Thorium is as chemical element which occurs naturally. It is radioactive in nature and has the atomic number of 90 and the chemical symbol Th. It was discovered in 1828 and named after Thor the Norse god of thunder. When it decaying it releases radon-22 gas as well as radium and actinium. Thorium is radioactive, but has a very slow rate of decay and the radiation it emits is not absorbed by the body, which means that it can safely be used for some important applications.
Uses of thorium
- One of the main uses of Thorium is in metal alloys such as Mag-Thor, an magnesium alloy that is used in aircraft engines and rockets. This is due to its ability to increase strength and creep resistance.
- Thorium is used in its gaseous form, thoria, in gas tungsten arch welding. It improves arch stability and strength.
- Thorium is used as a radiation shield and is very good in this application. However, lead or depleted uranium are more commonly used in this application.
- Thorium has also been used to carbon date fossils, seabeds and mountain ranges.
- Thorium dioxide is used as a material in heat-resistant ceramics, especially those used to create crucibles.
- It is also added to glass to improve refractive index and decrease dispersion. This type of glass is used in camera lenses and scientific equipment. The glass can become yellow over time, but can be returned to its clear state by exposing it to high levels of UV light. There is minimal health risks to using lenses created with thorium dioxide.
- Thorium fluoride is also used as an antireflection material in optical coatings.
- Thorium dioxide is also used to control the grain size of tungsten which is used to create the metal spirals for electric lamps.
- Trace amounts of thorium are used in the filaments of magnetron tubes used to generate microwave frequencies. These are used in microwave ovens and radars.
- It is used as catalyst agent in the conversion of ammonia to nitric acid in petroleum cracking and when producing sulfuric acid.
- Thorium is being researched as a substitute for uranium in nuclear reactors due to the fact that much more of this material is available and it is much more difficult to use this substance in weaponry. The waste produced when using thorium is also less than that of uranium.
- In the past thorium was also used in the mantles of gas lights to produce intense white light as well as carbon arc lamps. It was also used as the main ingredient Thorotrast, a component of x-ray diagnosis.