Abstract: Systems and methods of producing potassium sulfate can involve converting a mixed salts feed stream into a conversion end slurry in a conversion unit, the mixed salts feed comprising at least one potassium-containing salt, at least one chloride-containing salt, at least one magnesium-containing salt and at least one sulfate-containing salt and the conversion end slurry comprising schoenite; separating conversion end slurry into a conversion end solids stream and a conversion brine; leaching the conversion end solids stream in a crystallization unit to produce a potassium sulfate product stream comprising potassium sulfate and a crystallizer mother liquor comprising magnesium sulfate and potassium sulfate; collecting heat generated in the conversion unit by a heat pump; and providing at least a portion of the heat collected to the crystallization unit to regulate a temperature of the potassium sulfate product stream and the crystallizer mother liquor stream contained in the crystallization unit.

Abstract: The present invention relates to a process for producing sodium sulphate from phosphogypsum, comprising: a step (101) of lixiviation of phosphogypsum by means of a basic solution so as to obtain a sodium sulphate solution (S) containing metal impurities, said basic solution comprising a chelating agent suitable for forming complexes with at least one part of said metal impurities, at least one first step (103, 104) of filtration of the sodium sulphate solution by a nanofiltration membrane (NF1, NF2), so as to form a concentrate (C1, C2) containing said complexes and a permeate (P1, P2), a step (105) of evaporation of the permeate (P1, P2) so as to form anhydrous sodium sulphate.

Abstract: Methods of processing an aqueous solution comprising potassium sulfate and magnesium sulfate include crystallizing K2SO4, crystallizing recycle crystals, and mixing at least a portion of the recycle crystals with the aqueous solution. Systems for processing potassium sulfate and magnesium sulfate include a first crystallizer and a second crystallizer in fluid communication with the second mix tank. The second crystallizer is structured and adapted to precipitate recycle crystals from the concentrated liquor to form a potassium-depleted recycle brine. The recycle crystals precipitated in the second crystallizer have a composition suitable to be recycled to the first crystallizer to increase the production of SOP.

Abstract: Processes are for the conversion of the sulfur compounds to elemental sulfur through different catalytic stages after the reaction furnace of the Claus unit with air or oxygen. The steps are: 1—Conventional Claus thermal or catalytic stage; 2—Oxygen Scavenger catalytic stage to capture excess oxygen from the reaction furnace and to perform Claus reaction; a Selective Reduction stage that converts SO2 to elemental sulfur; and 4—Selective Oxidation stage that converts H2S to elemental sulfur. The tail gas flows to the incineration and stack and to the incineration plus caustic scrubber for achieving zero emissions.

Abstract: The invention relates to a potassium sulphate powder wherein about 80 wt % or more of the powder has a particle size of about 0.2 mm or lower, preferably about 0.13 mm or less. The particle size preferably is such, that about 80 wt % or more is about 0.02 mm or higher, more preferably about 0.04 mm or higher. This potassium sulphate powder dissolves easily in water, more in particular, 50 gram of said potassium sulphate powder dissolves in 1 liter of water without stirring within 1 minute, preferably within 30 sec. This potassium sulphate powder is very suitable as foliar fertilizer, in particular for broad acre crops. Further, the invention relates to the use of foliar potassium fertilizer, to enhance the uptake of potassium from the soil.

Abstract: The invention relates to a CO2 y SO2 capture method comprising the following steps consisting in: a) introducing an aqueous stream of a hydroxide of an alkali or alkaline-earth metal and another gas stream of CO2 into a bubble column purifier/reactor, in order to form a carbonate of the alkali or alkaline-earth metal; b) introducing the carbonate of the alkali or alkaline-earth metal into a bubble column purifier/reactor, into which a stream of a gas mixture of CO2 and SO2 is introduced in order to form sulphite of an alkali or alkaline-earth metal and carbon dioxide; c) transforming the sulphite from step (b) into sulphate of said metal by means of oxidation with air; and d) re-circulating the unreacted CO2 produced during step (b) by reacting the slurry with the SO2, in the reactor from step (a).

Abstract: A main object of the present invention is to provide an anode active material capable of increasing energy density at the same time increasing battery safety, and a metal ion battery prepared with the anode active material. The present invention is an anode active material including an element that belongs to alunite group capable to insert and remove an ion(s) of at least one metal element selected from the group consisting of alkali metal elements and alkaline-earth metal elements, and a metal ion battery having a cathode, an anode, and an electrolyte filled between the cathode and the anode, the electrolyte conducting a metal ion(s), wherein the anode active material is contained in the anode.

