Strontium forms 0.02-0.03% of the earth's crust and is present in igneous rocks in amounts averaging 375 ppm. Of the naturally occurring strontium compounds, only the minerals strontianite (strontium carbonate) and celestite (strontium sulfate) are of economic importance.
Strontium carbonate is a white or gray powder with the chemical formula of SrCO3, which is found in both industrial and mineral forms. This chemical compound is odorless and has a weak alkaline property due to the presence of carbonate in its structure, which leads to its high reactivity with acids.
Strontium carbonate is practically insoluble in water (1 part per 100,000), but if the water is saturated with CO2, the solubility of strontium carbonate increases dramatically (1 part per 1000). It should be noted that strontium carbonate is soluble in ammonium salts and dilute acids.
Strontium carbonate is synthesized by two methods. In the first method, strontium carbonate is generated from celestine ore with the chemical formula of SrSO4, which is naturally occurring, or it is generated by using soluble strontium salts and reacting it with a solution of carbonate salt (usually sodium or aluminum carbonate) or carbon dioxide gas, based on the following reaction:
Sr(NO3)2 (aq) + Na2CO3 (aq) → SrCO3 (s) + 2 NaNO3 (aq)
It should be noted that most of the celestine ore in nature is converted to strontium carbonate; because unlike the other strontium salts, carbonate salts are preferred because of its lower price and also because of that the carbonates are not hygroscopic materials. In the second method, a solution of strontium sulfide with carbon dioxide gas is used:
SrS (aq) + CO2 (g) → SrCO3 (s) + H2S (g)
Strontium Carbonate is the most widely used Strontium compound. Thanks to its versatility and non-hazardous nature, it is used in a diverse range of applications such as Electronics, Metallurgy, Chemicals, and Glass.
Strontium carbonate is an important material for the production of glass substrates for displays and photovoltaic panels. It is also used in cathode ray tube (CRT), such as a color television tube, to absorb electrons from the cathode.
Since strontium carbonate has only one crystalline phase, it has therefore been widely studied as a model system for bio-crystallization. Strontium carbonate has been shown to have an excellent performance in the low-temperature catalytic oxidation of VOC (volatile organic compound) and chemiluminescence sensors. In other words, strontium carbonate is used in the electronics industry.
It is also used in the manufacture of rainbow glass, luminescent dyes, strontium oxide, or strontium salts.
Strontium carbonate is widely used in the ceramic frits and glazes industry as an additive in the plating of ceramics.
In the zinc processing industry, the strontium carbonate is used for the purification of electrolytic zinc.
Strontium carbonate is used in the industry of manufacturing strontium ferrite and permanent magnets which is used in speakers, magnet doors, small DC motors, automotive electronic components, and household appliances.
Strontium carbonate is used to make superconductors such as BSCCO as well as to make electroluminescence materials.
Due to the nature of strontium carbonate, which is known as the weak base of Lewis, it can be used as a basic material to make other strontium compounds by reacting with the corresponding acid. For example, to produce strontium nitrate, strontium carbonate can be reacted with nitric acid to produce strontium nitrate.
Strontium carbonate is also used as a cheap coloring agent in fireworks and causes the red color in fireworks products.
Finally, this material is used to produce raw materials for the production of strontium metal and other strontium compounds.