'''Magnesium''' ({{pronEng|mægˈniːziəm}}) is a [[chemical element]] with the symbol '''Mg''', the [[atomic number]] 12, and an [[atomic mass]] of 24.31. Magnesium is the ninth most abundant element in the universe by mass. It constitutes about 2% of the [[Earth]]'s [[Crust (geology)|crust]] by mass,<ref name="Abundance"/> and it is the third most abundant element dissolved in [[seawater]]. Magnesium ions are essential to all living cells, and is the 11th most abundant element by mass in the human body. The free element (metal) is not found in nature. Once produced from magnesium salts, this [[alkaline earth metal]] is used as an [[alloy]]ing agent to make [[aluminium]]-magnesium alloys, sometimes called "[[magnalium]]" or "magnelium".
== Notable characteristics ==
Elemental magnesium is a fairly strong, silvery-white, light-weight metal (two thirds the density of [[aluminium]]). It [[tarnish]]es slightly when exposed to air, although unlike the alkaline metals, storage in an oxygen free environment is unnecessary because magnesium is protected by a thin layer of oxide which is fairly impermeable and hard to remove. Like its lower [[periodic table group]] neighbor [[calcium]], magnesium reacts with water at room temperature, though it reacts much more slowly than calcium. When it is submerged in water, [[hydrogen]] bubbles will almost unnoticeably begin to form on the surface of the metal, though if powdered it will react much more rapidly. Magnesium also reacts with [[hydrochloric acid]] (HCl) and produces heat and hydrogen when added to it. The magnesium will begin to bubble and become hot – too hot to touch comfortably. The reaction will occur faster with higher temperatures (see precautions).
'''Magnesium''' is a [[chemical element]] with symbol '''Mg''' and [[atomic number]] 12. It is a shiny gray solid which bears a close physical resemblance to the other five elements in the second column (Group 2, or [[alkaline earth metals]]) of the [[periodic table]]: they each have the same [[electron]] configuration in their outer electron shell to explain their similar crystal structure.
Magnesium is a highly flammable metal, but while it is easy to ignite when powdered or shaved into thin strips, it is difficult to ignite in mass or bulk. 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]]). When it burns in air, Magnesium produces a brilliant white light. Thus magnesium powder ([[flash powder]]) was used as a source of illumination in the early days of [[photography]]. Later, magnesium ribbon was used in electrically ignited flash bulbs. Magnesium powder is used in the manufacture of [[fireworks]] and marine [[flare (pyrotechnic)|flare]]s where a brilliant white light is required.
Magnesium is the ninth most abundant element in the universe.<ref>{{Housecroft3rd|pages=305–306}}</ref><ref>{{cite book|last = Ash|first = Russell|title = The Top 10 of Everything 2006: The Ultimate Book of Lists|publisher = Dk Pub|date = 2005|url = http://plymouthlibrary.org/faqelements.htm|isbn = 0-7566-1321-3}}</ref> It is synthesized in large, aging [[star]]s from the sequential addition of three [[Helium nucleus|helium nuclei]] to a [[carbon]] nucleus. When such a star explodes as a [[supernova]], much of its magnesium is expelled into the [[interstellar medium]], where it can be recycled into new star systems. Consequently, magnesium is the eighth most abundant element in the [[Earth's crust]]<ref name="Abundance" /> and the fourth most common element in the Earth (below [[iron]], [[oxygen]] and [[silicon]]), making up 13% of the planet's mass and a large fraction of the planet's [[Mantle (geology)|mantle]]. It is the third most abundant element dissolved in seawater, after [[sodium]] and [[chlorine]].<ref>{{cite news|url=http://www.seafriends.org.nz/oceano/seawater.htm#composition|title=The chemical composition of seawater|author=Anthoni, J Floor|date=2006|work=seafriends.org.nz}}</ref>
Magnesium compounds are typically white crystals. Most are soluble in water, providing the sour-tasting magnesium ion Mg<sup>2+</sup>. Small amounts of dissolved magnesium ion contributes to the tartness and taste of natural waters. Magnesium ion in large amounts is an ionic laxative, and magnesium sulfate ([[Epsom salts]]) is sometimes used for this purpose. So-called "[[Milk of Magnesia|milk of magnesia]]" is a water suspension of one of the few insoluble magnesium compounds: magnesium hydroxide. The undissolved particles give rise to its appearance and name. Milk of magnesia is a mild base and is commonly used as an antacid.
Magnesium only occurs naturally in combination with other elements, where it invariably has a +2 [[oxidation state]]. The free element (metal) can be produced artificially, and is highly reactive (though once produced, it is coated in a thin layer of oxide, which partly inhibits this reactivity - see [[Passivation (chemistry)|passivation]]). The free metal burns with a characteristic brilliant-white light, making it a useful ingredient in flares. The metal is now obtained mainly by [[electrolysis]] of magnesium [[salts]] obtained from [[brine]]. In commerce, the chief use for the metal is as an [[alloy]]ing agent to make [[aluminium]]-magnesium alloys, sometimes called ''[[magnalium]]'' or ''[[magnalium|magnelium]]''. Since magnesium is less dense than aluminium, this alloy is prized for its properties of lightness combined with strength.
== Applications ==
===As the metal===
Magnesium is the third most commonly used structural metal, following [[steel]] and [[aluminium]].
Magnesium is the eleventh most abundant element by mass in the [[human body]]. Its [[ions]] are essential to all cells.{{clarify|reason=Why? The reasons for this observation (which I don't dispute) are unstated or inadequately stated and need explanation. Also this statement needs a source|date=March 2015}}{{citation needed|date=March 2015}}. They interact with [[polyphosphate]] compounds such as [[Adenosine triphosphate|ATP]], [[DNA]], and [[RNA]]. Hundreds of enzymes require magnesium ions to function. Magnesium compounds are used medicinally as common laxatives, antacids (e.g., milk of magnesia), and to stabilize abnormal nerve excitation or blood vessel spasm such as in [[eclampsia]]. Magnesium ions are sour to the taste, and in low concentrations they help impart a natural tartness to fresh mineral waters. Magnesium is the metallic ion at the center of [[chlorophyll]], and is a common additive to [[fertilizer]]s.<ref>{{cite web|url=http://www.mg12.info|title=Magnesium in health|publisher=magnesium.com |accessdate=10 October 2013}}</ref>
Magnesium compounds, primarily [[magnesium oxide]], are used mainly as [[refractory]] material in [[furnace]] linings for producing [[iron]], [[steel]], nonferrous metals, [[glass]] and [[cement]]. 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 can]]s.
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== Characteristics ==
Magnesium, in its purest form, can be compared with aluminium, and is strong and light, so it is used in several high volume part manufacturing applications, including automotive and truck components. Specialty, high-grade car wheels of magnesium alloy are called "[[Magnesium alloy wheel|mag wheels]]". In 1957 a [[Corvette]] SS, designed for racing, was constructed with magnesium body panels. Porsche's all-out quest to decrease the weight of their racecars led to the use of magnesium frames in the famous 917/053 which won Le Mans in 1971, and still holds the absolute distance record. The 917/30 Can-Am car also featured a magnesium spaceframe, helping it to make the most of its prodigious 1100-1500hp. [[Volkswagen]] has used magnesium in its engine components for many years. For a long time, [[Porsche]] used magnesium alloy for its [[engine block]]s due to the weight advantage. There is renewed interest in magnesium engine blocks, as featured in the 2006 [[BMW]] 325i and 330i models. The BMW engine uses an aluminium alloy insert for the cylinder walls and cooling jackets surrounded by a high temperature magnesium alloy AJ62A. The application of magnesium AE44 alloy in the 2006 Corvette [[Z06]] engine cradle has advanced the technology of designing robust automotive parts in magnesium. Both of these alloys are recent developments in high temperature low [[Creep (deformation)|creep]] magnesium alloys. The general strategy for such alloys is to form [[intermetallic]] precipitates at the [[crystallite|grain boundaries]], for example by adding [[mischmetal]] or [[calcium]].<ref>{{cite paper |title=Tensile and Compressive Creep of Magnesium-Aluminum-Calcium Based Alloys |format=PDF |date=2001 |author=Alan A. Luo and Bob R. Powell |publisher=Materials & Processes Laboratory, General Motors Research & Development Center |accessdate=2007-08-21 |url=http://doc.tms.org/ezmerchant/prodtms.nsf/productlookupitemid/01-481x-137/%24FILE/01-481X-137F.pdf}}</ref> New alloy development and lower costs, which are becoming competitive to aluminium, will further the number of automotive applications.
[[Image:Magnesium-products.jpg|thumb|left|Products made of magnesium: firestarter and shavings, sharpener, magnesium ribbon]]
=== Physical properties ===
The second application field of magnesium is electronic devices. Due to low weight, good mechanical and electrical properties, magnesium is widely used for manufacturing of mobile phones, laptop computers, cameras, and other electronic components. Magnesium is even used to make some higher end [[yo-yo]]s, such as the [[Duncan Freehand Mg]].
