Abstract: The present relates to a method for producing calcium sulfate solid crystals and hydrochloric acid (HCl) from a calcium chloride solution comprising the steps of feeding a continuous stirred-tank reactor with a calcium chloride solution, sulfuric acid and water; mixing the calcium chloride solution, sulfuric acid and water in the reactor; and maintaining the reactor a temperature of less than about 70° C., converting the calcium chloride solution, sulfuric acid and water into HCl and calcium sulfate solid crystals. The method described herein can be incorporated as a means for regenerating HCl from CaCl2 solutions which are generated in the metallurgical industry when processing calcium-bearing ores for recovering metals like rare earth elements.

Abstract: A method for processing an amine-based solvent contaminated by the introduction of sulfur oxides is provided. A potassium compound is introduced into a contaminated solvent, and the contaminated solvent is cooled so that a solubility of a potassium sulfate becomes less than a specified concentration of potassium sulfate. Further, an oxidizing agent is introduced into the contaminated solvent so that a potassium sulfite is oxidized to potassium sulfate. The potassium sulfate is filtered out, wherein a prepared solvent is formed. Further, a device for processing an amine-based, sulfur oxide-contaminated solvent is provided.

Abstract: The invention relates to a method adapted for integration with a carbonate absorption/stripping process for removal of carbon dioxide, the method and system including the steps of: converting a source of alkali from a first industry to a non-carbonate alkali; feeding the non-carbonate alkali as makeup to a carbonate absorption system for stripping carbon dioxide from emissions from a second industry; recovering an output from the system for stripping carbon dioxide, and in the process of conversion of the alkali from the first industry, utilising energy from the second industry.

Abstract: A method and a system for the production of potassium sulfate. The method comprises reacting a chloride of potassium with a magnesium sulfate in an aqueous alcoholic solution, with recycling of magnesium sulfate and production of hydrochloric acid, where the recycling of magnesium is done by a reaction of sulfuric acid on resulting magnesium chloride with corresponding production of magnesium sulfate and hydrochloric acid.

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: 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: 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 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 process for the brightening of continuously produced sodium hydrogensulfate obtained in the reaction of sodium chloride and concentrated sulfuric acid in molten sodium hydrogensulfate in a circulation reactor, wherein evolved hydrogen chloride and heating gases generated by an immersion burner are withdrawn at various sites and seed crystals are added for a faster conversion of initially formed metastable phases, is that from 0.01 to 0.05% by weight of aluminium oxide and/or from 0.5 to 1.5% by weight of magnesium oxide and/or magnesium sulfate and, optionally, additionally calcium sulfate are added as seed crystals.

Abstract: The present invention is directed to a novel integrated process for the recovery of sulphate of potash (SOP) from sulphate rich bittern. The process requires bittern and lime as raw materials. Kainite type mixed salt is obtained by fractional crystallization of the bittern, and is converted to schoenite which is subsequently reacted with muriate of potash (MOP) for its conversion to SOP. End liquor from kainite to schoenite conversion (SEL) is desulphated and supplemented with MgCl2 using end bittern generated in the process of making carnallite. Decomposed carnallite liquor produced is reacted with hydrated lime for preparing CaCl2 solution and high purity Mg(OH)2 having low boron content. It is shown that the liquid streams containing potash are recycled in the process, and the recovery of potash in the form of SOP is quantitative.

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 specification discloses a continuous process for producing hydrogen chloride whereby sulfuric acid and an alkali metal chloride are fed to a direct fired reaction chamber in a molar ratio of approximately one to one, products comprising hydrogen chloride and the corresponding alkali metal sulfate are withdrawn, and the hydrogen chloride is separated from combustion gases. The reaction chamber provides for the counter flow of gaseous and solid streams within the reaction chamber, such that a chloride-free sulfate is obtained.

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 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 new process of preparing potassium sulfate fertilizer and other metal sulfates from the chlorides and other halides of these metals. The process utilizes the discovery that sulfur dioxide or trioxide, when introduced as a fluidizing medium into shallow beds of the halide salts at moderately elevated temperatures (1000° F.-1150° F.) in a counter current process results in the conversion of the metal halides into metal sulfates and the halide gas. The process is carried out in a series of true fluidized beds preferably but not necessarily arranged in a vertical configuration so that the solids flow downward due to the fluidized process and the sulfur dioxide or trioxide gases flow counter currently in an upward direction producing pure metal sulfates at the bottom and pure halide gas at the top.

