Barium sulfate 98% (100g)

Barium sulfate 98% (100g)

Barium sulfate (or sulphate) is the inorganic compound with the chemical formula BaSO₄. It is a white crystalline solid that is odorless and insoluble in water. It occurs as the mineral barite, which is the main commercial source of barium and materials prepared from it. The white opaque appearance and its high density are exploited in its main applications.

Properties

Chemical formula : BaSO₄

Molar mass: 233.38 g/mol

Appearance: white crystalline

Density: 4.49 g/cm³

Melting point: 1,580 °C (2,880 °F; 1,850 K)

Boiling point: 1,600 °C (2,910 °F; 1,870 K) (decomposes)

Solubility: insoluble in alcohol, soluble in concentrated, hot sulfuric acid

Uses

About 80% of the world’s barium sulfate production, mostly purified mineral, is consumed as a component of oil well drilling fluid. It increases the density of the fluid, increasing the hydrostatic pressure in the well and reducing the chance of a blowout.

Safety aspects

Although soluble salts of barium are moderately toxic to humans, barium sulfate is nontoxic due to its insolubility. The most common means of inadvertent barium poisoning arises from the consumption of soluble barium salts mislabeled as BaSO₄. In the Celobar incident (Brazil, 2003), nine patients died from improperly prepared radiocontrast agent. In regards to occupational exposures, the Occupational Safety and Health Administration set a permissible exposure limit at 15 mg/m³, while the National Institute for Occupational Safety and Health has a recommended exposure limit at 10 mg/m³. For respiratory exposures, both agencies have set an occupational exposure limit at 5 mg/m³.

History

Barium sulfate is reduced to barium sulfide by carbon. The accidental discovery of this conversion many centuries ago led to the discovery of the first synthetic phosphor. The sulfide, unlike the sulfate, is water-soluble.

During the early part of the 20th century, during the Japanese colonization period, hokutolite was found to exist naturally in the Beitou hot-springs area near Taipei City, Taiwan. Hokutolite is a radioactive mineral composed mostly of PbSO₄ and BaSO₄, but also containing traces of uranium, thorium and radium. The Japanese harvested these elements for industrial uses, and also developed dozens of “therapeutic hot-spring baths” in the area.