A renewable magnesium removing agent and its use in a preparation of a low-magnesium lithium-rich brine are provided. The magnesium removing agent includes a magnesium phosphate double salt of an alkali metal or ammonium. A regeneration of the magnesium removing agent is realized by adding the magnesium removing agent into Mg.sup.2+-containing chloride salt solution, wherein Mg.sup.2+ in the chloride salt solution and the magnesium removing agent are subjected to a magnesium removing reaction to form a solid-phase reaction product and carrying out a solid-liquid separation on an obtained mixed reaction product after the magnesium removing reaction is ended to separate the solid-phase material comprising a magnesium phosphate hydrate and then separating out a chlorine salt of the alkali metal or the ammonium from a remaining liquid-phase material, and finally carrying out a regeneration reaction on the magnesium phosphate hydrate and the chlorine salt of the alkali metal or the ammonium.

A renewable magnesium removing agent and its use in a preparation of a low-magnesium lithium-rich brine are provided. The magnesium removing agent includes a magnesium phosphate double salt of an alkali metal or ammonium. A regeneration of the magnesium removing agent is realized by adding the magnesium removing agent into Mg.sup.2+-containing chloride salt solution, wherein Mg.sup.2+ in the chloride salt solution and the magnesium removing agent are subjected to a magnesium removing reaction to form a solid-phase reaction product and carrying out a solid-liquid separation on an obtained mixed reaction product after the magnesium removing reaction is ended to separate the solid-phase material comprising a magnesium phosphate hydrate and then separating out a chlorine salt of the alkali metal or the ammonium from a remaining liquid-phase material, and finally carrying out a regeneration reaction on the magnesium phosphate hydrate and the chlorine salt of the alkali metal or the ammonium.

A procedure of minimum environmental impact and maximum lithium recovery for obtaining concentrated brines with minimal impurity content from brines that embed natural salt flats and salt marshes. The procedure may include: building fractional crystallization ponds by solar evaporation; filling the ponds with natural brine; pre-concentrating natural brine to the maximum possible lithium concentration in the liquid phase without precipitating lithium-containing salts; cooling the pre-concentrated brine obtained in ensuring maximum precipitation of salts containing sulfate anion; chemically pre-treating the liquid phase of brine separated from precipitated salts by cooling to minimize sulfate anions in the liquid phase after cooling; pre-concentrating the pre-treated liquid phase to the maximum possible lithium concentration without precipitating lithium-containing salts; chemically treating the liquid phase of brine separated from precipitated salts to minimize the concentration of magnesium, calcium, boron and sulfate in the liquid phase; and concentrating the resulting liquid phase.

The present invention relates to a salt recovery solution and to a process for separating a salt from an aqueous solution. The present disclosure also relates to a salt recovery solution and to its use to concentrate a salt or brine solution by recovering water therefrom. The salt recovery solution comprising at least two or more components independently selected from any combination of integers a), b), c) and d): where a) is a straight, branched or optionally substituted cyclic C.sub.4-C.sub.9 ether containing compound; b) is a straight chain or branched C.sub.3-C.sub.9 alkyl substituted by —OH; c) is a straight chain, branched or cyclic C.sub.4-C.sub.9 ketone or C.sub.4-C.sub.9 diketone; and d) is a straight chain or branched C.sub.3-C.sub.9 ester containing compound.

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 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 system and method for producing minerals from divalent ion-containing brine stream includes rejecting sulfate from a divalent-ion rich reject stream in a first nanofiltration seawater reverse osmosis (NF-SWRO) unit, producing solid calcium sulfate dihydrate and a magnesium-rich brine stream in a first concentration unit, concentrating the magnesium-rich brine stream to a saturation point of sodium chloride in a second concentration unit, producing solid sodium chloride and a supernatant product stream in a first crystallizing unit, produce a concentrated magnesium-rich bittern stream from the supernatant product stream in a third concentration unit, and at least one of producing hydrated magnesium chloride from the concentrated magnesium-rich bittern stream in a second crystallizing unit and producing anhydrous magnesium chloride by prilling the concentrated magnesium-rich bitterns stream under a hydrogen chloride atmosphere in a dry air process unit.

The present invention provides a method for reducing the concentration of aluminum and nickel cations in a brine comprising aluminum and nickel cations. The treated brine can be used as a feedstock to membrane cell chlor-alkali process.

The present invention provides a method for reducing the concentration of aluminum and nickel cations in a brine comprising aluminum and nickel cations. The treated brine can be used as a feedstock to membrane cell chlor-alkali process.

A method including capturing carbon dioxide (CO.sub.2) from air (e.g., atmosphere) in an absorber in which the air contacts a base (e.g., a hydroxide, such as potassium hydroxide KOH and/or sodium hydroxide (NaOH)) to produce a carbonate (e.g., potassium carbonate (K.sub.2CO.sub.3) and/or sodium carbonate (Na.sub.2CO.sub.3)); precipitating one or more (e.g., carbonate) salt from an aqueous solution comprising salt (a brine) to provide an aqueous solution comprising a chloride (e.g., potassium chloride (KCl) and/or sodium chloride (NaCl)); using electrochemical regeneration to convert the chloride to electrochemically regenerated product comprising the base (e.g., KOH and/or NaOH); and recycling at least a portion of the electrochemically regenerated product comprising the base to the capturing of the CO.sub.2 from the air. A system for carrying out the method is also provided.