Abstract: A process for removing a solvent from a source solution, said process comprising a) contacting the source solution with one side of a selectively permeable membrane, b) contacting a draw solution having a higher osmotic pressure (higher solute concentration) than the source solution with the opposite side of the membrane, such that solvent from the source solution passes across the membrane to dilute the draw solution by direct osmosis, c) removing solvent from the diluted draw solution to regenerate the draw solution, and d) recycling the regenerated draw solution to step a), characterized in that a portion of the draw solution is discarded or treated before and/or after the draw solution is regenerated in step c) so as to reduce the concentration of any solute species present in the draw solution from the source solution.

Abstract: The present invention relates to a antisolvent solidification process wherein a liquid medium comprising at least one organic or inorganic compound which is to be solidified is forced through a membrane into one or more antisolvents, or wherein one or more antisolvents are forced through a membrane into a liquid medium comprising at least one organic or inorganic compound which is to be solidified, yielding a composition comprising solid particles comprising said organic and/or inorganic compound(s).

Abstract: A process for formulating high purity potassium chloride from a carnallite source. The process takes advantage of solubility differences and saturation levels in a multiple salt system generated upon dissolution of carnallite. In the system, the sodium chloride is kept in solution and the magnesium chloride present in the system is controlled to be in a concentration range of between 12% and 25% by weight. This avoids co-precipitation of sodium chloride with the potassium chloride during crystallization and therefore prevents the sodium chloride from contaminating the potassium chloride. The result is high grade potassium chloride.

Abstract: The present invention relates to process to prepare a chlorine-containing compound using an aqueous salt solution containing at least 100 g/l of sodium chloride and a contaminating amount of polyvalent cations comprising the steps of (i) preparing an aqueous salt solution containing at least 100 g/l of sodium chloride and at least 0.01 ppm of polyvalent cations by dissolving a sodium chloride source in water, (ii) adding an effective amount of at least one positive retention enhancing component to the aqueous solution, (iii) subsequently subjecting the solution to a nanofiltration step, thereby separating the solution into a retentate which is enriched for polyvalent cations and a permeate which is the purified aqueous salt solution, (iv) reacting the chloride anions in the permeate to a chlorine-containing compound by an electrolysis step, and (v) recycling at least part of the retentate to dissolution step (i).

Abstract: The present invention relates to a process to prepare salt comprising the following steps: (i) preparing an aqueous salt solution containing at least 100 g/l of sodium chloride and at least 0.01 ppm of polyvalent cations by dissolving a sodium chloride source in industrial water, (ii) adding an effective amount of at least one positive retention enhancing component to the aqueous salt solution, (iii) subsequently subjecting the solution to a nanofiltration step, thereby separating the solution into a retentate which is enriched for the polyvalent cations and a permeate which is the purified aqueous salt solution, and (iv) concentrating the permeate to produce salt.

Abstract: The present invention pertains to a process for producing sodium chloride comprising the steps of (i) preparing a brine comprising at least 150 g/l of sodium chloride by dissolving a sodium chloride source in water, (ii) subjecting the resulting brine to a eutectic freeze crystallization step by indirect cooling of said brine, resulting in the formation of ice, sodium chloride dihydrate, and a mother liquor, (iii) separating the sodium chloride dihydrate formed in step (ii) from the ice and optionally mother liquor at the eutectic temperature, such that a sodium chloride dihydrate-rich stream is formed, and (iv) feeding said sodium chloride dihydrate-rich stream to a recrystallizer to form sodium chloride and a mother liquor.

Abstract: The present invention relates to a method for making pure salt comprises recapturing post-drilling flowback water from hydro-fracturing; removing oil from the flowback water; filtering the flowback water using an ultra filter with a pore size of about 0.1 microns or less to remove solid particulates and large organic molecules, such as benzene, ethylbenzene, toluene, and xylene, from the water; concentrating the flowback water to produce a brine that contains from about 15 wt % to about 40 wt % of salt relative to the total weight of the flowback brine; performing one or more chemical precipitation process using an effective amount of reagents to precipitate out the desired high quality commercial products, such as, barium sulfate, strontium carbonate, calcium carbonate; and crystallizing the chemically treated and concentrated flowback brine to produce greater than 99.5% pure salt products, such as sodium and calcium chloride.

Abstract: The invention pertains to removing soluble alkali metal or ammonium salt of a divalent anion from brine comprising following steps: obtaining brine with NaCl-concentration between 150g/L and saturation in the presence or absense of a cyrstal growth inhibitor for NaCl(GCI-NaCl),or with NaCl concentration above saturation in the presence of a CGI-NaCl, said brine optionally comprising a crystal growth inhibitor for the alkali metal or ammonium salt of the divalent anion(CGI-DA); if necessary, acidify the solution to pH<11.5; if the concentration of CGI-DA is less than 20 mg/L, adding CGI-DA to obtain at least 20 mg CGI-DA/L; subjecting the solution to a membrane filtration; if the concentration of CGI-DA in the concentration from the separation is less than 20 mg/L, adding CGI-DA to obtain at least 20 mg CGI-DA/L; crystalling the concentration; removing the crystallized alkali metal or ammonium salt of the divalent anion.

