Phase formation in iron ore sintering

Abstract

During the iron ore sintering process, iron ore fines (<6 mm) are mixed with limestone flux and coke breeze and heated to ~1300&#0186;C. This results in partial melting of the mixture, and converts the loose raw materials into a porous but physically strong composite material in which the iron bearing minerals are bonded together by a range of complex ferrite-like phases known collectively by the acronym 'SFCA' (Silico-Ferrite of Calcium and Aluminium). These 'SFCA' phases can be divided on the basis of composition and morphology into two main types: one is a low-Fe form that is simply referred to as SFCA, and the second is a high-Fe, low-Si form called SFCA-1. SFCA and SFCA-1 are believed to be the most desirable bonding phases in iron ore sinter because of their high reducibility, high mechanical strength and low reduction degradation, all of which are significant factors in determining the efficiency of the blast furnace