Provided are: an economically superior protein crystallization method capable of efficiently finding conditions for crystallization by using a small amount of protein; and a crystallization device used for the method. According to the present invention, a transparent sealed container 1 is filled with a solution of protein, a part of the transparent sealed container 1 being formed of a semipermeable membrane 2 with a molecular weight cut-off that inhibits passage of the protein while allowing passage of a precipitant, and then, a precipitant solution with changed concentration and/or pH of the precipitant is continuously supplied to the semipermeable membrane 2, to crystallize the protein with the precipitant that infiltrates from the semipermeable membrane 2 into the sealed container 1.

A method for highly concentrating aqueous solutions containing thermally sensitive organic constituents and with or without mineral constituents, wherein firstly, a major portion of the water is extracted by membrane filtration from the solution for pre-concentration and is discharged from the process and the solution which is pre-concentrated is then subjected to a freeze concentration procedure, in which, in the form of separated ice crystallisate, further water is extracted from the solution. To promote results, that concentration may be effected in the freeze concentration procedure until a viscosity of the mother solution of at least 0.0002 m.sup.2/s is achieved, and in that the separated ice crystallisate from the freeze concentration with the mother solution adhering thereto as a suspension is returned to the membrane filtration upstream of the membrane filtration or after melting of the ice crystallisate.

The present disclosure provides methods of controlling the size of cellulose crystals by mixing a first composition comprising cellulose and coagulating this mixture with varying concentrations of hydrogen peroxide.

The present disclosure provides a method and a system for extracting long chain dicarboxylic acid, the method comprising: (1) subjecting a long chain dicarboxylic acid fermentation broth to a primary membrane filtration treatment to give a first filtrate; subjecting the first filtrate to decolorization, acidification/crystallization, and solid-liquid separation treatments to give a first solid; (2) mixing the first solid, a base and water to form a solution; subjecting the solution to a secondary membrane filtration treatment to give a second filtrate; subjecting the second filtrate to decolorization, acidification/crystallization, and solid-liquid separation treatments to give a second solid; and (3) mixing the second solid and water to form a mixture; subjecting the mixture to a thermostatic treatment at 105-150° C., followed by cooling for crystallization and solid-liquid separation treatment. By the method, the resulted long chain dicarboxylic acid product has a high purity and no residual organic solvent.

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.

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 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 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.

A resource recovery method includes: feeding raw water to a first-stage raw water tank; supplying high-temperature vapor to a first-stage heat exchanger; performing heat exchange between the supplied high-temperature vapor and the raw water in the first-stage raw water tank, changing a portion of the water into vapor and supplying the changed vapor to a subsequent-stage heat exchanger; repeatedly performing the performing step for each of the raw water tanks sequentially in the order from a second state to a n-th stage; being feed to a crystallizer from the n-th stage raw water tank; detecting a turbidity of the raw water fed to the crystallizer from the n-th-stage raw water tank; and extracting crystals of valuable resources contained in the raw water fed to the crystallizer from the n-th-stage raw water tank when the turbidity of the raw water becomes a predetermined value.

A method for treating waste water containing ammonia comprising the steps of: i) passing the waste water as a feed solution through a first RO membrane (24) to produce a first permeate stream (30) and a first reject stream (32), ii) adjusting the pH of the first reject stream (32) to >9, iii) passing the first reject stream (32) through a second RO membrane (26) to produce a second permeate stream (36) containing ammonia and a second reject stream (38), and iv) passing at least a portion of the second permeate stream (36) to a cooling tower (12) to evaporate at least a portion of the ammonia.

A process for the removal of divalent cations, such as calcium and magnesium, from a saline aqueous solution such as a natural brine comprising lithium, using an electrolytic cell comprising at least one anion exchange membrane. The process allows removal of undesired components before lithium recovery, by reducing their concentrations to less than 0.1% of their original concentration in the brine while the lithium concentration remains unchanged.

A method of producing lactic acid includes filtering a lactic acid-containing aqueous solution through a nanofiltration membrane to recover an aqueous lactic acid solution from the permeate side (Step A); distilling the aqueous lactic acid solution to recover lactic acid from the vapor side (Step B); and crystallizing the lactic acid obtain in Step B, and performing solid-liquid separation to recover a lactic acid crystal(s) (Step C).