Along with the growth in the production of metallurgical grade silicon and high-silicon ferrous alloys, there is a significant increase in the formation of microsilica, which is an ultra-fine technogenic waste. The direct application of microsilica in ore-thermal furnaces is hindered by low bulk density, poor gas permeability, and high dusting. This paper explores the thermophysical and microstructure properties of briquettes based on microsilica, which includes various types of carbonaceous reducing agents such as semi-coke and coal. For manufacturing, the liquid glass was used as the inorganic binder for the preparation of microsilica briquettes. The best variants were chosen based on strength tests carried out during preliminary studies. In the laboratory tests, the stability of the briquettes at elevated temperatures was evaluated. Samples were heated to 1000–1500 °C and subjected to impact testing. Scanning Electron Microscopy with Energy Dispersive Spectroscopy (SEM/EDS) was used to investigate the microstructure and local elemental distribution. It was revealed that the calcinated briquettes of the microsilica–semi-coke mixture have better thermal stability compared to the samples with coal and withstand the temperature range up to 1500 °C. The microstructure of the briquette from the microsilica-semi-coke mixture is characterized by the formation of a more uniform silicate matrix with the presence of a homogeneously distributed carbonaceous component. Coal-based samples show higher heterogeneity and porosity. Therefore, it can be stated that the selection of carbonaceous reductants is one of the key factors influencing the thermal stability of microsilica briquettes.

This article presents data on the production and trade turnover of silicomanganese (SiMn) in the world and Kazakhstan. Based on these studies, it is possible to predict the future state of silicomanganese. The global silicomanganese market is expected to grow from $25.98 billion in 2022 to $28.33 billion in 2023 at a cumulative annual growth rate (CAGR) of 9%. The Russian-Ukrainian war has undermined the chances of a global economic recovery after the Covid-19 pandemic, at least in the short term. The war between the two countries led to economic sanctions against many countries, rising commodity prices and supply chain disruptions, which caused inflation of goods and services and affected many markets around the world. The global silicomanganese market is expected to reach $38.35 billion in 2027 with an average annual growth rate of 7.9%. It is expected that the growing demand for steel products will contribute to the further growth of the silicomanganese market. Steel products are products that are made from iron and metal in factories by various methods and mixed with alloys such as carbon, zinc and others. Silicomanganese is used to produce various types of steel for various purposes, such as carbon steel, alloy steel, manganese steel. Such use leads to an increase in demand for silicomanganese in the production of steel products. For example, in 2022, according to the World Steel Association (WSA), the Belgian international trade organization for Ferrous Metallurgy, steel consumption will increase by 0.4% in 2022, reaching 1.840 million tons. Steel consumption will increase by 2.2% in 2023, reaching 1.881 million tons. Thus, the growing demand for steel products stimulates the silicomanganese market.

This study investigates the utilization of high-ash coal as an alternative reductant in the smelting of silicomanganese, aiming to reduce the carbon footprint of traditional coke-based processes. Experiments were conducted using an ore-thermal furnace with a transformer power of 200 kVA to simulate industrial conditions. The charge consisted of manganese ore (Mn - 36%), slag from refined ferromanganese production (MnO - 25%), and high-ash coal (ash content 40%–50%). Chemical analysis of the produced alloy showed a composition of Mn–70%, Si–20%, C–1.28%, P–0.06%, and S–0.05%, meeting the standards for silicomanganese. The results demonstrate that high-ash coal can replace coke without compromising the quality of the alloy. This approach not only indirect CO₂ emissions but also leverages the abundant availability of high-ash coal, which is often discarded as waste. The study highlights the potential for significant environmental benefits and cost savings, making this method a viable alternative for sustainable industrial practices. The findings support the industrial application of high-ash coal in silicomanganese production, contributing to more eco-friendly and economically feasible metallurgical processes.

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.

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.

The aim of this study was to investigate the effect of reduction roasting parameters on the phase transformations of the Ushkatyn-III ferruginous manganese ore and the efficiency of subsequent magnetic separation. The experimental procedure included preliminary high-intensity magnetic separation, reduction roasting at 650 °C for 3–5 h using 20–30 wt.% coal as the reducing agent, and low-intensity dry magnetic separation at magnetic field intensities of 0.1–0.6 T. Chemical composition was determined by standard analytical methods, while phase composition was analyzed by X-ray diffraction (XRD). Preliminary magnetic separation increased the manganese content in the magnetic pre-concentrate to 30.71–35.09 wt.%. The optimum results were obtained after roasting for 5 h with 30 wt.% coal, followed by magnetic separation at 0.2 T, producing a low-iron concentrate containing 33.26 wt.% Mn and 0.67 wt.% Fe, with a manganese recovery of 87.79% and an Mn/Fe ratio of 49.6. XRD analysis confirmed the partial reduction of hematite to magnetite (Fe₃O₄), providing the basis for efficient magnetic separation. The proposed process offers an effective approach for upgrading low-grade ferruginous manganese ores for manganese ferroalloy production.