富氢气氛下不同含铁炉料的还原行为

 高炉低碳富氢冶炼技术如高炉喷吹煤粉、富氢燃料等会导致炉内炉腹煤气中氢气体积分数增加,为探究富氢对高炉上部炉料的影响,对富氢条件下不同含铁炉料的还原行为进行了试验研究。粉化试验结果表明,在20%H₂(体积分数)条件下,块矿和烧结矿的粉化率明显改善,RDI_{>3.15 mm}分别增加了11.08%和30.23%,同时富氢条件有利于含铁炉料粒度的均匀化。还原试验结果表明,在CO体积分数不变、改变H₂加入量条件下,球团矿和烧结矿还原度最高时的H₂体积分数为25%,块矿H₂体积分数则为10%。在保持(CO+H₂)体积分数30%不变、改变H₂加入量时,当H₂体积分数超过20%时,各含铁炉料的还原度均超过90%。扫描电镜分析结果表明,还原后的块矿明显生成渣相和铁相,球团矿出现良好的赤铁矿和磁铁矿相,烧结矿则呈“针状铁酸钙相-磁铁矿相-铁相”分层现象。

Reduction behavior of iron-bearing burdens in hydrogen-rich stream

The Low carbon and hydrogen-rich smelting technology of the blast furnace, such as pulverized coal injection and hydrogen-rich fuel injection, will lead to the increase of hydrogen content in the bosh gas of blast furnace. In order to explore the influence of hydrogen-rich on the upper burden of blast furnace, the reduction behavior of different iron-containing burdens under the condition of hydrogen-rich is studied. The pulverization experiment found that under the condition of 20%H₂(volume percent), the pulverization rate of lump ore and sinter is obviously improved, and RDI_{>3.15 mm} is increased by 11.08% and 30.23% respectively. At the same time, the condition of rich hydrogen is conducive to the homogenization of iron-containing burdens. The reduction experiment shows that under the condition of constant CO volume percent and changing the content of H₂, the H₂ volume percent of pellet and sinter is 25% at the highest reduction degree, and that of lump ore is 10%. When the volume percent of (CO+H₂) is kept at 30% and the amount of H₂ is changed, when the volume percent of H₂ is more than 20%, the reduction degree of each iron-containing burdens is more than 90%. The results of SEM analysis show that the reduced block ore obviously produces slag and iron phase, the pellet ore presents good hematite and magnetite phase, and the acicular calcium ferrite phase-magnetite phase-iron phase appeared in the sinter.