Just for Students
Basic Facts about Magnesium Oxide and Magnesium Hydroxide

Martin Marietta Magnesia Specialties have been asked by quite a number of students preparing research papers to provide some basic information on the properties, manufacture and uses of magnesium oxide. In response to these requests we are pleased to provide information about MgO and Mg(OH)2 which we hope will be educational and interesting as well.

Magnesium Oxide’s Physical Properties
Chemical Formula: MgO
Physical State: solid
Molecular Weight: 40.31 g/mol
Color: white
Melting Point: 2827 +30ºC
Density: 3.58 g/cm3

Raw materials needed to produce Magnesium Oxide:

The majority of magnesium oxide produced today is obtained from the processing of naturally occurring minerals such as magnesite (magnesium carbonate), magnesium chloride rich brine, and seawater.

Large mineral deposits of magnesite are located in Austria, Brazil, Canada, China, the Commonwealth of Independent States (CIS), former Czechoslovakia, Greece, Turkey, North Korea, former Yugoslavia, and the U.S.

When heated from 700°C to 1000°C, magnesium carbonate thermally decomposes to produce magnesium oxide and carbon dioxide:

MgCO3 --heat-->MgO + CO2(gas)

Next: Production of MgO