Possibility of selective solid-phase reduction of iron from oolitic ore has been experimentally confirmed. Solid phase reduction was carried out at temperatures of 850 and 1000 °C in CO atmosphere and in the mixture with solid carbon. Distribution of iron and phosphorus was investigated with scanning electron microscope. It was found that at temperature of 1000 °C minimum amount of phosphorus (up to 0.3 %) is transformed into the metallic phase at reduction by carbon monoxide. Upon reduction in mixture of ore with carbon, phosphorus content in metal phase reaches 1.0 – 1.3 % evenat temperature of 850 °C. Thermodynamic modeling of the processes occurring during reductive roasting of oolitic ore was carried out depending on temperature (1000 – 1400 K) and amount of carbon in the system. It is shown that reduction temperature and degree of phosphorus reduction vary depending on ratio of CO and CO2 in the gas phase. At temperatures below 892 °C, phosphorus is not reduced and all iron is in metal phase. With an increase in amount of carbon in the system, phosphorus appears in metal phase. With an excess of carbon in the system, all phosphorus is in metal phase at temperature of 892 °С. Thus, with a certain amount of carbon in the system and, correspondingly, with a certain ratio of CO and CO2 in gas phase, selective reduction of iron is possible without phosphorus reduction even at temperature of 1100 °С. Comparison of experimental results with results of thermodynamic calculation confirms possibility of se selective reduction of iron without phosphorus reduction only by carbon monoxide.

The possibility of selective solid-phase reduction of iron from oolitic ore has been experimentally confirmed. Solid phase reduction was carried out at tem

The paper presents the results of studies of the composition of the oolitic iron ore of the Ayat deposit. Experiments were carried out and the results of the study of the decomposition of brown ironstone in the oxidizing atmosphere are presented. Analysis of the chemical composition of the initial and burnt ore was carried out using an electron microscope (micro X-ray spectral analysis), and also by the chemical method. The study of the mineralogical composition of the initial and burnt ore was carried out on a diffractometer by X-ray diffraction analysis. The obtained data are necessary for the development of theoretical and technological bases of pyrometallurgical processing of oolitic iron ores with high phosphorus...

Selective solid-phase reduction of iron and phosphorus in oolite ores of the Lisakovsky and Ayat deposits was experimentally studied. Using X-ray phase analysis, the phase composition of the initial ores and samples after reduction roasting was determined. Goethite, magnetite and quartz were found in the ores of both deposits. Phosphorus in the ore of the Ayat deposit is in the form of aluminum phosphate and iron hydrophosphate, and in the samples of the Lisakovsky ore – as a component of calcium hydrophosphate. Experiments on reduction roasting were carried out in a resistance furnace at 1000 °C with holding time of 5 h. After roasting in CO atmosphere, α-Fe appears in the samples, while phosphorus remains as a component of iron, calcium and aluminum phosphates. After roasting in a mixture with graphite, phosphorus is reduced by solid carbon from iron and calcium phosphates and passes into metal, but remains as a component of aluminum phosphate. Studies using microroentgenospectral analysis show that phosphorus content in the metal phase after reduction with solid carbon is 2.0 – 3.5 at. %. When CO is reduced in the atmosphere, phosphorus in the metallic phase is practically not detected. At the same time, the amount of residual iron in the oxide phase after carbon monoxide reduction significantly exceeds the amount of iron after reduction in a mixture with carbon. The experimental results confirm the possibility of selec­tive reduction of iron by carbon oxide CO without phosphorus reduction.

This study investigates the thermodynamic and technological aspects of smelting medium-carbon ferromanganese from Zhezdinsky manganese ore using ferrosilicomanganese and lime. The equilibrium distribution of components in the oxide-metal system was calculated using HSC Chemistry 10.0 within the temperature range of 573–2073 K. The modeling results revealed the effect of lime and ore consumption on slag phase composition as well as on manganese and silicon contents in the metallic phase. Experimental validation was performed in a laboratory Tamman resistance furnace and in a 100 kVA large-scale laboratory electric arc furnace. The chemical compositions of metal and slag were determined by bulk chemical analysis, while microstructure and local elemental distribution were examined using SEM-EDS. An increase in slag basicity was found to promote the transfer of silicon into the silicate phase while simultaneously reducing manganese losses to the slag. The large-scale laboratory smelting experiments, with a duration of 100–120 min per heat, enabled the establishment of a stable processing regime and the production of a metal with an average composition of 88.1 wt.% Mn, 1.6 wt.% C, and 0.03 wt.% Si. The corresponding slag contained approximately 15 wt.% MnO and 21 wt.% SiO₂. SEM-EDS analysis showed that the alloy possesses a heterogeneous microstructure consisting of an Fe-Mn metallic matrix with finely dispersed silicide microphases. Local silicon concentrations in these phases reach 15–24 wt.%, which explains the discrepancy between local and bulk chemical compositions. The experimental data are in good quantitative agreement with the thermodynamic modeling results, confirming that slag basicity and composition control are key factors for improving manganese recovery and stabilizing metal composition. The identified relationships can be applied in the development of industrially oriented smelting regimes for producing medium-carbon ferromanganese from Kazakhstan manganese raw materials.