Rare Earth 101
- Published on Saturday, 28 November 2009 15:15
RARE EARTH BASICS
Rare Earth Elements (‘REE’) are non-toxic elements essential to a cleaner environment and reduced reliance on fossil fuels. Also, REE are an enormous potential benefits to human health.
There are 16 REE in total, as defined by the U.S. Geological Survey, 15 lanthanide elements appearing at the bottom on the Periodic Table, with atomic numbers ranging from lanthanum (57) to lutetium (71), plus the metal yttrium (39); all of which display similar physical and chemical properties. REE deposits tend to occur in two sub-groups:
- Light rare earth elements (‘LREE’), which include lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), and samarium (Sm)
- Heavy rare earth elements (‘HREE’), which are less common and more value, include europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb) and lutetium (Lu)
Yttrium (Y) most commonly occur in association with HREE sub-group
REE are not particularly rare; similar abundance in the earth’s crust to nickel or tin, but generally not concentrated in commercial ore deposits.
COMMON PROPERTIES OF RARE EARTHS
- Silvery-white metals that tarnish when exposed to air, thereby forming their oxides
- Burns easily in air; at elevated temperatures many rare earths ignite and burn vigorously
- Relatively soft metals; hardness
- increases with higher atomic numbers
- Many REE compounds fluoresce strongly under ultraviolet light
- Reacts with water to liberate hydrogen gas, slowly in cold/quickly upon heating
- Reacts with dilute acid to release hydrogen gas rapidly at room temperature
- Most REE compounds are strongly paramagnetic
Prices for REE's differ a lot. To give you an idea, look at the next overview which was on the Quest Uranium site:
Current prices can be found here.
The next chart shows clearly how the price for REE's went up the last few years.