See also: Mg
Magnesium is a alkaline-earth Métal. It is the eighth most abundant element of the Earth's crust, the third metal behind the Aluminum and the Fer. It is also the third component of the salts dissolved in the Sea water.
HistoryThe name magnesium comes from the Greek name of a district of Thessalie called Magnesia. This city was extremely rich in magnesium and this in various forms. It was used as salt and in other forms.
In England, Joseph Black recognized magnesium like an element in 1755, and Humphry Davy isolated the pure metal form by electrolysis in 1808 starting from a mixture from Magnésie and oxide HgO mercury.
CharacteristicsMagnesium is a having metal of weak mechanical characteristics but is very light (a third lighter than aluminum), of white-silver plated aspect, and which tarnishes slightly once exposed to the air.
In solution, it forms Mg2+ ions.
It ignites with difficulty in the form of block, but very easily if it is tiny room in small chips. Out of powder, this metal warms up by oxidation and ignites when it is exposed to the air. It burns with a very luminous luminous flame, from where its use for the flashes at the beginnings of the Photographie.
IndustryMagnesium is mainly used in the Alliage S Aluminum - magnesium. Is also used it to facilitate the elimination of the Soufre in the metallurgy of iron and the Acier S. It allows the manufacture of nodular cast iron in which graphite is in the form of nodules (spheroids). Cast iron (metallurgy)
Magnesium is largely employed in alloys containing aluminum intended for the plastic deformation, being used for the manufacture of sections, or the drink quills, which consumes significant amounts of them.
The lightness of magnesium and its mechanical characteristics make it invaluable for particular uses as the realization of small resistant cases, of cases of laptops or top-of-the-range cameras. Used mainly in aeronautics, the magnesium alloys start to extend in other branches of industry, in particular in auto industry where the policy is currently to minimize the weight of the vehicles in order to reduce consumption while carburizing. However, making of these alloys at base magnesium is difficult and dangerous since finely divided magnesium (droplets of liquid magnesium, powders magnesium) can ignite or explode with the contact with the atmosphere or of water.
Magnesium is also used as reagent in chemical industries and pharmaceutical.
Alloys containing magnesium are also used for to carry out castings for the Automobile S and the machines.
Alloys magnesium-calcium are used in the metallurgy of the Plomb (for the débismuthage).
Compounds of magnesium, mainly the Magnesia MgO, are employed like refractory Material for the garnishing of furnaces (glass, cement), in the metallurgy of the Fer, the Acier non-ferrous or other metals.
The magnesia and others made up are employed in agricultural, chemical industries and of the building, like in the sport, in particular in gymnastics and climbing.
MedicineMagnesium is very much used in medicine and pharmacy. He plays a very important part in the food. Many disorders can follow a lack of magnesium: depression and distresses, muscular diabetes, spasms, cardiovascular cramps, disorders, raised blood pressure and osteoporosis. It takes an active part in the transmission of the data between the neurons.
The contribution recommended daily is estimated at 300 magnesium Mg per day (double for the sportsmen or the expectant mothers) or 6 mg/kg of weight.
The body does not produce magnesium. Excessive consumption would be eliminated naturally by the organization. The ingestion of great quantities of magnesium shows Diarrhée S. magnesium is effectively filtered by the kidneys in the adult, but poisoning by magnesium excess can exist at the child and in the case of impaired renal functions.
The magnesium hydroxide (Mg (OH) 2), obtained while making react the sodium hydroxide on the magnesium salt, is employed in medicine like Laxatif (magnesia milk), like in the refining of the Sucre.
Food sources of magnesiumThe seafood (except for the Winkle X) contains 410 Mg for 100 G, it is without any doubt the food richest in magnesium.
They are followed closely by the cocoa with 150 to 400 Mg for 100 G) and complete cereals containing 100 with 150 Mg for 100 G. On the other hand the acid Polysaccharide S and phytic that they contain harm their absorption, especially in the case of the wholewheat bread with the Levure, but not in the case of the wholewheat bread with the Levain which destroys these acids partially.
The spinach S contain of 50 with 100 Mg for 100 G, but contain Oxalic acid which gene also their assimilation.
Lastly, the fish, the meat offals and the bolted cereals contain of 25 with 50 magnesium Mg for 100 G.
PlantsMagnesium constitutes one of the basic elements of the Chlorophylle, where he plays a part similar to that of iron in the Hémoglobine of blood.
Layers and production of metalOne finds magnesium everywhere on planet, in various forms (magnesite, dolomite, carnallite). One can extract magnesium from the Dolomite for example (as in the the Pyrenees, where was a factory Pechiney of production of magnesium by electrometallurgy, proceeded Magnétherm). One can also extract magnesium from the sea water (content: 1,3 kg/m), even in certain lakes which can contain some until 35 kg/m.
From the various ores or brines containing of magnesium, in the form of chloride, from carbonate, oxide, metal is extracted by processes from the type electrolysis or electrometallurgy
- table of rich foods in magnesium
- a video on the combustion of magnesium
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