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: Disclosed is a liquid fertilizer including: (i) an aqueous composition including ammonium thiosulfate; and (ii) a complex of a metal ion and a chelating agent, wherein the metal ion is selected from the group consisting of zinc, manganese, copper, iron, magnesium, calcium, potassium, and molybdenum. The complex lowers the freeze point of the aqueous composition when creating a liquid fertilizer including the ammonium thiosulfate and the complex. Optionally, the liquid fertilizer includes borate ions. Methods of using the liquid fertilizer are also disclosed.

Abstract: The invention relates to a process for preparing potassium thiosulfate, potassium sulfite or potassium bisulfite comprising the following steps: Step (1a): providing a potassium hydroxide or potassium carbonate solution for neutralizing acid forming components such as dissolving SO2 or H2S; Step (1b): providing an SO2 contacting solution, containing at least some potassium sulfite or potassium bisulfite or potassium thiosulfate; Step (2): providing SO2 gas; Step (3): reacting these to absorb the SO2 gas and to form an intermediate reaction mixture comprising potassium sulfite, or potassium bisulfite or a mixture thereof, and optionally recovering the potassium sulfite, or potassium bisulfite or a mixture thereof, and/or optionally using steps 4 and 5; Step (4): adding sulfur or sulfide containing compound containing sulfur having the oxidation state of 0, ?2 or of between 0 and ?2 to the reaction mixture and optionally potassium hydroxide or potassium carbonate, and reacting the mixture under suitable cond

Abstract: A process and system for hydrogen sulfide capture from gas streams employing an absorber vessel in which the gas stream containing hydrogen sulfide is contacted with an absorbent solution to remove the hydrogen sulfide from the gas stream. The process and system may further employ an oxidation vessel in which sulfides and/or bisulfides in the absorbent solution are oxidized to produce a thiosulfate and/or sulfate, yielding a solution that can be used as fertilizer or other applications.

Abstract: Provided herein are pharmaceutically acceptable sodium thiosulfate and pharmaceutical compositions thereof. Also provided herein are methods for determining the total non-purgeable organic carbon in a sodium thiosulfate-containing sample. Further provided herein are methods for producing pharmaceutically acceptable sodium thiosulfate. Still further provided herein are methods of treatment comprising the administration of pharmaceutically acceptable sodium thiosulfate.

Abstract: The invention is directed to a method for producing non-oxide semiconductor nanoparticles, the method comprising: (a) subjecting a combination of reaction components to conditions conducive to microbially-mediated formation of non-oxide semiconductor nanoparticles, wherein said combination of reaction components comprises i) anaerobic microbes, ii) a culture medium suitable for sustaining said anaerobic microbes, iii) a metal component comprising at least one type of metal ion, iv) a non-metal component containing at least one non-metal selected from the group consisting of S, Se, Te, and As, and v) one or more electron donors that provide donatable electrons to said anaerobic microbes during consumption of the electron donor by said anaerobic microbes; and (b) isolating said non-oxide semiconductor nanoparticles, which contain at least one of said metal ions and at least one of said non-metals.

Abstract: Provided herein are pharmaceutically acceptable sodium thiosulfate and pharmaceutical compositions thereof. Also provided herein are methods for determining the total non-purgeable organic carbon in a sodium thiosulfate-containing sample. Further provided herein are methods for producing pharmaceutically acceptable sodium thiosulfate. Still further provided herein are methods of treatment comprising the administration of pharmaceutically acceptable sodium thiosulfate.

Abstract: A method for treating hydrogen sulfide in a solution includes providing the solution containing hydrogen sulfide. The method also includes adding sodium nitrite to the solution in an amount suitable to react with the hydrogen sulfide and treat the hydrogen sulfide.

Abstract: Provided herein are pharmaceutically acceptable sodium thiosulfate and pharmaceutical compositions thereof. Also provided herein are methods for determining the total non-purgeable organic carbon in a sodium thiosulfate-containing sample. Further provided herein are methods for producing pharmaceutically acceptable sodium thiosulfate. Still further provided herein are methods of treatment comprising the administration of pharmaceutically acceptable sodium thiosulfate.

