Process for producing sodium carbonate and/or sodium bicarbonate from an ore mineral comprising sodium bicarbonate

Abstract

In a process to produce sodium carbonate and/or sodium bicarbonate from an ore mineral comprising sodium bicarbonate, a production solution comprising sodium carbonate is introduced into less basic compartments of an electrodialyser comprising alternating less basic and more basic adjacent compartments separated from each other by cationic membranes, the more basic compartments being delimited by anionic faces of bipolar membranes on one side and by the cationic membranes on the other side; a solution comprising sodium hydroxide is produced into the more basic compartments by combination of sodium ions flux crossing the cationic membrane and hydroxyl ions flux crossing the anionic face of the bipolar membranes, and is then extracted from the electrodialyser to be used as a reaction solution; the reaction solution is put into contact with the mineral ore to form a solution comprising sodium carbonate; and the solution comprising sodium carbonate is divided into a part used as the production solution and a remaining part used as a produced solution.

1 . A process to produce sodium carbonate and/or sodium bicarbonate from an ore mineral comprising sodium bicarbonate, comprising:
 introducing a production solution comprising sodium carbonate into less basic compartments of an electrodialyser comprising alternating less basic and more basic adjacent compartments separated from each other by cationic membranes, the more basic compartments being delimited by anionic faces of bipolar membranes on one side and by the cationic membranes on the other side;   optionally extracting a solution comprising sodium bicarbonate from the less basic compartments;   producing a solution comprising sodium hydroxide into the more basic compartments, by combination of flux of sodium ions crossing the cationic membrane and flux of hydroxyl ions crossing the anionic face of the bipolar membranes;   extracting the solution comprising sodium hydroxide from the more basic compartments of the electrodialyser and using such solution to constitute a reaction solution;   putting the reaction solution into contact with the mineral ore comprising sodium bicarbonate in order to form a solution comprising sodium carbonate; and   dividing the solution comprising sodium carbonate into a part which is used to constitute said production solution and a remaining part which constitutes a produced solution.   
     
     
         2 . The process according to  claim 1 , wherein the produced solution is evaporated in order to produce a suspension comprising sodium carbonate crystals, which are separated and valorized. 
     
     
         3 . The process according to  claim 1 , wherein a solution comprising sodium bicarbonate is extracted from the less basic compartments of the electrodialyser, this sodium bicarbonate-comprising solution being afterwards cooled in order to produce a suspension comprising sodium bicarbonate crystals, and the suspension being separated into valorized sodium bicarbonate crystals and a sodium bicarbonate mother liquor. 
     
     
         4 . The process according to  claim 3 , wherein the sodium bicarbonate mother liquor is debicarbonated and introduced into the less basic compartments of the electrodialyser 
     
     
         5 . The process according to  claim 3 , wherein the sodium bicarbonate mother liquor is debicarbonated and introduced into the more basic compartments of the electrodialyser. 
     
     
         6 . The process according to  claim 3 , wherein the sodium bicarbonate mother liquor is introduced into the less basic compartments of another electrodialyser. 
     
     
         7 . The process according to  claim 6 , wherein the concentration in sodium carbonate of the sodium bicarbonate mother liquor is sufficiently low so as to generate CO 2  gas into the less basic compartments of the other electrodialyser. 
     
     
         8 . The process according to  claim 7 , wherein the generated CO 2  is put into contact with at least part of the produced solution comprising sodium carbonate, in order to produce sodium bicarbonate crystals. 
     
     
         9 . The process according to  claim 1 , wherein part of the reaction solution comprising sodium hydroxide is mixed with a solution comprising sodium bicarbonate, in order to convert at least part of the sodium bicarbonate into sodium carbonate. 
     
     
         10 . The process according to  claim 1 , wherein the mineral ore comprising sodium bicarbonate is an underground trona or nahcolite ore mineral.