Treatment of platinum-containing catalyst

Claim 1

THE PROCESS FOR THE RECOVERY OF SUBSTANTIALLY PURE PLATINUM FROM PLATINUM-CONTAINING CATALYST, COMPRISING ADMIXING SUCH CATALYST WITH A RELATIVELY SMALL AMOUNT OF CARBON, TREATING SUCH ADMIXTURE WITH STRONG CAUSTIC SOLUTION IN THE LIQUID PHASE AT CONDITIONS INCLUDING TEMPERATURES IN THE RANGE OF 300-500*F. FOR A TIME IN THE RANGE OF 1 HOUR TO 10 HOURS, EFFECTING THE SOLUTION OF SUBSTANTIALLY ALL OF THE CATALYST EXCEPT THE PLATINUM AND THE CARBON WHICH ARE RETAINED AS A RESIDUE, SEPARATING AND RECOVERING SAID RESIDUE, TREATING SAID RESIDUE AT OXIDIZING CONDITIONS TO REMOVE SAID CARBON AND LEAVING A PLATINUM CONCENTRATE, TREATING SAID CONCENTRATE WITH A SOLUTION OF AQUA REGIA TO EFFECT SOLUTION OS SUBSTANTIALLY ALL OF THE PLATINUM WHICH WAS INITIALLY PRESENT IN THE CATALYST, TREATING SUCH PLATINUM-CONTAINING SOLUTION TO CONVERT THE PLATINUM TO CHLORIDE SALT, SEPARATING AND RECOVERING SAID PLATINUM CHLORIDE SALT AND TREATING SAID SALT TO RECOVER SUBSTANTIALLY PURE PLATINUM IN AN AMOUNT SUBSTANTIALLY EQUAL TO THE AMOUNT OF PLATINUM IN THE CATALYST.