Process for the recovery of argon

Abstract From the Canadian patent

There is disclosed an improved process for recovering argon from a tail gas stream, preferably a tail gas obtained from a hydrogen recovery unit processing a purge gas obtained in the synthesis of ammonia and comprised of argon, methane, nitrogen, and residual quantities of hydrogen, wherein the tail gas is partially liquefied prior to introduction into a first fractionation column to form a bottoms liquid stream comprised of argon and methane wherein such liquid stream is thereupon introduced into a second fractionation column to separate argon as an overhead gaseous stream which is condensed to form liquid argon or as product.