Theory and Technology of Manufacturing a Ferroalloy From Carbon Ferrochrome Dusts

Abstract

The article contains the research results of obtaining a ferroalloy from a carbon ferrochrome dust containing 30,2% of Сr2O3, 23.4% of SiO2, 32.7% of MgO, 5.0% of FeO, 1.6% of CaO, 4.5%of Al2O3, 2.3%of C, and 0.3 %-others. The studies were carried out by a thermodynamic modeling method using the HSC-5.1 software package (Outokumpy) based on the principle of the Gibbs energy minimum, the Box-Hunter rototable planning technique and electric melting of the dust in an arc furnace. It was found that the interaction of the dust with carbon under equilibrium conditions and in the presence of iron leads to formation of Cr4C(T>10000C),Cr3C2, Cr7C3,Cr (T>11000C), FeSi (T>13000C), SiC (T>14000C), SiOg and Si(T>15000C). In the temperature range of 1745-19000C and in the presence of 18-34% of carbon and 8% of iron of the dust mass, the resulting ferroalloy contained 18.5-25.2% of Si and 46.8-49.4% of Cr (in this case the silicon extraction degree into the alloy was 60.0-64.4%, the chromium one–99.8%). When the electrosmelting the granulated dust together with coke and steel shavings, the chromium extraction degree into the alloy was 98-99%, the silicon one–53-57%; the obtained ferroalloys containing 18.3-21.9% of silicon and 45.6-53.6%of chromium meet the requirements to FeCrSi23-grade ferrosilicochromium.

Thermodynamic Diagram Analysis and Smelting of Complex Fe-Cr-Mn-Si Ferroalloy

“…The kinetics of these processes can be significantly complex, as they involve solid-state reactions and gaseous diffusion. Low extraction is also attributed to the high volatilization of these elements into the gas phase due to the absence of a filtering layer of charge materials in ore thermal furnaces, where such alloys are more commonly performed [26,27]. The presence of a significant amount of condensate in the furnace's graphite tube confirmed the substantial volatilization of the principal elements.…”

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

“…Bearing in mind the opposite nature of the iron influence on the silicon transition degree into the alloy and the concentration of this element in it, further research to determine the process parameters that provide the conditions for obtaining grade ferrosilicon (at αSi→max.) was carried out by the second-order rotatable planning method (Akhnazarova and Kafarov, 1985) followed by geometric optimization, which we described in the production of ferroalloys from various natural and technogenic raw materials (Shevko et al, 2018;Shevko et al, 2020;Shevko et al, 2021b). In this case, the independent variables were temperature (T, °С) and iron amount (Fe, % of the cinder mass).…”

Assessment and Analysis of Occupational Risks in Underground Mining of Polymetallic Ores

“…For example, the author [22] defines risk management as a process of its control, covering all types of activities. And according to [23], risk management is reduced to developing a mechanism for minimising it by determining its effect and all characteristics. The authors [24] believe that excluding the monitoring of the enterprise environment and the environment in which the enterprise is included, from the cycle of risk analysis predicts the short-term nature of all decisions taken in the chosen policy.…”