A comparative study of alumina prepared from aluminum chloride solution by electrotransformation method and by sodium hydroxide titration method

At present, there are many methods for preparing alumina from aluminum chloride solution in our country. However, these methods have some shortcomings, such as producing waste acid and salt, requiring demanding preparation conditions, producing toxic and harmful substances in the reaction, and so on. In this case, inspired by the chlorine-alkali industry, Northeastern University has proposed a new method for the preparation of alumina by electrochemical conversion of AlCl₃ aqueous solution. And the method has been verified experimentally. This paper investigates the differences in infrared spectrum and particle size distribution of alumina precursor prepared by electrochemical transformation and the one prepared by sodium hydroxide titration. At the same time, this paper also studies the differences in phase, morphology and particle size between the two kinds of alumina precursors. The results show that the alumina precursors prepared by the two methods contained Al element and Al-OH bond, and the precursors' roasted products are all alumina. In addition, compared with alumina prepared by sodium hydroxide titration, the morphology of alumina prepared by electrochemical transformation is more regular and flake-like, while the shape of alumina prepared by sodium hydroxide titration is irregular. Meanwhile, alumina and its precursor prepared by electrochemical transformation have smaller particle size and more regular particle size distribution than those prepared by sodium hydroxide titration.