Abstract: Provided herein are pharmaceutically acceptable sodium thiosulfate and pharmaceutical compositions thereof. Also provided herein are methods for determining the total non-purgable organic carbon in a sodium thiosulfate-containing sample. Further provided herein are methods for producing pharmaceutically acceptable sodium thiosulfate. Still further provided herein are methods of treatment comprising the administration of pharmaceutically acceptable sodium thiosulfate.

Abstract: Processes for selectively eliminating hydrogen sulfide from liquid ammonia, either anhydrous or aqueous, are described herein. The processes generally include contacting a first liquid stream, anhydrous or aqueous, comprising ammonia and hydrogen sulfide, with a solution comprising sulfur dioxide to convert the hydrogen sulfide to thiosulfate.

Abstract: An efficient process for the continuous preparation of calcium thiosulfate (CaS2O3) from lime sulfur, through oxidation is described. The process involves oxidizing calcium polysulfide intermediate in a series of reactors to produce calcium thiosulfate as a clear liquid in high concentration with minimal byproducts. The process results in the complete destruction of polythionates, permitting the calcium thiosulfate produced to be useful in certain leaching processes for precious metals. The invention further makes it possible to recycle the process water from the leaching process for use as a raw material reactant in the process for calcium thiosulfate production.

Abstract: An efficient process for the continuous preparation of calcium thiosulfate (CaS2O3) from lime sulfur, through oxidation is described. The process involves oxidizing calcium polysulfide intermediate in a series of reactors to produce calcium thiosulfate as a clear liquid in high concentration with minimal byproducts. The process results in the complete destruction of polythionates, permitting the calcium thiosulfate produced to be useful in certain leaching processes for precious metals. The invention further makes it possible to recycle the process water from the leaching process for use as a raw material reactant in the process for calcium thiosulfate production.

Abstract: An efficient batch or semi-continuous method of production of relative high concentration, low byproduct-containing, calcium thiosulfate (CaS2O3) from lime, sulfur or calcium polysulfide, and sulfur dioxide under elevated reaction temperature conditions is described. The product is an emulsion of liquid calcium thiosulfate and solid byproducts. Under the conditions of the art, including the mole ratios of lime to sulfur, the temperature of the reaction process and the sulfur dioxide reaction conditions, including rate and duration, the byproducts are reduced to about 2% by weight.

Abstract: An efficient batch or semi-continuous method of production of relative high concentration, low byproduct-containing, calcium thiosulfate (CaS2O3) from lime, sulfur or calcium polysulfide, and sulfur dioxide under elevated reaction temperature conditions is described. The product is an emulsion of liquid calcium thiosulfate and solid byproducts. Under the conditions of the art, including the mole ratios of lime to sulfur, the temperature of the reaction process and the sulfur dioxide reaction conditions, including rate and duration, the byproducts are reduced to about 2% by weight.

Abstract: Method of cleaning a white load in a laundry machine, preferably a professional laundry machine, the method comprises subjecting the load to at least two washing steps and wherein the method comprises the steps of delivering bleach and subsequently a whitening additive.

Abstract: The present invention relates to a system and process utilizing ammonium thio sulfate solution (ATS) as the primary liquid absorption agent that is re-circulated through an SO2 Contactor/Absorber for high efficiency contacting and absorption of sulfur dioxide, SO2 from a combustion gas stream generated by incineration of a Claus Sulfur Recovery Unit (SRU) off gas stream (often referred to as a Claus tail gas stream) and also additional SO2 generated from incineration of additional sulfur containing streams. ATS is also re-circulated through a separate H2S Contactor/Absorber for absorption of and reaction with a Sour Water Stripper (SWS) off gas stream and additional H2S-Acid Gas (A.G.) streams to produce additional concentrated ATS. The process and equipment also provides the ability to readily switch between using ATS and ABS as the primary absorbent solution for SO2 absorption, depending upon the concentration of SO2 in the off gas feed streams.

