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.

An evaporation still for producing sea salt having a chamber that contains a bottom, a plurality of sides including a front side, a back side, a first side, and a second side, the front side and the back side being substantially parallel, and the first side and the second size being substantially parallel, and a top. The top contains a centered portion extending from the first side to the second side, the centered portion being substantially parallel to the front side and the back side, a first window extending in a downward slope from the centered portion towards the front side, and a second window extending in a downward slope from the centered portion towards the back side. The evaporation still also contains a plurality of legs. The first window extends from the centered portion beyond the front side such that condensation formed inside of the chamber drains outside of the chamber, and the second window extends from the centered portion beyond the back side such that condensation formed inside of the chamber drains outside of the chamber.

An evaporation still for producing sea salt having a chamber that contains a bottom, a plurality of sides including a front side, a back side, a first side, and a second side, the front side and the back side being substantially parallel, and the first side and the second size being substantially parallel, and a top. The top contains a centered portion extending from the first side to the second side, the centered portion being substantially parallel to the front side and the back side, a first window extending in a downward slope from the centered portion towards the front side, and a second window extending in a downward slope from the centered portion towards the back side. The evaporation still also contains a plurality of legs. The first window extends from the centered portion beyond the front side such that condensation formed inside of the chamber drains outside of the chamber, and the second window extends from the centered portion beyond the back side such that condensation formed inside of the chamber drains outside of the chamber.

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.

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 process for treating wastewater or waste brines that include sodium and chloride ions. The waste brine is concentrated and thereafter directed to a Mirabilite crystallizer that produces hydrated sulfate salt crystals and a first solution. The hydrated crystals are melted to form an aqueous sulfate solution that is directed to a sodium sulfate crystallizer which produces sodium sulfate salt crystals. The first solution produced by the Mirabilite crystallizer is directed to a nanofiltration device which produces a permeate stream and a reject stream containing sulfate removed by the nanofiltration device. The permeate stream is directed to a sodium chloride crystallizer that produces sodium chloride salt crystals. The reject stream is recycled to the Mirabilite crystallizer.

A process for treating wastewater or waste brines that include sodium and chloride ions. The waste brine is concentrated and thereafter directed to a Mirabilite crystallizer that produces hydrated sulfate salt crystals and a first solution. The hydrated crystals are melted to form an aqueous sulfate solution that is directed to a sodium sulfate crystallizer which produces sodium sulfate salt crystals. The first solution produced by the Mirabilite crystallizer is directed to a nanofiltration device which produces a permeate stream and a reject stream containing sulfate removed by the nanofiltration device. The permeate stream is directed to a sodium chloride crystallizer that produces sodium chloride salt crystals. The reject stream is recycled to the Mirabilite crystallizer.

A process for the work-up of salt-containing process water which contains an alkali metal chloride as salt in a concentration of at least 4% by weight and organic or inorganic and organic impurities from chemical production processes and reuse of the salt by a combination of prepurification and concentration, crystallization and purification of the salt and optionally subsequently use of the salt in an electrolysis for producing basic chemicals are described.