Abstract: A process comprising receiving production saltwater comprising water, salt, and hydrocarbons, separating substantially all of the hydrocarbons from the production saltwater, evaporating at least some of the water in the production saltwater to obtain the salt, and collecting the salt. Also disclosed is a facility comprising a settling pit, an evaporator in fluid communication with the settling pit and comprising a nozzle configured to emit a stream along a path, and a collection pit positioned under the path.

Abstract: To provide a method for producing polycrystalline silicon at relatively low cost, wherein the amount of waste generated is reduced by decreasing the amount of waste generated in producing polycrystalline silicon from silicon chloride by a method of reduction and increasing the amount of reused auxiliary raw materials. In the production of polycrystalline silicon using a gas phase reaction of a silicon chloride gas and a reducing agent gas, a chlorine gas is blown into an exhaust gas discharged from a reaction device to initiate a reaction, an unreacted reducing agent and silicon particles contained in the exhaust gas are chlorinated, and then a reducing agent chloride contained in the exhaust gas is separated from the other impurities and recovered.

Abstract: The process of the invention is an improvement over the existing process of producing salt of high purity from alum-treated brine disclosed recently in the prior art. More particularly, the invention rectifies the ratio of Ca2+ to Mg2+ from a value <1 to a value in the range of 2-3 desired by chlor-alkali and soda ash industries. The improved process involves the adjustment of pH of clarified brine with aqueous HCl so as to carry out salt crystallization at a pH of 6.5 instead of at the natural pH of 7. The pH adjustment reduces the Mg2+ impurity in salt while slightly raising the Ca2+ impurity in the salt and thereby achieving the desired ratio.

Abstract: The invention relates to a process to produce brine of improved purity wherein a salt source, contaminated with sulphate ions and alkaline (earth) metal ions, is dissolved in water in the presence of an effective amount of a retarding agent comprising at least one low and at least one high molecular weight retarding agent. Said retarding agent effectively reduces the level of the alkaline (earth) metal sulphate dissolved in the brine, particularly the amount of calcium and sulphate. Preferably, the combination of the low and high molecular weight retarding agents is synergetic in the reduction of dissolved alkaline-earth metal sulphate.

Abstract: This invention relates to methods and installations for producing ultra pure sodium chloride salt crystals primarily for use in saturating depleted brine resulting from the electrolytic decomposition of saturated brine in chlor alkali membrane cells for the production of chlorine, caustic soda and hydrogen. More particularly, this invention relates to the production of ultra pure sodium chloride salt crystals by processing primary treated brine by first acidifying the primary treated brine, then stripping the carbonic acid produced by acidification as carbon dioxide, and then returning the brine to a pH of about 6 or higher which is sufficient for processing it in evaporation equipment where the ultra pure salt crystals are produced.

Abstract: Silazanes and/or polysilazanes are prepared by ammonolysis reaction in liquid anhydrous ammonia by introducing at least one halosilane into the ammonia. In addition to the silazane and/or polysilazane, an ammonolysis by-product also results. A substantially more efficient process is disclosed for treating the by-product through the addition of a liquid, namely water, or a solution comprising a strong base, or an aqueous acid solution. The process may be employed for more efficient, economical recovery of ammonia from such waste stream solutions of ammonia halide, or acids thereof for use as recycle in the further production of silazanes and polysilazanes, and/or for producing a less hazardous, more readily disposable salt residue thereof.

Abstract: A sodium-based dechlorinating agent is added to a flue gas; hydrogen chloride contained in this flue gas is removed as residue of dechlorination; the thus removed residue of dechlorination is dissolved by adding water; water-insoluble constituents are separated from the resulting aqueous solution; and after adjusting pH of the aqueous solution remaining after separation of the water-insoluble constituents, mercury, dioxin, and the like are removed and discharged. The sodium-based dechlorinating agent is mixed with a hydrophilic anti-caking agent, with an angle of repose of 40° or more, a dispersibility of less than 50, and a floodability index value of less than 90. This permits inhibition of occurrence of a pressure drop and leakage in the filter cloth of the dust collector.

Abstract: An object of the present invention is to provide an effective and efficient process for the treatment of an inorganic salt containing an organic material which can solve various problems with the prior art, i.e., process for purifying an inorganic salt containing an organic material to an extent such that it can be recovered and re-used from the standpoint of environmental protection and utilization of resources. An inorganic salt containing an organic material is granulated or subjected to chemical treatment (mixed with an alkali and/or oxidizing agent), and then subjected to heat treatment so that it is purified.

