How are rare earths used?

 

Rare earths are the backbone of many of the devices we use on a daily basis, as well as the technologies that are already contributing to the health of our planet. Rare earths affect many areas of our everyday lives.

 


Rapid global industrialisation and population growth has placed increased pressure on the availability of raw materials.

Because of their specific optical, magnetic and catalytic properties, rare earths are used in a variety of applications:

  • Industrial processes: petroleum catalytic cracking, chemical catalysis
  • Glass manufacturing: polishing, UV absorption, refractive index improvement
  • Automotive emission control: catalytic convertors
  • Energy storage: NiMH batteries
  • Energy efficient electrical motors: rare earth permanent magnets enabling lighter and more efficient motors
  • Special steel alloys: lighter and less brittle
  • Electronics: semi-conductors manufacturing, micro-motors for computers and servers hard disks, acoustic devices including earphones and high quality speakers, and micro-capacitors used in many electronic devices
  • Lighting: energy efficient fluorescent lamps
  • Medical: PET scanners, MRI
  • Plus a number of new applications under development​

Auto Catalysts

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Did You Know – rare ​​​​earths in catalytic converters improve their effectiveness

    • ​An automotive catalytic converter (autocat) transforms the primary pollutants in engine exhaust gases into non-toxic compounds.  It is called a 3-way catalyst because it achieves three different chemical reactions:
    1. Oxidizing carbon monoxide into non-harmful carbon dioxide​
    2. Oxidizing complex unburned hydrocarbonates into carbon dioxide and water
    3. Converting oxides of nitrogen (NOx) with carbon monoxide into harmless nitrogen and carbon dioxide
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The 3-way catalyst consists of a mixture of precious metals, zirconium and rare earth (mostly cerium) wash coated into a brick inserted in the vehicle's exhaust pipe.

This market segment has been growing steadily above 5% per annum in the past 10 years and is expected to continue to grow as emission control regulations around the world are strengthened.

Additional catalytic systems are being developed, especially for addressing the higher oxides of nitrogen (NOx) emissions by diesel cars (linked to their higher combustion temperature). One of the most promising technologies (called Lean Nox Trap) uses cerium as a major catalyst and is particularly suitable for compact diesel cars. ​​

Many scientists believe that global warming is caused by a human-driven increase in greenhouse gases and their impact on the earth’s atmosphere. With our society becoming more aware of the part we have to play in addressing global warming, governments of today are now legislating higher environmental and lower emission standards in both domestic and industrial settings. Rare earths are playing a pivotal role in greenhouse gas reduction through their unique application in automotive catalytic converters, hybrid vehicles, wind turbines, and energy efficient compact fluorescent light bulbs

Wind Turbines

Did You Know – rare earth magnets mean wind turbines are now highly efficient

Wind turbines use the impact of wind to turn two or three propeller like blades around a single rotor, which is connected to a main shaft. It is the spinning of this shaft that creates electricity.

Many conventional wind turbines use a gearbox, which connects the blades to the generator and is one way to increase blade rotation speed in order to generate electricity in low to moderate wind speeds. Direct Drive turbines do not use a gearbox. Hence they are cheaper to make, lighter, more reliable and cheaper to maintain. In addition, they provide better yield, especially in light winds.

This technology is expected to become the technology of choice in the coming years, especially for offshore wind turbines (where low maintenance is vital) and because many of the available high wind locations have already been used.

A 3MW direct drive turbine consumes close to 2 tonnes of rare earths permanent magnets. The wind turbine market is expected to account for approximately 30% of the global growth in the use of rare earths magnets from 2015 to 2025.

 

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Increased population and economic growth has placed even greater demand on the world’s energy resources. Rare earths are helping conserve our limited fossil fuel reserves by making us all more energy efficient. From vehicle catalytic converters, hybrid cars, and compact fluorescent light bulbs through to fluid cracking catalysts used by the oil industry, rare earths are a key enabler for the development of energy saving technologies

Energy Efficiency 

Did You Know – rare earths enable energy efficient light bulbs to use 75% less power

Key components of energy efficient lighting are phosphors containing rare earths, which enable fluorescent lamps to use approximately 75% less power to produce the same amount of light as a standard incandescent light bulb. According to the former US President, Bill Clinton, the energy savings that could be achieved if every home swapped their incandescent light bulbs to compact fluorescent light bulbs would reduce greenhouse emissions In the US by up to 50%.

LED-based lighting technology is a growing competitor of the rare earth fluorescent lamps, because it provides a longer life and better energy efficiency. However, as LED optical characteristics (mono direction emissions) require light diffusion systems, rare earth fluorescent lamps remain the technology of choice especially for ambient professional lighting.

Did You Know – rare earths are used to produce gasoline, diesel and gas more efficiently

Catalytic cracking has emerged as the most widely used petroleum refining process in the world today with 10.6 MMBPD processed daily. Two major factors that have increased the need for cracking are the depletion of old, light crudes and the increasing demand for gasoline. A typical barrel of crude is approximately 20% straight run gasoline, but demand is nearly 50% per barrel. This demonstrates the need for an efficient catalytic cracking unit to increase gasoline production, through breaking high molecular weight hydrocarbons into smaller pieces of lower boiling point fractions.

In a modern refinery, 25% of the crude oil goes through the FCC unit.

 

Better yields of high-octane gasoline are obtained in today's FCC units using a high activity zeolite-based catalyst held in a matrix of amorphous silica-alumina. Lanthanum is used to improve the thermal stability of the catalyst (by maintaining a high surface area when operating temperature increases), in a range of 2 to 4wt%. During normal operations, increasing reaction temperature, catalyst/oil ratio, catalys​t activity, and contact time will yield a higher conversion of feedstock.​​

The digital era has continued to develop at a rapid pace over the past decade. Whether at work, home, or play, people want to be able to access today’s digital technologies at the press of a button. Rare earths have been key to these products becoming faster, lighter, and more efficient. 

Digital Technologies

Did You Know – rare earths have helped miniaturise today's digital technologies  

Rare earths have played an important role in helping reduce energy consumption in many of today's high-tech electronic, audio-visual, photographic, and music devices including mobile phones, IPODs, LCD televisions, camera lenses, PCs, and CD/DVD players.

They are also the driving force behind the miniaturisation of these everyday consumer products. Take for example a SMART mobile phone where rare earths are used to polish the glass surface of the phone. Rare earths are also found in the magnets, which enable the phone speakers to provide high-quality sound. Each mobile phone only contains a few grams of rare earths. This may not sound a lot but when you calculate there are as many as six billion or more active mobile phone accounts across the globe, you can see why rare earths are in such strong demand.

Did You Know – rare earths helps reducing the weight of our cars 

Modern cars include a growing number of electrical motors, including for seat adjustment, wipers, side mirrors, roof movements, ABS brake pumps, EPS (Electronic Power Steering) replacing traditional hydraulic systems,  air conditioning compressors, cooling water pumps, and oil pumps – a total that varies between 20 and 50 small electrical motors.

NdFeB permanent DC motors allow substantial weight reductions, thus supporting better energy efficiency for the car.

As an example, (photo below), a ferrite based ABS pump weighs twice as much and is twice as large as an NdFeB equivalent (0.7kg versus 1.4kg).

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Overall, the extensive use of NdFeB DC motors allows several kg of weight reduction per car.

In addition, the better efficiency of NdFeB motors helps improve the range of electrical and plug-in hybrid vehicles.

These advantages are even more important when it comes to electrical, plug-in hybrid and hybrid cars, since they also include a drive-train electrical motor (and an electrical generator for hybrids and plug-in hybrids).​