Abstract: An efficient semi-continuous preparation of manganese thiosulfate (MnS2O3, MnTS) from manganese hydrosulfite and sulfur at elevated temperature is described. Manganese hydrosulfite is prepared from commercial manganese carbonate and sulfur dioxide. The resulting product is an emulation of liquid manganese thiosulfate and solid by-products. A manganese thiosulfate solution is produced according to the invention by use of certain mole ratios of MgCO3 to sulfur, and certain parameters such as the temperature of the reaction process and the pH conditions, including rate and duration of SO2 purging, which causes the by-products to be reduced to less than 2% by weight. The resulting manganese thiosulfate is a pinkish liquid with concentration up to 20%.

Abstract: Provided herein are pharmaceutically acceptable sodium thiosulfate and pharmaceutical compositions thereof. Also provided herein are methods for determining the total non-purgable organic carbon in a sodium thiosulfate-containing sample. Further provided herein are methods for producing pharmaceutically acceptable sodium thiosulfate. Still further provided herein are methods of treatment comprising the administration of pharmaceutically acceptable sodium thiosulfate.

Abstract: The present invention relates to a system and process utilizing ammonium thiosulfate solution (ATS) as the primary liquid absorption agent that is re-circulated through an SO2 Contactor/Absorber for high efficiency contacting and absorption of sulfur dioxide, SO2 from a combustion gas stream generated by incineration of a Claus Sulfur Recovery Unit (SRU) off gas stream (often referred to as a Claus tail gas stream) and also additional SO2 generated from incineration of additional sulfur containing streams. ATS is also re-circulated through a separate H2S Contactor/Absorber for absorption of and reaction with a Sour Water Stripper (SWS) off gas stream and additional H2S-Acid Gas (A.G.) streams to produce additional concentrated ATS. The process and equipment also provides the ability to readily switch between using ATS and ABS as the primary absorbent solution for SO2 absorption, depending upon the concentration of SO2 in the off gas feed streams.

Abstract: Process for the production of ammonium thiosulfate from gas streams comprising ammonia and hydrogen sulfide. One embodiment of the invention provides absorbing SO2 into a solution of ammonium sulfite and then contacting gaseous feed streams with portions of the resulting solution in a plurality of contact zones where portions of ammonium sulfite in the liquid streams are converted to ammonium thiosulfate upon contact with the gaseous feed streams.

Abstract: Fouling in basic washing systems such as caustic scrubbers can be prevented or at least mitigated by treating the liquid washing phase used in a caustic scrubber with an additive having at least one compound selected from the group consisting of oxalyl dihydrazide, a disulfite salt, isopropyl hydroxylamine, chlorobenzhydrazide, aminobenzhydrazide, a thiosulfate salt, 4,4-dimethyl oxazolidine, a hydrosulfite salt, and mixtures thereof.

Abstract: A process for continuous production of ammonium thiosulphate, (NH4)2S2O3 (ATS) from NH3, H2S and SO2 is disclosed. A first feed stream comprising H2O, H2S and NH3 with a molar H2S:NH3 ratio <0.4 is partially condensed to form a condensate. The condensate is contacted with a third feed gas comprising H2S and the gas stream comprising NH3 and H2S is passed to a mixing device where the gas stream is dissolved in water drained off from an aerosol filter. A second feed gas stream comprising approximately ? mole SO2 per mole of NH3 contained in the first feed stream is passed to a SO2 absorber. The aqueous solution produced in mixing device is contacted with the SO2 absorber.

