Abstract: Disclosed herein are system and methods for producing a high purity ammonium sulfate product as well as either a lower or a high purity calcium carbonate product by reacting flue gas desulfurization (FGD) gypsum feedstock in batch or continuous mode using synthesized ammonium carbonate from ammonia and carbon dioxide gases. The high purity calcium carbonate is obtained by using a precipitation catalyst, filtering out the impurities, then precipitating a high purity calcium carbonate. Alternatively, the lower purity calcium carbonate may be dissolved in acid, impurities filtered out, then a high purity calcium carbonate is precipitated out using a soluble carbonate salt.

Abstract: A method for complex treatment of phosphogypsum comprising crushing of phosphogypsum and its washing with a solution of sulphuric acid, concentration 2-15%, and stirring at 50-80? C.

Abstract: A composition includes calcium sulfate hemihydrate, stearic acid, an accelerant, and a mixing solution. The composition can be injected, e.g., through a needle, and is capable of setting, e.g., in vivo, in a relatively short period of time to a relatively high hardness.

Abstract: A continuous countercurrent flow process for converting FGD gypsum to ammonium sulfate and calcium carbonate including countercurrent flows with internal recycle of liquids to maximize the purity of reaction products while minimizing reaction times, and further include embodiments of the process that provide a yield of both ammonium sulfate and calcium carbonate to be 97 to 100%, and embodiments that provide for processes having a total time of reaction being 8 to 12 minutes, the invention further including processes for removing contaminants from the FGD gypsum employing an acid rinse process and/or a slurry tank reactor process.

Abstract: A composition includes calcium sulfate hemihydrate, stearic acid, an accelerant, and a mixing solution. The composition can be injected, e.g., through a needle, and is capable of setting, e.g., in vivo, in a relatively short period of time to a relatively high hardness.

Abstract: An aqueous precipitation process for the preparation of particles comprising primarily silver sulfate, comprising reacting an aqueous soluble silver salt and an aqueous soluble source of inorganic sulfate ion in an agitated precipitation reactor vessel and precipitating particles comprising primarily silver sulfate, wherein the reaction and precipitation are performed in the presence of an aqueous soluble organo-sulfate or organo-sulfonate additive compound, the amount of additive being a minor molar percentage, relative to the molar amount of silver sulfate precipitated, and effective to result in precipitation of particles comprising primarily silver sulfate having a mean grain size of less than 50 micrometers.

Abstract: A catalyst of a water insoluble vanadyl sulfate or a complex catalyst, in which a specific oxide and a specific sulfate are combined to the water insoluble vanadyl sulfate are excellent not only in their activity, durability and SO2 resistance, not only in substantially no oxidization of SO2 to SO3 as in HCl resistant. Therefore, using this catalyst, a decomposition treatment of an organic halide(s) can be carried out with high efficiency and good stability. In particular, a efficient decomposition treatment of an organic halides(s) can be carried out also in the cases that dust is coexist; the gas to be treated contains SOX or HCl; or they generate in the decomposition area.

Abstract: Methodology for formulating sodium bicarbonate and potassium sulfate. In one embodiment, sodium sulfate and ammonium bicarbonate are reacted to form sodium bicarbonate with the remaining liquor or brine treated with sulfuric acid to remove carbonates with subsequent precipitation of potassium sulfate. A further embodiment employs ammonium bicarbonate, ammonia gas or carbon dioxide to precipitate sodium bicarbonate. The result of the methods is the production of high quality fertilizer and food grade sodium bicarbonate.

Abstract: System for removal of targeted pollutants, such as oxides of sulfur, oxides of nitrogen, mercury compounds and ash, from combustion and other industrial process gases and processes utilizing the system. Oxides of manganese are utilized as the primary sorbent in the system for removal or capture of pollutants. The oxides of manganese are introduced from feeders into reaction zones of the system where they are contacted with a gas from which pollutants are to be removed. With respect to pollutant removal, the sorbent may interact with a pollutant as a catalyst, reactant, adsorbent or absorbent. Removal may occur in single-stage, dual-stage, or multi-stage systems with a variety of different configurations and reaction zones, e.g., bag house, cyclones, fluidized beds, and the like. Process parameters, particularly system differential pressure, are controlled by electronic controls to maintain minimal system differential pressure, and to monitor and adjust pollutant removal efficiencies.

