The article examines results of studies on the effect of temperature, amount of carbon and pressure on the possibility of obtaining iron silicides and gaseous magnesium by carbon-thermal reduction of silicon and magnesium oxides containing in chrysotile-asbestos waste products. The studies were carried out using the HSC-6.0 software package (Outokumpy) and the second-order rotatable designs (Box-Hunter plans). It has been established that technology allows us to increase α_Si(al), for example, at 1400 °C from 89.6 to 96.75%, reduce undesirable losses of silicon with gaseous SiO from 8.97 to 2.08% and slightly increase α_Mg(gas) from 97.41 to 97.54%. The alloy formed at 1300 °C contains 28.7% of silicon and corresponds to FS25 grade ferrosilicon.

This article examines results of the thermodynamic modeling of interaction of the briquetted tailings obtained at hydrometallurgical leaching of the vanadium-containing quartzites (black shales) with carbon and iron, determination of Si, V, Fe, C equilibrium distribution and optimal conditions for the formation of various grades of ferrosilicon, as well as the electric melting to produce silicon alloys. The research techniques were the method of thermodynamic modeling using the HSC-6.0 software package (Outokumpu), the second-order rotatable designs (Box-Hunter plans) and electrofusion in an arc furnace. It was established that an increase in the amount of iron from 11 to 39% makes it possible to increase the extraction degree of silicon into an alloy up to 72–73% in the temperature of 1800–2000 °C, in the process the silicon concentration in the alloy decreases from 57–65.7 to 40.5–40.9%; FS45-grade ferrosilicon at the extraction degree of silicon in the alloy of 70–72.6% can be formed in the temperature of 1750–2000 °C in the presence of 29–39% Fe, FS50 ferrosilicon is formed at 25.5–35.0% Fe and 1870–2000 °C, and FS65 ferrosilicon – in the temperature of 1895–2000 °C in the presence of 11–12.7% Fe. The FS45-grade ferrosilicon was formed during electric smelting of a charge containing 57% of the briquettes, 21% of coke, 22% of steel chips, and the FS50-grade ferrosilicon – using a charge consisting of 61% of the briquettes, 22% of coke and 17% of steel chips; the silicon extraction degree into the alloys is 73–79%.

The article presents the results of studies on the production of ferrosilicon from iron ore (magnetite) concentrate and quartzite. The studies were carried out by thermodynamic simulation using the HSC-5.1 software package, based on the principle of Gibbs minimum energy and electric smelting of the concentrate together with coke and quartzite in a single-electrode arc furnace. Based on the studies, it was found that, under equilibrium conditions, the interaction of magnetite concentrate with silicon oxide (IV) and carbon is accompanied by the formation of FeSi (> 1200 0C), Fe3Si (> 1100 0C), FeSi2 (> 500 0C), Zng (> 800 0C) Pbg (> 1200 0C); the degree of silicon extraction into the ferroalloy depends on the ratio in the SiO2 / Fe3O4 mixture, decreasing from 85.6 to 66.1 (for example, at 17000С) with an increase in the SiO2 / Fe3O4 ratio from 0.42 to 1.25. When melting a mixture containing 70% concentrate, 11% quartzite, 19% coke, a ferroalloy containing 15-18% Si. The resulting ferroalloys are graded from FeSi15 to FeSi45.

This article presents the results of thermodynamic and experimental studies on the joint processing of a mixture of Shalkiya deposit zinc–lead sulfide ore and its concentration tailings in the presence of coke and magnetite. Using the HSC-6.0 software package, it was established by thermodynamic modeling that the silicon-containing products of the SiO₂ reduction in the system under consideration are FeSi, Si, Fe₃Si, Fe₅Si₃, FeSi₂, FeSi_2.33, and SiOg, which, based on the starting reduction temperature, form an increasing series: Fe₃Si (1200 °C); Fe₅Si₃, Si (1400 °C); and SiOg, FeSi₂, FeSi_2.33 (1500 °C). The smelting of the zinc–lead sulfide ore and concentration tailings mixture in the case of replacing 55% of the iron contained in the magnetite concentrate with steel shavings iron allowed us to produce FeSi45 ferrosilicon (41.9%–42.1% Si), with the extraction of 85% of the silicon in it, and sublimates containing 26.03% zinc and 13.47% lead, with the extraction of 97% of the zinc and 99% of the lead in them. In comparison with the initial ore-tailings mixture, the resulting sublimates are 11.83 times richer in zinc.

The article presents the results of studies on the influence of time, the amount of steel shavings and coke on the electric melting of ferrosilicon manganese dusts to obtain a ferroalloy. The research was carried out by the method of rotational planning of the second order (Box-Hunter plans) and by electric smelting of dust in laboratory ore-thermal arc furnace. Dust from the production of ferromanganese by LLP Taraz Metallurgical Plant, coke and steel shavings were used during the research. It was determined that to achieve αSi≥70%the process must be carried out in the presence of 25% coke and 8.1-9% steel shavings from the mass of dust for 55.8-60 minutes, to achieve αMn in an alloy of 80-85% the process must be carried out in the presence of 25% coke, 5.7-9.0% steel shavings for 41.2-54.4 minutes. When melting the charge containing 75.2% of dust, 18.8% of coke, 6% of steel shavings, within 60 minutes the weight of the ferroalloy was 258 g (38.8% of the weight of the charge or 51.6% of the weight of dust). The degree of extraction of manganese into the alloy was 82.3%, silicon - 66.1%. The resulting ferroalloy belongs to ferrosilicon manganese of the FeMnSi12 grade.

The article covers the results of researches on thermodynamic modeling of ferroalloy and calcium carbide obtaining from basalts of deposit Dubersay. The software package HSC-5.1, based on the principle of Gibbs energy minimum uses in the study. The influence of temperature (from 500 to 2500 °C) and the amount of carbon (from 40 to 60 % of the basalt mass) in the basalt–Fe–nC system was determined. It has been established that iron silicides are formed at T ≥ 1300 °C, Si at T ≥ 1400 °C, CaSi and Al at T> 1700 °C and CaC2 – at T ≥ 1800 °C. An increase of the amount of carbon from 40 to 60 % allows rise the degree of distribution of Si in the alloy up to 94 %, calcium in CaCl2 – up to 62.3 %, aluminum – to alloy up to 93.9 %. An increase of the amount of carbon allows increase the silicon concentration in alloy up to 55 % (at 1800 °C), aluminum – up to 17 % (at 2000 °C) and calcium carbide capacity – up to 350 dm3/kg. The method of rototable planning of the second order allows find equations of regressions of the influence of temperature and amount of carbon on the equilibrium distribution of silicon, aluminum, and calcium between the ferroalloy and calcium carbide. On the basis of this equations were determined, that within the temperature range 1956-1996 °C from the Dubersay deposit basalt, the ferroalloy with a content of ΣSi and Al 60.8-65.4 % (including 12- 15 % Si) and calcium carbide with a capacity of 250-300 dm3/kg are formed. Wherein degree of recovery into the alloy for silicon is 91-91.4 % and for aluminum is 63-75.1 % and calcium – into CaC2 is 60-60.7 %. The resulting ferroalloy by the content of silicon and aluminum can be attributed to the complex ferroalloy – ferrosilicoaluminium, calcium carbide – to the industrial product of grade from 3 and up to the highest.