高铬型钒钛磁铁矿煤基直接还原研究

将高铬型钒钛磁铁精矿、还原剂煤粉和黏结剂按一定比例配料、混匀、模压成型后进行直接还原,研究了煤种、碳氧摩尔比(COR)、还原温度、还原时间和添加剂等因素对高铬型钒钛磁铁精矿还原产物金属化率的影响,采用X射线衍射对还原产物进行物相分析.结果表明:以无烟煤为还原剂,碳氧摩尔比1.2、还原温度1 350℃、还原时间60 min的条件下,未采用添加剂时产物金属化率最高可达89.80%;在碳氧摩尔比1.2、还原温度1 250℃、保温时间30 min、添加质量分数为3%Ca F2条件下,还原产物金属化率达85.27%,有效降低了还原过程的能耗.还原温度低于1 250℃时,产物主要物相为金属铁,同时还有少量的Fe2O3,Fe3O4,Fe3C,Fe0.5M g0.5Ti2O5和Ti O2;1 300℃时,还原产物中出现Fe2VO4;高于1 350℃时,还原产物中出现了(Fe,Cr)和Ti3O5.

Study on Coal-Based Direct Reduction of High-Chromium Vanadium-Titanium Magnetite

High-chromium vanadium-titanium magnetite， reductant coal and binder were mixed and pressed into pellets， and then direct reduction of the pellets was conducted. The effects of coal types， COR， reduction temperature， reduction time and additive on the metallization rate of the reduction products were studied. The minerals of the reduction products were analyzed by X-ray diffraction. The results showed that， under the condition of anthracite， COR of 1.2， temperature of 1350℃， and reaction time of 60min， the maximum metallization rate is 89.80% without any additive. Under the condition of COR of 1.2， temperature of 1250℃， and reaction time of 30min， the maximum metallization rate is 85.27% with 3% CaF₂ addition， showing that the energy consumption of the reduction process can be reduced. When the reduction temperature is lower than 1250℃， the main mineral of the product is metallic iron， and the others are small amounts of Fe₂O₃， Fe₃O₄， Fe₃C， Fe_0.5Mg_0.5Ti₂O₅ and TiO₂. When the temperature is 1300℃， Fe₂VO₄ appeared in the reduction products. When the temperature is 1350℃， (Fe， Cr) and Ti₃O₅ appeared in the reduction products.