Rare Earths – History
The term “rare earths” includes seventeen different chemical elements, some of which are rare and some abundant. These elements have many different uses and applications. Their present relevance and importance are related to their uses in technologies that reduce carbon emissions and combat global warming and climate change.
Rare earths are necessary for the construction of wind turbines and for the production of hybrid and electric vehicles, air conditioning and LED lights. They are also required for the production of electronic items such as portable computers and smart phones. The demand for rare earths in these applications has been growing rapidly for many years
and is expected to continue growing rapidly for many years to come.
The total market for rare earths in 1960 was about 5,000 tons. By 2015, this market had grown to 145,000 tons and there are forecasts that the market will grow to over 200,000 tons by 2020. The Ford Motor Corporation published a report in 2015 entitled “Rare Earths in Vehicles: Current Problems and Future Directions”, which states that “A shortage in supply for neodymium, praseodymium and dysprosium is possible by the end of this decade”.
Neodymium, praseodymium and dysprosium make up 13.4% of the mass of the rare earths in the mine and 85% of the economic value. Neodymium, praseodymium and dysprosium are the rare earth elements used in the manufacture of permanent magnets.
Neodymium and praseodymium form the basis of neodymium-iron-boron (NdFeB) magnets and the addition of dysprosium enables these magnets to operate at high temperatures.
More than half the economic value of the mine ore is in neodymium, followed by around 20% in praseodymium and 10% in dysprosium. The rare earths used in magnetic applications account for about 85% of the value in the ore.
The market for NdFeB magnets has been growing at between 5% and 10% per year for many years. These magnets are used in many products, ranging from miniature speakers in smart phones to wind turbines.
Because of their superior magnetic flux density, neodymium-iron-boron magnets are in high demand for motors and generators. Small (servo) motors power disc drives in computers, electric windows in automobiles and many other electric and electronic appliances. Large motors, such as those in electric cars, use up to 200g of neodymium and 30g of dysprosium per motor. Wind turbine generators contain up to one ton of neodymium per megawatt of electricity generation capacity.
The countries that use the largest quantities of rare earths are China, Japan and the United States. Over the past decade, many international companies have relocated their factories to China to secure rare earth raw materials for their operations.