Reactivation of thermactivated catalyst

Claim 1

IN THE PROCESS OF REACTIVATING A HYDROCRACKING CATALYST WHICH, BEFORE EXPOSURE TO HYDROCARBON OIL, IS A HIGH SURFACE AREA CATALYST COMPROSITION COMPOSED OF AN ACTIVE CRACKING SUPPORT HAVING DISPOSED THEREON A HYDROGENATING METAL COMPONENT SELECTED FROM THE GROUP CONSISTING OF GROUP VI AND GROUP VII METALS AND COMPOUNDS THEREOF OTHER THAN NOBLE METALS AND COMPOUNDS THEREOF AND WHICH CATALYST, BEFORE EXPOSURE TO HYDROCARBON OIL, HAS BEEN ACTIVATED BY HEATING IN A NON-REDUCING ATMOSPHERE AT 1200-1500*F. FOR 0.25-48 HOURS SUFFICIENT TO ACTIVATE THE COMPOSITE CATALYST, BUT WHICH CATALYST, AFTER BEING CONTACTED WITH AN OIL UNDER CONDITIONS TO DEPOSIT A CARBONACEOUS COATING THEREON, HAS BECOME DEACTIVATED, THE IMPROVEMENT WHICH COMPRISES IMPREGNATING THE RESULTANT COATED CATALYST COMPOSITION WITH AN AQUEOUS SOLUTION OF AT LAST ONE HYDROGENATING METAL SALT, SAID HYDROGENATING METAL BEING SELECTED FROM GROUPS VI AND VIII OF THE PERIODIC TABLE OTHER THAN NOBLE METALS AND THE AMOUNT OF SAID SALT BEING SUFFICIENT TO ADD AT LEAST ONE PERCENT OF SAID METAL SALT, CALCULATED ON A METAL BASIS, TO THE CATALYST COMPOSITION, DRYING SAID IMPREGNATED CATALYST COMPOSITION, AND HEATING THE CATALYST AT TEMPERATURES BELOW ABOUT 1100*F. TO DECOMPOSE THE HYDROGENATING METAL SALTS AND TO REMOVE THE CARBONACEOUS DEPOSITS.