Rare Earth metals: Will we have enough?

renewed interest in seabed mining for rare Earth metals. Since the 1960s, scientists have known about the existence of manganese nodules, rocks abundant in water 4,000 to 5,000 meters deep that contain nickel, copper, cobalt, manganese, and rare Earth metals, but in the past, mining them never made economic sense. In 2011 a Japanese team found huge deposits of rare Earth metals, including terbium and dysprosium, in sea mud 3,500 to 6,000 meters deep in the Pacific Ocean. One square kilometer (0.4 square mile) of deposits will be able to provide one-fifth of the current global annual consumption, according to Yasuhiro Kato, an associate professor of Earth science at the University of Tokyo.

The New York Times recently reported the discovery of deposits of gold, silver, copper, cobalt, lead and zinc in the sulfurous mounds that gush hot water from fissures near active volcanic areas on the ocean floor. Seabed mining, however, could cause great damage to fisheries and marine ecosystems, so environmentalists are pushing for more research and mitigation planning before it begins.

As global warming accelerates the melting of the Arctic ice cap, rare Earth metal deposits are becoming accessible and a number of countries are positioning themselves to exploit them.

Then there is the sci-fi-sounding mission of Planetary Resources, a company backed by filmmaker James Cameron and investors Larry Page and Eric Schmidt from Google. It aims to mine the “easily accessible” 1,500 asteroids orbiting Earth, which contain metals such as iron, nickel, cobalt and the platinum group metals used in microprocessors, catalytic converters and renewable energy systems. The company contends that platinum group metals can be found in much higher concentrations on some asteroids than in Earth’s richest mines.

Kelemen believes it will take more than a decade, at least, before there is commercially significant extraction of rare Earth metals from seabed manganese nodules or asteroid mining, and that sulfurous mound mining would not alleviate the neodymium shortage. So what other solutions exist?

“I would like to see more exploration and research to make sure we know what’s there and what the challenges are of going after it,” said Graedel. “I don’t think we know if we’ll have the resources to meet future demand.” He also wants material scientists to aim their product design and lab investigations at the most common elements, rather than the scarcer ones. Some companies, including GE, Toyota, and Ford, are trying to use less rare Earth metals in their products, limit waste, and develop substitute metals.

Though recycling e-waste cannot satisfy the rapidly growing demand for rare Earth metals, it is one way to help alleviate the shortage. Recycling and reusing materials also saves the energy used in mining and processing, conserves resources, and reduces pollution and greenhouse gas emissions. The U.S. Environmental Protection Agency reports that in 2009, 2.37 million tons of electronics were discarded, but only 25 percent was recycled. The European Union recently enacted new e-waste recycling rules requiring member states to recycle 45 percent of all electronic equipment sold starting in 2016, rising to 65 percent by 2019 (find out where you can recycle your e-waste).

Ironically, as prices for electronic products come down, people tend to buy more and more of them, so demand for rare Earth metals keeps rising.

“In the 21st century, we are facing a lot of resource issues — energy, water, food and metals,” said Graedel. “Ultimately each individual consumer is driving the whole rate of expansion of resource use…do we really need all this stuff?”

— Read more in Rare Earth Elements: The Global Supply Chain (Congressional Research Service, 8 June 2012); “Clean energy could lead to scarce materials” (MIT release, 9 April 2012); and Elisa Alonso et al., “Evaluating Rare Earth Element Availability: A Case with Revolutionary Demand from Clean Technologies,” Environmental Science and Technology 46, no. 6 (3 February 2012): 3406–414 (DOI: 10.1021/es203518d)