Abstract: An efficient process to produce calcium thiosulfate (CaS2O3) from lime, sulfur and oxygen is described. By selecting appropriate process conditions such as mole ratios of lime to sulfur, temperature and pressure of the reaction process and the oxidation conditions, including rate and duration, the concentration of byproducts in the resulting suspension can be reduced to about 2% by weight or less. The solid particulate dispersion in the suspension tends to form a slimy solid suspension that is hard to filter if not treated properly. The suspension then can be acidified and treated with a flocculent. This agglomerates the solids into a floc that filters with ease. The resulting calcium thiosulfate is a clear liquid with concentrations achievable up to 29%.

Abstract: An efficient process for the preparation of magnesium thiosulfate involves reaction of magnesium hydrosulfite and sulfur at elevated temperature. Magnesium hydrosulfite can be prepared from commercial magnesium oxide and sulfur. Sulfur dioxide can be used to maintain pH. The resulting product is an emulsion of liquid magnesium thiosulfate and solid byproducts. Under controlled conditions, including mole ratios of MgO to sulfur, temperature of the reaction process, and pH, as well as rate and duration of SO2 purging, production of byproducts can be reduced to less than about 2% by weight. The magnesium thiosulfate solution can be prepared with concentrations of at least about 25%, preferably at least about 30%.

Abstract: An efficient process to produce calcium thiosulfate (CaS2O3) from lime, sulfur and oxygen is described. By selecting appropriate process conditions such as mole ratios of lime to sulfur, temperature and pressure of the reaction process and the oxidation conditions, including rate and duration, the concentration of byproducts in the resulting suspension can be reduced to about 2% by weight or less. The solid particulate dispersion in the suspension tends to form a slimy solid suspension that is hard to filter if not treated properly. The suspension then can be acidified and treated with a flocculent. This agglomerates the solids into a floc that filters with ease. The resulting calcium thiosulfate is a clear liquid with concentrations achievable up to 29%.

Abstract: A process for continuous production of ammonium thiosulphate, (NH4)2S2O3 (ATS) from NH3, H2S and SO2 comprising steps of:

Abstract: A method is provided for increasing the lifetime of Stretford solution by reducing or eliminating the generation of undesirable thiosulfate salts. The method has three major aspects. First, thiocyanate is added to the Stretford solution. Second, the concentration of sodium sulfate in the solution is maintained at a level below about 100 g/l. Third, the solution should contain little or no thiosulfate at the start of operations. It has been found that little or no thiosulfate is generated when the Stretford unit is operated under these conditions. The concentration of sodium sulfate in the solution is maintained at a level below about 100 g/l by removing sodium sulfate from the solution by cooling a slipstream of the solution to precipitate the sodium sulfate as Glauber's salt.

Abstract: A method is provided for producing thiosulfate from oxidation of reduced sulfur species without producing elemental sulfur and without converting more than 9% of the sulfur species to sulfate ion. The method consists essentially of oxidizing a thiosulfate solution with an oxidizing agent to produce a partially oxidized solution, adjusting the pH of the partially oxidized stream to between 5 and 8; and contacting the partially-oxidized solution with a stream containing a reduced sulfur species so that the reduced species is oxidized and the partially-oxidized stream reduced.

Abstract: A process is provided for the removal of hydrogen sulfide out of a gaseous stream (22), such as a natural gas, by contacting the hydrogen sulfide containing gas with a sorbing liquid (26) containing a tertiary amine so that the hydrogen sulfide is sorbed into the liquid in absorber (11) and transferring the sorbing liquid/hydrogen sulfide mixture to a reactor (15) where the tertiary amine promotes the conversion of the hydrogen sulfide into polysulfide via reaction with sulfur; transferring the polysulfide solution from the reactor (15) to a regenerator (10) where polysulfide is converted into elemental sulfur via reaction with air (9); transferring at least a portion of the solution (25) containing elemental sulfur, as well as sulfate and thiosulfate species, into a mixture (36) where it is contacted with gaseous ammonia which reacts with the sulfate and thiosulfate species to produce ammonium sulfate and ammonium thiosulfate which are removed from the solution while the remaining portion of solution (25) is

Abstract: A method for removing sulfur dioxide from flue gas and forming ammonium salts is described, along with a method for conversion of the ammonium salts into thiosulfate. Also described are an apparatus for absorbing sulfur dioxide from flue gas and an apparatus for converting ammonium salts into thiosulfate. The apparatus for absorbing sulfur dioxide from flue gas includes a multistage scrubber. The apparatus for converting ammonium salts into thiosulfate includes a fluidized bed reactor.

