Properties
White monoclinic crystal or amorphous powder. The composition is generally expressed as xMgCO3. yMg(OH)z. zH20. Non-toxic, odorless, stable in air. Relative density 2.16. Slightly soluble in water, the aqueous solution is weakly alkaline. The solubility in water is 0.02% (15℃). It is easily soluble in acid and ammonium salt solution, and decomposes and releases carbon dioxide when it encounters dilute acid. It decomposes when heated to above 300℃ to produce water, carbon dioxide and magnesium oxide.
Preparation method
Dolomite carbonization method: dolomite and coal are crushed and mixed, calcined at 1000-1200℃, and then water is added to make dolomite lime slurry. After carbonization, filter pressing, direct steam pyrolysis, filter pressing, drying, crushing, and packaging, the finished basic magnesium carbonate is obtained.
Brine and limestone carbonization method: limestone is calcined with anthracite, emulsified with water, and reacted with brine to form magnesium hydroxide precipitation, which is then carbonized, pyrolyzed, washed and dehydrated, dried and crushed to obtain the finished product of basic magnesium carbonate.
Soda ash method: First dilute the raw bittern with water to about 200 86 and add it to the reactor. Under stirring, slowly add 20. Be of clear alkali solution, which changes from good fluidity to tofu-like viscosity. When the fluidity is restored, the stirring is stopped and the reaction temperature is maintained at about 55°C. After the reaction is completed, it is vacuum filtered twice, washed, crushed, dried, crushed, air-selected, and packaged to obtain the finished product of basic magnesium carbonate.
Carbon ammonium method: See light magnesium oxide.
Uses
It is used as an excellent filler and reinforcing agent for rubber products. It can be used as a heat-insulating, high-temperature resistant fireproof and heat-insulating material. Asbestos light magnesium carbonate is an excellent insulating material used in shipbuilding and boiler manufacturing. It can also be used to manufacture high-grade glass products, magnesium salts, pigments, paints and daily chemicals. It is used as an antacid in medicine. It can also be used as a desiccant, color preservative, carrier, and anti-caking agent.
Safety
For export products, it is lined with polyethylene plastic bags, then with kraft paper bags, and packaged with sacks or woven bags on the outside; basic magnesium carbonate for heat preservation is packaged in latex bags; basic magnesium carbonate for industrial use is lined with polyethylene film bags and packaged with plastic woven bags on the outside. The net weight of each bag is 20kg. It should be stored in a ventilated, dry warehouse to prevent moisture. During transportation, it should be covered with rainproof cloth to avoid moisture. Handle it with care during loading and unloading to prevent damage to the packaging and contact with acid. In case of fire, it can be put out with water or various fire extinguishers.