was established. According to this model and using the material containing 82.85%Cr2O3 (average value, it is far below 94% which is required before), the metal chromium was smelted. The average efficiency of recovering element Cr is 85.44%.