Hebei Messi Biology Co., Ltd. stated that active magnesium oxide is magnesium oxide formed by calcining magnesium compounds below 900 degrees. The chemical activity of magnesium oxide can be expressed by the iodine absorption value (with performance indicators). The greater the chemical activity, the greater the iodine absorption value, and the lighter it is. When the iodine absorption value is 150-180, it is called high-activity magnesium oxide, when the iodine absorption value is 120-150, it is called medium-activity magnesium oxide, and when the iodine absorption value is 100-120, it is called low-activity magnesium oxide.
The raw materials for preparing magnesium compounds in my country include solid minerals such as magnesite, brucite, dolomite, etc.; liquid resources include seawater and brine containing magnesium ions. The main methods for synthesizing active magnesium oxide are: magnesite calcination method, dolomite carbonization method, serpentine acid leaching method, brine carbon ammonium method and brine carbonization method.
The mineral raw materials for synthesizing active magnesium oxide mainly include magnesite, breccia and dolomite. In traditional industry, magnesium oxide is mainly produced from these ores as raw materials. Its main production methods include: magnesite calcination method, dolomite carbonization method, serpentine acid leaching method, magnesia powder-sulfuric acid-ammonium bicarbonate method, etc.
Active magnesium oxide, molecular formula MgO, relative molecular mass 40.30. Its chemical composition, physical form and other indicators are not much different from ordinary magnesium oxide, but some indicators of activated magnesium oxide are different from those of ordinary magnesium oxide; such as suitable particle size distribution, average particle size: <2μm (2000nm); microscopic morphology is irregular particles or nearly spherical particles or flaky crystals; the activity expressed by citric acid (CAA value) is 12~25s (the smaller the value, the higher the activity); the activity expressed by iodine absorption value is 80~120 (mgI2/100gMgO); the specific surface area is between 5~20m3/g, and the apparent specific volume is between 6~8.5mL/g. In addition, due to the high activity of this magnesium oxide, it is easy to absorb water, and sometimes chemical treatment is required for protection.
The active magnesium oxide content is low, and other substances may have been added. Or after encountering air, it is easy to absorb water and carbon dioxide and gradually become basic magnesium carbonate. Light products are faster, and heavy products are faster. Combined with water to form magnesium hydroxide, it is slightly alkaline. This leads to a decrease in content!