Abstract: The present invention relates to a process for producing sodium bicarbonate crystals. Sodium carbonate derived from TRONA ore is mixed with a treated mother liquor produced in a downstream process to form a sodium carbonate solution. The sodium carbonate solution is subjected to a crystallization process that produces sodium bicarbonate crystals. The sodium bicarbonate crystals are separated from the sodium carbonate solution to form a mother liquor that includes silica. To remove the silica in the mother liquor, the mother liquor is directed to a reactor where an aluminum salt is mixed with the mother liquor to precipitate hydrous aluminum oxide which adsorbs silica thereon. The hydrous aluminum oxide with adsorbed silica is removed from the mother liquor. This produces the treated mother liquor that is mixed with the sodium carbonate and which forms the sodium carbonate solutions.

Abstract: The purpose of the present invention is to provide a method for recovering calcium-containing solid components from steelmaking slag, with which it is possible to easily increase the calcium recovery rate. With the method, steelmaking slag is immersed in an aqueous solution containing carbon dioxide, and calcium in the steelmaking slag is made to leach out into the aqueous solution. Next, the immersed steelmaking slag is removed from the aqueous solution, and, subsequently, the pH of the aqueous solution is increased. When solid components precipitated by doing so are recovered, it is possible to recover solid components containing 20% or more by mass in terms of calcium atoms.

Abstract: We have described herein a method and associated apparatus that can halt global warming with significant economic benefits. They include re-scrubbing half the carbon dioxide emitted from calcining baking soda into soda ash to produce twice as much soda ash and twice as much ammonium chloride as compared with the standard Solvay ammonia soda ash process, collecting from calcining exhaust a carbon dioxide and water mixture, transferring the carbon dioxide and water mixture to a hydraulic press for use as a multi component working medium.

Abstract: The present invention relates to a continuous process for the production of a superabsorbent polymer comprising providing an acidic liquid aqueous monomer mixture containing dissolved oxygen; continuously feeding the aqueous monomer mixture to a reactor; introducing a source of carbonate or hydrogen carbonate into the aqueous monomer mixture prior to entry into the reactor thereby forming a gas phase comprising carbon dioxide and at least a part of the dissolved oxygen, the gas phase being dispersed in the liquid phase; subjecting the gas/liquid mixture to at least partial phase separation immediately prior to or after entry into the reactor and at least partially removing the separated gaseous phase; subjecting the liquid phase in the reactor to free-radical polymerization to obtain the superabsorbent polymer, and continuously removing the superabsorbent polymer from the reactor.

Abstract: Process for the joint production of sodium carbonate and sodium bicarbonate crystals, according to which: a solid powder derived from sodium sesquicarbonate, having a mean particle diameter comprised between 0.1 and 10 mm is dissolved in water; the resulting water solution is introduced into a crystallizer, wherein a first water suspension comprising sodium carbonate crystals is produced; the first water suspension is subjected to a separation, in order to produce crystals comprising sodium carbonate on the one hand, which are valorized, and a mother liquor on the other hand; and a part of the mother liquor is taken out of the crystallizer and put into contact in, a gas liquid contactor, with a gas comprising carbon dioxide, in order to produce a second water suspension comprising sodium bicarbonate crystals, which are separated and valorized. A reagent powder comprising sodium bicarbonate crystals made by such process.

Abstract: A process for producing sodium bicarbonate from a sodium carbonate bearing stream (A) comprising sodium carbonate and an alkaline metal salt impurity at a concentration Ci(A), comprising: a) mixing the stream (A) with part of a stream (B), b) bicarbonating the resulting mixed stream with a gas comprising CO2 to produce an aqueous suspension comprising sodium bicarbonate crystals (F), c) separating the sodium bicarbonate crystals (F) from the aqueous liquor (G), d) partly debicarbonating at least part of (G) and removing part of the water of (G) to obtain the stream (B) with the salt impurity at a concentration Cf(B), e) recycling part of the stream (B) to step a) so that the ratio of the concentrations Cf(B)/Ci(A) of the impurity is at least: 1.4, and f) removing the remainder (I) of the stream (B) or the remainder (J) of the liquor (G) to be further processed.

