高铬型钒钛铁精矿金属化球团的物化性能  

Physicochemical properties of metallized pellets of high-chromium vanadium-bearing titanomagnetite

作　　者：吴恩辉 李军 徐众 侯静 黄平 WU En-hui;LI Jun;XU Zhong;HOU Jing;HUANG Ping(College of Vanadium and Titanium,Panzhihua University,Panzhihua 617000,Sichuan,China;Vanadium and Titanium Resources Comprehensive Utilization Key Laboratory of Sichuan Province,Panzhihua 617000,Sichuan,China)

机构地区：[1]攀枝花学院钒钛学院,四川攀枝花617000 [2]钒钛资源综合利用四川省重点实验室,四川攀枝花617000

出　　处：《钢铁》2023年第2期30-38,共9页Iron and Steel

基　　金：四川省科技计划资助项目(2020YFH0195);攀枝花市科技计划资助项目(2021CY-G-4)。

摘　　要：高铬型钒钛铁精矿煤基直接还原-电炉熔分新工艺是实现铁、钒、钛和铬元素综合利用最有前景的非高炉冶炼工艺之一,而金属化球团的物化性能与后续电炉熔分工艺能否顺行密切相关。采用煤基直接还原工艺,研究了还原温度、还原时间、煤矿质量比和二元碱度对高铬型钒钛铁精矿金属化球团的物相组成、金属化率、残碳量、电阻率和抗压强度等物化性能的影响规律。试验结果表明,提高还原温度和延长还原时间均有利于磁铁矿和钛铁矿分别被还原为金属铁和黑钛石,而较高的煤矿质量比和二元碱度对还原过程不利;金属化球团电阻率的大小依赖于金属化球团的物相组成、不同物相组成的含量及各个物相之间的结合形式;金属化球团的金属化率与电阻率呈现较为明显的负相关,但是随着金属化率的提高,负相关的程度有所降低;在金属化率大于90%时,电阻率均小于0.5Ω/cm;金属铁的生成量和金属铁晶粒之间的连接作用是影响金属化球团抗压强度的关键因素,提高还原温度和延长还原时间有助于金属化球团抗压强度的提高,而随着煤矿质量比和二元碱度的提高,金属化球团的抗压强度降低。在还原温度为1300℃、还原时间为35 min、煤矿质量比为25∶100、二元碱度为0.13的条件下,金属化球团的金属化率、残碳量、电阻率和抗压强度分别为92.58%、5.39%、0.3Ω/cm和81.74 N/球。The iron,vanadium,titanium and chromium of high-chromium vanadium-bearing titanomagnetite can be comprehensively utilized by coal based direct reduction-electric furnace melting separation new process,which is one of the most promising non-blast furnace smelting processes.The physicochemical properties of high-chromium vanadium-bearing titanomagnetite metallized pellets have an important impact on the subsequent electric furnace melting and separation process.Based on this,the effects of reduction temperature,reduction time,coal-ore mass ratio and binary basicity on the physicochemical properties such as phase composition,metallization rate,carbon residue,resistivity and compressive strength of metallized pellets during coal based direct reduction were investigated.The magnetite and ilmenite were reduced to metallic iron and anosovite with increasing the reduction temperature and prolonging the reduction time,while higher coal-ore mass ratio and binary basicity have an adverse effect on the reduction process.The resistivity of the metallized pellets depends on the phase compositions,the content of different phase compositions and the combination form between each phase compositions of the metallized pellets.There was an obvious negative correlation between the metallization rate and resistivity of metallized pellets,while the degree of negative correlation decreased with the metallization rate increased.When the metallization rate was higher than 90%,the resistivity of metallized pellets was lower than 0.5Ω/cm.The formation content of metallic iron and the connection form between metallic iron grains were the key factors affecting the compressive strength of metallized pellets.The increase of reduction temperature and reduction time was favorable to improve the compressive strength of metallized pellets,while the compressive strength of metallized pellets decrease with increasing the coal-ore mass ratio and binary basicity.Under the condition of reduction temperature of 1300℃,reduction time of 35 min,coal-ore

关 键 词：钛磁铁矿 煤基直接还原 金属化球团 电阻率 抗压强度 

分 类 号：TF046.6[冶金工程—冶金物理化学]