Abstract:Combined with slag type test of top-blowing furnace for treatment of waste circuit boards, FactSage software was used to theoretically analyze slag type determination process of top-blowing furnace for treatment of waste circuit boards, and metallurgical phase diagram under ideal slag type was drawn. The results indicate that focus of slag type control for treatment of waste circuit boards in top blowing furnace lies in control of Al2O3 composition. The ideal slag type is SiO2-CaO-Al2O3-FeO quaternary slag type, and content of each component ranges from SiO2 of 28% to 35%, CaO of 18% to 25%, Al2O3 of 6% to 13%, FeO of 16% to 20%, and the total quaternary components are more than 80%. Under the ideal slag type, overflow and continuous slag discharge can be realized, metal and slag are separated completely, total recovery rate of Cu, Au, and Ag is all greater than 95%, and average copper content in slag is less than 0.7%. The slag type range and phase diagram theory can provide a theoretical basis for slag type research and production practice of various molten pool smelting furnaces for processing waste circuit boards.