REE - Rare Earth Elements and their Uses
|This chart shows a history of rare earth element production, in metric tons of rare earth oxide equivalent, between 1950 and 2012. It clearly shows the United States' entry into the market in the mid-1960s when color television exploded the demand. When China began selling rare earths at very low prices in the mid-1980s, mines in the USA cut production and then went inactive in the late 1990s. When China cut exports and rare earth prices skyrocketed in 2010, mines in the USA began producing again. India has steadily produced the equivalent of a few thousand metric tons throughout the time interval shown by this chart and is the most important contributor to the production from "other" countries.|
What Are Rare Earth Elements (REEs)?
Rare earth elements are a group of seventeen chemical elements that occur together in the periodic table (see image at right). The group consists of yttrium and the 15 lanthanide elements (lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, and lutetium). Scandium is found in most rare earth element deposits and is sometimes classified as a rare earth element. The International Union of Pure and Applied Chemistry includes scandium in their rare earth element definition.
The rare earth elements are all metals, and the group is often referred to as the "rare earth metals." These metals have many similar properties and that often causes them to be found together in geologic deposits. They are also referred to as "rare earth oxides" because many of them are typically sold as oxide compounds.
Uses of Rare Earth Elements
Rare earth metals and alloys that contain them are used in many devices that people use every day such as computer memory, DVDs, rechargeable batteries, cell phones, catalytic converters, magnets, fluorescent lighting and much more.
During the past twenty years, there has been an explosion in demand for many items that require rare earth metals. Twenty years ago there were very few cell phones in use, but the number has risen to over 7 billion in use today. The use of rare earth elements in computers has grown almost as fast as cell phones.
Several pounds of rare earth compounds are in batteries that power every electric vehicle and hybrid-electric vehicle. As concerns for energy independence, climate change and other issues drive the sale of electric and hybrid vehicles, the demand for batteries made with rare earth compounds will climb even faster.
Rare earths are used as catalysts, phosphors, and polishing compounds. These are used for air pollution control, illuminated screens on electronic devices, and the polishing of optical-quality glass. All of these products are expected to experience rising demand.
Other substances can be substituted for rare earth elements in their most important uses; however, these substitutes are usually less effective and costly.
From the 1950s until the early 2000s, cerium oxide was a very popular lapidary polish. It was inexpensive and very effective. The recent price increases have almost eliminated the use of cerium oxide in rock tumbling and the lapidary arts. Other types of polish, such as aluminum and titanium oxide, are now used in its place.
Critical Defense Uses
Rare earth elements play an essential role in our national defense. The military uses night-vision goggles, precision-guided weapons, communications equipment, GPS equipment, batteries and other defense electronics. These give the United States military an enormous advantage. Rare earth metals are key ingredients for making the very hard alloys used to make armored vehicles and projectiles that shatter upon impact in thousands of sharp fragments.
Substitutes can be used for rare earth elements in some defense applications; however, those subsitutes are usually not as effective and that diminishes military superiority. Several uses of rare earth elements are summarized in the table below (5).
Are These Elements Really "Rare"?
Rare earth elements are not as "rare" as their name implies. Thulium and lutetium are the two least abundant rare earth elements - but they each have an average crustal abundance that is nearly 200 times greater than the crustal abundance of gold (1). However, these metals are very difficult to mine because it is unusual to find them in concentrations high enough for economical extraction.
The most abundant rare earth elements are cerium, yttrium, lanthanum and neodymium (2). They have average crustal abundances that are similar to commonly used industrial metals such as chromium, nickel, zinc, molybdenum, tin, tungsten and lead (1). Again, they are rarely found in extractable concentrations.
History of Rare Earth Production and Trade
Before 1950 there was relatively little demand for rare earth elements. At that time, most of the world's supply was being produced from placer deposits in India and Brazil. In the 1950s, South Africa became the leading producer from rare earth bearing monazite deposits. At that time, the Mountain Pass Mine in California was producing minor amounts of rare earth oxides from a Precambrian carbonatite.
The demand for rare earth elements saw its first explosion in the mid-1960s, as the first color television sets were entering the market. Europium was the essential material for producing the color images. The Mountain Pass Mine began producing europium from bastnasite, which contained about 0.1% europium. This effort made the Mountain Pass Mine the largest rare earth producer in the world and placed the United States as the leading producer.
China began producing noteable amounts of rare earth oxides in the early 1980s and became the world's leading producer in the early 1990s. Through the 1990s and early 2000s, China steadily strengthened its hold on the world's rare earth oxide market. They were selling rare earths at such low prices that the Mountain Pass Mine and many others throughout the world were unable to compete and stopped operation.
