Abstract: A process is described for minimizing accumulation of undesirable polythionates on an ion exchange resin used to recover uranium values from a leachate from an in situ mining operation by adding sulfite, either as a sulfite salt or as SO.sub.2, directly to the leachate or to the eluant.

Abstract: An ammonium thiosulfate product and method of making the same are provided in which the product is ammonium thiosulfate crystals with a film of water, i.e. about 80% to 90% ammonium thiosulfate with 10% to 20% water and preferably about 85% ammonium thiosulfate and 15% water at a pH of about 8 to 10, preferably about 9 and preferably produced by adding anhydrous ammonium thiosulfate to a 60% solution of ammonium thiosulfate or by vacuum separation of water from a 60% solution of ammonium thiosulfate to produce a product at about 80% to 90% ammonium thiosulfate.

Abstract: Precious metals such as gold and silver are recovered from difficult-to-treat ores, particularly those containing manganese, by lixiviating using an ammonium thiosulfate leach solution containing copper, sufficient ammonia to maintain a pH of at least 7.0, and at least 0.05% sulfite ion, sulfite and thiosulfate requirements being maintained by the reaction in situ of sulfur dioxide and elemental sulfur.

Abstract: This invention relates to a method of producing articles which generate heat at a substantially constant temperature for an extended period of time and which are able to remain in a stable state until such time as the generation of heat is desired. The method also relates to supercooled fluids produced by such methods. The method involves the processing of supercooled fluids such as hypo to produce this stable state. As a first step, a suitable material such as ethylene glycol may be added to the supercooled fluid to stabilize the supercooled fluid and to decrease the generation of heat in the supercooled fluid to obtain a desired temperature. The mixture is then heated to a relatively high temperature considerably above the melting temperature of the supercooled fluid. With the mixture at the high temperature, water is added to provide a particular specific gravity and an alkali is added to provide a particular pH.

Abstract: In the scrubbing of gases containing sulfur compounds with an aqueous alkaline solution of salts of anthraquinonedisulfonic acid, alkali sulfates are formed during a salt regeneration step, and these sulfates must be kept under a certain upper limit. This is accomplished by subjecting a partial stream of scrubbing solution to combustion under reducing conditions; however, thiosulfate is also removed, resulting ultimately in the decomposition of the anthraquinonedisulfonates. To overcome this drawback, the liquid product withdrawn from the combustion step is contacted with an oxygen-containing gas to convert alkali sulfides and/or alkali hydrogen sulfides contained therein to alkali thiosulfate, preferably in the presence of a catalytic amount of said salts of anthraquinonedisulfonic acid.

Abstract: A process is disclosed in which a waste gas containing sulfur compounds and carbon dioxide from pulp mill is contacted with an aqueous alkali solution derived from green liquor, white liquor or weak white liquor having low pH value and low sodium ion concentration and having been oxidized, whereby the sulfur compounds are absorbed as completely as possible with minimal absorption of carbon dioxide in the waste gas.

Abstract: An aqueous solution of ammonium thiosulfate, ammonia and at least one metal compound selected from the group consisting of the oxides and salts of copper, zinc and manganese provides a source of sulfur, nitrogen and micronutrient metals for fertilizer use.

Abstract: A process for purifying gases containing hydrogen sulfide and/or hydrogen cyanide is provided wherein said gases are contacted with an absorbing solution containing naphthols or their salts as a catalyst having a nitroso group at .alpha.-position or .beta.-position and also acidic group(s) and also having a standard redox potential in the range of 0.4 V or higher but lower than 0.7 V to remove hydrogen sulfide and/or hydrogen cyanide by converting the former mainly into thiosulfuric acid and the latter mainly into thiocyanic acid. According to this process, no trouble caused by sulfur deposit as seen in conventional method occurs, and the scale of purification apparatus is made smaller, and also the amount of catalyst required for purification is reduced. Further, by pretreating the absorbing solution, this process becomes more advantageous.

Abstract: Hydrosulfides of sodium, potassium, calcium, barium and strontium are prepared by reaction of the oxide or hydroxide of the metal with sulfur in aqueous medium at elevated temperature and pressure.

Abstract: An improved process for preparing a metallic sulphate in a reaction zone from mixing of the corresponding metallic sulphide concentrates with ammonium sulphate and heating. Heating preferably includes directly contacting the mixture with products of combustion of a heating fuel at temperatures between about 150.degree. C and about 480.degree. C. The products of combustion may be diluted with a gas, and the metallic sulphate of the corresponding metallic sulphide may be initially mixed with the mixture to inhibit the development of semi-fluid conditions in the reaction of the metallic sulphide concentrates with ammonium sulphate.

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: A process for the production of high purity calcium thiosulfate by a metathesis reaction of ammonium thiosulfate and calcium hydroxide or calcium oxide is disclosed. Aqueous solutions of high purity calcium thiosulfate, in concentrations up to about 30% by weight, are prepared by removing substantially all of the co-product ammonia under conditions which minimize the decomposition of the thiosulfate ion. Heating the reaction mixture to a temperature of about the boiling point at atmospheric pressure is used to prepare aqueous solution of about 10% by weight calcium thiosulfate, and lower reaction temperatures are employed to prepare more concentrated aqueous solutions of calcium thiosulfate up to about 30% by weight, which is the saturation point.

