Process for recovering soda values from underground soda deposits

摘要

Process for recovering soda values from first and second soda deposits situated respectively in first and second underground cavities containing respectively first and second soda solutions, the second soda solution containing a higher concentration in sodium chloride and/or sodium sulfate than the first soda solution, the process comprising: extracting a stream of first soda solution from the first cavity; introducing the stream of first soda solution in a first process which produces first soda crystals and a first waste purge stream containing a higher concentration in sodium chloride and/or in sodium sulfate than the first soda solution; introducing at least part of the first waste purge stream in the second cavity; extracting a stream of second soda solution from the second cavity; and introducing the stream of second soda solution in a second process which produces second soda crystals which have a higher concentration in sodium chloride and/or sodium sulfate than the first soda crystals.