A process for the rectification of mixtures of high-boiling air- and / or temperature-sensitive substances which require high separation efficiency, in the medium vacuum, as well as suitable for this process columns

The invention concerns a process for extracting pure substances from mixtures of high-boiling air and/or temperature-sensitive substances which require a high separative power by rectification in a fine vacuum in columns containing metal cloth packing with an ordered structure and using channel liquid separators with 500 or more draining points/m . The draining points are arranged at an angle of 90 DEG to the cloth layers of the packing elements (7, 8) located immediately below the distributors. Two or a plurality of the packing elements (7, 8) below the liquid separator (6) have only a slight height which practically ensures the exclusion of air. These packing elements are shaped such that, during rectification, no heat can be exchanged through the column wall. The invention also concerns the packing columns used for this process and the use of this process and this column for the distillative fine-purification of vitamin E acetate.