Hebei Messi Biology Co., Ltd. stated that basic magnesium carbonate has many compositions, and the composition is generally expressed as XMgCO3·YMg(OH)2·ZH2O. Among them, there are several ratios of X, Y, and Z, which can be 4:1:4, 4:1:5, 4:1:6, 4:1:7, 3:1:3, 3:1:4, etc. Basic magnesium carbonate is a white crystalline or amorphous powder, non-toxic, odorless, stable in the air; slightly soluble in water, the aqueous solution is weakly alkaline, and easily soluble in acid and ammonium salt solution; it decomposes and releases carbon dioxide when it encounters dilute acid; it decomposes when heated to above 300°C to generate water, carbon dioxide and magnesium oxide.
Basic magnesium carbonate has a wide range of uses, mainly used in rubber rolling, rubber making, rubber, dyes, paints, electronics, medicine, food, flour improvers and other industries. It is a good desiccant, wear-resistant and heat-insulating material, and is also one of the raw materials for preparing high-purity magnesium oxide.
Basic magnesium carbonate can be obtained under certain conditions by mixing soluble magnesium salts and carbonates. Generally, the product is heavy or light in weight based on the sedimentation volume (bulk density) of basic magnesium carbonate obtained after the reaction and the content of magnesium oxide. Heavy magnesium carbonate is commonly used in food, cosmetics and pharmaceutical industries. The sedimentation volume of light magnesium carbonate is generally required to be 6-7ml/g, and the sedimentation volume of heavy magnesium carbonate is below 1.5ml/g. In other words, the larger the sedimentation volume, the lighter the finished product tends to be.
Generally, 3MgCO3·Mg(OH)2·3H2O represents light magnesium carbonate, and 3MgCO3·Mg(OH)2·4H2O and 4MgCO3·Mg(OH)2·4H2O represent heavy magnesium carbonate. The content is calculated based on magnesium oxide (MgO), and the heavy magnesium carbonate should be 40.0% to 43.5%.