Abstract: A process for the preparation of potassium sulfate, sodium bicarbonate and sodium carbonate. The process involves the treatment of potash brines by the reaction of sodium chloride and potassium chloride with calcium sulfate and sodium sulfate. Syngenite precipitate (CaSO4.K2SO4&khgr;H2O) is produced and a first filtrate containing sodium chloride and potassium chloride. The syngenite precipitate is reacted with ammonium bicarbonate at between 70° C. and 100° C., with the result being calcium carbonate precipitate and a second filtrate containing ammonium sulfate and potassium sulfate. The second filtrate is cooled to a temperature of between 20° C. and 50° C. and treated with potassium chloride. A potassium sulfate precipitate results. The sodium bicarbonate is precipitated from the first filtrate by the addition of ammonium bicarbonate to the first precipitate. The sodium bicarbonate may be calcined to form sodium carbonate.

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 present invention provides a process for producing potassium sulfate from a potash and a sodium sulfate source, comprising the steps of: (a) treating a portion of the potash source and sodium sulfate source, such that glaserite is crystallized out of solution and a first mother liquor is produced; (b) converting the glaserite to precipitate potassium sulfate in a second mother liquor; (c) recycling the second mother liquor to the portion of the potash source and sodium sulfate source; (d) subjecting the first mother liquor to evaporative crystallization to produce sodium chloride in a third mother liquor; and (e) recycling the third mother liquor to the portion of the potash source and sodium sulfate source.

Abstract: A process for producing potassium sulfate, sodium sulfate, and sodium chloride from potash and a sodium sulfate/water source, which includes: (a) treating the sodium sulfate/water source to produce a slurry containing anhydrous sodium sulfate; (b) concentrating the slurry to form a concentrate and a diluent; (c) treating the diluent to precipitate out anhydrous sodium sulfate; (d) subjecting the anhydrous sodium sulfate from steps (b) and/or (c) and/or from a different source to conversion with potash in an aqueous medium to yield glaserite and a first mother liquor, with any excess anhydrous sodium sulfate being taken as co-product; (e) converting the glaserite with potash and water to produce a precipitate of potassium sulfate and a second mother liquor; (f) returning the second mother liquor to step (d); (g) subjecting the first mother liquor to evaporative crystallization such that substantially pure sodium chloride is precipitated in a third mother liquor; and (h) returning the third mother liquor for co

Abstract: A process for the manufacture of potassium sulfate from a sodium sulfate source, potash and water, comprising the steps of: (a) introducing the sodium sulfate source, water and potash into a differential countercurrent contactor; and (b) causing the sodium sulfate source, potash and water to contact differentially to produce potassium sulfate.

Abstract: A process for producing potassium sulfate or potassium sulfate and sodium sulfate from potash and a sodium sulfate/water source, which includes: (a) subjecting a sodium sulfate source to conversion with potash in an aqueous medium to yield glaserite precipitate and a first mother liquor; (b) converting the glaserite precipitate with potash and water to produce a potassium sulfate precipitate and a second mother liquor; (c) returning the second mother liquor to step (a); (d) subjecting the first mother liquor to treatment, such as evaporative crystallization, such that a sodium chloride and sodium sulfate solids mixture or pure sodium chloride is precipitated in a third mother liquor; (e) subjecting the solids from step (d) to a sodium sulfate/water source to produce anhydrous sodium sulfate; and (f) returning the third mother liquor for conversion to potassium salts.

Abstract: In minimizing effluents from a cellulose pulp mill, liquid effluents from a bleach plant are concentrated, and then incinerated to produce a residue including sodium, sulfate, and sodium chloride. This residue is distilled with sulfuric acid to produce gaseous hydrogen chloride and remaining residue, the HCl being used in chloride dioxide production for the bleach plant, while the remaining residue is passed to the recovery loop (e.g. recovery boiler). Sulfur containing gases from the non-condensible gas system may be combusted to produce gaseous sulfur dioxide, which is then converted to sulfuric acid, to distill the residue. Where a non-chlorine bleach plant is provided, the liquid effluents may be concentrated in evaporators and then passed directly to the recovery boiler. The liquid streams in the mill are managed by a cascade principle to reserve the cleanest water for only those processes where it is needed while minimizing its use where it is not necessary.

Abstract: The present invention concerns a method for the purification and/or electrolysis of an aqueous potassium chloride solution, in which the sulphate ions are removed from the aqueous potassium chloride solution by precipitation as potassium sulphate and/or as a potassium sulphate-containing salt mixture and/or as a potassium sulphate-containing compound.

