A method for preparing particles of alkali metal bicarbonate by crystallization from a solution of alkali metal carbonate and/or bicarbonate in the presence of an additive in the solution, selected from the sulfates, sulfonates, the polysulfonates, the mines, the hydroxysultaines, the polycarboxylates, the polysaccharides, the polyethers and the etherphenols, alkali metal hexametaphosphate, the phosphates such as the organophosphates or the phosphonates, the sulfosuccinates, the amido-sulfonates, the aminosulfonates, preferably selected from: the phosphates, the organophosphates or the phosphonates, and such that the additive is present in the solution at a concentration of at least 1 ppm and preferably of at most 200 ppm.

A method for preparing particles of alkali metal bicarbonate by crystallization from a solution of alkali metal carbonate and/or bicarbonate in the presence of an additive in the solution, selected from the sulfates, sulfonates, the polysulfonates, the mines, the hydroxysultaines, the polycarboxylates, the polysaccharides, the polyethers and the etherphenols, alkali metal hexametaphosphate, the phosphates such as the organophosphates or the phosphonates, the sulfosuccinates, the amido-sulfonates, the aminosulfonates, preferably selected from: the phosphates, the organophosphates or the phosphonates, and such that the additive is present in the solution at a concentration of at least 1 ppm and preferably of at most 200 ppm.

A method for preparing alkali metal bicarbonate particles by crystallization from an alkali metal carbonate and/or bicarbonate solution with an additive present in the solution, chosen from among sulfates, sulfonates, polysulfonates, amines, hydroysultaines, polycarboxylates, polysaccharides, polyethers and ether-phenols, alkali metal hexametaphosphate, phosphates, sulfosuccinates, amidosulfonates, amine sulfonates, preferably chosen from among polysaccharides, and such that the additive is present in the solution at a concentration of at least 1 ppm and preferably at most 200 ppm.

A method for preparing alkali metal bicarbonate particles by crystallization from an alkali metal carbonate and/or bicarbonate solution with an additive present in the solution, chosen from among sulfates, sulfonates, polysulfonates, amines, hydroysultaines, polycarboxylates, polysaccharides, polyethers and ether-phenols, alkali metal hexametaphosphate, phosphates, sulfosuccinates, amidosulfonates, amine sulfonates, preferably chosen from among polysaccharides, and such that the additive is present in the solution at a concentration of at least 1 ppm and preferably at most 200 ppm.

A process for producing crystalline sodium bicarbonate, comprising: providing an aqueous sodium-bicarbonate containing liquor originating from a reactive crystallization step in which first sodium bicarbonate crystals are produced and recovered; feeding at least a portion of said aqueous sodium-bicarbonate containing liquor to a cooling crystallization unit to form second sodium bicarbonate crystals and produce a crystals slurry comprising the second sodium bicarbonate crystals; and withdrawing a portion of the crystals slurry from the cooling crystallization unit for the withdrawn second sodium bicarbonate crystals to be further processed. A portion of the second sodium bicarbonate crystals withdrawn from the cooling crystallization unit may be fed to a sodium bicarbonate reactive crystallization unit, to a caustic unit, or may be separated and dried. The reactive crystallization, separation and/or drying units where the second sodium bicarbonate crystals are further processed may be the same units where the first sodium bicarbonate crystals are processed.

A process for producing crystalline sodium bicarbonate, comprising: providing an aqueous sodium-bicarbonate containing liquor originating from a reactive crystallization step in which first sodium bicarbonate crystals are produced and recovered; feeding at least a portion of said aqueous sodium-bicarbonate containing liquor to a cooling crystallization unit to form second sodium bicarbonate crystals and produce a crystals slurry comprising the second sodium bicarbonate crystals; and withdrawing a portion of the crystals slurry from the cooling crystallization unit for the withdrawn second sodium bicarbonate crystals to be further processed. A portion of the second sodium bicarbonate crystals withdrawn from the cooling crystallization unit may be fed to a sodium bicarbonate reactive crystallization unit, to a caustic unit, or may be separated and dried. The reactive crystallization, separation and/or drying units where the second sodium bicarbonate crystals are further processed may be the same units where the first sodium bicarbonate crystals are processed.

