Integrating Sonocrystallization into Bayer Process for Efficient Oxalate Removal and Resource Conservation in High-Purity Alumina Production

The accumulation of sodium oxalate poses a significant challenge in alumina production, particularly in the manufacturing of high-purity alumina and high-end aluminum materials. Therefore, the process of crystallizing sodium oxalate in Bayer liquor with ultrasonic enhancement has been systematically studied and has already been put into industrial use. By optimizing the process using response surface methodology, a high removal rate of 71.10% is achieved under validated conditions. Industrial implementation of this technology markedly reduces the impurity contents (Na2O, SiO2, Fe2O3, etc.) in alumina products. The purity and quality of the alumina is thereby enhanced, facilitating its use in the manufacture of high-end aluminum materials. And this technology exhibits remarkable economic benefits by lowering operating costs and raising product added value, which confirms its favorable economic viability for industrial application.