Abstract: This invention provides a process of making a palladium replenisher comprising a complex of palladium tetraammine sulfate. The process includes distilling a palladium nitrate solution at a temperature maintained at or below about 115° C. Palladium sulfate and ammonium hydroxide are then added to make the palladium tetraamine sulfate replenisher from solution. The replenisher of the invention is used to replenish depleted palladium during palladium electroplating to maintain the palladium concentration in the bath within from about 5 to about 10 weight percent of recommended plating bath levels.

Abstract: Apparatus, materials, and methods for removing ammonia from fluids using metal hydroxides (e.g. zinc hydroxide) and metal loaded media (e.g. zinc loaded ion exchange resins); the metal hydroxides and metal loaded media may be regenerated with a weak acid (pKa between 3 and 7). Alternatively, ammonia is removed from fluids by using H2SO4 and ZnSO4 and metal loaded media; the metal loaded media may be regenerated with H2SO4 and ZnSO4; the ammonia containing H2SO4 and ZnSO4 may be concentrated as necessary to form (NH4)2SO4.ZnSO4.6H2O (ammonium zinc sulfate hexahydrate) crystals. These crystals are removed from the mother liquor and heated to temperatures exceeding 200° C. releasing NH3 and H2O vapor upon the decomposition of the crystals.

Abstract: Spent potliner from aluminum reduction cells is treated, for example, with sulfuric acid to recover carbon, silica and alumina or to recover a vitrified product of silca and alumina.

Abstract: A process is provided for recovering sodium bicarbonate and ammonium sulfate from a solution containing sodium sulfate derived from a process for removing sulfur contaminants out of a gas with sodium bicarbonate reagent. Sodium bicarbonate is precipitated and removed from the solution. Sodium sulfate or ammonium bicarbonate is added to the solution to form a second precipitate of sodium bicarbonate, which is removed from the solution. The solution is conditioned by either heating the solution to 95.degree. C. to liberate ammonia and carbon dioxide or by adding sulfuric acid to the solution to decompose any carbonates. The solution is cooled to a temperature between -2 to 2.degree. C. to form a third precipitate of sodium bicarbonate. Sulfuric acid is added to the solution to decompose any carbonate minerals, and purified ammonium sulfate solution is recovered.

Abstract: A process for producing sodium bicarbonate and sodium carbonate. The process includes reacting within a reactor sodium sulfate in aqueous solution with ammonia and carbon dioxide to precipitate sodium bicarbonate and form a first mother liquor. The sodium bicarbonate is separated and dried to produce sodium bicarbonate product. Alternatively, the sodium bicarbonate may be calcined to convert it to sodium carbonate. The first mother liquor may be evaporated to precipitate unreacted sodium sulfate, with the formation of a second mother liquor. The second mother liquor may be cooled to precipitate a double salt of sodium sulfate/ammonium sulfate and water. A third mother liquor is formed from this process. The latter-mentioned liquor from the precipitation of the double salt is evaporated to precipitate a substantial pure ammonium sulfate in a purity of greater than approximately 75 wt %. A fourth mother liquor is formed.

Abstract: There is disclosed a process for recovering sodium bicarbonate and forming ammonium sulfate from a source containing sodium sulfate. The method involves contacting the sodium sulfate in solution with carbon dioxide and a compound containing ammonia. Sodium bicarbonate is precipitated in high purity from the solution. It is important to maintain the temperature of the source solution at or above 32.degree. C. This provision eliminates contamination of hydrates or ammonium bicarbonate components. The filtrate of the sodium bicarbonate reaction can be further processed to yield an ammonium sulfate product in the concentrated liquid or precipitated form in high purity. The basic process can be expanded to be combined with a conventional Claus process for sulphur recovery as a Tail Gas Unit, combined with lime injection to result in gypsum precipitation or can be further employed in a wet scrubbing process for FGD schemes.

