The research presented in the article is devoted to the study of the influence of phase compounds on the friability of the Fe-Si-Mn-Al complex alloy. The urgency of the problem lies in the development of technology for producing a non-scatterable alloy from manganese-containing ores and high-ash coals. The main goal of this work is to determine the range of alloy compositions and the resulting phases that affect the dispersibility of the alloy, which is critically important for its industrial implementation. Research methods include thermodynamic diagram analysis (TDA) using data on the standard enthalpy of formation of intermetallic compounds, as well as experimental tests in an ore-thermal electric furnace with a capacity of 200 kV*A. The results show that Fe-Si-Mn-Al complex alloys form a variety of silicide and aluminide phases, including intermetallic compounds and ternary systems, which is critical for understanding and controlling their physicochemical properties. When melting a complex alloy, the content of leboite (Fe₃Si₇) in the Fe-Si-Mn-Al system plays a significant role. The development of melting process technology will be aimed at avoiding the FeSi₂-Fe₃Si₇-F₂(FeAl₃Si₂)-Mn₁₁Si₁₉ tetrahedron area. This approach to controlling the composition of a complex alloy is critical to ensuring its consistent friability properties in industrial applications. Thus, this work represents an important step in understanding the physical properties and stability of Fe-Si-Mn-Al complex alloys, which have potential for widespread use in metallurgical and other industrial applications.

The research presented in the article is devoted to the study of the influence of phase compounds on the friability of the Fe-Si-Mn-Al complex alloy. The urgency of the problem lies in the development of technology for producing a non-scatterable alloy from manganese-containing ores and high-ash coals. The main goal of the work is to determine the range of alloy compositions and the resulting phases that affect the dispersibility of the alloy, which is critically important for its industrial implementation. Research methods include thermodynamic diagram analysis (TDA) using data on the standard enthalpy of formation of intermetallic compounds, as well as experimental tests in an ore-thermal electric furnace with a capacity of 200 kV*A. The results show that Fe-Si-Mn-Al complex alloys form a variety of silicide and aluminide phases, including intermetallic compounds and ternary systems, which is critical for understanding and controlling their physicochemical properties. When smelting a complex alloy, the content of leboite (Fe3Si7) in the Fe-Si-Mn-Al system plays a significant role. The development of smelting technology will be aimed at avoiding the FeSi2-Fe3Si7-F2(FeAl3Si2)-Mn11Si19 tetrahedron area. This approach to controlling the composition of a complex alloy is critical to ensuring its consistent friability properties in industrial applications. Thus, this work represents an important step in understanding the physical properties and stability of Fe-Si-Mn-Al complex alloys, which have potential for widespread use in metallurgical and other industrial applications.

This study investigates the behavior of phosphorus during high-temperature smelting of hydrogen-reduced high-phosphorus oolitic iron ore from the Lisakovsk deposit. The preliminary reduction was carried out at temperatures ranging from 600 to 900 °C using hydrogen, aiming to selectively reduce iron to the metallic phase while retaining phosphorus in the oxide form. The resulting reduced products were subjected to wet magnetic separation and liquid-phase separation. It was found that neither method provides effective separation of phosphorus from iron: phosphorus partially enters the magnetic fraction and, during smelting, transfers into the metallic phase. To confirm the mechanism of phosphate reduction by metallic iron, a control experiment was conducted, in which a mixture of reduced iron and raw ore was smelted at 1650 °C. Microstructural and elemental analyses confirmed the redistribution of phosphorus into the metallic phase. These findings indicate that effective separation of iron and phosphorus cannot be achieved by reduction roasting alone and highlight the need for further studies on slag formation conditions and phase separation kinetics.

Thermodynamic modeling combined with experimental reduction tests was conducted to investigate the selective reduction behavior of iron-manganese ore using hydrogen gas at 800–900 °C. The results reveal that hydrogen reduction at a flow rate of 0.5 L/min promotes the stepwise transformation of iron oxides (Fe₂O₃ → Fe₃O₄ → FeO → Fe), accompanied by the decomposition of the intermediate spinel phase Fe2MnO4, resulting in the formation of metallic iron. In contrast, the reduction of MnO to metallic manganese is thermodynamically unfavorable (ΔG > 0), limiting the extent of manganese reduction. Experimental findings confirm the formation of metallic iron inclusions enriched in Fe, while manganese predominantly remains in the form of MnO and silicate-associated oxides. X-ray diffraction analysis of reduced samples shows a decrease in Fe₃O₄ and Fe₂MnO₄ phases with increasing reduction degree and indicates the growth of metallic Fe particles with rising temperature. These results demonstrate that hydrogen enables controlled and selective reduction of iron with minimal manganese conversion, providing a promising route for subsequent efficient magnetic separation of metallic and oxide phases following reduction roasting.

This study evaluates the effects of semi-industrial and synthetic Fe–Si–Mn–Al deoxidizers on the microstructure, non-metallic inclusions, and hardness of St3 steel. Seven complex alloys with different Fe, Si, Mn, and Al contents were produced and compared with conventional FeSi–FeMn–Al deoxidizers. The steel samples were examined by optical microscopy and Rockwell hardness testing. Depending on the deoxidizer composition, ferrite–pearlite, bainitic, martensitic, and structurally heterogeneous regions were observed. The measured hardness ranged from 26 to 47 HRC. Porosity and dendritic heterogeneity remained in several samples. The results demonstrate that the composition of an Fe-Si-Mn-Al deoxidizer is associated with differences in optically observed microstructural characteristics and reported hardness. These findings provide an experimental basis for selecting complex deoxidizer compositions for further steelmaking studies.

Silica–carbon briquettes enable the incorporation of fine-grained silica-bearing materials and carbonaceous reductants into the charge used for ferrosilicon smelting. This study examines the composition of the composite disclosed in Patent of the Republic of Kazakh-stan No. 38264, the results of X-ray diffraction analysis of the briquette, and the chemical composition of ferrosilicon samples sequentially collected during the experimental smelting campaign. According to the patent data, the composite contained 41.41% fixed carbon, while the ash content was 39.38% on a dry basis, and the SiO₂ content in the mineral fraction was 90–92%. The first addition of briquettes was recorded at tapping No. 17. However, the exact timing of the corresponding metal sample collection relative to briquette charging is unknown; therefore, this sample was excluded from the comparison between the two operating periods. In samples Nos. 10–16, the Si content ranged from 74.75 to 76.21 wt.%, whereas in samples Nos. 18–24, it ranged from 75.49 to 76.47 wt.%. The corresponding arithmetic mean values were 75.65 and 75.77 wt.%, respectively. Analysis of the X-ray diffraction pattern of metal sample No. 20 allowed two iron–silicon phases to be tentatively identified. A silicon content of approximately 75 wt.% had already been achieved before the introduction of the briquettes. Owing to the sequential nature of the smelting campaign and the absence of a directly comparable material balance, the independent effect of the briquettes on alloy composition, silicon recovery, or electrical energy consumption cannot be reliably established.