Abstract: Method and compositions are provided concerning stable supersaturated aqueous solutions of sparingly soluble inorganic salts. The method involves exceeding the solubility level of a sparingly soluable inorganic salt in water at ambient temperatures in the presence of polyanionic polyelectrolyte having a molecular weight of at least about 900 daltons and an ionic equivalent weight of not greater than about 65 and at least five ionizable groups per molecule. The solubility level may be exceeded by cooling a saturated solution of the sparingly soluble salt, preparing the sparingly soluble salt in situ, or adding a soluble salt having a common ion with the sparingly soluble salt to a concentrated or saturated solution of the sparingly soluble salt.

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: A method for production of absorptive particles of Wegscheider's Salt (Na.sub.2 CO.sub.3.3NaHCO.sub.3) having low bulk density and acceptable flow properties, by reaction of anhydrous sodium carbonate particles with water and carbon dioxide is disclosed. Particles of anhydrous sodium carbonate having a bulk density less than about 750 g/l are contacted with water up to 1.55 times the stoichiometric amount of water required for the formation of sodium carbonate monohydrate. Carbon dioxide is added in two stages; in the first, the reaction zone is maintained at ambient temperatures, the second, the reaction zone is preheated and the reaction temperature is maintained at between about 90.degree. and 105.degree. C. until at least about 50 weight percent Wegscheider's Salt is produced. Water is added to the carbon dioxide in the second stage if less than about 1.20 times the stoichiometric amount of water is added to the particles of anhydrous sodium carbonate in the first stage and when about 1.20 to 1.

Abstract: A process for removing sulfur oxides from exhaust gas formed by combustion particularly exhaust gas from an electricity-generating power plant. The exhaust gas flows through a reaction zone which operates like a spray dryer. A purifying liquor consisting of an aqueous solution of sodium carbonate and/or sodium bicarbonate is sprayed into the reaction zone, in which the heat content of the exhaust gases causes virtually all of the water content of the purifying liquor to be evaporated. The exhaust gas is subsequently passed through a filter. Anhydrous solids are withdrawn from the reaction zone and the filter and contain at least 75% of sodium sulfite, sodium sulfate and sodium chloride and are processed to form sodium carbonate. To that end the solids are dissolved and sulfite is oxidized to form sulfate so that a solution that contains sodium sulfate and sodium chloride is formed.

Abstract: Nahcolite-containing ore particles are separated from oil shale particles in a mixture of particles of nahcolite-bearing oil shale ore by irradiating the mixture of ore particles with electromagnetic energy in the infrared region of the spectrum and sorting the particles according to energy reflected at one or more selected wavelengths within that region to separate the nahcolite-containing ore particles from the oil shale particles.

Abstract: Sodium bicarbonate is produced in an apparatus comprising a reactor system for the production of sodium bicarbonate which comprises a housing having a plurality of reaction zones being placed in sequence from a last zone to a first zone, each being in liquid and gas flow communication with each adjacent zone; carbon dioxide inlet means being disposed at the bottom of the last zone so that carbon dioxide introduced into said last zone moves upwardly through said zone, and is discharged through a gas-liquid separator at the top of said zone and is then introduced into the bottom of the next adjacent zone, until said gas reaches the top of the first zone where it is discharged through a carbon dioxide gas outlet; inlet means for feeding an ammoniacal brine or a mother liquor to be carbonated into the top of the first zone, counter-currently to the upward movement of the carbon dioxide gas in said first zone, wherein said brine or mother liquor is passed downwardly through said first zone and flows sequentially i

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: A one-stage method for production of free-flowing, absorptive particles of Wegscheider's Salt (Na.sub.2 CO.sub.3 .multidot.3NaHCO.sub.3), having a low bulk density, low alkalinity and low friability, by reaction of higher bulk density, anhydrous sodium carbonate particles with carbon dioxide and steam at superatmospheric pressure is disclosed. Particles of high bulk density anhydrous sodium carbonate are introduced into a preheated reaction zone and heated to a temperature of at least about 100.degree. F., and thence continuously contacted therein with a gaseous mixture containing from about 45 to 70 weight percent steam and 30 to 55 weight percent carbon dioxide. By preheating the reaction zone and delaying the introduction of the gaseous mixture thereto until the temperature of the particles of sodium carbonate therein is at least about 100.degree. F., caking and coagulation of the contacted particles is substantially eliminated. The exothermic reaction mixtue is maintained at a temperature from about 240.

Abstract: Sodium thiosulfate is purged from a sulfur dioxide removal system involving contact of a sulfur dioxide-containing gas with a solution containing sodium sulfite to absorb sulfur dioxide from the gas. A portion of the liquid from a desorption zone containing a minor amount of sodium thiosulfate and a relatively large amount of sodium bisulfite, is treated to reduce the amount of water in the medium so that solids are precipitated from the liquid phase. The insolubles containing sodium sulfites are removed from the liquid. The liquid separated from the solids can be discarded and thereby purge thiosulfate more selectively with respect to other sodium salts. Also, the sodium values of the sodium thiosulfate-containing purge liquid can be recovered in active form by chemical reduction, and, preferably, carbonation. A sodium sulfate purge material from the absorption-desorption system can also be subjected to the chemical reduction system for further recovery of active sodium values.