Elemental magnesium is a gray-white lightweight metal, two-thirds the density of aluminium. It [[tarnish]]es slightly when exposed to air, although, unlike the other [[alkali metal]]s, an oxygen-free environment is unnecessary for storage because magnesium is protected by a thin layer of oxide that is fairly impermeable and difficult to remove. Magnesium reacts with water at room temperature, though it reacts much more slowly than the similar earth alkali metal calcium. When submerged in water, [[hydrogen]] bubbles almost unnoticeably begin to form on the surface of the metal—though, if powdered, it reacts much more rapidly. The reaction occurs faster with higher temperatures (see precautions). Magnesium's ability to react with water can be harnessed to produce energy and run a [[Magnesium injection cycle|magnesium-based engine]]. Magnesium also reacts exothermically with most acids, such as [[hydrochloric acid]] (HCl). As with aluminium, zinc, and many other metals, the reaction with HCl produces the chloride of the metal and releases hydrogen gas. Magnesium has both the lowest melting and the lowest boiling points of any of the alkali earth metals, at {{convert|923|K|°F}} and {{convert|1363|K|°F}}, respectively.<ref>http://www.ptable.com/#Property/State</ref>
=== Chemical properties ===
Historically, magnesium was one of the main aerospace construction metals and was used for German military aircraft as early as World War I and extensively for German aircraft in World War II. The Germans coined the name 'Elektron' for magnesium alloy which is still used today. Due to perceived hazards with magnesium parts in the event of fire, the application of magnesium in the commercial aerospace industry was generally restricted to engine related components. Currently the use of magnesium alloys in aerospace is increasing, mostly driven by the increasing importance of fuel economy and the need to reduce weight. The development and testing of new magnesium alloys notably Elektron 21 which has successfully undergone extensive aerospace testing for suitability in both engine, internal and airframe components. European Community runs three R&D magnesium projects in Aerospace priority of Six Framework Program.
Magnesium is a highly [[flammability|flammable]] metal, especially when powdered or shaved into thin strips. It is, however, difficult to ignite in mass or bulk. Once ignited, it is difficult to extinguish, being able to burn in [[nitrogen]] (forming [[magnesium nitride]]), [[carbon dioxide]] (forming [[magnesium oxide]], and [[carbon]]) and water (forming magnesium oxide and hydrogen). This property was used in incendiary weapons used in the [[firebombing]] of cities in [[World War II]], the only practical [[civil defense]] being to smother a burning flare under dry sand to exclude the atmosphere. On burning in air, magnesium produces a brilliant-white light that includes strong ultraviolet. Thus, magnesium powder ([[flash powder]]) was used as a source of illumination in the early days of [[photography]]. Later, magnesium ribbon was used in electrically ignited flashbulbs. Magnesium powder is used in the manufacture of [[fireworks]] and marine [[flare]]s where a brilliant white light is required. Flame temperatures of magnesium and magnesium alloys can reach {{convert|3100|°C|K °F|abbr=on}},<ref name="Dreizin, Edward L.; Berman, Charles H. and Vicenzi, Edward P. 2000 30">{{cite journal|title=Condensed-phase modifications in magnesium particle combustion in air|author=Dreizin, Edward L.|author2=Berman, Charles H.|author3=Vicenzi, Edward P.|last-author-amp=yes|journal=Scripta Materialia|volume=122|doi=10.1016/S0010-2180(00)00101-2|date=2000|pages=30–42}}</ref> although flame height above the burning metal is usually less than {{convert|300|mm|in|abbr=on}}.<ref name="DOE">{{cite book
|title = DOE Handbook – Primer on Spontaneous Heating and Pyrophoricity
}}</ref> Magnesium may be used as an ignition source for [[thermite]], a mixture of aluminium and iron oxide powder that is otherwise difficult to ignite.
=== Occurrence ===
[[Image:Magnesium Sparks.jpg|thumb|Magnesium firestarter (in left hand), used with a [[pocket knife]] and flint to create sparks which ignite the shavings]]
{{Category see also|Magnesium minerals}}
Magnesium is the eighth-most-abundant element in the Earth's crust by mass and tied in seventh place with [[iron]] in terms of [[molarity]].<ref name="Abundance">{{cite journal |title=Abundance and form of the most abundant elements in Earth's continental crust |format=PDF |accessdate=15 February 2008|url=http://www.gly.uga.edu/railsback/Fundamentals/ElementalAbundanceTableP.pdf}}</ref> It is found in large deposits of [[magnesite]], [[dolomite]], and other [[mineral]]s, and in mineral waters, where magnesium ion is soluble.
Although magnesium is found in over 60 [[mineral]]s, only [[dolomite]], [[magnesite]], [[brucite]], [[carnallite]], [[talc]], and [[olivine]] are of commercial importance.
*Incendiary use: Magnesium is flammable, burning at a temperature of approximately 2500 K (2200 °C, 4000 °F), and the [[autoignition temperature]] of magnesium is approximately 744 K (473 °C, 883 °F) in air. The extremely high temperature at which magnesium burns makes it a handy tool for starting emergency fires during outdoor recreation. Other related uses include flashlight [[photography]], flares, [[pyrotechnics]], fireworks sparklers, and incendiary bombs.
The {{chem|Mg|2+}} [[cation]] is the second-most-abundant cation in seawater (occurring at about 12% of the mass of sodium there), which makes seawater and sea-salt an attractive commercial source of Mg. To extract the magnesium, [[calcium hydroxide]] is added to [[seawater]] to form [[magnesium hydroxide]] [[precipitate]].
* [[photoengraving|Photoengraved]] plates in the printing industry.
* Combined in alloys, this metal is essential for [[fixed-wing aircraft|airplane]] and [[missile]] construction.
* When used as an alloying agent, this metal improves the mechanical, [[fabrication]] and [[welding]] characteristics of aluminium.
* Additive agent for conventional propellants and used in producing nodular graphite in cast iron.
* Reducing agent for the production of pure [[uranium]] and other metals from their [[salt]]s.
* Magnesium turnings or ribbon are used to prepare [[Grignard reagent]]s, which are useful in [[organic synthesis]]
* Easily reacting with water, it can serve as a [[desiccant]]
Magnesium hydroxide ([[brucite]]) is insoluble in water, so it can be filtered out and reacted with [[hydrochloric acid]] to obtain concentrated [[magnesium chloride]].
* The magnesium ion is necessary for all life (see [[magnesium in biological systems]]), so magnesium salts are an additive for foods, fertilizers (Mg is a component of chlorophyll), and culture media.
From magnesium chloride, [[electrolysis]] produces magnesium.
* [[Magnesium hydroxide]] is used in [[milk of magnesia]], its [[magnesium chloride|chloride]], [[magnesium oxide|oxide]], [[magnesium gluconate|gluconate]] and [[magnesium citrate|citrate]] used as oral magnesium supplements, and its [[magnesium sulfate|sulfate]] ([[Epsom salt]]s) for various purposes in medicine, and elsewhere (see the article for more). Oral magnesium supplements have been claimed to be therapeutic for some individuals who suffer from [[Restless leg syndrome|Restless Leg Syndrome (RLS)]].
* Magnesium borate, magnesium salicylate and magnesium sulfate are used as [[antiseptic]]s.
== Forms ==
* [[Magnesium bromide]] is used as a mild [[sedative]] (this action is due to the [[bromide]], not the magnesium).
=== Alloy ===
* Dead-burned magnesite is used for refractory purposes such as brick and liners in furnaces and converters.
As of 2013, magnesium alloy consumption was less than one million tons per year, compared with 50 million tons of [[aluminum alloy]]s. Its use has been historically limited by its tendency to corrode, high-temperature creep, and flammability.<ref name=giz />
* [[Magnesium carbonate]] (Mg[[carbonate|CO<sub>3</sub>]]) powder is also used by athletes, such as [[gymnastics|gymnasts]] and [[weightlifting|weightlifters]], to improve the grip on objects – the apparatus or lifting bar.
* [[Magnesium stearate]] is a slightly [[fire|flammable]] white [[powder]] with [[lubricant|lubricative]] properties. In [[pharmacology|pharmaceutical]] technology it is used in the manufacturing of [[tablet]]s, 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).
====Corrosion====
* Magnesium sulfite is used in the manufacture of [[paper]] ([[sulfite process]]).
The presence of [[iron]], [[nickel]], [[copper]], and [[cobalt]] strongly activates [[corrosion]]. This is due to their low solid solubility limits (above a very small percentage, they precipitate out as [[intermetallic compound]]s) and because they behave as active [[cathode|cathodic]] sites that reduce water and cause the loss of magnesium.<ref name=giz /> Reducing the quantity of these metals improves corrosion resistance. Sufficient [[manganese]] overcomes the corrosive effects of iron. This requires precise control over composition, increasing costs.<ref name=giz /> Adding a cathodic poison captures atomic hydrogen within the structure of a metal. This prevents the formation of free hydrogen gas, which is required for corrosive chemical processes. The addition of about one-third of a percent of [[arsenic]] reduces its corrosion rate in a salt solution by a factor of nearly ten.<ref name=giz>{{cite web|url=http://www.gizmag.com/stainless-magnesium-corrosion-monash/28856 |title=Stainless magnesium breakthrough bodes well for manufacturing industries |publisher=Gizmag.com |date=29 August 2013|author=Dodson, Brian |accessdate=29 August 2013}}</ref><ref>{{cite doi|10.1016/j.elecom.2013.07.021}}</ref>
* Magnesium phosphate is used to fireproof wood for construction.
