This study explored the feasibility of the carbon-free smelting of ferrochrome (FeCr) using a complex reducing agent—ferroaluminosilicalcium alloy (FeAlSiCa)—produced from industrial waste and ferrosilicochrome (FeSiCr) dust. Laboratory-scale smelting experiments were conducted with Cr concentrate and the addition of FeAlSiCa and FeSiCr dust under four different reducing agent contents: (1) 10% deficiency, (2) stoichiometric amount, (3) 10% excess, and (4) 20% excess. It was found that with a 10% excess, a nearly complete reduction of Cr₂O₃ was achieved (residual content in slag ≤ 0.9%), resulting in the formation of low-carbon FeCr (LC FeCr) with a high nitrogen content (up to 2.6%). Based on a thermodynamic analysis of the reduction reactions, the high reactivity of the FeAlSiCa and FeSiCr components (Ca, Al, and Si) at 1500 °C was confirmed. These reactions were exothermic, which demonstrates the energy efficiency of using these ferroalloys as reducing agents in FeCr smelting. The resulting slag is structurally stable and does not disintegrate over time, making it a promising candidate for potential reuse as a secondary raw material. The results demonstrate the promise of the proposed technology for both reducing the carbon footprint of ferroalloy production and lowering the cost of the metallothermic production of LC FeCr.

This study investigates the use of the complex reductant FeAlSiCa as an alternative to the conventional FeSiCr in the EAF smelting of FeCr. The smelting process using FeAlSiCa is characterized by a stable furnace operation, active discharge of metal and slag, and effective phase separation. It was found that a 20% excess of FeAlSiCa over the stoichiometric requirement leads to a sharp increase in Si content in the FeCr alloy, with approximately 85% Cr recovery into the metal. A stoichiometric amount of FeAlSiCa results in a metal with 1.5–1.6% Si content and about 80% Cr recovery. A comparable Cr recovery using FeSiCr was achieved only when applying a 20% excess of that reductant. The use of FeAlSiCa also holds promise for technological sustainability due to its low production cost and the utilization of waste materials during its synthesis. The resulting slags are solid and rock-like and show no signs of disintegration after storage for more than 45 days.

The article presents the results of a study on the production of a complex chromium–manganese–silicon-containing ferroalloy in a large-scale laboratory ore-thermal furnace using man-made waste—chromium-containing aspiration dust obtained during smelting of high-carbon ferrochrome, fines (−5 mm) of iron–manganese ore currently stored in landfills, and finely dispersed coal sludge formed during enrichment. A single-stage technology for the production of a new complex chromium–manganese–silicon-containing ferroalloy by carbothermal reduction is proposed. A metallurgical assessment of the initial charge materials was carried out by the X-ray diffraction (XRD) phase analysis, and metal samples of the obtained ferroalloy were studied by scanning electron microscopy (SEM) in combination with energy dispersive spectroscopy (EDS). The resulting ferroalloy has a complex microstructure with a predominance of carbide and intermetallic phases. A high degree of extraction of chromium (up to 80%), manganese (up to 75%), and silicon (up to 35%) was recorded. The average chemical composition of the obtained ferroalloy, wt.%: Cr—37.41; Mn—17.31; Si—11.84; C—3.81; P—0.14; S—0.02. The slag formed during the smelting of the ferroalloy has satisfactory technological properties: it is characterized by good fluidity, and it actively exits the furnace by gravity. Entanglement of metal kings in the slag is not observed. The results obtained confirm the technological feasibility of the utilization of technogenic raw materials for the production of complex ferroalloys of the FeCrMnSi type.

