高配比镜铁矿粉混合料烧结性能改善

Improvement of sintering performance of sinter mixtures containing high ratio of specularite fines

镜铁矿铁品位高、杂质含量低,是优质炼铁原料,但其制粒性能差,导致透气性差,烧结矿产量和质量下降,因此在烧结生产中的配比（质量分数）一般不超过20%。为了增加镜铁矿在烧结生产中的使用比例,使用烧结杯实验对添加粘结剂改善高配比镜铁矿粉混合料烧结性能进行了研究。结果表明,在镜铁矿粉配比为36%时,添加质量分数为0.65%的膨润土或0.55%的BF复合粘结剂,可使烧结混合料层冷态透气性指数分别提高19.05%和27.98%,热态透气性分别提高21.48%和18.19%,烧结机利用系数分别提高11.67%和7.50%;固体燃耗则分别降低2.82和4.01 kg/t。烧结矿转鼓强度、化学成分和冶金性能均满足高炉冶炼要求。因此,2种粘结剂均能显著改善高配比镜铁矿粉混合料制粒及烧结性能,是提高镜铁矿粉配比的有效措施之一。

Although specularite fines possess high iron grade and low impurities,their granulation performance was poor so that the ratio of specularite fines is kept below 20% in sinter ore blends because of low permeability and productivity and weak strength. In order to increase its ratio in sintering,binders were used to improve the granulation performance of sinter blends containing high ratio of specularite fines in sintering pot test. Results show that cold permeability of the sintering bed increases by 19. 05% by adding 0. 65 mass% bentonite or by 27. 98% by 0. 55 mass% BF composite binder respectively when 36 mass% specularite fines are proportioned in sinter blends. In addition,the hot permeability is also improved by adding bentonite or BF composite binder,respectively,resulting in an increase in the productivity of11. 67% and 7. 50% as well as an decrease in solid fuel consumption of 2. 82 kg/t and 4. 01 kg/t,respectively,while the tumble index,chemical composition and metallurgical performance meet the requirement of blast furnace. So using suitable binders is one of effective ways to improve the granulation and sintering performance of sinter ore blends comprising high ratio of specularite fines.