拜耳赤泥加工制备富钛料

【作者】 曹利军；

【导师】 李军旗；

【作者基本信息】 贵州大学 ， 有色金属冶金， 2009， 硕士

【摘要】 赤泥是铝土矿提取氧化铝之后产生的废渣。在普通条件下,采用拜尔法工艺每生产1t Al₂O₃要产生约0.5～2.5t赤泥,而赤泥中含有百分之五左右的TiO₂,在TiO₂需求量不断增加而资源逐渐减少的今天,赤泥有可能成为生产TiO₂的重要资源之一。本文通过对TiO₂回收过程中主要影响因素的研究,探索回收的最佳条件,为从赤泥中提取有价金属提供实验数据。采用化学分析、X射线衍射和扫描电镜等分析方法,对赤泥的相组成进行了分析,查明了赤泥的矿物成分为钠硅渣、钙硅渣、含铁钙硅渣、白云母、鲕绿泥石、赤铁矿、一水硬铝石、钙钛矿、方解石、锐钛矿等。盐酸浸出赤泥的热力学分析表明,在40-100℃之间的温度下,赤泥的主要化学成分Fe₂O₃、Al₂O₃、CaO、和Na₂O与盐酸反应的△G^θ值都小于零。即在常压条件下,赤泥中的Fe³⁺、Al³⁺、Ca²⁺、Na⁺都能很好的进入到浸出液中而赤泥中的二氧化钛不与稀盐酸反应,留在赤泥渣中,使的二氧化钛的品位得以提高。并从动力学方面分析了浸出试验中需要考虑的影响因数。浸出实验中,通过单因素实验探索了浸出时间、浸出温度、盐酸浓度、盐酸过量系数对氧化铁、氧化铝浸出率和二氧化钛品位的影响,并针对影响二氧化钛品位的因素进行正交实验研究,经过极差分析得出:影响最大的因素是浸出温度,最佳浸出条件为:浸出温度90℃、酸过量系数为1.0、浸出时间为1.5小时、盐酸浓度为6.5Mol/L。验证实验表明在最优实验条件下二氧化钛的品位可以由原来的5.67%提高到28%以上。更多还原

【Abstract】 Red mud is the residue of alumina production.Generally there is around 0.5～2.5t red mud while 1t alumina was produced via bayer method craft,and around 5% is TiO₂ in the residue red mud.Currently the requirements for TiO₂ increase when our limited resource-decrease day by day,in that case red mud is supposed to be one most important raw material for getting TiO₂.I researched several factors which affect the TiO₂ producing status mainly,and find the best conditons,then useful datas can be provided to the TiO₂ produced from red mud.Red mud’s phase compositionc was researched by chemical analysis,X-ray diffraction and Electron scanning,and the components of red mud are sodium-silicon residue、calcium silica slag muscovite berthierine hematite diaspore perovskite calcite anatase and so on.The thermodynamic analysis of hydrochloric acid leaches the red mud shows that all the△G⁰ of red mud main chemical composition Fe₂O₃、Al₂O₃、CaO and Na₂O with acid are minus when the temperature is from 40℃to 100℃.Namely under the normal pressure Fe³⁺、Al³⁺、Ca²⁺、Na⁺ in the red mud can be absorbed by acid while TiO₂ can be left in the residue,here by the content of TiO₂ are increased.By single factor experiment we figure out how the leaching time、leaching temperature、concentration of hydrochloric acid、excessive coefficient of hydrochloric acid affect the leaching rate of Fe₂O₃、Al₂O₃、and the contect of TiO₂.Furthermore the factors which affect contect of TiO₂ seriously are researched by orthogonal experiment, finally via range analysis we can find the most important factor is leaching temperature, and the best leaching condition is 90℃of leaching temperature、1.0 for the excessive coefficient of hydrochloric acid、1.5hours of leaching time、6.5Mol/L of hydrochloric acid concentration.The contect of TiO₂ can be imporved from 5.67%to 28%at least under the best leaching condition.更多还原