Preparation of alumina gels

Claim 1

A PROCESS FOR FORMATION OF ALUMINA-CONTAINING GELS COMPRISING REACTING IN AQUEOUS SOLUTION A WATER-SOLUBLE BASIC ALUMINUM SALT SELECTED FROM THE GROUP CONSISTING OF BASIC ALUMINUM CHLORIDE AND BASIC ALUMINUM NITRATE, UREA, AND A WATER-SOLUBLE SALT SELECTED FROM THE GROUP CONSISTING OF AMMONIUM AN ALKALI METAL SALTS OF ACETIC AND GLYCOLIC ACIDS TO EFFECT FORMATION OF A HOMOGENEOUS HYDROSOL IN WHICH ALUMINA IS THE MAJOR WATER-INSOLUBLE INORGANIC OXIDE COMPONENT AND WHICH HAS A PH BETWEEN ABOUT 3.5 AND ABOUT 7, PERMITTING SAIE HYDROSOL TO SET TO AN ALL-EMBRACING ALUMINA-CONTAINING HYDROGEL, AGING THE RESULTING HYDROGEL IN A WATER-IMMISCIBLE LIQUID AT A TEMPERATURE BETWEEN ABOUT 125*F. AND ABOUT 212*F. FOR AT LEAST 10 HOURS TO SLOWLY DECOMPOSE THE UREA CONTAINED THEREIN AND TO RAISE THE PH OF THE HYDROGEL TO A VALUE ABOVE ABOUT 8, WHEREBY THE HYDROGEL IS RENDERED RESISTANT TO DISINTEGRATION UPON CONTACTING WITH AQUEOUS MEDIA, WASHING THE AGED HYDROGEL FREE OF WATER-SOLUBLE MATTER, AND DRYING.