* Magnesium hexafluorosilicate is used in mothproofing of [[textile]]s.
====High-temperature creep and flammability====
Research and development eliminated magnesium's tendency toward high-temperature creep by inclusion of [[scandium]] and [[gadolinium]]. Flammability was greatly reduced by introducing a small amount of [[calcium]] into the mix.<ref name=giz />
=== Compounds ===
Magnesium forms a variety of industrially and biologically important compounds, including [[magnesium carbonate]], [[magnesium chloride]], [[magnesium citrate]], [[magnesium hydroxide]] (milk of magnesia), [[magnesium oxide]], [[magnesium sulfate]], and magnesium sulfate heptahydrate ([[Epsom salts]]).
=== Isotopes ===
Magnesium has three stable [[isotope]]s: <sup>24</sup>Mg, <sup>25</sup>Mg and <sup>26</sup>Mg. All are present in significant amounts (see table of isotopes above). About 79% of Mg is <sup>24</sup>Mg. The isotope <sup>28</sup>Mg is radioactive and in the 1950s to 1970s was made commercially by several nuclear power plants for use in scientific experiments. This isotope has a relatively short half-life (21 hours) and so its use was limited by shipping times.
<sup>26</sup>Mg has found application in [[isotope|isotopic]] [[geology]], similar to that of aluminium. <sup>26</sup>Mg is a [[radiogenic]] daughter product of <sup>26</sup>Al, which has a [[half-life]] of 717,000 years. Large enrichments of stable <sup>26</sup>Mg have been observed in the [[Ca-Al-rich inclusions]] of some [[carbonaceous chondrite]] [[meteorite]]s. The anomalous abundance of <sup>26</sup>Mg is attributed to the decay of its parent <sup>26</sup>Al in the inclusions. Therefore, the meteorite must have formed in the [[solar nebula]] before the <sup>26</sup>Al had decayed. Hence, these fragments are among the oldest objects in the [[solar system]] and have preserved information about its early history.
It is conventional to plot <sup>26</sup>Mg/<sup>24</sup>Mg against an Al/Mg ratio. In an [[isochron dating]] plot, the Al/Mg ratio plotted is<sup>27</sup>Al/<sup>24</sup>Mg. The slope of the isochron has no age significance, but indicates the initial <sup>26</sup>Al/<sup>27</sup>Al ratio in the sample at the time when the systems were separated from a common reservoir.
!2011 production <br />([[tonne]]s)<ref>{{cite web |title=2011 Minerals Yearbook, Magnesium|publisher=USGS |accessdate=26 April 2013 |url=http://minerals.usgs.gov/minerals/pubs/commodity/magnesium/myb1-2011-mgmet.pdf}}</ref>
|-
| China || style="text-align:right;"|661,000
|-
| U.S.<ref group=note>Capacity. Production figures withheld to avoid disclosing company proprietary data.</ref>||align="right"|63,500
|-
| Russia ||align="right"| 37,000
|-
| Israel ||align="right"| 30,000
|-
| Kazakhstan ||align="right"| 21,000
|-
| Brazil ||align="right"| 16,000
|-
| Ukraine ||align="right"| 2,000
|-
| Serbia ||align="right"| 1,500
|-
| Total ||align="right"| 832,000
|}
[[File:Mg sheets and ingots.jpg|thumb|Magnesium sheets and ingots]]
[[People's Republic of China|China]] is the dominant supplier of magnesium, with approximately 80% of the world market share. China is almost completely reliant on the [[Silicothermic reaction|silicothermic]] [[Pidgeon process]] (the reduction of the oxide at high temperatures with silicon, often provided by a ferrosilicon alloy in which the iron is but a spectator in the reactions) to obtain the metal.<ref>{{cite web|url=http://www.chinamagnesiumcorporation.com/our-business/magnesium-overview| publisher=China magnesium Corporation| title=Magnesium Overview|accessdate=8 May 2013}}</ref> The process can also be carried out with [[carbon]] at approx 2300 °C:
In the [[United States]], magnesium is obtained principally with the [[Dow process]], by [[electrolysis]] of fused magnesium chloride from [[brine]] and [[sea water]]. A saline solution containing Mg<sup>2+</sup> ions is first treated with [[Calcium oxide|lime]] (calcium oxide) and the precipitated [[magnesium hydroxide]] is collected:
The hydroxide is then converted to a partial [[hydrate]] of [[magnesium chloride]] by treating the hydroxide with [[hydrochloric acid]] and heating of the product:
A new process, solid oxide membrane technology, involves the electrolytic reduction of MgO. At the cathode, {{chem|Mg|2+}} ion is reduced by two [[electron]]s to magnesium metal. The electrolyte is [[Yttria-stabilized zirconia]] (YSZ). The anode is a liquid metal. At the YSZ/liquid metal anode {{chem|O|2-}} is oxidized. A layer of graphite borders the liquid metal anode, and at this interface carbon and oxygen react to form carbon monoxide. When silver is used as the liquid metal anode, there is no reductant carbon or hydrogen needed, and only oxygen gas is evolved at the anode.<ref name="The Use of Solid-Oxide-Membrane Technology for Electrometallurgy">{{cite journal|last1=Pal|first1=Uday B. |last2=Powell|first2=Adam C.|title=The Use of Solid-Oxide-Membrane Technology for Electrometallurgy|date=2007|bibcode=2007JOM....59e..44P|volume=59|page=44|journal=JOM|doi=10.1007/s11837-007-0064-x|issue=5}}</ref> It has been reported that this method provides a 40% reduction in cost per pound over the electrolytic reduction method.<ref>{{cite web| url=http://www1.eere.energy.gov/vehiclesandfuels/pdfs/merit_review_2011/lightweight_materials/lm035_derezinski_2011_o.pdf|publisher=MOxST| title=Solid Oxide Membrane (SOM) Electrolysis of Magnesium: Scale-Up Research and Engineering for Light-Weight Vehicles |first=Steve| last=Derezinski |date=12 May 2011| accessdate=27 May 2013}}</ref> This method is more environmentally sound than others because there is much less carbon dioxide emitted.
The United States has traditionally been the major world supplier of this metal, supplying 45% of world production even as recently as 1995. Today, the US market share is at 7%, with a single domestic producer left, US Magnesium, a [[Renco Group]] company in [[Utah]] born from now-defunct Magcorp.<ref>{{cite web| url=http://www.forbes.com/forbes/2002/0722/044_print.html| publisher=Forbes.com| title=Man With Many Enemies| first=Nathan| last= Vardi |date=22 February 2007|accessdate=26 June 2006}}</ref>
== History ==
== History ==
The name magnesium originates from the [[Ancient Greek|Greek]] word for a district in [[Thessaly]] called [[Magnesia (regional unit)|Magnesia]].<ref>{{cite web |url=http://www.webelements.com/magnesium/history.html |title=Magnesium: historical information |publisher=webelements.com |accessdate=9 October 2014}}</ref> It is related to [[magnetite]] and [[manganese]], which also originated from this area, and required differentiation as separate substances. See [[manganese]] for this history.
The name originates from the [[Ancient Greek|Greek]] word for a district in [[Thessaly]] called [[Magnesia]]. It is related to [[magnetite]] and [[manganese]], which also originated from this area, and required differentiation as separate substances. See [[manganese]] for this history.
In 1618, a farmer at Epsom in England attempted to give his cows water from a well there. The cows refused to drink because of the water's bitter taste, but the farmer noticed that the water seemed to heal scratches and rashes. The substance became known as [[Magnesium sulfate|Epsom salts]] and its fame spread. It was eventually recognized as hydrated magnesium sulfate, MgSO<sub>4</sub>·7{{hsp}}H<sub>2</sub>O.
Magnesium is the seventh most abundant element in the earth's crust by mass and eighth by molarity.<ref name="Abundance">{{cite paper |title=Abundance and form of the most abundant elements in Earth’s continental crust |format=PDF |accessdate=2008-02-15 |url=http://www.gly.uga.edu/railsback/Fundamentals/ElementalAbundanceTableP.pdf}}</ref> It is found in large deposits of [[magnesite]], [[dolomite]], and other [[mineral]]s, 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. 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 recognized to be hydrated magnesium sulfate, MgSO<sub>4</sub>.
The metal itself was first produced by [[Humphry Davy|Sir Humphry Davy]] in England in 1808. He used electrolysis on a mixture of magnesia and [[Mercury(II) oxide|mercuric oxide]].<ref name="Davy1808">{{cite journal| last = Davy | first = H. | date= 1808 | title = Electro-chemical researches on the decomposition of the earths; with observations on the metals obtained from the alkaline earths, and on the amalgam procured from ammonia | journal = Philosophical Transactions of the Royal Society of London | volume = 98 | pages = 333–370|bibcode = 1808RSPT...98..333D | jstor=107302 | doi=10.1098/rstl.1808.0023| url = http://books.google.com/books?id=gpwEAAAAYAAJ&pg=102#v=onepage&q&f=false}}</ref> [[Antoine Bussy]] prepared it in coherent form in 1831. Davy's first suggestion for a name was magnium,<ref name="Davy1808" /> but the name magnesium is now used.
