Method of making catalysts

Claim 2

A PROCESS OF PREPARING SILICA ALUMINA CATALYSTS CONTAINING HIGH AMOUNTS OF ALUMINA IN EXCESS OF ABOUT 20% CONSISTING OF PREPARING A SILICA HYDROSOL HAVING A PH BELOW ABOUT 5.5, EFFECTING PARTIAL GELATION OF THE SILICA HYDROSOL AT SAID PH, THEN ADDING AN ACIDIC AQUEOUS ALUMINUM SALT SOLUTION TO SAID PARTIALLY GELLED SILIC HYDROSOL AND THEREBY LOWERING THE PH OF THE MIXTURE, HOLDING THE RESULTANT MIXTURE FOR A LIMITED TIME AT THE LOWERED PH, THEN ADDING ONLY A SUFFICIENT AMOUNT OF AN AQUEOUS SOLUTION OF AMMONIA WITH AGITATION TO RAISE THE PH OF THE MIXTURE TO ABOUT 4.0 TO 5.0 AND CAUSE THE COMBINATION OF ALUMINA WITH THE SILICA, AGING THE RESULTING MIXTURE FOR A PERIOD OF TIME TO EFFECT SLOW AND SUBSTANTIALLY COMPLETE PRECIPITATION OF ALUMINA, THEN ADDING ADDITIONAL AQUEOUS AMMONIA WITH AGITATION TO RAISE THE PH TO ABOUT 6.5 TO 7.5 AND CAUSE PRECIPITATION OF THE REMAINING ALUMINA, DEWATERING THE SUSPENSION OF SILICAALUMINA HYDROGEL, AND THEN DRYING, WASHING AND REDRYING THE GEL PARTICLES TO PRODUCE AN IMPROVED CATALYST.

Claim 3

A PROCESS FOR CRACKING HYDROCARBON OILS WHICH COMPRISES PASSING THE OIL UNDER CRACKING CONDITIONS THROUGH A CRACKING ZONE CONTAINING A SILICA-ALUMINA CATALYST CONTAINING IN EXCESS OF ABOUT 20% ALUMINA PREPARED BY A PROCESS CONSISTING OF FORMING A SILICA HYDROSOL HAVING A PH BELOW ABOUT 5.5, EFFECTING PARTIAL GELATION OF SAID HYDROSOL AT SAID PH,. ADDING TO SAID PARTIALLY GELLED SILICA HYDROSOL AN ACIDIC AQUEOUS ALUMINUM SALT SOLUTION AND THEREBY LOWERING THE PH OF TH MIXTUR, HOLDING THE RESULTANT MIXTURE FOR A LIMITED TIME AT THE LOWERED PH. ADDING THERETO WITH AGITATION AN AMOUNT OF ALKALINE AGENT SUFFICIENT TO RAISE THE PH OF THE MIXTURE TO ABOUT 4.0 TO 5.0 AND CAUSE THE COMBINATION OF ALUMINA WITH THE SILICA, AGING THE RESULTING MIXTURE TO EFFECT SLOW AND SUBSTANTIALLY COMPLETE PRECIPITATION OF ALUMINA, THEN ADDING ADDITIONAL ALKALINE AGENT WITH AGITATION TO RAISE THE PH TO ABOUT 6.5 TO 7.5 AND CAUSE PRECIPITATION OF THE REMAINING ALUMINA, FILTERING THE RESULTING SILICA-ALUMINA COMPOSITE, AND THEN DRYING, WASHING, AND REDRYING THE COMPOSITE.

Claim 4

A PROCESS FOR CRACKING HYDROCARBON OILS WHICH COMPRISES PASSING THE OIL UNDER CRACKING CONDITIONS THROUGH A CRACKING ZONE CONTAINING A SILICA-ALUMINA CATALYST CONTAINING IN EXCESS OF ABOUT 20% ALUMINA PREPARED BY A PROCESS CONSISTING OF FORMING A SILICA HYDROSOL HAVING A PH BELOW ABOUT 5.5, EFFECTING PARTIAL GELATION OF SAID HYDROSOL AT SAID PH,. ADDING TO SAID PARTIALLY GELLED SILICA HYDROSOL AN ACIDIC AQUEOUS ALUMINUM SALT SOLUTION AND THEREBY LOWERING THE PH OF TH MIXTUR, HOLDING THE RESULTANT MIXTURE FOR A LIMITED TIME AT THE LOWERED PH. ADDING THERETO WITH AGITATION AN AMOUNT OF ALKALINE AGENT SUFFICIENT TO RAISE THE PH OF THE MIXTURE TO ABOUT 4.0 TO 5.0 AND CAUSE THE COMBINATION OF ALUMINA WITH THE SILICA, AGING THE RESULTING MIXTURE TO EFFECT SLOW AND SUBSTANTIALLY COMPLETE PRECIPITATION OF ALUMINA, THEN ADDING ADDITIONAL ALKALINE AGENT WITH AGITATION TO RAISE THE PH TO ABOUT 6.5 TO 7.5 AND CAUSE PRECIPITATION OF THE REMAINING ALUMINA, FILTERING THE RESULTING SILICA-ALUMINA COMPOSITE, AND THEN DRYING, WASHING, AND REDRYING THE COMPOSITE.