Abstract: Modified starch compositions and their use for flocculating mineral waste residues, particularly the red mud containing alumina liquors from bauxite residues, comprising the addition to an alumina liquor of a flocculating amount of a methylated starch which, optionally, may be hydrolyzed, or a methylated starch which is also sulfonated and, optionally, may be hydrolyzed. Preferably, the methylated starch compositions are potato and dasheen starch derivatives prepared at temperatures of about 50.degree. to about 85.degree. C.

Abstract: Fluoride-containing wastes, arising in the aluminium industry, particularly spent cell linings from reduction cells, are digested with caustic soda for conversion of sodium cryolite to NaF.By use of very strong caustic soda NaF may be left in the solid residues after removal of the residual liquor and recovered from such residues by water leaching.As an alternative weaker caustic soda may be used in the digestion stage and subsequently be crystallised out from the residual liquor, after separation from the solid residues, by evaporating and/or cooling the liquor. The precipitated NaF is then conventiently redissolved in water.The NaF solution prepared by either route is then preferably subjected to electrodialysis to recover a solution of HF from it. Such HF is conveniently converted to AlF.sub.3 by reaction with alumina.

Abstract: A soluble salt (sodium sulfate or sodium borate (Na.sub.2 SO.sub.4 or Na.sub.2 B.sub.4 O.sub.7) contained as the main component in a concentrated radioactive waste liquid generated in the BWR power plant or the PWR power plant is insolubilized and precipitated, sodium hydroxide (NaOH formed in the insolubilization is separated from the precipitate and the radioactive waste liquid slurry containing the precipitate is solidified with a hydraulic solidifying material. Since the separated caustic soda (NaOH) is free of radioactive substances, it can be easily utilized again, and since the radioactive substances are stably fixed in the solidified body, leakage of radioactivity from the solidified body can be greatly reduced.

Abstract: A volume-reducing solidification treatment method for radioactive waste liquid containing boron primarily in the form of boric acid or borates is disclosed.After an alkali is added to the waste water to adjust pH thereof, and optionally after evaporation concentration is carried out, soluble calcium compounds such as Ca(OH).sub.2 are added, the waste water is stirred at a specific temperature to form insoluble calcium borate aged at a lower temperature than that of forming borate, and evaporation and concentration is carried out, which raises the concentration of the solid component. The concentrated liquid obtained is solidified with cement.The concentrated liquid may also be dried into a powder using a thin film evaporator.

Abstract: The present invention relates to a method and an apparatus for producing a waste package of radioactive waste containing particles of radioactive waste material of low modulus of elasticity, particles of radioactive waste material of high modulus of elasticity, and a solidifying agent in which the particles of radioactive waste material of low modulus of elasticity and the particles of radioactive waste material of high modulus of elasticity are fixed in an almost uniformly dispersed state. According to this invention, the radioactive waste generated from nuclear power plants can be greatly reduced in volume and also a waste package of radioactive waste with high strength and excellent water resistance can be obtained.

Abstract: A process for the stripping of cesium ions from an aqueous solution in which a precipitation agent is added to the aqueous solution and the resulting precipitate, containing the CS.sup.+ ions is stripped from the solution. Sodium or lithium tetraphenylborates, carrying electron-attracting substituents on the phenyl rings are employed as precipitation agent.

Abstract: Cesium chloride is recovered from used density gradient solutions by extraction of lipophilic and coloring components using a lipophilic solvent, subsequent extraction with a polar protic organic solvent, adding perchlorate ions to the extraction residue, and converting the precipitated cesium perchlorate into cesium chloride.

Abstract: A method for recovering useful animal feed supplements and a purefied brine from saline waters, such as oil and gas field brine wastes, involving the steps of adding an oxidizing agent to the brine to convert the divalent ferrous ions in the brine to ferric ions, then adding phosphoric acid in an amount approaching the stoicheometric equivalent of the divalent calcium ion the brine, then raising the pH of the brine to between 9 and 10 utilizing a material selected from the group consisting of sodium hydroxide or a mixture of sodium hydroxide and sodium carbonate followed by filtration to extract the feed supplement and thereafter adding a sufficient amount of hydrochloric acid to bring the pH to 7 and then crystallizing the sodium chloride from the resultant purefied brine solution.