Abstract: Methods of processing an aqueous solution comprising potassium sulfate and magnesium sulfate include crystallizing K2SO4, crystallizing recycle crystals, and mixing at least a portion of the recycle crystals with the aqueous solution. Systems for processing potassium sulfate and magnesium sulfate include a first crystallizer and a second crystallizer in fluid communication with the second mix tank. The second crystallizer is structured and adapted to precipitate recycle crystals from the concentrated liquor to form a potassium-depleted recycle brine. The recycle crystals precipitated in the second crystallizer have a composition suitable to be recycled to the first crystallizer to increase the production of SOP.

Abstract: Kainite mixed salt is treated with water to obtain solid schoenite and a schoenite end liquor. The latter is desulphated using recycled CaCl2 and thereafter evaporated to obtain camallite crystals, from which KCl is recovered, and a liquor rich in MgCl2. Gypsum produced during desulphatation is reacted with aqueous ammonia and CO2 to produce ammonium sulphate and calcium carbonate. The calcium carbonate is calcined to obtained CaO and CO2. The CaO is slaked and reacted with the MgCl2-rich liquor generated above to produce slurry of Mg(OH)2 in aqueous CaCl2. To this surface modifying agent is added while hot and, after cooling, the slurry yields surface modified Mg(OH)2. The filtrate rich in CaCl2 is recycled for desulphatation process above. The solid surface modified Mg(OH)2 may he calcined to produced MgO. The schoenite and KCl are reacted to produce solid sulphate of potash.

Abstract: A method for preparing an oil extractor is provided. The method includes dissolving 0.1˜30% by weight of a potassium sulfate, 0.1˜30% by weight of a potassium persulfate, and 0.1˜30% by weight of a manganese sulfate in a solvent to form a solution; heating the solution to synthesize a compound by a microwave; cooling a temperature of the compound to a room temperature; and removing the solvent from the compound. An extractor prepared from the method is also provided.

Abstract: Methods of processing an aqueous solution comprising potassium sulfate and magnesium sulfate include crystallizing K2SO4, crystallizing recycle crystals, and mixing at least a portion of the recycle crystals with the aqueous solution. Systems for processing potassium sulfate and magnesium sulfate include a first crystallizer and a second crystallizer in fluid communication with the second mix tank. The second crystallizer is structured and adapted to precipitate recycle crystals from the concentrated liquor to form a potassium-depleted recycle brine. The recycle crystals precipitated in the second crystallizer have a composition suitable to be recycled to the first crystallizer to increase the production of SOP.

Abstract: This invention refers to a novel process to obtain magnesium hydroxide and sodium sulfate from a solid raw material, which contains sodium and magnesium soluble salts, preferably in the form of sulfates, coming from a natural source or as a byproduct of an industrial process. The process consisting in the conditioning of the raw material to guarantee the correct concentrations of sodium and magnesium sulfates that is subjected to a salting-out crystallization when mixed with sodium sulfate obtaining sodium sulfate; the resulting solution is subjected to an alkali treatment to precipitate the magnesium hydroxide and the mother liquor is fed to a regeneration stage of the alkali used in the precipitation of the magnesium hydroxide as well in the sodium sulfate solution for the crystallization. The crystallization can be performed as a multistage process countercurrent to increase the purity of sodium sulfate.

Abstract: Methods of forming potassium sulfate include calcining polyhalite ore particles to convert the polyhalite ore particles to a water-soluble composition. At least a portion of the water-soluble composition is dissolved in an aqueous medium to form an aqueous solution comprising K+, Mg2+, and SO42? ions and a calcium-containing solid. The calcium-containing solid is separated from the aqueous solution to form a filtrate comprising K+, Mg2+, and SO42? ions. A potassium-containing salt is dissolved in the filtrate to increase the concentration of K+ and SO42? ions to from a concentrated liquor, and K2SO4 is crystallized from the concentrated liquor. A system for processing polyhalite ore includes a countercurrent leaching apparatus, a first mix tank, an evaporator, and at least one crystallizer.

Abstract: There is provided a low sodium sea salt and a method for producing the same. A first amount of natural seawater containing sodium, chloride, potassium, magnesium, sulfate and other trace minerals is introduced into a containment structure which is periodically exposed to the sun. Preferably, the containment structure is located outdoors in an arid climate with direct exposure to sunlight. An amount of water is evaporated forming a brine. An amount of sodium chloride is crystallized and an amount of the crystallized sodium chloride is removed so that the remaining brine includes substantial amounts of potassium, magnesium and sulfate. A second amount of natural seawater is combined with the remaining brine forming a diluted brine. An amount of water is evaporated from the diluted brine. Sodium chloride, potassium sulfate and magnesium sulfate is crystallized forming a low sodium sea salt whereby the sodium chloride is no more than 70 weight percent.

