- Rare Earth Elements (REEs): Defined as the 15 lanthanides plus scandium (Sc) and yttrium (Y), REEs are critical components in consumer electronics such as televisions, tablet computers, cameras, and mobile phones, and rechargeable hybrid car batteries.
- Platinum-group Elements (PGEs): The PGEs consist of platinum, palladium (Pd), rhodium (Rh), iridium (Ir), osmium (Os), and ruthenium (Ru). They are essential components in industrial machinery, catalytic converters, and fuel cells.
- Fission Elements: Uranium (U), thorium (Th), and plutonium (Pu) are fission elements commonly used in the fuel and energy industries. INFOGRAPHIC: 9 Fascinating Facts About Uranium
Previous blogs have discussed the REEs and the PGEs. Here we discuss a few of the critical metals, sometimes called “rare” metals that do not fall into one of the above categories. Tungsten (W) is known for its strength and high melting point. It is used in electrical, heating, and welding applications, aerospace and defense applications, and in light bulbs, heating elements, and rocket engine nozzles. Tungsten is also used in electrodes because of its conductive properties, and its strength makes it a common metal alloy. Tantalum (Ta) is also known for its strength and high melting point, as well as its ductility. As such, it is also a popular alloying element. Tantalum is used in electronic equipment such as mobile phones, video game systems, and computers, as well as surgical equipment and artificial joints. The metal is used to make capacitors for electronics, to fabricate chemical process equipment, nuclear reactors, aircraft, and missile parts. INFOGRAPHIC: 8 Tantalum Facts Niobium (Nb) is mined together with tantalum and mainly found in niobite (or columbite), columbite-tantalite (Coltan), pyrochlore , and euxenite. Niobium is present in alloys used to make jet engine components, rocket subassemblies, and combustion equipment, oil and gas pipelines, car and truck bodies, and railroad tracks. Superconductive magnets are made with this element. Gallium (Ga) is known for its extremely low melting point—it can be liquid at near room temperature. It is used predominantly in semiconductor applications, including analog integrated circuits, laser diodes and light-emitting diodes, and solar panels. Indium (In) is an electrically conductive element most commonly found in zinc ores. Its primary application is to form transparent electrodes from indium tin oxide (ITO) in semiconductors, LCD screens, photovoltaics, LED lights, lasers, and coatings. Given the essential role of these materials in supporting a country’s infrastructure, economic development and national defense, demand for strategic metals is expected to increase, while supplies will only diminish. This is because strategic metals are sparsely distributed in the Earth’s crust and are usually mined as by-products of precious and base metals mining. Mining investments and operations are driven by the overarching goal of mining for major and precious metals, although dedicated strategic metals mining operations are increasing in response to the shortage. Ore exploration mining to find the best deposits, whether it’s for base metals or strategic metals, remains a challenge for the mining industry. Narrowing the search area requires careful geochemical analysis, which can be accomplished with x-ray-fluorescence (XRF) technology. Field-portable XRF is especially useful in early-stage exploration because it provides in-situ geochemical analysis of outcrops, soils, cuttings, cores and direct samples to determine the likelihood, and if applicable, the potential productivity of a deposit. To gain a better understanding of some of the other challenges the mining industry faces, read Key Issues Facing the Mining Industry in 2014.