Abstract
The presence of nonferrous metals, particularly copper, in the chalcopyrite-magnetite ore of the Irisu deposit precludes its use in metallurgical production. This requires preliminary metal extraction. This article presents the results of a study on the extraction of nonferrous metals from Irisu ore by chloride sublimation roasting. The study was conducted using computer thermodynamic modeling and the HSC-10 software package, which is based on the minimum Gibbs free energy principle. Calcium chloride was used as the chlorinating agent. The effects of temperature and pressure on the chloride sublimation of nonferrous metals and the behavior of iron and sulfur during this process were determined. It was established that the interaction of Irisu ore with calcium chloride is accompanied by the formation of gaseous chlorides: AgCl(g), CoCl2(g), Cu2Cl2(g), Cu3Cl3(g), Cu4Cl4(g), CuCl(g), FeCl2(g), PbCl(g), PbCl2(g), ZnCl2(g). A decrease in pressure from 0.1 to 0.001 bar reduces the temperature of complete chloride sublimation of copper to 683°C, zinc – 597°C, lead – 593°C, silver and cobalt to 700°C. The degree of chloride sublimation of iron at 700°C is only 0.24%. In the cinder, it is present to a greater extent in the form of Fe3O4 and to a lesser extent in the form of Fe2O3 and FeO. Under these conditions, sulfur is almost completely (99.99%) converted into SO2. Chloride sublimates formed at 700°C and 0.001 bar contain 33.94% copper, 11.57% lead, 5.98% zinc, 2.88% cobalt, 0.2673% silver and 5.49% iron. In this polymetallic concentrate, compared to the ore, the content of copper, zinc and silver increased by 44.6 times, lead – by 44.5 times, cobalt – by 45.3 times.