Aluminum hydroxide production primarily involves the sodium aluminate process, the carbon fractionation process, and the Bayer process.
1. Sodium Aluminate Process
A sodium aluminate solution is neutralized with aluminum sulfate to a pH of 6.5 to produce an aluminum hydroxide precipitate. The product is then filtered, washed, and dried to obtain the product.
2. Carbon Fractionation Process
Carbon dioxide is introduced into the sodium aluminate solution to produce an aluminum hydroxide precipitate. This process allows the particle size distribution of the product to be adjusted by controlling the amount of carbon dioxide introduced.
3. Bayer Process
Aluminum hydroxide is an intermediate product extracted from bauxite and then calcined to produce alumina. As an intermediate product in this process, the purity of aluminum hydroxide directly affects the quality of the final alumina.