Abstract: Salts of mineral nutrients stabilized with amino acids and/or ammonium salt, product and food supplement in which they are included and procedures of obtention, where the salts are obtained with anions of organic acids or inorganic anions and metallic cations associated with amino acids and/or ammonium salt, in which the invention introduces its general structure: {[Ac]n?·Men+?n[Amino acid and/or ammonium salt]}·xH2O Where ? represents a covalent dative bond, These new compounds have better taste and more solubility in water, making them more bioavailable.

Abstract: Methods, systems, and apparatus for managing sulfur are disclosed. In some embodiments, the method comprise the following: obtaining material containing sulfur; refining the material to develop a high sulfur content heavy fraction fuel oil and a low sulfur content light fraction fuel oil; burning the low sulfur content light fraction fuel oil in apparatus that emit to the atmosphere; burning the high sulfur content heavy fraction fuel oil to produce energy thereby generating flue gas containing sulfur oxide; and removing and disposing of sulfur in the flue gas using a sulfur sequestration system that includes utilizing sulfur removed from the flue gas to form a brine material.

Abstract: The process concerns hydrometallurgical processing of manganese sulphate and manganese dithionate containing liquors and recovery of water therefrom. Sodium sulphate and/or sodium dithionate containing liquors are derived from manganese sulphate and manganese dithionate containing liquids, which are then cooled to produce crystals of sodium sulphate decahydrate and sodium dithionate dehydrate. The sodium sulphate decahydrate and sodium dithionate dehydrate crystals are then heated to a temperature sufficient to decompose the sodium sulphate decahydrate crystals to form anhydrous sodium sulphate crystals, sodium dithionate hydrate crystals and water, after which water is removed from the sodium sulphate and sodium dithionate hydrate crystal. The sodium sulphate and sodium dithionate dehydrate crystals are then heated to form anhydrous sodium sulphate, sulfur dioxide and water or steam. The anhydrous sodium sulphate is then separated from the sulfur dioxide and water.

Abstract: A cyclic process for the preparation of barium sulphate and lithium-iron phosphate comprising (i) preparing an aqueous solution containing lithium and sulphate ions and (ii) adding solid barium hydroxide at a temperature of more than 50° C., wherein the barium hydroxide is added over a period of less than 15 minutes. Also, barium sulphate obtainable by the process according to the invention.

Abstract: The invention provides a novel polyanion-based electrode active material for use in a secondary or rechargeable electrochemical cell, wherein the electrode active material is represented by the general formula AaMb(SO4)2Zd.

Abstract: A method and a system for the production of potassium sulfate. The method comprises reacting a source of water soluble potassium with a magnesium sulfate-containing substance in presence of an aqueous alcoholic solution.

Abstract: A method for of reducing the acidity and lowering the acid dewpoint of flue gas, the method steps including partially combusting the fuel in a first stage to create a reducing environment; maintaining the reducing environment for a sufficient time period such that reducible acids are reduced to achieve a desirable acidity concentration in the flue gas; and combusting the remainder of the fuel and combustion intermediates in a second stage with oxidizing environment; thereby decreasing the acidity and lowering the acid dewpoint of the flue gas by reducing the acid concentration of the gas.

Abstract: The present invention relates to a process for the recovery of sulphate of potash (SOP) from bittern. Kainite is obtained by fractional crystallization of the bittern. Kainite is converted into schoenite with simultaneous removal of NaCl and the filtrate (SEL) is used for production of KCl. Schoenite is reacted with aqueous KCl to yield SOP and the filtrate (KEL) is recycled in the kainite to schoenite conversion step. The production of KCl from SEL is carried out with the aid of dipicrylamine (DPA). Lime is treated with DPA in water for the production of highly soluble Ca (DPA)2, which in turn treated with SEL to produce insoluble K(DPA). K(DPA) is treated with HCl to produce KCl and insoluble DPA, which can be recycled for the production of Ca (DPA)2. The aqueous KCl thus obtained is treated with schoenite to prepare SOP. The KEL obtained along with SOP is recycled to generate schoenite.

