Most people are now familiar with hybrid vehicles, rechargeable batteries, wind turbines (renewable energy) mobile (cell) phones, flat screen display panels, compact fluorescent light bulbs, laptop computers, disk drives and catalytic converters, but it is not widely known that these products, amongst many others, are dependent on the unique properties of Rare Earth Elements.
Rare Earth Elements make the world’s strongest permanent magnets. These magnets are utilized in electric motors to produce greater power and torque, and owing to the power of the magnets, less material is required such that engines can be considerably smaller and lighter in weight. Electric motors that utilize REEs are a key component of hybrid vehicles, which will become increasingly abundant on roads throughout the world in years to come. The powerful REE magnets also permit the miniaturisation of hard disk drives used in many electrical devices. Neodymium and praseodymium are the REEs used in high-powered magnets, but dysprosium and terbium are also used in small amounts to allow magnets to retain their properties to higher temperatures. Magnets are the main application driving REE demand, by value.
Most energy efficient lighting (compact fluorescent lamps) and display panels (LEDS, Plasma, LCDs) require the use of REEs as phosphors. Europium, terbium, and yttrium are the main REEs used in these applications. All applications are considered as strong growth sectors, leading to increasing demand for europium, terbium and yttrium. The use of REEs as phosphors is the second main demand driver for REEs by value.
Many electronic products are powered by rechargeable batteries. One of the most effective rechargeable batteries is the nickel-metal hydride, or NiMH battery that is used in hybrid cars and many other electronic products. A mixed rare earth metal alloy is used as the anode in the NiMH battery, and makes up about 26% of the battery’s weight. Lanthanum is the main REE used in the NiMH battery.
A catalytic converter is a device fitted to the exhaust system of a combustion engine that reduces the toxicity of emissions. Such devices have been fitted to many automobiles in North America since the 1970s. Recent technological advances have seen the emergence of the three-way catalytic converter. This device reduces toxic nitrogen oxides to harmless nitrogen and oxygen, oxidizes toxic carbon monoxide to carbon dioxide, and additionally oxidizes unburnt hydrocarbons. Cerium is the REE used in catalytic converters, where it forms part of the catalyst. Tighter vehicle emission laws are being introduced throughout the world, and by 2010 it is predicted that 95% of all cars manufactured will have catalytic converters.
Rare Earth Elements are also used in another form of catalyst, commonly referred to as a fluid-cracking catalyst. These are being used increasingly in the oil industry as they enhance the efficiency of separating various fractions from oil during the refining process. Lanthanum is the main REE used in fluid cracking catalysts.
The use of REEs in magnets, rechargeable batteries and catalysts accounts for > 60% of REE consumption with demand expected to increase significantly in all these areas.