Alumina is the main raw material for aluminum electrolysis production. Industrial alumina is extracted from bauxite by alumina plants. The quality requirements of aluminum electrolysis for alumina are mainly chemical purity and physical properties. Chemical purity mainly affects the grade of primary aluminum, and its physical properties play an important role in ensuring the normal operation of the electrolysis process. Alumina is usually required to have the characteristics of low water absorption, high activity, suitable particle size and good solubility in electrolyte. The development of modern large-scale aluminum reduction cells and the environmental regulations on fluorine content in the air require that alumina has a large specific surface area and can effectively absorb hydrogen fluoride gas. These physical properties depend primarily on the crystal morphology, size and shape of the alumina. According to the different physical properties of alumina, it is generally divided into three categories: sandy, intermediate and powdery