Abstract: A material with cationic exchanger properties is introduced into aqueous media, where the equilibriums of carbon dioxide dissolution take place. A cationic exchanger material x/nM+nEx? is used to capture hydronium cations (H3O+) according to: x/nM+nEx?(s)+xH3O+(aq)=xH3O+Ex?(s)+x/nM+n(aq) where “x” stands for molar amount of the anionic centers of charge of the cationic exchanger material Ex? balanced by x/n molar amount of metal M, “n” stands for the metal valence, and M is selected from the group consisting of 1A and/or 2A of the periodic table of elements. This capture of the hydronium cations, H3O+, shifts certain reaction equilibriums to the right, according to Le Chatelier's principle, producing more bicarbonate, HCO3?, and/or carbonate, CO3=, than would otherwise be obtained.

Abstract: The present invention provides a kiln for the combustion of agricultural waste. The kiln includes a central cylindrical combustion chamber. The central cylindrical combustion chamber includes a system for the control of combustion air to the combustion chamber. The kiln includes a second concentric cylinder surrounding the central cylindrical combustion chamber. The second concentric cylinder includes a system for the flow of cooling water through the first annulus between the central cylindrical combustion chamber and the second concentric cylinder. The kiln includes a system for the feeding of the agricultural waste into the central combustion chamber. The kiln includes a temperature sensing device to measure and display the temperature within the central combustion chamber during the combustion of the agricultural waste. The kiln includes a system for the recovery of ash from the kiln. In operation, the temperature of combustion is controlled to between 550° C. and 650° C.

Abstract: The process described herein demonstrates a more efficient and effective way to remove certain chemicals from industrial waste water. Specifically, the invention set forth demonstrates a method comprised of at least two steps in which up to 96% of potassium can be removed from an aqueous solution comprising potassium hydroxide.

Abstract: A method of extracting an alkali metal and/or an alkaline earth metal from a mineral including an alkali metal and/or an alkaline earth metal, or a rock containing the mineral, the method including contacting the mineral, with an aqueous composition including formic acid, and to their use in carbon sequestration.

Abstract: The process described herein demonstrates a more efficient and effective way to remove certain chemicals from industrial waste water. Specifically, the invention set forth demonstrates a method comprised of at least two steps in which up to 96% of potassium can be removed from an aqueous solution comprising potassium hydroxide.

Abstract: A method including electrolysis processing using sulfate-based electrolytes includes precipitating sodium sulfate decahydrate from a salt solution and then redissolving sodium sulfate decahydrate to prepare feed of electrolyte solution for the electrolysis processing. Front-end processing may be used to treat mixed salt solutions, including brine solutions. Calcium sulfate reagent may provide a sulfate source to regenerate electrolyte solution following carbon capture, and with carbon dioxide being sequestered in the form of calcium carbonate.

Abstract: A process for producing sodium bicarbonate from a sodium carbonate bearing stream (A) comprising sodium carbonate and an alkaline metal salt impurity at a concentration Ci(A), comprising: a) mixing the stream (A) with part of a stream (B), b) bicarbonating the resulting mixed stream with a gas comprising CO2 to produce an aqueous suspension comprising sodium bicarbonate crystals (F), c) separating the sodium bicarbonate crystals (F) from the aqueous liquor (G), d) partly debicarbonating at least part of (G) and removing part of the water of (G) to obtain the stream (B) with the salt impurity at a concentration Cf(B), e) recycling part of the stream (B) to step a) so that the ratio of the concentrations Cf(B)/Ci(A) of the impurity is at least: 1.4, and f) removing the remainder (I) of the stream (B) or the remainder (J) of the liquor (G) to be further processed.

Abstract: A process for producing sodium bicarbonate from a sodium carbonate bearing stream (A) comprising at least 2% sodium chloride and/or sodium sulfate by weight, a part of such stream (A) being generated by a sodium carbonate crystallizer, comprising: a) mixing the stream (A) with part of a stream (B) to produce a stream (C); b) bicarbonating the stream (C) with a gas (D) comprising CO2 to produce an aqueous suspension (E) containing crystals (F) comprising sodium bicarbonate crystals; c) separating the aqueous suspension (E) to obtain crystals (F) comprising sodium bicarbonate crystals and an aqueous mother liquor (G); d) partly debicarbonating such liquor (G) and removing part of the water to obtain the stream (B) and an optional gas (H); e) recycling at least part of the stream (B) to step a); and f) removing the remainder of the stream (B) or part of the aqueous mother liquor (G) to be further processed.

