Magnesium is a chemical element with symbols Mg and atomic number 12. It is a shiny gray solid that has a close physical similarity to the other five elements in the second column (group 2, or alkaline earth metals) from the periodic table: all the elements of group 2 have the same electron configuration in the outer shell of electrons and similar crystal structures.
Magnesium is the ninth most abundant element in the universe. It produced a large, aging star of sequential addition of three helium nuclei to the carbon core. When the stars explode as supernovae, much of the magnesium is dumped into the interstellar medium where it can recycle into a new star system. Magnesium is the eighth most common element in Earth's crust and the fourth most common element on Earth (after iron, oxygen and silicon), which make up 13% of the planet's mass and most of the planet's mantle. This is the third largest element dissolved in seawater, after sodium and chlorine.
Magnesium occurs naturally only in combination with other elements, where it always has an oxidation state 2. The free element (metal) can be produced artificially, and is highly reactive (though in the atmosphere, it is immediately coated with a thin layer of oxide which partially inhibits reactivity - see passivation). Burning free metal with distinctive bright white light. This metal is now obtained primarily by electrolysis of magnesium salts obtained from salt water, and is used principally as a component in aluminum-magnesium alloys, sometimes called magnolium or magnelium . Magnesium is less dense than aluminum, and its alloys are appreciated for its combination of lightness and strength.
Magnesium is the eleventh element that is most abundant by the masses in the human body and is essential for all cells and about 300 enzymes. Magnesium ions interact with polyphosphate compounds such as ATP, DNA, and RNA. Hundreds of enzymes require magnesium ions to function. Magnesium compounds are used as common laxatives, antacids (eg, milk magnesia), and to stabilize abnormal nerve excitation or spasm of blood vessels under conditions such as eclampsia.
Video Magnesium
Characteristics
Physical properties
The magnesium element is a light gray-white metal, two-thirds the density of aluminum. It fades slightly when exposed to air, though, unlike other alkaline earth metals, the oxygen-free environment is not required for storage because magnesium is protected by a thin layer of oxide that is waterproof enough and difficult to remove. Magnesium has the lowest melting (923 K (1.202 Â ° F)) and the lowest boiling point is 1,363 K (1,994 Â ° F) of all alkaline earth metals.
Magnesium reacts with water at room temperature, although it reacts more slowly than calcium, a type of group of 2 metals. When submerged in water, the hydrogen bubbles form slowly on the metal surface - though, if the powder, reacts much faster. The reaction occurs faster with higher temperatures (see safety precautions). Reversible reactions Magnesium with water can be used to store energy and run magnesium based machines.
Magnesium also reacts exothermically with most acids such as hydrochloric acid (HCl), producing chloride and hydrogen gas, similar to HCl reactions with aluminum, zinc, and many other metals.
Chemical Properties
Flammability
Magnesium is highly flammable, especially when powdered or shaved into thin strips, although it is difficult to ignite en masse or bulk. The magnesium and magnesium alloy flame temperatures can reach 3,100 ° C (5,610 ° F), although the height of the flame above the burning metal is usually less than 300 mm (12 inches). Once ignited, such a fire is difficult to extinguish, because burning continues in nitrogen (forming magnesium nitride), carbon dioxide (forming magnesium oxide and carbon), and water (forming magnesium oxide and hydrogen). This property was used in firearms during the bombing of cities in World War II, where the only practical civil defense was to ignite a burning fire under dry sand to get rid of the atmosphere from burning.
Magnesium can also be used as a flame for thermite, a mixture of aluminum powder and iron oxide powder that only light up at very high temperatures.
Light source
When burning in the air, magnesium produces a brilliant white light that includes powerful ultraviolet waves. Magnesium powder (flash powder) is used for subject lighting in the early days of photography. Then, magnesium filaments are used in electrically disposable photographic flashbulbs ignited. Magnesium powders are used in fireworks and sea flares where brilliant white light is needed. It is also used for a variety of theatrical effects, such as lightning, flash of a gun, and supernatural appearance.
Genesis
Magnesium is the eighth most abundant element in the Earth's crust with mass and tied in seventh place with iron in molarity. It is found in large deposits of magnesite, dolomite, and other minerals, and in mineral water, where magnesium ions dissolve.
Although magnesium is found in over 60 minerals, only dolomite, magnesite, brucite, carnallite, talc, and olivine have commercial importance.
The Mg 2 cation is the second most abundant cation in seawater (about 1/8 of the mass of sodium ions in a given sample), which makes marine and sea salt an attractive source for Mg. To extract magnesium, calcium hydroxide is added to seawater to form a precipitate of magnesium hydroxide.
