China Nonferrous Metallurgy

Continuous Cu smelting technology comprising oxygen-rich side-blowing smelting + multi-lances top converting process + pyrometallurgical anode refining” is the advanced copper smelting technology in the world. In order to reduce the loss of valuable metals in slag, oxygen-rich side blowing slag and multi-lances top converting slag are selected as objects to study the distribution of copper and iron elements in slag in different mineral phases, and the following conclusions are obtained: the copper content in smelting slag and converting slag is 1%-1.7% and 12%-15%, respectively; smelting slag is mainly composed of fayalite, magnetite, glass phase and Cu matte. The slag with high Fe-Si ratio is selected for smelting slag, and a certain proportion addition of pulverized coal can reduce the slag viscosity. The converting slag is mainly composed of calcium ferrite, magnetite and metal Cu phase. Calcium slag is selected for converting slag, and the content of SiO₂ shall be controlled below 3%. The main factors affecting Cu content in slag are slag type, furnace temperature, magnetic iron content, slag layer and matte/blister copper layer thickness.