Magnesite

Magnesite is a mineral which has theoretically %52.3 CO₂ and %47.7 MgO in its compound, with hardness of 3.5 - 4.5 in Mohr scale, density of approx. 2.5 gr/cm³ and with melting point of 2800 ⁰C . It is analteration product of serpentine and similar rocks with a hard and complex structure. It includes impurities such as SiO₂, CaO, Fe₂O₃, Al₂O₃with varying degrees. Amount of these impurities and their ratio between each other, determine the quality of magnesite.
            Application of raw magnesite is very limited. Being one of the most important inputs of refractory industry, magnesite loses its CO₂ content when heated. It turns into calcined magnesite at 900⁰C and sintered magnesite at 1800⁰C. Chemical formula is MgO for both of them. Calcined magnesite retains its reactive ability with %3-5 Loss of Ignition (L.O.I) value but sintered magnesite loses its reactive ability due to zero L.O.I. Sintered magnesite is one of the most heat-durable materials because of high melting point(2800^oC). This quality makes it the basic raw material of refractory brick and mortars used in iron-steel and cement industry.
            Sintered magnesite constitutes %90 of total consumption of magnesite. Other %10 is consumed as calcined magnesite in industries such as animal feed premixes and abrasives. Raw magnesite is consumed in insulation, rubber, ceramic, paint, pharmacy and cosmetic sectors.

            MgO, which is defined as sintered and calcined magnesite, is obtained naturally by burning raw magnesite (MgCO₃) ore, or by processing magnesium salts in sea water and underground MgCl₂ (Bishofit) layers. It is also obtained synthetically by enabling chemical reactions with some other minerals such as Dolomite.