A method for producing a concentrated aqueous sodium hydroxide solution from a purge stream deriving from a sodium carbonate, or sesqui-carbonate, 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 sesqui-carbonate, 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.

Lithium recycling from expended Li-Ion batteries occurs thought selective recovery of lithium charge materials from a recycling stream including transition metals used for the charge material. Li recovery performed using an organic acid-based approach including terephthalic acid (TPA), benzenetetracarboxylic acid (BTCA), and other organic acids results in highly selective lithium extraction, achieving minimal transition metal contamination in the extracted solution. A recycling stream including cathode materials from spent/end-of-life Li-ion batteries provides a source for recycled Li, as well as other cathode material metals. Combining the organic acid in a hydrothermal reactor followed by filtration separates transition metal oxides from a lithium salt solution. The lithium salt may be recrystallized by acetone and dried to a powder consistency. Lithium carbonate is then recovered by sintering, and further filtered for recovering battery grade recycled Li.

Lithium recycling from expended Li-Ion batteries occurs thought selective recovery of lithium charge materials from a recycling stream including transition metals used for the charge material. Li recovery performed using an organic acid-based approach including terephthalic acid (TPA), benzenetetracarboxylic acid (BTCA), and other organic acids results in highly selective lithium extraction, achieving minimal transition metal contamination in the extracted solution. A recycling stream including cathode materials from spent/end-of-life Li-ion batteries provides a source for recycled Li, as well as other cathode material metals. Combining the organic acid in a hydrothermal reactor followed by filtration separates transition metal oxides from a lithium salt solution. The lithium salt may be recrystallized by acetone and dried to a powder consistency. Lithium carbonate is then recovered by sintering, and further filtered for recovering battery grade recycled Li.

A multi-pond system and method is disclosed for separating sodium carbonate from sodium chloride in process purge streams from soda ash production or similar facilities. The system comprises a first pond, exposed to atmospheric environment, for receiving the process purge stream and allowing deposition of sodium carbonate in accord with phase chemistry as water is evaporated and temperatures change thereby creating a liquor with increased sodium chloride concentration. A second pond for receiving the first pond liquor, exposed to the atmospheric environment, and allowing deposition of sodium chloride in accord with phase chemistry as water evaporates and temperatures change thereby creating a second pond liquor with increased sodium carbonate concentration. Alternatively transferring at least a portion of the second pond liquor back to the first pond or into an optional third pond.

A multi-pond system and method is disclosed for separating sodium carbonate from sodium chloride in process purge streams from soda ash production or similar facilities. The system comprises a first pond, exposed to atmospheric environment, for receiving the process purge stream and allowing deposition of sodium carbonate in accord with phase chemistry as water is evaporated and temperatures change thereby creating a liquor with increased sodium chloride concentration. A second pond for receiving the first pond liquor, exposed to the atmospheric environment, and allowing deposition of sodium chloride in accord with phase chemistry as water evaporates and temperatures change thereby creating a second pond liquor with increased sodium carbonate concentration. Alternatively transferring at least a portion of the second pond liquor back to the first pond or into an optional third pond.