- MgCl
2 Ca (OH)
2 -> Mg (OH)
2 CaCl
2
Magnesium hydroxide (brucite) is insoluble in water and can be filtered and reacted with hydrochloric acid to produce concentrated magnesium chloride.
- Mg (OH)
2 2 HCl -> MgCl
2 2 H
2 O
From magnesium chloride, electrolysis produces magnesium.
Maps Magnesium
Form
Alloy
In 2013, the consumption of magnesium alloy is less than one million tons per year, compared with 50 million tons of aluminum alloy. Its use is historically limited by its tendency to corrodate, creep at high temperatures, and burn.
Corrosion
The presence of iron, nickel, copper, and cobalt greatly activates corrosion. Greater than a very small percentage, this metal precipitates as an intermetallic compound, and local precipitates serve as an active cathodic site that reduces water, causing the loss of magnesium. Controlling the amount of this metal increases corrosion resistance. Manganese is enough to overcome the corrosive effect of iron. This requires proper composition control, increasing the cost. Adding cathodic toxins captures hydrogen atoms in metal structures. This prevents the formation of free hydrogen gas, an important factor of corrosive chemical processes. The addition of about one in three hundred parts of arsenic reduces the corrosion rate in a salt solution by a factor of nearly ten.
High-temperature and flammable creep
Research shows that the magnesium tendency to creep at high temperatures is removed by the addition of scandium and gadolinium. The burning ease is greatly reduced by the small amount of calcium in the alloy.
​​Compound
Magnesium forms important industrial and biological compounds, including magnesium carbonate, magnesium chloride, magnesium citrate, magnesium hydroxide (milk magnesia), magnesium oxide, magnesium sulfate, and magnesium sulfate heptahydrate (Epsom salts).
Isotope
Magnesium has three stable isotopes: 24 Mg , 25 Mg and 26 Mg . All present in significant amounts (see isotope table above). About 79% of Mg is 24 Mg . Isotopes 28 Mg is radioactive and in the 1950s to the 1970s were produced by several nuclear power plants for use in scientific experiments. This isotope has a relatively short half-life (21 hours) and its use is limited by delivery time.
Nuclide 26 Mg has an app which are found in isotope geology, similar to aluminum. 26 Mg is the product's radiogenic daughter 26 Al , which has a half-life of 717,000 years. Excessive amount of stable 26 Mg has been observed in Ca-Al-rich inclusions of several carbon chondrite meteorites. The abundance of this anomaly is attributed to its parent decay 26 Al in inclusion, and the researchers conclude that the meteorite is formed in the solar nebula before <26> Al has been broken. It is one of the oldest objects in the solar system and contains preserved information about early history.
It is conventional to plan 26 Mg / 24 Mg against the ratio of Al/Mg. In the isokron dating plot, the plotted Al/Mg ratio is 27
24
Mg . The isochron slope does not have any age significance, but it shows 26 Al / 27 Al ratios in the sample at the time the system is separated from the common reservoir.
Production
China is the dominant supplier of magnesium, with around 80% of the world market share. China is almost completely dependent on the Pidgeon silicothermic process (oxide reduction at high temperatures with silicon, often provided by ferrocyanone alloys in which the iron only becomes a spectator in reaction) to obtain metal. This process can also be carried out with carbon at about 2300 ° C:
- 2MgO
(s) Si
(s) 2CaO
(s) -> 2Mg
(g) Ca
2 SiO
4 (s) - MgO
(s) C
(s) -> Mg
(g) CO
(g)
In the United States, magnesium is obtained primarily by the Dow process, with electrolysis of fused magnesium chloride from saltwater and seawater. Copy solution containing Mg 2 ion was first treated with lime (calcium oxide) and precipitated magnesium hydroxide collected:
- Mg 2 (aq) CaO
(s) H
2 2
(aq) Mg (OH)
2 (s)
The hydroxide is then converted to partial hydrate of magnesium chloride by treating the hydroxide with hydrochloric acid and heating the product:
- Mg (OH)
2 (s) 2 HCl -> MgCl
2 (aq ) 2 H
2 O
(l)
Garam kemudian dielektrolisis dalam keadaan cair. Pada katoda, Mg 2
ion dikurangi dua elektron menjadi logam magnesium:
- Mg 2
2
e -
-> Mg
Pada anode, masing-masing pasangan Cl -
ion teroksidasi menjadi gas klor, melepaskan dua elektron untuk menyelesaikan rangkaian:
- 2 Cl -
-> Cl
2 (g) 2
e -
The new process, solid oxide membrane technology, involves the reduction of MgO electrolytes. At the cathode, Mg 2 ion is reduced by two electrons into magnesium metal. Electrolytes are yttria-stabilized zirconia (YSZ). Anode is molten metal. In YSZ/anode metal metal O 2 - is oxidized. The graphite layer is adjacent to the molten metal anode, and at this interface carbon and oxygen react to form carbon monoxide. When silver is used as a molten metal anode, no reducing carbon or hydrogen is required, and only oxygen gas evolves on the anode. It has been reported that this method provides a 40% reduction in the cost per pound during the electrolytic reduction method. This method is more environmentally friendly than others because much less emitted carbon dioxide.
