- About IMA
- Buyers Guide
- Mg Basics
- Mg Applications
- Mg Resources
- Mg Sustainability
What is Magnesium?
Magnesium is the lightest of all commonly used structural materials with a density of 1.7g/cm3 (106.13lb/ft3) approximately 1/3 that of aluminum. It is the 3rd most abundant metallic element in the earth’s crust however, it is rarely found in its pure form due to the fact that it bonds with other elements easily. It was first produced in 1808 in small quantities by Sir Humphrey Davy and industrial production first began in 1886 in Germany. Magnesium was first found in an area of Thessaly/Greece called Magnesia. The ore got its name from this location and can still be found in great quantities there.
Where is Magnesium Found?
Most magnesium comes from seawater which is composed of 0.13 percent of the element in the form of magnesium chloride. It can also be found in natural minerals such as dolomite and magnesite in the form of magnesium oxide. Magnesium can be produced through several different methods such as the electrolytic method, the thermal-reduction method or the most commonly used Pidgeon method. The electrolytic method consists of mixing seawater with lime in settling tanks. Precipitates of magnesium hydroxide fall to the bottom of the tank, are filtered, and mixed with hydrochloric acid. This resulting solution is then exposed to electrolysis which produces magnesium metal.
The metal is cast into ingots for further processing as needed. In the thermal-reduction method, dolomite, magnesite and other magnesium containing ores are broken down through the use of reducing agents. The mixture is heated in a vacuum chamber forming magnesium vapors which later condense into crystals. The crystals are melted, refined and poured into ingots for further processing.
The Pidgeon process is most commonly used for production of magnesium due to the fact that its operation is relatively easy, versatile and has low capital cost. This process is also high in energy consumption and has low productivity. In this process, magnesium is collected from a condenser on the outside of a furnace. High priority magnesium can be attained from the condenser since vapor pressure of impurities that may be in the magnesium are low under the conditions of the tank. The largest producers of magnesium are China, Russia and Canada.
Advantages of Magnesium Use
There are many advantages to using magnesium and its alloys. With the lowest density of all commercial casting alloys, magnesium is 33 percent lighter than aluminum and 75 percent lighter than steel. Despite the lower density, magnesium alloys have a comparable strength to weight ratio to aluminum. Magnesium and its alloys also have a high vibration damping capacity making them an ideal material choice for many high speed applications. Electromagnetic interference reduction is another desirable quality that magnesium can offer as a material. In an increasingly environmentally conscience world, the full recyclability and ample availability of the metal also make it a suitable selection.