Abstract: A new process for recovery of Low Sodium Salt from bittern has been described in the present invention, the said process comprising desulphatation of bittern (by-product of salt industry), evaporation of bittern in solar pans and processing of solid mixture with water to produce a mixture of sodium and potassium chlorides and optionally preparing “free flowing” and iodized, by known techniques.

Abstract: The invention relates to a process to produce brine of improved purity by dissolving salt that contains a calcium sulfate source in water, in the presence of a retarding agent, while using one or more co-retardants to bind contaminants that could interfere with the retarding agents.

Abstract: A method and apparatus for removing BHP contaminants (alkali hydroxide and H2O2) from a recycled aqueous alkali chloride solution stream before the stream is fed to a chloralkali cell so that the contaminants do not impair the operation of a chloralkali cell. Unwanted alkali hydroxide within the recycled alkali chloride brine solution is reacted with chlorine gas and converted into an alkali chloride, which is useful in the operation of the chloralkali cell, and oxygen gas, which is outgassed from the system. Any H2O2 remaining in the recycled stream after elimination of the alkali hydroxide is reacted with chlorine to form HCl and oxygen gas. The HCl raises the pH of the brine solution, after which the pH may be adjusted by the addition of supplemental alkali hydroxide.

Abstract: Process for the production of sodium chloride crystals from a sodium chloride brine contaminated by potassium chloride and sulphate ions, according to which a calcium compound (32) is added to the brine (48) to crystallize glauberite (35), which is isolated, the resulting aqueous solution (36) is subjected to evaporation to crystallize sodium chloride (40), which is collected, and the aqueous mother liquor (41) from the crystallization of the sodium chloride is subjected to cooling (42) to crystallize glaserite (45).

Abstract: A method and apparatus for removing BHP contaminants (alkali hydroxide and H2O2) from a recycled aqueous alkali chloride solution stream before the stream is fed to a chloralkali cell so that the contaminants do not impair the operation of a chloralkali cell. Unwanted alkali hydroxide within the recycled alkali chloride brine solution is reacted with chlorine gas and converted into an alkali chloride, which is useful in the operation of the chloralkali cell, and oxygen gas, which is outgassed from the system. Any H2O2 remaining in the recycled stream after elimination of the alkali hydroxide is reacted with chlorine to form HCl and oxygen gas. The HCl raises the pH of the brine solution, after which the pH may be adjusted by the addition of supplemental alkali hydroxide.

Abstract: Process for the manufacture of an aqueous sodium chloride solution, according to which a solid material comprising sodium chloride and heavy metals is dispersed in water, the aqueous medium thus obtained is alkalinized so as to precipitate the heavy metals in the form of metal hydroxides, calcium carbonate is coprecipitated with the metal hydroxides in the aqueous medium and the aqueous medium is then subjected to mechanical clarification.

Abstract: Chloride is selectively isolated as NaCl from N-phosphonomethyliminodiacetic acid process wastes by evaporative crystallization of the caustic neutralized brine.

Abstract: A process for separating a solid compound other than lithium hydroxide, such as sodium chloride, in which lithium hydroxide is hydrosulfurized by bubbling gaseous hydrogen sulfide through an aprotic solvent, such as a polar organic compound, containing lithium hydroxide and the solid compound other than lithium hydroxide, solid-liquid separation is conducted under a condition in which the reaction of lithium hydrosulfide to lithium sulfide and hydrogen sulfide is suppressed and at a temperature of the liquid for separation at 50 to 150° C., and the separated crystal cake is further washed with the aprotic solvent to highly recover lithium hydrosulfide.

Abstract: A method of removing from a metal salt ionic species contained therein involves contacting the metal salt with an ionic liquid to dissolve the metal salt, the ionic species or both. At least in the case where both the metal salt and the ionic species are dissolved, the resultant ionic liquid composition is treated to separate the ionic species therefrom and subsequently processed to recover the metal salt.

Abstract: Aqueous alkali metal chloride solutions, typically destined for electrolysis for the production of chlorine and containing a contaminating amount of iodine values in other than the periodate state, are purified by oxidizing the iodine values therein to the periodate oxidation state of +7 and then separating such periodate values therefrom. The starting alkali metal chloride solutions may also contain contaminating amounts of ammonium values, which in turn are oxidized, preferably simultaneously, to molecular nitrogen and degassed therefrom.

Abstract: An object of the present invention is to provide an effective and efficient process for the treatment of an inorganic salt containing an organic material which can solve various problems with the prior art, i.e., process for purifying an inorganic salt containing an organic material to an extent such that it can be recovered and re-used from the standpoint of environmental protection and utilization of resources. An inorganic salt containing an organic material is granulated or subjected to chemical treatment (mixed with an alkali and/or oxidizing agent), and then subjected to heat treatment so that it is purified.