In England, Sir [[Humphry Davy]] electrolytically isolated pure magnesium metal in 1808 from a mix of magnesia and [[mercury (element)|Hg]][[oxygen|O]], 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.
== Uses ==
== Sources ==
Although magnesium is found in over 60 [[mineral]]s, only [[dolomite]], [[magnesite]], [[brucite]], [[carnallite]], [[talc]], and [[olivine]] are of commercial importance.
=== As a metal ===
In the [[United States]] this metal is principally obtained by [[electrolysis]] of fused [[magnesium chloride]] from [[brine]]s, wells, and [[sea water]]:
[[File:Bundesarchiv Bild 102-12062, Wasserreiter mit Magnesiumfackeln.jpg|thumb|An unusual application of magnesium as an [[Illumination (lighting)|illumination]] source while [[wakeskating]] in 1931]]
[[Image:Magnesium crystals.jpg|thumb|Vapor-deposited magnesium crystals from the [[Pidgeon process]]]]
The United States has traditionally been the major world supplier of this metal, supplying 45% of world production even as recently as 1995. Today, the US market share is at 7%, with a single domestic producer left, [[US Magnesium]], a company born from now-defunct [[Magcorp]].<ref>{{cite web| url=http://www.forbes.com/forbes/2002/0722/044_print.html| publisher=Forbes.com| title=Man With Many Enemies| first=Nathan| last= Vardi |date=[[February 22]] [[2007]] | accessdate=2006-06-26}}</ref> As of 2005 [[China]] has taken over as the dominant supplier, pegged at 60% world market share, which increased from 4% in 1995. Unlike the above described [[electrolyte|electrolytic]] process, China is almost completely reliant on a different method of obtaining the metal from its ores, the [[Silicothermic reaction|silicothermic]] [[Pidgeon process]] (the reduction of the oxide at high temperatures with silicon).
Magnesium is the third-most-commonly-used structural metal, following [[iron]] and aluminium. It has been called the lightest useful metal by [[The Periodic Table of Videos]].<ref>{{cite web|url=http://www.periodicvideos.com/videos/012.htm|title = Magnesium Video – The Periodic Table of Videos – University of Nottingham|accessdate=23 February 2011}}</ref>
===Magnesium from sea water===
The Mg<sup>2+</sup> cation is the second most abundant cation in seawater (occurring at about 12% of the mass of sodium there), which makes seawater and sea-salt an attractive commercial source of Mg. To extract the magnesium, [[calcium carbonate]] is added to sea water to form [[magnesium carbonate]] precipitate.
The main applications of magnesium are, in order: component of aluminium alloys, in [[die-casting]] (alloyed with [[zinc]]),<ref name="BakerM. M. Avedesian1999">{{cite book|last1=Baker|first1=Hugh D. R.|last2=Avedesian|first2=Michael|title=Magnesium and magnesium alloys|date=1999|publisher=Materials Information Society|location=Materials Park, OH|isbn=0-87170-657-1|page=4}}</ref> to remove [[sulfur]] in the production of iron and steel, and the production of [[titanium]] in the [[Kroll process]].<ref>{{cite encyclopedia|display-authors=6|author=Ketil Amundsen|author2=Terje Kr. Aune|author3=Per Bakke|author4=Hans R. Eklund|author5=Johanna Ö. Haagensen|author6=Carlos Nicolas|author7=Christian Rosenkilde|author8=Sia Van den Bremt|author9=Oddmund Wallevik |contribution=Magnesium |work=Ullmann's Encyclopedia of Industrial Chemistry |date=2002|publisher=Wiley-VCH |doi=10.1002/14356007.a15_559|title=Ullmann's Encyclopedia of Industrial Chemistry|isbn=3527306730 }}</ref>
Historically, magnesium was one of the main aerospace construction metals and was used for German military aircraft as early as World War I and extensively for German aircraft in World War II.
[[Magnesium carbonate]] is insoluble in water so it can be filtered out, and reacted with [[hydrochloric acid]] to obtain concentrated [[magnesium chloride]].
The Germans coined the name "[[Elektron (alloy)|Elektron]]" for magnesium alloy. The term is still used today. The application of magnesium in the commercial aerospace industry was generally restricted to engine-related components, due either to perceived hazards with magnesium parts in the event of fire or to corrosion. Currently, the use of magnesium alloys in aerospace is increasing, mostly driven by the increasing importance of fuel economy and the need to reduce weight.<ref>{{cite journal |doi= 10.4028/www.scientific.net/MSF.350-351.19 |title= Magnesium Alloys Development towards the 21st Century |date= 2000 |last1= Aghion |first1= E. |last2= Bronfin |first2= B. |journal= Materials Science Forum |volume= 350–351 |pages= 19}}</ref> The development and testing of new magnesium alloys continues, notably Elektron 21, which has successfully undergone extensive aerospace testing for suitability in engine and internal and airframe components.<ref>{{cite book|last1=Bronfin|first1=B|last2=et al.|editor=Kainer, Karl|title=Magnesium: Proceedings of the 7th International Conference on Magnesium Alloys and Their Applications|date=2007|publisher=Wiley|location=Weinheim, Germany|isbn=978-3-527-31764-6|page=23|chapter=Elektron 21 specification}}</ref> The European Community runs three R&D magnesium projects in the Aerospace priority of Six Framework Program.
From [[magnesium chloride]], electrolysis produces magnesium.
* [[Wright Aeronautical]] used a magnesium crankcase in the WWII-era [[Wright R-3350|Wright Duplex Cyclone]] aviation engine. This presented a serious problem for the earliest examples of the [[Boeing B-29]] heavy bomber, as engine fires in flight could ignite the engine crankcases, literally "torching" the wing spar apart.<ref>{{cite book | url = http://books.google.com/books?id=EBmynsBj2BUC&pg=PA40| pages=40–41 | title = Mission to Tokyo: The American Airmen Who Took the War to the Heart of Japan | isbn = 9781610586634 | author1 = Dorr | first1 = Robert F | date = 15 September 2012}}</ref><ref>{{cite book |url=http://books.google.com/?id=JEwpAQAAIAAJ | title=AAHS Journal |volume=44–45 | date=1999 |publisher=American Aviation Historical Society }}</ref>
====Automotive====
{{seealso|Category:Magnesium minerals}}
[[File:Mg alloy car engine blocks.jpg|thumb|Mg alloy car engine blocks]]
* [[Mercedes-Benz]] used the alloy [[Elektron (alloy)|Elektron]] in the body of an early model [[Mercedes-Benz 300 SLR]]; these cars ran (with successes) at [[24 Hours of Le Mans|Le Mans]], the [[Mille Miglia]], and other world-class race events in 1955.
* [[Porsche]] used magnesium alloy frames in the [[Porsche 917|917/053]] that won Le Mans in 1971, and continues to use magnesium alloys for its [[engine block]]s due to the weight advantage.
* [[Volkswagen Group]] has used magnesium in its engine components for many years.{{citation needed|date=May 2014}}
* [[Mitsubishi Motors]] also uses magnesium for its paddle shifters.
* [[BMW]] used magnesium alloy engine blocks in the 2006 325i and 330i models, including an aluminium alloy insert for the cylinder walls and cooling jackets surrounded by a high-temperature magnesium alloy AJ62A.
* [[Chevrolet]] used the magnesium alloy AE44 in the 2006 Corvette [[Corvette C6|Z06]].
Both AJ62A and AE44 are recent developments in high-temperature low-[[Creep (deformation)|creep]] magnesium alloys. The general strategy for such alloys is to form [[intermetallic]] precipitates at the [[crystallite|grain boundaries]], for example by adding [[mischmetal]] or [[calcium]].<ref>{{cite journal |title=Tensile and Compressive Creep of Magnesium-Aluminum-Calcium Based Alloys |format=PDF |date=2001 |author=Luo, Alan A. |author2=Powell, Bob R. |last-author-amp=yes |publisher=Materials & Processes Laboratory, General Motors Research & Development Center |accessdate=21 August 2007 |url=http://doc.tms.org/ezmerchant/prodtms.nsf/productlookupitemid/01-481x-137/%24FILE/01-481X-137F.pdf |archiveurl=http://web.archive.org/web/20070928023445/http://doc.tms.org/ezmerchant/prodtms.nsf/productlookupitemid/01-481x-137/$FILE/01-481X-137F.pdf |archivedate=28 September 2007 }}</ref> New alloy development and lower costs that make magnesium competitive with aluminium will increase the number of automotive applications.
====Electronics====
== Biology ==
Because of low weight and good mechanical and electrical properties, magnesium is widely used for manufacturing of mobile phones, laptop and [[tablet computers]], cameras, and other electronic components.
{{main|Magnesium in biology}}
[[File:Magnesium-products.jpg|thumb|left|Products made of magnesium: firestarter and shavings, sharpener, magnesium ribbon]]
Magnesium ions are essential to the basic [[nucleic acid]] chemistry of life, and thus are essential to all cells of all known living organisms. [[Plants]] have an additional use for magnesium in that [[chlorophyll]]s are magnesium-centered [[porphyrin]]s. Many [[enzyme]]s require the presence of magnesium ions for their catalytic action, especially enzymes utilizing [[Adenosine triphosphate|ATP]], or those which use other nucleotides to synthesize [[DNA]] and [[RNA]]. [[Magnesium deficiency]] in plants causes late-season yellowing between leaf veins, especially in older leaves, and can be corrected by applying epsom salts (which is rapidly [[leaching|leached]]), or else crushed [[dolomite|dolomitic]] [[limestone]] to the soil.
