How is helium separated from other elements and other materials around it?

Answer 1

Helium can be separated from other gasses in a mixture by at least 2 known methods.

By pressurising the helium, regulating tyhe pressure and directing it through a sealed semi-permeable membrane in a pressure housing.The helium molecule being smaller than any of the others (with the sole exeption of Hydrogen, passes through the membrane faster than other gas molecules,and is saved and pumped into storage,while the other gasses are vented off and dumped. The proportion dump gas,which contains some helium can be varied by altering a fine needle valve (variable orifice) .It is a trade off between purity and efficiency. this method reduces the "contaminants" in a helium mix,but does not totally seperate the mixture.This was first marketed for use in diving systems by GDS then Gas Services.

2. By passing it through an absorbent e.g. Molecular Sieve, such as in the "Kinergentics Inc" pressure swing system built in the 1980's

3. It's also possible to use cryogenics to freeze out the different gasses at their various temperatures.