Comparison of reduction disintegration characteristics of TiO₂-rich burdens prepared with sintering process and composite agglomeration process

To reveal the impact of the composite agglomeration process (CAP) on the reduction disintegration properties of TiO₂-rich ironmaking burden for a blast furnace, the reduction disintegration indices (RDIs), mineral constituents, and microstructure of the products prepared by the CAP and the traditional sintering process (TSP) were investigated. The results showed that, compared to the sinter with a basicity of 2.0 prepared by the TSP, the RDI_+6.3 and the RDI_+3.15 of the CAP product with the same basicity increased by 28.2wt% and 13.7wt%, respectively, whereas the RDI_-0.5 decreased by 2.7wt%. The analysis of the mineral constituents and microstructure of the products indicated that the decreasing titanohematite content decreased the volume expansion during reduction. Meanwhile, the decreasing perovskite content decreased its detrimental effect on the reduction disintegration properties. In addition, the higher silicoferrite of calcium and aluminum (SFCA) content improved the strength of the CAP product. Together, these factors result in an improvement of the RDI of the CAP products. In addition, compared to the sinter, the reduced CAP products clearly contained fewer cracks, which also led to mitigation of reduction disintegration.