[[Image:FoodSourcesOfMagnesium.jpg|thumb|right|Food sources of magnesium]]
Magnesium is a vital component of a healthy human diet and deficiency has been implicated in a number of human diseases. Magnesium is readily available in many common foods but studies indicate that many Americans are magnesium deficient. Excess magnesium in the blood is freely filtered at the kidneys, and for this reason it is very difficult to overdose on magnesium from dietary sources alone.<ref>[http://www.umm.edu/altmed/articles/magnesium-000313.htm Magnesium<!-- Bot generated title -->]</ref> However, there are a number of magnesium supplements available which make overdose possible, particularly in people with poor renal function, but severe [[hypermagnesemia]] can also occur without renal dysfunction.<ref>{{cite journal |author=Kontani M, Hara A, Ohta S, Ikeda T |title=Hypermagnesemia induced by massive cathartic ingestion in an elderly woman without pre-existing renal dysfunction |journal=Intern. Med. |volume=44 |issue=5 |pages=448–52 |year=2005 |pmid=15942092 |doi= | doi = 10.2169/internalmedicine.44.448 <!--Retrieved from CrossRef by DOI bot-->}}</ref>
==== Niche uses of the metal ====
== Isotopes ==
Magnesium, being readily available and relatively nontoxic, has a variety of uses:
Magnesium has three stable [[isotope]]s: <sup>24</sup>Mg, <sup>25</sup>Mg, <sup>26</sup>Mg. All are present in significant amounts (see table of isotopes above). About 79% of Mg is <sup>24</sup>Mg. The isotope <sup>28</sup>Mg is radioactive and in the 1950s to 1970s was made commercially by several nuclear power plants for use in scientific experiments. This isotope has a relatively short half-life (21 hours) and so its use was limited by shipping times.
* Magnesium is flammable, burning at a temperature of approximately {{convert|3100|°C|K °F|abbr=on}},<ref name="Dreizin, Edward L.; Berman, Charles H. and Vicenzi, Edward P. 2000 30" /> and the [[autoignition temperature]] of magnesium ribbon is approximately {{convert|473|°C|K °F|abbr=on}}.<ref>{{cite web
| title = Magnesium (Powder)
| work = International Programme on Chemical Safety (IPCS)
}}</ref> It produces intense, bright, white light when it burns. Magnesium's high combustion temperature makes it a useful tool for starting emergency fires. Other uses include flash [[photography]], flares, [[pyrotechnics]], and fireworks sparklers. Magnesium is also often used to ignite thermite or other materials that require a high ignition temperature.[[File:Magnesium Sparks.jpg|thumb|Magnesium firestarter (in left hand), used with a [[pocket knife]] and flint to create sparks that ignite the shavings]]
* In the form of turnings or ribbons, to prepare [[Grignard reagent]]s, which are useful in [[organic synthesis]].
* As an additive agent in conventional propellants and the production of [[Ductile iron|nodular graphite in cast iron]].
* As a reducing agent to separate [[uranium]] and other metals from their [[salt]]s.
* As a [[Sacrificial anode|sacrificial (galvanic) anode]] to protect underground tanks, pipelines, buried structures, and water heaters.
* Alloyed with zinc to produce the zinc sheet used in [[photoengraving]] plates in the printing industry, [[Dry cell|dry-cell battery]] walls, and [[Flashing (weatherproofing)|roofing]].<ref name="BakerM. M. Avedesian1999" />
* 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 can]]s, sports equipment such as golf clubs, fishing reels, and archery bows and arrows.
* Specialty, high-grade car wheels of magnesium alloy are called "[[Magnesium alloy wheel|mag wheels]]", although the term is often more broadly misapplied to include aluminium wheels. Many car and aircraft manufacturers have made engine and body parts from magnesium.
=== In compounds ===
<sup>26</sup>Mg has found application in [[isotope|isotopic]] [[geology]], similar to that of [[aluminium]]. <sup>26</sup>Mg is a [[radiogenic]] daughter product of <sup>26</sup>Al, which has a [[half-life]] of 717,000 years. Large enrichments of stable <sup>26</sup>Mg have been observed in the [[Ca-Al-rich inclusions]] of some [[carbonaceous chondrite]] [[meteorite]]s. The anomalous abundance of <sup>26</sup>Mg is attributed to the decay of its parent <sup>26</sup>Al in the inclusions. Therefore, the meteorite must have formed in the [[solar nebula]] before the <sup>26</sup>Al had decayed. Hence, these fragments are among the oldest objects in the [[solar system]] and have preserved information about its early history.
Magnesium compounds, primarily [[magnesium oxide]] (MgO), are used as a [[refractory]] material in [[furnace]] linings for producing [[iron]], [[steel]], [[nonferrous metal]]s, [[glass]], and [[cement]]. Magnesium oxide and other magnesium compounds are also used in the agricultural, chemical, and construction industries. Magnesium oxide from [[calcination]] is used as an electrical insulator in [[Mineral-insulated copper-clad cable|fire-resistant cables]].<ref>{{cite book|last=Linsley|first=Trevor|title=Basic Electrical Installation Work|isbn=978-0-08-096628-1|page=362|date=2011|chapter=Properties of conductors and insulators}}</ref>
Magnesium reacted with an [[alkyl halide]] gives a [[Grignard reaction|Grignard reagent]], which is a very useful tool for preparing [[alcohols]].
It is conventional to plot <sup>26</sup>Mg/<sup>24</sup>Mg against an Al/Mg ratio. In an [[isochron dating]] plot, the Al/Mg ratio plotted is<sup>27</sup>Al/<sup>24</sup>Mg. The slope of the isochron has no age significance, but indicates the initial <sup>26</sup>Al/<sup>27</sup>Al ratio in the sample at the time when the systems were separated from a common reservoir.
Magnesium salts are frequently included in various [[food]]s, [[fertilizer]]s (magnesium is a component of [[chlorophyll]]), and [[culture medium|culture media]].
[[Magnesium sulfite]] is used in the manufacture of [[paper]] ([[sulfite process]]).
[[Magnesium phosphate]] is used to fireproof wood used in construction.
Magnesium hexafluorosilicate is used in mothproofing of [[textile]]s.
In the form of turnings or ribbons, Mg is useful in [[Solvent#Desiccant|purification of solvents]], for example the preparation of super-dry ethanol.
==== Biological ====
[[Magnesium (pharmaceutical preparation)|Pharmaceutical preparations of magnesium]] are used to treat [[magnesium deficiency (medicine)|magnesium deficiency]] and [[hypomagnesemia]], as well as [[eclampsia]].<ref name=Euser2009>{{cite doi|10.1161/STROKEAHA.108.527788}}</ref> Usually in lower dosages, magnesium is commonly included in [[dietary mineral]] preparations, including many [[multivitamin]] preparations.
Sorted by type of magnesium salt, biological applications of magnesium include:
* [[Magnesium sulfate]], as the [[hydrate|heptahydrate]] called Epsom salts, is used as [[bath salts]], as a [[laxative]], and as a highly soluble [[fertilizer]].<ref>{{cite book | url = http://books.google.com/books?id=GP1caeWDUWkC&pg=PA224 | page=224 | title = The Fertilizer Encyclopedia | isbn = 9780470431764 | last1 = Gowariker | first1 = Vasant | last2 = Krishnamurthy |first2=V.P. |first3=Sudha |last3=Gowariker |first4=Manik |last4=Dhanorkar |first5=Kalyani |last5=Paranjape | date = 8 April 2009}}</ref>
* [[Magnesium hydroxide]], suspended in water, is used in [[milk of magnesia]] [[antacid]]s and [[laxative]]s.
* [[Magnesium chloride]], [[magnesium oxide|oxide]], [[magnesium gluconate|gluconate]], [[magnesium malate|malate]], [[magnesium orotate|orotate]], glycinate and [[magnesium citrate|citrate]] are all used as oral magnesium supplements. Some have claimed that oral magnesium supplements are therapeutic for [[restless leg syndrome]] (RLS) in some individuals.<ref>{{cite web|url=http://www.med.nyu.edu/content?ChunkIID=21806 |title=NYU Langone Medical Center |publisher=Med.nyu.edu |accessdate=19 September 2013}}</ref>
* [[Borate|Magnesium borate]], [[magnesium salicylate]], and [[magnesium sulfate]] are used as [[antiseptic]]s.
* [[Magnesium bromide]] is used as a mild [[sedative]] (this action is due to the [[bromide]], not the magnesium).
* [[Magnesium stearate]] is a slightly [[fire|flammable]] white [[Powder (substance)|powder]] with [[lubricant|lubricating]] properties. In [[pharmacology|pharmaceutical]] technology, it is used in the manufacturing of numerous kinds of [[Tablet (pharmacy)|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).
* Magnesium carbonate powder is used by athletes such as [[gymnastics|gymnasts]], [[Olympic weightlifting|weightlifters]], and [[climbing|climbers]] to eliminate moisture and improving the grip on a gymnastic apparatus, lifting bar, and climbing rocks.
