summer 2011 Rare Earth Elements for Emerging Technologies Before 2010 most Americans had never Where Are Rare Earth Elements heard of rare earth elements, except maybe Found? in high school chemistry class when studying the periodic table of elements. Commercial deposits of valuable rare earth However, in April 2010 China announced elements are not evenly distributed around that it would impose export quotas on the world. They tend to be concentrated in rare earth elements immediately, in order specific localities based on favorable geo- to address internal environmental issues logic conditions. Currently more than 95 at their mines, regulate illegal mining percent of the rare earth elements required operations, and provide for a sustainable for emerging technologies is obtained rare earth element production and supply from mines in China. Rare earth elements for China. This announcement triggered an are not found naturally as pure metallic increase in price and some panic buying. elements. Instead, they are incorporated In late September 2010 China halted in hundreds of minerals, but only a few exports of rare earth elements to Japan, Monazite (in red), a rare earth mineral. From a minerals are economically important. Bast- following an international dispute over pegmatite in the Petaca mining district in northern nasite, a carbonate mineral, and monazite, New Mexico. Photo by Leo Gabaldon. territorial fishing rights. Japan uses rare a phosphate mineral, are the most eco- earth elements in their highly profitable nomically important rare earth minerals in are commonly divided into two chemical electric/hybrid automobiles and many the world at this time. Most of the world’s groups: the more abundant light rare earth electronic consumer products. Although largest concentrations of bastnasite are in elements (lanthanum through europium) China reinstated exports to Japan in early carbonatites, igneous rocks that contain and the lesser abundant heavy rare earth November 2010, this incident placed rare more than 50 percent carbonate minerals. elements (gadolinium through lutetium, earth elements in headlines and on the lips Carbonatites are found as dikes, sills, plugs, and yttrium and scandium). They are of resource planners, politicians, investors, lava flows, and large stocks. Rare earth important because of their uniquely and journalists throughout the world. elements also may be concentrated in peg- efficient electronic properties, including matites and granitic intrusions or as placer What Are Rare Earth Elements the ability to readily give up or accept elec- deposits. Each ore deposit is different, and trons, a property useful for magnets, optics, a detailed understanding of the mineralogy and How Are They Used? electronics, and other applications. and chemistry, as well as an understanding Rare earth elements are some of the Rare earth elements are lithophile ele- of the lithology, structure, and alteration more important commodities required ments (or elements enriched in the crust) of the deposit are required to determine to manufacture products associated with that have similar physical and chemical economic potential. emerging green technologies, including properties, and, therefore, occur together Between 1950 and 1964 monazite placer wind turbines and hybrid/electric cars. in nature. The name is misleading; their deposits in South Africa and elsewhere sup- They are essential in most of our electronic content in the earth’s crust ranges from plied the small amounts of rare earth ele- devices, including cell phones, laptops, 60 ppm (parts per million) for cerium ments needed. From 1965 to 1998, most iPods, computer chips, etc. Other tech- to approximately 0.5 ppm for terbium of the rare earth elements were produced nologies are being developed that require and lutetium, which is greater than the from the large Mountain Pass mine in Cal- rare earth elements in their manufacture, crustal abundance of silver. Four of them ifornia, from carbonatites similar to those technologies used in water purification, (yttrium, lanthanum, cerium, and neo- now being mined in China. Rare earth desalination, magnetic refrigeration, and dymium) have larger crustal abundances elements also are produced from igneous more energy-efficient light bulbs. The than lead. However, they are not always rocks on the Kola Peninsula in Russia, clay so-called rare earth elements include the concentrated in easily mined economic deposits in China, heavy mineral sands 15 lanthanide elements (atomic numbers deposits, and only a few deposits in the (placer deposits) in India and Brazil, and as 57–71), yttrium, and scandium. They world account for current production. a byproduct of tin production