Rare Earth metals: Will we have enough?

the heavy rare Earth metal dysprosium, used to increase the longevity of magnets in wind turbines and electric cars, is harder to find. “Ninety-nine percent of the current supply comes from clay deposits that can be easily mined with a shovel in Jiangxi, China,” Kelemen said. “Other known deposits of dysprosium in Canada and Greenland will be much harder to mine.”

To ease the bottleneck of rare Earth metals, mines being developed in Australia, Brazil, Canada, and Vietnam could be in production within five years. The Molycorp mine in Mountain Pass has reopened and expects to be operating at full capacity this year.

More mining of rare Earth metals, however, will mean more environmental degradation and human health hazards. All rare Earth metals contain radioactive elements such as uranium and thorium, which can contaminate air, water, soil and groundwater. Metals such as arsenic, barium, copper, aluminum, lead and beryllium may be released during mining into the air or water, and can be toxic to human health. Moreover, the refinement process for rare Earth metals uses toxic acids and results in polluted wastewater that must be properly disposed of. The Chinese Society of Rare Earths estimated that the refinement of one ton of rare Earth metals results in seventy-five cubic meters of acidic wastewater and one ton of radioactive residue. The 1998 leak of hundreds of thousands of gallons of radioactive wastewater into a nearby lake was a contributing factor to Molycorp’s shutdown in 2002. Many new mines, including Molycorp, are now developing more environmentally friendly mining techniques.

Nevertheless, we are mining poorer and poorer ores all the time, and it takes more and more energy to extract the same amount of metal, according to Graedel. “I’m not worried that we’ll run out of rare Earth metals, but will we have enough energy at a reasonable price to extract it?” he asked.

The high performance of our products depends on the specific rare Earth metals they utilize; unless there are technological breakthroughs, doing without those materials would force products to revert to old performance standards. “I’m worried that things will become so scarce and expensive that we can’t routinely use them as part of modern industrial design,” said Graedel. There could come a point when the cost of extracting rare Earth metals is simply not economically justifiable, no matter how high their prices rise.

The release notes that because of rising prices, there is now