Rare earth metals, also called rare earth elements, are a general name of 17 elements, namely the scandium, yttrium and lanthanide series in Subgroup IIIB of the periodical table of elements, which are usually denoted by R or RE.     

      Rare earth metals have been widely used in electronic, petroleum and chemical, metallurgical, machinery, energy resources and light industries, environmental protection and agriculture. They can be used to produce fluorescent materials, materials for rare-earth metal hydride cells, and light sources, magnetic, catalytic, precise ceramic, laser, superconductive, magnetostriction and magneto-refrigerating materials, magneto-optic memories and optical fibers.

      China is endowed with abundant resources of rare earth minerals and there are very favorable conditions for the development of such resources. The explored reserves rank first in the world, which has laid a sound basis for the development of industries related to rare earth metals.

      Dispersed metals generally refer to the following 7 elements: gallium (Ga), indium (In), thallium (Tl), germanium (Ge), selenium (Se), tellurium (Te) and rhenium (Re), but some scientists incorporate rubidium, hafnium, scandium, vanadium and cadmium into this group.

      As important new materials in high-tech fields, rare earth elements (REE) and dispersed elements have found very extensive applications. Special dispersed elements are indispensable to develop new materials such as semiconductors composed of dispersed and nonferrous metals, electro-optical materials, special alloys and organic metallic compounds. Therefore, such metals have a wide scope of application in telecommunication, electronic computers, space industry, medicine and hygiene, and sensitive, photoelectric, energy source and catalytic materials. China is rich in dispersed metals, thus providing abundant resources for the industries of dispersed metals.

      In the world, the mining industry of rare earth metals is progressing with the development of industries related with REE. Some developed countries began extensive prospecting and exploitation of rare earth minerals in the 1950s. The USA, China, Australia and India are the major countries in terms of the production of REE. The world's production capacity of REE is estimated at 70,000 tons (REE oxides). The Molycorp Inc. in the USA, Rhone Poulenc Co. in France and some State-owned enterprises in China make up 60% of the world's output of rare earth metals.

      In China, the industry of rare earth metals was initiated in 1949 and in the late 1950s almost all rare earth metals could be produced except promethium (Pm). Industrialized production started in the early 1960s and promethium was produced in 1972. A fairly complete industrial system of rare earth metals has been established at present based on abundant resources. Currently, there are a great number of mines, dressing plants and over 10 smelters in China and they produce thousands of varieties of REE products. The reserves of rare earth minerals and the output of bastnaesite both rank first in the world.