The United States has traditionally been the world's leading supplier of this metal, supplying 45% of world production even recently in 1995. Currently, US market share reaches 7%, with one remaining domestic producer, US Magnesium, Renco Group companies in Utah born of Magcorp who is now dead.
History
The name magnesium comes from the Greek word for a district in Thessaly called Magnesia. It is associated with magnetite and manganese, which also originate from this region, and required differentiation as a separate substance. Look at the manganese for this history.
In 1618, a farmer at Epsom in England tried to give his cow water from a well there. The cows refuse to drink because of the bitter taste of the water, but the farmer realizes that the water seems to heal scratches and rashes. This substance is known as Epsom salts and its famous spreading. It is finally recognized as hydrated magnesium sulfate, MgSO
4 Ã, Â · 7 H
2 O .
The metal itself was first isolated by Sir Humphry Davy in England in 1808. He used electrolysis on a mixture of magnesium and mercury oxide. Antoine Bussy prepared it in coherent form in 1831. Davy's first suggestion for a name was magnium, but the name magnesium is now used.
Use as metal
Magnesium is the third most commonly used structural metal, following iron and aluminum.
The main applications of magnesium are, in order: aluminum alloys, die-casting (alloying with zinc), eliminating sulfur in iron and steel production, and titanium production in the Kroll process.
Magnesium is used in super strong and lightweight alloy materials. For example, when infused with silicon carbide nanoparticles, it has a very high specific strength.
Historically, magnesium was one of the major 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.
Germany created the name "Electron" for magnesium alloy, a term still used today. In the commercial aerospace industry, magnesium is generally limited to engine-related components, due to fires and corrosion hazards. Currently, the use of magnesium alloy in space is increasing, fueled by the importance of fuel economy. Development and testing of new magnesium alloys continues, especially Electron 21, which (in testing) has proven to be suitable for aircraft components, internal, and airframe. The European Community runs three R & amp; D magnesium in Aerospace priority of the Six Framework Program.
In the form of thin bands, magnesium is used to purify the solvent; for example, preparing ethanol super dry.
Planes
- Wright Aeronautical uses magnesium crankcase on WWII's Wright Duplex Cyclone aviation engine. This presents a serious problem for the earliest model of the Boeing B-29 heavy bomber when the engine fire inside the plane turned on the crankcase engine. The resulting combustion is as hot as 5,600 Â ° F (3,100 Â ° C) and can cut the wing spar from the fuselage.
Automotive
- Mercedes-Benz uses Electron alloys in the body of the early model Mercedes-Benz 300 SLR; these cars ran (with success) in Le Mans, Mille Miglia, and other world-class racing events in 1955.
- Porsche used a magnesium alloy frame on 917/053 that won Le Mans in 1971, and continued to use magnesium alloys for its engine block due to heavy advantages.
- The Volkswagen Group has been using magnesium in its engine components for years.
- Mitsubishi Motors uses magnesium for paddle shifters.
- BMW uses magnesium alloy blocks on their N52 machines, including aluminum alloy inserts for cylinder walls and cooling jackets surrounded by AJ62A high temperature magnesium alloy. This machine is used worldwide between 2005 and 2011 in various models of series 1, 3, 5, 6, and 7; and Z4, X1, X3, and X5.
- Chevrolet uses AE44 magnesium alloy in Corvette Z06 2006.
Both AJ62A and AE44 are the latest developments in high temperature magnesium low-creep alloys. A common strategy for such alloys is to form an intermetallic precipitate at the grain boundary, for example by adding mischmetal or calcium. The development of new alloys and lower costs that make magnesium competitive with aluminum will increase the number of automotive applications.
Electronics
Due to its low weight and good mechanical and electrical properties, magnesium is widely used for the manufacture of mobile phones, laptops and tablet computers, cameras, and other electronic components.