This article presents the results of thermodynamic modeling of the process of obtaining chromium-manganese ligature from ferro-manganese ore and dust from crushing ferrosilicochrome (FeSiCr). The calculations were performed using the “HSC Chemistry” software package, where dust from crushing FeSiCr was used as a reducing agent. The analysis was performed by varying the reducing agent dust FeSiCr from 10 to 100 kg in increments of 10 kg per 100 kg of ferro-manganese ore, at temperatures of 1400°C, 1600°C and 1800°C. The mechanism of combined metallothermic reduction of chromium (Cr), manganese (Mn), and iron (Fe) was studied in a multicomponent Fe-Cr-Mn-Si-Al-Ca-Mg-O system. Based on thermodynamic data, it was found that the optimal consumption of reducing agent is 50 kg per 100 kg of ore, and the most effective melting temperature is 1600 °C, at which the best yield of chromium-manganese ligature is achieved. Additionally, laboratory tests were conducted under specific conditions, resulting in experimental samples of the ligature with the following chemical composition, %: Fe – 28.39, Cr – 16.58, Mn – 32.55, Si – 3.56.

This study investigates the production of chromium–manganese ligature by a metallothermic process using complex silicon–aluminum reducing agents. Low-grade chromium and iron–manganese ores from the Kempirsai and Kerege-Tas deposits in Kazakhstan were used as raw materials, while the reducing agents included alumosilicomanganese alloy (AlSiMn) and ferrosilicoaluminum (FeSiAl). Thermodynamic calculations were performed with HSC Chemistry 10 at 1400–1800 °C and reducing agent dosages of 10–100 kg per 100 kg of ore charge. Crucible smelting experiments were then carried out in a Tamman furnace, followed by large-scale laboratory trials in a 100 kVA refining electric furnace to verify reproducibility, with a total of 14 runs. The chemical composition of the ligatures varied depending on the reductant: with AlSiMn the alloy contained Fe—23.14%, Cr—53.74%, Mn—20.03%, and Si—3.06%; with FeSiAl, it contained Fe—42.01%, Cr—25.74%, Mn—27.15%, and Si—5.05%; and with FeSiCr dust, it contained Fe—34.45%, Cr—21.45%, Mn—39.82%, and Si—4.24%. X-ray diffraction (XRD) and scanning electron microscopy (SEM) analyses confirmed the presence of α-(Fe,Cr,Mn), FeSi, and Cr₅Si₃ phases. The results demonstrate the efficiency of complex silicon–aluminum reducing agents and the ability to regulate the composition of chromium–manganese ligatures by the selected reductant.

This study investigates the feasibility of producing an Fe-Cr-Mn complex alloy through the recycling of technogenic wastes from metallurgical operations. The feed materials comprised chromium-bearing dust collected from the gas-cleaning system of high-carbon ferrochrome production, iron–manganese ore fines (<10 mm) from the Tur deposit (Kazakhstan), and coal sludge used as a carbonaceous reducing agent. Thermodynamic modeling of the carbothermic reduction of Cr and Mn oxides and the predicted distribution of components among the metal, slag, and gas phases were performed using the HSC Chemistry 10 software package over a high-temperature range. At 1800 °C, the calculated chemical composition of the target alloy was as follows (wt.%): Cr-35.84, Mn-24.47, Si-16.25, Fe-22.63, and C-0.82. To validate the modeling results, experimental smelting trials were carried out in a 100 kVA electric arc furnace, producing both metallic and slag phases. The average composition of the metal phase was (wt.%): Cr-37.17, Mn-14.46, Si-11.48, Fe-33.23, C-3.48, P-0.15, and S-0.021. The experimental results indicate the formation of a Cr-Mn alloy with elevated Cr and Fe contents and a noticeable C level, confirming the carbothermic nature of the reduction reactions. The composition and microstructural features of the smelting products were examined by scanning electron microscopy coupled with energy-dispersive spectroscopy (SEM/EDS). The findings demonstrate that the combined use of technogenic raw materials and a carbonaceous reductant enables the production of a Cr- and Mn-enriched metallic phase under satisfactory slag-forming conditions. Overall, the results confirm the potential of a resource-saving approach for valorizing fine technogenic wastes in the production of complex ferroalloys and for improving the recovery of target elements through optimization of the charge composition and smelting parameters.