At the same time, world demand was skyrocketing as rare earth metals were designed into a wide variety of defense, aviation, industrial and consumer electronics products. China capitalized on its dominant position by restricting exports and allowing rare earth oxide prices to rise to historic levels.
Around 2010, an awakening of rare earth markets occurred as prices of most rare earths began to rise. Mining companies in the United States, Australia, Canada and other countries began to reevaluate old rare earth prospects and explore for new ones. The Chinese dominance peaked in 2010 when China produced about 95% of the world's rare earth oxides and was the world's leading exporter.
Chinese companies have responded at the same time by seeking rare earth properties in other countries. For example, in 2009 China Non-Ferrous Metal Mining Company bought a majority stake in Lynas Corporation, an Australian company that has one of the highest outputs of rare earth elements outside of China.
Mines in Australia produced significant amounts of rare earth oxides in 2011, making a contribution of a little over 1% to the world's total production. In 2012, the Mountain Pass Mine came back into production and the United States produced about 6% of the world's rare earth elements, with Australia making a little over 3%. China remains the dominant producer with nearly 90% of the world's mine production on a rare earth oxide equivalent basis. Minor production may have occurred in Indonesia, Commonwealth of Independent States, Nigeria, North Korea, and Vietnam (3).
By 2012, exploration and development assessments were underway at many sites in the United States, Australia and Canada. Activity in Brazil, Finland, Greenland, India, Kyrgyzstan, Madagascar, Malawi, Mozambique, South Africa, Sweden, Tanzania, Turkey, and Vietnam was also underway.
The United States Geological Survey estimates that China holds about 50% of the world's reserves of rare earth elements. This provides an opportunity for other countries to become important producers now that China is not selling rare earth materials at prices below production costs in other countries.
Rare Earth Consumption and Supply
Many manufacturing companies, concerned about the high prices of rare earth metals and oxides, began looking for ways to reduce their consumption of these materials. Although substitutes are available for many rare earth materials, they generally do not perform as well.
The greatest success has been in using smaller amounts of rare earth materials in the devices that require them or moving to technologies that do not require the use of rare earth materials. This effort has resulted in a decline in the amounts of rare earth materials used in some types of magnets and a shift from rare earth lighting products to light-emitting diode technology.
In addition to being the world's largest producer of rare earth materials, China is also the dominant consumer. They use rare earths mainly in manufacturing electronics products for domestic and export markets. Japan and the United States are the second and third largest consumers of rare earth materials.
Dangers of a Dominant World Producer
Supply and demand normally determine the market price of a commodity. As supplies shrink, prices go up. As prices go higher, those who control the supply are tempted to sell, and entrepreneurs start developing new sources of supply.
With rare earth elements, the time between an entrepreneur's decision to acquire a property and the start of production can be several years or longer. There is no quick way to open a new mining property.
If a single country controls almost all of the production and makes a firm decision not to export, then the entire supply of a commodity can be quickly cut off. That is a dangerous situation when new sources of supply take so long to develop.
In 2010 China announced that they would significantly restrict their rare earth exports to ensure a supply for domestic manufacturing and for environmental reasons. This announcement triggered panic buying and some rare earth prices shot up exponentially. In addition, Japan, the United States, and the European Union complained to the World Trade Organization about China's restrictive rare earth trade policies.
World Rare Earth Mineral Resources
"Rare earths are relatively abundant in the Earth's crust, but discovered minable concentrations are less common than for most other ores. U.S. and world resources are contained primarily in bastnäsite and monazite. Bastnäsite deposits in China and the United States constitute the largest percentage of the world's rare-earth economic resources, while monazite deposits in Australia, Brazil, China, India, Malaysia, South Africa, Sri Lanka, Thailand, and the United States constitute the second largest segment.
Apatite, cheralite, eudialyte, loparite, phosphorites, rare-earth-bearing (ion adsorption) clays, secondary monazite, spent uranium solutions, and xenotime make up most of the remaining resources. Undiscovered resources are thought to be very large relative to expected demand." Quoted from the United States Geological Survey's Mineral Commodity Summary (2).
Rare Earth Element Outlook
The global demand for automobiles, consumer electronics, energy-efficient lighting, and catalysts is expected to rise rapidly in the future. Rare earth elements are heavily used in all of these industries and their use is expected to rise.
Rare earth magnet demand is expected to increase, as is the demand for rechargeable batteries. New developments in medical technology are expected to increase the use of surgical lasers, magnetic resonance imaging, and positron emission tomography scintillation detectors.
One problem and opportunity with rare earth element production is that monazite, an ore of rare earth metals, is naturally radioactive. This can cause environmental problems during mining. However, monazite often contains recoverable amounts of thorium, which can sometimes be removed to reduce the environmental concerns.
Contributor: Hobart King
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