The present invention pertains to the field of cryogenics and more precisely relates to low-temperature air rectification techniques for condensing and separating inert gases, mainly xenon. This method for producing a xenon concentrate is carried out in air separation devices where the air is separated in a lower column and in an upper column. A flow of gaseous nitrogen is supplied from the lower column to a main condenser unit and the condensed flow of liquid nitrogen is further fed from the main condenser unit to the lower column. A main flow of liquid oxygen is derived from the upper column and supplied to the main condenser unit in order to be partially vaporised. A portion of the main flow of liquid oxygen is extracted from the main condenser unit in the shape of a circulating liquid-oxygen flow, a portion of this circulating liquid-oxygen flow being then supplied to a vaporiser-condenser where it is partially vaporised. It is thus possible to obtain a flow of purified gaseous oxygen as well as an oxygen flow for discharging the explosive impurities out of the air separation device. The xenon concentrate is extracted from the oxygen flow used for discharging the explosive impurities out of the air separation device, wherein said extraction is preferably carried out according to an adsorption method.