Abstract: Cesium is recovered from a cesium-bearing mineral such as pollucite by roasting with an alkaline flux to convert the cesium to a soluble salt, extracting the cesium salt with water, and separating the cesium solution from the residual solids. Water-soluble permanganate is then added to the cesium solution to selectively precipitate cesium permanganate, giving other soluble metal compounds in solution. Cesium permanganate of high purity is recovered by separation from the residual solution. The cesium permanganate can be converted to other cesium compounds.

Abstract: A process is disclosed for removing heavy metal contaminants from impure alkali metal nitrates containing them. The process comprises mixing the impure nitrates with sufficient water to form a concentrated aqueous solution of the impure nitrates, adjusting the pH of the resulting solution to preferably within the range of between about 2 and about 4, adjusting the nitrite ion concentration to between about 0.07 molar and about 1.0 molar, to effect reduction of the heavy metal contaminants, adjusting the pH of the reduced solution to effect precipitation of heavy metal impurities, and separating the solid impurities from the resulting purified aqueous solution of alkali metal nitrates. The resulting purified solution of alkali metal nitrates may be heated to evaporate water therefrom to produce purified molten alkali metal nitrate suitable for use as a heat transfer medium. If desired, the purified molten form may be granulated and cooled to form discrete solid particles of alkali metal nitrates.

Abstract: Cuprous chloride, which is contained in a reduced leach solution or pregnant liquor, can be recovered as a complex salt of alkali metal chloride, such as potassium chloride, or alkaline earth metal chloride or ammonium chloride. The salts are produced by oxidation of a copper ore, such as chalcopyrite, with ferric chloride and cupric chloride, and after removal of insolubles, by adding sufficient metallic copper to the solution to reduce cupric ions to cuprous ions so as to provide a solution containing 1.5 to 2.5 molal potassium chloride, or other metal or ammonium chloride, and cooling the resultant saturated solution to precipitate the potassium chloride-cuprous chloride complex salts and recovering the complex salts. Also provided as a method for recovery of pure copper metal by electrolysis of solutions derived from the complex salts wherein the impurities are diverted to an anode loop which is separated from the cathode loop by a diaphragm.

Abstract: An apparatus is disclosed for dissolving salt in an undersaturated brine to bring the brine up to saturation conditions. A salt slurry, specifically sodium chloride, is brought into a holding tank and recycled to keep the solids suspended in the liquid. Part of the recycling salt stream is diverted to a saturator unit consisting of an upright column and a slurry feed tube mounted inside and coaxial with the column. The slurry passes downwardly through the feed tube and mixes with an undersaturated brine stream entering through the bottom of the column. This mixture flows upwardly through an annulus section defined between the feed tube and saturator column, with the salt dissolving in the brine during the upward flow. Saturated brine is removed at the top of the column for ultimate use, such as in chlorine cells.

Abstract: A process is disclosed for removing heavy metal contaminants from impure alkali metal nitrates containing them. The process comprises mixing the impure nitrates with sufficient water to form a concentrated aqueous solution of the impure nitrates, adjusting the pH of the resulting solution to within the range of between about 2 and about 7, adding sufficient reducing agent to react with heavy metal contaminants within said solution, adjusting the pH of the solution containing reducing agent to effect precipitation of heavy metal impurities and separating the solid impurities from the resulting purified aqueous solution of alkali metal nitrates. The resulting purified solution of alkali metal nitrates may be heated to evaporate water therefrom to produce purified molten alkali metal nitrate suitable for use as a heat transfer medium. If desired, the purified molten form may be granulated and cooled to form discrete solid particles of alkali metal nitrates.

Abstract: Anhydrous zinc chloride is produced from an aqueous feed solution containing zinc chloride from an aqueous feed solution containing zinc chloride. The zinc chloride is extracted onto an organic extractant known to the art such as tributyl phosphate, primary, secondary or tertiary amines, and quaternary amine salts. The loaded extractant is then stripped with aqueous stripping solution containing ammonium chloride and ammonium hydroxide. The zinc ammine chloride formed in this aqueous stripping solution is separated from the stripping solution and can then be heated to form anhydrous zinc chloride and ammonia. This anhydrous zinc chloride is suitable as a feed material to a fused salt electrolysis process for the production of zinc.

