What Is Germanium and Where Do I Use It?
- Germanium is a chemical element with symbol Ge and atomic number 32. It is a brittle, silvery-white semi-metal.
- As is the case for many minor metals, germanium does not occur in its elemental state in nature, but is found as a trace metal in a variety of minerals and ores. Only a few minerals of germanium have been identified, the major one being germanite.
- Germanium ores are very rare. They are found in small quantities as the minerals germanite and argyrodite.
- Today, germanium is extracted as a by-product of zinc production and from coal fly ash. It is estimated that 75% of worldwide production of germanium is sourced from zinc ores, mainly the zinc sulfide mineral sphalerite, and 25% from coal.
- The three major uses of germanium are in fibre optics, infrared optics and polymerisation catalysts for PET plastics. Use in electronic applications and solar cells also play and important role.
- Both germanium and germanium oxide are transparent to infrared radiation and so are used in infrared spectroscopes. For this reason, it is used to make lenses and windows for IR radiation. These are mainly used in military applications such as night-vision devices. Uses outside of the military are in advanced firefighting equipment, satellite imagery sensors and medical diagnostics.
Where is Germanium Produced?
- The major worldwide producer of germanium is China; it is responsible for around 60% of total production. It is estimated that 60% of this is produced from zinc ores and 40% from coal fly ash. The remaining production of germanium comes from Canada, Finland, Russia and the United States.
- A stockpile of germanium is known to be held by the US Defence Logistics Agency; as of 31 December 2011, the total inventory of germanium was 16,362 kg.d The Chinese State Reserve Bureau has also announced plans to buy 20 tonnes of germanium metal for its national stockpile.
- Two of the major germanium producing countries currently impose taxes upon the export of germanium; Russia imposes a tax on the export of germanium waste and scrap (6.5%) and China imposes a tax on the export of germanium oxides (5%)
- Various alternatives are available for the substitution of germanium in its applications, however many of these substitutes result in a loss of performance and are therefore not optimal.