INTERACTION BETWEEN LUMP ORE AND SINTER UNDER SIMULATED BLAST FURNACE CONDITIONS

摘要

Usually, the softening and melting (S&M) property of individual lump ore is thought to be inferior to iron ore sinter. However, it has been demonstrated that mixing -20% lump ore with high basicity sinter shows equivalent S&M behaviour to the sinter only burden, and potentially better behaviour than sinter with a lower basicity equivalent to that of the mixture. In this work, the high temperature interaction between sinter and Newman Blend Lump ore (NBLL) from Australia was studied from a physical and chemical point of view. The physical interaction was studied by a combination of optical microscopy on polished sections and neutron tomography on the entire crucibles from interrupted tests. The voidage in the ferrous layer of the mixed burden was found to be higher than that for either the sinter or NBLL only tests. The chemical interaction was studied using EPMA, which demonstrated that Ca and Mg diffused from the sinter to neighbouring lump ore particles during the S&M process. FactSage was used to assist in interpretation of the S&M test results. Both the physical burden structure and mineral composition were changed by the interaction between NBLL and sinter, and this resulted in a better S&M behaviour for the mixed burden.