Abstract: Provided is a semiconductor doped with an increased binding energy hydrogen species and a method of making the doped semiconductor.

Abstract: This patent describes the use of barium sulfate as filler for thermosetting and thermoplastic plastics, elastomers, sealants, adhesives, fillers, varnishes, paints, paper, glass and as substrate for colored pigment formulations as well as for single-layer or multilayer coatings consisting of metal oxides, metal oxide mixtures and/or metal compounds, as a nucleus of crystallization for lead sulfate in the negative electrode paste of lead accumulators and as an X-ray contrast medium, the barium sulfate being produced by a continuous process wherein a barium salt solution and a sulfate solution are simultaneously and continuously brought together in equimolar quantities in a precipitating suspension at a temperature of 30 to 90° C., with constant stirring, the precipitating suspension is withdrawn continuously in a steady volume and the barium sulfate precipitate is filtered, washed and optionally dried, wherein the barium salt solution has a concentration of 0.1 to 0.

Abstract: This invention provides a production process, which can stably produce high-quality satin white (calcium trisulfoaluminate) having very small and homogeneous particulate shapes suitable for incorporation into coated paper for printing, and an apparatus for use in said process. In this process for producing calcium trisulfoaluminate, a calcium hydroxide suspension (A) is reacted with an aqueous aluminum sulfate solution (B) to produce calcium trisulfoaluminate (C). The aqueous aluminum sulfate solution (B) is added in plurality of stages to the calcium hydroxide suspension (A). At least any one stage of the plurality of stages addition, addition of the aqueous aluminum sulfate solution (B) to the calcium hydroxide suspension (A) is carried out in such a manner that the aqueous aluminum sulfate solution (B) is continuously added to the calcium hydroxide suspension (A) being continuously transferred.

Abstract: Methods of reducing smoke levels in smoke-affected areas, reducing the level of toxic compounds produced by fires, fire suppression, and increasing flame retardancy. In particular, methods according to the present invention comprise dispersing nanocrystalline particles in the areas affected by smoke for sorption of smoke particulates and toxic compounds produced from a fire. The nanocrystalline particles are also effective for use in methods of fire suppression and flame retardancy.

Abstract: The present invention is directed to the microwave treatment of a class of selected metal ores and concentrates, particularly those known as chalcopyrite, in a fluidized bed reactor. The end product is commonly a mixture of copper oxide and copper sulfate, both of which are liquid soluble and directly recoverable by known techniques. The ratio of the oxide-sulfate mixture end product may be controlled by suitable control of microwave parameters.

Abstract: Agents for surface treatment which can impart excellent corrosion resistance to zinc or zinc alloy products at low cost. The agents for the surface treatment of zinc or zinc alloy products of this invention include at least one water-soluble compound which contains antimony, bismuth, tellurium or tin. Ideally, a nickel salt and/or a manganese salt is also included, and most desirably tannins and/or thioureas are also included. Ideally, the zinc or zinc alloy products which have been immersed and treated in an aqueous solution which contains these agents for surface treatment are immersed in an aqueous solution which includes a sealing treatment agent selected according to the colour of the zinc or zinc alloy product to seal pinholes.

Abstract: A preferred embodiment of the present invention provides a process for making nickel sulfate by converting nickel metal into nickel sulfate, which may be converted to nickel hydroxide. Nickel metal is dissolved in sulfuric acid and oxygen containing gas is introduced to produce a nickel sulfate solution having nickel sulfate and water as illustrated in the following chemical equation. Ni+H2SO4+½O2?NiSO4+H2O The nickel sulfate is filtered and sulfuric acid is continually added to maintain stoichiometry within a reactor until the nickel metal is dissolved. The sulfuric acid, oxygen containing gas and nickel metal may be heated to facilitate the desired reaction. Then, the nickel sulfate may be utilized to produce nickel hydroxide.

Abstract: The invention relates to a process for direct oxidation into sulfur and/or into sulfate of sulfur-containing compounds that are contained in an amount that is less than 10% by volume in a gas, in which said gas is brought into contact with an oxidation catalyst that comprises a substrate and an active phase that comprises iron in a proportion of between 2 and 5% by weight of the oxidation catalyst at a temperature of less than 200° C. and in the presence of oxygen.

