Pyrometallurgical units’ efficiency is determined by their heat operation. TROF-converter heat operation was investi- gated at treatment of copper containing materials and brass scrap. The main goal of this research was to compose the heat balance and to analyze incoming and output heat components.The main incoming heat streams are: heat of burning gas, heat of exothermic reactions and especially zinc and iron oxi- dation. Output heat streams are represented by heat losses through refractory lining, heat losses with exhaust gases and amount accumulated by lining