What Are The Preparation Methods Of Aluminum Hydroxide

What are the preparation methods of aluminum hydroxide? Do you know? Next, let's take a look.

1, Bayer process

Bayer process has undergone many changes in the preparation process after so many years of development, but its principle has not changed. The principle of the Bayer process is to use different temperatures and different reaction directions to achieve: in the case of high temperature, the mixture of alumina is blended into the sodium hydroxide solution to obtain a sodium aluminate solution, while impurities such as iron and silicon will not dissolve in hydrogen. After the sodium oxide solution is separated, the temperature is lowered, and the above formula is reversed to obtain the mother liquor of aluminum hydroxide and sodium hydroxide, and the mother liquor of sodium hydroxide can be produced in the next round. The industrial preparation of alumina generally also uses this method, and the obtained aluminum hydroxide is roasted and dehydrated.

2, soda lime sintering method

The soda lime sintering method is to calcin bauxite and limestone at high temperature to obtain sodium aluminate solid, and then gradually separate the obtained impurities, iron oxide forms easily hydrolyzed sodium ferrite, silicon oxide and titanium dioxide form insoluble The calcium silicate and calcium titanate in the water are separated to obtain a sodium aluminate solution, and then carbon dioxide is introduced to precipitate aluminum hydroxide. This method can also be used to prepare aluminum hydroxide.