 Discovery Information
|
| Who: Sir Humphrey Davy |
| When: 1808 |
| Where: England |
|
| Name Origin
|
| From Magnesia ancient city in Asia Minor. |
| "Magnesium" in different languages. |
|
| Sources
|
| Although magnesium is found in over 60 minerals, only dolomite (CaMg(CO3)2), magnesite (MgCO3), brucite (Mg(OH)2), carnallite (KMgCl3 - 6(H2O)), talc, and olivine ((Mg,Fe)2SiO4) are of commercial importance. Usually obtained by electrolysis of melted magnesium chloride found in sea water.
|
| China produces around 60% of the world's magnesium, other important producers are Austria, Poland, Russia, the USA, India, Greece and Canada. Annual production is around 350 thousand tons. |
|
| Abundance
|
| Universe: 600 ppm (by weight) |
| Sun: 700 ppm (by weight) |
| Carbonaceous meteorite: 1.2 x 105 ppm
|
| Earth's Crust: 23000 ppm |
| Seawater: 1200 ppm |
| Human: |
| 270000 ppb by weight |
| 70000 ppb by atoms |
|
| Uses
|
| Used in alloys to make airplanes, missiles, car engine parts, racing bikes and other things that need light metals. Also used in fireplace
bricks, flashbulbs, pigments and filters. Magnesium powder is still used in the manufacture of fireworks and marine flares
where a brilliant white light is required.
|
| Magnesium oxide and other compounds also are used in agricultural, chemical, and construction industries. As a metal, this element's principal use is as an alloying additive to aluminium with these aluminium-magnesium alloys being used mainly for beverage cans.
|
| Magnesium carbonate (MgCO3) powder is also used by athletes, such as gymnasts and weightlifters, to improve the grip on objects - the apparatus or lifting
bar.
|
| Magnesium stearate is a slightly flammable white powder with lubricative properties. In pharmaceutical technology it is used
in the manufacturing of tablets, to prevent the tablets from sticking to the equipment during the tablet compression process
(i.e., when the tablet's substance is pressed into tablet form).
|
|
| History
|
| The name originates from the Greek word for a district in Thessaly called Magnesia. It is related to magnetite (Fe3O4) and manganese, which also originated from this area, and required differentiation as separate substances. See manganese
for this history.
|
| Magnesium is the eighth most abundant element in the earth's crust. It is found in large deposits of magnesite, dolomite,
and other minerals, and in mineral waters, where magnesium ion is soluble. In 1618 a farmer at Epsom in England attempted
to give his cows water from a well. This they refused to drink because of the water's bitter taste. However the farmer noticed
that the water seemed to heal scratches and rashes. The fame of Epsom salts spread. Eventually they were recognised to be
hydrated magnesium sulphate, MgSO4.
|
| Sir Humphry Davy electrolytically isolated pure magnesium metal in 1808 from a mix of magnesia and HgO, and A. A. B. Bussy prepared it in coherent form in 1831. Davy's first suggestion for a name was magnium, but the name magnesium is now used.
|
|
| Notes
|
| Organic magnesium is important in both plant and animal life. |
|
| Hazards
|
| Magnesium metal and alloys are highly flammable in their pure form when molten, as a powder, or in ribbon form. Burning or molten magnesium metal reacts
violently with water. Once ignited it is difficult to extinguish, being able to burn in both nitrogen (forming magnesium nitride), and carbon dioxide (forming magnesium oxide and carbon). Magnesium powder is an explosion hazard.
|
| Magnesium reacts violently with halogens. |
