Barium sulfide is the inorganic compound with the formula BaS. Like other chalcogenides of the alkaline earth metals, BaS is a short wavelength emitters for electronic displays. It is colorless, although like many sulfides, it is commonly obtained in impure colored forms. BaS is quite poisonous, as are related sulfides, such as CaS, which evolve toxic hydrogen sulfide upon contact with water. BaS is an important precursor to other barium compounds including BaCO3 and the pigment lithopone, ZnS/BaSO4. Zinc sulfate is the inorganic compound with the formula ZnSO4 as well as any of three hydrates. It was historically known as “white vitriol”. It is a colorless solid that is a common source of soluble zinc ions. The hydrates, especially the heptahydrate, are the primary forms used commercially. The main application is as a coagulant in the production of rayon. It is also a precursor to the pigment lithopone. Zinc sulfate is used to supply zinc in animal feeds, fertilizers, and agricultural sprays. Zinc sulfate, like many zinc compounds, can be used to control moss growth on roofs. It is used as in electrolytes for zinc plating, as a mordant in dyeing, as a preservative for skins and leather and in medicine as an astringent and emetic. Zinc sulfate and barium sulfide solution by reacting to precipitate, filtering, drying and pulverizing, and then calcined at red heat, quench and poured into water, got the lithopone. Lithopone is a white pigment composed partly of this substance. Lithopone powder can be used for paint, but it is also used in the production of ink, plastic, and rubber. The use of lithopone is wider than ZnS. In the structure, lithopone(Cas No.1345-05-7) and zinc sulfide composition similar to, containing barium sulfate composition, poor durability. Powdering resistance is poor. Cheap price, therefore may partly replace titanium dioxide using. Under UV irradiation, ZnS fade to gray. To avoid this problem, nickel powder and iron was added in the preparation lithopone, first calcination cobalt and copper. Titanium dioxide stable properties, widely used as a white pigment in paints, it has good covering power, and at similar, but unlike the lead will be black; it has the same persistence zinc white. Titanium dioxide is also used as an enamel matting agents, can produce a very bright, hard and acid-proof enamel glaze surface. Now some lithopone using surface active agent for surface treatment, in order to improve its performance.
