强化高配比磁铁精粉制粒工艺研究

Research on Process of Enhancing Granulation Effectiveness of High-ratio Magnetite Concentrate Fines

研究针对某内陆型钢企烧结现场原料条件,以当地两种磁铁精粉A和B为主要原料,在实验室圆筒制粒机中研究了高配比磁铁精粉的制粒行为,并考察了原料预润湿、制粒水分、生石灰用量、粗矿粉和返矿比例等因素对制粒效果的影响。结果表明:在混匀矿中磁铁精粉配比高达90%及模拟现场制粒条件的情况下,制粒后混合料中+3mm含量仅为13.81%,透气性指数为14.1JPU。对原料进行预润湿能显著改善混合料的制粒性能,透气性指数提高至41.7 JPU;另外,提高制粒水分、延长制粒时间、提高生石灰用量及粗矿粉和返矿比例均有利于改善高配比磁铁精粉的制粒效率。

Sintering is an indispensable process for most steel mills to produce ferrous charge for blast furnace,and granulation is an important progress that greatly affects the output,quality and energy consumption of sinter.Especially for the sintering of high-proportion iron ore concentrates,enhancing its granulation effectiveness has always been one of the focal issues in research work.The study is based on the on-site raw material conditions of an inland stel mill.Two types of local magnetite concentrate fines A and B are used as the main raw materials,the granulation behavior of high-ratio magnetite concentrate fines is studied in a laboratory rotary drum.The influence of pre-wetting of sinter feeds,granulation moisture,proportion of quicklime,ratio of coarse fines and return fines are studied.The results show that when the ratio of magnetite concentrate fine in the mixed ore is as high as 90%and the on-site granulation conditions are simulated,the+3 mm fraction in the mixture after granulation is only 13.81%,resulting in poor permeability of 14.1JPU.Pre-wetting the raw materials can significantly improve the granulation performance of the mixture,leading to improved permeability of 41.7JPU.In addition,increasing granulating moisture,extending the granulation time,increasing the proportion of quicklime,ratio of coarse fines and return fines are all conducive to improvement in the granulation effectiveness.