Applications
Thorium is a component of the magnesium alloy series, called Mag-Thor, used in aircraft engines and rockets and imparting high strength and creep resistance at elevated temperatures. Thoriated magnesium was used to build the CIM-10 Bomarc missile, although concerns about radioactivity have resulted in several missiles being removed from public display.
Thorium is also used in its oxide form (thoria) in gas tungsten arc welding (GTAW) to increase the high-temperature strength of tungsten electrodes and improve arc stability. The electrodes labeled EWTH-1 contain 1% thoria, while the EWTH-2 contain 2%. In electronic equipment, thorium coating of tungsten wire improves the electron emission of heated cathodes.
Thorium is a very effective radiation shield, although it has not been used for this purpose as much as lead or depleted uranium. Uranium-thorium age dating has been used to date hominid fossils, seabeds, and mountain ranges.
Environmental concerns related to radioactivity led to a sharp decrease in demand for nonnuclear uses of thorium in the 2000s.
Read more about this topic: Thorium Compounds