Thermodynamic modelling of the metals’ reduction process from the Suroyam titanomagnetite concentrate

According to the P1 category, the forecast resources of the Suroyam ore deposit exceed 2.2 bn tones of titanomagnetite ore. This is an analog of the Kachkanarsk ore deposit in Sverdlovsk region. The major element in this ore is iron which content reaches about 16.5%. The other elements which are possible for extraction are titanium, vanadium and phosphorus. The processing of the concentrate is expected to be carried out by using the ITmk3 technology. In this paper the thermodynamic analysis was performed using the Terra software allowing estimation of the effect of temperature on parameters of processes occurring in the system metal-slag-gas. The effect of temperature on metal composition was analyzed. It was found that in the temperature range 500-800 °C the metal phase was comprised of iron, manganese, sulfur and carbon. With temperature increase to 800 °C and above vanadium, phosphorus, titanium and silicon were reduced to metal phase. The content of vanadium reached maximum at temperature 1100 °C, phosphorus at 1250 °C, whereas the content of titanium and silicon increased with the temperature enhancement. The effect of temperature on the composition of the slag phase was observed. It was found that in the temperature range 500-1100 °C the FeO content decreased from 65% to 0%. This led to an increase in the relative proportion of other oxides ((SiO2, Al2O3, CaO, MgO and etc.). The proportion of P2O5 reached maximum at temperature 1000 °C, TiO2 - 1250 °C, SiO2 - 1350 °C, respectively. The coefficients of recovery of elements from the charge material to the metal were determined. It was found that with enhancement of temperature, the recovery ratio of iron, manganese, vanadium, phosphorus, titanium and silicon increased, whereas sulfur decreased. In the temperature range 1350-400 °C the coefficient of the extraction of iron, manganese, vanadium, phosphorus was 1, titanium 0.4-0.6, silicon 0.02-0.07 and sulfur 0.75-0.79.