* Magnesium <small>L</small>-threonate is used a dietary magnesium supplement
== Biological roles ==
{{Main|Magnesium in biology}}
===Mechanism of action===
Because of the important interaction between [[phosphate]] and magnesium ions, magnesium ions are essential to the basic [[nucleic acid]] chemistry of life, and thus are essential to all cells of all known living organisms. Over 300 [[enzyme]]s require the presence of magnesium ions for their catalytic action, including all enzymes utilizing or synthesizing [[Adenosine triphosphate|ATP]], or those that use other [[nucleotides]] to synthesize [[DNA]] and [[RNA]]. ATP exists in cells normally as a [[Chelation|chelate]] of ATP and a magnesium ion.<ref>
{{cite book
| first1=Andrea, M.P.
| last1=Romani
|editor=Astrid Sigel
|editor2=Helmut Sigel
|editor3=Roland K. O. Sigel
|title=Interrelations between Essential Metal Ions and Human Diseases
|series=Metal Ions in Life Sciences
|volume=13
|date=2013
|publisher=Springer
|pages=49–79
|chapter=Chapter 3. Magnesium in Health and Disease
|doi=10.1007/978-94-007-7500-8_3
}}
</ref>
===Dietary sources, recommended intake, and supplementation===
== Precautions ==
[[File:FoodSourcesOfMagnesium.jpg|thumb|upright|alt=refer to caption; follow link for complete description|Examples of food sources of magnesium]] Spices, nuts, cereals, cocoa and vegetables are rich sources of magnesium.<ref>{{cite web|url = http://ods.od.nih.gov/factsheets/magnesium/|title = Dietary Supplement Fact Sheet: Magnesium| publisher = Office of Dietary Supplements}}</ref> Green leafy vegetables such as [[spinach]] are also rich in magnesium since they contain chlorophyll.
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. Magnesium powder is an explosive hazard. One should wear safety glasses while working with magnesium, and if burning it, these should include a heavy U.V. filter, similar to welding eye protection. The bright white light (including [[ultraviolet]]) produced by burning magnesium can permanently damage the retinas of the eyes, similar to welding arc burns.<ref>{{cite web |url=http://www.edu.gov.mb.ca/k12/docs/support/scisafe/chapter8.html |title=Science Safety: Chapter 8 |publisher=Government of Manitoba |accessdate=2007-08-21}}</ref>
The UK recommended daily values for magnesium is 300 mg for men and 270 mg for women.<ref>{{cite web|url=http://www.nhs.uk/Conditions/vitamins-minerals/Pages/Other-vitamins-minerals.aspx |title=Vitamins and minerals – Others – NHS Choices |publisher=Nhs.uk |date=26 November 2012 |accessdate=19 September 2013}}</ref> Observations of reduced dietary magnesium intake in modern Western countries compared to earlier generations may be related to food refining and modern fertilizers that contain no magnesium.<ref name=Wester1987 />
Water should not be used to extinguish magnesium fires, because it can produce hydrogen which will feed the fire, according to the reaction:<ref>{{cite web| url=http://www.webelements.com/webelements/elements/text/Mg/chem.html| title=Chemistry : Periodic Table : magnesium : chemical reaction data| accessdate=2006-06-26| publisher=webelements.com}}</ref>
Numerous [[Magnesium (pharmaceutical preparation)|pharmaceutical preparations of magnesium]], as well as magnesium [[dietary supplement]]s are available. [[Magnesium oxide]], one of the most common forms in magnesium dietary supplements because it has high magnesium content per weight, has been reported the least [[Bioavailability|bioavailable]].<ref name=Firoz2001>{{cite journal |author=Firoz M|author2=Graber M |title=Bioavailability of US commercial magnesium preparations |journal=Magnes Res |volume=14 |issue=4 |pages=257–62 |date=2001 |pmid=11794633}}</ref><ref name=Lindberg1990>{{cite journal |author=Lindberg JS|author2=Zobitz MM|author3=Poindexter JR|author4=Pak CY |title=Magnesium bioavailability from magnesium citrate and magnesium oxide |journal=J Am Coll Nutr |volume=9 |issue=1 |pages=48–55 |date=1990|pmid=2407766 |doi=10.1080/07315724.1990.10720349}}</ref>
Carbon dioxide [[fire extinguisher]]s should not be used either, because magnesium can burn in carbon dioxide (forming [[magnesium oxide]], MgO, and [[carbon]]).<ref>{{cite web| url=http://www.ilpi.com/genchem/demo/co2mg/| title=Demo Lab: Reaction Of Magnesium Metal With Carbon Dioxide| accessdate=2006-06-26}}</ref> A [[Class D Fire Extinguisher|Class D]] dry chemical fire extinguisher should be used if available, or else the fire should be covered with [[sand]] or magnesium foundry flux. An easy way to put out small metal fires is to place a polyethylene bag filled with dry sand on top of the fire. The heat of the fire will melt the bag and the sand will flow out onto the fire.
There is limited evidence that magnesium supplementation may play a role in the prevention and treatment of [[migraine]].<ref name=migraine>{{vcite2 journal |vauthors=Teigen L, Boes CJ |title=An evidence-based review of oral magnesium supplementation in the preventive treatment of migraine |journal=Cephalalgia |volume= |issue= |pages= |year=2014 |pmid=25533715 |doi=10.1177/0333102414564891 |type=Review |quote=There is a strong body of evidence demonstrating a relationship between magnesium status and migraine. Magnesium likely plays a role in migraine development at a biochemical level, but the role of oral magnesium supplementation in migraine prophylaxis and treatment remains to be fully elucidated. The strength of evidence supporting oral magnesium supplementation is limited at this time. }}</ref>
===Metabolism===
An adult has 22-26 grams of magnesium,<ref>PMID 10727669</ref> with 60% in the [[skeleton]], 39% intracellular (20% in skeletal muscle), and 1% extracellular.<ref>{{cite web|title=Dietary Supplement Fact Sheet:Magnesium|url=http://ods.od.nih.gov/factsheets/Magnesium-HealthProfessional/|publisher=US National Institute of Health}}</ref> Serum levels are typically 0.7–1.0 mmol/L or 1.8–2.4 mEq/L. Serum magnesium levels may be normal even when intracellular magnesium is deficient. The mechanisms for maintaining the magnesium level in the serum are varying gastrointestinal absorption and renal excretion. Intracellular magnesium is correlated with intracellular [[potassium]]. Increased magnesium lowers [[calcium]]<ref name=ummedu>{{cite web|url=http://umm.edu/health/medical/altmed/supplement/magnesium |title=Magnesium | University of Maryland Medical Center |publisher=Umm.edu |date=7 May 2013 |accessdate=19 September 2013}}</ref> and can either prevent hypercalcemia or cause hypocalcemia depending on the initial level.<ref name=ummedu /> Low and high protein intake inhibit magnesium absorption, as does the amount of [[phosphate]], [[phytate]], and [[fat]] in the gut. Excess dietary magnesium is excreted in feces, urine, and sweat.<ref name=Wester1987>{{cite journal |author=Wester PO |title=Magnesium |journal=Am. J. Clin. Nutr. |volume=45 |issue=5 Suppl |pages=1305–12 |date=1987 |pmid=3578120}}</ref> Magnesium status may be assessed via serum and erythrocyte magnesium concentrations coupled with urinary and fecal magnesium content, but intravenous magnesium loading tests are more accurate and practical.<ref>{{cite journal |author=Arnaud MJ |title=Update on the assessment of magnesium status |journal=Br. J. Nutr. |volume=99 Suppl 3 |pages=S24–36 |date=2008|pmid=18598586 |doi=10.1017/S000711450800682X }}</ref> A retention of 20% or more of the injected amount indicates deficiency.<ref>{{cite journal |display-authors=6|author=Rob PM|author2=Dick K|author3=Bley N|author4=Seyfert T|author5=Brinckmann C|author6=Höllriegel V|author7=Friedrich HJ|author8=Dibbelt L|author9=Seelig MS|title=Can one really measure magnesium deficiency using the short-term magnesium loading test? |journal=J. Intern. Med. |volume=246 |issue=4 |pages=373–378 |date=1999 |pmid=10583708 |doi= 10.1046/j.1365-2796.1999.00580.x }}</ref> No biomarker has been established for magnesium.<ref>{{cite journal |author=Franz KB |title=A functional biological marker is needed for diagnosing magnesium deficiency |journal=J Am Coll Nutr |volume=23 |issue=6 |pages=738S–41S |date=2004|pmid=15637224 |doi=10.1080/07315724.2004.10719418}}</ref>
=== Detection in serum and plasma ===
Magnesium concentrations in plasma or serum may be measured to monitor for efficacy and safety in those receiving the drug therapeutically, to confirm the diagnosis in potential poisoning victims or to assist in the forensic investigation in a case of fatal overdosage. The newborn children of mothers having received parenteral magnesium sulfate during labor may exhibit toxicity with normal serum magnesium levels.<ref>Baselt, R. (2008) ''Disposition of Toxic Drugs and Chemicals in Man'', 8th edition, Biomedical Publications, Foster City, CA, ISBN 0-9626523-7-7, pp. 875–877.</ref>
===Deficiency===
