Magnesite is an important industrial mineral composed of magnesium carbonate (MgCO3). Pure magnesite is theoretically 47.8% MgO and 52.2% CO2. It is the source of two-thirds of the 9 Mt of magnesia (MgO) used annually throughout the world; 25% is extracted from sea water, with the balance coming from brines or other mineral sources such as serpentinite or brucite.
Magnesite is used as a filler in plastics and paints, and as an agricultural fertiliser.
Caustic calcined magnesia (caustic magnesia) is formed by calcining magnesite at 700–1000C to produce a form of magnesia with high specific surface area and high reactivity. It is used in a wide variety of applications including:
animal feeds and fertilisers magnesia cements, flooring compounds and other building materials
environmental (water and effluent treatment, and flue gas desulphurisation) metallurgical flux flame retardants a source of magnesium chemicals for industries, including pharmaceutical.Dead burned magnesia(a sintered magnesia) is formed when magnesia is calcined at temperatures of 1600–2000C.
Its main use is in heat resistant linings. Electrofused magnesia is a strong, abrasion-resistant material used in premium grade refractories and ceramics. Magnesium metal can be produced from magnesite by electrolysis of magnesium chloride. World production of magnesium metal in 1998 was 369 000 t. Predictions for strong growth in demand for this strong, lightweight metal in the automotive industry has resulted in feasibility studies being undertaken in many places throughout the world, including South Australia.
TYPICAL MAGNESITE ORE ANALYSIS
MgCO3: 46,13 %
Fe2O3: 0,35 %
SiO2 : 0,25 %
SIZE OF PRODUCTS
MgCO3 for Metallurgical and Magnesia Production
3-150 mm MgCO3 For Ceramics and Paper
d98 45 micron