A method for preparing particles of alkali metal bicarbonate by crystallization from a solution of alkali metal carbonate and/or bicarbonate in the presence of an additive in the solution, selected from the sulfates, sulfonates, the polysulfonates, the amines, the hydroxysultaines, the polycarboxylates, the polysaccharides, the polyethers and the ether-phenols, alkali metal hexametaphosphate, the phosphates, the sulfosuccinates, the amidosulfonates, the aminosulfonates, preferably selected from the polycarboxylates having a mean molecular weight lower than 8000 g/mol, and such that the additive is present in the solution at a concentration of at least 1 ppm and preferably of at most 200 ppm.

A method for preparing particles of alkali metal bicarbonate by crystallization from a solution of alkali metal carbonate and/or bicarbonate in the presence of an additive in the solution, selected from the sulfates, sulfonates, the polysulfonates, the amines, the hydroxysultaines, the polycarboxylates, the polysaccharides, the polyethers and the ether-phenols, alkali metal hexametaphosphate, the phosphates, the sulfosuccinates, the amidosulfonates, the aminosulfonates, preferably selected from the polycarboxylates having a mean molecular weight lower than 8000 g/mol, and such that the additive is present in the solution at a concentration of at least 1 ppm and preferably of at most 200 ppm.

Process for producing sodium carbonate and sodium bicarbonate in a continuous mode out of trona comprising: c) feeding crushed trona, an extraction water and an additive in a first leaching tank containing a dissolution solution comprising sodium carbonate and sodium bicarbonate, wherein the additive is selected from the group consisting of: anionic hexametaphosphate, anionic polyphosphate, anionic polyphosphonate, soja lecithine, anionic polycarboxylate polymer, anionic polyacrylate polymer, anionic polyacrylate-polyacrylamide co-polymer, anionic hydrolyzed polymaleic polymers, anionic maleic-acrylic acids copolymers, anionic acrylic acid-phosphonic acid copolymers and combinations thereof; d) dissolving at least partially the crushed trona in the dissolution solution in order to produce a first suspension; e) removing continuously the first suspension from the first leaching tank and feeding it with an additive into a second leaching tank wherein the additive is selected from the same group of additives of step c); f) dissolving at least partially the remaining crushed trona from step d) in the second leaching tank in order to produce a second suspension; g) separating the second solid particles from the second solution to produce a production solution comprising sodium carbonate and to produce a production solid comprising the second solid particles comprising sodium bicarbonate.

Process for producing sodium carbonate and sodium bicarbonate in a continuous mode out of trona comprising: c) feeding crushed trona, an extraction water and an additive in a first leaching tank containing a dissolution solution comprising sodium carbonate and sodium bicarbonate, wherein the additive is selected from the group consisting of: anionic hexametaphosphate, anionic polyphosphate, anionic polyphosphonate, soja lecithine, anionic polycarboxylate polymer, anionic polyacrylate polymer, anionic polyacrylate-polyacrylamide co-polymer, anionic hydrolyzed polymaleic polymers, anionic maleic-acrylic acids copolymers, anionic acrylic acid-phosphonic acid copolymers and combinations thereof; d) dissolving at least partially the crushed trona in the dissolution solution in order to produce a first suspension; e) removing continuously the first suspension from the first leaching tank and feeding it with an additive into a second leaching tank wherein the additive is selected from the same group of additives of step c); f) dissolving at least partially the remaining crushed trona from step d) in the second leaching tank in order to produce a second suspension; g) separating the second solid particles from the second solution to produce a production solution comprising sodium carbonate and to produce a production solid comprising the second solid particles comprising sodium bicarbonate.