The pure metal is used as a “getter” in vacuum tubes and isintroduced to lead bearing metals via electrolysis to harden thelead. However the most extensive use of barium is in the form of itscompounds of which the most important are the peroxide(BaO2), chloride (BaCl2), sulphate(BaSO4), carbonate (BaCO3), nitrate(Ba(NO3)2), chlorate(Ba(ClO3)2.H2O), and hydride(BaH2). · The sulphate is used in pigments and glassmaking, and the insolublenon-toxic form is used in radiography. · The carbonate is used as a rat poison. · The nitrate and chlorate produce colours in pyrotechnics. · Impure sulphide phosphoresces upon exposure to light. · Barium heat-treated to 200°C (392°F) in a hydrogen gas it formsbarium hydride (BaH2), a grey powder that decomposes oncontact with water and can be used as a source of nascent hydrogenfor life rafts. · Barium is also a key element in the production of ceramicsuperconductors. |