The current intensive development of steelmaking is being impeded by a scarcity of pure scrap. The potential to replace pure scrap with metallized raw materials that are naturally alloyed with vanadium and titanium, such as annealed unfluxed titanomagnetite pellets, could facilitate the achievement of key objectives in metallurgical development, particularly in the smelting of electric steel. The objective of this research was to produce annealed and metallized pellets from titanomagnetite concentrate under laboratory conditions, with the intention of further processing them as a commercial product in a blast furnace or as an intermediate product for the production of hot briquetted iron (HBI). The results demonstrate that pellets derived from titanomagnetite concentrate exhibit sufficient compressive strength (up to 300 kg/pellet) and a degree of metallization exceeding 90%, which aligns with the requirements for electric steelmaking. The suitability of pellets derived from titanomagnetite concentrate for use in both blast furnaces and metallization processes has been corroborated.

The paper considers the effect of introducing ferroalloys containing titanium and zirconium on the structure and heat-resistance of low-carbon ferroalloys.

The present study explores the production of metallized titanomagnetite briquettes, with a view to addressing two key issues. Firstly, it seeks to address the growing shortage of high-quality iron-bearing raw materials. Secondly, it looks at how to meet the increasingly stringent environmental constraints. The conventional blast-furnace treatment of titanomagnetite is hindered by the formation of refractory Ti-rich slags. It is hereby proposed that a single-cycle briquetting process in conjunction with a thermal reduction route should be utilized. This approach enables precise regulation of the Fe/flux ratio. Experiments were conducted on a low-grade titanomagnetite concentrate (68.5% Fe) from the Pervouralsk deposit (Russia). Cylindrical briquettes (D 15–20 mm, h 8–10 mm) were subjected to a pressure of 300 MPa during the pressing process, with the utilization of diverse binders comprising rubber cement, CaO, graphite + water, and basic oxygen-furnace (BOF) slag + sodium silicate. Following an oxidative pre-heating process at 1300 °C for two hours, followed by a gas-based reduction process at 1050 °C for three hours, with a CO/N₂ ratio of 90/10, the products demonstrated an oxidation rate of 85–95% and a cold compression strength of 16–80 MPa. The highest observed strength (80 MPa) was obtained with a binder comprising CaO·MgO·2SiO₂ (diopside/merwinite), which forms a low-viscosity melt, fills 90% of pores and crystallizes as acicular Mg-SFCA-I during cooling. Conversely, the CaO·TiO₂ and FeO·TiO₂ + Fe₃C associations yield brittle structures and a maximum strength of 16 MPa. The optimum briquette (0.55% CaO, D/H = 20/10 mm) exhibited a 95.7% metallization degree, a compressive strength of 48.9 MPa, and dimensional changes within acceptable limits, thus fulfilling the requirements for electric arc furnace feedstock. Further research is required in the form of a full Life Cycle Assessment and pilot-scale testing. However, the results obtained thus far confirm that titanomagnetite briquettes with a binder consisting of CaO, MgO and SiO₂ are a promising alternative to pellets for low-carbon steelmaking.

The cohesion zone of a blast furnace is instrumental in determining the gas-dynamic regime and the efficiency of reducing gas utilization. The extent of this phenomenon is contingent upon the initial and final temperatures at which iron ore undergoes softening, which, in turn, are determined by the chemical and phase composition, as well as the degree of reduction of the charge. The present study investigated sinter with a basicity (CaO/SiO₂) ranging from 1.2 to 3.0 using a combination of methods. The experimental program involved the use of X-ray diffraction (XRD) with refinement using the Rietveld method, scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDS), and load-dependent softening tests. It was established that as the basicity increased, the content of the calcium–aluminum silicoferrite (SFCA) binder phase increased from 6.2 to 17.5 wt.%, whilst the amount of hematite decreased from 12.6 to 2.3 wt.%. The softening onset temperature increases from 1185 to 1260 °C, the softening end temperature from 1345 to 1415 °C, and the softening interval narrows from 160 to 155 °C. The evolution of the phase composition of sinter during controlled reduction (0–95%) has been investigated for the first time. It has been demonstrated that the maximum accumulation of wustite (FeO) is attained at a reduction degree of 40–60%, irrespective of the basicity of the substance. It is precisely in this range that the minimum softening start (1040–1065 °C) and end (1170–1210 °C) temperatures are observed, which is associated with the formation of low-melting eutectics. The sinter belongs to the CaO–SiO₂–FeO–Al₂O₃–MgO system, and the softening behavior is governed by the FeO–CaO–SiO₂ system where low-melting eutectics form. When the reduction rate exceeds 60%, the metallic phase becomes dominant, leading to an increase in softening temperatures and a narrowing of the cohesion zone. It is evident from the data obtained that the optimal basicity range of the sinter is 2.0–2.5. Furthermore, it is recommended that a reduction degree of at least 60% is implemented in order to improve gas dynamics and increase blast furnace productivity. The findings can be utilized to enhance the efficiency of charge materials and refine mathematical models of the blast furnace process.