Tungsten

Tungsten, also known as wolfram, is a chemical element with the symbol W and atomic number 74.

Tungsten occurs naturally on Earth in chemical compounds known as wolframite ((Fe, Mn)WO4), scheelite (CaWO4), huebnerite (MnWO4) and ferberite (FeWO4). The metal is obtained commercially by the reduction of tungsten oxide with hydrogen or carbon.

Tungsten has the highest melting point of all elements except carbon – around 3400°C. It also has excellent high temperature mechanical properties and the lowest expansion coefficient of all metals. A temperature of about 5700°C is needed to bring tungsten to boil - which corresponds approximately to the temperature of the sun’s surface. With a density of 19.25 g/cm3, tungsten is also among the heaviest metals. Its electrical conductivity at 0°C is about 28% of that of silver which itself has the highest conductivity of all metals.

Pure tungsten is a shiny white metal and in its purest form is quite pliant and can easily be processed. Usually, however, it contains small amounts of carbon and oxygen, which give tungsten metal its considerable hardness and brittleness.

Today, the largest use for tungsten is in cemented carbide (or hardmetals as they are often called) – wear resistant materials used by the metalworking, mining, oil, and construction industries.

Tungsten Market

The tungsten market is relatively opaque due to its concentrated structure, with a small number of tungsten concentrate suppliers/consumers outside of China. Typically sales occur under long-term contracts, and it is commonplace for customers to also have financial involvement in tungsten supply sources.

Prices for tungsten concentrates tend to follow the same trend as prices for ammonium paratungstate (APT), which is the key intermediary product in the tungsten supply chain. APT prices for spot market transactions are published by several data providers with prices established through surveys of buyers, sellers and other industry participants. APT Prices are quoted on the basis of metric tonne units which is equal to 10 kg. tungsten per tonne of product.