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Posts Tagged ‘rare earths’

Theirs is the first so-called switched reluctance motor with this kind of torque density, they say, though the researchers admit that it’s still not equivalent to the torque and efficiency produced by motors with permanent magnets. Simply, switched reluctance motors tap magnetic reluctance--it’s like electrical resistance, but for magnetism--in an electromagnetic coil. By turning the electricity on and off within the coil, a rotor inside is induced to spin, creating rotary motion/force (this is explained visually in the video below).

Switched reluctance motors have their drawbacks, particularly because they can be difficult to control. But better onboard, real-time computing is making them more reliable and less prone to vibration and noise. Moreover, the Tokyo team’s motor is about the size of the engine that goes in a Prius, meaning that it’s been scaled to a form that will fit in a standard small-sized production car.

But most importantly, it means Japan may be a few design tweaks away from having an electric engine that doesn’t hinge on trade relations with the Chinese, who have been accused (not least by the Japanese) of bogarting their supply of rare earths (China controls 95-97 percent of global supply, depending on who you ask). And as far as what it means to you, the development of a dependable switched rotor engine with decent power and torque could lower the cost of EVs.

[PhysOrg]

Rare earths--in case you missed last year’s high-tech sector fears and China’s short-lived unofficial “embargo” that rattled some Japanese and Western industries--are a group of metals that are integral to several cutting-edge technologies, including batteries, green technologies like wind turbines, and next-gen military technologies. They’re also used in lots of everyday technologies that are vital to developed economies, things like smartphones and computer monitors.

In short, the world needs rare earths and as developing economies continue their rapid upward climbs the world will need even more of them. Currently China controls 97 percent of the world’s usable supplies, and that’s been a source of tension as Chinese leaders have scaled back exports to protect industries at home. So the idea that there are perhaps hundreds of billions of tons of untapped rare earths lying in international waters is huge.

But that’s just the first of many angles to this story. For instance, how do we get to the minerals? The two sites named by the Japanese researchers are near Tahiti and Hawaii in international waters ranging from 11,500 to 20,000 feet. Deep sea mining of manganese (and copper and nickel) is already underway in the Pacific, and so some of the technology there might be applicable, as might some of hardware being developed by oil and gas explorers seeking to tap deeper and deeper energy reserves.

Next, there are environmental concerns. The fact that these reserves are in international waters could complicate regulation of any undersea mining activities, and ocean floor ecosystems could be disrupted by the dredging of huge swaths of the seabed.

Then there’s the question of whether undersea mining of rare earths is commercially viable? It may be that getting to these seabed deposits is so expensive as to be prohibitive. Or the discovery might lead to the development of entire fleets of seafloor mining robots. Whatever the future developments may be, the immediate impact is limited: China’s grip on the rare earths market is no less strong today as it was yesterday, and it’s not likely to change in the foreseeable future.

[BBC, New Scientist]

The electronic future is buried under the ground in Missouri

A chunk of magnetite guards the office door at the Pea Ridge iron mine near Sullivan, Mo., a mascot of the mine’s past and future. When Jim Kennedy bought the mine in 2001, he’d planned to restart production on a high-grade iron ore deposit. He didn’t realize he was sitting on a mother lode of 600,000 metric tons of high-grade rare earth elements -- elements the U.S. is desperately hungry for. Four years ago, he almost threw away reams of documents describing Pea Ridge’s deposit. “Nobody bothered to tell me about it,” he said.

At present, the U.S. is almost totally reliant on China for rare earth elements, which are used to make lasers, guided missiles, efficient batteries, and other technologies of the future. But China has recently slashed its exports of these materials, promising new regulations over their production, while raising prices — and the hackles of numerous national governments. As scientists work on possible alternatives to rare earths, some think renewed domestic production of the minerals could loosen China’s grip over 95 percent of the world’s rare earth supply.

Right now, the Pea Ridge mine is a quiet, muddy place with rusting mills, storage sheds cluttered with cracked core samples, and a marshy lake full of mine tailings. But when it’s renovated and reopened, Kennedy hopes to become only the second rare earth producer in the western hemisphere. He envisions a bustling mine producing billions of dollars of rare earths, feeding the renewable energy and defense industries. He has a few hurdles to clear before that dream becomes reality.

Rare earths are recovered just like other metals — from rocks removed from the ground that are broken up, milled and processed into purified forms. It’s a water-intensive, toxic process, but Kennedy says his mine has plenty of rare earths in the mile-long, 100-foot-deep lake of tailings, a slurry-like waste byproduct of almost 40 years of iron mining. He aims to start mining the lake’s 22 million tons of waste by the end of the year and restart underground mining in 2012.

On the frigid day I visited, Kennedy took me to Pea Ridge’s core room, a metal shed stuffed with stacks of long, thin cardboard boxes. Inside each box is a section of a core sample taken when the mine was first developed. The one-inch-diameter cylindrical rocks helped Bethlehem Steel, the original owner, determine what the mine had to offer. Back in the 1960s, however, they were only interested in iron. Kennedy pulled out a broken piece and held a magnet to it, and it stuck — a chunk of magnetite, just like the front office sentinel. Another slice of rock was embedded with some glinting yellowish speckles. Those could be bits of rare earth oxides, he said.

