Rare Metals and Metalloids (RMs) are physically and chemically dissimilar to rare earth elements. However the RMs are diverse and share few overarching similarities. The critical rare metals (RMs) and metalloids discussed in this section are niobium, tantalum, cobalt, indium, zirconium, gallium, and lithium. Most of these elements are mined in substantial quantities that meet world demand. However, the few countries that possess economically viable sources of critical elements are also experiencing booms in technological industry, exploitation of workers, and political instability. This endangers the world supply of RMs over the next 100 years unless changes are made to mining and the consumption of these elements. This overview will serve to outline basic background information behind this element group.
Properties and Applications
The critical rare metals and metalloids all exhibit a diverse range of chemical and physical properties. These properties allow the rare metals to be used in a wide range of energy and technology applications
Tantalum and Niobium are the most chemically linked pair of RMs. They are typically found together in the ore columbite-tantalite ("coltan"). Tantalum is primarily used in capacitors for microelectronics due to its high heat and electrical conductivity. Niobium can be used as an alternative to tantalum capacitors ("Niobium (Columbium) and Tantalum," 2009), but it is used primarily in alloys for superconducting magnets, rockets, turbines, and medical instruments.
Cobalt is important in strong metal alloys, batteries and electroplating, samarium-cobalt magnets (the less powerful predecessors of neodymium-based magnets), and for blue pigments. ("Cobalt Processing," 2012)
Indium and gallium are the metalloids of this group. Since they occupy periodic group XIII, the two elements are chemically similar to each other. Indium is used in the LCD displays for TV screens, computer, and smartphone screens. Gallium is most often used in semiconductors, in the form of gallium arsenide (GaAs). Gallium arsenide’s ability to produce light radiation from electricity is valuable for production of integrated circuits, LEDs, laser diodes, and solar cells (Carpenter, Rob, 1996).
Zirconium is used to create heat and radiation resistant alloys, which are often used in nuclear power plants. Zirconium alloys can also serve functional roles in phones and computers (or mobile and computer technologies)("Rising Prices and Demand for Zirconium," 2011).
Lithium has a broad array of uses. Since it is the lightest solid element on the periodic table, lithium is used to create highly durable and light-weight alloys. Lithium is used globally in lithium ion batteries used in consumer electronics, military and aerospace equipment, and in electric vehicles (Gruber, Paul W., 2011). It is also used in heat-resistant glassware and ceramics, lubricants, air conditioning, and nuclear reactor coolant. Lithium carbonate (Li2CO3) has even been used to treat manic-depressive (bipolar) disorder (Gruber, Paul W., 2011). One challenge that lithium poses is that 40% of economically viable lithium reserves are located in Bolivia under the control of Evo Morales. However, some like geologist Keith Evans suggest that lithium deposits outside of Bolivia are larger than estimated by the U.S. Geological Survey (Romero, S., 2009).
Geology and Mining
High-grade ores naturally occur in specific regions within a few countries. This is a problem since the highly localized nature of these sources implies that the country with the highest grade source, and subsequently the best access to it, will have the ability to sell at lower prices.
Tantalum and niobium are typically found in ores together, primarily in coltan. 80% of coltan is mined in the Congo and sold to the highest bidder by militias of surrounding countries in, according to the UN, "highly organized and systematic exploitation" ("Coltan, Gorillas, and Cellphones," 2001), (Chadwick, Alex, 2001). Cobalt is typically found in copper or nickel ores. 40% of cobalt comes from the Democratic Republic of the Congo, where it is primarily mined by artisanal miners who sell the ore to foreign companies, mainly in China (Benham, A. J., 2005).
There are no sites specially dedicated to mining indium. It is found in very low quantities in zinc ore. China produces over 60% of world’s indium ("Indium Price Supported by LCD Demand and New Uses for the Metal," 2005).
Like Indium, Gallium is often produced as a byproduct of Zinc and Aluminum mining. According the the USGS, "data on world production of primary gallium are unavailable because data on the output of the few producers are considered to be proprietary." Recycled gallium from GaAs scrap is judged in some estimates to make up as much as half of the world supply ("Gallium: The Slippery Metal," 2009).
80% of world zirconium comes from igneous rock and gravel mined in South Africa and Australia. Zirconium is more abundant in the earth’s crust than copper and lead, although most of its sources are not economically viable to mine. However, as demand continues to increase and prices continue to rise, their viability may increase. (U.S. Geological Survey, 2012), ("Supply Shortages of Zircon to Continue, Further Price Rises Unsustainable," 2011).
Lithium is extracted from pegmatites, brines, and sedimentary rocks. The highest concentration brines occur in the relatively shallow ocean waters on the coasts of Chile, Argentina, China, and Tibet (Gruber, Paul W., 2011). Trace amounts of lithium are found in almost all igneous rocks and in the waters of mineral springs, but it is difficult to find economically viable deposits.
("Niobium (Columbium) and Tantalum," 2009) USGS 2009 Minerals Yearbook
("Cobalt Processing," 2012) [http://www.britannica.com/EBchecked/topic/123274/cobalt-processing]
(Carpenter, Rob, 1996) [http://www2.ensc.sfu.ca/~jones/ENSC100/Gamma/gallium.html]
(Chadwick, Alex, 2001) http://www.npr.org/programs/re/archivesdate/2001/dec/20011220.coltan.html
("Coltan, Gorillas, and Cellphones," 2001) (http://www.cellular-news.com/coltan/),
(Benham, A. J., 2005) [http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&ved=0CDMQFjAA&
T3LfGp0AHg4YFQ&usg=AFQjCNEVCX7JNbqamBUXcprjEg79hTBGfQ&sig2=sRiQSP9uuxrKDYT-k9zGOQ]. >>African Mineral Production, British Geological Survey
("Indium Price Supported by LCD Demand and New Uses for the Metal," 2005) [http://geology.com/articles/indium.shtml]
("Rising Prices and Demand for Zirconium," 2011)
("Gallium: The Slippery Metal," 2009) [http://seekingalpha.com/article/117894-gallium-the-slippery-metal]
(USGS, 2012) [http://minerals.usgs.gov/minerals/pubs/commodity/zirconium/].
("Supply Shortages of Zircon to Continue, Further Price Rises Unsustainable," 2011) [http://www.prnewswire.com/news-releases/supply-shortage-of-zircon-to-continue-further-price-rises-unsustainable-124015944.html]
(Gruber, Paul W., 2011) [http://www.eenews.net/assets/2011/07/27/document_gw_02.pdf]