Alkaline magnesium carbonate has good thermal stability, non-toxic, does not produce toxic or volatile gas, low price, is an inorganic environmentally friendly flame retardant. Basic magnesium carbonate (thermal decomposition temperature 220 ~ 550 ℃) than magnesium hydroxide (thermal decomposition temperature 300 ~ 340 ℃) and aluminum hydroxide (thermal decomposition temperature 180 ~ 200 ℃) thermal decomposition temperature range is wider.
After the combustion of basic magnesium carbonate decomposition heat absorption, the release of flame-retardant gas CO2 and water vapor, dilute the oxygen on the surface of the burning material and reduce the temperature of the surface of the burning material, and the generation of active magnesium oxide attached to the surface of the burning material to further prevent the burning process.
Magnesium carbonate is an inorganic compound with the chemical formula MgCO3, molecular weight 84.31, relative density 3.037. Appearance is white granular powder. It decomposes at 350℃ and loses carbon dioxide at 700℃. Slightly soluble in cold water, slowly soluble in acid.
Its trihydrate is colorless needle crystal, melting point 165℃, relative density 1.850. its pentahydrate is white monoclinic crystal, relative density 1.73, decomposed by heating in air. It can be obtained by passing carbon dioxide into the aqueous solution of magnesium salt while adding sodium carbonate, and the hydrate will be dried below 50℃ to obtain anhydrous material.
When magnesium carbonate is applied to...
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