Importance of intensive mixing on sintering with fine-grained iron ore materials: characterization and function mechanism

Abstract

This investigation mainly focused on revealing the importance and function mechanism of intensive mixer on sintering performance with 100% fine-grained iron ore materials (the proportion of −0.074 mm exceeding 80%) through both lab-scale tests and statistic analyses. Results indicated that compared with conventional drum mixing, the intensive mixing reduced the proper moisture consumption considerably from 9.25% to 8.75%, while both the granulation effect and sinter product quality achieved a remarkable improvement. Intensive mixer realized the uniform dispersion of moisture, Ca(OH)2 and coarse nuclear particles (>0.5 mm), contributing to improving the utilization of moisture, and benefiting the granulation of fine iron ores through capillary force; the uniform dispersion of Ca(OH)2 benefited the growth of granules, and also improved the mechanical strength due to the binding effect of Ca(OH)2; the uniform dispersion of nuclear particles benefited forming granules mainly within the desirable size range of 3–8 mm. All these improvements optimized the bed permeability and mineralization process of raw materials during sintering process, which were the key factors to the improved sinter performance. The result findings are useful for guiding the application of intensive mixers in practical plants using high-proportion fine-grained iron ore materials.

Keywords

• Iron ore sintering
• Fine-grained iron ore materials
• Intensive mixer
• Function mechanism