Abstract: Process for the joint production of sodium carbonate and sodium bicarbonate crystals, according to which: a solid powder derived from sodium sesquicarbonate, having a mean particle diameter comprised between 0.1 and 10 mm is dissolved in water; the resulting water solution is introduced into a crystallizer, wherein a first water suspension comprising sodium carbonate crystals is produced; the first water suspension is subjected to a separation, in order to produce crystals comprising sodium carbonate on the one hand, which are valorized, and a mother liquor on the other hand; and a part of the mother liquor is taken out of the crystallizer and put into contact in, a gas liquid contactor, with a gas comprising carbon dioxide, in order to produce a second water suspension comprising sodium bicarbonate crystals, which are separated and valorized. A reagent powder comprising sodium bicarbonate crystals made by such process.

Abstract: A preparation method of lithium carbonate, in recovering valuable resources of a lithium-ion battery, reducing impurities from lithium carbonate, having a pretreatment process, comprising: a first step cleaning an organic phase containing nickel and lithium prepared by a solvent extraction by use of a sulfuric acid solution containing nickel and enriching lithium in the cleaning solution; a second step extracting a residual nickel only by an organic solvent from a post-cleaning solution in which the lithium is enriched; and a third step controlling pH of the post-extraction solution containing the lithium by ammonia water or lithium hydroxide.

Abstract: A method for producing sodium carbonate monohydrate, according to which an aqueous sodium chloride solution (5) is electrolyzed in a membrane-type cell (1) from which an aqueous sodium hydroxide solution (9) is collected, and carbonated by direct contact with carbon dioxide (15) to form a slurry of crystals of a sodium carbonate monohydrate (16), and the slurry or its mother liquor is evaporated (3) to collect sodium carbonate monohydrate (18).

Abstract: Methods and apparatus for the production of low sodium lithium carbonate and lithium chloride from a brine concentrated to about 6.0 wt % lithium are disclosed. Methods and apparatus for direct recovery of technical grade lithium chloride from the concentrated brine are also disclosed.

Abstract: Disclosed is a process for recovery of uranium from a spent nuclear fuel using a carbonate solution, characterized by excellent proliferation resistance of preventing leaching of transuranium element (TRU) nuclides such as Pu, Np, Am, Cm, etc. from the spent nuclear fuel as well as environmental friendliness of minimizing waste generation, wherein a highly alkaline carbonate solution is used to separate uranium alone from the spent nuclear fuel.

Abstract: Method for producing sodium carbonate, according to which an aqueous sodium chloride solution (5) is electrolyzed in a membrane-type cell (1) from which an aqueous sodium hydroxide solution (9) is collected, and carbonated by direct contact with carbon dioxide (15) to form a slurry of crystals of a sodium carbonate (16), and the slurry or its mother liquor is evaporated (3) to collect sodium carbonate (18).

Abstract: In the methods for treatment of caustic effluents described in the specification, a spent caustic refinery effluent is supplied to a submerged combustion gas evaporator in which hot combustion gas containing carbon dioxide is injected into the caustic liquid to concentrate the liquid and convert a hydroxide constituent to a carbonate. Where the caustic effluent is from a petroleum refinery, oil in the waste liquid is separated from the aqueous constituent before, during or after concentration.

Abstract: Metal carbonates that are insoluble in water but that have a corresponding metal biocarbonate salt that is more than 75% by weight soluble in water are purified by preparing an aqueous slurry of the metal carbonate: introducing carbon dioxide gas to form a corresponding metal biocarbonate solution and heating that solution to form a purified metal carbonate and precipitate it.

Abstract: The process for preparing a cesium and rubidium salt-containing solution includes a hydrothermal digestion of an uncalcined pollucite and/or calcined lepidolite particulate having an average particle size up to 0.5 mm with an aqueous solution of Ca(OH).sub.2 in a suspension with a mole ratio of SiO.sub.2 to CaO of from 1:2.5 to 1:1.25 in a rotary tubular autoclave at a digestion temperature of 200 to 280.degree. C., under a pressure of from 15 to 65 bar and at a suspension density between 8 and 18% by weight for from 0.

