Technological experiments of joint smelting of lead intermediate products, recycled materials and high-sulfur copper-zinc concentrate

The purpose of this work is to improve the technological indicators of the existing mine contractile smelting technology by joint smelting of intermediate products, recycled materials of lead production with high-sulfur copper-zinc concentrate. It is established that during the smelting of copper-zinc concentrate which is difficult to process, high selective extraction of copper into matte and zinc into slag is achieved in one stage. The method consisted in the joint smelting of lead intermediates and high-sulfur copper-zinc concentrate in an electric furnace at a temperature of 1250 degrees C under conditions of sequential blowing of the melt with air, then with natural gas. It is established that when the melt is purged with air and natural gas for 20 minutes, an equilibrium distribution of metals between the melting products is achieved. It is shown that simultaneous use of copper-zinc concentrate as a sulfidizer reduces the content of copper and lead in slag, increases the extraction of arsenic and antimony into the dust. Consumption of coke and quartz flux is reduced in comparison with the existing technology from 6.7 to 2.5% and from 12.5 to 2.8% of the initial feed weight, respectively, which significantly reduces material and energy costs of the process. As a result of extensive laboratory testing, the optimum composition of the new charge has been selected. Metal distribution between smelting products of the new charge with addition of 30% of high-sulfur copper-zinc concentrate was established. High recovery of copper to the matte up to 94.8%, against 83.7% according to the existing technology; lead to the rough lead - up to 93.6%, against 70.8%; zinc to the slag - up to 94.7%, against 83.7%; arsenic to the dust - up to 91%, against 69.5% and antimony to the dust - up to 92.3%, against 60.0% according to the existing technology.