Abstract: Rhodium solutions, methods for plating structures using such rhodium solutions, and rhodium plated structures are described. The rhodium solutions can contain an increased concentration of rhodium in the form of a monomer sulfate salt. The rhodium solutions can be formed under conditions of controlled pH and controlled temperatures that increase the uniformity of the chemical composition from one rhodium solution to another. As a result, the shelf life of the rhodium solutions and plating baths using these rhodium solutions can be increased. Rhodium platings formed from these solutions can contain a low degree of dendrites, or even no dendrites. The rhodium platings can also exhibit less internal stress and can be less susceptible to cracking.

Abstract: The present invention relates to a method for preparing an electroactive metal polyanion or a mixed metal polyanion comprising forming a slurry comprising a polymeric material, a solvent, a polyanion source or alkali metal polyanion source and at least one metal ion source; heating said slurry at a temperature and for a time sufficient to remove the solvent and form an essentially dried mixture; and heating said mixture at a temperature and for a time sufficient to produce an electroactive metal polyanion or electroactive mixed metal polyanion.

Abstract: This invention relates to a method for the removal of iron as hematite from a zinc sulphate solution in atmospheric conditions during the electrolytic preparation of zinc. According to the method, the pH of the iron-containing solution is adjusted to a value of at least 2.7, oxygen-containing gas is fed into the solution and part of the hematite thus formed is recirculated to the precipitation stage.

Abstract: The invention relates to synthesis of nanoparticles, in particular to methods for producing nanoparticles with networks consisting of Z sulphate (Z=magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba) or the binary mixtures thereof). The inventive method consists in synthesising the nanoparticles by crystal growth from an ion Z source and a sulphate ion source in a liquid phase mixture. The invention produces Z sulphate nanoparticles having a small diameter and uniformly dispersible in water or other solvents in a simple way. Co-ordinating solvents like glycerine, glycol ethylene and other polyethylene glycols, polyalcohols or dimethylsulphoxide (DMSO) are used for the synthesis mixture.

Abstract: Method of synthesis for a material made of particles having a core and a coating and/or being connected to each other by carbon cross-linking, the core of these particles containing at least one compound of formula LixM1?yM?y(XO4)n, in which x,y and n are numbers such as 0?x?2, 0?y?0.6 and 1?n?1.5, M is a transition metal, M? is an element with fixed valency, and the synthesis is carried out by reaction and bringing into equilibrium the mixture of precursors, with a reducing gaseous atmosphere, in such a way as to bring the transition metal or metals to the desired valency level, the synthesis being carried out in the presence of a source of carbon called carbon conductor, which is subjected to pyrolysis. The materials obtained have excellent electrical conductivity as well as very improved chemical activity.

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 method is described for the manufacture of hydrotalcites by using at least one compound of a bivalent metal (Component A) and at least one compound of a trivalent metal (Component B), wherein at least one of these components is not used in the form of a solution, characterized in that a) at least one of the Components A and/or B which is not used in the form of a solution, shortly before or during mixing of the components, and/or b) the mixture containing the Components A and B is subjected to intensive grinding until an average particle size (D50) in the range of approx. 0.1 to 5 ?m is obtained, and optionally, after aging treatment or hydrothermal treatment, the resulting hydrotalcite product is separated, dried, and optionally calcinated.

Abstract: Provided is a process for isolating zirconium peroxosulfate and its use, either as is or to prepare high purity zirconium compounds including powders of zirconium dioxide and stabilized zirconia. The process is based on precipitating a peroxide compound from an acidic peroxide solution of zirconium and provides a simple, economical method for producing the zirconium peroxosulfate powder and its derivatives with degree of zirconium recovery more than 99%. This process further provides an effective method for the separation and purification of zirconium from a variety of elements and/or naturally occurring ores.

Abstract: A process for producing a vanadyl sulphate solution (VOSO4) comprises forming a suspension of vanadium trioxide (V2O3) in a sulphuric acid solution and contacting the V2O3 suspension with a strong oxidising agent under controlled conditions to produce the VOSO4 solution. A preferred oxidising agent is hydrogen peroxide, which is added very slowly to the V2O3 suspension due to the violent nature of the reaction.