Abstract: Sodium and borate ions are separated in supercritical water by addition of dissolved CO.sub.2 to cause precipitation of carbonates and the formation of boric acid. Carbonates and boric acid are then recovered as separate products.

Abstract: A method of converting radioactive alkali metal into a low level disposable solid waste material. The radioactive alkali metal is atomized and introduced into an aqueous caustic solution having caustic present in the range of from about 20 wt % to about 70 wt % to convert the radioactive alkali metal to a radioactive alkali metal hydroxide. The aqueous caustic containing radioactive alkali metal hydroxide and CO.sub.2 are introduced into a thin film evaporator with the CO.sub.2 present in an amount greater than required to convert the alkali metal hydroxide to a radioactive alkali metal carbonate, and thereafter the radioactive alkali metal carbonate is separated from the thin film evaporator as a dry powder. Hydroxide solutions containing toxic metal hydroxide including one or more metal ions of Sb, As, Ba, Be, Cd, Cr, Pb, Hg, Ni, Se, Ag and T1 can be converted into a low level non-hazardous waste using the thin film evaporator of the invention.

Abstract: A process for recovering alkali values from trona ore by partially dissolving trona in a first dissolving solution to form a first feed liquor and undissolved trona. The first feed liquor is cooled and sodium carbonate decahydrate is precipitated. The sodium carbonate decahydrate is recovered from the resultant first mother liquor that is returned as the first dissolving solution. The undissolved trona is further dissolved in a second dissolving solution to form a second feed liquor. The second feed liquor is preferably carbonated to convert sodium carbonate into sodium bicarbonate, and cooled to precipitate sodium bicarbonate. The sodium bicarbonate is recovered from the resultant second mother liquor that is returned as the second dissolving solution.

Abstract: A process for destroying alkali metal and alkaline earth metal-containing wastes, such as sodium, by feeding such waste into a molten bath containing a molten salt such as sodium carbonate, or a mixture of salts having a lower melting point, such as a mixture of sodium carbonate and an alkali metal halide, e.g. sodium chloride, or mixtures of alkali metal chlorides, feeding a mixture of carbon dioxide and oxygen into the molten salt bath and reacting the alkali metal or alkaline earth metal such as sodium in the waste with the carbon dioxide and oxygen to form alkali metal carbonate, e.g. sodium carbonate, in the molten salt bath.

Abstract: The present invention relates to a method and process for recovering solid sodium bicarbonate, from the effluent, of the cathode compartment of a diaphragm cell that contains sodium hydroxide and sodium chloride. The effluent is treated with carbon dioxide and ammonia to essentially convert the sodium hydroxide to sodium bicarbonate. Thereafter, the effluent is treated to decompose the ammonium chloride to evolve and recycle ammonia without the formation of pollutants, the treated effluent, free of NH.sub.3, CO.sub.2 and alkali, is resaturated and sent to the anode compartment of the diaphragm cell. In preferred embodiments, all of the steps are interconnected and the materials produced are recycled, such that the only products produced are chlorine, hydrogen and sodium bicarbonate, without waste products in a continuous process.

Abstract: Production of sodium bicarbonate from natural soda deposits that may occur as natural brines or solid soda salts is disclosed. The alkalinity in these natural soda deposits consists of carbonates and bicarbonates. The carbonates are converted to bicarbonates by reacting sodium carbonate with ammonium bicarbonate which acts as a carbon dioxide carrier until all the sodium carbonate is exhausted. The solubility of the sodium bicarbonate is lowered by the presence of non-alkaline sodium salts, e.g., sodium chloride. The regeneration of the cyclic reagent (NH.sub.3) is done using the sodium bicarbonate formed by the double decomposition of sodium chloride and ammonium bicarbonate giving a final soda free brine exempt of contaminants foreign to its original components.

Abstract: The present invention adds carbonates or chlorides of alkaline earth metals to the radioactive wastes containing sodium sulfate and subjects sulfate group in the radioactive wastes to reduction treatment, thereby converts the sulfate group into sulfides of alkaline earth metals which are chemically stable substances while suppressing SOx generation, and solidifies the radioactive wastes stably for an extended period of time by applying to the converted radioactive wastes solidifying treatment.

