摘要
不同的钒钛磁铁矿通常表现出不同的烧结性能,其本质原因是成矿行为不同.本研究基于铁矿烧结不完全熔融的特性提出了一种新的钒钛磁铁矿烧结成矿模式,将烧结矿结构划分为骨架料与液相两部分,其中液相是影响烧结矿性能的关键.基于该模式,通过热力学分析比较了不同钒钛磁铁矿的液相生成及其物相变化,查明了在固定碱度下,液相中SiO2和TiO2含量差异是不同钒钛磁铁矿成矿行为不同的主要原因;钒钛磁铁矿中SiO2含量高,烧结液相量高;钒钛磁铁矿中TiO2含量高,钙钛矿生成量高,有效的CaO含量少,液相量少;当液相中SiO2与TiO2的含量同时增加,且其增量比值>0.5时,可避免TiO2对烧结矿液相产生的不利影响.对不同类型的钒钛磁铁矿进行相互替代的烧结杯试验,结果表明,钒钛磁铁矿的烧结性能与新模式下的成矿行为具有良好的相关性,随着钒钛矿中TiO2含量的提高,液相量减少,烧结矿强度降低,液相中铁酸钙减少,次生赤铁矿增加,还原粉化性能下降.但当使用TiO2和SiO2含量分别为7.99%和3.86%的钛铁矿取代TiO2和SiO2含量为4.30%和2.12%的钛铁矿时,低温还原粉化指数下降幅度小于4%,烧结矿强度增加了1.60%,成品率提高了2.56%.
Abstract
Different vanadiferous titanomagnetites commonly show different sintering performance and the underlying reason is the difference in mineralization behavior.In this work,a mineralization mode for vanadiferous titanomagnetites sintering was developed and mineralization behavior for vanadiferous titanomagnetites was compared by thermodynamic analyses.Besides,the sintering performance was clarified by substitution for each other.The results indicate that sintering performance shows an excellent correlation with mineralization behavior in the novel mineralization mode.The difference in mineralization behavior and sintering performance of vanadiferous titanomagnetites was attributed to the discrepancies in TiO2 and SiO2 content,and a higher SiO2 content was able to offset the negative impact of TiO2 at a fixed basicity.As the TiO2 content in titanomagnetite increased from 1.53%to 4.30%with a similar SiO2 content,the liquid phase amount,mechanical strength,calcium ferrite in the liquid phase,and reduction disintegration performance of sinter decreased significantly.However,when ilmenite with TiO2 and SiO2 contents of 7.99%and 3.86%was used to replace ilmenite with TiO2 and SiO2 contents of 4.30%and 2.12%,the reduction disintegration index decreased by less than 4%.The strength of sinter increased by 1.60%,and the yield increased by 2.56%.
基金项目
National Natural Science Foundation of China(52274290)
National Natural Science Foundation of China(72088101)
Hunan Provincial Natural Science Foundation,China(2021JJ40776)
NETL
NSTL
维普
万方数据