Bastnasite neodymium

Gr. neos, new, and didymos, twin) In 1841, Mosander, extracted from cerite a new rose-colored oxide, which he believed contained a new element. He named the element didymium, as it was an inseparable twin brother of lanthanum. In 1885 von Welsbach separated didymium into two new elemental components, neodymia and praseodymia, by repeated fractionation of ammonium didymium nitrate. While the free metal is in misch metal, long known and used as a pyrophoric alloy for light flints, the element was not isolated in relatively pure form until 1925. Neodymium is present in misch metal to the extent of about 18%. It is present in the minerals monazite and bastnasite, which are principal sources of rare-earth metals. 

Although neodymium is the 28th most abundant element on Earth, it is third in abundance of all the rare-earths. It is found in monazite, bastnasite, and allanite ores, where it is removed by heating with sulfuric acid (H SO ). Its main ore is monazite sand, which is a mixture of Ce, La, Th, Nd, Y, and small amounts of other rare-earths. Some monazite sands are composed of over 50% rare-earths by weight. Like most rare-earths, neodymium can be separated from other rare-earths by the ion-exchange process. 

Neodymium is recovered mostly from mineral monazite and bastnasite, the... 

Neodymium oxide is produced from the two principal rare earth minerals, monazite, and bastnasite. The oxide is obtained as an intermediate in the recovery of neodymium metal (See Neodymium). 

Cerium is the most abundant member of the lanthanide, or rare earth, elements. It has two stable valence states, Ce (cerous) and Ce " (ceric). It is found as a trace element in several minerals, but only two, bastnasite, LnFCOs, and monazite, (Ln, Th)P04 (where Ln = a lanthanide element, such as lanthanum, praseodymium, neodymium, or cerium), which are approximately 30 percent and 22 to 25 percent cerium, respectively, are the principal sources of this element. 

The world s resources of rare earth metals lie mainly in deposits of bastnasite in China. The chart below shows that mine production of the ore from China dominates the world s output. Bastnasite is a mixed metal carbonate fluoride, (M,M. ..)C03F. The composition varies with the source of the mineral, but the dominant component is cerium ( 50%), followed by lanthanum (20-30%), neodymium (12-20%) and praseod5mium (w5%). Each of the other rare earth metals (except for promethium which does not occur naturally) typically occurs to an extent of < 1 %. Monazite,... 

Bastnasite (CeFCOs) - a fluorocarbonate of cerium containing 60-70% rare earth oxides (REO), including lanthanum and neodymium - is the world s major source of rare earths. Host rocks include carbonatite, dolomite breccia with syenite intrusives, pegmatite, and amphibole skam. Since 1985, the bastnasite production in China has increased very fast and has dominated the market from the 1990s to the present. 

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