Mg • Atomic Number 12
Magnesium
Magnesium belongs to the alkaline earth metals and is one of the ten most abundant elements in the Earth’s crust. It occurs in numerous minerals and is essential for all cellular life. The human body contains about 24 grams of magnesium, half of which is stored in the bones, a quarter in the muscles, and the rest in the blood and intracellular spaces. In plants, magnesium is found in the cell walls.
Magnesium is chemically inert at room temperature, neither reacting with oxygen nor water, but it is attacked by acids. When burned, magnesium produces an intensely bright white flame and forms magnesium oxide.
Magnesium shares many properties with aluminum but is about one-third lighter and has a significantly lower density.
It is the lightest structural metal and is used in construction, aerospace, and medicine.
In finely divided form, magnesium burns in air with an intense white light.
The largest magnesium producers are China, Russia, Turkey, and Austria.
Key players in China include Magontec Xinguang and Shanxi Yinguang Huasheng Magnesium. Outside China, Dead Sea Magnesium from Israel and VSMPO-AVISMA in Russia are significant.
Magnesium is considered a critical raw material by the EU and South Korea. The USA and Japan classify magnesium as strategic.
The first indications of magnesium date back to the 17th century when English farmers encountered bitter-tasting water. It was later found to contain magnesium sulfate, also known as “Epsom salt.”
Magnesium was first identified in 1755 by Joseph Black in Edinburgh. The first synthesis of metallic magnesium was achieved by Sir Humphry Davy in London in 1808. In 1831, Antoine-Alexandre-Brutus Bussy (École de Pharmacie in Paris) isolated metallic magnesium.
The name magnesium is derived from Magnesia, a region in Thessaly, Greece, where the mineral magnesia alba was first discovered.
The first commercial production of magnesium by electrolysis began as early as 1866 at the German Chemical Factory Griesheim-Elektron. The military build-up during World War I significantly increased demand for magnesium for flares, incendiary bombs, and lightweight metal alloys.
The Dow Chemical Company (USA) became a pioneer in extracting magnesium from seawater (brine).
During World War II, magnesium production surged dramatically as demand for aircraft, ammunition, and incendiary bombs skyrocketed.
Pidgeon Process (1941): Canadian scientist Lloyd Pidgeon developed the thermal reduction process (using dolomite and ferrosilicon), which was later adopted by China.
By the end of the 20th century, China expanded the use of the Pidgeon Process, leveraging inexpensive coal energy. The Chinese province of Shanxi became the center of low-cost magnesium production.
Today, China dominates global magnesium production, supplying over 85 percent of worldwide demand.
In 2021, production cuts in China caused prices to surge by 400 percent and sparked numerous diversification initiatives in Western industrial countries.
The global annual consumption of magnesium is about one million tons and is steadily increasing. Magnesium is the easiest structural metal to work with.
Since pure magnesium has low structural strength, it is mainly used in the form of alloys—typically containing ten percent or less of aluminum, zinc, and manganese—to improve its hardness, tensile strength, as well as casting, welding, and machinability.
Magnesium alloys have diverse applications. About half of the global magnesium demand comes from the automotive and aerospace industries. With the rise of electromobility, magnesium demand could increase significantly due to its potential for substantial weight savings. Weight reduction is also a key factor in aerospace.
Additionally, magnesium is a strong reducing agent used in the production of other metals such as titanium, zirconium, and hafnium from their compounds.
Magnesium is also used in explosives and pyrotechnics.
The raw materials for magnesium production are usually the minerals dolomite, magnesite, and carnallite, as well as seawater.
Most magnesium is produced via the Pidgeon process. In this method, calcined dolomite is heated with fluorspar and ferrosilicon under vacuum to temperatures above 1,000 °C. The resulting gaseous magnesium condenses and is further purified by vacuum distillation.
The second process is molten salt electrolysis, where magnesium chloride extracted from seawater is heated with the addition of salts (such as sodium chloride). Magnesium collects on the molten salt surface.
Magnesium is found in minerals like serpentine, chrysotile, and meerschaum. Seawater contains about 0.13 percent magnesium, mainly as dissolved chloride. As carbonate, it occurs in the form of magnesite and dolomite, as well as in many common silicates such as talc, olivine, and most types of asbestos.
Magnesium is commercially produced by the electrolysis of molten magnesium chloride (MgCl₂), primarily obtained from seawater, and by direct reduction of its compounds with suitable reducing agents.
China dominates global production with an 85 to 90 percent share. Following China is Russia, where VSMPO-AVISMA produces magnesium from magnesite in the Ural region.
Austria plays a smaller yet strategically important role for the EU in magnesium supply, being active in magnesium scrap recycling.
About 30 percent of the global magnesium demand is met through recycling.
Aluminum and zinc can replace magnesium in cast and forged products.
The relatively low weight of magnesium is an advantage over aluminum and zinc in most applications of cast and forged products; however, its higher cost is a disadvantage compared to these substitutes.
Calcium carbide can be used instead of magnesium for desulfurizing iron and steel. Magnesium is preferred for desulfurization because calcium carbide produces acetylene in the presence of water.
Aluminum oxide, chromite, and silicon dioxide replace magnesium oxide in some refractory applications.
Critical and Strategic Metals