Abstract: The present invention is directed to an improved method for carrying out a exothermic chemical reaction with carbon dioxide in an aqueous environment. In the method, a fluid solution containing at least one chemical reactant which is exothermically reactive with carbon dioxide is provided. Liquid carbon dioxide is then injected into the solution of the chemical reactant at a pressure above the triple point of at least about 60 psig. The injection of the liquid carbon dioxide takes place under turbulent conditions wherein the liquid carbon dioxide expands to provide carbon dioxide vapor. The carbon dioxide vapor superheats to approach the exothermic reaction temperature which occurs between the carbon dioxide vapor and the chemical reactant. The chemical reactant and the carbon dioxide react in the dispersion exothermically to produce a chemical reaction product.

Abstract: A method for removing sodium polysulfide from used sodium/sulfur batteries provides that the cells are granulated under protective measures, the scrap is treated in a solution of sodium cyanide and the solution obtained is treated with air. The solution then contains sodium thiocyanate and sodium hydroxide, which latter can be reacted by means of CO.sub.2 to Na.sub.2 CO.sub.3, precipitated and separated.

Abstract: The method of the invention is advantageously applicable to realize a multistage chemical process during which liquid clarifiers suitable for the purification of water and sewage, furthermore, fine-disperse pulverulent solid products utilizable as pait pigments and fillers may be recovered. Each final product of the multistage chemical processes is a useful material, so the whole technology is waste free.

Abstract: The invention provides new processes for the production of precursor powders for ceramic materials by emulsion precipitation, the new processes permitting the economic production with at least some cations of uniformly small size particles (1 micrometer or less) to result in corresponding dense microstructures upon sintering the precursor powder to produce the ceramic material. The processes require the production of a fine water-in-oil type emulsion of an aqueous solution of the desired cation or cations in a non-miscible liquid, usually an oil, such as a saturated hydrocarbon, a suitable surfactant usually also being employed, The emulsion preferably has an aqueous particle size of 0.1 micrometer or less, produced by a mechanical emulsator. A gaseous reactant, preferably ammonia, or a mixture of ammonia with a neutral diluent gas, is bubbled through the emulsion to contact it and react with the cations, without breaking the emulsion by physical and/or chemical action.

Abstract: Sodium bicarbonate is produced by introducing solid sodium carbonate, sodium sesquicarbonate, and/or Wegscheider's salt into a reversion slurry, saturated with respect to bicarbonate and containing at least 10 wt. % solids, to effect rapid and complete conversion of the feed solids to crystalline sodium bicarbonate which is recovered from the slurry. Carbon dioxide is introduced into the reversion liquor to maintain its composition at a relatively constant value, preferably in a region of the Na.sub.2 CO.sub.3 --NaHCO.sub.3 --H.sub.2 O phase diagram that minimizes the equilibrium partial pressure of CO.sub.2 vapor above such liquor.

Abstract: Mined salt mixtures comprising sodium-carbonate, -bicarbonate, -chloride, -sulfate, and -double salts, such as trona and burkeite, are leached with a bicarbonate-saturated solution and added carbon dioxide to selectively dissolve the sodium chloride, sodium sulfate and burkeite and to precipitate additional trona, leaving a leach residue consisting essentially of trona. The trona is calcined and dissolved, and the carbonate solution is purified, crystallized and dehydrated in a non-convective solar pond yielding high purity sodium carbonate monohydrate which is converted into dense soda ash. The brine solution from the leach may be treated for the recovery of a further amount of trona.

Abstract: Methionine and potassium are recovered from the recycling solution of the potassium carbonate-methionine process by concentrating the mother liquor after the methionine precipitation and with cooling carbonating the mother liquor.

Abstract: A process for the production of sodium carbonate wherein sodium bicarbonate is recovered from a brine containing sodium carbonate by carbonation of the brine under controlled conditions. The sodium bicarbonate is crystallized from the carbonated brine in a multi-stage carbonating, cooling and crystallization process after which it is filtered to produce wet cake. The wet cake is subjected to predrying to provide a predried wet cake of a specified free moisture content and mixed with recycle light ash to provide a dryer feed of specified moisture content to alleviate problems of product fouling or plugging of the dryer. The light ash from the dryer then is bleached and subjected to recrystallization, screening, centrifuging and drying to provide a dried sodium carbonate possessing, after evaporation of the water of hydration and free moisture, less than 0.10 percent moisture and chemical and physical properties meeting commercial dense ash specifications.

