络合—结晶法脱异丙醇铝及氧化铝纳米粉体中痕量铁的研究

【作者】 居鸣丽；

【导师】 宁桂玲；

【作者基本信息】 大连理工大学 ， 化学工艺， 2004， 硕士

【摘要】 异丙醇铝是合成多种重要材料的前驱体，近年来在高纯超细氧化铝粉体材料和铝酸盐系发光材料等领域得到广泛应用并显示出它的优越性。但是异丙醇铝中痕量铁是影响其应用性能的重要因素，因此有关铝醇盐中痕量铁的分离与纯化技术受到极大关注。目前工业生产中多采用减压蒸馏法来纯化由工业铝为原料制得的异丙醇铝。由于结晶法具有能耗低、分离能力大等优点，本文根据异丙醇铝本身的物理化学特性，选用异丙醇为溶剂，研究了用络合—结晶方式去除异丙醇铝及氧化铝中微量铁的纯化方法。 本文主要进行了以下几个方面的研究： （1）建立了一种简单的、适合于异丙醇铝中痕量铁分析的实验室技术，探讨了这种方法的灵敏度、准确度和影响准确度的因素，确定出这种新方法的使用条件和适用范围。（2）研究了结晶法除铁的适合结晶方式、结晶时间及溶液浓度。（3）通过实验，研究了络合—结晶的除铁效果，并选出除铁效果较好的几种络合剂，研究了除铁效果与结晶溶液浓度的关系，以及适合的络合剂与铁杂质的摩尔比。并在氧化铝纳米粉末制备过程中通过添加络合剂来除铁。（4）提出用酸浸泡氧化铝粉末，再去离子水洗涤过滤，将铁杂质与氧化铝分离的方法。分别研究了盐酸和硝酸浸泡用量及浸泡时间对氧化铝除铁的影响。 通过实验结果分析，本文选用超声波作用后静置结晶的方法，采用结晶时间为两天。研究结果表明，较高的溶液浓度有利于异丙醇铝的除铁；在结晶溶剂异丙醇中添加络合剂进行络合—结晶可以提高结晶法除铁的效率；选出除铁效果较好的络合剂——8-羟基喹啉、乙酰丙酮和有机试剂L₃、L₄应用于氧化铝纳米粉末的制备过程中，发现L₃和乙酰丙酮的除铁效果较好，但在氧化铝纳米粉末制备过程中添加络合剂的除铁效果没有络合—结晶法的除铁效果好。更多还原

【Abstract】 Aluminium isopropoxide [Al(OC3H7)3] is the precursor of many important materials, which has been applied to the preparation of high-purity alumina nanometer powders and phosphors, and has shown its merits. However, the trace iron in the Al(OC3H7)3 dramatically affects properties of products made from Al(OC3H7)3. In this thesis, a complexation-crystallization purification technique was used to remove the trace iron in Al(OC3H7)3, because it has a lot of advantages such as low energy cost, high separation ability, low temperature and so on. The details of this complexation-crystallization technique was studied in this thesis.Several aspects of study were investigated in this thesis: (1) A sensitive and simple analysis method concerning the trace iron in aluminium isopropoxide [Al(OC3H7)3] based on the 1,10-phenanthroline spectrophotometry was proposed. This method had been applied to the determination of the trace iron in [Al (OC3H7)3] with satisfactory results. (2) The optimum conditions for the complexation-crystallization such as the crystallization means, crystallization time and the solution concentration were determined. (3) Through experiments, several complexes with a good iron-removal effect were selected, the optimum solution concentration and molar ratio to the iron were determined. These selected complexes were also added in the process of preparing alumina nanometer powders to remove the iron. (4) A purification method of marinating alumina powder with HCl/HNO3 to remove the iron was proposed.The results show: the complexation-crystallization can enhance the efficiency of normal crystallization purification. At the higher solution concentration, more iron can be removed. Hox, AA and complex L3, L4 which had better iron-removal effect in the complexation-crystallization was chosen in the process of preparing alumina nanometer powder, however the iron-removal effect was not so good as the one in the complexation-crystallization.更多还原