| 摘要 |
The invention relates to a method for separating aluminum during calcium silicate production from mineral feed materials (3) comprising mineral raw materials and residual materials, comprising the comminution and mixing (1) of the feed materials with alkali carbonates (2) to form a material mixture (4), calcination (5) of the material mixture with a CO2 partial pressure between 0.05 and 0.2 MPa at 850 to 1100°C, wherein CO2 (6) is released and a calcined product (7) consisting of water-insoluble calcium silicates and water-soluble aluminum compounds is formed, a first elution (8) of the calcined product with water (9) or a liquid aqueous alkali hydroxide and/or alkali carbonate solution in a temperature range of between 0 and 100°C, wherein aluminum in the form of alkali aluminates (alkali Al (OH)4) is dissolved, solid/liquid separation of the dissolved alkali aluminates into a solution (10) rich in alkali Al (OH)4 and an alkali-containing solid (11a) rich in calcium silicate, and precipitation (12) and separation of aluminum hydroxide Al (OH)3 (13) from the solution rich in alkali Al (OH)4 by adding seed crystals and/or by adding CO2 or a gas containing CO2, wherein alkali hydroxides and/or alkali carbonates (14) are formed and remain in the solution. |