Abstract: A process for producing ammonium thiosulfate by contacting a feed gas containing hydrogen sulfide and ammonia with an aqueous absorbing stream containing ammonium sulfite and ammonium bisulfite to form an ammonium thiosulfate-containing solution; the absorption being controlled by monitoring the oxidation reduction potential of the absorbing stream and varying the feed rates in response to the oxidation reduction potential measurements. An ammonium bisulfide-containing aqueous stream is contacted with and absorbs sulfur dioxide to form an aqueous stream containing the ammonium sulfite and ammonium bisulfite reagents. This sulfite/bisulfite-containing stream is combined with the ammonium thiosulfate-containing solution in a vessel to produce a combined solution. A portion of the combined solution is recycled back to contact the feed gas and ammonium thiosulfate is recovered from the remaining portion of the combined solution.

Abstract: A process for production of ammonium thiosulphate (ATS) from H2S, NH3 and SO2, comprising producing ATS in a first absorption step by treating a first stream comprising H2S and NH3 with more than 0.3 mole H2S per mole NH3 with a solution containing ATS and ammonium sulphite, said solution being produced, in a second absorption step, by treating part of the solution from the first absorption step with a second gas stream gas stream comprising SO2. The second gas stream is obtained by combusting the H2S-containing off gas from the first absorption step supplemented with H2S-containing gas imported from other sources and/or by importing SO2-containing off gas streams from other souses. The content of NH3 in the off gas from the second absorber may be decreased by adding the equivalent amount of SO2 to the off gas upstream of an aerosol filter removing the NH3 and SO2 as a solution of NH4HSO3, which is fed to the first or second absorber, while the off gas from the filter is passed to the atmosphere.

Abstract: A process for producing ammonium thiosulfate wherein in a first reaction zone a feed gas mixture containing hydrogen sulfide and ammonia is contacted with an aqueous absorbing stream containing ammonium thiosulfite, ammonium bisulfite, and ammonium sulfite under conditions to limit conversion of sulfite to thiosulfate and produce an ammonia-rich absorbing stream, the unreacted hydrogen sulfide being rejected from the ammonia-rich absorbing stream, sulfur dioxide from a sulfur dioxide-containing gas stream being absorbed in the ammonia-rich absorbing stream in the absence of any substantial quantity of hydrogen sulfide, the ammonia-rich absorbing stream containing the sulfur dioxide being at least partially transferred to the first reaction zone, an aqueous product stream of ammonium thiosulfate being recovered.

Abstract: A process for continuous production of ammonium thiosulphate from H.sub.2 S, SO.sub.2, and NH.sub.3 comprising steps of producing in a first absorption step a solution of ammonium hydrogen sulphite by contacting a first gas stream comprising S0.sub.2 with NH.sub.3 and an aqueous solution comprising ammonium hydrogen sulphite in one or more absorbers connected in series and withdrawing a vent gas from one of the absorbers, passing the solution produced in the first absorption step to a second absorption step in which a second gas stream comprising H.sub.2 S is contacted with NH.sub.3 and an aqueous solution of ammonium thiosulphate thereby producing a solution being rich in ammonium thiosulphate.

