Argon (Ar) is a colourless, odourless, non-reactive, inert gas. In high concentrations, it has an asphyxiating effect. As argon is an atmospheric gas (0.93% vol.), it is generally sourced by separating air. A crude argon stream containing up to 5% oxygen is removed from the main air separation column and purified to produce the commercial purity grade required. Argon can also be recovered from the exhaust streams of certain ammonia plants.
Industrial applications
Argon has many different applications in many industries. The most common one is as a shielding gas for arc welding – either in pure form or as part of various mixtures. It is one of the main gases used in filling mixtures for incandescent (filament) lamps, phosphorescent tubes and thyratron radio tubes