Method for producing attrition resistant sorptive alumina particles

Claim 1

IN THE METHOD OF MAKING PARTICLES OF SORPTIVE ALUMINA IN WHICH PARTICLES OF HYDRATED ALUMINA ARE CALCINED AT A TEMPERATURE OF ABOUT 800*F. TO TRANSFORM THE HYDRATED ALUMINA PRECURSOR PARTICLES INTO SORPTIVE ALUMINA PARTICLES THE IMPROVEMENT WHICH CONSISTS OF: PREPARING A MIXTURE CONSISTING ESSENTAILLY OF FROM 50% TO 90% OF CARSE HYDRATED ALUMINA PARTICLES HAVING A PREDOMINANT DIAMETER RANGE OF ABOUT 10 TO ABOUT 100 MICRONS AND FROM 10% TO 50% OF A PULVERIZED HYDRATED ALUMINA PARTICLES HAVING A PREDOMINANT DIAMETER OF NOT MORE THAN ABOUT 1 MICRON; ADDING TO THE RESULTING MIXTURE OF HYDRATED ALUMINAS AN AQUEOUS ACIDIC SOLUTION IN AN AMOUNT CORRESPONDING TO 1 LITER OF SOLUTION FOR EACH FIVE TO TEN KILOGRAMS OF HYDRATED ALUMINA, THE ACID BEING SUFFICIENT TO STOICHIOMETRICALLY COMBINE WITH ABOUT 5 TO ABOUT 15 PERCENT BY WEIGHT OF THE ALUMINA IN THE HYDRATED ALUMINA TO PREPARE A MOIST, ADHESIVE MASS HAVING AN EXTRUDABLE CONSISTENCY TENDING TO ADHERE TOGETEHR ANDAGEGLOMERATE WHEN SQUEEZED; MIXING SAID MOIST, ADHESIVE MASS SUFFICIENTLY TO FORM PRECURSOR PARTICLES HAVING A SPHEROIDAL BALL SHPAE; AGING THE PRECURSOR PARTICLES IN THE PRESENCE OF HIGH HUMIDITY AT CONDITIONS AT WHICH EVAPORATION OW WATER FROM THE PARTICLES IS SUBSTANTIALLY ELIMINATED; SUBJECTING THE THUS AGED PRECURSOR PARTICLES TO CALCINATION; AND COOLING THE CALCINED PARTICLES TO PROVIDE SORPTIVE ALUMINA PATICLES.