Process for the preparation of a clay

Claim 1

A PROCESS FOR PREPARING CRACKING CATALYSTS FROM CLAY WHICH COMPRISES: (A) MIXING A CLAY SELECTED FROM THE GROUP CONSISTING OF A KAOLIN AND HALLOYSITE WITH FROM 30 TO 80 PERCENT, BY WEIGHT OF THE CLAY, OF A SODIUM COMPOUND, CAPABLE OF DECOMPOSING ON HEATING TO RELEASE SODIUM IONS FOR REACTION WITH THE CLAY TO FORM A SODIUM-ALUMINA-SILICA COMPLEX, SELECTED FROM THE GROUP CONSISTING OF SODIUM CARBONATE, SODIUM HYDROXIDE, SODIUM SULFITE, AND SODIUM ACID SULFITE, (B) CALCINING THE SODIUM-ALUMINA-SILICA COMPLEX AT A TEMPERATURE OF ABOUT 800 TO 1400*F. FOR ABOUT 1 TO 4 HOURS, (C) ADDING FROM 45 TO 130 WEIGHT PERCENT, BASED ON THE DRY CLAY, OF A STRONG MINERAL ACID TO THE COMPLEX TO GIVE AN ACID CONCENTRATION OF FROM 3 TO 15 WEIGHT PERCENT, THEREBY DISSOLVING A PORTION OF THE ALUMINA PRESENT IN THE CLAY, (D) ADDING SODIUM SILICATE TO SAID COMPLEX IN A QUANTITY SUFFICIENT TO PROVIDE ABOUT 10 TO 50 PERCENT BY WEIGHT OF SILIICA IN THE COMPLEX, (E) REPRECIPITATING THE SOLUBILIZED ALUMINA WITH AMMONIA, (F) FILTLERING AND DRYING THE RESULTING SLURRY, (G) REMOVING SODIUM FROM THE DRIED COMPLEX BY BASE EXCHANGE WITH A 3% BY WEIGHT SOLUTION OF AMMONIUM SULFATE CONTAINING 1% BY WEIGHT OF AMMONIU, HYDROXIDE, AND (H) SUBSEQUENTLY WASHING, REDRYING, AND RECOVERING THE CATALYST PRODUCT.