PROCESS FOR RECOVERING SODA VALUES FROM UNDERGROUND SODA DEPOSITS

摘要

Process for recovering soda values from a first and a second soda deposit situated respectively in a first underground cavity (A) and a second underground cavity (Α') containing respectively a first soda solution (1) and a second soda solution (1'), the second soda solution (1') containing a higher concentration in sodium chloride and/or sodium sulfate than the first soda solution (1), the process comprising: • extracting a stream of first soda solution (1) from the first cavity (A); • introducing the stream of first soda solution (1) in a first process (B) which produces, out of the soda solution, first soda crystals (3) on one hand and a first waste purge stream (2) containing a higher concentration in sodium chloride and/or in sodium sulfate than the first soda solution (1), on the other hand; • introducing at least part (2b) of the first waste purge stream (2) in the second cavity (A'); • extracting a stream of second soda solution (1') from the second cavity (Α'); introducing the stream of second soda solution (1') in a second process (Β') which produces, out of the soda solution, second soda crystals (3') which have a higher concentration in sodium chloride and/or sodium sulfate than the first soda crystals (3).