Abstract: This invention relates to a process of treating a zirconium containing product such as zircon. The process comprises providing an alkali fusion decomposed zircon product (AFDZ) formed from reading zircon with a source of alkali metal at elevated temperatures, and treating the AFDZ to form a solid containing hydrated zirconium oxide and/or hydrated zirconium basic carbonate (hereinafter referred to as the hydrated zirconium product). The process further comprises treating the solid hydrated zirconium product to obtain in situ formation of basic zirconium sulphate as a solid thereon. The invention also relates to such a process for producing zircon derived material suitable for pigments and to such a process to produce opacifier material. The invention also relates to products of such processes.

Abstract: A method of treating aqueous salt solutions to provide a solution suitable for vitrification to a stable glass matrix for long term storage is described. In particular, salt solutions composed of aqueous nuclear waste materials are suitable for treatment by the described method. Specifically, salt solutions which have a sulfate to sodium mole ratio that does not permit easy vitrification into stable glasses may be treated by the present invention. The present method decreases the volume of vitrified glass.

Abstract: A method of extracting a halide and sulphate from an aqueous sulphate solution, such as a zinc sulphate solution, comprises subjecting the solution to solvent extraction to extract halide and sulphate from the solution and controlling the amount of sulphate extracted by selective adjustment of the acidity of the aqueous solution.

Abstract: A modified vanadium compound characterized in that vanadium sulfate (III), or a mixed vanadium compound of vanadium sulfate (III) and vanadyl sulfate (IV) contains excessive sulfuric acid other than sulfate group composing the vanadium sulfate (III) or the vanadyl sulfate (IV), and when the modified vanadium compound is used, a redox flow battery electrolyte can be prepared easily.

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: The invention provides a hydrometallurgical process for treating metal-containing sulfide ores and concentrates, comprising reacting said metal-containing sulfide with concentrated sulfuric acid at a temperature of between about 300° C. and 400° C. in the presence of oxygen to produce a solid metal sulfate product and a gaseous product which is primarily SO3, wherein said metal is selected from the group consisting of iron, copper, zinc, nickel, cobalt and manganese. Said metal sulfate product is then leached with dilute sulfuric acid to form a metal-containing solution, from which the metal values are separated by precipitation at raised H2SO4 concentrations obtained by saturating the solution with the gaseous SO3 from the sulfatization reaction step.

Abstract: A method of extracting a halide and sulphate from an aqueous sulphate solution, such as a zinc sulphate solution, comprises subjecting the solution to solvent extraction to extract halide and sulphate from the solution and controlling the amount of sulphate extracted by selective adjustment of the acidity of the aqueous solution.

Abstract: A method of treating aqueous salt solutions to provide a solution suitable for vitrification to a stable glass matrix for long term storage is described. In particular, salt solutions composed of aqueous nuclear waste materials are suitable for treatment by the described method. Specifically, salt solutions which have a sulfate to sodium mole ratio that does not permit easy vitrification into stable glasses may be treated by the present invention. The present method decreases the volume of vitrified glass.

Abstract: A process for preparing a reconstituted vanadyl sulphate/vanadous sulphate solution for use as an electrolyte in a vanadium redox battery is disclosed. The process includes preparing a starting material including a vanadyl sulphate/vanadous sulphate solution, evaporating the starting material by applying heat to form vanadyl sulphate/vanadous sulphate crystals, and re-dissolving the vanadyl sulphate/vanadous sulphate crystals with a volume of de-ionized water to form a reconstituted vanadyl sulphate/vanadous sulphate solution having substantially the same chemical composition at the starting material. A process for preparing a vanadyl sulphate/vanadous sulphate starting material from a vanadium bearing ore material, particularly a titaniferous magnetite ore material is also disclosed.

Abstract: A process for producing a solid acid catalyst, which comprises: adding a pseudoboehmite as a binder to a sulfated zirconium hydroxide, followed by kneading with an aqueous solution containing at least one metal of the Group VIII, or loading at least one metal of the Group VIII on a sulfated zirconium hydroxide, and then adding a pseudoboehmite as a binder thereto, followed by kneading with water, further followed by molding and calcining at a temperature of from 550 to 800° C.; a solid acid catalyst produced by the production process; and a method for hydrodesulfurizing and isomerizing a light hydrocarbon oil using the catalyst.

