102 • Marine Minerals: Exploring Our New Ocean Frontier 



Platinum-Group Metals 

 Properties and Uses 



The platinum-group metals (PGMs) consist of 

 six closely related metals that commonly occur to- 

 gether in nature: platinum, palladium, rhodium, 

 iridium ruthenium, and osmium. ^^ They are not 

 abundant metals in the earth's crust; hence their 

 value is correspondingly high. At one time, nearly 

 all of the platinum metals were used for jewelry, 

 art, or laboratory ware but during the last 30 or 

 40 years they have become indispensable to indus- 

 try, which now consumes 97 percent of the PGMs 

 used annually in the United States. 



Industry uses PGMs for two primary purposes: 

 1) corrosion resistance in chemical, electrical, glass 

 fiber, and dental-medical applications, and 2) a 

 catalysis for chemical and petroleum refining and 

 automotive emission control. About 46 percent of 

 PGMs was used for the automotive industry in 

 1986, 18 percent for electronic applications, 18 per- 

 cent for dental and medical uses, 7 percent for 

 chemical production, and 14 percent for miscellane- 

 ous uses.^^ Although the importance of platinum 

 for jewelry and art has diminished as industrial uses 

 increase, a significant amount of the precious metal 

 is retained as ingots, coins, or bars by investors. 



While the PGMs are often referred to collectively 

 for convenience, each has special properties. For 

 example, platinum-palladium oxidation catalysts 

 are used for control of auto emissions, but a small 

 amount of rhodium is added to improve efficiency. 

 Palladium is used in low-voltage electrical contacts, 

 but ruthenium is often added to accommodate 

 higher voltages.'" 



National Importance 



The United States is highly import-dependent 

 for PGMs. About 98 percent of PGMs consumed 

 in 1986 were imported. The Republic of South 



^^The disparities in demand among PGMs and the variance in 

 proportion and grade of individual metals recovered from PGM 

 mineral deposits complicate the assessment of supply-demand for this 

 metal group. For simplicity, the PGMs are discussed as a unit. 



™J. Loebenstein, "Platinum-Group Metals," Mineral Commodity 

 Summaries— /987 (Washington, DC: U.S. Bureau of Mines, 1987), 

 p. 118. 



'"J. Loebenstein, "Platinum-Group Metals," Mineral Facts and 

 Problems— 1985 Edition, Bulletin 675 (Washington, DC: U.S. Bu- 

 reau of Mines, 1986), p. 599. 



Africa supplied 43 percent of U.S. consumption, 

 United Kingdom 17 percent, U.S.S.R. 12 percent, 

 and Canada, Colombia and other sources 28 per- 

 cent. Because nearly all of the PGMs imported from 

 the United Kingdom originated in South Africa 

 prior to refining, the Republic of South Africa ac- 

 tually provides the United States with approxi- 

 mately 60 percent of its platinum imports. 



Potential instability in southern Africa, depen- 

 dence on the U.S.S.R. for a portion of U.S. sup- 

 ply, scarcity of domestic resources, and the impor- 

 tance that PGMs have assumed in industrial goods 

 and processes make platinum metals a first tier crit- 

 ical and strategic material. '' Platinum, palladium, 

 and iridium are retained in the National Defense 

 Stockpile (table 3-10). 



Domestic Resources and Reserves 



There are several major areas with PGM deposits 

 that are currently considered to be economic or 

 subeconomic in the United States. The domestic 

 reserve base is estimated to be about 16 million troy 

 ounces.'^ Of that, however, only 1 million ounces 

 are considered to be reserves .^^ Most of the PGM 

 reserves are byproduct components of copper re- 

 serves. Demonstrated resources may contain 3 mil- 

 lion ounces of platinum of which 2 million ounces 

 are gauged to be recoverable.'* Some estimates 

 place identified and undiscovered U.S. resources 

 at 300 million ounces.'* 



"Office of Technology Assessment, Strategic Materials: Technol- 

 ogies to Reduce U.S. Vulnerability, p. 52. 



'^Loebenstein, "Platinum-Group Metals," Mineral Commodity 

 Summaries — 1987, p. 119. 



"Ibid., p. 21. 



"T. Anstett, D, Bleiwas, and C. Sheng-Fogg, Platinum Availabil- 

 ity—Market Economy Countries, IC 8897 (Washington, DC: U.S. 

 Bureau of Mines, 1982), p. 4. 



"Ibid., p. 6. 



Table 3-10.— Platinum-Group Metals in the National 

 Defense Stockpile (as of Sept. 30, 1986) 



Inventory as 

 Material Goal Inventory percent of goal 



(thousand troy ounces) 



Platinum 1,310 440 34 



Palladium 3,000 1,262 42 



I ridium 98 30 30 



^Ttie Stockpile also contain 13,043 troy ounces of nonstockpile-grade platinum 

 and 2,214 ounces of palladium. 



SOURCE: J.R. Lobenstein, "Platinum-Group Metals," Mineral Commodity Suin- 

 maries—)9S7 (Wastiington, DC: U.S. Bureau of Mines, 1987), p. 119, 



