Magnesium

Magnesium is the eighth most abundant metal in the earth’s crust and is found in over 60 minerals. Dolomite (CaMg(CO3)2) and magnesite (MgCO3) are currently the two most commercially attractive sources for magnesium production. The current dominant route for magnesium production is via the Pidgeon process, an energy intensive pyrometallurgical route that produces high greenhouse gas emissions. In this process dolomite or magnesite concentrates are calcined. The resulting magnesium oxide is then reduced with silicon in a high temperature retort. Magnesium gas is recovered then subsequently cooled to produce magnesium metal. Magnesium is also produced via the electrolysis of magnesium chloride from brine or seawater, since seawater is the second most abundant cation after sodium.

Magnesium is the third most commonly used structural metal following iron and aluminium. It is used as an alloying element, in die casting, steel desulphurisation and in the production of titanium. It is extensively used in the aircraft and automotive industry due to its alloying properties of producing used in super strong, lightweight aluminium alloys.