Ambient air is the only practical source of krypton and xenon. Krypton-xenon concentrate is received at large-scale air separation units as a byproduct of oxygen and nitrogen production. Purification of noble gases out of concentrate is a multi-step process. Enrichment, separation into components, and purification of krypton and xenon are performed in consecutive stages on several production units comprising a unified technological chain.
Low heat conductivity and high density are unique thermodynamic properties of krypton and xenon.
| Krypton at 99.999% purity | Kr | Concentration, ppm |
| Hydrogen | H2 | 0.5 |
| Nitrogen | N2 | 2.0 |
| Oxygen | O2 | 0.5 |
| Argon | Ar | 0.1 |
| Xenon | Xe | 1.0 |
| Carbon Oxides | CO+CO2 | 0.5 |
| Humidity | H2O | 1.0 |
| Hydrocarbons | CnHm | 0.5 |
| Fluorides | CF4+C2F6+SF6 | 0.5 |