Abstract: Ion exchange is used to make two grades of liquid fertilizer. In the first phase, ammonium thiosulfate (ATS) is contacted with a potassium-containing ion exchange resin to make the liquid fertilizer potassium thiosulfate (KTS) and an ammonium-containing resin. If operated under ambient temperatures, oxidation of any sulfites and the attendant formation of insoluble sulfates is avoided along with the associated fouling costs.The recharge line is operated in parallel to the KTS line. When the ammonium-containing resin is contacted with potassium chloride, the ammonium cations are exchanged for potassium cations and produce an ammonium chloride that can be used as a second liquid fertilizer. If desired, a concentrator can be used to remove water from each fertilizer to increase its concentration of KTS or ammonium chloride.

Abstract: A process is disclosed for treating lead paste from exhausted batteries. Calcium sulfite and calcium thiosulfite are formed by the reaction:3Ca(OH).sub.2 +4S.degree..fwdarw.2CaS+CaS.sub.2 O.sub.3 +3H.sub.2 O(1).The CaS and CaS.sub.2 O.sub.3 is reacted with sodium sulfate to effect the double exchange reaction:2CaS+CaS.sub.2 O.sub.3 +3Na.sub.2 SO.sub.4 .fwdarw.2Na.sub.2 S+Na.sub.2 S.sub.2 O.sub.3 +3CaSO.sub.4 (2).The sodium sulfide and sodium thiosulfate is then reacted with the lead paste for converting the various lead paste components (PbSO.sub.4, PbO and PbO.sub.2) into PbS with the concomitant production of sodium sulfate. The sodium sulfate can be recycled to reaction (2).

Abstract: A process for treating non-condensible gas streams containing H.sub.2 S, and for treating steam containing H.sub.2 S, is disclosed, the process being characterized by unique division of the noncondensible stream, or of a separated non-condensible H.sub.2 S-containing stream derived from the steam, with diverse oxidative treatment of the separated portions. The invention is particularly suited to treating the exhaust steam from a steam turbine which utilizes geothermal steam as the working fluid. In a preferred aspect, disposal of sulfur produced as normal byproduct of liquid oxidative steps may be reduced or avoided altogether by reaction of the sulfur with bisulfite and/or sulfite produced in the procedure to produce soluble thiosulfate.

Abstract: A method for white liquor oxidation in a kraft mill utilizes a two-stage selective oxidation system in which the first stage is operated to remove sulfide while the second stage is operated to oxidize a significant fraction of the remaining oxidizable sulfur compounds to sulfate. The resulting selectively oxidized white liquor products are used as alkali sources for various process steps in the mill. Optionally, white liquor can be oxidized in a single stage to convert a significant fraction of the oxidizable sulfur compounds to sulfate. Methods for controlling the selective oxidation process are disclosed.

Abstract: Solutions of an hydroxylamine or an at least partially neutralized hydroxylamine salt are stabilized against decomposition by adding thereto a water-soluble alkali metal, alkaline earth metal or ammonium thiosulfate.

Abstract: Geothermal steam is condensed with a sulfite solution to abate hydrogen sulfide. A portion of the hydrogen sulfide is converted in the condensation in the presence of soluble cationic polymeric catalysts to soluble sulfur compounds while avoiding elemental sulfur and carbonate formation. The remainder of the hydrogen sulfide is incinerated and the sulfur dioxide in the incinerator effluent is absorbed in an alkaline solution to form the sulfites for the geothermal steam condensation. By maintaining stoichiometric ratios, the hydrogen sulfide is substantially converted to soluble thiosulfate without the use of chelates, peroxides or makeup sulfites.

Abstract: The process comprises injecting into the inlet of a polyphase tubular reactor (6), on one hand, the aqueous solution at such temperature that the oxidation reaction occurs at a temperature between 50.degree. C. and 370.degree. C. and at an absolute pressure Pe of between 2 bars and 210 bars, and, on the other hand, gaseous oxygen at a pressure slightly higher than said pressure Pe. The invention is applicable to the treatment of effluents for the chemical destruction of pollutants.

