Improvements relating to organic aluminium compounds

Aluminas, suitable for catalysts and adsorbents, are prepared by calcining in an air oven at 550 DEG C. for 2 hours, Al3O2(OH)4 7/8 (sucrose) 1/8 , Al3O2(OH)4 31/32 (sucrose) 1/32 and Al3O2(OH)5. The aluminas so prepared have specified surface areas of 466 m.2/gm., 447 m.2/gm. and 462 m.2/gm. and micro-pore volumes of 0.92 ml./gm., 0.85 ml./gm. and 0.87 ml./gm. respectively when these are determined by low temperature gas adsorption at 77.4 DEG K. using nitrogen as adsorbate.ALSO:The invention comprises an organic aluminium compound of the formula Al3O2(OH)x(carbohydrate)y where x+y=5 and y is not more than 1, including compositions comprising a compound as defined together with up to 5% by weight of the alcohol corresponding to the alcoholate, and the preparation thereof by reacting together, while heating under reflux, aluminium alcoholates, water and carbohydrate materials, the amount of water being not more than 2+x moles per 3 moles of aluminium alcoholate. The water and carbohydrate, preferably dissolved in a common solvent, may be added together to a solution of the alcoholate or a solution of water and a solution of carbohydrate may be added concurrently to a solution of the alcoholate or the whole of the carbohydrate in a solvent may be added to the alcoholate followed by the water, preferably in a solvent or part of the water, up to two moles per three moles of the alcoholate may be allowed to react and subsequently the remainder of the water and carbohydrate are added. The product may be allowed to mature in contact with the reaction mixture before filtration. Carbohydrate material includes polyols, monosaccharides, oligosaccharides, ascorbic acid and mixtures of carbohydrate materials such as invert syrups, fancy molasses, refiners molasses, final molasses and honey. The compounds of the invention are antacids but also on calcination give aluminas useful in the field of catalysis and adsorbents (see Division C1).