Magnesium deficiency (hypomagnesemia) is common: it is found in 2.5 - 15% of the general population.<ref name= Ayuk>Ayuk, J.; Gittoes. N.J. "Contemporary view of the clinical relevance of magnesium homeostasis" Ann. Clin. Biochem. 2014 Mar;51(Pt 2):179-88. {{doi| 10.1177/0004563213517628}}</ref> The primary cause of deficiency is decreased dietary intake: only 32% of people in the United States meet the recommended daily allowance.<ref>{{cite web|url = http://www.ars.usda.gov/is/AR/archive/may04/energy0504.htm?pf=1|title = Lack Energy? Maybe It's Your Magnesium Level|publisher = United States Department of Agriculture|accessdate = 18 September 2008}} Last paragraph</ref> Other causes are increased renal or gastrointestinal loss, an increased intracellular shift, and proton-pump inhibitor antacid therapy. Most are asymptomatic, but symptoms referable to neuromuscular, cardiovascular, and metabolic dysfunction may occur.<ref name= Ayuk/> Alcoholism is often associated with magnesium deficiency. Chronically low serum magnesium levels are associated with [[metabolic syndrome]], [[diabetes mellitus type 2]] and [[hypertension]].<ref name= Geiger2012>{{cite journal |author= Geiger H|author2= Wanner C |title= Magnesium in disease |journal= Clin Kidney J |volume=5 |issue= Suppl 1 |pages= i25–i38 |date=2012|doi= 10.1093/ndtplus/sfr165|url= http://ckj.oxfordjournals.org/content/5/Suppl_1/i25.full.pdf}}</ref>
===Therapy===
*Intravenous magnesium is recommended by the ACC/AHA/ESC 2006 Guidelines for Management of Patients With Ventricular Arrhythmias and the Prevention of Sudden Cardiac Death for patients with ventricular [[arrhythmia]] associated with [[torsades de pointes]] who present with [[long QT syndrome]]; and for the treatment of patients with digoxin induced arrhythmias.<ref name= Zipes2006>{{cite journal |author= Zipes DP|author2= Camm AJ|author3= Borggrefe M|author4= et al. |title= ACC/AHA/ESC 2006 Guidelines for Management of Patients With Ventricular Arrhythmias and the Prevention of Sudden Cardiac Death: a report of the American College of Cardiology/American Heart Association Task Force and the European Society of Cardiology Committee for Practice Guidelines (writing committee to develop Guidelines for Management of Patients With Ventricular Arrhythmias and the Prevention of Sudden Cardiac Death): developed in collaboration with the European Heart Rhythm Association and the Heart Rhythm Society |journal= Circulation |volume=114 |pages= e385–e484|date=2012 |doi= 10.1161/CIRCULATIONAHA.106.178233 |pmid= 16935995 |url= http://circ.ahajournals.org/content/114/10/e385.full.pdf |issue= 10 }}</ref>
*Magnesium is the drug of choice in the management of [[pre-eclampsia]] and [[eclampsia]].<ref name= James2010>{{cite journal |author= James MF |title= Magnesium in obstetrics |journal= Best Pract Res Clin Obstet Gynaecol |volume=24 |pages=327–337|date=2010 |doi=10.1016/j.bpobgyn.2009.11.004 |pmid= 20005782 |issue= 3}}</ref>
*Hypomagnesemia, including that caused by alcoholism, is reversible by oral or parenteral magnesium administration depending on the degree of deficiency.<ref>{{cite book|author=Giannini, A. J.|title=Drugs of Abuse|edition=Second|location=Los Angeles|publisher=Physicians Management Information Co.|date=1997|isbn=0-87489-499-9}}</ref>
===Overdose===
Overdose from dietary sources alone is unlikely because excess magnesium in the blood is promptly filtered by the kidneys.<ref name= Ayuk/> Overdose with magnesium tablets is possible in the presence of impaired renal function. There is a single case report of [[hypermagnesemia]] in a woman with normal renal function using high doses of magnesium salts for catharsis.<ref name="Kontani M, Hara A, Ohta S, Ikeda T 2005 448–452">{{cite journal |author=Kontani M|author2=Hara A|author3=Ohta S|author4= Ikeda T |title=Hypermagnesemia induced by massive cathartic ingestion in an elderly woman without pre-existing renal dysfunction |journal=Intern. Med. |volume=44 |issue=5 |pages=448–452 |date=2005 |pmid=15942092| doi = 10.2169/internalmedicine.44.448}}</ref> The most common symptoms of overdose are nausea, vomiting and diarrhea; other symptoms include hypotension, confusion, slowed heart and respiratory rate, deficiencies of other minerals, coma, cardiac arrhythmia, and death from cardiac arrest.<ref name=ummedu />
===Function in plants===
[[Plants]] require magnesium to synthesize [[chlorophyll]]. Magnesium in the center of the [[porphyrin ring]] in chlorophyll functions in a manner similar to the iron in the center of the porphyrin ring in [[heme]]. [[Magnesium deficiency (plants)|Magnesium deficiency]] in plants causes late-season yellowing between leaf veins, especially in older leaves, and can be corrected by applying to the soil either [[Epsom salts]] (which is rapidly [[Leaching (chemical science)|leached]]), or crushed [[dolomite|dolomitic]] [[limestone]].
== Safety precautions for the metal ==
[[File:Schlesser.jpg|thumb|right|The combusting magnesium-bodied [[Honda RA302]] at the [[1968 French Grand Prix]], after the crash that killed driver [[Jo Schlesser]].]]
Magnesium metal and its alloys are explosive hazards; they are highly flammable in their pure form when molten or in powder or ribbon form. Burning or molten magnesium metal reacts violently with water. When working with powdered magnesium, [[safety glasses]] with welding [[eye protection]] are employed, because the bright-white light produced by burning magnesium contains [[ultraviolet]] light that can permanently damage the [[retina]]s of the eyes.<ref>{{cite web |url=http://www.edu.gov.mb.ca/k12/docs/support/scisafe/chapter8.html |title=Science Safety: Chapter 8 |publisher=Government of Manitoba |accessdate=21 August 2007}}</ref>
Magnesium is capable of reducing [[water (molecule)|water]] to highly flammable [[hydrogen]] gas:<ref>{{cite web| url=http://www.webelements.com/webelements/elements/text/Mg/chem.html| title=Chemistry : Periodic Table : magnesium : chemical reaction data| accessdate=26 June 2006| publisher=webelements.com}}</ref>
:Mg (s) + 2 {{chem|H|2|O}} (l) → [[Magnesium hydroxide|{{chem|Mg(OH)|2}}]] (s) + {{chem|H|2}} (g)
As a result, water cannot extinguish magnesium fires. The hydrogen gas produced only intensifies the fire. Dry sand is an effective smothering agent, but only on relatively level and flat surfaces.
Magnesium also reacts with [[carbon dioxide]] to form magnesium oxide and [[carbon]]:
:2 Mg + {{chem|CO|2}} → 2 MgO + C (s)
hence, carbon dioxide fire extinguishers are also ineffective for extinguishing magnesium fires.<ref>{{cite web| url=http://www.ilpi.com/genchem/demo/co2mg/| title=Demo Lab: Reaction Of Magnesium Metal With Carbon Dioxide| accessdate=26 June 2006}}</ref>
Burning magnesium is usually quenched by using a [[Fire extinguisher#Class D|Class D]] dry chemical fire extinguisher, or by covering the fire with [[sand]] or magnesium foundry flux to remove its air source.
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==Notes==
== References ==
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== References ==
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== External links ==
* [http://www.periodicvideos.com/videos/012.htm Magnesium] at ''[[The Periodic Table of Videos]]'' (University of Nottingham)
* [http://www.rsc.org/chemistryworld/podcast/element.asp Chemistry in its element podcast] (MP3) from the [[Royal Society of Chemistry]]'s [[Chemistry World]]: [http://www.rsc.org/images/CIIE_Magnesium_48kbps_tcm18-128524.mp3 Magnesium]
* [http://ckj.oxfordjournals.org/content/5/Suppl_1.toc Magnesium – a versatile and often overlooked element: new perspectives with a focus on chronic kidney disease]
Magnesium (Template:PronEng) is a chemical element with the symbol Mg, the atomic number 12, and an atomic mass of 24.31. Magnesium is the ninth most abundant element in the universe by mass. It constitutes about 2% of the Earth's crust by mass,[1] and it is the third most abundant element dissolved in seawater. Magnesium ions are essential to all living cells, and is the 11th most abundant element by mass in the human body. The free element (metal) is not found in nature. Once produced from magnesium salts, this alkaline earth metal is used as an alloying agent to make aluminium-magnesium alloys, sometimes called "magnalium" or "magnelium".
Notable characteristics
Elemental magnesium is a fairly strong, silvery-white, light-weight metal (two thirds the density of aluminium). It tarnishes slightly when exposed to air, although unlike the alkaline metals, storage in an oxygen free environment is unnecessary because magnesium is protected by a thin layer of oxide which is fairly impermeable and hard to remove. Like its lower periodic table group neighbor calcium, magnesium reacts with water at room temperature, though it reacts much more slowly than calcium. When it is submerged in water, hydrogen bubbles will almost unnoticeably begin to form on the surface of the metal, though if powdered it will react much more rapidly. Magnesium also reacts with hydrochloric acid (HCl) and produces heat and hydrogen when added to it. The magnesium will begin to bubble and become hot – too hot to touch comfortably. The reaction will occur faster with higher temperatures (see precautions).