Abstract: The present invention relates to a catalyst for reducing mercury, which comprises a reagent comprising any of the sulfites of potassium, sodium, calcium and magnesium, or any of the phosphates thereof, or a combination of them, as a main reagent of a catalyst component. And the present invention relates to the catalyst for reducing mercury, wherein the catalyst component is mixed with a different salt as an agent for inhibiting crystallization of the catalyst component.

Abstract: Embodiments of the invention provide a system and process for recovering useful compounds from a byproduct composition produced in a silicon tetrafluoride production process.

Abstract: A method is disclosed for production of a sulfate-containing chlorine free salt and anhydrous gaseous HCl from a metal chloride (MClx), oleum and water. MClx and oleum are mixed together with a water-containing liquid, forming gaseous HCl and a solution of a sulfate-containing salt. The salt is precipitated from the solution, and in a preferred embodiment, the supernatant liquid from the precipitation is recycled to the reaction mixture as the water-containing liquid in subsequent reaction cycles. The exothermicity of the reaction between the water-containing liquid and the oleum is sufficient to remove chlorine in the form of substantially pure useful HCl and enables the process to proceed without additional heating of the reaction mixture. When the metal is potassium, this method produces high-purity novel sulfate salts with high potassium content K3(NH4)(SO4)2, 3K2SO4.MgSO4 and 3K2SO4.CanMg1-nSO4.

Abstract: A process for producing potassium magnesium sulfate, comprising reacting sulfuric acid with potassium chloride and magnesium chloride at a temperature in a range comprised between about 100 and about 160° C., thereby producing potassium magnesium sulfate and hydrochloric acid, the sulfuric acid being reacted with potassium chloride and magnesium chloride simultaneously or sequentially.

Abstract: A metal sulfate alcohol composition as well as a process to produce such composition is disclosed. Also disclosed is a process to produce polyester containing the metal sulfate alcohol composition.

Abstract: A method can, in one general aspect, include steps for the recovery of potassium sulfate and mirabilite from glaserite. In another general aspect, a method includes dissolving glaserite in water at an elevated temperature to produce a saturated or nearly saturated solution, and cooling the solution to a temperature where potassium sulfate and mirabilite will crystallize from the solution as stable phases. In yet another general aspect, a method includes adding glaserite to a saturated solution of glaserite in water and mixing for enough time at a temperature where the glaserite will decompose into potassium sulfate and mirabilite as stable phases. In yet another general aspect, a method includes separating potassium sulfate from mirabilite using a froth floatation process.

Abstract: The invention is directed to a process for the manufacture of optionally doped nanoparticulate metal sulfate wherein the metal is selected from polyvalent metals or monovalent transition metals, said process comprising the step of heating a reaction mixture comprising a) a polar organic solvent comprising at least two hydroxy groups or a polar organic solvent comprising at least one sulfoxide group, b) a source of a polyvalent metal or monovalent transition metal, a sulfate source, and optionally a dopant metal source, and c) a base selected from i) bases having an aromatic N-containing heterocycle with the exception of imidazole, ii) bases having an aliphatic N-containing heterocycle, iii) aliphatic hydroxy-substituted amines, iv) aliphatic polyamines, v) aromatic amines, vi) ammonia and ammonia-releasing compounds, and vii) metal hydroxides. The invention is also directed to the resulting metal sulfate nanoparticles.

Abstract: A method can, in one general aspect, include steps for the recovery of potassium sulfate and mirabilite from glaserite. In another general aspect, a method includes dissolving glaserite in water at an elevated temperature to produce a saturated or nearly saturated solution, and cooling the solution to a temperature where potassium sulfate and mirabilite will crystallize from the solution as stable phases. In yet another general aspect, a method includes adding glaserite to a saturated solution of glaserite in water and mixing for enough time at a temperature where the glaserite will decompose into potassium sulfate and mirabilite as stable phases. In yet another general aspect, a method includes separating potassium sulfate from mirabilite using a froth floatation process.

Abstract: A method for purifying heavy metal impurities (such as antimony, arsenic, iron, cadmium, and lead) from 28 to 38 weight percent aqueous crude sodium sulfate solution is achieved by adding ferric sulfate to the aqueous crude sodium sulfate solution to form a suspension, progressively neutralizing the suspension from a pH of less than 3.5 up to at least 6, and separating the ferric-sulfate-nucleated precipitate from the suspension. An oxidizing agent such as peroxide is optionally added to the suspension to augment adsorption of the heavy metals.

