拜耳法赤泥中铁的提取及残渣制备建材  

Recovering iron and preparing building material with residues from Bayer red mud

作　　者：刘万超[1] 杨家宽[1] 肖波[1] 

机构地区：[1]华中科技大学环境科学与工程学院,武汉430074

出　　处：《中国有色金属学报》2008年第1期187-192,共6页The Chinese Journal of Nonferrous Metals

摘　　要：以拜耳法赤泥为原料,经直接还原焙烧?磁选回收铁,磁选残渣用于生产建筑材料。该赤泥中的氧化铁含量27.93%,并以赤(褐)铁矿为主要存在状态。在探讨了焙烧温度、焙烧时间、炭粉及添加剂用量等因素对实验结果影响的基础上,得出较理想的焙烧条件。在该条件下,经磨细磁选后所得精矿中,总铁含量89.05%,金属化率96.98%,回收率81.40%,可用作海绵铁。磁选残渣掺入消石灰经压力成形、蒸汽养护,试件抗压强度可以达到24.10 MPa,可用于生产蒸养砖等建材。残渣在蒸养前后主要矿物组成由霞石转化为钙铝黄长石,热力学分析证明了在实验条件下该反应发生的可能性。Recovery of iron was investigated from red mud （RM） with direct reduction roasting process followed by magnetic separation, and building materials were prepared from residues from magnetic separation process. The effects of different parameters on recovery efficiency of ferrous were studied. The optimum reaction parameters were obtained. The results show that the content of Fe2O3 in RM is 27.93%, and hematite and limonite are the major crystalline phase. With the optimum parameters the content of iron in the magnetic separated part is 89.05%, the metallization ratio is 97.69% and the recovery ratio is 81.40%. Construction bricks can be prepared from the residues with the addition hydrated lime followed by mould in a hydraulic machine, and cured with an autoclaved steam. The mean compressive strength of the brick specimens is 24.10 MPa. Main mineral phases are transformed from nepheline in residues to gehlenite in the autoclaved brick specimens. The feasibility of the mineral phase transformation under the experimental conditions is proved by thermodynamics calculation analysis.

关 键 词：拜耳法赤泥 铁回收 建材 综合利用 

分 类 号：TG146.2[一般工业技术—材料科学与工程]