Abstract: Process for using reactions of gas/solid type in which the solid reactant contains an at least partially hydrated salt.The process makes it possible to shift the position of the equilibrium line of the reaction under consideration and to reduce its slope in a Clapeyron diagram so as to cover a wider temperature region for a limited pressure range.

Abstract: A liquid oxidizing system has a closed circuit in which a liquid containing matter to be oxidized is circulated. The circuit is provided with an ejector for forming a jet stream of the liquid into which oxygen, or both oxygen and an oxidizing catalyst are supplied. The oxygen (and the catalyst) rapidly contacts the matter to be oxidized in the jet stream and oxidizes it. The system is not only applicable to the treatment of waste water, such as from factories, but also useful for making a product by oxidizing a liquid, e.g. iron polysulfate which is a good coagulant.

Abstract: A novel basic composite metal sulfate fiber, a process for the production thereof, and a resin and/or rubber composition which contains the basic composite metal sulfate fiber and gives a molded article which is improved in mechanical strength and/or flame retardancy and having an excellent appearance. The basic composite metal sulfate fiber has the formula (1),(Mg.sub.1-x M.sup.2+.sub.x).sub.6 (OH).sub.12-2y (SO.sub.4.sup.2-).sub.y.mH.sub.2 O (1)wherein M is at least one metal selected from the group consisting of Mn, Fe, Co, Ni, Cu and Zn, and x, y and m are respectively defined by 0.005<x<0.5, 0.8<y<1.2 and 0<m<4.

Abstract: Disclosed is a method for preparing high purity alunite. In the method, a material selected from the group consisting of sodium sulfate, sodium bisulfate, ammonium sulfate, ammonium bisulfate, potassium sulfate and potassium bisulfate is provided and reacted with a source of aluminum hydroxide in a liquid. The reaction is carried out under acidic conditions, and alunite is recovered after separating, washing and drying.

Abstract: The process of the invention is carried out in gaseous phase by the action of ammonia on the aqueous solutions of iron salts in an appropriate reacting vessels.

Abstract: The invention concerns processes for the preparation of zirconium compositions which on calcination form zirconia. The zirconium compositions are prepared by the addition of an ammonia source to an aqueous zirconium sulfate solution to give a solution pH in the range of from 0.1 to 2.5 and preferably 1.0 to 2.0. The zirconium composition precipitated from solution appears crystalline, is readily collected by filtration and has low levels of metallic impurities. Therefore, the process of the invention may be used to advantage in the purification zirconium compounds.The invention also includes the zirconium compositions and processes for the purification of zirconium compounds including zirconia.

Abstract: A process for the granulation of potash salts to produce granules in high yield by the steps of mixing the potash salt with an inorganic phosphate binder and water, granulating the mixture and drying it.

Abstract: A process is described for the simultaneous removal of H.sub.2 S and ammonia from gaseous streams containing other acid and basic gases. The process comprises closed loop scrubbing of the gaseous stream with a copper sulfate-ammonium sulfate solution to yield a copper sulfide precipitate, concurrent neutralization of the acidity generated in the scrubbing step by addition or scrubbing of ammonia and other basic gases, separating the precipitate, hydrothermally leaching the precipitate with oxygen or air under controlled temperature and pressure to reoxidize the sulfide to copper sulfate, recycling the copper sulfate to the scrubber, and rejecting sulfur from the system in the form of (NH.sub.4).sub.2 SO.sub.4.

Abstract: Ammonium jarosite is converted to hematite or magnetite and ammonium sulphate. The invention can be used for removing iron from a feed solution containing dissolved ferrous sulphate. The feed solution is treated with ammonium sulphate and oxygen to precipitate ammonium jarosite which is then separated from the treated solution to produce an ammonium jarosite slurry and a separated solution containing sulphate ions. The ammonium jarosite slurry is treated with ammonia to convert the ammonium jarosite to hematite or magnetite and ammonium sulphate solution. The ammonium sulphate solution is separated from the hematite or magnetite, and a portion of the separated ammonium sulphate solution is recycled to the ammonium jarosite precipitation step, the remaining portion of the separated ammonium sulphate solution being recovered.

