含硼磁铁矿强化巴西赤铁矿球团的制备  

Improving pelletization of Brazilian hematite by adding boron-containing magnetite

作　　者：朱德庆[1] 周文涛[1] 潘建[1] 陈栋 

机构地区：[1]中南大学资源加工与生物工程学院,湖南长沙410083

出　　处：《中南大学学报（自然科学版）》2014年第2期348-355,共8页Journal of Central South University:Science and Technology

基　　金：国家科技部火炬计划项目(2011GH561685)

摘　　要：研究含硼磁铁矿配比对巴西赤铁矿球团生球质量、预热焙烧性能和成品球团冶金性能的影响。结果表明:配加30%和50%(质量分数)含硼磁铁矿后,生球的落下强度增加,爆裂温度显著提高;球团预热温度降低50℃左右,焙烧温度降低120℃以上;成品球团矿还原度从72.40%分别提高到87.95%和78.71%,低温还原粉化指数RDI+3.15从87.79%分别提高到97.38%和99.62%,还原膨胀率从36.25%分别降到12.50%和4.00%;焙烧性能得到提高的原因是Fe3O4氧化生成的新生Fe2O3晶体具有较大的活性,B2O3有利于含硼的镁铁橄榄石液相生成,这两者能够促进球团再结晶和晶粒长大;还原度提高的原因是B3+半径很小,易扩散进入Fe2O3晶格中,产生晶格畸变,使得Fe2O3易于还原;铁酸镁和含硼的镁铁橄榄石液相的生成,有利于还原膨胀和低温还原粉化性能的提高。The effects of adding ratio of boron-containing magnetite on Brazilian hematite green balls quality, preheating and roasting behaviors and metallurgical properties of product pellets were studied. The results show that the drop strength and thermal shock temperature of green balls increase, and the preheating and roasting temperatures of pellets decrease by about 50 ~C and 120 ~C respectively, by adding 30% and 50% （mass fraction） boron-containing magnetite. After adding 30% and 50% boron-containing magnetite, the reduction index （RI） of product pellets increases from 72.40% to 87.95% and 78.71%, the reduction degradation index （RDI＋3As） increases from 87.79% to 97.38% and 99.62%, and the reduction swelling index （RSI） decreases from 36.25% to 12.50% and 4.00%, respectively. The reason for improving the roasting behaviors is that the new Fe203 crystalloid from oxidation of magnetite is more active than original hematite, and B203 is beneficial to form liquid phases of hortonolite, both of which enhance recrystallization and grain growth of Fe203 crystalloids. The RI of product pellets is improved because the radius of B3~ is very small and B3＋ is liable to diffuse into the crystal lattice of Fe203, which leads to lattice distortion. And lattice distortion makes Fe203 be reduced easily. In addition, the formations of magnesium ferrite and hortonolite is beneficial to improve the RSI and RDI＋3.15 of product pellets respectively.

关 键 词：巴西赤铁矿 含硼磁铁矿 球团焙烧 冶金性能 还原度 

分 类 号：TF046[冶金工程—冶金物理化学]