Abstract: A process is disclosed for the production of potassium sulfate from potassium chloride by means of a sulfate-laden anion exchanger, according to which as reaction solution, the exchanger is intensively contacted with a saturated potassium chloride solution, after saturation with potassium sulfate, and thereupon again separated, whereupon from this solution the crystals formed therein are separated, while the depleted anion exchanger is regenerated by intensive contact with a magnesium sulfate solution.

Abstract: Potassium chloride and sulfuric acid are reacted in a recycled aqueous solution in the stoichiometric ratio required for potassium sulfate production. Hydrogen chloride produced by the reaction of the potassium chloride and sulfuric acid is evaporated in admixture with water or in anhdrous form. The resulting solution is cooled to crystallize a potassium sulfate salt, preferably potassium bisulfate. The potassium sulfate salt is separated from the mother liquor and the mother liquor is recycled to the reaction step. The potassium sulfate salt is dissolved in an aqueous solution and sequentially decomposed to produce potassium sulfate and a mother liquor rich in sulfuric acid. The mother liquor rich in sulfuric acid is concentrated and recycled to the reaction step.

Abstract: An improved process for the production of potassium sulfate crystals by the reaction of saturated solution of potassium chloride with langbeinite in the solid phase at a temperature of from 45.degree.-55.degree. C., thereby forming potassium sulfate crystals and magnesium chloride solution comprising the step of conducting the reaction in the presence of a growth enhancer comprising monosulfonated or monosulfated surfactant and a neutralized disulfonated surfactant in a weight ratio of from about 0.14 to 0.69.

Abstract: Gypsum as a byproduct in the manufacture of phosphoric acid is converted into potassium sulphate or sodium sulphate by subjecting an aqueous slurry to anion exchange under acidic conditions. Adding solid potassium chloride to the obtained solution of potassium sulphate causes the latter to crystallize in pure state, the potassium chloride solution recovered after filtering off the crystallized potassium sulphate being used for the regeneration of the anion exchanger.

Abstract: This improved method comprises a first dry step of reacting concentrated sulfuric acid and potassium sulfate with potassium chloride at about 300.degree. C. in a slurried state to obtain a mixed slurried salts of K.sub.n H.sub.2-n SO.sub.4 (n being 1.3 to 1.4); a second wet step of dissolving said mixed salts and additional raw potassium chloride in water, the amount of water being limited to some extent, heating the solution to 60.degree. to 90.degree. C. in order to take place a wet reaction, and cooling the solution to 50.degree. to 20.degree. C. to deposit potassium sulfate crystals from the solution in order to obtain the final product and filtrate; and a third circulating step of evaporating the filtrate to obtain a cake of mixed salts of acid potassium sulfate and potassium chloride, and returning circulatingly the cake to the first stage as part of raw materials.

Abstract: An apparatus is disclosed for producing an alkali metal salt of a mineral acid, characterized by the provision of a specific agitating means, said agitating means having a pair of shafts adapted to contra-rotate and a plurality of columnar agitating elements securely attached to each of said pair of shafts and being so constructed that it forcibly causes the migration of the reaction mixture at least in the region where the liquid phase of the reaction mixture is substantially continuous and forcibly causes the kneading of the reaction mixture at least in the region where the solid phase of the reaction mixture is substantially continuous.

Abstract: A small amount of chlorine contained in the converted potassium sulfate obtained by dry-mixing and heating potassium chloride with sulfuric acid or potassium hydrogensulfate can greatly be reduced by totally pulverizing the potassium sulfate to 60 mesh pass, and then calcining at 300.degree. to 500.degree. C. for 5 minutes to one hour. The chlorine content is further reduced by adding a small amount of water or dilute sulfuric acid prior to calcination.

Abstract: The advantages of the serial application of chlorine dioxide and chlorine without intermediate wash during the bleaching of wood pulp in the absence of significant amounts of dissolved organic materials are improved by the presence of small quantities of dissolved chlorine in the chlorine dioxide solution.

Abstract: Alkali metal sulfates are produced from an aqueous solution containing alkali metal hydrogen sulfate which comprises contacting the aqueous solution of alkali metal hydrogen sulfate with a hydrophilic solvent, the hydrophilic solvent being effective to extract at least a portion of the sulfuric acid formed as the alkali metal hydrogen sulfate is converted to alkali metal sulfate in the solution, together with at least a portion of the water present; permitting the alkali metal sulfate solid to crystallize; and recovering the solid alkali metal sulfate product. The hydrophilic solvent may then be extracted and separated from the sulfuric acid with a hydrophobic solvent and both solvents can be recovered and recycled.

