Friday, 1 February 2013

The increasing importance of rare earth metals


Rare earth metals (REM) are increasingly becoming a critical strategic resource. REMs comprise the fifteen elements of the lanthanide series as well as yttrium, and may be found in over 250 different minerals. They are required for many different applications such as high-strength permanent magnets, catalysts for petroleum refining, metal and glass additives and phosphors used in electronic displays.

China currently holds claim to over 90 percent of the world’s production. As global demand increases, Beijing’s export reductions in recent years have forced high-tech firms to relocate to China and forced other governments to pour money into their exploration and production. An emergent India is among those concerned about China’s control of rare earths. REMs are becoming a strategic resource over which the two emerging giants are competing in Asia.

The only REM bearing minerals that have been extracted on a commercial scale are bastnäsite, monazite, and xenotime. These minerals may be beneficiated using gravity, magnetic, electrostatic and flotation separation techniques. Increased demand for the different products manufactured from REM has resulted in a constriction of supply from China via export quotas. Many new rare earth deposits are currently being developed to help meet the demand void but most of these developing deposits include rare earth minerals for which there is limited processing knowledge.

So it is timely that an excellent review of the beneficiation of REMs has been published in Volume 41 of Minerals Engineering. The paper examines the separation techniques that are currently employed for rare earth mineral beneficiation and identifies areas in need of further research. The authors, from McGill University, Canada observe that there is still limited research into REM beneficiation and there is a significant gap in knowledge. In collaboration with workers from the University of Birmingham, UK, the authors will be presenting work at Physical Separation ’13 in June, showing how a series of magnetic separators (wet variable intensity, wet drum permanent magnet, Frantz Isodynamic Separator) in conjunction with gravity pre-concentration steps (Knelson and Falcon centrifugal concentrators) can beneficiate a rare earth ore.

2 comments:

  1. Brazil presents significant amounts of xenotime. At PUC-Rio, our Group worked on the separation of zircon and xenotime.

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  2. Congratulations to the authors. This is the most downloaded article from Minerals Engineering over the last 90 days

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