More
Magnesium, which is available and relatively non-toxic, has various uses:
- Magnesium is flammable, burns at temperatures of about 3,100 ° C (3,370 ° K, 5,610 ° F), and the magnesium tape autoignition temperature is approximately 473 ° C (746 Â ° K; 883 Â ° F). It produces a strong, bright, white light when it burns. Magnesium high burning temperature makes it a useful tool for starting an emergency fire. Other uses include flash photography, flares, fireworks, and fireworks fireworks. Magnesium is also often used to light thermites or other materials that require high ignition temperatures.
- In the form of bends or ribbons, to prepare Grignard reagents, which are useful in organic synthesis.
- As an additive agent in conventional propellant and the production of nodular graphite in cast iron.
- As a reducing agent to separate uranium and other metals from its salts.
- As a sacrificial anode (galvanic) to protect vessels, underground tanks, pipelines, buried structures, and water heaters.
- Combined with zinc to produce zinc sheets used in photo plates in the printing industry, dry cell battery walls, and roofs.
- As a metal, the primary use of this element is as an alloy alloy for aluminum with aluminum-magnesium alloys is used primarily for beverage cans, sports equipment such as golf clubs, fishing reels, and arches and arches. Special, high-quality car wheels of magnesium alloy are called "mag wheels", although the term is often misused for aluminum wheels. Many car and aircraft manufacturers have made machines and body parts of magnesium.
- The magnesium battery has been commercialized as a primary battery, and is an active research topic for rechargeable secondary batteries.
Security precautions
Magnesium and alloyed metals may be an explosive hazard; they are highly flammable in pure form when liquid or in powder or ribbon form. Liquid combustion or magnesium reacts violently with water. When working with magnesium powder, safety glasses with eye protection and UV filters (such as the use of welders) are used because magnesium combustion produces ultraviolet light which can damage the retina of the human eye permanently.
Magnesium mampu mengurangi air dan melepaskan gas hidrogen yang sangat mudah terbakar:
- Mg (s) 2 H
2 O (l) -> Mg (OH)
2 (s) H
2 (g)
Therefore, water can not extinguish the magnesium fire. The resulting hydrogen gas intensifies the fire. Dry sand is an effective blocking agent, but only on a relatively flat and flat surface.
Magnesium reacts with exothermic carbon dioxide to form magnesium oxide and carbon:
- 2 Mg CO
2 -> 2 MgO C (s)
Therefore, carbon dioxide fuels rather than extinguish magnesium flame.
Burning magnesium can be extinguished by using a Class D dry chemical extinguisher, or by sealing the fire with a sand or magnesium foundry flux to remove the air source.
Useful compounds
Magnesium compounds, especially magnesium oxide (MgO), are used as refractory in furnace layers to produce iron, steel, nonferrous metals, 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 on fireproof cable.
Magnesium that reacts with alkyl halide provides Grignard reagent, which is a very useful tool for preparing alcohol.
Magnesium salts are included in various foods, fertilizers (magnesium is a component of chlorophyll), and microbial culture media.
Magnesium sulfite is used in the manufacture of paper (sulfite process).
Magnesium phosphate is used for fireproof wood used in construction.
Magnesium hexafluorosilicate is used for moth-resistant textiles.
Biological role
Action mechanism
Important interactions between phosphate ions and magnesium make magnesium important for basic nucleic acid chemistry of all cells of all living organisms known. More than 300 enzymes require magnesium ions for their catalytic action, including all enzymes that use or synthesize ATP and which use other nucleotides to synthesize DNA and RNA. ATP molecules are usually found in chelate with magnesium ions.
Food sources, recommended intake, and supplementation
Spices, nuts, cereals, chocolate and vegetables are rich sources of magnesium. Green leafy vegetables such as spinach are also rich in magnesium.
In the UK, the recommended daily magnesium value is 300 mg for men and 270 mg for women. In the US, Recommended Dietary Allowances (RDAs) are 400 mg for men ages 19-30 and 420 mg for older ones; for women 310 mg for ages 19-30 and 320 mg for older ones.
Many magnesium pharmaceutical preparations and dietary supplements are available. In two human trials of magnesium oxide, one of the most common forms of magnesium diet supplement because of its high magnesium content per weight, it is less bioavailable than magnesium citrate, chloride, lactate or aspartate.
Metabolism
An adult has 22-26 grams of magnesium, with 60% in order, 39% intracellular (20% in skeletal muscle), and 1% extracellular. Serum levels are usually 0.7-1.0 mmol/L or 1.8-2.4 mEq/L. Serum magnesium levels may be normal even when intracellular magnesium is lacking. Mechanisms for maintaining serum magnesium levels vary in gastrointestinal absorption and renal excretion. Intracellular magnesium is correlated with intracellular potassium. Increased magnesium lowers calcium and may prevent hypercalcaemia or cause hypocalcemia depending on the initial level. Both conditions of low and high protein intake inhibit the absorption of magnesium, as do the amount of phosphate, phytate, and fat in the intestine. Foods that are not absorbed by magnesium are excreted in the stool; absorbed magnesium is excreted in urine and sweat.
