Electrothermal co-production of ferrosilicon, calcium carbide and gaseous phosphorus from the chilisay phosphorite

The article presents the results of studies on the use of the high-silicon phosphorites (51,8 % of Ca3(PO4)2, 25,6 % of SiO2) for the co-production of ferrosilicon, calcium carbide and gaseous phosphorus. The studies included the electric smelting a charge in an arc furnace and using the second-order rotatable designs. The conditions of producing FeSi45 ferrosilicon (51,2-54,2 % of coke, 12,5-18,4 % of steel shavings) and FeSi25 ferrosilicon (53-58 % of coke, 39,7- 40 % of steel shavings) with extraction of 65-67,8 % of silicon into the alloy were determined. The second product of the process is technical calcium carbide with a capacity of 129-167 l/kg, in which from 44,8 to 64,1 % of calcium is extracted. At least 99,3 % of phosphorus during the electric smelting is sublimated

Interaction of tricalcium phosphate with products of carbothermic reduction of silicon oxide

The article presents the research results on the interaction of tricalcium phosphate with the products of carbothermic reduction of silicon oxide (SiOg, SiC, iron silicides). The research was carried out by computer thermodynamic modeling using the HSC-6.0 software package. It was established that SiOg, Si, and SiC are highly reactive towards tricalcium phosphate at relatively low temperatures. It was found that, according to the formation degree of gaseous phosphorus from Ca3 (PO4)2, silicon-containing reducing agents form a decreasing series: (SiOg, Si)>SiC>FeSi2>FeSi

Electrothermal co-production of ferrosilicon, calcium carbide and gaseous phosphorus from the chilisay phosphorite

The article presents the results of studies on the use of the high-silicon phosphorites (51,8 % of Ca3(PO4)2, 25,6 % of SiO2) for the co-production of ferrosilicon, calcium carbide and gaseous phosphorus. The studies included the electric smelting a charge in an arc furnace and using the second-order rotatable designs. The conditions of producing FeSi45 ferrosilicon (51,2-54,2 % of coke, 12,5-18,4 % of steel shavings) and FeSi25 ferrosilicon (53-58 % of coke, 39,7- 40 % of steel shavings) with extraction of 65-67,8 % of silicon into the alloy were determined. The second product of the process is technical calcium carbide with a capacity of 129-167 l/kg, in which from 44,8 to 64,1 % of calcium is extracted. At least 99,3 % of phosphorus during the electric smelting is sublimated

Interaction of tricalcium phosphate with products of carbothermic reduction of silicon oxide

The article presents the research results on the interaction of tricalcium phosphate with the products of carbothermic reduction of silicon oxide (SiOg, SiC, iron silicides). The research was carried out by computer thermodynamic modeling using the HSC-6.0 software package. It was established that SiOg, Si, and SiC are highly reactive towards tricalcium phosphate at relatively low temperatures. It was found that, according to the formation degree of gaseous phosphorus from Ca3 (PO4)2, silicon-containing reducing agents form a decreasing series: (SiOg, Si)>SiC>FeSi2>FeSi

Thermodynamics of a Karatau and Aktobe phosphorites mixture interaction when producing phosphorus, calcium carbide and ferrosilicon

Relevance. Associated with the need to increase the level of comprehensive use of phosphorites during their electrothermal processing and to reduce the amount of slag waste generated during the production of phosphorus and polluting the environment. Aim. To conduct computer thermodynamic modeling of the effect of temperature and amount of iron on technological parameters of interaction of a Karatau and Aktobe phosphorites mixture with carbon and iron to produce phosphorus, calcium carbide and ferrosilicon. Objects. Phosphorites of the Karatau and Aktobe phosphorite-bearing basins. Methods. Thermodynamic computer modeling using the HSC Chemistry 6.0 software; rotatable second-order experiment planning technique; geometric optimization of technological parameters. Results. It has been established that depending on temperature in a mixture of Karatau and Aktobe phosphorites with carbon and iron, they participate in interaction:  CaSiO3, SiO2, Si, SiC, SiO(g), MgSiO3, Al2SiO5, Na2SiO3 , Ca(g), CaO, CaC2, CaF2, CaS, Fe, FeSi, FeSiO3, FeP, Fe2P, Fe3P, FeP2, FeO, Fe3Si; Ca3(PO4)2, P2(g), P4(g). An increase in iron amount leads to an increase in the degree of silicon extraction into the alloy, and at 2000 °C reduces the extraction degree of calcium in CaC2 and the silicon concentration in the alloy. Branded calcium carbide with a volume of more than 230 dm3/kg and ferrosilicon FeSi25 are formed from a mixture of phosphorites, carbon and iron at 2077...2088 °C in the presence of 20...21.4 % iron and 43 % carbon (in this case, phosphorus is completely distilled off into the gas phase). Using our proposed method of electric smelting of phosphorites with phosphorus distillation and associated production of ferroalloy, in comparison with the traditional method, the indicator of integrated use of raw materials increases from 43.9 to 62.7...73.6 %, that is 1.43...1 ,67 times. The proposed processing technology helps to increase active reserves of phosphorites and bring low-grade phosphorites of the Aktobe basin into production

