Abstract
To control the melting reaction in sintering process by the fine part selective granulation of clayish iron ores, some studies consisted of tablet firing tests, sintering pot tests and an operation test at a commercial sintering machine were carried out. On the basis of these tests, the melting property of the bond-forming part which form the melt for coalescing pseudo-particles, and the heat supply for the melting were investigated.
It was clarified that the melting property of the bond-forming part can be determined by the tablet's deforming temperature related to CaO and Al2O3 content. Optimum heat supply value corresponding to the melting property of the bond-forming part was recognized for the strength of sinter (SI). As a result, the contour line of SI could be described on the two-dimensional map consisted of the melting property and the heat supply. Furthermore, it was possible to control the operational point on that map by the fine part selective granulation of clayish iron ores.
From the result of the operation test at a commercial sintering machine, the green pseudo-particles of clayish iron ores by selective granulation was strong enough to retain the segregation of chemical composition and heat source in the raw mix after handling. Also, the increase in melt formation of the sinter products was confirmed by the increase in open pore ratio and pore size. Finally, coke consumption, permeability and reducibility of sinter were significantly improved by the fine part selective granulation of clayish iron ores.