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: A process for the production of a vanadium compound from carbonaceous residues containing vanadium, which includes the steps of: (a) combusting the carbonaceous residues at a temperature of 500-690° C. in an oxygen-containing gas to form vanadium-containing combustion residues; (b) heating the vanadium-containing combustion residues at a temperature T in ° C. under an oxygen partial pressure of at most T in kPa wherein T and P meet with the following conditions: log10(P)=−3.45×10−3×T+2.21 500≦T≦1300 to obtain a solid product containing less than 5% by weight of carbon and vanadium at least 80% of which is tetravalent vanadium oxide; (c) selectively leach tetravalent vanadium ion with sulfuring acid at pH in the range of 1.5-4; (d) separating a liquid phase from the leached mixture; (e) adding an alkaline substance to the liquid phase to adjust the pH thereof in the range of 4.5-7.

Abstract: A method for treating compounds which contain reactive sulfur is disclosed, wherein the treatment produces compounds which contain sulfur in a non reactive form. The method is based on the use of an oxidizing compound selected from the group consisting of water soluble inorganic persulfates, water soluble inorganic and organic adducts of hydrogen peroxide and mixtures thereof. The method is particularly useful in preventing stress corrosion cracking of stainless steel and in preventing auto-ignition of pyrophoric iron sulfide.

Abstract: The present invention provides method of producing a trivalent and tetravalent mixed vanadium compound having excellent solubility with sulfuric acid directly from a tetravalent or pentavalent vanadium compound by using a reducing agent,and a method of producing a vanadium electrolyte. For example, a vanadium compound mainly containing a pentavalent vanadium compound; sulfur and concentrated sulfuric acid in molar ratios with respect to (one mol of vanadium atom in the pentavalent vanadium compound) 0.35 to 0.4:1.2 to 1.9 are kneaded into paste form, and the paste-form mixture is calcined at a temperature of not less than 150° C. to less than 440° C. so that a trivalent and tetravalent mixed vanadium compound is obtained, and a redox flow battery-use vanadium electrolyte is obtained by dissolving the trivalent and tetravalent mixed vanadium compound in a sulfuric acid solution.

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: A method for treating compounds which contain reactive sulfur is disclosed, wherein the treatment produces compounds which contain sulfur in a non reactive form. The method is based on the use of an oxidizing compound selected from the group consisting of water soluble inorganic persulfates, water soluble inorganic and organic adducts of hydrogen peroxide and mixtures thereof. The method is particularly useful in preventing stress corrosion cracking of stainless steel and in preventing auto-ignition of pyrophoric iron sulfide.

Abstract: A method for treating compounds which contain reactive sulfur is disclosed, wherein the treatment produces compounds which contain sulfur in a non reactive form. The method is based on the use of an oxidizing compound selected from the group consisting of water soluble inorganic persulfates, water soluble inorganic and organic adducts of hydrogen peroxide and mixtures thereof. The method is particularly useful in preventing stress corrosion cracking of stainless steel and in preventing auto-ignition of pyrophoric iron sulfide.

Abstract: The present invention pertains to a composite powder comprising (A) an alkali metal silicate particle having an average particle size of from 1 to 500 &mgr;m; and (B) a water-soluble salt particle having an average particle size of from 0.01 to 50 &mgr;m, of which solubility to water at 20° C. is 1 g/100 g or more, wherein the alkali metal silicate particle has a composition formula in an anhydride form represented by: xM2O.ySiO2.zMeO (I) wherein M stands for Na and/or K; Me stands for Ca and/or Mg; y/x is from 0.5 to 4.0; z/x is from 0 to 1.0; and Mg/Ca in MeO is from 0 to 10, and wherein the composite powder has a (A)/(B) weight ratio of from 1/9 to 99/1; and a detergent composition comprising the composite powder. The composite powder is a composite powder having a remarkably enhanced storage stability of the alkali metal silicate without impairing the ion exchange capacity owned by the alkali metal silicate.

Abstract: The invention concerns a steel plate coated with a metal layer based on zinc and a zinc hydroxysulphate layer, whereof the surface density of sulphur is more than 0.5 mg/m2. The invention also concerns a method for obtaining said plate by treating a zinc coated sheet metal: either in a highly alkaline sulphate solution under polarization; or in a sulphate solution containing Zn2+ ions without polarization. The hydroxysulphate deposit brings about a pre-lubricating effect applicable to operations for forming sheet metal.

