Barium sulfate

Uses

Radiocontrast agent

Barium sulfate is frequently used clinically as a radiocontrast agent for Barium meal'.

It is administered, orally or by atomic number (Z = 56) of barium, its compounds absorb X-rays more strongly than compounds derived from lighter nuclei.

Pigment

Barium sulfate mixtures are used as white pigment for paints. The combination of barium sulfate and zinc sulfide (ZnS) is called lithopone. Barium sulfate itself is called white lead due to the latter's toxicity.

Pyrotechnics

Barium sulfate is also used as a high temperature oxidizer in certain pyrotechnic formulas, as bariums compounds emit a green colored light when burned. Barium nitrate is more common in green pyrotechnic formulas, as it contains an oxidizer while still producing green colored light.

Other uses

Barium sulfate is used as a filler in plastics and as a component of oil well drilling fluid to increase the density.

It is used in brake linings, acoustic foams and powder coatings

Barium sulfate is also used during the procedure of the soil pH test. In this test it is used so that it precipitates out any particles (usually clay particles) which would otherwise 'cloud' solution preventing one from seeing the colour of the pH indicator i.e. the result of the test.

It is used in root canal filling.

In colorimetry barium sulphate is used as a near-perfect diffuser when measuring light sources.

History

Barium sulfate is reduced to phosphor (Hollman and Wiberg, 2001). The sulfide, unlike the sulfate, is water soluble.

References

• Holleman, A. F. and Wiberg, E. (2001) Inorganic Chemistry, San Diego, CA : Academic Press, ISBN 0-12-352651-5