A 7-reservoir physical-chemical model of silicon melting in ore-smelting furnaces has been developed with the use of “Selector” software complex on the base 4-reservoir model. The temperature has been chosen as a main characteristics which influence upon smelting technology and various impurity inclusions forming. The results of decisions the models are given for the reservoirs (Si melt and crystal) for the chosen temperature range in introducing 18 independent components. The obtained modeling results were compared with data of different analytical methods.