Abstract: A process for the recovery of sulphur trioxide, solutions of sulphuric acid, or organic derivatives thereof, using organic compounds and/or supercritical fluids, and catalyst. The process comprises the steps of passing a mixture of SO2 and an oxygen-containing gas over an activated carbon catalyst at a temperature of at least 15° C. and preferably at a pressure of 1-200 atmospheres, and stripping the activated carbon with either (i) a liquid organic compound selected from the group consisting of ketones, ethers, decalin, tetrahydrofurans, sulpholanes, glymes and formamides and which is non-reactive with sulphur trioxide or sulphuric acid, or (ii) a liquid organic compound capable of forming organic sulphates or sulphonates by reaction with sulphur trioxide or sulphuric acid. The process may be used to obtain sulphuric acid, or organic sulphates or sulphonates.

Abstract: A process for the crystallization and re-establishment of a vanadyl/vanadous sulphate solution to its original chemical composition, and the use of a vanadium bearing ore material, in particular a titaniferous magnetite ore material, for producing the vanadyl/vanadous sulphate solution or crystals, particularly for use as an electrolyte in a vanadium redox battery.

Abstract: A method of treating an acid treatment solution which includes steps of adding sulfuric acid to an acid treatment solution which contains therein non-alkaline metal ions to produce sulfate, and recovering the regenerated acid treatment solution from the acid treatment solution to which the sulfuric acid has been added by separating the sulfate therefrom. Also, a device for realizing the method, and a method of fabricating a support for a planographic printing plate using the same.

Abstract: A modified vanadium compound of the present invention in such that vanadium sulfate (III) or a mixed vanadium compound of vanadium sulfate (III) and vanadyl sulfate (IV) contains excessive sulfuric acid other than sulfate group composing the vanadium sulfate (III) or the vanadyl sulfate (IV), and when the modified vanadium compound is used, a redox flow battery electrolyte can be prepared easily.

Abstract: The present invention relates to a process of oxidation, of the wet oxidation or ozonization type, of a liquid contained in a reactor. The gas of the gas headspace is aspirated into the liquid, and the portion which is not dissolved in the liquid is recovered in the gas headspace. The agitation means creates a flow of liquid immediately adjacent to the end of the duct opening into the liquid, and generates a gas/liquid dispersion in the zone, within which the liquid reacts with the gas, then conveys and ejects the said dispersion at its periphery, such that the gas is dissolved in the liquid in the zone extending from the agitation means to the surface of the liquid. The said process is particularly suitable for oxidations which make use of considerable quantities of oxygen or of ozone. It is particularly applied for the oxidation of papermaking liquors.

Abstract: The present invention provides method of producing a trivalent and tetravalent mixed vanadium compound having excellent solubility with sulfuric acid directly from a tetravalent or pentavalent vanadium compound by using a reducing agent,and a method of producing a vanadium electrolyte. For example, a vanadium compound mainly containing a pentavalent vanadium compound; sulfur and concentrated sulfuric acid in molar ratios with respect to (one mol of vanadium atom in the pentavalent vanadium compound) 0.35 to 0.4:1.2 to 1.9 are kneaded into paste form, and the paste-form mixture is calcined at a temperature of not less than 150° C. to less than 440° C. so that a trivalent and tetravalent mixed vanadium compound is obtained, and a redox flow battery-use vanadium electrolyte is obtained by dissolving the trivalent and tetravalent mixed vanadium compound in a sulfuric acid solution.

Abstract: A process for providing a zirconium basic sulfate includes providing a zirconium oxychloride solution, and then dialyzing the solution against a liquid selected from water and an aqueous solution across at least one anion exchange membrane to provide a dialyzate and diffusate. The dialyzate includes at least 90 percent of the zirconium ions of the zirconium oxychloride chloride solution and has a total acidity that is lower than the original zirconium oxychloride solution. A precipitate including zirconium basic sulfate may be formed from at least a portion of the diffusate. The zirconium oxychloride solution may be provided, for example, by dissolving zirconium tetrachloride in one of water and a hydrochloric acid solution. A material including zirconium basic sulfate produced by the process of the invention also is disclosed.