Abstract: There is disclosed a process for reducing the loss of sodium values in a system for removing sulfur dioxide from a gas by the use of an absorption-desorption cycle employing aqueous sodium sulfite as the essential absorption solution. Sodium sulfate and/or sodium thiosulfate build-up in the system is avoided and the loss of sodium values reduced by subjecting sodium sulfate and/or sodium thiosulfate-containing material to chemical reduction to form a product containing a substantial amount of sodium carbonate. Preferably, the reduced product is subjected to carbonation followed by reaction of the bicarbonate and bisulfide components of the mixture to give a resulting liquid which is more suitable for use in the absorption-desorption process. By-product gases can be incinerated to produce sulfur dioxide-containing gases which can be charged to the sulfur dioxide absorption zone.

Abstract: The invention relates to a process for separating hydrogen sulphide from clarified green liquor, including precarbonating green liquor with a carbon dioxide rich gas, adding alkali bicarbonate to the precarbonated green liquor and stripping hydrogen sulphide therefrom forming simultaneously alkali carbonate, and preparing the alkali bicarbonate used in the process from the alkali carbonate formed. The process of the invention is carried out by performing the hydrogen sulphide stripping without crystallizing the alkali carbonate formed, preparing the alkali bicarbonate partly from alkali carbonate-alkali sulphide solution obtained in the precarbonation step and partly from the non-crystallized alkali carbonate solution, feeding at least a portion of the alkali carbonate -- alkali sulphide solution through the carbonation step, and passing the carbon dioxide rich gas first through the carbonation step and thereafter through the precarbonation step.

Abstract: Process and apparatus for producing bicarbonates by converting sodium hydroxide to sodium carbonate and reacting the sodium carbonate with carbon dioxide in a gas-liquid exchange and solid discharge zone and then in a gas-liquid exchange and solid discharge zone with cooling means, with possible recirculation, whereby bicarbonate is formed and precipitated in the first zone and bicarbonate formation is completed and precipitated in the second zone.

Abstract: A process is provided for converting potassium chloride to potassium bicarbonate with desirable conversions which bicarbonate can then be calcined to potassium carbonate. In one embodiment the potassium bicarbonate is formed in a reaction medium which is an admixture of water and a water miscible alcohol with the other reactants employed being carbon dioxide and an alkylamine. In a more preferred embodiment an alcoholic solution of an alkylamine which solution is saturated with carbon dioxide will be prepared and then an aqueous solution of a potassium halide, preferably potassium chloride, will be added to the alcoholic solution so as to form potassium bicarbonate.

Abstract: A continuous cyclic process for removing sulfur dioxide from gases produced in the combustion of fossil fuels or in chemical and metallurgical operations by means of an aqueous solution including the carbonate of an alkali metal to absorb said oxide out of said gases whereby the metal carbonate is converted into the metal sulfite. A two step recovery process is employed to reproduce the aqueous carbonate solution for reuse in the absorption step and to produce hydrogen sulfide which may be converted into elemental sulfur by well known means, if desired.

Abstract: Method for clarifying a carbonate process solution containing suspended insolubles which solution is used in the preparation of crystals selected from the group consisting of sodium bicarbonate, sodium sesquicarbonate, anhydrous sodium carbonate, and sodium carbonate monohydrate, which comprises dispersing in the carbonate process solution prior to crystallization a cationic flocculating agent comprising a substituted guar gum containing one quaternary ammonium group per 2 to 12 monosaccharide units to agglomerate the suspended insolubles so the suspended insolubles will readily settle out of the carbonate process solution.This invention relates to a process for clarifying a carbonate process solution used in the preparation of sodium bicarbonate, sodium sesquicarbonate, anhydrous sodium carbonate or sodium carbonate monohydrate crystals.

Abstract: This invention relates to a process for the treatment of the reaction mass produced during the joint elimination of barium-containing nitrite-/nitrate-bearing carburizing salt wastes and cyanide-/cyanate-bearing wastes by ignition of the dry mixture at elevated temperatures, comprising suspending the reaction mass in water and eitherA. neutralizing the alkaline suspension obtained with concentrated nitric acid to a pH value of 6, the feed velocity of the acid and conditions of agitation being so selected that the pH value of the suspension will at no time fall below pH 6, and separating the barium carbonate, orB. freeing the alkaline suspension obtained from barium carbonate, and neutralizing the filtrate with concentrated nitric acid to a pH value of 7.2, the feed velocity of the acid and conditions of agitation being so selected that the pH value of the suspension will at no time fall below pH 7.

Abstract: A method is shown for removing sulfur dioxide from a hot flue gas by absorption of the sulfur dioxide in an aqueous solution or slurry containing no more than 40 wt.% of an alkali metal carbonate or bicarbonate, preferably sodium carbonate and/or sodium bicarbonate using a spray-dryer scrubber to produce a dry mixture of sodium sulfite, sodium sulfate, and sodium carbonate and/or bicarbonate. Such a mixture is directly suitable as a feed to a regeneration stage.It is particularly preferred to regenerate the absorbent and recover commercial sulfur values in a closed-cycle process by next treating the solid absorption product in a molten salt reduction step with a reducing agent, preferably a carbonaceous material, to reduce the sodium sulfite and sulfate to sodium sulfide. Concurrently, a source of oxygen is fed to the reducer to generate sufficient heat therein for the reduction step by a combustion reaction.