Abstract: Methods for scrubbing gas streams to remove acid gases including sulfur dioxide, mercury-containing substances, and/or nitrogen oxides from the gas stream. The gas stream is contacted with a potassium-based sorbent effective for removing at least a portion of the acid gases. The partially cleaned gas stream is then contacted with an oxidant effective to remove at least a portion of the nitrogen oxides and/or mercury-containing substances after partially removing the acid gas substance.

Abstract: A method is provided for reducing the fouling during the removal of sulfur trioxide from a flue gas stream by maintaining the reagent (i. e. sodium sesquicarbonate) in contact with the flue gas for a sufficient time and temperature to react a portion of the reagent with a portion of the sulfur trioxide to substantially avoid formation of liquid phase NaHSO4 reaction product that combines with the fly ash so as to not form a sticky ash residue that adheres to the flue gas duct, wherein the reaction product of the reagent and the sulfur trioxide is selected from the group consisting of Na2SO4, Na2S2O7 and mixtures thereof.

Abstract: A pretreatment agent for a sample to be subjected to Limulus assay comprising an alkali metal sulfate and/or an alkaline earth metal sulfate wherein the sulfate(s) has a final concentration of 20 mM or more when the sulfate(s) is allowed to contact with the sample, or an alkali metal halide and/or an alkaline earth metal halide wherein the halide(s) has a final concentration of from 0.4 M to 1.2 M or less when the halide(s) is allowed to contact with the sample, or a kit for Limulus assay reagent comprising thereof as a composing article.

Abstract: A composition comprising a solution of potassium monopersulfate having an active oxygen content of from about 3.4% to about 6.8% and a process for its preparation including neutralization with an alkaline material is disclosed.

Abstract: Process for the conversion of sodium bromide to anhydrous hydrobromic acid and sodium bisulfate, said process with the following sequential steps: reaction of sodium bromide and sulfuric acid in a solution of water to produce hydrobromic acid and sodium bisulfate wherein the conversion of sodium bromide is greater than about 99%; adsorption of iron bromide onto a solid adsorbent; separation of hydrobromic acid and water from the sodium bisulfate; separation and drying of hydrobromic acid; and solidification of the sodium bisulfate into a flaked or granular form.

Abstract: A process for co-producing anhydrous hydrogen bromide and a purified bisulfate salt by (a) reacting a bromide salt with sulfuric acid to produce crude hydrogen bromide and crude bisulfate salt; (b) purifying the crude hydrogen bromide to produce anhydrous hydrogen bromide; and (c) removing bromide from the crude bisulfate salt to form a purified bisulfate salt. There are also provided improvements in the bisulfate purification and bromine removal, whereby bromine is removed from the system by a distillation process and the bromide is removed from the crude bisulfate via a spray drying process.

Abstract: A batch process for co-producing anhydrous hydrogen bromide and a purified bisulfate salt comprising: (a) charging a batch reactor with a bromide salt slurry, wherein the slurry is more than 50% by weight bromide salt; (b) reacting the slurry with sulfuric acid in a batch reaction wherein bromide salt is consumed to produce crude aqueous hydrogen bromide and crude bisulfate salt, the crude bisulfate salt containing bromine; (c) prior to or concurrently with step (b) adding hydrogen bromide to the reactor; (d) purifying the crude hydrogen bromide to produce anhydrous hydrogen bromide; and (e) removing bromine from the crude bisulfate salt to form a purified bisulfate salt.

Abstract: A cathode active material for a lithium secondary cell used in a cellular phone is disclosed. The cathode active material for the lithium secondary cell and the method the same having a high capacity and a long lifetime, different from LiCoO2 and LiMn2O4, Li(Ni, Co)O2, and V-system oxide that has been researched as the active material for substituting LiCoO2 are provided. The cathode active material for the lithium secondary cell in the next formula 1 is obtained by heating or chemically treating diadochite [Fe2(PO4)(SO4)(OH).6H2O] that is the mineral containing PO43?, SO42?, and OH?. LiaFebMc(PO4)x(SO4)y(OH)z ??(1) In the formula, M is at least one element selected from a radical consisting of Mg, Ti, Cr, Mn, Co, Ni, Cu, Zn, Al, and Si, with 0?a, c?0.5, 1?b?2, 0.5?x, y, z?1.5.

Abstract: A process for producing potassium sulfate from potash and sodium sulfate, which involves providing a source of sodium sulfate and passing the sodium sulfate through cationic exchanger. Eluted potassium sulfate containing sodium sulfate is reacted with potash to form further potassium sulfate.