Abstract: A method for destroying toxic organic chemical products. The method is particularly adapted for the destruction of polyhalogenated polyphenyls, especially polychlorinated biphenyls (PCBs). The toxic organic chemical product is intimately contacted and reacted with a molten mixture of an alkali metal hydroxide and an alkali metal nitrate, so that it is converted to harmless products which, in the case of PCBs, include a halide salt, at least one carbon oxide, and water. By incorporating a substantial excess of nitrate in the mixture most of the salt is caused to precipitate and to settle out to the bottom for easy removal.

Abstract: The products of a molten salt combustion of hazardous wastes are converted into a cooled gas, which can be filtered to remove hazardous particulate material, and a dry flowable mixture of salts, which can be recycled for use in the molten salt combustion, by means of gas/liquid contact between the gaseous products of combustion of the hazardous waste and a solution produced by quenching the spent melt from such molten salt combustion.The process results in maximizing the proportion of useful materials recovered from the molten salt combustion and minimizing the volume of material which must be discarded. In a preferred embodiment a spray dryer treatment is used to achieve the desired gas/liquid contact.

Abstract: Cesium is recovered from cesium alum, CsAl(SO.sub.4).sub.2, by an aqueous conversion and precipitation reaction using a critical stoichiometric excess of a water-soluble permanganate to form solid cesium permanganate (CsMnO.sub.4) free from cesium alum. The other metal salts remain in solution, providing the final pH does not cause hydroxides of aluminum or iron to form. The precipitate is separated from the residual solution to obtain CsMnO.sub.4 of high purity.

Abstract: Cesium is recovered from cesium alum, CsAl(SO.sub.4).sub.2, by a two-reaction sequence in which the cesium alum is first dissolved in an aqueous hydroxide solution to form cesium alum hydroxide, CsAl(OH).sub.3, and potassium sulfate, K.sub.2 SO.sub.4. Part of the K.sub.2 SO.sub.4 precipitates and is separated from the supernatant solution. In the second reaction, a water-soluble permanganate, such as potassium permanganate, KMnO.sub.4, is added to the supernatant. This reaction forms a precipitate of cesium permanganate, CsMnO.sub.4. This precipitate may be separated from the residual solution to obtain cesium permanganate of high purity, which can be sold as a product or converted into other cesium compounds.

Abstract: Cesium is recovered from a cesium-bearing mineral such as pollucite by extraction with hydrochloric acid to obtain an extract of cesium chloride and other alkali metal and polyvalent metal chlorides. The iron and aluminum chlorides can be precipitated as the hydroxides and separated from the solution of the alkali metal chlorides to which is added potassium permanganate or other water-soluble permanganate to selectively precipitate cesium permanganate. The cesium precipitate is then separated from the residual solution containing the metal chlorides. The cesium permanganate, which is in a very pure form, can be converted to other cesium compounds by reaction with a reducing agent to obtain cesium carbonate and cesium delta manganese dioxide.

Abstract: A process is disclosed for purifying aqueous solutions of metal hydroxides.An aqueous solution of a metal hydroxide, such as sodium hydroxide, containing a complex of a heavy metal contaminant, such as mercury, is heated.An oxidizing agent, such as hydrogen peroxide, is reacted with the solution to precipitate solid particles of an oxide of the heavy metal, for example, mercuric oxide, in a solution. The solid particles of mercuric oxide are separated from the solution by filtration.The purified solution comprised of water and sodium hydroxide and containing less than about 0.3 part per million mercury by weight is sold commercially. The solid particles of mercuric oxide are landfilled or otherwise utilized.

Abstract: A purification of an aqueous solution of potassium chloride which is used for producing potassium hydroxide by an electrolysisin an electrolytic cell using a cation exchange membrane is carried out by incorporating an oxidizing reagent to remove additives as an anticaking reagent.

Abstract: A method of purifying alkali metal chloride brine containing calcium ion impurities which comprises adding to the brine a proportion of an alkali metal carboxylate compound to form an insoluble calcium carboxylate precipitate, separating the insoluble carboxylate precipitate from the brine to purify the brine and recovering the resulting purified brine. The alkali metal carboxylate compound has the formula: ##STR1## wherein Me is an alkali metal and n is an integer from 0 to 6.

