This article presents the results of production experiments to optimize the modes of silicon smelting in an industrial arc furnace. The main factors of the melting process are the size of the fractions of the charge components and the temperature regime of heating. The rate of charge heating in the reaction zone in the temperature range from 950 to 14100C has a special effect on productivity. In this temperature range, the formation of refractory silicon carbide on pieces of quartzite was established, which causes a drop in the magnitude of the electric current in the reaction zone and its freezing. The gornisage, which is formed, displaces the electrodes into the zone of greater charge electrical conductivity - up, which leads to an increase in silicon monoxide emissions through the reduced charge layer. Correction of such a process requires an increase in the temperatures in the reaction zone and the duration of the melt. A method has been developed for calculating the size of quartzite fractions, depending on the power of the furnace and the size of the reaction zone. An example of a simplified calculation is proposed.