Patent GB-217598-A (GB)
Title: Improvements in or relating to the treatment of natural alkaline salts
IPC: C01D7/18
Filed: 1924-06-12
Abstract: Solutions of natural salts comprising substantial amounts of sodium carbonate are treated with ammonia and carbon dioxide or with ammonium bicarbonate preferably at 28 DEG  B<\>ae to precipitate sodium bicarbonate which is filtered off at the temperature of maximum solubility of one of the other salts, such as 33 DEG  C.  The Specification as open to inspection under Sect. 91 (3) (a) comprises also treating natural waters from Mexico containing sodium chloride, sulphate, sesquicarbonate and bicarbonate at 28 DEG  B<\>ae with carbonic acid alone to obtain precipitated sodium bicarbonate, which is freed from sulphate by bringing the suspension to 33.3 DEG  C.  Or the natural solution, which may be at 52 DEG  C. in the sun, is cooled to 33.3 DEG  C. and stirred without any addition, when bicarbonate or sequicarbonate separates.  The sylvenite potash deposits of Alsace, containing sodium and potassium chlorides, are treated by the ammonia-soda process to obtain sodium bicarbonate and a residual liquor containing potassium and ammonium chlorides, which may be evaporated to obtain the mixed salts for use as a manure. Stassfurt salts and the salts extracted from sea algae may be treated similarly. Chili sodium nitrate liquor of 38 DEG  B<\>ae is treated with ammonia and carbonic acid at 33 DEG  C. or more and at normal or increased pressure to obtain sodium bicarbonate and ammonium nitrate. It is stated that it has been proposed to make potassium bicarbonate from potassium chloride by a modified ammonia process in which the ammonia is replaced by trimethylaniline.  This subject-matter does not appear in the Specification as accepted.ALSO:Solutions of natural salts comprising substantial amounts of sodium carbonate are treated with ammonia and carbon dioxide or with ammonium bicarbonate preferably at 28 DEG  B<\>ae. to precipitate sodium bicarbonate, which is filtered off at the temperature of maximum solubility of one of the other salts, such as 33 DEG  C.  The Specification as open to inspection under Sect. 91 (3) (a) comprises also treating natural waters from Mexico containing sodium chloride, sulphate, sesquicarbonate, and bicarbonate at 28 DEG  B<\>ae. with carbonic acid alone to obtain precipitated sodium bicarbonate, which is freed from sulphate by bringing the suspension to 33.3 DEG  C.  Or the natural solution, which may be at 52 DEG  C. in the sun, is cooled to 33.3 DEG  C. and stirred without any addition, when bicarbonate or sesquicarbonate separates.  The sylvenite potash deposits of Alsace, containing sodium and potassium chlorides, are treated by the ammonia-soda process to obtain sodium bicarbonate and a residual liquor containing potassium and ammonium chlorides, which may be evaporated to obtain the mixed salts for use as a manure.  Stassfurt salts and the salts extracted from sea algae may be treated similarly. Chili sodium nitrate liquor of 38 DEG  B<\>ae. is treated with ammonia and carbonic acid at 33 DEG  C. or more and at normal or increased pressure to obtain sodium bicarbonate and ammonium nitrate. It is stated that it has been proposed to make potassium bicarbonate from potassium chloride by a modified ammonia-soda process in which the ammonia is replaced by trimethylaniline.  This subject-matter does not appear in the Specification as accepted.