Study On Sinter Microstructure With Addition Of FMG Fines

On the base of Wisco sintering production, several sinter pot experiments with varyingproportions of FMG ifnes and fuels ratio were conducted in the lab. The mineralogicaldistribution, characteristic, composition and the micro mechanical property of all the resultingsinters in different parts of sinter pot were tested by optical microscope, microhardness testerand electron microscope.The results got from the sinter pot trails are as follows. Firstly, the tumbler strength ofsinter declines as the proportion of FMG ifnes increases from0to40percent. Secondly, thesinter time and production rate are reduced as the proportion of FMG ifnes is raised. Thirdly，as the fuel ratio increases from5.5%to7.0%，the tumbler strength of sinter increases at ifrstand then decreases. Lastly, we found that the obvious fuel segregation in different parts ofsinter pot leads to the content of FeO and some other chemical compositions in sinterlfuctuating.The microscopic research of sinter shows that as the proportion of FMG ifnes increases,the microhardness of the sinter mineral phases decreases, so the number of cracks increasesand the ore becomes brittler; the content of hematite and magnetite declines while the numberof large pores and calcium ferrite increases, and there are more penetrative cracks across thesinter. As the tfiel ratio increases, the content and the microhardness of hematite and calciumferrite declines while magnetite increase, the number of pores decrease, the number of all thesinter mineral phases decrease and there are more penetrative cracks across the sinter. Micromechanical properties of sinter of the lower part is better than upper part, the micromechanical properties changed less as the proportions of FMG ifnes and fuels changed.In conclusion, this article presents speciifc approach to improve the tumbler strength ofsinter. Considering the changes of microstructure and tubler strength of sinters，It is advisedthat the proportions of FMG ifnes should be lower than30%and the fuel ratio should belower than6.5%.