Abstract: An improved apparatus for producing potassium sulfate and hydrogen chloride gas from potassium hydrogen sulfate and potassium chloride is provided, which comprises a horizontal type muffle furnace having an arcuate upper wall, at least one shaft of an agitator, a means for feeding raw materials, and a means for discharging the reaction product, to discharge the product by overflow; and an outer casing for said muffle furnace in which said furnace is accomodated on a bed of an insulating material and a space over said furnace, as a passage for heating gas. A heating gas introduced into said space over said furnace supplies the heat quantity required for the total reaction, through the upper wall of the furnace to raw materials. According to this apparatus, the life of furnace for continuous operation can be prolonged.

Abstract: The advantages of the serial application of chlorine dioxide and chlorine without intermediate wash during the bleaching of wood pulp in the absence of significant amounts of dissolved organic materials are improved by the presence of small quantities of dissolved chlorine in the chlorine dioxide solution.

Abstract: A process for converting chloride salts and sulfuric acid to sulfate salts and elemental chlorine is disclosed. A chloride salt and sulfuric acid are combined in a furnace where they react to produce a sulfate salt and hydrogen chloride. Hydrogen chloride from the furnace contacts a molten salt mixture containing an oxygen compound of vanadium, an alkali metal sulfate and an alkali metal pyrosulfate to recover elemental chlorine. In the absence of an oxygen-bearing gas during the contacting, the vanadium is reduced, but is regenerated to its active higher valence state by separately contacting the molten salt mixture with an oxygen-bearing gas.

Abstract: There is disclosed, in a process for separating zirconium and hafnium, an improvement for the removal of sodium sulfate from a sulfate-containing sodium chloride solution. This improvement includes adding a water-miscible organic precipitant such as methanol, ethanol or acetone to the sulfate-containing sodium chloride solution. The precipitant is added in an amount sufficient to cause the removal of sulfate as sodium sulfate. The organic precipitant is removed and the substantially sulfate ion free sodium chloride solution is recycled. Also provided is a process for the recovery of sodium sulfate having a purity greater than 99.9%.

Abstract: A method of producing potassium sulfate consists in conversion of sodium sulfate with potassium chloride in an aqueous medium to yield glaserite and a glaserite solution. Then, the glaserite is decomposed with potassium chloride in water to obtain potassium sulfate and a sulfate solution which is returned to the first stage of conversion. The glaserite solution is cooled at temperatures ranging from +3.degree. to -8.degree. C., whereby mirabilite and a chloride solution are formed, the latter being evaporated to obtain sodium chloride and a concentrated chloride solution. Finally, the concentrated chloride solution is mixed with mirabilite, and the resulting suspension is delivered to the first stage of conversion of sodium sulfate with potassium chloride. The proposed method permits producing high-quality potassium sulfate with full utilization of the return solutions. The yield of potassium sulfate reaches 98.6% at a K.sub.2 O content of up to 53% by weight.

Abstract: A method of beneficiating a mixed salt mineral ore containing potassium and magnesium sulfates and/or their hydrates which allows the recovery of anhydrous magnesium chloride and the simultaneous recovery of commercially acceptable potassium sulfate.

Abstract: A process for selectively recovering coarse crystalline K.sub.2 SO.sub.4 from a crystallizer is disclosed. A classifier comprising an elongated cylindrical vessel which is located separate from the crystallizer is employed in the process. Crystallization is effected in the crystallizer and supernatant liquor recovered as overflow during crystallization is passed from the crystallizer into the lower portion of the elongated cylindrical vessel. Slurry is recovered from the bottom of the crystallizer and introduced into a middle portion of the elongated cylindrical vessel. Coarse crystalline K.sub.2 SO.sub.4 falls to the bottom of the elongated cylindrical vessel and is recovered therefrom. Fine crystalline K.sub.2 SO.sub.4 is entrained in the upwardly flowing liquor and passed upwardly therewith. The upwardly flowing liquor and fine crystalline K.sub.2 SO.sub.4 are withdrawn from the top of the elongated cylindrical vessel and recycled to the crystallizer.

