Rare Earths Common In United States
Industrial minerals article by Harold Hough
Approximately 13 million metric tons of rare earth elements (REE) exist within known deposits in the United States, according to the first-ever nationwide estimate of these elements by the U.S. Geological Survey. The report describes significant deposits of REE in 14 states, with the largest known REE deposits at Mountain Pass, Calif.; Bokan Mountain, Alaska; and the Bear Lodge Mountains, Wyo. Additional states with known REE deposits include Colorado, Florida, Georgia, Idaho, Illinois, Missouri, Nebraska, New Mexico, New York, North Carolina, and South Carolina
This is good news since the Chinese, who produce about 96% of the world’s REEs, are beginning to restrict exports in order to give its high tech manufacturers an edge in the international market. However, that is changing. Molycorp, the owner of the Mountain Pass Mine is modernizing and expanding the operations so it will be producing about 20,000 tons of rare earth ores by 2012. Mountain Pass is the world’s largest developed deposit mined exclusively for rare earths.
Rare Earth Elements are relatively unknown to the average person. Names like europium, praseodymium, neodymium, lanthanum, samarium, cerium and gadolinium rarely get mentioned in chemistry classes, much less normal conversation. Although called “Rare Earths,” they are abundant in the Earth’s crust. It was the fact that they were hard to extract and purify that led early scientists to think they were rare. Before World War Two, the world’s supply of many of these elements was measured in grams and merely laboratory curiosities. And, the lack of samples guaranteed that scientists didn’t spend much time studying their properties.
The growth in electronics in the post WW II age changed all that. Today REEs are critical for optics and electronics. Europium, for instance provides the red phosphor in color cathode-ray tubes and liquid crystal displays used in computers and televisions. There is no known substitute. And, the powerful magnets made with neodymium are critical for many miniaturized electronics, including high capacity disk drives and DVD players. Even your outdoor grill relies upon cerium to light the propane.
For years, the United States was self sufficient in the mining of REE thanks to the Mountain Pass deposits which were discovered in the 1949. Two prospectors were looking for uranium deposits, when their Geiger counter detected high radioactivity in a rock outcropping. The prospectors staked a claim and sent off ore samples. When the assay results came back, they discovered that they had discovered a worthless mineral called bastnaesite. The claims ended up in the hands of MolyCorp after the USGS carried out additional surveys in the 1950s.
Mountain Pass was developed at a critical time. By the 1960s color televisions were finding their way into every American household and europium was critical for their television tubes. As the mine developed more efficient solvent extraction processes to extract europium, they produced in turn more REEs, which allowed scientists to find new uses for them. Many of these new applications were in defense industries.
For the next generation, Mountain Pass was the major source for rare earths for the world. However the increased demand for them caused geologists to find new deposits for them, especially in China, which soon became the major rare earth producer. By 2000, 90% of all the REEs used in the US came from China. Currently, the US uses about $1 billion in REEs a year.
But, China wasn’t just a rare earth producer. It has also focused on finding new applications for REEs and is now a rare earth technology leader. REEs are critical to several defense technologies and American military leaders are uncomfortable with China’s lead in this critical technology. Karl A. Gschneidner Jr., a senior metallurgist at the U.S. Department of Energy's Ames Laboratory, recently cautioned members of a Congressional panel that "rare-earth research in the USA on mineral extraction, rare-earth separation, processing of the oxides into metallic alloys and other useful forms, substitution, and recycling is virtually zero."
But, now China is finding its demand for REEs greater than its supply. China is preparing to build 330 giga-watts worth of wind generators. That will require about 59,000 tons of neodymium to make high-strength magnets -- more than that country's annual output of neodymium. Since China is the major supplier of REEs like neodymium, experts expect it will have little or none to export if it moves ahead with its wind power plans.
The Mountain Pass modernization is geared to meet worldwide demand in the face of Chinese export cutbacks. Operation Phoenix, which the modernization plans is called, begins in January 2011 and sees more extensive expansion than originally planned. While the original plan called for modernizing the current mill, Molycorp realized that REE demand required a new mill. The new mill will be able to produce up to 40,000 tons, which is twice what production is currently planned for.
Since current US demand for rare earths is about 10,000 tons a year, the Mountain Pass operation promises to become a major export product for the United States, especially if the Chinese continue to restrict REE exports. It may not signal America’s return to the status of top REE producer, but it does provide a secure supply for American manufacturers.