The reduction rate and microstructural changes of imperial smelting furnace (ISF) sinter have been investigated by means of thermogravimetric analysis, X-ray diffraction (XRD), scanning electron microscope (SEM), ener...The reduction rate and microstructural changes of imperial smelting furnace (ISF) sinter have been investigated by means of thermogravimetric analysis, X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive analysis of X-ray (EDAX) and optical microscope. It is demonstrated that the overall reaction rate of the reduction is influenced by temperature and hydrogen partial pressure in H-2/N-2 gas mixtures. There are two distinct zones observed in the partially reduced sinter. The reduction of zincite proceeds predominantly in a narrow range between the two zones, while the reduction of lead oxide and silicate takes place throughout the sinter. The differences between zincite and lead oxide or silicate in reducibility are analysed by thermodynamics. The phase transformations and microstructural changes occurring during the reduction process are discussed.展开更多
文摘The reduction rate and microstructural changes of imperial smelting furnace (ISF) sinter have been investigated by means of thermogravimetric analysis, X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive analysis of X-ray (EDAX) and optical microscope. It is demonstrated that the overall reaction rate of the reduction is influenced by temperature and hydrogen partial pressure in H-2/N-2 gas mixtures. There are two distinct zones observed in the partially reduced sinter. The reduction of zincite proceeds predominantly in a narrow range between the two zones, while the reduction of lead oxide and silicate takes place throughout the sinter. The differences between zincite and lead oxide or silicate in reducibility are analysed by thermodynamics. The phase transformations and microstructural changes occurring during the reduction process are discussed.