Abstract: Process for the conversion of sodium bromide to anhydrous hydrobromic acid and sodium bisulfate, said process with the following sequential steps: reaction of sodium bromide and sulfuric acid in a solution of water to produce hydrobromic acid and sodium bisulfate wherein the conversion rate is greater than about 95%; separation of hydrobromic acid and water from the sodium bisulfate; separation of hydrobromic acid from water; and drying of hydrobromic acid.

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: The invention refers to a method for an integrated treatment of cellulose pulp. The method includes the steps: providing said cellulose pulp (1), providing a determined quantity of white liquor (2) including alkali and sulphur components, providing an oxygen-containing gas, oxidizing (5) the sulphur components of the white liquor by the supply of a part of said gas in such a way that at least a part of the sulphur is present in the form of sulphate, transporting the cellulose pulp having a certain kappa number to at least one mixing device (4), and supplying the oxidized white liquor from the oxidizing step to the cellulose pulp, supplying a part of said gas to the cellulose pulp in said mixing device, mixing the cellulose pulp with the oxidized white liquor and said gas in said mixing device, and transporting the cellulose pulp from said mixing device to a delignification reactor (6) for oxygen delignification of said cellulose pulp, wherein the kappa number is reduced.

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 hydrochloric acid and neutralized sulfates comprising: reacting sulfuric acid with an alkaline metal chloride in order to obtain a liquor containing hydrochloric acid, an acid alkaline metal sulfate and an excess of sulfuric acid; separating the hydrochloric acid from the liquor containing the hydrochloric acid, the acid alkaline metal sulfate and the excess of sulfuric acid; neutralizing the acid alkaline metal sulfate and the excess sulfuric acid by adding to the remaining liquor after the separation of the hydrochloric acid a neutralizing agent to obtain a neutralized mass; cooling the neutralized mass to crystallize the neutralized alkaline metal sulfate and obtain neutralized alkaline metal sulfate crystals; and separating the neutralized alkaline metal sulfate crystals from the liquor.

Abstract: A method of making a cesium salt is described and involves reacting a cesium sulfate containing solution with lime to form 1) a solution containing at least cesium hydroxide and 2) a residue comprising calcium sulfate. The method further involves removing the residue from the solution and converting the cesium hydroxide that is present in the solution to at least one type of cesium salt. The present invention further relates to uses of the cesium salt as well as methods of making cesium hydroxide using lime. Also, methods of making alkali metal salts and alkali metal hydroxides are also described.

Abstract: A method for removing sodium sulfate from nickel and ammonia containing aqueous effluents. The effluents, typically from a nickel hydroxide production process, are cooled to or below 30° C. to crystallize and precipitate the sodium sulfate and dewater the effluent. The sodium sulfate is retrieved and the remaining solution is recycled back to the nickel hydroxide production process.

Abstract: The invention relates to a process of producing chlorine dioxide comprising the steps of reducing chlorate ions in an acid reaction medium maintained in a reaction zone of a chlorine dioxide generator, which reaction medium contains alkali metal ions and sulfate ions, so to form chlorine dioxide and a solid salt of acidic alkali metal sulfate. The process further comprises the steps of separating said solid acidic alkali metal sulfate from the reaction medium, contacting said solid acidic alkali metal sulfate with an aqueous medium in a mixing tank to effect at least partial conversion to neutral solid alkali metal sulfate, separating the at least partially neutralized solid alkali metal sulfate from the aqueous medium on a rotary drum filter operating with vacuum inside and with part of the drum submerged in a slurry of the at least partially neutralized solid alkali metal sulfate and the aqueous medium, and forming an acid filtrate.

Abstract: A process for producing potassium sulfate from potash and sodium sulfate, which involves providing a source of sodium sulfate and passing the sodium sulfate through cationic exchanger. Eluted potassium sulfate containing sodium sulfate is reacted with potash to form further potassium sulfate.

Abstract: The present invention provides an inexpensive process for the preparation of lithium salts of formula LiX having a desired or required level of purity using lithium chloride and lithium sulfate. In the process of the invention, a lithium salt selected from lithium chloride, lithium sulfate, and combinations thereof is reacted with NaX or KX in a aqueous, semiaqueous, or organic solution and the precipitated salts are removed to obtain the LiX solution of desired purity. Preferably, a semiaqueous solution containing water and an organic solvent is used at some point in the reaction. The process of the invention eliminates the use of highly acidic materials and thus reduces the cost of raw materials and the need for specialized equipment.