Separation of the RE Elements

The occurrence of an ore of this type was first observed in Longman (Jiangxi) in 1969. Later it was found in the whole Jiangxi province as well as in Guandong, Guangxi, Hunan and Fuijian. Deposits of this type are now the major source of heavy and medium-heavy rare earths in China. 

From an economic point of view the most important rare earth sources in the world 

The total world reserves are estimated at 100 milHon tormes, counted as the content of rare earth oxide REO. Of this quantity China has 43, the former Soviet Union 19, the United States 13 and Australia 5 million tonnes. This large reserve is satisfactory compared to the actual consumption, although this may increase to an extent that is difficult to anticipate. On the other hand, undiscovered resources are thought to be very large. In addition, a high proportion of the rare earth metals used in modem society may appear as a workable scrap. It is estimated that as much as 30% of the large quantity of RE metals in magnets wiU be recovered and reused. 

Total mine production in the year 2000 was 83.5 thousand tonnes REO, of which China accounted for 73, the United States 5 and India 2.7 thousand tonnes [17.14]. 

The separation of RE metals is one of the most difficult problems within inorganic chemistry. The chemical properties of the elements are so exceptionally similar. When the separation work started with fractional crystallization and precipitation chemists used the small differences in solubility between the RE salts. To some extent the differing basicities of the oxides were also used. As soon as advanced separation techniques, ion exchange and Hquid-Hquid extraction, were developed the situation changed drastically. 

---