A recycling treatment system for tannery wastewater is fixed between a sequencing batch reactor (SBR) and filter press equipment, and the recycling treatment system contains: a first ultrafiltration unit, a second ultrafiltration unit, a cation exchange unit, an osmosis processing unit, a recycling tank, a RO concentration tank, and an evaporation unit. The first ultrafiltration unit includes a filtering tank, a plurality of ultrafiltration sets with plural first ultrafiltration bags and a fluid tube. The second ultrafiltration unit includes a concentration tank, at least one rotary ultrafiltration assembly, a backwash pipe, and a discharge pipe. The cation exchange unit includes a reaction sink and cationic resin. The osmosis processing unit includes plural first reverse osmosis sets and plural second reverse osmosis sets. The RO concentration tank is mounted beside the osmosis processing unit, and the evaporation unit is configured between the RO concentration tank and the recycling tank.

There is provided a process and system for treating produced water. The process combines a vacuum tank process, an adsorption-desorption process, a heat-exchanger process, a membrane distillation-crystallization process. Also, the process may involve membrane separation and column distillation processes. The process allows for some level of efficiency with regard to energy consumption and operational and maintenance costs.

A hybrid electro-pressure driven method for the recovery, purification, and concentration of lithium salts is described. A fractionating electrodialysis stack equipped with selective ion exchange membranes is used to separate a lithium containing brine into a monovalent enriched fraction and a divalent enriched fraction. The monovalent enriched fraction is further processed to remove remaining impurities by use of pressure driven nanofiltration. An optional concentrating electrodialysis device may further concentrate the monovalent enriched fraction in lithium content. The method may be combined with a subsequent solvent extraction and electrolysis step to produce lithium hydroxide, a Li+ selective sorbent step for producing purified lithium chloride, or a Li+ selective sorbent and precipitative step to produce lithium carbonate.

A method is disclosed for concentrating and purifying an eluate brine and producing a purified lithium compound. An extraction eluate, rich in lithium, is directed to a nanofiltration unit or a softening process that removes sulfate and/or calcium and magnesium. Permeate from the nanofiltration unit or the effluent from the softening process is directed through an electrodialysis unit. As the lithium-rich solution moves through the electrodialysis unit, lithium, sodium and chloride ions pass from the solution through a cation-transfer membrane and an anion-transfer membrane to concentrate compartments. A dilute stream is directed through the concentrate compartments and collects the lithium, sodium and chloride ions. The electrodialysis unit also produces a product stream which contains non-ionized impurities, such as silica and/or boron. Concentrate from the electrodialysis unit is subject to a precipitation process that produces a lithium compound that is subsequently subjected to a purification process.

A method 30 and an apparatus 31 for mineral extraction. The method 30 comprising providing a solution comprising 40 a plurality of solutes and selectively extracting a mineral from the solution 60 by adsorption to provide a mineral-rich solution. The method further comprises distilling the mineral-rich solution by membrane distillation 80 to increase the concentration of the mineral in the mineral-rich solution and subsequently removing the mineral from the mineral-rich solution 90.

The present invention relates to an integrated electrochemical lithium extraction process to directly produce lithium hydroxide from geothermal brine. The process integrates electrochemical silica removal, selective uptake and release of lithium using an intercalation material, and electro-driven generation of hydroxy (OH.sup.) ions.

The Thermodesalination Device has the capability of employing reverse osmosis via a specialized desalination system. This specialized desalination system is integrated into the upper portion of a steam turbine generator that separates seawater into fresh water and concentrated brine, for preferred allocation. The disclosed desalination device includes a reverse osmosis (RO) membrane comprising a solute side and a solvent side and vanes configured to strengthen a sheer of the RO membrane. The disclosure also includes a steam turbine configured to superheat a saltwater input and create a pressurized and superheated saltwater output on the solute side of the RO membrane. The disclosure yet includes a freezer configured to freeze a brine output from the solute side of the RO membrane into the shape of salt crystals.

There are provided processes for preparing a metal hydroxide comprising (i) at least one metal chosen from nickel and cobalt and optionally (ii) at least one metal chosen from manganese, lithium, copper, magnesium and aluminum, the process comprising:

reacting a metal sulfate comprising (i) at least one metal chosen from nickel and cobalt and optionally (ii) at least one metal chosen from manganese, lithium, copper, magnesium and aluminum with lithium hydroxide, sodium hydroxide and/or potassium hydroxide and optionally a chelating agent in order to obtain a solid comprising the metal hydroxide and a liquid comprising lithium sulfate, sodium sulfate and/or potassium sulfate;

separating the liquid and the solid from one another to obtain the metal hydroxide;

submitting the liquid comprising lithium sulfate, sodium sulfate and/or potassium sulfate to an electromembrane process for converting the lithium sulfate, sodium sulfate and/or potassium sulfate into lithium hydroxide, sodium hydroxide and/or potassium hydroxide respectively;

reusing the sodium hydroxide obtained by the electromembrane process for reacting with the metal sulfate; and

reusing the lithium hydroxide obtained by the electromembrane process for reacting with the metal sulfate and/or with the metal hydroxide.

The presently disclosed technology is directed to systems and methods of separating a solvent in a solution from a solute in the solution by introducing the solution to a separation vessel including an adhesion-resistant membrane adapted to selectively allow the solvent to permeate through the adhesion-resistant membrane without the solute, moving the solvent of the solution from a first side of the adhesion-resistant membrane to a second side of the adhesion-resistant membrane, wherein fluid communication between the first side and the second side is through the adhesion-resistant membrane, saturating the solute on the first side to form a supersaturated solution, and maintaining the supersaturated solution in the vessel for a predetermined time to nucleate crystals of the solute to satisfy a crystallization condition.

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.