Abstract: Disclosed is an improved method of producing potassium chloride by concentrating a brine thereof with respect to potassium chloride by multiple stage evaporation conducted at progressively higher temperatures, thereby precipitating other salts and thereafter cooling the brine in multiple stage crystallizers operated at progressively lower temperatures, thereby precipitating potassium chloride crystals. The improvement comprises cooling the brine in hotter crystallizer utilizing streams to or between cooler evaporators whereby in addition heat is provided to the evaporator stream.

Abstract: Disclosed is a method of recovering lithium ion from a lithium-containing solution by electrolyzing the solution between a cathode and an aluminum anode.

Abstract: A process for reducing the sodium chloride content of crystalline potassium salts without the use of successive recrystallization. The crystalline potassium salts having a sodium chloride content greater than about 0.8 percent by weight are subjected to compacting and crushing to provide a crystalline product having an average particle diameter less than 1.6 millimeters. The crystalline product is leached with a brine at least about 80 percent saturated with said potassium salt and less than 50 percent saturated with sodium chloride to produce a crystalline potassium salt product containing less than about 0.35 percent by weight of sodiumchloride.

Abstract: Magnesium chloride can be recovered in high yield and in high purity from brines containing both magnesium chloride and alkali metal chlorides, by adding dioxane to the brine, separating the resultant precipitate from the brine and separating the dioxane contained in the precipitate from the latter.

Abstract: Crude sodium hexafluorosilicate containing gypsum and various metal phosphates is refined into highly pure and sufficiently large crystals. First, the crude fluorosilicate is treated with a sodium chloride solution to dissolve gypsum. Then the solid phase is reconstituted into an aqueous slurry in which the concentration of Na is limited. This slurry is acidified and maintained at temperatures not lower than 80.degree. C. with continued stirring to cause recrystallization of sodium hexafluorosilicate.

Abstract: Crude sodium hexafluorosilicate containing gypsum as a principal impurity can be refined economically with a minimized loss of fluorine by first making the crude fluorosilicate in the form of an aqueous slurry react with an alkali metal compound such as sodium carbonate or sodium hydroxide to form a soluble sulfate, and then treating the solid component of the reaction product with an acid solution in the presence of sodium ion, preferably at elevated temperatures near boiling point, to form a soluble calcium salt and crystallize sodium hexafluorosilicate. Sea water may be used both as the aqueous medium for the slurry in the first step and as the source of the sodium ions in the second step.

Abstract: Floride and aluminum values, as well as carbon, are recovered from waste cathode liner material from aluminum electrolytic cells by leaching of the liner at ambient temperature with a caustic solution, followed by precipitation of sodium fluoride by saturating the leach liquor with a compound which suppresses the solubility of sodium fluoride in the leach liquor. Ammonia is a preferred compound. Aluminum compounds, as well as the carbon values, are also recovered. Treating chemicals used in the process are recycled. The process is essentially a closed-cycle process with substantially no discharge of effluent.

Abstract: The content of sodium sulfate (and less soluble sulfates) in rock salt (halite) can economically be reduced from levels as high as 5 weight percent to levels as low as about 0.1 weight percent by the process of the invention. The halite is crushed to a certain particle size range and particles less than 0.5 mm in effective diameter are removed while (or after) the crushed material is subjected to attrition washing with a low sulfate, high NaCl brine. The washed, coarse particles are rinsed with a low sulfate brine, drained and dried to an extent appropriate to their contemplated use.

Abstract: Aqueous process streams or waste waters destined for merging with public waters sometimes contain deleterious amounts of heavy metals, e.g., lead (Pb) compounds. The heavy metal compounds may be substantially removed or reduced to harmless levels by treating the acidic aqueous streams with chromate or dichromate ions, then heating the solution to oxidize organics and/or heavy metal-organics, then raising the pH to an alkaline pH to precipitate the heavy metal chromate, and separating the heavy metal chromate from the aqueous stream.

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

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

Abstract: A process for preparing from aqueous NaCl brine containing appreciable quantities of dissolved calcium sulfate high purity dendritic salt, characterized by an exceptionally low calcium sulfate content. The process is carried out by a "feed and bleed" procedure comprising admixing an alkali metal polyphosphate with said brine to increase the supersaturation of calcium sulfate therein, feeding the brine containing this additive into an evaporating and crystallizing chamber, evaporating the brine at an elevated temperature and reduced pressure to cause crystallization of pure salt and concomitantly bleeding brine from the chamber, the rate of feed of the brine to the chamber and the rate of bleed of brine from the chamber being such as to maintain the calcium sulfate in the dissolved state and prevent its precipitation with the salt.