Complex electrothermal processing of an oxide zinc-containing ore of the Shaymerden deposit

Oxide ores are potential world raw materials sources of zinc manufacture. Despite a sufficiently high extraction level of zinc and lead known pyrometallurgical methods are characterized by formation of large quantity of industrial wastes therefore a complex use level of these raw materials is low. Hydrometallurgical methods are mainly applied for extraction of nonferrous metals. The present article contains the research results of complex processing an oxide ore of the Shaymerden deposit (Kazakhstan), consisting in the simultaneous production of a ferroalloy, calcium carbide and zinc sublimates from the ore in a thermal-ore arc electric furnace. The researches have been carried out with use of a HSC 5.1 software package (based on a principle of Gibbs energy minimum) and electrical smelting the ore in a monoelectrode arc electric controlled-output furnace. It was found, that in equilibrium conditions in a system ore-carbon-iron gaseous zinc is formed at Т > 1073 K, FeSi at Т > 1573 K, CaC2 at Т > 2073 K, Si at Т > 1673 K. The electrosmelting of ore in an arc furnace using of 38.7-40% coke and 16-28.4% steel cuttings the conversion degree of silicon into an alloy is 75-77%, calcium to calcium carbide 77-81%, zinc to sublimates 99.3%. The ferroalloy obtained contains 19.6-41.3% of silicon, the calcium carbide is characterized by capacity of 110-250 m3/kg, and the zinc sublimates contain 66-67% of zinc. The -suggested method allows to increase the combined usage of the ore from 35.6 to 89.6%

Processing of phosphorites with extraction of phosphorus, obtaining calcium carbide and ferroalloy

The article considers the results of studying the thermodynamic computer modeling of the interaction of phosphorite (Karatau basin, Kazakhstan) with carbon and coke performed using the HSC-10 software package and electric smelting of the phosphorite with coke and steel shavings in an arc furnace. The modeling allowed us to determine the equilibrium extraction degrees of phosphorus into gas (Р2, Р4), silicon into ferroalloy in the form of iron silicides (FeSi2, FeSi, Fe3Si, Fe5Si3, Si) and calcium into CaС2. At temperatures above 1500 °C, regardless of the amount of iron, the extraction degree of phosphorus into gas is more 99%. The resulting ferroalloy contains 21.2-23.8% of Si, 1.6-2.8% of Al; the calcium carbide has a capacity of 288-325 dm3/kg. The extraction degree of silicon into the alloy was 89.8%, calcium in CaC2 – 72.5%, phosphorus into gas – 99.4%. The ferroalloy, formed at the electric smelting of the Chulaktau phosphorite together with coke and steel shavings and containing 24.9-29.8% of Si, is FS25 grade ferrosilicon, and the formed calcium carbide has a capacity of 278-290 dm3/kg and belongs to the third and second grades. The developed technology makes it possible to increase the degree of phosphorites’ comprehensive use two times (up to 87.5%)

Comprehensive Processing of Basalt together with Magnetite Concentrate in Order to Obtain Ferrous Alloy and Calcium Carbide

This article is devoted to basalt reprocessing together with magnetite concentrate in order to obtain ferrous alloy and calcium carbide. The studies have been based on thermodynamic simulation and electric smelting in arc furnace. The thermodynamic simulation has been performed using HSC-5.1 software based on the principle of minimum Gibbs energy. The blend was smelted in arc furnaces. On the basis of the obtained results of combined processing of basalt, it has been established that under equilibrium conditions, the increase in carbon content from 36 to 42 wt % of basalt and concentrate mixture makes it possible to increase the aluminum extraction into the alloy up to 81.4%, calcium into calcium carbide – up to 51.4%, and silicon into the alloy – up to 78.5% [...