About Magnesium Metal


History And Its Characteristics

The Metal itself was first produced by Sir Humphry Davy in England in 1808. He used electrolysis on a mixture of magnesia and mercuric 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.

MAGNESIUM is a chemical element, designated by the symbol Mg. It has the atomic number 12. A silvery-white metal that ignites easily in air and burns with a bright light. Although it is the eighth most abundant element in the universe and the seventh most abundant element in the earth’s crust, magnesium is never found free in nature.  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 producing a similar crystal structure.

Mg 1

Magnesium is the fourth-most-common element in the Earth as a whole (behind iron, oxygen and silicon), making up 13% of the planet’s mass and a large fraction of the planet’s mantle. Magnesium is produced in stars larger than 3 solar masses by fusing helium and neon in the alpha process at temperatures above 600 Mega Kelvin.

Metallurgy

Magnesium is inseparable part of modern metallurgy. Early investigations related to the constituents of railroad iron and steel, of heat stress and heat treatment and related problems in the manufacturing process. Other says that the chemistry of metals and metal alloys, properties of metals at high temperatures, the working of metal in the foundry process, and testing of metals for compliance with Government specifications. World War I and World War II show that fact. Then many chemical, mechanical and structural properties of aluminium and magnesium (also platinum, rhodium, irridium, and palladium) were investigated with military meaning. In the same time scientist try to understand the metals corrosion processes, the properties of magnesium alloys, the metallurgy of nickel and its alloys, the testing of tool steels, and the mechanical properties of cast iron.

 Occurrence

A wide variety of production methods can be used to refine magnesium metal.

This is due to both the fact that magnesium is so abundant, making production in many locations possible, and that the minor metal‘s end-use applications are so price sensitive, so as to encourage buyers to constantly be seeking the lowest possible cost source.

mg 3

Magnesium is found in solution in sea-water (about 1.3 kg m-3 magnesium) and in natural brines.  It is also found extensively in the ores magnesite (MgCO3) and dolomite (MgCO3.CaCO3).

Traditionally magnesium is produced from dolomite and magnesite ore, as well as magnesium chloride containing salt brines (naturally occurring salt deposits).

Electrochemical processes are used to extract the metal from dolomite and magnesite ore. When dolomite is crushed, roasted and mixed with seawater in large tanks, magnesium hydroxide settles to the bottom. Heating, mixing in coke, and reacting with chlorine, then produces molten magnesium chloride. This can be electrolyzed, releasing magnesium, which floats to the surface.

Magnesium is also extracted from salt brines, which contain about 10 perecent magnesium chloride. The sea contains trillions of tonnes of magnesium, and this is the source of much of the 850,000 tonnes now produced each year. It is prepared by reducing magnesium oxide with silicon, or by the electrolysis of molten magnesium chloride.

Mg 2

Its Manufacturing Process

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 hydroxide is added to seawater to form magnesium hydroxide precipitate.

MgCl2 + Ca(OH)2 → Mg(OH)2 + CaCl2

Magnesium hydroxide (brucite) is insoluble in water, so it can be filtered out and reacted with hydrochloric acid to obtain concentrated magnesium chloride.

Mg(OH)2 + 2 HCl → MgCl2 + 2 H2O

From magnesium chloride, electrolysis produces magnesium.

Applications Of Magnesium Metal

  • The greatest use of magnesium is as an alloying element in aluminum. In amounts ranging from less than 1 percent to approximately 10 percent, magnesium enhances the mechanical properties as well as the corrosion resistance of aluminum alloys.
  • In the iron and steel industry, small quantities of magnesium are added to white cast iron to transform graphite into spherical nodules, thereby significantly improving the strength and malleability of the iron. In addition, particulate magnesium blended with lime or other fillers is injected into liquid blast-furnace iron, where it improves mechanical properties of steel by combining with sulfur and oxygen.
  • Its Applications include the production of titanium, zirconium, uranium, and hafnium. By far the most important of these is in theKroll process for reducing titanium tetrachloride to titanium metal.
  • The application field of magnesium is Fire starter and shavings, sharpener, magnesium ribbon and electronic devices. 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.