china cheap barium sulphate superfine

Firstly, calcium carbonate factories can be categorized into two primary types natural and synthetic. Natural calcium carbonate factories extract limestone, marble, or chalk, all of which are rich in calcium carbonate, from the earth's crust. These materials are then processed through grinding and purification techniques to produce calcium carbonate powder. On the other hand, synthetic calcium carbonate factories create the compound through a chemical reaction between calcium oxide (quicklime) and carbon dioxide. This method is often used when a purer form of calcium carbonate is required.

...

Although barium sulfate is almost completely inert, zinc sulfide degrades upon exposure to UV light, leading to darkening of the pigment. The severity of this UV reaction is dependent on a combination of two factors; how much zinc sulfide makes up the pigments formulation, and its total accumulated UV exposure. Depending on these factors Lithopone B301, Lithopone B311 powder itself may vary in shade over time, ranging from pure white all the way to grey or even black. To suppress this effect, a dopant might be used, like small amount of cobalt salts, which would be added to the formulation. This process creates cobalt-doped zinc sulfide. The cobalt salts help to stabilize zinc sulfide so it will not have as severe a reaction to UV exposure.

...
...