Patent GB-736459-A (GB)
Title: Improvements relating to the concentration of isotopes
IPC: B01D59/32
Filed: 1953-06-16
Abstract: A compound A is separated into two fractions which are relatively enriched in different isotopes of an element contained in A, by forming a complex compound AB, heating the complex compound to form a vapour phase in which the ratio between the content of the compound A in the form of the complex to the total content of the compound A is different from that in the liquid phase, and creating a countercurrent flow between the vapour phase and the liquid phase in a cascade to effect an isotope exchange between the vapour phase and the liquid phase so that lighter isotopes are concentrated at one end of the cascade and heavy isotopes at the other.  In examples (1) the complex of diethyl (or dimethyl) ether and boron trifluoride was distilled at 75 DEG  C. in a column of 30 theoretical plates at a pressure of 60 mm. Hg. B10 became concentrated at the bottom of the column; (2) trimethyl amine and acetic acid were distilled at 80 DEG C. and 40 mm. Hg. N15 became concentrated at the bottom of the column. The distillation was carried out with total reflux and a boil up of about 1 g. per minute for 24 hours, using about 50 g. material. The distillation of the complex of boron trifluoride and anisole, the anisole being recirculated from bottom to top of the column, and of the complex of triethylamine and sulphur dioxide (for separation of the sulphur isotopes) are also referred to.ALSO:A compound A is separated into two fractions which are relatively enriched in different isotopes of an element contained in A, by forming a complex compound AB and converting the complex compound, if necessary, to the liquid state by solution or heat, heating the complex compound to form a vapour phase in which the ratio between the content of the compound A in the form of the complex to the total content of the compound A is different from that in the liquid phase, and creating a countercurrent flow between the vapour phase and the liquid phase in a cascade to effect an isotope exchange between the vapour phase and the liquid p  phase so that lighter isotopes are concentrated at one end of the cascade and heavy isotopes at the other.  In examples: (1) the complex of diethyl (or dimethyl) ether and boron trifluoride was distilled at 75 DEG  C. in a column of 30 theoretical plates at a pressure of 60 mm. Hg. B10 became concentrated at the bottom of the column.  (2) Trimethylamine and acetic acid were distilled at 80 DEG C. and 40 mm. Hg.  N15 became concentrated at the bottom of the column.  The distillation was carried with total reflux and a boil-up rate of about 1 g. per minute for 24 hours using about 50 g. material.  Other examples referred to are the complex of boron trifluoride and anisole, the anisole being recirculated from bottom to top of the column, ammonia, carbon dioxide and water, the water being recirculated, ammonia, sodium hydrogen and sodium dihydrogen phosphate, the water and phosphates in solution being recirculated, the complex of triethylamine and sulphur dioxide, and sulphur dioxide, phosphoric acid and sodium dihydrogen phosphate.  In the last two cases the sulphur isotopes are separated.