Detection in serum and plasma
Magnesium status can be assessed by measuring serum magnesium and erythrocyte concentrations coupled with urinary and feses magnesium, but intravenous magnesium loading tests are more accurate and practical. Retention of 20% or more of the injected amount indicates deficiency. No biomarkers are formed for magnesium.
Magnesium concentrations in plasma or serum can be monitored for efficacy and safety in those receiving therapeutic drugs, to confirm the diagnosis of potential toxicity victims, or to assist in forensic investigations in cases of fatal overdose. Newborn children of mothers who receive parenteral magnesium sulfate during labor may exhibit toxicities with normal serum magnesium levels.
Disadvantages
Low plasma magnesium (hypomagnesemia) is common: found in 2.5-15% of the general population. The main cause of deficiency is low food intake: fewer than 10% of people in the United States meet the recommended dietary allowance. Other causes are increased kidney or gastrointestinal loss, increased intracellular displacement, and proton pump antacid inhibitor therapy. Most are asymptomatic, but symptoms can be referred to neuromuscular, cardiovascular, and metabolic dysfunction. Alcoholism is often associated with magnesium deficiency. Low serum magnesium levels are chronically associated with metabolic syndrome, type 2 diabetes mellitus, fasciculation, and hypertension.
Therapy
- Intravenous magnesium is recommended by the 2006 ACC/AHA/ESC Guidelines for the Management of Patients with Ventricular Arrhythmias and Sudden Cardiac Mortality Prevention for patients with ventricular arrhythmias associated with torsades de pointes that come with long QT syndrome; and for the treatment of patients with induced digoxin arrhythmias.
- Magnesium sulfate - intravenous - used for the management of pre-eclampsia and eclampsia.
- Hypomagnesemia, including those caused by alcoholism, can be recovered by administration of oral or parenteral magnesium depending on the degree of deficiency.
- There is limited evidence that magnesium supplements can play a role in migraine prevention and treatment.
Sorted by magnesium salt type, other therapeutic applications include:
- Magnesium sulfate, such as the heptahydrate called Epsom salt, is used as bath salts, laxatives, and highly soluble fertilizers.
- Magnesium hydroxide, suspended in water, is used in antacid milk and magnesia laxatives.
- Magnesium chloride, oxide, gluconate, malate, orotation, glycinate, ascorbate, and citrate are all used as oral magnesium supplements.
- Magnesium borate, magnesium salicylate, and magnesium sulfate are used as antiseptics.
- Magnesium bromide is used as a mild sedative (this action is caused by bromide, not magnesium).
- Magnesium stearate is a slightly flammable white powder with lubricating properties. In pharmaceutical technology, it is used in the manufacture of pharmacology to prevent the tablet from sticking to the equipment while compressing the ingredients into tablet form.
- Magnesium carbonate powder is used by athletes such as gymnasts, weightlifting, and climbers to remove palm sweat, prevent clinging, and increase grip on gym equipment, lifting bars, and climbing rocks.
Overdose
Overdose from food sources alone is not possible because of the excess magnesium in the blood is immediately filtered by the kidneys, and overdose is more likely in the presence of impaired renal function. Nevertheless, megadosis therapy has caused death in young children, and severe hypermagnesemia in a woman and a young girl who has a healthy kidney. The most common symptoms of overdose are nausea, vomiting, and diarrhea; Other symptoms include hypotension, confusion, slowing heartbeat and respiratory rate, other mineral deficiencies, coma, cardiac arrhythmias, and death from heart attacks.
Works in factory
Plants require magnesium to synthesize chlorophyll, essential for photosynthesis. Magnesium at the center of the porphyrin ring in chlorophyll function in a manner similar to iron at the center of the porphyrin ring in heme. Magnesium deficiency in plants causes late seasonal seasoning between leaf veins, especially in older leaves, and can be repaired by applying a rapidly washed epsom salt, or dolomite crushed limestone, to the soil.
See also
- List of countries based on magnesium production
- Magnesium oil
Note
References
External links
- Magnesium on Periodic Video Table (University of Nottingham)
- Chemistry in its elemental podcast (MP3) from the Royal Society of Chemistry's Chemistry World: Magnesium
- "Magnesium - a versatile and often overlooked element: a new perspective focusing on chronic kidney disease". Kidney Clinic J . 5 (Suppl 1). February 2012.
Source of the article : Wikipedia
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