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Rare Earth Mine in the Mojave Desert


Mountain Pass rare earth mine is an open-pit mine of rare earth elements (REEs) on the south flank of the Clark Mountain Range, just north of the unincorporated community of Mountain Pass, and can be seen from Interstate 15 driving to and from Las Vegas. Metals mined from pits like that were used to make the cell phone in your pocket and the computer screen you’re staring at right now.

The mine is owned and operated by Molycorp, and is the only US company that produces the rare earth metals used in devices ranging from wind turbines and electric vehicles to missile-guidance systems and compact fluorescent lightbulbs. There are seventeen rare earth elements, including praseodymium (used to make photographic filters), neodymium (used to make permanent magnets in hard drives and other electronics), and europium (used to make fluorescent light bulbs and TV screens).

Molycorp Mountain Pass Rare Earth Facility, is home to one of the world’s largest and richest deposits of rare earths (including light, mid, and heavy rare earths) The mine has been producing rare earth products for approximately 60 years and has a  line of proprietary rare earth-based water treatment products, including SorbX™ and PhosFIX™.  SorbX™has been used at several water plants to remove contaminants from water including phosphates, from wastewater. 


The Mountain Pass deposit is in a 1.4 billion year old Precambrian carbonatite intruded into gneiss, and contains 8% to 12% rare earth oxides, mostly contained in the mineral bastnäsite. Gangue minerals include calcite, barite, and dolomite. It is regarded as a world-class rare-earth mineral deposit. The metals that can be extracted from it include:





Known remaining reserves were estimated to exceed 20 million tons of ore as of 2008, using a 5% cutoff grade, and averaging 8.9% rare earth oxides.

The Mountain Pass mine dominated worldwide REE production from the 1960s to the 1980s 

The Mountain Pass deposit was discovered by a uranium prospector in 1949, who noticed the anomalously high radioactivity. The Molybdenum Corporation of America bought the mining claims, and small-scale production began in 1952. Production expanded greatly in the 1960s, to supply demand for europium used in color television screens.

The deposit was mined in a larger scale between 1965 and 1995. During this time the mine supplied most of the world wide rare earth metals consumption.The Molybdenum Corporation of America changed its name to Molycorp in 1974. The corporation was acquired by Union Oil in 1977, which in turn became part of Chevron Corporation in 2005.

The mine closed in 2002, in response to both environmental restrictions, lower prices for REEs, and  competition from REEs imported from China. The mine had been mostly inactive since 2002, though processing of previously mined ore continued at the site. In 2008, Chevron sold the mine to privately held Molycorp Minerals LLC, a company formed to revive the Mountain Pass mine. On July 29, 2010, Molycorp, Inc. became a publicly traded firm by selling 28,125,000 shares at $14 in its IPO. The shares trade under the ticker symbol MCP on the NYSE. Molycorp has invested $500 million to reopen and expand the mine. Full mining operations have resumed as a result of increased demand for rare earth metals and China’s decision to restrict exports of REEs and impose export tariffs, both to conserve resources and to give preference to Chinese manufacturers. Molycorp Minerals LLC  is transforming Mountain Pass and creating one of the world’s most technologically advanced, energy efficient, and environmentally friendly rare earth production facilities.

All key production components of the new state-of-the-art rare earth manufacturing complex are now mechanically complete, and they have ramped up production. Molycorp was recently Chosen to Supply Rare Earths for Use in High-Efficiency Siemens Wind Turbine Generators in Colorado.

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