Massive REE Deposits FoundOcean floor muddies China's grip on '21st-century gold'
On Sunday July 3, 2011, 6:32 pm EDT
China's monopoly over rare-earthmetals could be challenged by the discovery of massive deposits of thesehi-tech minerals in mud on the Pacific floor, a study on Sundaysuggests.
China accounts for 97 percent of the world's productionof 17 rare-earth elements, which are essential for electric cars,flat-screen TVs, iPods, superconducting magnets, lasers, missiles,night-vision goggles, wind turbines and many other advanced products.
Theseelements carry exotic names such as neodymium, promethium and yttriumbut in spite of their "rare-earth" tag are in fact abundant in theplanet's crust.
The problem, though, is that land deposits of themare thin and scattered around, so sites which are commerciallyexploitable or not subject to tough environment restrictions are few.
As a result, the 17 elements have sometimes been dubbed "21st-century gold" for their rarity and value.
Productionof them is almost entirely centred on China, which also has a third ofthe world's reserves. Another third is held together by former Sovietrepublics, the United States and Australia.
But a new study,published in the journal Nature Geoscience, points to an extraordinaryconcentration of rare-earth elements in thick mud at great depths on thePacific floor.
Japanese geologists studied samples from 78 sitescovering a major portion of the centre-eastern Pacific between 120 and180 degrees longitude.
Drills extracted sedimentary cores to depths that in place were more than 50 metres (165 feet) below the sea bed.
More than 2,000 of these cores were chemically tested for content in rare-earth elements.
Thescientists found rich deposits in samples taken more than 2,000kilometres (1,200 miles) from the Pacific's mid-ocean ridges.
Thematerial had taken hundreds of millions of years to accumulate,depositing at the rate of less than half a centimetre (0.2 of an inch)per thousand years. They were probably snared by action with ahydrothermal mineral called phillipsite.
At one site in thecentral North Pacific, an area of just one square kilometre (0.4 of asquare mile) could meet a fifth of the world's annual consumption ofrare metals and yttrium, says the paper.
Lab tests show thedeposits can be simply removed by rinsing the mud with diluted acids, aprocess that takes only a couple of hours and, say the authors, wouldnot have any environmental impact so long as the acids are not dumped inthe ocean.
A bigger question is whether the technology exists forrecovering the mud at such great depths -- 4,000 to 5,000 metres(13,000 to 16,250 feet) -- and, if so, whether this would becommercially viable.
In an email exchange with AFP, lead authorYasuhiro Kato, a professor of economic geology and geochemistry at theUniversity of Tokyo, said the response from mining companies was as yetunknown, "because nobody knows the presence of the (rare-earth) -richmud that we have discovered."
"I am not an engineer, just ageoscientist," Kato said. "But about 30 years ago, a German miningcompany succeeded in recovering deep-sea mud from the Red Sea. So Ibelieve positively that our deep-sea mud is technologically developableas a mineral resource."
The market for rare-earth elements has tightened considerably over the last couple of years.
Chinahas slashed export quotas, consolidated the industry and announcedplans to build national reserves, citing environmental concerns anddomestic demand.
These moves led to a fall of 9.3 percent inChina's exports of rare-earth metals last year, triggering complaintsabroad of strategic hoarding and price-gouging.
Japanese industrysources also said China temporarily cut off exports last year during aterritorial row between Asia's two largest economies.