Zero liquid discharge systems, processes, and techniques for treating a saltwater without evaporative crystallization. The saltwater is treated by a fluidic circuit comprising a high-pressure reverse osmosis (“HPRO”) unit configured to operate at a hydraulic pressure of at least 1,500 psi, a cooling crystallizer, and a solids-liquid separator. The saltwater is first concentrated by the HPRO unit to produce an HPRO brine, which is subsequently cooled to a designated crystallization temperature by the cooling crystallizer. The cooling crystallizer crystallizes salt crystals from the cooled HPRO brine and produces a salt-diminished brine. The solids-liquid separator separates the salt-diminished brine from the salt crystals. The salt-diminished brine from the solids-liquid separator is returned to the HPRO unit for further treatment, which allows additional salts to be crystallized from the returned salt-diminished brine.

A method for producing a concentrated aqueous sodium hydroxide solution from a purge stream deriving from a sodium carbonate, or sesquicarbonate, or wegsheiderite crystallizer, or sodium bicarbonate crystallizer, said purge stream comprising sodium carbonate and/or bicarbonate, and at least 1% of sodium chloride or sodium sulfate and a soluble impurity from an ore deposit comprising at least one of the following elements: As, Ba, B, Ca, Co, K, Li, Mo, P, Pb, Se, Sn, Sr, Te, Tl, Ti, V, and W, to be purified, the method comprising: causticizing at least 50 mol. % of the sodium carbonate into a caustic solution and into a calcium carbonate mud with lime and water; separating the mud from the caustic solution; concentrating the caustic solution by removing part of the water to obtain a concentrated caustic solution comprising at least 25% NaOH, and a crystallized solid comprising sodium carbonate and sodium chloride and/or sulfate; and separating the crystallized solid from the concentrated caustic solution, said crystallized solid to be disposed of or to be further valorized.

A method for producing a concentrated aqueous sodium hydroxide solution from a purge stream deriving from a sodium carbonate, or sesquicarbonate, or wegsheiderite crystallizer, or sodium bicarbonate crystallizer, said purge stream comprising sodium carbonate and/or bicarbonate, and at least 1% of sodium chloride or sodium sulfate and a soluble impurity from an ore deposit comprising at least one of the following elements: As, Ba, B, Ca, Co, K, Li, Mo, P, Pb, Se, Sn, Sr, Te, Tl, Ti, V, and W, to be purified, the method comprising: causticizing at least 50 mol. % of the sodium carbonate into a caustic solution and into a calcium carbonate mud with lime and water; separating the mud from the caustic solution; concentrating the caustic solution by removing part of the water to obtain a concentrated caustic solution comprising at least 25% NaOH, and a crystallized solid comprising sodium carbonate and sodium chloride and/or sulfate; and separating the crystallized solid from the concentrated caustic solution, said crystallized solid to be disposed of or to be further valorized.

A soda ash and sodium bicarbonate production method is provided, in which solution mining, pretreatment, stripping, concentration, sodium carbonate decahydrate crystallization, separation, dissolution, sodium carbonate monohydrate crystallization, separation and drying are performed to obtain dense soda ash. A dissolved sodium carbonate decahydrate solution or a concentrated brine 3 is subjected to crystallization, separation and drying to produce sodium bicarbonate. A discharge liquid 1 generated in the sodium carbonate decahydrate crystallization and separation is subjected to causticization and evaporation to recycle sodium carbonate. Causticized sludge generated in causticization is calcined and then recycled for causticization. The process provided herein maximizes the resource utilization.

A soda ash and sodium bicarbonate production method is provided, in which solution mining, pretreatment, stripping, concentration, sodium carbonate decahydrate crystallization, separation, dissolution, sodium carbonate monohydrate crystallization, separation and drying are performed to obtain dense soda ash. A dissolved sodium carbonate decahydrate solution or a concentrated brine 3 is subjected to crystallization, separation and drying to produce sodium bicarbonate. A discharge liquid 1 generated in the sodium carbonate decahydrate crystallization and separation is subjected to causticization and evaporation to recycle sodium carbonate. Causticized sludge generated in causticization is calcined and then recycled for causticization. The process provided herein maximizes the resource utilization.

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 cooling pond system and related methods of improving cooling performance in a cooling pond system using one or more submerged dams to increase cooling performance within the cooling pond system, and increase salt precipitation or recovery. The inclusion of one or more submerged dams within an existing cooling pond system can reduce an outflow temperature by 1-5° F. as compared to the same cooling pond system without any submerged dams. In addition or alternatively, pond depth can be controlled to enhance flow mixing and convection cooling. As the temperature is reduced throughout the cooling pond system, more potassium containing salts are precipitated form the brine solution resulting in increased production or recovery within the same cooling footprint.

A method of forming lithium carbonate from a lithium-bearing solution including:

evaporating the lithium-bearing solution to precipitate a first group of impurities;
removing the first group of impurities to form a first purified solution; and
performing a flash crystallisation step within a predetermined temperature range to crystallise a second group of impurities from the first purified solution;
removing the second group of impurities from the first solution to form a second purified solution, wherein at least 90 wt % of lithium is recovered from the first purified solution; and
reacting the second purified solution with a metal carbonate to form lithium carbonate of at least 90 wt % purity.

A method of forming lithium carbonate from a lithium-bearing solution including:

evaporating the lithium-bearing solution to precipitate a first group of impurities;
removing the first group of impurities to form a first purified solution; and
performing a flash crystallisation step within a predetermined temperature range to crystallise a second group of impurities from the first purified solution;
removing the second group of impurities from the first solution to form a second purified solution, wherein at least 90 wt % of lithium is recovered from the first purified solution; and
reacting the second purified solution with a metal carbonate to form lithium carbonate of at least 90 wt % purity.