Analysis of the Influence of the Degree of Reduction of Iron Ore Materials on the Shape and Location of the Cohesion Zone in a Blast Furnace

The paper considers the theoretical foundations of softening of iron ore materials in a blast furnace (the so-called ‘cohesion zone’). The dependences of the temperature range of softening of iron ore materials (the temperatures of the beginning and ending of softening) on the degree of reduction are calculated and experimentally obtained. Physical modelling of the softening process of reduced iron ore materials was carried out using the Russian State Standard No 26517-85. The results of calculations of the location and shape of the cohesion zone in the blast furnace for iron ore materials with different metallurgical characteristics are presented.

Green Synthesis of Iron Oxide Nanoparticle Using Coffee Seed Extract and Its Antibacterial Activity

The discovery of reliable and green processes for metal oxide nanoparticles synthesis is particularly crucial and exhibits huge potential in various applications. Thus, in this paper, a fast, single step and environmental-friendly method to synthesize iron oxide nanoparticles (Fe2O3-NPs) by bio-reduction of iron salts Fe2+ and Fe3+ under the presence of coffee seeds (CS) aqueous extract was demonstrated. The characteristics of the synthesised Fe2O3-NPs were investigated by using X-ray diffraction (XRD) and ultraviolet-visible (UV-Vis) spectrophotometry techniques. The XRD result revealed that the Fe2O3-NPs produced display highly crystalline property with a cubic structure and the average size of the resulted particle is ranging from 23.2 nm to 37.5 nm. Additionally, the energy band gap (Eg) calculated also showed that maghemite (γ-Fe2O3) nanoparticles was successfully synthesised by using CS extract. The resulted nanoparticles are highly feasible in the inhibition of the growth of pathogenic microorganism.

High Temperature Treatment of Selected Iron Rich Bauxite Ores to Produce Calcium Aluminate Slags

The Pedersen process is a method to produce alumina from Al-containing sources, and it is a more material-efficient method than the current commercial Bayer process, since the formation of bauxite residue (red mud) is avoided, and the bauxite can be holistically consumed. The smelting reduction (SR) part of the Pedersen process yields pig iron and a calcium aluminate slag, and the latter is a feedstock material for alumina extraction via alkaline leaching. In the present study, three different bauxite ores (Greek, Turkish and Jamaican) were smelted with lime to ease the process and control the slag chemistry and coke for the carbothermic reduction of iron oxides. The slags produced were analyzed with XRD, XRF, and EPMA to identify the phases and chemical compositions. According to the results, the slags composed of Al-containing leachable phases. Moreover, it is shown that the amount and distribution of both the leachable and non-leachable phases in the slags depend on the ore chemical composition. The results are discussed regarding the characteristics and potential leachability of the slags. Standard leaching tests were performed to examine the actual leachability.

Separation of ferromanganese ore components by non-contact and contact carbothermic reduction

The possibility of joint selective solid-phase reduction of iron and phosphorus in ferromanganese ore has been experimentally confirmed. The experiments were carried out in a Tamman laboratory furnace at a temperature of 1000 °C and holding for two and five hours. The article presents results of the study of phase composition and phases' quantitative ratio of the reduction products, as well as chemical composition of the phases. It was established that reduction roasting in CO atmosphere provides a transition from oxide phase to metal phase only of iron and phosphorus. At the same time, the concentration of manganese oxide MnO increases in the ore oxide phase. The use of solid carbon as a reducing agent under the same conditions leads to transition to the metallic phase together with iron and phosphorus of a part of manganese. Based on the obtained data, it is proposed to selectively reduce iron and phosphorus at a temperature of 1000 °C with a reducing gas. Gas reduction will make it possible to use existing gas furnaces, in particular, multi-pod furnaces, for metallization of iron and phosphorus in ferromanganese ore, and natural gas, including hydrogen -enriched gas, and even pure hydrogen, as a reducing agent and energy carrier. Due to this, at the stage of ore metallization in production of manganese alloys, greenhouse gas CO2 emissions can be reduced. The results of the work can be used in the development of theoretical and technological bases for processing ferromanganese ores with a high content of phosphorus, which are not processed by existing technologies.