from mines Published by the New Mexico Bureau of Geology and Mineral Resources • A Division of New Mexico Tech 1 2 ATOMIC ATOMIC H He ELEMENT SYMBOL 3 4 5 6 7 8 9 10 NUMBER WEIGHT Li Be B C N O F Ne Lanthanum La 57 138.9 11 12 13 14 15 16 17 18 Na Mg Al Si P S Cl Ar Cerium Ce 58 140.1 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 Praseodymium Pr 59 140.9 K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr Neodymium Nd 60 144.2 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe Promethium Pm 61 145 55 56 57 * 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 Samarium Sm 62 150.4 Cs Ba La Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn 87 88 89 104 105 106 107 108 109 110 Europium Eu 63 152.0 Fr Ra Ac Unq Unp Unh Uns Uno Une Unn Gadolinium Gd 64 157.3 * 58 59 60 61 62 63 64 65 66 67 68 69 70 71 Terbium Tb 65 158.9 Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu Dysprosium Dy 66 162.5 90 91 92 93 94 95 96 97 98 99 100 101 102 103 Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr Holmium Ho 67 164.9 Erbium Er 68 167.3 The periodic table of the elements, with the 15 lanthanide elements shown in Thulium Tm 69 168.9 gray. Two related elements, scandium and yttrium are shown in green. Together these comprise the so-called rare earth elements. Atomic numbers and atomic Ytterbium Yb 70 173.0 weights for each of these 17 elements are shown in the table on the right. Lutetium Lu 71 175.0 RELATED ELEMENTS Scandium Sc 21 45.0 Yttrium Y 39 88.9 in Malaysia. Smaller deposits in Indonesia, found in the Peas Ridge iron mine in are found in vein deposits. Bastnasite was the Commonwealth of Independent States Missouri, and production from the tailings produced from the Gallinas Mountains (12 countries, including Russia, formerly there could provide a source in the near in the 1950s as a byproduct of fluorite part of the Soviet Union), Nigeria, North future. Rare earth elements are also found production. Strategic Resources, Inc., has Korea, and Vietnam sometimes produce in phosphorite deposits in the southeastern completed drilling the carbonatites in the small quantities. In the future other U.S. along the Atlantic Coastal Plain from Lemitar Mountains in Socorro County and deposits throughout the world may provide North Carolina to the center of the Florida is awaiting final test results before proceed- sources, including uranium deposits in Peninsula. ing further. Geovic Mining Corporation Australia, Canada, and Kazakhstan. has staked claims in the Cornudas Moun- tains in the Otero Mesa area in southern Where in the U.S. New Mexico and applied Are Rare Earth 150 for drilling permits. BE Elements Found? Resources, Inc., has drilled at Apache Warm Springs 120 Rare earth elements were on the Sullivan Ranch in produced from pegmatites Socorro County, where in the U.S., including 90 they found anomalous New Mexico, before 1950. concentrations of rare earth California’s Mountain elements associated with Pass mine began produc- 60 China beryllium vein deposits. tion of rare earth elements Claims have been staked in 1952 but closed in in kilotons Production in the Caballo and Burro 2002 because of environ- 30 USA Mountains where rare earth mental problems and the Other elements are found in vein availability of cheaper 0 deposits and in igneous supplies of rare earth 1950 1960 1970 1980 1990 2000 2010 rocks. Deposits of yttrium elements from China. and zirconium are found Molycorp, Inc., plans to Global production of rare earth elements, in kilotons, from 1950 through 2010. Data from the U.S. Geological Survey. in igneous rocks at Pajarito reopen the Mountain Pass Mountain in the north- mine in 2012 to provide eastern Mescalero Apache a domestic source to meet the growing Where in New Mexico Are Rare Indian Reservation, south of Ruidoso. demand for rare earth elements. Earth Elements Found? Although Molycorp, Inc., reported Other areas in the U.S. have unde- Rare earth elements are found throughout recoverable resources of 2.7 million short veloped deposits of rare earth elements, New Mexico, and several areas are tons grading 0.18 percent yttrium and 1.2 mostly in igneous rocks, including deposits undergoing current exploration. Strategic percent zirconium in 1990, the Mescalero at Bokan Mountain in Alaska, Lemhi Pass Resources, Inc., plans to drill in the Apache Indian Nation is not interested in in Idaho, and the Bear Lodge Mountains Gallinas Mountains in Lincoln County developing these deposits at this time. in Wyoming. Rare earth elements are this summer, where rare earth elements new mexico earth matters 2 summer 2011 New Mexico mines were ting process can take as long as Farmington La Cueva Stinking Hopewell producing rare earth elements Bromide No.