PURPOSE: To efficiently recover group VIII noble metals from tar by adding methyl iodide to a mixture composed of the group VIII noble metals and tar, hermetically sealing this mixture into a vessel and heating the mixture to a specific temp. to form the group VIII noble metals into a solid form.

CONSTITUTION: The methyl iodide (b.p. 42.4°C) is added to the mixture composed of the group VIII noble metals formed by a carbonylization process and the tar and the mixture is supplied to the vessel. The inside of the vessel is insulated from outside and the vessel is heated to heat the content to ≥50°C, more preferably about 120 to 180°C to allow the group VIII noble metals to settle as the solid. This mixture is cooled down to about <75°C and is filtered to separate the solid group VIII noble metals from the tar and the methyl iodide. As a result, the group VIII noble metals are efficiently recovered.