Abstract: The present invention is directed to a process for removing H.sub.2 S from a gaseous stream, preferably a natural gas stream, which comprises forming a buffered aqueous H.sub.2 S stream containing thiosulfate by contacting the gaseous stream with water containing a buffering agent and thiosulfate to remove the H.sub.2 S from the other gases in the gaseous stream; introducing the buffered aqueous H.sub.2 S stream into a reduction section under conditions wherein elemental sulphur is produced and removing an effluent stream from the reduction section; introducing the reduction section effluent into an oxidation section and contacting the effluent with air to react the oxygen in the air with the H.sub.

Abstract: A process for the removal of hydrogen sulfide from sour gas or other gases produced upon the retorting of shale by the injection of an aqueous ammonia solution. Further, this process reduces the amount of arsenic present in product oil formed in the retort process.

Abstract: A process for recovering elemental sulfur from a hydrogen sulfide containing gas stream by reacting the hydrogen sulfide in the gas stream with a buffered aqueous solution enriched in thiosulfate ions at an initial pH between about 4.5 and 6.5 for residence time to sufficiently react a portion of the hydrogen sulfide to elemental sulfur. The elemental sulfur is then removed and the solution now lean in thiosulfate ions is regenerated by the oxidation of the remaining hydrogen sulfide in the gas stream to deplete the hydrogen sulfide from the gas stream and to regenerate the liquid solution for recycling to the reduction zone.

Abstract: A heat storage material is described which comprises a mixture of sodium sulfate decahydrate or sodium thiosulfate pentahydrate, and urea. The mixing ratio by mole of the sulfate decahydrate to urea is in the range of 1:1 to 1:3 and the mixing ratio by mole of the thiosulfate pentahydrate to urea is in the range of 1:2 to 1:8.

Abstract: A composition is provided which comprises an aqueous alkaline solution of a metal salt and black liquor, the metal salt being selected from the group consisting of iron, chromium, cobalt and nickel salts. This composition is useful in a process described for absorption of hydrogen sulfide from flue gas, followed by subsequent oxidation of dissolved sulfide to thiosulfate, if desired. The presence of the metal ions and black liquor synergistically catalyzes the overall reaction of absorption of hydrogen sulfide, followed by oxidation of the sulfide. Preferably, prior to scrubbing to remove hydrogen sulfide with the solution, the flue gas is first cooled to near its dew point, and then scrubbed with water to remove particulates. Additionally, the effluent flue gas from the absorption step is usefully scrubbed with water to recover heat, following which it is used to scrub condensates from a kraft pulp mill. The metal salt in the solution is preferably an iron salt at a concentration of about 0.002 M.

Abstract: A process for the manufacture of aqueous ammonium thiosulfate from sulfur dioxide wherein ammonium sulfite is formed as an intermediate product by the scrubbing reaction of ammonia with sulfur dioxide in the presence of water. Preferably, the ammonia is added to the sulfur dioxide in the bottom of the second scrubbing reaction vessel so as to maintain the sulfur dioxide and ammonia in liquid phase.

Abstract: Fluid streams containing hydrogen sulfide from a steam turbine or from a sour gas stream are contacted with an aqueous solution of a polyvalent metal chelate and an oxidizing agent whereby the hydrogen sulfide is converted to free sulfur and then to soluble sulfur compounds. The metal chelate is reduced to a lower oxidation state metal chelate and reduced metal chelate is subsequently oxidized with air back to the higher oxidation state and reused.

Abstract: A liquid melt becomes converted to crystalline form at a particular temperature either spontaneously or when artificially nucleated. The liquid releases heat at crystallization. If the liquid is in a supercooled state when it begins to crystallize, its temperature will rise from the particular temperature at which it is nucleated.Another liquid material is mixed with the liquid to be crystallized. The liquid additive has properties of forming a metastable solid together with the crystallizing material. When the liquid additive exsolves, the crystalline aggregate is weakened and is easily decomposed into fragments of small size. The liquid additive materials may include monohydric alcohols, diols and triols. The liquid additive material may be included in the liquid to be crystallized, in small amounts, amounts to two percent (2%) to five percent (5%) being typical.