Abstract
The formation mechanism of acicular calcium ferrite which is indispensable for improving the sinter quality was studied by use of a newly developed scanning electron microscope having a sintering furnace in it.
The in-situ observation results of the iron ore particle coated with CaO powder during heating and the microstructure of the sample quenched in sintering process showed that (1) small granular compounds similar to monocalcium ferrite are first generated on ore surface by solid state reaction and (2) immediately fuse to be a primary melt above 1 205°C, and then (3) acicular calcium ferrites are quickly formed by the interactive reaction between hematite in ore and high-CaO melt, absorbing a small amount of SiO2, Al2O3 etc. from the melt as solid solutions.
