Consumer products that rely on integral use of REE include: catalytic converters, cell phones, digital cameras, and computers. Additionally, Nd, Sm, Gd, Dy, or Pr are used in high power permanent magnets where weight and space are of concern in applications ranging from computer hard drive motors to wind generators. A typical 2-megawatt wind turbine requires 60 kg (132 lbs.) of dysprosium and 372 kg (820 lbs.) of neodymium. In 2011 prices would cost more than $300,000 just for the REE. A typical hybrid car, such as a Toyota Prius, contains about 11.3 kg (25 lbs.) of REE, mostly lanthanum in its rechargeable battery and about 2 kg (4.5 lbs.) of neodymium and dysprosium in its drive motor.
High power permanent magnet supports
geologist’s hammer and grizzly pan.
WSGS photo by Suzanne Luhr.
Fiber-optic cables that transmit signals over long distances require regularly spaced sections of erbium-doped fiber that function as laser amplifiers. Erbium alone possesses the required optical properties for this application. Europium is used as a phosphor activator. In a color television tube it provides the red color seen by the viewer. The light REE lanthanum and neodymium are used as catalysts in the refining of heavy crude oil into usable forms. Gadolinium, which has the highest neutron capture cross section of all the elements, is the material of choice for absorbing high-energy neutrons.
Misch metal is pyrophoric; when scratched it gives off sparks capable of igniting flammable gases. It is used in cigarette lighters and automatic gas-lighting devices. It is also used in making some types of steel as well as in aluminum and magnesium alloys.
The United States uses REE in a wide range of applications, including some that are critical to national security. This makes China’s control of REE a subject of concern. Department of Defense uses REE in lasers, precision-guided munitions, communications and radar systems, avionics, night-vision equipment, satellites, range finders, and control systems. Some uses of REE, listed by element, are shown in the table below.