Reserves of rare earths

The world reserves of rare earths are summarized in Table 1.4. The reserve base encompasses current economic reserves, marginally economic reserves and sub-economic reserves. The locations of the major rare earth deposits in the world are depicted in Fig. 1.1. 

Note the striking fact that 80% of the world reserves of rare earths are located in China with 11% in North America and 5% in India. Both the Chinese (at Bayan Obo,... 

The chart below shows the estimated world s reserves of rare earth metals. Although large resources are available, world mine production has been almost entirely in China. However, for a number of reasons, mining of reserves in the US, Australia and other countries is now (2011) becoming economically viable, and competitive markets for the rare earth metals are expected to replace the China-dominated market. 

Commercial mining of rare-earth reserves began ia the late 1800s. Mona2ite was the principal rare-earth source up until 1965. Thereafter bastnaesite production exceeded mona2ite production and as of 1992 bastnaesite, which is the world s principal source of rare earths, constituted 65% of world output of rare-earth minerals (see Table 5). In addition to the conventional ores, there are several other rare-earth resources having a low level of iadustrial production. 

Co. of California. Proven orebody reserves at the end of December 1978 were 365,000 metric tons, with indicated reserves of over 3 million metric tons of rare earth oxide (REO). Current mine production capacity is 27,000 metric tons per year of bastnaesite concentrate produced in 3 grades a 60% REO unleached concentrate, a 70% REO leached concentrate (SrO and CaO removed), and a 90% REO calcined concentrate (CO2 removed). In 1977, shipments totaled 13,521 metric tons of contained REO. Polishing compounds consumed approximately 10% of this production. 

RARE-EARTH ELEMENTS AND METALS. Sometimes referred to as the fraternal fifteen," because of similarities in physical and chemical properties, the rare-earth elements actually are not so rare. This is attested by Fig. 1, which shows a dry lake bed in California that alone contains well in excess of one million pounds of two of die elements, neodymium and praseodymium. The world s largest rare earth body and mine near Baotou, Inner Mongolia, China is shown in Fig. 2. It contains 25 million tons of rare earth oxides (about one quarter of the world s human reserves. The term rare arises from the fact that these elements were discovered in scarce materials. The term earth stems from die tact that the elements were first isolated from their ores in the chemical form of oxides and that the old chemical terminology for oxide is earth. The rare-earth elements, also termed Lanthanides, are similar in that they share a valence of 3 and are treated as a separate side branch of the periodic table, much like die Actinides. See also Actinide Contraction Chemical Elements Lanthanide Series and Periodic Table of the Elements. 

Handbook on the Physics and Chemistry of Rare Earths, Vol. 38 2008 Elsevier B.V. ISSN 0168-1273, D01 10.1016/S0168-I273(07)38002-1 All rights reserved... 

The lanthanides (Ln) include lanthanum (La) and the following fourteen elements—Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu— in which the 4f orbitals are progressively filled. These fifteen elements together with scandium (Sc) and yttrium (Y) are termed the rare-earth metals. The designation of rare earths arises from the fact that these elements were first found in rare minerals and were isolated as oxides (called earths in the early literature). In fact, their occurrence in nature is quite abundant, especially in China, as reserves have been estimated to exceed 84 x 106 tons. In a broader sense, even the actinides (the 5f elements) are sometimes included in the rare-earth family. 

The present title consists of twelve chapters. The first chapter is an introduction covering definition, classification, properties, world reserves, methods of processing from ores, methods of separation both classical and modem, and analytical chemistry of rare earths, including classical and modem methods. 

In recent years, the characteristics of the rare earth market place have become a concern. The United States currently has 13 percent of the world s rare earth reserves and was the largest supplier of rare earth metals from about 1965 until 1985, when China, which owns 48 percent of the world reserves, entered the world market. China now supplies 97 percent of the rare earth needs worldwide. In 2010, China shook up global rare earth markets when it cut off rare earth shipments to Japan for a month because of a diplomatic dispute. The power of one nation to essentially control rare earth availabihty to all other nations is seen by many as a serious issue. 

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. 

World reserves are believed to be sufficient to meet forecast world demand well into the 21 century. Several world class rare earth deposits in Australia and China have yet to be developed because world demand is currently met by existing production. The long-term outlook is for an increasing competitive and diverse group of rare earth suppliers. As research and technology continue to advance the knowledge of rare earth minerals and their interactions with other elements, the economic base of the rare earth industry is expected to continue to grow. New applications are expected to be discovered and developed. 

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