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 the pigment itself can vary in shade over time, ranging from pure white all the way to grey or even black. To suppress this effect, a dopant may be used, such as a 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.
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The CaCO3 and TiO2 factory not only provides a reliable supply of these materials to industries but also contributes to the local economy by creating job opportunities and generating revenue. The factory employs skilled workers in various departments such as production, quality control, and maintenance. It also collaborates with suppliers and distributors to ensure efficient transportation and delivery of CaCO3 and TiO2 to customers worldwide.