Abstract: A method for removing sulfide from an aqueous alkali solution in which hydrogen peroxide is introduced into a sulfide-containing aqueous alkali solution associated with an alkali mineral recovery operation. The method is particularly useful for the processing of sulfide-containing aqueous alkali solutions containing NaHCO3 and Na2CO3, where bicarbonate in the sulfide-depleted alkali solution is decomposed to form Na2CO3, with concurrent evolution of gaseous carbon dioxide byproduct but without formation of gaseous H2S as a pollutant, and where Na2CO3 values are subsequently recovered from the sulfide-depleted carbonate-rich alkali solution via a crystallization operation.

Abstract: A method for removing sulfide from an aqueous alkali solution in which hydrogen peroxide is introduced into a sulfide-containing aqueous alkali solution associated with an alkali mineral recovery operation. The method is particularly useful for the processing of sulfide-containing aqueous alkali solutions containing NaHCO3 and Na2CO3, where bicarbonate in the sulfide-depleted alkali solution is decomposed to form Na2CO3, with concurrent evolution of gaseous carbon dioxide byproduct but without formation of gaseous H2S as a pollutant, and where Na2CO3 values are subsequently recovered from the sulfide-depleted carbonate-rich alkali solution via a crystallization operation.

Abstract: A flue gas desulfurization process in which a SO2-containing flue gas stream is contacted with a recirculating stream of an aqueous medium containing concentrated sulfuric acid and hydrogen peroxide, to yield a desulfurized flue gas stream and to produce additional sulfuric acid in the aqueous medium. A portion of the recirculating aqueous sulfuric acid stream is diverted for recovery of the additional sulfuric acid as gypsum in a neutralization step, and the process parameters are adjusted so that the heat of reaction generated during the neutralization step is sufficient to evaporate the free water that is present and yield a gypsum product that is substantially dry.

Abstract: Combustion flue gas containing SOX is treated to remove SOX using a dry particulate sorbent injection procedure in which a sodium-based sorbent precursor is calcined immediately prior to its introduction into the flue gas stream, to activate the sorbent for reaction with SOX. The sorbent precursor is a NaHCO3-containing compound, and trona is preferred as the sorbent precursor.

Abstract: A process for the production and recovery of crystalline sodium sesquicarbonate and of crystalline sodium carbonate monohydrate from aqueous liquors containing sodium carbonate and sodium bicarbonate. The crystalline products may optionally be heated or calcined to produce soda ash. The process is particularly suited for the recovery of soda ash from aqueous minewater streams obtained from solution mining of subterranean trona ore deposits.

Abstract: A process for the rapid production and stabilization of dilute aqueous peracetic acid in which acetic anhydride and hydrogen peroxide are reacted in an aqueous medium with a stoichiometric excess of hydrogen peroxide and the aqueous medium containing the peracetic acid reaction product is adjusted, as necessary, to a pH of less than about 8 to provide a stabilized dilute peracetic acid solution. The dilute peracetic acid may be produced on site or in situ for treatment of an aqueous medium requiring disinfecting, biocidal, antimicrobial or bleaching treatment.

Abstract: A flue gas desulfurization process in which a SO2-containing flue gas stream is contacted with a recirculating stream of an aqueous medium containing concentrated sulfuric acid and hydrogen peroxide, to yield a desulfurized flue gas stream and to produce additional sulfuric acid in the aqueous medium. A portion of the recirculating aqueous sulfuric acid stream is diverted for recovery of the additional sulfuric acid as gypsum in a neutralization step, and the process parameters are adjusted so that the heat of reaction generated during the neutralization step is sufficient to evaporate the free water that is present and yield a gypsum product that is substantially dry.

Abstract: A process for recovering sodium carbonate decahydrate crystals from solutions and mother liquors supersaturated in sodium bicarbonate concentration. Feed liquors containing higher levels of sodium bicarbonate than traditionally fed to a sodium carbonate decahydrate crystallizer are used to create a mother liquor within a sodium carbonate decahydrate crystallizer that is supersaturated with respect to sodium bicarbonate. Substantially pure sodium carbonate decahydrate crystals may be precipitated from the supersaturated mother liquor without substantially precipitation of sodium bicarbonate containing crystals.

Abstract: A method for converting sodium bicarbonate in a sodium carbonate monohydrate crystallization process to maintain a mother liquor composition in a sodium carbonate monohydrate crystallizer below the invariant point for the crystallizer for reducing or eliminating the cocrystallization of sodium sesquicarbonate crystals in the process. The mother liquor composition may be maintained below the invariant point by stripping carbon dioxide from a feed solution or from mother liquor recycled to the crystallizer.

Abstract: A process for recovering sodium carbonate decahydrate crystals from solutions and mother liquors supersaturated in sodium bicarbonate concentration. Feed liquors containing higher levels of sodium bicarbonate than traditionally fed to a sodium carbonate decahydrate crystallizer are used to create a mother liquor within a sodium carbonate decahydrate crystallizer that is supersaturated with respect to sodium bicarbonate. Substantially pure sodium carbonate decahydrate crystals may be precipitated from the supersaturated mother liquor without substantially precipitation of sodium bicarbonate containing crystals.

