The Future of Economic Geology - Metals and Society: An Introduction to Economic Geology - page 145

Fig. 6.2 Comparison of the contents of light and heavy REE in two types of ore (From Haxel et al.
(2005), http://pubs.usgs.gov/fs/2002/fs087-02/ )
significant deposits such as Xunwu and Longnan in Jiangxi province in southeast
China. The latter consist of concentrations of ion-adsorption clays that develop in
lateritic weathering crusts on granitic and syenitic rocks in the tropical southern part
of the country. These oxide ores are economically important because they contain
relatively high proportions of the heavy REE (Fig. 6.2 ). In principle they are easy to
mine, being composed of soft materials exposed at the surface; in practice their
exploitation, often in an artisanal manner, has generated major pollution and serious
environmental problems.
China currently produces most of the world's REE and exerts a major control in
global trade in this commodity. During the past decade it has produced REE in large
quantities and at low cost, which encouraged the use of these elements for the
multitude of applications listed above. More recently, with the explosion of interest
in the development of hybrid and electric cars, demand has increased and at the time
of writing China had started to exploit its near-monopoly position. It has restricted
the supply of the elements in part to incite foreign companies to set up factories
within China.
The current crisis in the rare earth elements is due to China's dual control of
Bayan Obo and to the ionic clay deposits. The Bayan Obo deposit was opened as an
iron mine, and the rare earths were initially produced as a by-product. By benefiting
from this situation and using mining practices that would be environmentally
unacceptable in other countries, China was able in the early 2000's to undercut
the global price and this temporarily drove the major producer - Molycorp's
Mountain Pass Mine in the USA - out of business. In 2009 China accounted for
97% of global production, and, by restricting exports, developed a policy to
encourage industries requiring the rare earths to relocate their factories to China.
Bayan Obo, like many other deposits, produces mainly the light REE (low atomic