Isolation of Noble Gases from Liquid Air

Atmospheric air is the only source for the gases neon, argon, krypton and xenon. Helium is found in atmospheric air, natural gas and radioactive minerals. 

Fractination of liquid air by Claude process give rise to two main fractions, one containing mainly nitrogen and the other containing mainly oxygen. 

The liquid part of oxygen fraction (lA) contaiiung Kr, Xe and oxygen accumulate at the bottom of the left column. The oxygen is evaporated by the heat of compressed air while krypton and xenon in the liquid state. The two can be separated by fractional distillation or by selective adsorption on charcoal. 

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