Heavy calcium carbonate relative molecular weight of 100.09 heavy calcium carbonate white powder, colorless, tasteless. Stabilize in the air. Almost insoluble in water, insoluble in alcohol. In case of dilute acetic acid, dilute hydrochloric acid, dilute nitric acid bubble boiling, and dissolved. Heated to 898 ℃, it begins to decompose into calcium oxide and carbon dioxide. Heavy calcium carbonate, or bicalcium, is made from natural carbonate minerals such as calcite, marble and limestone. It is a commonly used powdery inorganic filler with high chemical purity, high inertia, no chemical reaction, good thermal stability, no decomposition below 400 ℃, high whiteness, low oil absorption, low refraction, soft quality, dry, no crystalline water, Low wear value of hardness, non-toxic, tasteless, odorless, good dispersion and so on.
There are two kinds of production process of heavy calcium carbonate. Dry production process: first, pick out calcite, limestone, chalk, shell, etc from the quarry by hand to remove gangue; then use a crusher to coarse crush the limestone and then grind it with Ramon (pendulum) to produce fine limestone powder. The grinding powder is classified by classifier, and the powder that meets the grain size requirement is packed into storage, otherwise, it will return to the mill to grind the powder again. The process of wet production: first, the suspensions made from dry fine powder were placed in the mill to further comminute, and after dehydration and drying, ultrafine heavy calcium carbonate was prepared.
particle shape
The shape of heavy calcium carbonate is irregular, the particle size is different, and the particle has a certain angle, rough surface, wide particle size distribution, larger particle size, the average particle size is generally 1 ~ 10 μ m. Heavy calcium carbonate can be divided into coarse ground calcium carbonate (> 3 μ m), fine grinding calcium carbonate) (1 3 μ m), ultrafine calcium carbonate) according to its original average diameter (d). The powder characteristics of 5 μ m heavy calcium carbonate are: a. The shape of particles is irregular. The particle size distribution is wider. The particle size is larger.
应用领域application area
At present, calcium carbonate has been widely used in papermaking, plastic film, chemical fiber, rubber, adhesive, sealant, daily chemical industry, cosmetics, building materials, coatings, paint, ink, grease, wax, putty, felt packaging, medicine, etc. In foods (such as gum, chocolate) and fodder, their functions include increasing the volume of products, reducing costs, improving processing properties (such as adjusting viscosity, rheological properties, vulcanizing properties), improving dimensional stability, reinforcing or semi-reinforcing, Improve printing performance, improve physical properties (such as heat resistance, extinction, wear resistance, flame retardancy, whiteness, gloss, etc.).
