Coking of hydrocarbons with the removal of metallic contaminants from the coke

Claim 1

IN A METHOD OF COKING HEAVY PETROLEUM OILS TO PRODUCE COKE CONTAINING METAL IMPURITIES AND LOWER BOILING HYDROCARBONS WHEREIN THE OIL IS CRACKED IN A COKING REACTION ZONE AND COKE PARTICLES ARE PARTIALLY BURNED IN A BURNER ZONE AND RECYCLED TO SAID COKING REACTION ZONE TO SUPPLY THE HEAT OF CRACKING, THE IMPROVEMENT WHICH COMPRISES WITHDRAWING A PORTION OF THE COKE PARTICLES FROM SAID REACTOR ZONE AND PASSING THEM TO A SEPARATE CONFINED TREATING ZONE TO BURN AT LEAST A PORTION OF THE COKE PARTICLES IN THE PRESENCE OF HALOGEN-CONTAINING MATERIAL AND TO FORM VOLATILE METAL HALIDE COMPOUNDS AND RECOVERING, AS A PRODUCT COKE PARTICLES WITH A REDUCED METAL IMPURITY CONTENT.