Strontium sulfate

Strontium sulfate (SrSO4) is the sulfate salt of strontium. It is a white odorless, crystalline powder. It occurs in nature as the mineral celestine.

Chemical Properties
It is soluble in water to the extent of 1 part in 8,800. It is more soluble in dilute HCl and nitric acid and appreciably soluble in alkali chloride solutions (eg. sodium chloride).

Occurrence in Biology
Crystallized strontium sulfate is utilized by a small group of radiolarian protozoa, called the Acantharea, as a main constituent of their skeleton.

Uses
Like many strontium compounds, strontium sulfate will produce a bright red flame when burned. For this reason it is used in pyrotechnics. The primary difference is that because of the sulfate ion this compound can be used as a high-temperature oxidizer. Thus the oxidizing function will not activate till certain heat levels. These heat levels are commonly found in thermite mixtures, which are mixtures of a metallic fuel, usually magnesium or aluminum, and an oxidizer. It is also used in ceramics.

كبريتات سترونتيوم Sulfato de estrôncio