Kennedy aims to resume the mine's production of iron, but to produce rare earths as a byproduct of iron purification. That’s possible due to the way the metals are situated in the earth.

The iron ore is criss-crossed with breccia pipes, a mass consisting of broken sedimentary rock infused with intriguingly named minerals like xenotime and monazite. The rare earths are part of those minerals. "The entire system is flooded with rare earths," Kennedy said.

The phosphorus in these minerals must be removed if their iron is to be used, but it turns out that’s a good thing for rare earth production. The rock is crushed into a fine powder and added to a pine oil solution to produce a frothy liquid. The phosphorus and the rare earths float out, separating them from the high-grade iron.

When it starts production, Pea Ridge would follow California’s Mountain Pass mine, becoming only the second American producer of rare earths. Molycorp Inc. started work at Mountain Pass in December, the mine’s first activity since 2002, when it closed amid regulatory problems stemming from a wastewater spill. Mountain Pass now produces about 3 percent of the world’s rare earth supply, and Molycorp hopes to increase that to 25 percent, producing 40,000 metric tons a year by 2013.

Mountain Pass will be the country’s leading rare earth mine, but it won’t be able to produce many of the so-called heavy rare earths, like dysprosium, which is used to make computer memory and lasers. One analyst suggested this week that Molycorp should diversify by buying up companies with claims on heavy rare earth deposits. Pea Ridge has them in abundance, according to the U.S. Geological Survey.

Despite their name — a holdover from the 1800s and early 1900s — rare earths aren’t particularly rare; they’re much more common than gold, and some are nearly as common as lead. They’re found in relatively low concentrations, however, requiring the processing of lots of rock. Ten states are known to have significant rare-earth deposits, according to a 2010 study by the USGS. Most are in the western U.S., but the Pea Ridge deposit has the highest grade of any site in the country, averaging 12 percent rare earth oxide concentration. Mountain Pass has much more tonnage, but at an average of only 8 percent concentration (and the vast majority is “light” rare earths).

Given its resources and existing infrastructure, why isn't Pea Ridge already producing rare earths? There’s a catch. Along with iron, the heavy rare earths at Pea Ridge are found intermingled with thorium, a radioactive element that requires special processing and cleanup. Hoping to turn this into a positive, Kennedy is drumming up support for thorium as an alternative energy source, namely powering molten salt reactors that could be scattered throughout cities. “When you mine for rare earths, you get the thorium for free,” he said.

Kennedy, a former Army Special Forces soldier and investment banker, has become an outspoken evangelist for rare earths and thorium, speaking to members of Congress, mining groups and engineers — he just gave a presentation at Oak Ridge National Laboratory — about the problem of Chinese dominance and the potential for American resurgence. He is pressing lawmakers in Missouri and Washington to establish a public-private cooperative to come up with $1 billion to build a rare earth refinery in Missouri, and he is hoping to spur a new thorium energy industry.

For now, his plans center on iron production. He wants to build a pipeline to ship iron ore to the Mississippi River 44 miles to the east, where he already has a permit for a processing facility and barge port. Pea Ridge will be the only domestic producer of merchant pig iron, which is used to make steel. Currently, American mills import pig iron from countries like Brazil and Sweden. Just like in its past, iron will be the mine’s main motivation, Kennedy said. But the almost-forgotten rare earths could be the icing on the cake.

A little exchange coupling goes a long way.

Rare earths like neodymium, dysprosium, and terbium are important ingredients in the strong magnets that are the key to everything from wind turbines to efficient automobile engines. But China currently produces more than 95 percent of the world’s refined rare earth elements, and global demand is quickly catching up to supply.

While other countries rush to bring more rare earth mines online—a process that can take years—GE researchers working with a Department of Energy Grant have devised a way to use nanocomposite magnet materials to boost magnetism in alloys, getting more magnetism per pound of rare earths. (Coincidentally, next week we're visiting an abandoned iron mine some hope to convert for rare earth mining. Stay tuned for our report).

These new nanocomposite magnets work via exchange coupling, a complex physical property that can be harnessed in nanomaterials to increase magnetism. It’s all in the arrangement of the nanoparticles; exchange coupling doesn’t occur in pure magnetic alloys, but given the right mix and arrangement of nanoparticles of the same metals, researchers can get the same amount of magnetism out of less material—suddenly less is more.

That means not only do magnets require a smaller quantity of rare earths (not to mention iron, cobalt, and other metals), but those magnets are lighter and smaller as well. Ideally we’d innovate around our need for rare earths altogether. In the meantime finding a smart way to get the most out of the neodymium we’ve got ain’t bad.

