摘要
Silicon is one of the main gangue components in iron ore,usually in the form of quartz and olivine.Numerous studies have shown that SiO_(2) has a two-sided effect on the consolidation of pellets during high-temperature oxidation roasting of magnetite.However,it is very difficult to capture the structural evolution and migration mechanisms during high-tem-perature roasting process by existing experimental methods.Therefore,the influence of SiO_(2) on the consolidation behavior of magnetite was studied through a series of roasting experiments and molecular dynamic simulation.The results show that the consolidation index and particle growth index decrease with the increase in SiO_(2) content in the particles.At 1573 K,the liquid phase promotes the recrystallization growth of hematite at high temperature.Molecular dynamic study shows that it is difficult for quartz SiO_(2) to form sintering neck with Fe_(2)O_(3).When the calcination temperature is higher than 1400 K,the Fe_(2)O_(3)-Fe_(2)SiO_(4) system produces a considerable sintering neck structure after relaxation.The atomic migration ability of Fe_(2)SiO_(4) is much higher than that of Fe_(2)O_(3).The higher atomic migration ability of Fe_(2)SiO_(4) is the main reason for the formation of the sintering neck.
基金
The authors would like to thank the National Natural Science Foundation of China(52204335)for its financial assistance.
