Method of producing an alumina dispersible at a pH greater than 8

A method of making an alumina which is highly dispersible at a pH of greater than 8 including the following steps:

• i) providing an alumina slurry which includes aluminum oxyhydroxide, aluminum oxide, aluminum hydroxide, or mixtures thereof;
• ii) aging the alumina slurry to form an aged alumina slurry including alumina having a crystallite size of from 38 to 450 Å for the 120 crystal plane;
• iii) adding a tricarboxylic acid to the aged alumina slurry to form an acid modified slurry;
• iv) aging the acid modified slurry at a temperature of between 75° C. and 125° C. to form a product slurry;
• and
• v) spray drying the product slurry to form the alumina with a dispersibility at a pH of greater than 8 above 90% and a viscosity below 1 Pa·S for 10 wt. % sols,
• the method being characterised by the addition of a dicarboxylic acid either in step iii) of the process with the tricarboxylic acid or by adding the dicarboxylic acid to the product slurry after step iv) before spray drying in step v).