研究焦炭反应性对块矿在高炉中的熔滴性能和滴落物质量等冶金性能的影响,可全面解析不同反应性的焦炭在高炉内的实际劣化情况,为完善焦炭综合评价指标体系提供技术支撑。通过铁矿石荷重还原滴落性能实验检测装置,在CO2/N2体积分数比为30%∶70%条件下,研究5种不同热态反应性的焦炭以及混装焦炭对高炉操作和滴落物质量的影响。研究结果表明:焦炭反应性从22.0%升至50.2%,软化温度逐渐减小,软熔带增厚;当焦炭反应性小于35%时,随着反应性的增加则压差陡升温度降低、透气性变差,同时滴落物中会逐渐出现难还原的Fe2SiO4和未彻底还原的FeO,滴落物中焦粉含量也逐渐增加;当焦炭反应性大于35%时,随着反应性的增加则压差陡升温度升高,透气性得到改善,难还原的Fe2SiO4和未彻底还原的FeO逐渐减少,滴落物中焦粉含量也逐渐减少。按一定比例搭配的混装焦炭在减小软熔带厚度、改善透气性、减少滴落物中焦粉含量等方面优于单一热态性质的焦炭。

The influence of cokes’ reactivity on metallurgical properties (e. g., droplet properties and dripping mate⁃rial quality of lump ores) was studied to discuss the actual deterioration of cokes with different reactivity in the blastfurnace. It provided technical support for improving the comprehensive evaluation index system of cokes. The experimen⁃tal testing device was applied for the dripping performance of iron⁃ore load reduction. When the CO2 / N2 volume fractionratio was 30% ∶ 70%, the influences of five different thermal reactivity cokes and mixed cokes on blast furnace opera⁃tion and dripping material quality were investigated. The results show that: when cokes’ reactivity rose from 22. 0% to50. 2%, the softening temperature gradually decreased and the soft melt zone thickened. When the reactivity of coke wasless than 35%, as the reactivity increased, the pressure difference sharply increased and the temperature decreased,breathability was reduced, at the same time, difficult⁃to⁃reduce Fe2SiO4 and incompletely reduced FeO gradually ap⁃peared in droppings, and coke powders in droppings gradually increased. When the reactivity of coke exceeded 35%,the pressure difference and temperature rose with permeability improved. Breathability was improved, difficult⁃to⁃reduceFe2SiO4 and incompletely reduced FeO gradually decreased, and coke powders in droppings also gradually decreased.Cokes mixed in a certain proportion were superior to those with a single thermal property in reducing the thickness of thesoft melt zone, improving air permeability, and reducing the concentration of coke powders in drippings.