Magnesium oxide CAS:1309-48-4

Superior Thermal Endurance

Its melting point hits 2,852 °C, which supports its wide use in refractory goods and high-temperature crucible production.

Multifunctional Industrial Auxiliary

It improves the performance of rubber and plastic mixtures, and also plays catalytic and insulating roles in silicon steel manufacturing procedures.

Fire Suppression Effect

Adding this substance to building materials helps strengthen their fire-proof capability.

Applications in Medicine and Farming

It is processed into stomach acid neutralizers for pharmaceutical use, and supplied as magnesium nutrition additive for soil improvement and animal feeding.

Two Customized Product Forms

Light-grade (high specific surface area) and heavy-grade (high bulk density) specifications are both offered to match various specialized usage scenarios.

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Product Details

Magnesium oxide, the common name for magnesium oxide (MgO), is an alkaline earth metal oxide in white crystalline powder form. Its melting point reaches 2,852°C and boiling point hits 3,600°C, with a density of 3.58 at 25°C. It dissolves in acidic and ammonium salt solutions and slowly hydrates into magnesium hydroxide in water; contact with carbon dioxide-containing water generates magnesium bicarbonate. This product easily absorbs moisture and carbon dioxide from air, and will produce irritant fumes when thermally decomposed.

Magnesium oxide CAS:1309-48-4

Production Raw Materials and Processes

Manufacturers mainly produce magnesium oxide from magnesite, dolomite and seawater resources. The standard industrial method relies on calcining magnesite or dolomite to decompose raw ores. The seawater route precipitates magnesium hydroxide via calcium hydroxide addition, followed by calcination to get final MgO. Production can also utilize magnesium chloride brine from seawater or bromine extraction waste liquid: sodium hydroxide or sodium carbonate precipitates magnesium hydroxide/basic magnesium carbonate, and calcination converts precipitates into magnesium oxide. Chinese factories primarily utilize magnesite, dolomite, natural brine and solid salt ores as production feedstocks.

Production Volume and Application of Low-Temperature Light-Burned Magnesia

Magnesium oxide accounts for around 75% of total magnesium chemical production, leading all magnesium-based chemical products. Light-burned magnesia calcined below 900°C has low stacking density, large specific surface area and powerful adsorption performance. It acts as catalyst and reinforcing filler for rubber, raw material of magnesium oxychloride cement with magnesium chloride, and fire retardant for building materials. In medicine, it treats hyperacidity and gastric ulcers; compounding with calcium carbonate reduces its laxative effect. It is also added to animal feed and farm fertilizers as magnesium supplements.

Magnesium oxide CAS:1309-48-4

Mid-Temperature and High-Temperature Calcined Magnesia Grades

Magnesia sintered at 950–1050°C has higher bulk density, stable particle distribution and stronger hydration activity. Coated on silicon steel sheets, it reacts with surface silicon dioxide to form magnesium silicate barrier layers, preventing sheet sintering during high-temperature processing. Heavy-burned magnesia calcined at 1500–1800°C features high density, small specific surface area, superior heat resistance and low chemical activity (slow acid dissolution and hydration). It is widely adopted for high-temperature refractory products such as crucibles and furnace linings.

Magnesium oxide CAS:1309-48-4