Abstract: In the process of making sodium carbonate from trona involving the steps of crushing the trona, calcining the crushed trona, dissolving the calcined trona to obtain a solution comprising sodium carbonate and insoluble impurities contaminated by soluble silicates and soluble carbonaceous matter, contamination of the sodium carbonate solution with soluble carbonaceous matter is reduced by the improvement which comprises calcining the crushed trona at temperature of 300.degree. C. to 600.degree. C. in the presence of magnesium oxide. When the trona is calcined in the presence of magnesium oxide at temperature of 350.degree. to 600.degree. C., then the sodium carbonate solution is low in both soluble carbonaceous matter as well as insoluble silicates.

Abstract: In the process for making sodium carbonate from trona, the soluble silicate content of crystallizer mother liquor from which sodium carbonate precursor crystals are obtained by evaporative crystallization is reduced by the method which comprises:1. digesting said mother liquor at elevated temperature for time sufficient to reduce soluble silicates, in the presence as treating agent of insolubles which have been obtained by (a) calcination of crushed trona, (b) segregation of a fine particle size fraction from the calcined trona, (c) dissolution of said fine particle size fraction in an aqueous medium to obtain a solution comprising sodium carbonate and insolubles, followed by (d) separating insolubles, and2. separating the insolubles from the digested mother liquor, and recycling the mother liquor to the process.

Abstract: In the process of making sodium carbonate from trona by the method involving crushing the trona, calcining it and dissolving it in an aqueous medium for purification by crystallization, soluble silicate contamination of the crystallization liquor is reduced by an improvement which involves: (a) segregating the calcined trona into a coarse and a fine fraction; (b) separately dissolving the coarse and fine fractions to obtain aqueous solutions of sodium carbonate, sodium silicates and insoluble impurities; (c) optionally adding to the solution of the fine fraction insoluble impurities which have been separated from a solution of such fine fraction in a previous operation; followed by (d) digesting the solution of the fine fraction containing added insolubles at elevated temperature to insolubilize soluble silicates and separating the digested solution from insoluble impurities.

Abstract: In the process of making sodium carbonate from trona involving the steps of crushing the trona, calcining the crushed trona, dissolving the calcined trona to obtain a solution comprising sodium carbonate and insoluble impurities contaminated by soluble silicates and soluble carbonaceous matter, contamination of the sodium carbonate solution with soluble silicates is reduced by the improvement which comprises calcining the crushed trona at temperature of 200.degree. C. to 600.degree. C. in the presence of an additive selected from the group consisting of aluminum oxide and bauxite. When the trona is calcined in the presence of aluminum oxide or bauxite at temperatures of 350.degree. to 600.degree. C., then the sodium carbonate solution is low in both soluble silicate as well as carbonaceous matter.

Abstract: A process for the obtention of alumina and phosphate values by the alkaline decomposition of silica-containing aluminum phosphate ores comprises reducing the ore to a particle size of from about 6 to 13 mm; calcining the ore at a temperature of from 500.degree. to 750.degree. C in order to remove water of crystallization and combined water; grinding the calcined ore to a particle size of from 20 to 60 mesh (U. S. Sieve); treating the calcined and ground ore with an aqueous solution having a concentration of from 20 to 30% by weight caustic alkali at an initial temperature of from 65.degree. to 75.degree. C; quickly filtering the hot suspension thus obtained to remove the solid silica and heavy metal oxides; adding a 50% caustic alkali solution to the filtrate in an amount sufficient to obtain a total concentration of from 10 to 15% by weight of free caustic alkali; cooling the alkaline liquor accompanied by an elutriation action in an elutriator to a temperature of from 5.degree. to 10.degree.