Abstract: A process is provided for reducing the requirement of fresh chemicals without increasing emissions in the pulping of cellulosic material with alkaline sodium- and sulfur-containing-sulfate pulping liquor, which comprises evaporating and burning spent sulfate pulping liquor to obtain a smelt; dissolving the resulting smelt in water to form a sodium-sulfide-sodium carbonate-containing solution green liquor; regenerating pulping white liquor containing sodium sulfide and sodium hydroxide from said green liquor; and recirculating said regenerated white liquor to the pulping stage; oxidizing at least one of the resulting green and white liquors to form sodium thiosulfate therein; reacting the oxidized liquor with residual acid liquor, from the manufacture of chlorine dioxide by reduction of an alkali metal chlorate solution, to convert thiosulfate to sulfur dioxide and sulfur; removing and recovering formed sulfur dioxide; and returning the residual liquor, freed from sulfur dioxide, to the pulping.

Abstract: A cyclic process is provided for utilizing sodium values in sulfate cellulose pulping, in which sodium losses normally are less than sodium additions to the process, thus tending to build up a sodium surplus, and which includes the steps of pulping cellulosic material with a pulping liquor comprising sodium hydroxide and sodium sulfide, separating spent pulping black liquor, evaporating and combusting the black liquor to recover sodium values as sodium sulfide and sodium carbonate, dissolving the sulfide and sodium carbonate in water to form green liquor, causticizing the green liquor with calcium hydroxide to form white liquor, and recycling white liquor to form pulping liquor, the improvement comprising maintaining sodium balance at least in part by removing sodium values as white liquor, oxidizing the white liquor with air at an elevated temperature, and utilizing the oxidized white liquor as a source of alkali in another cellulose pulp treatment process.

Abstract: In the production of anhydrous sodium dithionite by reacting sodium formate, an alkaline sodium compound and sulfurous acid anhydride in hydrous methanol, a process for treating the mother liquor, which comprises adding an alkali to the mother liquor left after the separation of the resulting anhydrous sodium dithionite to adjust its pH to at least 8, separating the solids precipitated, and oxidizing the filtrate with an oxidizing agent.

Abstract: In the production of anhydrous sodium dithionite by reacting sodium formate, an alkaline sodium compound and sulfurous acid anhydride in hydrous methanol, a process for treating the mother liquor, which comprises cooling the mother liquor left after the separation of the resulting anhydrous sodium dithionite to a temperature in the range of +5.degree. to -30.degree. C, and separating the precipitated sodium thiosulfate by filtration.

Abstract: Gas-liquid contact reaction efficiency in a two stage heavy black liquor oxidation process is improved by co-current contact in the first stage and countercurrent contact in the second stage or vice versa. Such improved efficiency is sustained by preventing the obstruction of gas discharge nozzles.

Abstract: Filtrate from a formate-sodium hydrosulfite preparation contains valuable amounts of sodium formate and sodium bisulfite, which are raw materials for the synthesis of sodium hydrosulfite. The filtrate also contains sodium thiosulfate which is a known catalyst for the decomposition of sodium hydrosulfite and, therefore, must not be introduced in with the raw materials. Accordingly the method concerns removing the sodium thiosulfate by means of ion exchange with a resin and directing the valuable sodium bisulfite and sodium formate effluent including methanol and water to a distillation column.

Abstract: A process for treating a hydrogen sulfide-containing gas in a closed loop system wherein said gas is passed through and absorbed by an alkaline aqueous absorbent containing an alkali carbonate and an oxidation catalyst. The solution containing the dissolved hydrogen sulfide is oxidized with an oxygen-containing gas to convert the absorbed hydrogen sulfide into elementary sulfur and sulfur salt compounds. After separation of the elementary sulfur from the solution, the solution is re-circulated for use as alkaline absorbent. A part of the re-circulated solution is diverted and subjected to mixed-combustion with an auxiliary fuel in a combustion furnace at an air ratio lower than 0.9 and at a temperature of 700.degree.C to 1100.degree.C to thermally decompose the sulfur compounds into hydrogen sulfide and an alkali carbonate.

Abstract: Crystallized ammonium thiosulfate is manufactured by converting ammonia with oxygen containing sulfur dioxide in ammonium thiosulfate solution to ammonium bisulfite and ammonium sulfite in a first step, while maintaining a pH of from 5.5 to 7.0 and a reaction temperature of up to 80.degree.C. In a second step, the ammonium bisulfite and ammonium sulfite in the solution are converted with ammonia and sulfur to ammonium thiosulfate.

Abstract: The dewatering capabilities of sulfite sludges from flue gas desulfurization facilities are substantially improved by the addition of relatively small amounts of sodium thiosulfate additive, or additives derived from or related to sodium thiosulfate, into the scrubber slurry liquor. As an added embellishment, these predetermined amounts of said additives are greater than those required for effecting substantial scale inhibition in the scrubber innards. Subsequently, conventional dewatering of the sulfite sludge to about 80 to 90 percent solids directly produces a waste product disposable in both an economically and an environmentally acceptable manner, in that the thixotropic characteristics of such sludges which are associated therewith upwards to about 70-percent solids therein are completely eliminated.