Magnesium is a highly flammable metal, but while it is easy to ignite when powdered or shaved into thin strips, it is difficult to ignite in mass or bulk. 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). When it burns in air, Magnesium produces a brilliant white light. Thus magnesium powder (flash powder) was used as a source of illumination in the early days of photography. Later, magnesium ribbon was used in electrically ignited flash bulbs. Magnesium powder is used in the manufacture of fireworks and marine flares where a brilliant white light is required.
Magnesium compounds are typically white crystals. Most are soluble in water, providing the sour-tasting magnesium ion Mg2+. Small amounts of dissolved magnesium ion contributes to the tartness and taste of natural waters. Magnesium ion in large amounts is an ionic laxative, and magnesium sulfate (Epsom salts) is sometimes used for this purpose. So-called "milk of magnesia" is a water suspension of one of the few insoluble magnesium compounds: magnesium hydroxide. The undissolved particles give rise to its appearance and name. Milk of magnesia is a mild base and is commonly used as an antacid.
Applications
As the metal
Magnesium is the third most commonly used structural metal, following steel and aluminium.
Magnesium compounds, primarily magnesium oxide, are used mainly as refractory material in furnace linings for producing iron, steel, nonferrous metals, glass and cement. 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, in its purest form, can be compared with aluminium, and is strong and light, so it is used in several high volume part manufacturing applications, including automotive and truck components. Specialty, high-grade car wheels of magnesium alloy are called "mag wheels". In 1957 a Corvette SS, designed for racing, was constructed with magnesium body panels. Porsche's all-out quest to decrease the weight of their racecars led to the use of magnesium frames in the famous 917/053 which won Le Mans in 1971, and still holds the absolute distance record. The 917/30 Can-Am car also featured a magnesium spaceframe, helping it to make the most of its prodigious 1100-1500hp. Volkswagen has used magnesium in its engine components for many years. For a long time, Porsche used magnesium alloy for its engine blocks due to the weight advantage. There is renewed interest in magnesium engine blocks, as featured in the 2006 BMW 325i and 330i models. The BMW engine uses an aluminium alloy insert for the cylinder walls and cooling jackets surrounded by a high temperature magnesium alloy AJ62A. The application of magnesium AE44 alloy in the 2006 Corvette Z06 engine cradle has advanced the technology of designing robust automotive parts in magnesium. Both of these alloys are recent developments in high temperature low creep magnesium alloys. The general strategy for such alloys is to form intermetallic precipitates at the grain boundaries, for example by adding mischmetal or calcium.[2] New alloy development and lower costs, which are becoming competitive to aluminium, will further the number of automotive applications.
Products made of magnesium: firestarter and shavings, sharpener, magnesium ribbon
The second application field of magnesium is electronic devices. Due to low weight, good mechanical and electrical properties, magnesium is widely used for manufacturing of mobile phones, laptop computers, cameras, and other electronic components. Magnesium is even used to make some higher end yo-yos, such as the Duncan Freehand Mg.
Historically, magnesium was one of the main aerospace construction metals and was used for German military aircraft as early as World War I and extensively for German aircraft in World War II. The Germans coined the name 'Elektron' for magnesium alloy which is still used today. Due to perceived hazards with magnesium parts in the event of fire, the application of magnesium in the commercial aerospace industry was generally restricted to engine related components. Currently the use of magnesium alloys in aerospace is increasing, mostly driven by the increasing importance of fuel economy and the need to reduce weight. The development and testing of new magnesium alloys notably Elektron 21 which has successfully undergone extensive aerospace testing for suitability in both engine, internal and airframe components. European Community runs three R&D magnesium projects in Aerospace priority of Six Framework Program.
Magnesium firestarter (in left hand), used with a pocket knife and flint to create sparks which ignite the shavings
Incendiary use: Magnesium is flammable, burning at a temperature of approximately 2500 K (2200 °C, 4000 °F), and the autoignition temperature of magnesium is approximately 744 K (473 °C, 883 °F) in air. The extremely high temperature at which magnesium burns makes it a handy tool for starting emergency fires during outdoor recreation. Other related uses include flashlight photography, flares, pyrotechnics, fireworks sparklers, and incendiary bombs.
Easily reacting with water, it can serve as a desiccant
In magnesium compounds
The magnesium ion is necessary for all life (see magnesium in biological systems), so magnesium salts are an additive for foods, fertilizers (Mg is a component of chlorophyll), and culture media.
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).
Magnesium phosphate is used to fireproof wood for construction.
Magnesium hexafluorosilicate is used in mothproofing of textiles.
History
The name originates from the Greek word for a district in Thessaly called Magnesia. It is related to magnetite and manganese, which also originated from this area, and required differentiation as separate substances. See manganese for this history.
Magnesium is the seventh most abundant element in the earth's crust by mass and eighth by molarity.[1] 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. 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 recognized to be hydrated magnesium sulfate, MgSO4.
In England, 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.
The United States has traditionally been the major world supplier of this metal, supplying 45% of world production even as recently as 1995. Today, the US market share is at 7%, with a single domestic producer left, US Magnesium, a company born from now-defunct Magcorp.[3] As of 2005 China has taken over as the dominant supplier, pegged at 60% world market share, which increased from 4% in 1995. Unlike the above described electrolytic process, China is almost completely reliant on a different method of obtaining the metal from its ores, the silicothermicPidgeon process (the reduction of the oxide at high temperatures with silicon).
Magnesium from sea water
The Mg2+ cation is the second most abundant cation in seawater (occurring at about 12% of the mass of sodium there), which makes seawater and sea-salt an attractive commercial source of Mg. To extract the magnesium, calcium carbonate is added to sea water to form magnesium carbonate precipitate.
Magnesium ions are essential to the basic nucleic acid chemistry of life, and thus are essential to all cells of all known living organisms. Plants have an additional use for magnesium in that chlorophylls are magnesium-centered porphyrins. Many enzymes require the presence of magnesium ions for their catalytic action, especially enzymes utilizing ATP, or those which use other nucleotides to synthesize DNA and RNA. Magnesium deficiency in plants causes late-season yellowing between leaf veins, especially in older leaves, and can be corrected by applying epsom salts (which is rapidly leached), or else crushed dolomiticlimestone to the soil.
Food sources of magnesium
Magnesium is a vital component of a healthy human diet and deficiency has been implicated in a number of human diseases. Magnesium is readily available in many common foods but studies indicate that many Americans are magnesium deficient. Excess magnesium in the blood is freely filtered at the kidneys, and for this reason it is very difficult to overdose on magnesium from dietary sources alone.[4] However, there are a number of magnesium supplements available which make overdose possible, particularly in people with poor renal function, but severe hypermagnesemia can also occur without renal dysfunction.[5]
Isotopes
Magnesium has three stable isotopes: 24Mg, 25Mg, 26Mg. All are present in significant amounts (see table of isotopes above). About 79% of Mg is 24Mg. The isotope 28Mg is radioactive and in the 1950s to 1970s was made commercially by several nuclear power plants for use in scientific experiments. This isotope has a relatively short half-life (21 hours) and so its use was limited by shipping times.
26Mg has found application in isotopicgeology, similar to that of aluminium. 26Mg is a radiogenic daughter product of 26Al, which has a half-life of 717,000 years. Large enrichments of stable 26Mg have been observed in the Ca-Al-rich inclusions of some carbonaceous chondritemeteorites. The anomalous abundance of 26Mg is attributed to the decay of its parent 26Al in the inclusions. Therefore, the meteorite must have formed in the solar nebula before the 26Al had decayed. Hence, these fragments are among the oldest objects in the solar system and have preserved information about its early history.
It is conventional to plot 26Mg/24Mg against an Al/Mg ratio. In an isochron dating plot, the Al/Mg ratio plotted is27Al/24Mg. The slope of the isochron has no age significance, but indicates the initial 26Al/27Al ratio in the sample at the time when the systems were separated from a common reservoir.
Precautions
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. Magnesium powder is an explosive hazard. One should wear safety glasses while working with magnesium, and if burning it, these should include a heavy U.V. filter, similar to welding eye protection. The bright white light (including ultraviolet) produced by burning magnesium can permanently damage the retinas of the eyes, similar to welding arc burns.[6]
Water should not be used to extinguish magnesium fires, because it can produce hydrogen which will feed the fire, according to the reaction:[7]
Carbon dioxide fire extinguishers should not be used either, because magnesium can burn in carbon dioxide (forming magnesium oxide, MgO, and carbon).[8] A Class D dry chemical fire extinguisher should be used if available, or else the fire should be covered with sand or magnesium foundry flux. An easy way to put out small metal fires is to place a polyethylene bag filled with dry sand on top of the fire. The heat of the fire will melt the bag and the sand will flow out onto the fire.
↑Kontani M, Hara A, Ohta S, Ikeda T (2005). "Hypermagnesemia induced by massive cathartic ingestion in an elderly woman without pre-existing renal dysfunction". Intern. Med. 44 (5): 448–52. doi:10.2169/internalmedicine.44.448. PMID15942092.CS1 maint: Multiple names: authors list (link)