Abstract: Thin film epitaxial layers of mixed oxide compounds, or of solid solutions of two mixed oxides, are deposited on a suitable single crystal substrate. Growth is achieved by introducing the substrate into a crucible containing a saturated solution of the oxide(s) in a molten alkali metal halide having additional undissolved oxide(s) present in the crucible. Evaporation of the alkali metal halide solvent produces and/or maintains the supersaturated condition, which is relieved by epitaxial deposition of the oxide(s) onto the substrate. When two mixed oxides are dissolved in the solvent, the composition of the film is determined and fixed by the temperature of growth. To produce a thin film of a constant composition, growth is conducted isothermally. To produce a thin film with a graded composition throughout its thickness, growth is conducted by slowly cooling the temperature of the solution.

Abstract: The present invention relates to an improved method of solution mining potassium chloride from subterranean ore deposits containing both potassium chloride and sodium chloride. By the present invention, an aqueous medium is passed through the ore deposits so that potassium chloride and sodium chloride are dissolved therein. Magnesium chloride is combined with the aqueous brine solution formed so that an aqueous brine solution containing potassium chloride, sodium chloride and magnesium chloride in specific proportions is produced, and the solubility of potassium chloride in the solution is reduced. The combined aqueous brine solution is then concentrated so that it is substantially saturated with potassium chloride, and the concentrated solution is cooled to cause the precipitation of substantially pure potassium chloride.

Abstract: The present invention relates to an improved method for the manufacture of potassium phosphates. More specifically the present invention provides a process for the manufacture of monopotassium phosphate, KH.sub.2 PO.sub.4, from potassium bearing brines.

Abstract: Soda values from the crystallizer mother liquor purge in the process of making sodium carbonate from trona are recovered by (1) mixing the purge with treating agent of magnesium oxide, aluminum oxide, bauxite, certain fine particle size calcined trona, insoluble impurities obtained in the trona-soda ash process, or mixtures thereof, (2) evaporating the resulting mixture to dryness and calcining it to insolubilize soluble silicates and to reduce contamination with carbonaceous impurities, and (3) leaching the calcined mixture with water or aqueous sodium carbonate solution.

Abstract: A method and apparatus for cooling aqueous alkali metal hydroxide liquors such as, for example, caustic soda liquors, involving the vacuum cooling of a body of such liquor in an evaporating chamber having a overhead vapor outlet which communicates with a direct-contact barometric condenser supplied with a stream of cooled alkali metal hydroxide liquor. The cooled alkali metal hydroxide liquor has a vapor pressure below the absolute pressure of water vapor evolved from the body of liquor in the evaporating chamber and condenses the water vapor upon contact therewith. A stream of cooled concentrated alkali metal hydroxide liquor withdrawn from the evaporating chamber is, in accordance with a preferred embodiment of the present invention, further cooled and solids contained therein, such as, for example, sodium chloride crystals, are then removed in a suitable liquid-solids separation device.

Abstract: Minute amounts of boron present in naturally occurring brines found in oceans, inland seas, salt lakes and the like are removed by treating the brine with a solid, finely divided lignite.

Abstract: This invention relates to a process for the treatment of the reaction mass produced during the joint elimination of barium-containing nitrite-/nitrate-bearing carburizing salt wastes and cyanide-/cyanate-bearing wastes by ignition of the dry mixture at elevated temperatures, comprising suspending the reaction mass in water and either (a) adding a water-soluble barium salt to the aqueous suspension in equimolar quantities, based upon carbonate ions, and separating precipitated barium carbonate, or (b) freeing the alkaline suspension from barium carbonate by filtration, reacting the filtrate with a water-soluble calcium salt, and separating precipitated calcium carbonate, concentrating the clear solutions obtained according to (a) or (b) to a water content of 10 - 20% by weight, separating precipitated sodium chloride, and evaporating the residual solution to dryness.

Abstract: Cesium is recovered from cesium alum, CsAl(SO.sub.4).sub.2, by a two-reaction sequence in which the cesium alum is first dissolved in an aqueous hydroxide solution to form cesium alum hydroxide, CsAl(OH).sub.3, and potassium sulfate, K.sub.2 SO.sub.4. Part of the K.sub.2 SO.sub.4 precipitates and is separated from the supernatant solution. In the second reaction, a water-soluble permanganate, such as potassium permanganate, KMnO.sub.4, is added to the supernatant. This reaction forms a precipitate of cesium permanganate, CsMnO.sub.4. This precipitate may be separated from the residual solution to obtain cesium permanganate of high purity, which can be sold as a product or converted into other cesium compounds.