Abstract: This invention relates to production of an aqueous solution containing ammonium thiosulfate from a feed gas containing hydrogen sulfide (H2S) and ammonia (NH3). Sufficient separation of feed gas H2S from NH3 is achieved by controlling individual NH3 and H2S absorption mass-transfer rates in a single co-current stage, whereby a first gas contacts a first liquid containing ammonium bisulfite (ABS). Substantially more NH3 is absorbed than H2S, converting ABS to diammonium sulfite (DAS). A portion of DAS reacts with a sufficiently small portion of H2S to produce ATS and leaves as a second liquid stream. A larger portion of H2S leaves as a second gas stream. The second gas stream is oxidized to sulfur dioxide (SO2) comprising a third gas stream. The third gas stream contacts the second aqueous stream in a second contact stage whereby DAS in the second liquid stream is converted to ABS and returned to the first contacting zone.

Abstract: This invention relates to production of an aqueous solution containing ammonium thiosulfate from a feed gas containing hydrogen sulfide (H2S) and ammonia (NH3). Sufficient separation of feed gas H2S from NH3 is achieved by controlling individual NH3 and H2S absorption mass-transfer rates in a single co-current stage, whereby a first gas contacts a first liquid containing ammonium bisulfite (ABS). Substantially more NH3 is absorbed than H2S, converting ABS to diammonium sulfite (DAS). A portion of DAS reacts with a sufficiently small portion of H2S to produce ATS and leaves as a second liquid stream. A larger portion of H2S leaves as a second gas stream. The second gas stream is oxidized to sulfur dioxide (SO2) comprising a third gas stream. The third gas stream contacts the second aqueous stream in a second contact stage whereby DAS in the second liquid stream is converted to ABS and returned to the first contacting zone.

Abstract: Provided is a method for high concentration cation exchange metathesis of divalent ions such as calcium with univalent ions such as sodium or potassium. Due to the difference between ionic valences between the exchanged ions, the provided process behavior is strongly dependent upon the selection of resin properties and to total solution normality. A combination of resin properties and solution normality is provided to achieve the cation exchange.

Abstract: Provided is a method for high concentration cation exchange metathesis of divalent ions such as calcium with univalent ions such as sodium or potassium. Due to the difference between ionic valences between the exchanged ions, the provided process behavior is strongly dependent upon the selection of resin properties and to total solution normality. A combination of resin properties and solution normality is provided to achieve the cation exchange.

Abstract: Provided is a method for high concentration cation exchange metathesis of divalent ions such as calcium with univalent ions such as sodium or potassium. Due to the difference between ionic valences between the exchanged ions, the provided process behavior is strongly dependent upon the selection of resin properties and to total solution normality. A combination of resin properties and solution normality is provided to achieve the cation exchange.

Abstract: Methods for producing cyanide salts using a metathesis process using ion exchange to facilitate a double-decomposition reaction where components of a cyanide-containing compound are exchanged to produce a cyanide salt product are provided. In one embodiment of the invention, HCN may be converted to an alkali salt using a base. The alkali cyanide salt undergoes ion-exchange to yield the desired cyanide salt product. In another embodiment of the invention, hydrogen cyanide is directly converted to cyanide salts in an ion exchange bed without first being converted to a basic salt.

Abstract: Methods for producing cyanide salts using a metathesis process using ion exchange to facilitate a double-decomposition reaction where components of a cyanide-containing compound are exchanged to produce a cyanide salt product are provided. In one embodiment of the invention, HCN may be converted to an alkali salt using a base. The alkali cyanide salt undergoes ion-exchange to yield the desired cyanide salt product. In another embodiment of the invention, hydrogen cyanide is directly converted to cyanide salts in an ion exchange bed without first being converted to a basic salt.