Mgcl2 Magnesiumchlorid Hexahydrat Industriequalität Magnesiumchlorid Hellgelb/ Weiße Flocke MgCl2 6H2O 2827200000 2cm-8cm

Magnesium chloride   is the name for the   chemical compound   with the   formula   MgCl ₂   and its various   hydrates   MgCl ₂ (H ₂ O) _x . Anhydrous MgCl ₂   contains 25.5% elemental magnesium by mass. These salts are typical ionic   halides , being highly soluble in water. The hydrated magnesium chloride can be extracted from   brine   or   sea water . In North America, magnesium chloride is produced primarily from   Great Salt Lake   brine. It is extracted in a similar process from the   Dead Sea   in the   Jordan Valley . Magnesium chloride, as the natural mineral   bischofite , is also extracted (by solution mining) out of ancient seabeds, for example, the   Zechstein   seabed in northwest Europe. Some magnesium chloride is made from solar evaporation of seawater.   Anhydrous   magnesium chloride is the principal precursor to magnesium metal, which is produced on a large scale. Hydrated magnesium chloride is the form most readily available.

 

Several hydrates are known with the formula MgCl ₂ (H ₂ O) _x , and each loses water at higher temperatures:   x   = 12 (−16.4 °C), 8 (−3.4 °C), 6 (116.7 °C), 4 (181 °C), 2 (about 300 °C). In the hexahydrate, the Mg ²⁺   is also   octahedral , but is coordinated to six water   ligands . The thermal dehydration of the hydrates MgCl ₂ (H ₂ O) _x   ( x   = 6, 12) does not occur straightforwardly.     Anhydrous MgCl ₂   is produced industrially by heating the chloride salt of hexammine complex [Mg(NH ₃ ) ₆ ] ²⁺ .

As suggested by the existence of some hydrates, anhydrous MgCl ₂   is a   Lewis acid , although a weak one.

In the   Dow process , magnesium chloride is regenerated from magnesium hydroxideby acid:

It can also be prepared from   magnesium carbonate   by a similar reaction.

Derivatives with tetrahedral Mg ²⁺   are less common. Examples include salts of ( N(C ₂ H ₅ ) ₄ ) ₂ MgCl ₄   and   adducts   such as MgCl ₂ ( TMEDA ).

 

Dust and erosion control

Magnesium chloride is one of many substances used for dust control,   soil stabilization , and   wind erosion   mitigation. When magnesium chloride is applied to roads and bare soil areas, both positive and negative performance issues occur which are related to many application factors.

Catalyst support

Ziegler-Natta catalysts , used commercially to produce   polyolefins , contain MgCl ₂   as a   catalyst support .     The introduction of MgCl ₂   supports increases the activity of traditional catalysts and allowed the development of highly stereospecific catalysts for the production of   polypropylene .

Ice control

Magnesium chloride is used for low-temperature de-icing of   highways ,   sidewalks , and   parking lots . When highways are treacherous due to icy conditions, magnesium chloride helps to prevent the ice bond to the pavement, allowing   snow   plows to clear the roads more efficiently.

Magnesium chloride is used in three ways for pavement ice control: Anti-icing, when maintenance professionals spread it onto roads before a snow storm to prevent snow from sticking and ice from forming; prewetting, which means a liquid formulation of magnesium chloride is sprayed directly onto salt as it is being spread onto roadway pavement, wetting the salt so that it sticks to the road; and pretreating, when magnesium chloride and salt are mixed together before they are loaded onto trucks and spread onto paved roads. Calcium chloride damages concrete twice as fast as magnesium chloride. It should be noticed that the amount of magnesium chloride is supposed to be controlled when it is used for de-icing as it may cause pollution to the environment.

Nutrition and medicine

Magnesium chloride is used in   nutraceutical   and   pharmaceutical preparations .

Cuisine

Magnesium chloride ( E511 ) is an important   coagulant   used in the preparation of   tofu   from   soy milk .

In Japan it is sold as   nigari   ( derived from the Japanese word for "bitter"), a white powder produced from   seawater   after the   sodium chloride   has been removed, and the water evaporated. In China, it is called   lushui   .

Nigari or Iushui is, in fact, natural magnesium chloride, meaning that it is not completely refined (it contains up to 5%   magnesium sulfate   and various minerals). The crystals originate from lakes in the Chinese province of   Qinghai , to be then reworked in Japan. Millions of years ago, this region was home to an   ancient ocean   that gradually dried up and of which only salty lakes with   brackish water   saturated with salt where magnesium chloride crystallizes remain today.

It is an inexpensive   dietary supplement   providing magnesium, hence its interest in view of a general deficit in our current consumption (to be in full health, the human body must in particular benefit from a balance between   calcium   and   magnesium ). It is also an ingredient in baby formula milk.