Abstract: In the treating of waste slags produced in the desulfurization and/or dephosphorization of molten pig iron with alkali carbonates, the alkali is recovered by extracting said waste slags with hot water while feeding carbon dioxide gas to form an extraction solution having a pH of 9.0-11.5 and recovering alkali carbonates from said extraction solution. The extraction solution contains little sulphur and silicates, from which alkali carbonates can be easily recovered with high yield therefrom.

Abstract: A process for regenerating an ammonium, heavy metal salts, ammonium nitrate nd organic substances containing wash water resulting from the production of a hydrated oxide of an actinide which comprises evaporating said wash water to a concentration of at least 900 grams per liter salt and scrubbing the resulting CO.sub.2 -containing vapors with hot alkali lye prior to their condensation.

Abstract: Process for regenerating brines containing simultaneously sodium sulfites and sulfates so as to produce sulfur dioxide and an alkaline solution usable for absorbing sulfur dioxide, comprising contacting the brine with ammonium bisulfate, sodium bisulfate and ammonium sulfite to produce sulfur dioxide and an enriched solution of sodium sulfate and ammonium sulfate, which is reacted with CO.sub.2 and ammonia to obtain solid sodium bicarbonate which is decomposed to form CO.sub.2 and an enriched solution of ammonium sulfate, containing dissolved ammonium bicarbonate, which is heated with a reducing agent so as to decompose the ammonium sulfate to ammonia and ammonium bisulfate which is partly reduced to gaseous ammonia and sulfur dioxide, said process including several recycling steps.

Abstract: A method of treating an aqueous alkali metal sulfide-containing liquor to remove the sulfur values therefrom. Broadly, the method comprises introducing an alkaline liquor containing an alkali metal sulfide into a neutralization zone where it is intimately contacted and reacted with a sufficient amount of a gas containing a major amount of H.sub.2 S and a minor amount of CO.sub.2 to produce a product liquor of reduced alkalinity consisting essentially of a slurry of alkali metal bicarbonate and alkali metal bisulfide. The product liquor is withdrawn from the neutralization zone and introduced into a carbonation zone where it is contacted with a sufficient amount of a CO.sub.2 -containing gas to produce a product stream comprising a slurry of alkali metal bicarbonate crystals substantially free of alkali metal bisulfide and an H.sub.2 S-rich product gas containing a minor amount of CO.sub.2. The H.sub.

Abstract: An improved method for recovering spent sodium and sulfur components in sodium sulfite and sodium bisulfite pulping operations. The method involves reduction burning of spent liquor to convert it to smelt and the treatment of this smelt in a sequence of operations that accelerate the reaction steps used to produce sodium hydrosulfide, hydrogen sulfide, sulfur dioxide, sodium carbonate, sodium bicarbonate and to recover sodium sulfite, sodium bisulfite, sodium carbonate and/or sodium hydroxide while preventing formation of sodium thiosulfate.

Abstract: A method of removing and preferably recovering sulfur values from an alkali metal sulfide and carbonate mixture comprising the steps of (1) introducing the mixture in an aqueous medium into a first carbonation zone and reacting the mixture with a gas containing a major amount of CO.sub.2 and a minor amount of H.sub.2 S; (2) introducing the resultant product from step 1 into a stripping zone maintained at subatmospheric pressure, and contacting this product with steam to produce a gaseous mixture, comprising H.sub.2 S and water vapor, and a liquor of reduced sulfide content; (3) introducing the liquor of reduced sulfide content into a second carbonation zone, and reacting the liquor with substantially pure gaseous CO.sub.2 in an amount sufficient to precipitate bicarbonate crystals and produce an offgas containing CO.sub.2 and H.sub.

Abstract: A method for producing alkali carbonate crystals, including adding to an alkali carbonate and alkali hydroxide solution stream a 10 to 75 weight-% alkali hydroxide solution, charging the resulting mixture into a CO.sub.2 -containing gas whose temperature is from 150.degree. to 700.degree.C, collecting mixture remaining as liquid from the gas at the end of a residence time of mixture in gas of 0.1 to 10 seconds, separating alkali carbonate crystals from the collected mixture, and feeding the collected mixture, following the separating, back in the alkali carbonate and alkali hydroxide solution stream for another adding of alkali hydroxide solution.