10th May 2016

Light Rare Earths

Rare Earths

What Are REE’s And Where Do I Use Them?

  • The term rare earth elements (REEs) describes 17 different elements which have a unique set of properties that makes them very difficult to substitute. They lie at the bottom of the periodic table of elements.
  • The definition of a LREE and HREE is based on the electron configuration of each rare-earth element. LREE have in common increasing unpaired electrons while HREE have paired electrons (a clockwise and counter-clockwise spinning electron). LREE include the atomic number 57 through 64 (La, Ce, Pr, Nd, Pm, Sm, Eu, Gd). HREE include the atomic number 65 through 71 plus number 39 (Tb, Dy, Ho, Er, Tm, Yb, Lu, Y). Scandium (Sc number 21) forms a group in itself as its properties cannot be classified as either a LREE or HREE.
  • These differences in electronic configuration are critical to the individual properties the REE exhibit and how they interact with other elements and compounds.
  • REEs permit an extraordinary wide range of enabling technologies and as such are widely distributed through most consumer and industrial products in the automotive, aerospace, consumer electronics and electrical engineering fields.
  • The most important sector by value is that of REE-bearing permanent magnets, which are used extensively in applications such as motors, couplings and sensors. REE magnets are critical to the efficient operation of large wind turbines and hybrid cars.
  • They are also widely consumed in lighting products, as catalysts and in the production of glass.

Where are REE’s Produced?

  • While each REE is slightly different, on average more than 90% of REE’s are currently produced in China.
  • Chinese practices for production of rare earths are poorly regulated, such that production of REE’s has a significant impact on the environment compared to their relatively small market value.
  • Some critical REE’s like dysprosium (Dy) are only mined in China, which places the supply chain for high power magnets at risk.


shutterstock_wind turbine

Reviewed by




Tasman Metals Ltd