Abstract: A method for converting sodium bicarbonate in a sodium carbonate monohydrate crystallization process to maintain a mother liquor composition in a sodium carbonate monohydrate crystallizer below the invariant point for the crystallizer for reducing or eliminating the co-crystallization of sodium sesquicarbonate crystals in the process. The mother liquor composition may be maintained below the invariant point by stripping carbon dioxide from a feed solution or from mother liquor recycled to the crystallizer.

Abstract: A process is disclosed for converting dilute brines of sodium carbonate and sodium bicarbonate to form feed solutions from which sodium based chemicals may be recovered. The sodium bicarbonate in a dilute brine is neutralized and the brine then fortified with calcined trona to form a feed liquor concentrated in sodium carbonate from which sodium based chemicals may be recovered in a Monohydrate or other crystallization process.

Abstract: A process for the production of soda ash by withdrawing an aqueous mining solution containing dissolved sodium carbonate and at least about 1 wt % sodium bicarbonate from an underground alkali source; stripping CO2 gas from the withdrawn aqueous mining solution, to convert sodium bicarbonate dissolved therein to sodium carbonate; co-crystallizing sodium carbonate monohydrate and sodium sesquicarbonate by evaporation of water from the CO2-stripped aqueous mining solution, without co-crystallization of anhydrous sodium carbonate, to form a slurry of crystalline solids in an aqueous liquor; recovering crystalline solids from the slurry; and calcining the recovered crystalline solids to produce soda ash.

Abstract: A process for the production of soda ash by withdrawing an aqueous mining solution containing dissolved sodium carbonate and at least about 1 wt % sodium bicarbonate from an underground alkali source; stripping CO2 gas from the withdrawn aqueous mining solution, to convert sodium bicarbonate dissolved therein to sodium carbonate; co-crystallizing sodium carbonate monohydrate and sodium sesquicarbonate by evaporation of water from the CO2-stripped aqueous mining solution, without co-crystallization of anhydrous sodium carbonate, to form a slurry of crystalline solids in an aqueous liquor; recovering crystalline solids from the slurry; and calcining the recovered crystalline solids to produce soda ash.

Abstract: A process for the production of soda ash by withdrawing an aqueous mining solution containing dissolved sodium carbonate and at least about 1 wt % sodium bicarbonate from an underground alkali source; stripping CO2 gas from the withdrawn aqueous mining solution, to convert sodium bicarbonate dissolved therein to sodium carbonate; co-crystallizing sodium carbonate monohydrate and sodium sesquicarbonate by evaporation of water from the CO2-stripped aqueous mining solution, without co-crystallization of anhydrous sodium carbonate, to form a slurry of crystalline solids in an aqueous liquor; recovering crystalline solids from the slurry; and calcining the recovered crystalline solids to produce soda ash.

Abstract: The methods for decreasing scale formation in processes for the production of soda ash from trona or nahcolite ores are provided. Diphosphonic acid materials such as 1-hydroxy-ethylidene diphosphonic acid, 1-hydroxy-propylidene-1,-diphosphonic acid, 1-hydroxy-butylidene-1,-diphosphonic acid and 1-hydroxy-pentylidene-1,-diphosphonic acid have been found to diminish significantly the formation of magnesium scale in such processes.

Abstract: A process for producing valuable sodium-based chemicals from a brine containing sodium carbonate and sodium bicarbonate, such as those containing from about 8% to about 20% total alkali obtained by contacting water with an underground trona formation by heating the brine at about 100.degree. C. to about 140.degree. C. to evaporate water, convert sodium bicarbonate to sodium carbonate and to drive off resulting carbon dioxide, reacting the brine with reduced sodium bicarbonate with an aqueous sodium hydroxide solution in amounts to convert essentially all of the remaining sodium bicarbonate in the brine to sodium carbonate, cooling to about 5.degree. C. to about 25.degree. C. to precipitate sodium carbonate decahydrate crystals, separating the crystals from their mother liquor, melting the separate crystals to form a sodium carbonate solution, heating the solution to from above about 60.degree. C. to below 110.degree. C.

Abstract: A process is described for producing sodium-based chemicals from a brine containing sodium carbonate and sodium bicarbonate by heating the brine to evaporate water and drive off carbon dioxide and obtain a solution that will crystallize sodium sesquicarbonate, cooling the solution, precipitating sodium sesquicarbonate crystals and separating a first mother liquor from the sesquicarbonate crystals. The first mother liquor is then cooled to a lower temperature to precipitate sodium carbonate decahydrate crystals, the decahydrate crystals are separated from a second mother liquor and the decahydrate crystals are recovered for use in the manufacture of sodium-containing chemicals, such as sodium carbonate monohydrate, anhydrous sodium carbonate or soda ash.

Abstract: Beryllium is efficiently recovered from silicate ores in a hydrometallurgical, single solvent, process which avoids the complexities, high costs and hazards ofpyrolytic, fluorination and acid leach methods, by contacting the ore in a closed reactor at elevated temperature and autogenous pressure with a concentrated caustic solution and lime or lime hydrate to form a slurry containing dissolved beryllium, reducing the pressure to about one atmosphere and the temperature to below the boiling point of the caustic solution, separating by-product solids to leave a pregnant leach liquor, diluting and digesting the leach liquor to precipitate the beryllium and to leave a caustic mother liquor, and separating the beryllium. The caustic mother liquor can be recycled to the ore contacting step in a closed loop version of the process.

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.