The platinum group metals (PGM) comprise platinum (Pt), palladium (Pd), iridium (Ir), osmium (Os), rhodium (Rh) and ruthenium (Ru). Of these, only palladium, platinum and to some extent, rhodium are commercially important. Platinum is a silvery grey metal, heavy than ductile and highly ductile. Its concentration in Earth's crust is about 5 parts per billion (ppb), by weight. Palladium (5 ppb) and rhodium (1ppb) are harder and lighter than platinum. All members of the group are generally highly resistant to corrosion and heat. The platinum group elements form a comprehensive range of platinum group minerals, including sulphides, arsenides, tellurides, alloys and native metals.

The proportion of platinum and palladium group metals used in various applications may vary significantly from year to year. This may be due to the fluctuations in the prices of two metals, and from region to region. In 2002, the primary uses of platinum, the world across, were in jewelry (43.27%) and auto catalysts (40%). While the jewelry proportion was higher in Japan (54%) and China, and auto catalysts use was higher in W. Europe (71%) and North America. Other applications were in chemical industry, primarily as a catalyst, electrical uses, glass and petroleum refining.

Palladium was mainly used in auto catalysts (64.4%), again with higher proportions in W. Europe (70%) and North America. Other applications were electronics (15%), dental use (16%), chemical industry and jewelry. Rhodium was primarily used in auto catalysts (98.7%). Some other uses were in chemical, glass and electrical industries.

Types / Grades
Different grades, varieties and types of platinum group metals scrap is used to recover pure metal from the scrap. Given in the table below are some of the important grades / types of platinum group metals used in recycling -

Grade Details Platinum Scrap It consists of platinum alloy or remelted platinum scrap. This grade should be assayed and sold based on the platinum content as agreed upon between the seller and buyer. Plated Platinum Scrap T^his grade of scrap includes electroplated or roll plated platinum coated scrap. It should be assayed and sold based on the platinum content as agreed upon between the seller and buyer. Palladium Scrap It comprises of palladium alloy or remelted palladium It should be assayed and sold based on the platinum content as agreed upon between the seller and buyer. Plated Palladium Scrap Plated palladium scrap includes electroplated or roll plated palladium coated scrap. It should be assayed and sold based on the palladium content as agreed upon between seller and buyer. Rhodium Scrap This grade of scrap consists of platinum alloy or remelted rhodium scrap. It should be assayed and sold based on the rhodium content as agreed upon between the seller and buyer.   Plated Rhodium Scrap It includes roll plated or electroplated rhodium coated scrap. The material should be assayed and sold based on the rhodium content as agreed upon between the seller and buyer. Catalytic Converters Catalytic Converters comprise whole scrap automotive catalytic converters, trimmed of excess pipe. The material should be intact and contain all of the original catalyst material. Pellet Catalyst It consists of un-treated pellet style catalyst retrieved from automotive catalytic converters> It should be dry and contain the platinum group metal coating. Honeycomb Catalyst This grade of scrap consists of un-treated honeycomb style catalyst recovered from automotive catalytic converters. The material must be dry and contain platinum group metal coating. Other Platinum Group Scrap It may contain assorted platinum group metals content and those which are not included in the listed grades.

Platinum Group Metals Scrap Recycling - Associations

• Bureau of International Recycling
• Canadian Association of Recycling Industries (CARI)
• Curbside Value Partnership
• Minerals, Metals & Materials Society (TMS)

Platinum Group Metals Scrap Recycling - Publications

• Recycling International Magazine