Method for preparing an alumina catalyst base

Claim 1

A M ETHOD OF PREPARING A POROUS ALUMINA CATALYST BASE CHARACTERIZED BY AN APPARENT BULK DENSITY OF LESS THAN 0.80 GRAM PER CC. WHICH COMPRISES REACTING TOGETHER AN AQUEOUS SOLUTION OF AN ALKALI DI-METAL CARBONATE AND A WATER-SOLUBLE ALUMINATE, ADJ/USTING THE PH OF SAID REACTION MIXTURE OF LESS THAN 7 WITH AN ACIDIC WATER-SOLUBLE ALUMINUM SALT, THEREAFTER ADJUSTING THE PH OF SAID REACTANTS TO ABOVE 7.5 BUT LESS THAN 9.5 WITH ADDITIONAL QUANTITIES OF SAID WATER-SOLUBLE ALUMINATE, HEATING SAID DILUTE AQUEOUS ALKALINE REACTION MASS TO ABOVE 75*F. BUT NOT ABOVE ABOUT 150*F., RECOVERING THE ALUMINUM HYDRATE PRECIPITATE INCLUDING THE OCCLUDED AND CO-PRECIPITATED CONTAMINANTS, SPRAY DRYING THE CRUDE PRECIPITATE AT A TEMPERATURE WITHIN THE RANGE OF 150*F. TO 325*F. UNDER A SPRAY HEAD PRESSURE SUFFICIENT TO FORM MICROSPHERES AND WATER WASHING THE THUS DRIED MICROSPHERES OF ALUMINUM HYDRATE UNTIL THE CONTAMINANTS HAVE BEEN SUBSTANTIALLY DISPLACED FROM THE SO-PREPARED ALUMINUM HYDRARE PARTICLES.