Preparation of Aluminum Hydroxide During the Synthesis of High Purity Alumina via Aluminum Anodic Oxidation

Abstract

High purity alumina is one of the main products on the ceramic powder market. In this study, a promising technology for the synthesis of high purity alumina by the electrochemical method was considered. The main objective of the study was the preparation of aluminum hydroxide obtained by aluminum anodic oxidation. The technological scheme of the process with the certain parameters of each stage was presented. The dependence of the residual electrolyte impurities content on the washing modes of aluminum hydroxide was revealed. Appropriate treatment parameters of aluminum hydroxide obtained by anodic oxidation of aluminum were proposed. Changes in the chlorine content during washing and calcination of aluminum hydroxide were investigated. The processes of by-products formation in the electrolyte were discussed. Technical solutions of the filtrate usage after washing of aluminum hydroxide were proposed. High purity alumina with less than 30 ppm of impurities using studied parameters was obtained.