Production Technology of Iron Ore Sinter With Low Slag Ratio

摘要

For the reduction of production cost of pig iron, POSCO is gradually increasing the rates of both pulverized coal injection and sinter burden into blast furnaces (BF). These processes require sinter burden with higher reducibility and lower slag ratio to keep the BF operation stable. In order to produce the sinter with low slag ratio, it is necessary to reduce the fluxes such as limestone, quartz and serpentine in the sinter raw mix. However, reduction of slag ratio generally results in poor qualities of sinter in terms of SI(shutter index0 and PDI(reduction degradation index). Furthermore, raw materials for sintering are significantly changing into the adverse situations such as ncreasing uses of goethite and anthracite for the reduction of sinter production cost and these trends are expected to cintinue even in the near future. Some fundamental experiments and pot tests have been made in the laboratory to prevent the quality deterioration of sinter, which results from the reduction of fluxes and increase of goethite ratio in iron ore sintering. Some of results are described in this paper.