Material of the Month: Germanium

Material of the Month: Germanium

Germanium is a hard, brittle semimetal that first came into use a half-century ago as a semiconductor material in radar units and as the material from which the first transistor was made. Today, germanium is mainly used in electronics and solar applications, fiber-optic systems, infrared optics, polymerization catalysts, and other uses (such as chemotherapy, metallurgy, and phosphors). Germanium-containing infrared optics were primarily for military use, but the commercial applications for thermal-imaging devices that use germanium lenses have increased during the past few years.

In the earth crust, germanium seldom appears in high concentrations. Due to its highly dispersive nature, it is mostly recovered as a byproduct of zinc smelting, although it has also been recovered at some copper smelters and from the fly ash of coal-burning industrial powerplants.

Production

Germanium is a dispersed element. In nature, it never exists as the native metal and is only rarely found in commercial quantities in the few minerals in which it is an essential component. Rather, it occurs in trace amounts in many minerals, including some of the common metallic ore minerals. Most Germanium is recovered as a byproduct of zinc smelting, but it has also been recovered at some copper smelters and from the fly ash of coal-burning industrial powerplants. Around half of total known resources are located in Russia and one quarter is located in China. The world average production of refined germanium is dominated by China, followed by Russia with another major contribution. United States and Japan and the Ukraine produce other minor fractions (see figure below).

An estimated amount of 30% of global germanium production is supplied by recycling, mostly from scrap generated during the manufacture of fibre-optic cables and infrared optics. Due to the high value of refined germanium, this scrap is reclaimed and fed back into the production process at a rate of 60%. However, only a small margin of Germanium is recycled from end-of-life products, because of its high dispersion in most products and application in very low quantities.

Depending on the application, Germanium can be substituted by other materials such as silicon in some electronic applications. However, substitution often results in a loss of performance and is therefore not optimal.

 

Potential issues

While Germanium is generally a non-toxic element, the ecological footprint of GE recovery from coal starts to get more attention. Barring a large increase in demand, the production, use, and recycling/disposition of germanium appear to be sustainable. No deleterious health or environmental effects are likely to be associated with its production or use.

 

Sources: 

(Melcher, F. and Buchholz, P., 2013)
Study on the EU’s list of Critical Raw Materials (2020)
USGS Open-File Report, Mineral Commodity Profiles: Germanium
USGS Mineral Commodity Summaries, Germanium