The Influence Of The Mineral Composition And Microstructure On The Quality Of The Low Silicon Sinter

The sintering materials become into the sinter by the way of pre-disposing, crashing, grinding, mixing, pelleting, sintering and other technics process. On one hand, the technics conditions of the production must have an important influence on the mineral phase composition and microstructure, on the other hand, the mineral phase composition and microstructure decides the performance of the sinters. So the research of the mineral phase composition and microstructure and the mastery of the change character can help us to estimate the performance and quality of the sinters, understand the relationship between the mineral phase composition and microstructure and the macro performance, all of this will help us to improve the quality of the sinters. The low silicon sinters have many advantages, but they also have amount of disadvantages, such as the lower intensity and the inferior low temperature deoxidize pulverization performance, as a result, they can not be mass produced. At the same time, because the low silicon sinter is mostly sintered by the hematite powder, which is different from the traditional magnetite powder sintering, so we have to find a new approach to improve the quality of low silicon sinters.On the basic of the above tow points, this paper studies factors influencing the mineral phase composition and microstructure of low silicon sinters and technics conditions, by means of mass sintering experiments and microcosmic testing instruments, such as OM, SEM, and so on, finally adopts a series of sintering strengthen measures and improves the quality of sinters. At last, the quality of sinter whose silicon content is 4.0 percent amounts to the request of the blast-furnace smelt.This paper mainly includes the change law of the mineral phase composition and microstructure and the influence on the sinters quality at vary silicon contents; in the produce of the low silicon sinters, the change law of the mineral phase composition and microstructure and the influence on the sinters quality at vary basicity, MgO content and carbon content; the change law of the mineral phase composition and microstructure and the influence on the sinters quality at vary technics system. From the researches, an conclusion can drawn : If the process can produce much liquid phase during the sintering, and which can become into completely-crystal needle-shape or arborization ferrous calcium instead of glassiness, in the cooling process; if the ferrous phase is interweaved by the felt into the network instead of exiting in the insulation; if the mount of the pore is little, and uniformitly distributing, in addition, there are many close pores and few open pores; if the grain is little; if the mineral phase composition is simply and the microstructure is symmetrical, all of which will improve the quality of the sinters remarkably. In addition, this paper also draws an conclusion of the adequate technics parameter and system during the produce of low silicon sinters. The results of this research enriched the theories of iron ore agglomeration and may play an important role in production operation, process control and scientific research.