Magnesiumoksidia

Magnesiumoksidia, or magnesium oxide, is an inorganic compound with the formula MgO. It is a white, odorless, hygroscopic solid with a very high melting point (about 2852°C) and a density around 3.58 g/cm3. In the solid, magnesium and oxide ions form a rock-salt type lattice. The mineral periclase is the natural form of MgO, and industrially it is produced by calcining magnesium carbonate or dolomite: MgCO3 → MgO + CO2. Typical calcination temperatures range from 900 to 1000°C, with higher temperatures for higher purity.

Magnesium oxide is only sparingly soluble in water and is strongly basic. When it hydrates, it forms magnesium hydroxide: MgO + H2O → Mg(OH)2. It readily dissolves in acids, yielding soluble magnesium salts and water.

Applications include use as a refractory material and a high-temperature lining for furnaces and kilns, thanks to its chemical stability and high melting point. It is employed as a refractory binder and as an additive in cement and ceramics. Magnesium oxide also serves as a source of the nutrient magnesium in agriculture, and in medicine as an antacid and laxative. In the food industry, it is used as a food additive (E530) to adjust acidity and as a carrier for minerals. Additional uses include desulfurization and various chemical syntheses.

Safety and handling: magnesium oxide dust can irritate the eyes, skin, and lungs; inhalation should be minimized. It is relatively low in acute toxicity, but prolonged exposure should be avoided. It should be stored in a dry, tightly closed container to prevent hydration and clumping.