【作者】 王瑞芬；

【导师】 孙忠；

【作者基本信息】 内蒙古大学 ， 物理化学， 2007， 硕士

【摘要】 本文采用铝粉调节氯化铝溶液的碱化度，采用湿渣法，通过测定大量湿渣和共存饱和母液的组成，采集大量数据绘制了AlCl₃—Al₂O₃—H₂O三元体系75℃下的固液平衡相图，以所测相图为指导，确定了不同产物在75℃下析出单一结晶相的控制条件，实现了制备过程的有效控制，在国内首次成功制备了三种水合氯化多聚铝结晶。粉末XRD物相分析表明，产物Ⅰ、Ⅱ和Ⅲ中主要物相分别为：四水合氯化五聚铝（AlCl₃·4Al（OH）₃·4H₂O）、七点五水合氯化五聚铝（AlCl₃·4Al（OH）₃·7.5H₂O）和十八水合氯化九聚铝（2AlCl₃·7Al（OH）₃·18H₂O）；化学分析表明其纯度依次为93.00％、99.51％和88.68％。为进一步纯化并研究其晶体结构准备了条件。三种产物均是在75℃下恒温结晶而得，常温下在水中的溶解性不好，比较而言，产物Ⅲ的溶解性比其它二者稍好一些。采用Al-Ferron逐时络合比色法测定了产物Ⅰ、Ⅱ和Ⅲ中铝的形态分布，Al_b含量分别为：15.03％、34.03％和20.78％。产物Ⅰ、Ⅱ和Ⅲ中其他两种形态Al_a和Al_c的含量分别为：6.72％、78.26％；18.01％、61.22％和2.01％、63.96％，三种产物均是以Al_c为主要分布形态。高岭土模拟水样絮凝实验表明，产物Ⅲ在弱酸性条件下絮凝性能良好，但产物Ⅰ和Ⅱ只在特定的环境和投加量下表现一定程度的絮凝性。更多还原

【Abstract】 According to a numbers of analytical data, the solid-liquid equilibrium diagramof AlCl₃—Al₂O₃—H₂O at 75℃is obtained with the method of wet dregs by detectingthe compositions of the dregs and their saturated solution simultaneously. Under theguide of the diagram, the preparing processes of expected products are controlledeffectively by the means of using aluminium powder to adjust the basicity of thesolution of aluminium chloride and, the optimal crystalline conditions to form purecompounds are obtained and, three kinds of purer hydrated polyaluminium chloridescrystals are prepared firstly in China. The main phases which are identified by powderXRD method are: AlCl₃·4Al（OH）₃·4H₂O, AlCl₃·4Al（OH）₃·7.5H₂O and2AlCl₃·7Al（OH）₃·18H₂O in productⅠ,ⅡandⅢrespectively. The purities whichare detected by chemical analysis are: 93.00%, 99.51% and 88.68% of productⅠ, ⅡandⅢrespectively. These result compounds will be important samples to bepurified their crystals further and to be resolved their crystal structures finally.All of these three products have poor solubility in water at room tempreture, butcomparatively, productⅢhas better solubility. The poor solubility may result fromthe higher crystallization temperature, because these products are crystallized at75℃.The distribution of aluminium species in the solutions of productⅠ（including AlCl₃·4Al（OH）₃·4H₂O mainly）, productⅡ（includingAlCl₃·4Al（OH）₃·7.5H₂O mainly）, and productⅢ（including 2AlCl₃·7Al（OH）₃·18H₂Omainly）, are studied by using Al-Ferron time complex colorimetric method, and theresults show the Al_b’s contents are 15.03 %, 34.03 % and 20.78% respectively（Ala& Alc’s contents are 6.72%、78.26%; 18.01%、61.22% and 2.01%、63.96%）. Theflocculation test using kaoline simulated suspending water indicates that productⅢhas good flocculation performance at weak acid condition, but productⅠandproductⅡonly have limited flocculation ability just at certain concentration andappropriate condition.更多还原