Michele Kearney's Nuclear Wire: US Faces Substantial Obstacles to Increasing Rare Earths Production

Saturday, October 30, 2010

US Faces Substantial Obstacles to Increasing Rare Earths Production

Reader James S. highlighted a useful article at the MIT Technology Review, “Can the U.S. Rare-Earth Industry Rebound?” Our only quibble to this solid piece is its summary, which underplays some critical aspects of the article:

The U.S. has plenty of the metals that are critical to many green-energy technologies, but engineering and R&D expertise have moved overseas.

In fact, the while the article does discuss US versus foreign engineering expertise in rare earths mining, it describes in some detail how difficult rare earths mining is in general (more accurately, not the finding the materials part, but separating them out) and the considerable additional hurdles posed by doing it in a non-environmentally destructive manner. Thus the rub is not simply acquiring certain bits of technological know-how, but also breaking further ground in reducing environmental costs.
And this issue has frequently been mentioned in passing in accounts of why rare earth production moved to China in the first place. It’s nasty, and advanced economies weren’t keen to do the job. China was willing to take the environmental damage. For instance, the New York Times points out:

China feels entitled to call the shots because of a brutally simple environmental reckoning: It currently controls most of the globe’s rare earths supply not just because of geologic good fortune, although there is some of that, but because the country has been willing to do dirty, toxic and often radioactive work that the rest of the world has long shunned.

From the MIT Technology Review:

Getting from rocks to the pure metals and alloys required for manufacturing requires several steps that U.S. companies no longer have the infrastructure or the intellectual property to perform….
In the 1970s and 1980s, the Mountain Pass mine in California produced over 70 percent of the world’s supply. Yet in 2009, none were produced in the United States, and it will be difficult, costly, and time-consuming to ramp up again…
The two mines that will be stepping up production soonest are Mountain Pass, being developed by Molycorp, and the Mount Weld mine, which is being developed by Lynas, outside Perth, Australia. Mountain Pass has the edge of already having been established. But the company cannot use the processes used in the mine’s heyday: they’re both economically and environmentally unsustainable.
Several factors make purification of rare earths complicated. First, the 17 elements all tend to occur together in the same mineral deposits, and because they have similar properties, it’s difficult to separate them from one another. They also tend to occur in deposits with radioactive elements, particularly thorium and uranium. Those elements can become a threat if the “tailings,” the slushy waste product of the first step in separating rare earths from the rocks they’re found in, are not dealt with properly…
Mountain Pass went into decline in the 1990s when Chinese producers began to undercut the mine on price at the same time as it had safety issues with tailings. When the Mountain Pass mine was operating at full capacity, it produced 850 gallons of waste saltwater containing these radioactive elements every hour, every day of the year. The tailings were transported down an eleven-mile pipeline to evaporation ponds. In 1998, Mountain Pass, which was then owned by a subsidiary of oil company Unocal, had a problem with tailing leaks when the pipeline burst; four years later, the company’s permit for storing the tailings lapsed.
Meanwhile, throughout the 1990s, Chinese mines exploited their foothold in the rare-earth market. The Chinese began unearthing the elements as a byproduct of an iron-ore mine called Bayan Obo in the northern part of the country; getting both products from the same site helped keep prices low initially. And the country invested in R&D around rare-earth element processing, eventually opening several smaller mines, and then encouraging manufacturers that use these metals to set up facilities in the country.

Yves here. I’d be curious for input on this point from any informed readers. China has allegedly made R&D advances, but are these processes aimed at increased efficiency? If so, they’d give China a cost advantage, but not contend with environmental issues; indeed, it’s conceivable that the toll with these new processes is even worse. Back to the article:

By 2012, Molycorp expects to produce 20,000 tons a year, and under its current mining permits could double capacity to 40,000 tons. Sims also says the company will produce rare-earth products at half the cost of the Chinese in 2012. According to the company, these savings will be made possible by several changes, such as eliminating the production of waste saltwater. Molycorp will use a closed-loop system, converting the waste back into the acids and bases required for separation and eliminating the need to buy such chemicals. The company will also install a natural-gas power cogeneration facility onsite to cut energy costs.
But Ames Lab’s Geschneidner notes that one major source of cost in the separation process can’t be eliminated–the fact that it simply takes a long time. Milled rock is shaken again and again in a mixture of solvents to separate the elements by weight; depending on the ultimate purity that’s required, this must be done 10,000 to 100,000 times. The result is then sold as a concentrate or treated to produce rare-earth metal oxides.
Even if Molycorp does succeed in reducing the costs of separation by half, the next step in production may cause a hiccup. Rare-earth oxides and concentrates do have a market, for example as catalysts for the petroleum industry, but they can’t be made into magnets. To make magnets, rare-earth oxides must first be converted into pure metals, a process that produces caustic byproducts, and is done solely in China today. Sims says that Molycorp is investigating pathways that are environmentally friendly and aren’t covered under intellectual property owned by foreign companies. These metals must next be made into alloys suitable for the magnets, another capability that’s concentrated overseas, mostly in Japan and Germany.

The story is not quite as dire as one might conclude from this article, which focuses strictly on the US mining question. The US is not the only country looking to gear up its rare earth production. Rare earths can be extracted from used products, particularly cars. And some products can be designed to eliminate the use of rare earths, although the tradeoff is typically more bulk and weight. Nevertheless, it is clear that advanced economies will need to make a lot of adjustments, including more investments in R&D and product design, to contend with the challenge of rising demand versus constrained supplies of rare earths.