Barium carbonate

Barium carbonate is the inorganic compound with the formula BaCO₃. Like most alkaline earth metal carbonates, it is a white salt that is poorly soluble in water. It occurs as the mineral known as witherite. In a commercial sense, it is one of the most important barium compounds.<ref name=Ull>Template:Ullmann</ref>

Preparation

Barium carbonate is made commercially from barium sulfide by treatment with sodium carbonate at Template:Convert (soda ash method) or, more commonly carbon dioxide at Template:Convert:<ref name=Ull/>

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Reactions

Barium carbonate reacts with acids such as hydrochloric acid to form soluble barium salts, such as barium chloride:

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Pyrolysis of barium carbonate gives barium oxide.<ref name=Brauer>Template:Cite book</ref>

Uses

Barium carbonate is mainly used to remove sulfate impurities from feedstock of the chlor-alkali process. Otherwise it is a common precursor to barium-containing compounds such as ferrites.<ref name=Ull/>

Other uses

Template:More citations needed section Barium carbonate is widely used in the ceramics industry as an ingredient in glazes. It acts as a flux, a matting and crystallizing agent and combines with certain colouring oxides to produce unique colours not easily attainable by other means. Its use is somewhat controversial since it can leach from glazes into food and drink. To reduce toxicity concerns, it is often substituted with strontium carbonate, which behaves in a similar way in glazes but is of lower toxicity.<ref>Template:Cite web</ref>

In the brick, tile, earthenware and pottery industries barium carbonate is added to clays to precipitate soluble salts (calcium sulfate and magnesium sulfate) that cause efflorescence.

It is sometimes used as an "energiser" in the Case-hardening process.