Rudomain Iron Ore Treatment by High-Temperature Reduction

Abstract

The purpose of this study was to conduct experiments comprising the high-temperature reduction treatment of commercially produced iron ore fines and lumps aimed at increasing the use value of the ore. The analysed ore was Ukrainian iron ore sold under the Rudomain commercial name, mined from a bed located in the southern part of the Saksagan region (Kryvyi Rih, Ukraine). The study describes in detail the basic physical, chemical, and physico-chemical properties of the analysed ore, and it comprised a thermodynamic analysis, which is typically used as the basis for defining reduction conditions. The Ukrainian ore—Rudomain—exhibited a lower total Fe content (58.20 wt%) and, by contrast, the highest SiO2 content (13.40 wt%), whereas SiO2 is present in this type of ore not only in form of silica (SiO2) but also in form of hydrated iron silicate (Fe3Si2O5(OH)4), i.e., the form of iron that is the most difficult to reduce. In the study, tests of thermal stability and thermal shock stability were carried out in various conditions, while the hardened pellets were thermally stable up to temperatures of 950 °C. The results of the performed experiments in high-temperature reduction of Rudomain iron ore were then compared with the results obtained with two other types of iron ores, in particular Krivbas and Carajas. Krivbas and Carajas ores show higher degrees of reduction and degrees of metallization than Rudomain ore. High-temperature experiments in thermal stability and carbothermic reduction have brought favourable information that is useful for the treatment of lower-grade ores with higher contents of SiO2, while Rudomain iron ore exhibited a rather good potential for effective metallisation.