[Technology Review]

Mountain Pass would be the first domestic producer of rare earths in the U.S. in more than a decade, when cheap Chinese imports rendered the U.S. market unprofitable. The 50-acre pit near Las Vegas is about 500 feet deep currently, but expansion will push it down another 1,000 feet in coming years.

By 2012, Mountain Pass is projected to be capable of delivering around 20,000 tons of rare earth materials per year. Molycorp says it has already lined up contracts for a quarter of the materials it will mine during that first year of full production, and already has letters of intent to sell the rest in U.S., Japanese, and European markets.

The materials that come out of Mountain Pass will be used to make high-strength magnets necessary for electric vehicle engines, wind turbines, and a variety of other high-tech products. However, the U.S. possesses neither the technology nor the licensing to manufacture the neodymium-iron-boron alloy necessary for their production. As such, Molycorp has partnered with Japanese firm Hitachi Metals to manufacture the magnets in the United States.

The development of a domestic U.S. source of rare earths really doesn’t come as a surprise, though it does add another wrinkle to the ongoing rare earhts narrative that is increasingly seeing the U.S., Europe, and Japan aligning themselves opposite China in a sometimes quiet, sometimes overt struggle for these prized raw materials that are necessary to manufacture everything from portable electronics to emerging green technologies to high-tech weaponry. Both the Department of Energy and the Department of Defense have voiced concerns about a disruption in supply, concerns that were exacerbated this year when China quietly imposed a brief and unofficial embargo on exports to Japan.

[Technology Review]

China’s monopoly on the global supply of rare-earth elements has been of particular worry lately as tensions between China and Japan, and then between China and the West, recently led to something of an unofficial embargo on the prized minerals. The faux embargo has since lifted, but it left every industrialized nation not named China feeling economically vulnerable. Nations from Japan to the U.S. to Europe have since scrambled to find independent supply chains.

But it’s the rising prices of more common metals like copper and nickel, rather than rare earths, that are driving some visionaries to look to the seafloor. Scattered at the bottom of the oceans are vast numbers of potato-sized rocks called manganese nodules that contain harvestable amounts of copper, cobalt, nickel, and their namesake manganese.

Previously it wasn’t economically viable to build giant machines to scour the seafloor for nodules, but with commodities like copper and nickel gaining value that economic model might change. Advances in robotics have made the idea of fleets of seafloor mining far more viable (remember those ‘bots that tied off the BP well?), and now that it’s been established that manganese nodules also contain rare earths, that model improves further.

Especially if China were to ever turn off its rare earths spigot. China supplies more than 95 percent of the global supply of processed rare earths, which are necessary to manufacture everything from personal electronics to cutting edge military technology to computers. And China and the West, while economic partners, aren’t always on the friendliest of terms.

In terms of challenges, mining the seafloor wouldn’t be easy. But tapping fleets of robots to do our dirty work on the ocean floor would make for a smart use of technology that would undoubtedly save human lives. The recent Chilean mine disaster, as well as several mining accidents in the U.S. over the last decade, serve as reminders that the deeper we go into the Earth seeking the things that fuel our economies, the more dangerous it becomes.

Compared with the kind of ordeal the 33 Chilean miners just survived, scooping rocks off the seafloor seems relatively easy. Plus we’d learn a lot about undersea robotics along the way. If the market justifies the cost, it certainly won't hurt to have increased dependable supplies of copper and nickel, and if it helps diversify the available global sources of rare earth elements, well, that’s icing on the economic cake.

[NYT]

Experts warn that rare-earth rarity could touch off trade wars

Back in September it was reported that Chinese customs officials had halted shipments of rare earths elements to Japan though no official embargo was declared by the Chinese government. Two weeks ago it was further reported that China had expanded the rare earths suspension to include the U.S. and Europe. China exports more than 95 percent of the world’s supply of rare earth elements, which are necessary materials for the manufacture of a vast variety of modern goods, ranging from hybrid car engines to wind turbines to weapons systems to personal electronics.

Japan’s decision to seek out non-Chinese sources of rare earths comes as the Geological Society of America considers the role of rare earths in an alternative energy future at the group’s annual meeting on Tuesday. In a paper that will be presented tomorrow, geologist point out that rare earth elements and other scarce metals are the backbones of alternative energy tech like photovoltaic cells, wind turbine magnets, high-capacity battery tech, and fuel cells.

Because the U.S. hasn’t tapped its domestic resources of rare earths – and won’t be able to produce an independent supply chain for at least fifteen years according to GAO estimates – any shift to an alternative energy economy would simply trade one foreign dependency for another. That could set the stage for trade wars as China needs more of its neodymium, gallium, zinc, lithium, and various rare earth elements to pursue its ambitious alternative energy plans.

Japan will help the Vietnam explore and survey its northern provinces for future rare earth element exploitation and help the Vietnamese develop environmentally friendly technologies for extraction and processing of the elements, but at best it would be a few years before meaningful production and export would begin. The U.S. will keep seeking out rare earths at home and keep leaning on China to keep the exports coming. And global economies will keep its fingers crossed that China does so.

[China.org, Eurekalert]