The ways of increasing the extraction of the sum of non-ferrous metals in matte during melting of sulfide raw materials in the Vanyukov furnace are considered. The analysis of smelting with regard to the peculiarities of Nadezhda Metallurgical Plant technology: high content of copper and nickel sulfides in the charge. Such a composition of the charge leads to unacceptable losses of non-ferrous metals when using conventional methods of smelting control. In the process of analysis the sources of chemical and mechanical losses of non-ferrous metals were revealed. We suggest a method of reducing chemical losses of non-ferrous metals with slag by means of control and optimal regulation of sulphur dioxide content in flue gases. The ratio between oxygen and natural gas flow rate is chosen as a control variable in the sulfur dioxide control circuit.