Rare earth elements are a set of 17 metals that are integral to our modern lifestyle and efforts to produce advance & ever-greener technologies that give them the ability to discharge and accept electrons, making them an integral component of many modern-day electronic, optical, magnetic, and catalytic uses..
The “rare” designation is a bit of a misnomer: It’s not that they’re not plentiful, but rather that they’re found in small concentrations on the earth, and are very difficult to successfully extract since they blend in with and resemble other minerals in the earth. So though they’re not precisely “rare,” they are scarce.
Which are the Rare Earth Elements?
The rare earth metals can be mostly found in the second row from the bottom in the Table of Elements. According to the Rare Earth Technology Alliance, due to the “unique magnetic, luminescent, and electrochemical properties, these elements help make many technologies perform with reduced weight, reduced emissions, and energy consumption; or give them greater efficiency, performance, miniaturization, speed, durability, and thermal stability.”
In order of atomic number, the rare earth elements are:
- Scandium or Sc (21) — This is used in TVs and energy-saving lamps.
- Yttrium or Y (39) — Yttrium is important in the medical world, used in cancer drugs, rheumatoid arthritis medications, and surgical supplies. It’s also used in superconductors and lasers.
- Lanthanum or La (57) — Lanthanum finds use in camera/telescope lenses, special optical glasses, and infrared absorbing glass.
- Cerium or Ce (58) — Cerium is found in catalytic converters, and is used for precision glass polishing. It’s also found in alloys, magnets, electrodes, and carbon-arc lighting.
- Praseodymium or Pr (59) — This is used in magnets and high-strength metals.
- Neodymium or Nd (60) — Many of the magnets around you have neodymium in them: speakers and headphones, microphones, computer storage, and magnets in your car. It’s also found in high-powered industrial and military lasers. The mineral is especially important for green tech. Each Prius motor, for example, requires 2.2 lbs of neodymium, and its battery another 22-33 lbs. Wind turbine batteries require 450 lbs of neodymium per watt.
- Promethium or Pm (61) — This is used in pacemakers, watches, and research.
- Samarium or Sm (62) — This mineral is used in magnets in addition to intravenous cancer radiation treatments and nuclear reactor control rods.
- Europium or Eu (63) — Europium is used in color displays and compact fluorescent light bulbs.
- Gadolinium or Gd (64) — It’s important for nuclear reactor shielding, cancer radiation treatments, as well as x-ray and bone-density diagnostic equipment.
- Terbium or Tb (65) — Terbium has similar uses to Europium, though it’s also soft and thus possesses unique shaping capabilities.
- Dysprosium or Dy (66) — This is added to other rare-earth magnets to help them work at high temperatures. It’s used for computer storage, in nuclear reactors, and in energy-efficient vehicles.
- Holmium or Ho (67) — Holmium is used in nuclear control rods, microwaves, and magnetic flux concentrators.
- Erbium or Er (68) — This is used in fiber-optic communication networks and lasers.
- Thulium or Tm (69) — Thulium is another laser rare earth.
- Ytterbium or Yb (70) — This mineral is used in cancer treatments, in stainless steel, and in seismic detection devices.
- Lutetium or Lu (71) — Lutetium can target certain cancers and is used in petroleum refining and positron emission tomography.
Mining of Rare Earth Elements
Rare earths metals are difficult to mine because they aren’t found in large quantities or veins like other minerals such as gold. They need to be separated from one another using a variety of mining and processing techniques.
There are three main methods for separating and refining the elements including:
1. Fractional Crystallization,
3. Liquid-Liquid Extraction, or Solvent Extraction.
Most rare earth elements mines only produce these types of elements using large-scale techniques that involve drilling, blasting, and hauling. The elements are separated and purified and then refined to meet industry standards for the proper applications.