Monday, July 4, 2011

Post # 47: The Race for Rare Earths

Back in Post # 27, I discussed the relevance of rare earths to our high-tech society.  Rare earths are used in an astonishing variety of today's high-tech items.  Computer displays, windmill turbines, solar PV arrays, loud speakers, cell phones, and a plethora of other gadgets we rely on daily would not exist, or would not be nearly as functional, without their rare earth ingredients.

Though the U.S. was the major producer of rare earths for many years, China is currently the source for ~ 97% of rare earth production.  (There's an interesting short video piece on this topic here.

All of this could change if the recent news out of Japan plays-out.  It seems the Japanese have been searching the Pacific sea bed floor for rare-earth-rich ocean sediments and have apparently hit the "jackpot".  According to recent media postings here, the sediment in 1 square km of ocean sediment (found at 3,500 to 6,000 meters below the surface of the ocean) in some locations, could provide 20% of the current total annual world production of rare earths.  The total estimated inventory could be as high as 100 billion tons of these valuable natural resources.  If these repositories can be economically recovered, the potential exists to reduce China's monopoly on rare earths and possibly even reduce their cost.

There's just one wee tiny challenge.... how does one mine these deposits in the dark depths of the ocean, without creating unintended and unacceptable consequences?  The dialog is beginning.  See here and here.  The easiest approach appears to involve leaching the minerals out of the ocean sediment with acid.  Does one do that on the sea-bed floor, or can the sediments be mined and transported to the surface for this treatment?  And what else does one bring up with these sediments?  How are the residues and "waste streams" from this process treated and returned to the environment?  What about the damage to the deep ocean eco-system? All of these questions and many more make for an intense debate - complicated by the fact that no one owns the sea bed in international waters where most of these deposits have been found.

So, some interesting news on this Fourth of July.

Wishing all of you... especially those serving us in harm's way and their families here at home, a peaceful and happy Independence Day.


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