Technology for extraction of Pb, Cu, Zn from a feed based on lead cake from leached dust generated by reduction-oxidation blowing of melt

The paper presents the theoretical basis and results of processing a mixture of complex types and compositions, based on lead cake, obtained after the preliminary removal of arsenic from dust and its subsequent leaching with sulfuric acid. The main goal of the technology is to involve the processing of substandard intermediate products of lead production together with lead cake and the selective extraction of non-ferrous metals into commercial products: copper into matte; lead - into rough lead: zinc - into slag. Choice of the composition of the feed charge was carried out taking into account the volumes obtained in production and is represented by the following structure, %: lead cake - 50; copper-lead matte – 40; quartz flux – 10. It has been established that the best results, ensuring high complex extraction of copper, lead, zinc and arsenic into the targeted smelting products, are achieved with a consumption of natural gas 1.4 times higher than its consumption from the stoichiometric required quantity (SRQ) for the reduction of lead compounds to metal lead. The optimal time for blowing the melt with natural gas is 15 minutes. The optimal oxygen consumption when blowing the intermediate matte obtained after the first stage was 1.1 times higher than its stoichiometric required amount (SRQ) for the oxidation of zinc and iron sulfide with their further transfer in the form of oxides to slag. The duration of matte blowing is 10 minutes. With the optimal established parameters, high technological indicators of the technology were achieved: extraction of lead into rough lead - 98.6%; copper in matte – 98.5%; zinc in slag – 94.1%.