The production of aluminum ingot is composed of bauxite mining, alumina production, aluminum electrolysis and other production links.
First, the bauxite is mined, and then the aluminum ore powder is produced through the process of washing and grinding, and then the alumina is obtained through the four complex processes such as roasting. There are three main types of bauxite for the production of alumina: diaspore, diaspore, diaspore.
Of the proven global bauxite reserves, 92% are weathered laterite bauxite, which belongs to the traspite type. These bauxites are characterized by low silicon, high iron, and high Al/Si ratio, and are concentrated in West Africa, Oceania, and Central and South America. The remaining 8% is sedimentary bauxite, belonging to diaspore and diaspore types, of medium and low grade, mainly distributed in Greece, former Yugoslavia and Hungary.
Due to the different characteristics of the three kinds of bauxite, different production processes have been adopted in the alumina production enterprises, including Bayer process, alkali lime sintering method and Bayer - sintering combined method. Usually, bauxite with high grade is produced by Bayer method, while bauxite with low grade is produced by combination method or sintering method. Bayer process because of its simple process, low energy consumption, has become the current alumina production in the application of a relatively major method, the output of about 95% of the total global alumina production.