Quantitative Investigation of MgO, Al2O3 and SiO2 Effects on Solid-State Formation of Secondary Hematite in Sintering Process of Iron Ore Fines

Secondary hematite (SH) is a serious factor resulting in reduction degradation of iron ore sinter blast furnace; however, until now, quantitative study for SH formation had not been reported. In this work, the effects gangue composition, including MgO, Al2O3 and SiO2, on solid-state sintering process fines were investigated quantitatively. It shows that decreased from 67.84% to 46.11%, 35.44% 22.37% after adding 1.0%, 3.0% 5.0% respectively, while Al2O3, amount increased 69.38%, 69.98% 70.56%, respectively. For changed 68.14%, 61.59% 47.96%, Simultaneously, magnetite (magnesioferrite) 8.24% 34.79%, 50.26% 70.45% 8.95%, 8.37%, 7.62% 7.62%, 11.10%, 18.77%, compared with no gangue. This indicates decrease magnesioferrite. was found relates diffusion Mg2+ magnesioferrite, which inhibits kinetically. A supposition suggested maghemite existed at high temperature, an increase MgO addition. would be another reason improve performance sinter.