| 摘要 |
In a process for regenerating alkaline solutions for pickling aluminium, in which aluminium hydroxide is recovered, a pickling solution containing alkali hydroxide, aluminate, a complex builder and other additives is transferred from a pickling bath into a reactor section consisting of at least one reactor, where aluminium is precipitated as aluminium hydroxide. The temperature of the pickling bath is higher than that of the reactor section. The process is operated so that the concentration of aluminate, alkali and gluconate and the temperature in the pickling bath, on the one hand, and the temperature drop from the pickling bath to the reactor section, on the other hand, are adjusted so that the pickling solution in the pickling bath is undersaturated or metastably supersaturated in relation to the precipitation of aluminium hydroxide but unstably supersaturated in the reaction section. A device for carrying out the process of the invention is also disclosed. |
