Introduction

• Magnesium is a chemical element with the symbol Mg and atomic number 12.

• Its common oxidation number is +2.

• It is an alkaline earth metal and the eighth-most-abundant element in the Earth's crust

• Due to magnesium ion's high solubility in water, it is the third-most-abundant element dissolved in seawater.

• The sea contains trillions of tonnes of magnesium, and this is the source of much of the 300,000 tonnes now produced annually.

• It has the melting point at 650.0 °C and boiling point at 1107.0 °C

Production Of Magnesium• 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.

• Traditionally magnesium is produced from dolomite and magnesite ore, as well as magnesium chloride.

• 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 percent magnesium chloride.

• The magnesium chloride at these sources still contains significant amounts of water and must be dried before it can be electrolyzed to produce metal.

Magnesium Production Plan

Electrolysis Of Magnesium• Magnesium is obtained principally by electrolysis of fused

magnesium chloride from brines, wells, and sea water.

• At the cathode, the Mg2+ ion is reduced by two electrons to magnesium metal:

Mg2+ + 2 e− → Mg

• At the anode, each pair of Cl− ions is oxidized to chlorine gas, releasing two electrons to complete the circuit:

2 Cl− → Cl2 (g) + 2 e−