Abstract: A soil modifier comprising from 80 to 95% by weight of a mixture of ferric oxide and ferric sulphate in an oxide/sulphate weight ratio of from 0.25:1 to 1:1, is prepared by calcining at 500.degree.-600.degree. C in an oxidizing atmosphere a blend of by-product obtained in the manufacture of titanium oxide by the sulphate process, with at least 20% by weight with respect to said by-product, of a material based on ferric sulphate and/or ferric oxide. Calcining is then continued under the same conditions, replacing said material in the blend continuously fed in by a recycle fraction of the product continuously discharged.

Abstract: Novel compositions for use in agriculture as soil improvers and fertilizers comprising as essential components ammonium sulfate and ferric oxide hydrate. By-products obtained in the production of titanium dioxide from ilmenite or ilmenite slag in the sulfate process and substantially consisting of ferrous sulfate heptahydrate are reacted with ammonia and that the reaction product obtained, consisting substantially of ammonium sulfate and ferrous hydrate, is subsequently oxidized until a composition is obtained which substantially consists of ammonium sulfate and ferric oxide hydrate.

Abstract: A soil modifying composition and a concentrated solution of ammonium sulphate with a high purity degree are obtained from by-products consisting essentially of ferrous sulphate heptahydrate, obtained in the production of titanium dioxide from ilmenites by the sulphate process, by contacting solid particles of said by-products with gaseous ammonia, lixiviating the resulting product with water, thereby to recover said concentrated solution of ammonium sulphate, the dried residual solid yielding said soil modifying composition.

Abstract: Soil modifiers comprising from 80 to 95% by weight of a mixture of ferric oxide and ferric sulphate in an oxide/sulphate weight ratio of from 0.2:1 to 2:1 are prepared by calcining at 500.degree.-600.degree. C in the presence of an oxidizing gas a material consisting essentially of ferrous sulphate with an average number of molecules of crystallization of from 1 to 5 obtained by partial dehydration of the waste materials, consisting essentially of ferrous sulphate heptahydrate, obtained in the manufacture of titanium dioxide from ilmenites or ilmenite slags by the sulphate process. These modifiers are particularly suitable for clay soils.

Abstract: Process for insolubilizing water soluble wastes from alkaline sodium or ammonium type sulfur dioxide control systems used in conjunction with industrial or power plants. The sodium or ammonium sulfite or sulfate wastes are reacted in solution with ferric ions and sulfuric acid to produce an insoluble basic, hydrous or anhydrous, sodium and/or ammonium hydroxy ferric sulfate or sulfite compounds of the generic type M.sub.v (Na, NH.sub.4).sub.w Fe.sub.x (SO.sub.u).sub.y (OH.sub.z)nH.sub.2 O, wherein M is selected from an alkali metal other than sodium, or an authigenic metal or other cation present in industrial or power plant wastes, v is selected from zero to six, w is selected from zero to five, x is selected from zero to six, y is selected from one to five, u is 3 and/or 4, z is selected from zero to 12, and n is selected from zero to 20. Principal end product compounds include Natrojarosite, Ammoniojarosite, Metasideronatrite, Sideronatrite, Depegite, Rosarite, Iriite, and mixtures thereof.

Abstract: A solution of sodium sulfite or sulfide is reacted with ammonium sulfate, so as to produce a gas containing SO.sub.2 or H.sub.2 S, NH.sub.3 and H.sub.2 O, which is thereafter treated for sulfur production and NH.sub.3 recovery, and a liquid outflow containing sodium sulfate which is reacted with CO.sub.2 and NH.sub.3, in order to produce NaHCO.sub.3 and regenerate the ammonium sulfate. NaHCO.sub.3 may be converted to sodium carbonate and CO.sub.2, the latter being re-used in the process.

Abstract: Compositions useful in agriculture as soil modifiers and fertilizers are prepared by contacting the waste materials, obtained in the manufacture of titanium dioxide from ilmenites by the sulphate process, and which consist essentially of ferrous sulphate, with oxides, hydroxides or carbonates of alkali metals or alkaline earth metals or ammonium carbonate, and then submitting the reaction product to oxidation to convert the ferrous hydroxide into ferric hydroxide. Ferric hydroxide is further converted to ferric sulphate by treatment with sulphuric acid.