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Strontium

Strontium

The word ‘Strontium’ has obtained a well earned bad press as regards the general public due to emissions of the isotope Strontium-90 caused by above ground nuclear explosions between 1945 and 1963.

Strontium metal, as produced from strontianite and celestine(SrSO4), has many safe industrial uses. The largest use by volume is in the form of carbonate, where it is processed further into glasses used to create the colour red for cathode ray television screens. It is also used to obtain the brilliant red in fireworks and warning flares.

Lipmann Walton is concerned with the fraction of Strontium units which are processed through to Sr 99% min metal. The main source of free market traded metal is China from where we obtain our supply. The main use of Strontium is in alloys of Aluminium and Magnesium, where amounts of less than 10% are used to provide corrosion and creep resistance in die-cast products.

The largest user of such products is the automotive industry. On the photos you will see examples of hermetically sealed packing, which is used to prevent the Strontium reacting with the atmosphere. Strontium metal is usually transported as dangerous goods.

Strontium FACTS
Strontium was recognised as an element in 1790 by A. Crawford in Edinburgh, Scotland and was isolated in 1808 by Sir Humphry Davy, by using electrolysis in London, England.

It is a silvery-white, relatively soft metal that is obtained by heating strontium oxide (SrO) with aluminium metal. The bulk metal is protected by an oxide film, but finely powdered strontium metal will spontaneously ignite in air or if in contact with water.

Due to its extreme reactivity to air, this element always naturally occurs combined with other elements and compounds, as in the minerals strontianite, celestine, etc. It is isolated as a yellowish metal and is somewhat malleable.

Strontium commonly occurs in nature, averaging 0.034% of all igneous rock and is found chiefly as the form of the sulfate mineral celestite (SrSO4) and the carbonate strontianite (SrCO3). Of the two, celestite occurs much more frequently in sedimentary deposits of sufficient size to make development of mining facilities attractive.

Volatile strontium salts impart a beautiful crimson color to flames, and these salts are used in pyrotechnics and in the production of flares. Natural strontium is a mixture of four stable isotopes.

Today, the primary use for strontium is in glass for colour television cathode ray tubes. It also has other commercial uses such as in the production of ferrite magnets and refining zinc.

Atomic no.
Relative atomic mass
Melting point
Boiling point
Density
Electrical resistivity
Young’s modulus
Heat capacity
Abundance
Thermal conductivity
38
87.62
777 oC
1377 oC
2640 Kgm-3
130 nΩm
15.7 GPa
26.4 J/K/mol
360 ppm
35.3 W/m/K