Rare Earths



Ytterbium (Yb, atomic number 70) – Marignac discovered a new component in the earth then known as erbia in 1878 which he called ytterbia. In 1907, Urbain separated ytterbia into two components which he called neoytterbia and lutecia. The elements in these earths are now knows as ytterbium and lutetium, respectively. These elements are identical with aldebaranium and cassiopeium (discovered independently and at about the same time by von Welsbach). Ytterbium occurs along with other rare earths in a number of rare minerals. The element was first prepared by Klemm and Bonner in 1937 by reducing ytterbium tri-chloride with potassium. Their metal was mixed, however, with KCI. Daane, Dennison and Spedding prepared a much purer form in 1953 from which the chemical and physical properties of the element could be determined. It is commercially recovered principally from monazite sand which contains about 0.03%. Ion-exchange and solvent extraction techniques developed in recent years have greatly simplified the separation of the rare earths from one another. Ytterbium is a silvery and lustrous metal that is very soft and reacts very rapidly with oxygen. Even though the element is fairly stable, it should be kept in closed containers to protect it from air to moisture. Ytterbium is readily attacked and dissolved by dilute and concentrated mineral acids and reacts slowly with water. Ytterbium is the least abundant amongst the rare earths. Its chemistry is the least understood therefore it is not used often.

Ytterbium has some possible uses, they are as follows:

  • Ytterbium metal may be used in improving the grain refinement, strength and other mechanical properties of stainless steel.
  • Electronic uses due to the properties of the metals change.
  • Measure of pressure within nuclear explosions.
  • Metallurgy