Recovery of aluminium from anodic oxidation bath - by crystallisation of aluminium sulphate-contg. complex salts

摘要

Recovery of aluminium from an eloxal bath (anodic oxidation of aluminium) by crystallisation of aluminium sulphate is improved by cooling the electrolyte to 3-10 degrees C, then adding a complex-forming salt of NH4 and/or Na esp. sulphate and intensively stirring. The resulting aluminium ammonium sulphate crystals are sepd. by centrifuging. The removal of Al from the bath is carried out rapidly and the period of bath regeneration is short.