Base metals

TUNGSTEN
Tungsten is a dense, steel-gray-to-white transition metal. It has the highest melting point and lowest vapour pressure of all metals. When alloyed with other metals, it increases the metal’s hardness, corrosion-resistance and durability.

The major modern-day use of tungsten chemicals is in the area of catalysts. Since the 1930s, the oil industry has used tungsten in catalysts for treating of crude oils.

Tungsten compounds and alloys have many uses, including:

  • Tool making and machinery - increases hardness and reduces wear on equipment
  • Chemical catalysts - including reducing nitrogen oxide emissions, and converting natural gas to hydrogen gas
  • Semiconductors - tungsten hexafluoride is widely used for depositing metal on semiconductor circuits and circuit boards
  • Electronics - the use of tungsten is also growing in liquid crystal display (LCD) technology
  • Solar power - tungsten compounds are being used as thin film coatings in photovoltaic (PV) cells on solar panels
  • Medical and dental applications - including dental filling materials and X-ray shields
  • Mining and mineral separation processes
  • Lubricants - tungsten disulphide is one of the most lubricous materials known to science and is used to reduce friction and wear; particularly in automotive and aerospace applications
  • Pigments for glazes and enamels

 Emerging uses for tungsten include: 

  • Fuel cell technology - this is a growing industry to achieve higher fuel efficiency and help realize a hydrogen economy; an energy system where solar, wind and fuel energy is stored as hydrogen and available on-demand as electricity. Tungsten-based materials can be used as catalysts, co-catalysts, catalyst supports and electrolytes in different types of fuel cells. Tungsten-based materials are being investigated for automotive proton exchange fuel cells. 
  • Gas sensors - tungsten oxide has a unique property to hold individual water molecules and change the electrical properties. Tungsten oxides are being used in energy saving 'intelligent' windows that can darken and lighten according to sun exposure. 
  • Medical applications - the most active areas of medical polyoxometalates (POMS) research are anti-viral and anti-tumoral. A third area which is quickly emerging is in the area of antibiotic effectiveness against otherwise resistant strains of bacteria. Tungsten POMS are also being investigated as an agent for insulin control (to help in treatment of diabetes as well as effective weight loss treatments). 
  • Protective applications - including decontamination of chemical warfare agents such as nerve gas and sarin gas, and fibre coatings that are used to make protective clothing and skin-protecting lotions.

MOLYBDENUM
Molybdenum is a silvery white, hard transition metal, mainly used in the steel making industry. It is frequently used in alloy and stainless steels. Its addition enhances the performance of materials under high-stress conditions within an expanded temperature range, and in highly corrosive environments. Molybdenum is also used in catalysts and lubricants.

RARE EARTH ELEMENTS
Rare Earths Elements (REEs) are a set of 17 chemical elements in the periodic table, specifically the 15 lanthanoids plus scandium and yttrium (the latter two are considered REEs since they tend to occur in the same ore deposits as the lanthanoids and exhibit similar chemical properties).

Despite their name, REEs (with the exception of promethium) are relatively plentiful in the earth's crust, with cerium being the 25th most abundant element at 68 parts per million (similar to copper). However, REEs are typically dispersed and not often found in concentrated and economically exploitable forms. It is the scarcity of these minerals that led to the term 'rare earth.'

The names of the 17 REEs are: scandium, yttrium, lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium and lutetium.

The 'Big 5' rare earths are their uses are presented below.

  • Praseodymium (light REE) - Praseodymium's primary use is as an alloying agent with magnesium to create high-strength metals that are used in aircraft engines. Praseodymium also makes up about 5% of Misch metal, a material used to make flints for lighters. Praseodymium forms the core of carbon arc lights which are used in the motion picture industry for studio lighting and projecter lamps. Praseodymium is also added to fiber optic cables as a doping agent where it is used as a signal amplifier.
  • Neodymium (light REE) - Neodymium makes up about 18% of Misch metal (used to make flints for lighters). It is also a component of didymium glass, which is used to make certain types of welders' and glass blowers' goggles. Neodymium is added to glass to remove the green colour caused by iron contaminants. It can also be added to glass to create violet, red or gray colours. Some types of glass containing neodymium are used by astronomers to calibrate devices called spectrometers and other types are used to create artificial rubies for lasers. Some neodymium salts are used to colour enamels and glazes.
  • Europium (heavy REE) - Europium is the most reactive of the REEs. There are no commercial applications for europium metal, although it has been used to dope some types of plastics to make lasers. Since it is a good absorber of neutrons, europium is being studied for use in nuclear reactors. Europium oxide is widely used as a red phosphor in television sets and as an activator for yttrium-based phosphors.
  • Terbium (heavy REE) - Terbium is used to dope some types of solid-state devices and, along with zirconium dioxide, as a crystal stabilizer in fuel cells that operate at high temperatures. Terbium oxide can potentially be used as an activator for green phosphors in television tubes. Sodium terbium borate, another terbium compound, is used to make laser light.
  • Dysprosium (heavy REE) - There are no commercial applications for 'straight' dysprosium. Since it easily absorbs neutrons and has a high melting point, dysprosium might be alloyed with steel for use in nuclear reactors. When combined with vanadium and other REEs, dysprosium is used as a laser material. Dysprosium oxide is combined with nickel and added to a special cement to cool nuclear reactor rods.

REEs are not exchange-traded in the same way that precious and non-ferrous metals are. Instead, they are sold on the private market, which makes their prices difficult to monitor and track. However, prices are published periodically on websites such as www.mineralprices.com. The 17 elements are not usually sold in their pure form, but instead are distributed in mixtures of varying purity, e.g., 'neodymium metal >99.5%.'

Base metals resource statement