A method for recovering sodium from a sodium-sulfur battery of the present invention includes a reaction step of injecting a treatment liquid toward the sodium housed in a sodium-housing component in the battery container and causing the sodium to react with the treatment liquid so as to generate a reaction liquid; and a circulation step of generating the treatment liquid by adjusting the concentration and liquid temperature of the reaction liquid, and, in the reaction step, while the entire amount of the sodium is reacted with the treatment liquid, the treatment liquid is continuously injected toward the sodium.

This invention relates to treated geothermal brine compositions containing reduced concentrations of silica, iron, and potassium compared to the untreated brines. Exemplary compositions of the treated brine contain a concentration of silica ranging from about 0 mg/kg to about 15 mg/kg, a concentration of iron ranging from about 0 mg/kg to about 10 mg/kg, and a concentration of potassium ranging from about 300 mg/kg to about 8500 mg/kg. Other exemplary compositions of the treated brines also contain reduced concentrations of elements like rubidium, cesium, and lithium.

This invention relates to treated geothermal brine compositions containing reduced concentrations of silica, iron, and potassium compared to the untreated brines. Exemplary compositions of the treated brine contain a concentration of silica ranging from about 0 mg/kg to about 15 mg/kg, a concentration of iron ranging from about 0 mg/kg to about 10 mg/kg, and a concentration of potassium ranging from about 300 mg/kg to about 8500 mg/kg. Other exemplary compositions of the treated brines also contain reduced concentrations of elements like rubidium, cesium, and lithium.

A method for treating a purge stream derived from a sodium carbonate, sesquicarbonate, wegsheiderite, or bicarbonate crystallizer, said purge stream comprising sodium carbonate and/or sodium bicarbonate and at least 1% by weight of sodium chloride and/or sodium sulfate, the method comprising: causticizing at least 50 mol. % of the sodium from sodium carbonate and/or sodium bicarbonate into a caustic solution and into a calcium carbonate mud with lime and water, separating the calcium carbonate 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, separating the crystallized solid from the concentrated caustic solution, said crystallized solid to be disposed of or to be further valorized, recycling part of the concentrated caustic solution to the sodium carbonate, sesquicarbonate, wegsheiderite, or bicarbonate crystallizer.

A method for treating a purge stream derived from a sodium carbonate, sesquicarbonate, wegsheiderite, or bicarbonate crystallizer, said purge stream comprising sodium carbonate and/or sodium bicarbonate and at least 1% by weight of sodium chloride and/or sodium sulfate, the method comprising: causticizing at least 50 mol. % of the sodium from sodium carbonate and/or sodium bicarbonate into a caustic solution and into a calcium carbonate mud with lime and water, separating the calcium carbonate 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, separating the crystallized solid from the concentrated caustic solution, said crystallized solid to be disposed of or to be further valorized, recycling part of the concentrated caustic solution to the sodium carbonate, sesquicarbonate, wegsheiderite, or bicarbonate crystallizer.

Methods to recover or separate cesium formate or rubidium formate or both from a mixed alkali metal formate blend are described. One method involves adding cesium sulfate or rubidium sulfate to the mixed alkali metal formate blend in order to preferentially precipitate potassium sulfate from the mixed alkali metal formate blend. Another method involves adding cesium carbonate or cesium bicarbonate or both to preferentially precipitate potassium carbonate/bicarbonate and/or other non-cesium or non-rubidium metals from the mixed alkali metal blend. Further optional steps are also described. Still one other method involves converting cesium sulfate to cesium hydroxide.

Methods to recover or separate cesium formate or rubidium formate or both from a mixed alkali metal formate blend are described. One method involves adding cesium sulfate or rubidium sulfate to the mixed alkali metal formate blend in order to preferentially precipitate potassium sulfate from the mixed alkali metal formate blend. Another method involves adding cesium carbonate or cesium bicarbonate or both to preferentially precipitate potassium carbonate/bicarbonate and/or other non-cesium or non-rubidium metals from the mixed alkali metal blend. Further optional steps are also described. Still one other method involves converting cesium sulfate to cesium hydroxide.

A process of recovering solid potassium/ammonia salts includes: introducing an aqueous stream containing at least one of ammonium cations or potassium cations, and at least one of carbonate anions or bicarbonate anions into a treatment unit; introducing a carbon dioxide stream containing CO.sub.2 into the treatment unit; contacting the aqueous stream with the carbon dioxide stream to form a mixture; removing heat from the treatment unit to control a temperature of the mixture; forming a slurry from the mixture, the slurry including water and at least one of a solid potassium salt, or a solid ammonium salt; withdrawing the slurry from the treatment unit as a treated aqueous stream; and introducing the treated aqueous stream into a separator to generate a brine stream, and a recovered potassium and/or ammonia salt stream containing at least one of the solid potassium salt or the solid ammonium salt.

A process of recovering solid potassium/ammonia salts includes: introducing an aqueous stream containing at least one of ammonium cations or potassium cations, and at least one of carbonate anions or bicarbonate anions into a treatment unit; introducing a carbon dioxide stream containing CO.sub.2 into the treatment unit; contacting the aqueous stream with the carbon dioxide stream to form a mixture; removing heat from the treatment unit to control a temperature of the mixture; forming a slurry from the mixture, the slurry including water and at least one of a solid potassium salt, or a solid ammonium salt; withdrawing the slurry from the treatment unit as a treated aqueous stream; and introducing the treated aqueous stream into a separator to generate a brine stream, and a recovered potassium and/or ammonia salt stream containing at least one of the solid potassium salt or the solid ammonium salt.

Provided is a water-insoluble crosslinked structure with an excellent metal-adsorbing effect. The crosslinked structure is formed by crosslinking a first linear polymer and a second linear polymer. The first linear polymer has a plurality of pendant groups represented by Formula (a). The second linear polymer has a plurality of pendant groups represented by Formula (a). Some of the plurality of pendant groups in the first linear polymer and some of the plurality of pendant groups in the second linear polymer are bonded to each other via a crosslinker. In the formula, ring Z represents a heterocycle containing a nitrogen atom as a heteroatom, R.sup.1 represents a single bond or an alkylene group having from 1 to 10 carbons, and Q.sup.+ represents a counter cation.

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