Patent ID: 8147795

Claim:
A process for preparing boehmitic aluminas by hydrolysis of aluminium alcoholates in aqueous, alkaline solution forming a mixture, followed by hydrothermal aging, characterised in that (A) the hydrolysis is carried out at pH values above 9.5 at a temperature of from 50° to 95° C. and the hydrolysis and/or the hydrothermal aging of the mixture resulting from the hydrolysis is carried out in the presence of 0.1 to 0.5 wt. % of carboxylic acids having at least one additional substituent, the salts thereof or their derivatives which during hydrolysis and/or the hydrothermal aging are at least partially converted into the free carboxylic acid or the dissociated form thereof, wherein said at least one additional substituent is selected from the group consisting of hydroxy-, oxo- and amino groups; and (B) the boehmitic aluminas prepared in step (A) are subjected to an aging step at 120° C. to 250° C. for at least 1 hour to provide a boehmitic alumina which converts to an alpha phase only at a temperature of above 1350° C.