优化配矿强化西澳超细粒磁铁精矿球团焙烧研究

进行了西澳超细粒磁铁精矿分别配加国产磁铁精矿和巴西赤铁精矿制备氧化球团矿的实验研究.结果表明，以100%西澳超细磁铁精矿为原料制备氧化球团矿时，球团预热及焙烧性能较差，在预热温度为1050℃、预热时间20 min及焙烧温度1300℃、焙烧时间40 min的条件下，预热球团和焙烧球团矿抗压强度分别为每个502和2313 N.西澳超细粒磁铁精矿配加40%国产磁铁精矿或20%巴西赤铁精矿时，球团适宜预热温度由1050℃分别降低到950和975℃，适宜的焙烧温度由1300℃分别降低到1250和1280℃；而且焙烧球团矿的抗压强度分别提高到每个2746 N和每个2630 N.焙烧球团矿的微观结构研究表明:配加国产磁铁精矿后，焙烧球团矿中Fe₂O₃晶粒发育优良，晶粒间互联程度提高，晶粒粗大，孔隙率低，固结更加紧密.配加20%巴西赤铁精矿时，焙烧球团矿中Fe₂O₃晶粒基本连接成片，Fe₂O₃晶体发育良好.优化配矿是改善西澳超细粒磁铁精矿球团矿预热及焙烧性能的有效途径. 

Optimization of feed blends to enhance the roasting performance of pellets made from Western Australian ultrafine magnetite concentrate

The conducted roasting tests were studied which pellets were made from blends of Western Australia ultrafine (WAU) magnetite concentrate and domestic magnetite concentrate or Brazilian hematite concentrate. The results show that the pellets made from 100% WAU magnetite concentrate exhibit inferior preheating and roasting performance under the following conditions:preheating at 1050℃ for 20 min and roasting at 1300℃ for 40 min, with compressive strengths of the preheated and fired pellets of each pellet 502 N and 2313 N, respectively. When blended 40% domestic magnetite concentrate or 20% Brazilian hematite concentrate with 60% or 80% WAU magnetite concentrate, the appropriate preheating and firing temperatures of the pellets are reduced from 1050℃ to 950℃ and 975℃, and from 1300℃ to 1250℃ and 1280℃, respectively. Moreover, the compressive strength of the fired pellets obviously improves to more than each pellet 2500 N. The microstructure of fired pellets made from WAU and domestic magnetite concentrate is characterized by fully grown Fe₂O₃ grains and close interlinkages among the hematite grains, which leads to low porosity and strong consolidation. In contrast, 20% Brazilian hematite concentrate blended with WAU magnetite concentrate yields nearly grown Fe₂O₃ grains in the fired pellets and only relatively close interlinkages between the hematite grains. The preheating and roasting performance of WAU magnetite concentrate pellets can be improved by optimizing the ore matching.