Abstract: In the process for the production of chlorine and alkali metal hydroxide by electrolysis according to the amalgam process using calcium- and/or sulphate containing crude salt, the calcium and/or sulphate contents introduced into the brine circuit by the crude salt are removed from the brine by precipitation of the double salt Na.sub.2 SO.sub.4 . CaSO.sub.4. Small particles of glauberite may be introduced to the brine to initiate and accellerate precipitation.

Abstract: Chlorine dioxide and chlorine are produced by reduction of sodium chlorate with chloride ions in an aqueous acid medium having a total acid normality of 2 to 4.8 normal. The reaction medium is maintained at its boiling point under a subatmospheric pressure to provide steam dilution of the chlorine dioxide and chlorine and anhydrous neutral sodium sulphate is deposited therefrom. Chlorine dioxide is recovered as an aqueous solution containing some dissolved chlorine while the bulk of the chlorine is recovered in gaseous form.

Abstract: An improved process is provided for the production of chlorine dioxide and chlorine wherein an alkali metal chlorate and a strong acid selected from the group sulfuric acid, hydrochloric acid, phosphoric acid, and mixtures thereof are circulated and reacted in an integral forced circulation crystallizing reaction evaporator comprising in vertical disposition:a. an upper crystallizing evaporation chamber having a substantially vertically disposed cylindrical partition which divides at least the lower portion of the reaction evaporation chamber into a first and second substantially concentric cylindrical sections;B. a heat exchange chamber, andC. a lower pump chamber, having a pump means disposed therein to provide forced circulation of fluids within the reaction evaporator.An aqueous slurry of alkali metal salt of the strong acid is withdrawn from the lower portion of the pump chamber and chlorine dioxide, chlorine, and water vapor are withdrawn from the evaporation chamber.

Abstract: An improved process for the production of chlorine dioxide wherein an alkali metal chlorate and a mineral acid are reacted in a single vessel, and the resultant alkali metal salt is converted to a more desirable salt in a metathesis column by reaction with an appropriate acid or an alkaline earth or alkali metal, chloride.

Abstract: An improved process for the production of chlorine dioxide wherein an alkali metal chlorate and a mineral acid are reacted in a single vessel, and the resultant alkali metal salt is converted to a more desirable salt in a metathesis column by reaction with an appropriate acid or an alkaline earth or alkali metal, chloride.

Abstract: Potassium sulfate (K.sub.2 SO.sub.4) is prepared by reaction of potassium chloride and sulfuric acid in an aqueous medium by initially removing evolved HCl in the gaseous form at temperatures of about 65.degree.-120.degree. C., then removing the remaining HCl as an HCl/water azeotrope at temperatures of about 90.degree. to 110.degree. C., restoring to the reaction mixture the amount of water removed with the azeotrope, and permitting the potassium sulfate to crystallize from the solution.

Abstract: Potassium sulfate (K.sub.2 SO.sub.4) is prepared by contacting potassium chloride with an aqueous solution containing potassium bisulfate at a temperature of about 65.degree.-110.degree. C., cooling the solution and permitting the potassium sulfate to crystallize from solution.

Abstract: An improved process for the production of chlorine dioxide wherein an alkali metal chlorate and sulfuric acid are reacted in a single vessel, and the resultant alkali metal sulfate converted to alkali metal chloride in a metathesis column by reaction with hydrochloric acid.

Abstract: Pigment TiO.sub.2 is prepared from sodium titanate by mixing with sulfuric acid, calcining at from 600.degree. to above about 900.degree.C, thereafter quenching in water, dissolving out the soluble sodium sulfate and recovering TiO.sub.2. By operating at 900.degree.C and above, artificial rutile is obtained. Instead of sulfuric acid, other mineral acids, their anhydrides, ammonium and alkali metal acid salts of said acids and borax may be employed.

Abstract: There is provided an improved process for the production of chlorine dioxide wherein an alkali metal chlorate, and a mineral acid are reacted in a single vessel, and the salt crystals separated from the generator crystal slurry.

Abstract: A process for the production of chlorine dioxide and a sulfate salt comprising mixing an aqueous solution of a chlorate, sulfuric acid and sulfur dioxide, reacting said mixture under reduced pressure near the boiling point of said solution at a temperature of 50.degree. to about 95.degree. centigrade to generate chlorine dioxide, removing water from the chlorate solution as water vapor with the generated chlorine dioxide, feeding replenishing amounts of aqueous chlorate to said reaction mixture to increase the concentration of the cation of said chlorate so as to have it exceed the saturation point of the sulfate of said cation under said reaction conditions, crystallizing a sulfate salt of said cation from said reaction mixture and recovering said sulfate salt.