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: A process is provided for producing potassium sulfate by reacting ammonium sulfate and potassium chloride at a temperature of about 30 to 40° C. to produce a slurry containing K2SO4·NH4·2SO4 double salt, and reacting this double salt with an aqueous solution containing potassium chloride at a temperature of about 30° C. to produce a slurry containing potassium sulfate. The slurry containing potassium sulfate is subjected to a solids/liquid separation step to obtain potassium sulfate crystals having a size in the range of about 20 mesh to about 150 mesh.

Abstract: The invention relates to a method for the treatment of fluoboric electrolyte resulting from the processes of electro-extraction of metals such as copper and lead comprising a leaching stage with fluoboric acid, in order to recycle said fluoboric acid to be recirculated to said leaching stage devoid of impurities of metals such as Me=Fe, Zn, Ca, Mg, Cd, characterized in that it comprises the stages of: a) treating said fluoboric electrolyte comprising Cu(BF4)2 or Pb(BF4)2 with H2S in order to precipitate CuS or PbS respectively in accordance with the reactions Cu(BF4)2+H2S=>CuS+2HBF4  (1) Pb(BF4)2+H2S=>PbS+2HBF4  (2) thus obtaining a solution of HBF4 containing the fluoborates of said metals Me, said solution being separated, b) treating said Me fluoborates with H2SO4 in accordance with the reaction 2 Me(BF4)n+n H2SO4=>Me(SO4)n+2n HBF4  (3) (where Me=Fe, Zn, Ca, Mg, Cd) it being possible for said sulp

Abstract: A process for the removal of thiosulphate from spent Stretford solution, The process comprises adjusting the spent Stretford solution to an acidic pH, preferably in the range of 1 to 3, and adding a peroxygen compound. The process allows the user to recycle spent Stretford solution in a cost effective manner by taking advantage of previously unknown buffering properties in the solution.

Abstract: A method of purifying a crude nickel sulfate solution to give pure nickel sulfate through solvent extraction, in which the impurities such as cobalt, calcium, magnesium, iron, zinc, copper, sodium, ammonia and others to be in the crude solution are removed while, if necessary, effectively recovering cobalt, and for which the amount of a neutralizer to be used is reduced and the cost of treating wastewater is also reduced includes an extraction step of adding an organic acid extractant to a crude nickel sulfate solution to thereby extract nickel into the extractant to give a nickel-loaded organic phase, followed by a scrubbing step of scrubbing the organic phase as obtained in the previous extraction step with a nickel-containing scrub solution to thereby remove sodium and ammonia from the organic phase; and a second purifying step of adding a crude nickel sulfate solution to the nickel-retaining organic phase as obtained in the previous first purifying step so as to exchange the nickel in the organic phase wi

Abstract: The specification discloses an apparatus and method for treating a slurry containing sodium sesquisulfate to recover sulfate and acid constituents therefrom. The apparatus includes a treatment vessel having a separation wall delineating a clarifying zone and a mixing zone. Slurry containing sesquisulfate crystals is introduced into the mixing zone along with water and the material is mixed to promote dissolution of the crystals and formation of sodium sulfate solids. Sodium sulfate solids are collected in a lower portion of the treatment vessel and conveyed out of the vessel, and liquid from the clarifying zone is conducted from an upper end of the treatment vessel to a conventional liquid processing unit. Treatment of a sesquisulfate-containing slurry in accordance with the invention provides sodium sulfate containing little or no sesquisulfate crystals thereby reducing the need for vacuum filtration or other expensive separation techniques to recover sulfuric acid and sodium sulfate solids from the slurry.

Abstract: The present invention is directed towards a system that makes high quality gypsum from a dry flue gas desulfurization process which utilizes a low temperature regeneration of the carbon adsorbent in the flue gas process. The high quality gypsum is easily filterable with large crystal size and has high purity with few contaminants, such as calcium sulfite and heavy metals. This invention is also directed towards a system that regenerates the carbon used in dry flue gas desulfurization at a temperature below 120.degree. C. and the recycling of sodium hydroxide to form a sodium sulfite reducing solution for carbon adsorbent regeneration.