Influence of MgO in form of magnesite on properties and mineralogy of high chromium, vanadium, titanium magnetite sinters

MgO in blast furnace slag provides an optimum condition in terms of both good flow ability and desulphurisation. The effect of MgO on blast furnace slag is fairly well established, but its effect on sintering and sinter quality is unclear especially on high chromium, vanadium, titanium magnetite (Cr-V-Ti magnetite) sinters. In the present study the effect of MgO, in the form of magnesite (MgCO 3 ), on sintering rate was calculated. Cr-V-Ti magnetite sinters with varying MgO content (1·95-3·01%) were tested for yield, strength and reduction degradation index. Productivity and comprehensive index were evaluated. Mineralogical microstructure and SEM-EDS analysis was done to measure the chemical analysis of oxide and slag phases, and XRD and XRD mapping was carried out to understand the interaction mechanism of MgO. From the results, it was observed that with increasing MgO, yield and TI initially increased then decreased with MgO addition, which is unfavourable for the formation of calcium ferrites but increases the silicate phases, and stabilises the crystal of magnetite in Cr-V-Ti magnetite Sinter. RDI was found to improve, productivity fluctuated, comprehensive index improved substantially in the range of 1·95-2·63%MgO but then decreased quickly. The studies revealed that most of the Mg 2+ was picked up by magnetite phase to form (Fe,Mg)O·Fe 2 O 3 and (Mg·Fe)O·Fe 2 O 3 .