Microstructure and Reduction Properties of Sinter Agglomerates by Two Separate Granules with CaO

As a means of improving sinter qualities, various granulation methods have been studied. This report presents the minerals formation during heating in "the separated granulation method" and its effect on reduction properties of sintered body. Tests were carried out with specimens which consisted of two types of pseudo-particles : one contained high CaO content and the other low CaO content. The particles were mixed and sintered together in a electric furnace. Then reduction degradation, reducibility, strength, and microstructure were examined on the sintered specimens. The results showed that CaO segregation in raw materials by the separated granulation improved RDI without worsening of reducibility. The RDI improvement was considered to depend on decrease in secondary hematite and in co-existence area of secondary hematite and calcium ferrite.