tio2 rutile type

In a preferred technical solution, 3⁄40 2 is added to the Lide powder emulsion of the metathesis reaction step, and the mass fraction of 3⁄40 2 added is 10 to 33%, and the lithopone emulsion is desulfurized (mainly hydrosulfate ion or Elemental sulfur), slowly added 3⁄40 2 until the lithopone emulsion is colorless and transparent. The obtained sulfate ion can be recycled and reused in the production process. The chemical reaction equation is: 43⁄40 2 + HS— + OH— → SO/— + 5H 2 0

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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.

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