Deoiling of spheroidal chromia-alumina hydrogel particles

Claim 1

IN THE PRODUCTION OF CHROMINA-ALUMINA SPHEROIDAL GEL PARTIES PREPARED BY MIXING AQUEOUS SOLUTIONS OF SODIUM ALUMINATE AND CHROMIUM ACETATE AND CONTROLLING THE SODIUM TO ALUMINUM ION RATIO AND THE ACETATE TO CHROMIUM ION RATIO IN SAID SOLUTIONS TO YIELD A HYDROSOL HAVING A CHROMIA-ALUMINA CONTENT OF AT LEAST ABOUT 10 PERCENT BY WEIGHT AND CHARACTERIZED BY AN INHERENT CAPACITY OF SET TO A HYDROGEL UPON LAPSE OF A SUITABLE PERIOD OF TIME, ADMITTING SAID SOL IN THE FORM OF SEPARATE GLOBULES TO A BODY OF A LIQUID SUBSTANTIALLY IMMISCIBLE WITH WATER WHEREIN THE GLOBULES ASSUME A SPHEROIDAL SHAPE AND SET TO HYDROGEL, AGING, WASHING, AND DRYING THE SPHEROIDAL HYDROGEL, THE IMPROVEMENT WHICH COMPRISES REMOVING ADHERENT SUBSTANTIALLY WATER-IMMISCIBLE LIQUID FROM THE FRESHLY FORMED HYDROGEL PARTICLES AFTER SEPARATION THEREOF FROM SAID BODY OF LIQUID, BUT PRIOR TO SAID AGING, BY WASHING SAID PARTICLES WITH AN AQUEOUS AMMONIUM SALT SOLUTION HAVING A PH OF BETWEEN ABOUT 8.0 AND ABOUT 9.5 AND AN AMMONIUM SALT CONCENTRATION OF BETWEEN ABOUT 5 AND ABOUT 20 PERCENT BY WEIGHT.