Theoretical and experimental substantiation of obtaining an alloy from flotation tailings of lead-zinc sulfide ore

Abstract

The article presents the results of thermodynamic and experimental research on the processing of cinders from the firing of Shalkiya deposit lead-zinc ore tailings with the production of siliceous ferroalloys. Thermodynamic modeling carried out using the HSC-6.0 complex based on the Gibbs energy minimization principle showed that the interaction occur with the formation of CaSiO<sub>3</sub>, FeSiO<sub>3</sub>, MgSiO<sub>3</sub>, K<sub>2</sub>OˑSiO<sub>2</sub>, FeSi, Fe<sub>5</sub>Si<sub>3</sub>, SiC, Fe<sub>3</sub>Si, Si, SiO<sub>g</sub>, FeSi<sub>2.33</sub>, FeSi<sub>2</sub>, CaSi, Zn, Zng, Pb, Pb<sub>g</sub>; an increase in the iron amount in the system allows increasing the silicon extraction degree into the alloy at 1800°C to 76%, to reduce the silicon concentration in the alloy from 41 to 24%; FS25 grade ferrosilicon formed at 1752-1867°C in the presence of 88-100% iron, and FS45 grade ferrosilicon – at 1863-1900°C and 20-22.4% iron. Electric melting of a charge containing 63.83% calcined cinder of tailings, 19.15% coke, and 17.02% steel chips allows to obtain FS45 grade ferrosilicon (44.1-43.9% Si) with the extraction of 69.7% silicon and sublimates with the content of 32-38% zinc and lead. The results obtained allow complex processing of lead-zinc sulfide ore tailings with the extraction of not only non-ferrous metals, but also silicon in the ferroalloy.