Abstract: This disclosure relates to improved methods for alkali metal cyanide production, particularly to improved methods for sodium cyanide production. The improved method of producing sodium cyanide involves the step of contacting hydrogen cyanide with an aqueous solution of sodium carbonate or of a mixture of sodium carbonate and sodium bicarbonate to produce a sodium cyanide solution.

Abstract: An ozonation-based method for producing a cementitious material comprises the steps of: (1) mixing a flue gas with an ozone-containing gas to form a mixed flue gas; and introducing the mixed flue gas into an absorption tower, where the mixed flue gas undergoes dry desulfurization and denitrification by reacting with a powdered desulfurizing and denitrificating agent and becomes a treated flue gas; (2) subjecting the treated flue gas to dust removal to generate by-products; and (3) uniformly mixing raw materials that comprise the first by-product, magnesium oxide, fly ash and an additive to give a cementitious material, wherein on the basis of 100 parts by weight of the cementitious material, the first by-product is 20-60 parts by weight, magnesium oxide is 16-33 parts by weight, the fly ash is 15-35 parts by weight, and the additive is 1-15 parts by weight.

Abstract: A boundary layer carbonation process for producing sodium bicarbonate crystals having specific surface area in the range 0.4 m2/g to 2.5 m2/g from Trona, wherein in one embodiment the process comprises the steps of: providing Trona particles having a particle size range of ?4+120 mesh; pre-wetting the Trona particles with water to provide a plurality of pre-wetted Trona particles each having a liquid water solution boundary layer deposited thereon; and carbonating the pre-wetted Trona particles across the water boundary layer to provide a product comprising sodium bicarbonate crystals.

Abstract: Process for producing sodium carbonate and sodium bicarbonate in a continuous mode out of trona comprising: c) feeding crushed trona, an extraction water and an additive in a first leaching tank containing a dissolution solution comprising sodium carbonate and sodium bicarbonate, wherein the additive is selected from the group consisting of: anionic hexametaphosphate, anionic polyphosphate, anionic polyphosphonate, soja lecithine, anionic polycarboxylate polymer, anionic polyacrylate polymer, anionic polyacrylate-polyacrylamide co-polymer, anionic hydrolyzed polymaleic polymers, anionic maleic-acrylic acids copolymers, anionic acrylic acid-phosphonic acid copolymers and combinations thereof; d) dissolving at least partially the crushed trona in the dissolution solution in order to produce a first suspension; e) removing continuously the first suspension from the first leaching tank and feeding it with an additive into a second leaching tank wherein the additive is selected from the same group of additives of

Abstract: A boundary layer carbonation process for producing sodium bicarbonate crystals having specific surface area in the range 0.4 m2/g to 2.5 m2/g from Trona, wherein in one embodiment the process comprises the steps of: providing Trona particles having a particle size range of ?4 +120 mesh; pre-wetting the Trona particles with water to provide a plurality of pre-wetted Trona particles each having a liquid water solution boundary layer deposited thereon; and carbonating the pre-wetted Trona particles across the water boundary layer to provide a product comprising sodium bicarbonate crystals.

Abstract: Approaches for alkali metal extraction, sequestration and recovery are described. For example, a method of recovering alkali metals includes providing a CST or CST-like (e.g., small pore zeolite) material. The alkali metal species is scavenged from the liquid mixture by the CST or CST-like material. The alkali metal species is extracted from the CST or CST-like material.

Abstract: A solution mining method for recovering alkali values from a cavity of an underground ore formation comprising trona and/or wegscheiderite; a manufacturing process using such method to make sodium-based product(s); and a sodium-based product obtained therefrom. The method comprises: an ore dissolution phase (a) in which the incongruent double-salt in trona and/or wegscheiderite is dissolved from an ore face in a first solvent, and a cavity cleaning phase (b) in which sodium bicarbonate deposited on the ore face during the dissolution phase (a) is dissolved into a second aqueous solvent having a higher pH, hydroxide content, and/or temperature and is partly or completely converted in situ to sodium carbonate. The method further comprises withdrawing a liquor resulting from either phase to the ground surface, optionally recycling some liquor to the cavity; and passing some liquor through a crystallizer, a reactor, and/or an electrodialyser, to form at least one sodium-based product which is recovered.

Abstract: A boundary layer carbonation process for producing sodium bicarbonate crystals having specific surface area in the range 0.4 m2/g to 2.5 m2/g from Trona, wherein in one embodiment the process comprises the steps of: providing Trona particles having a particle size range of ?4+120 mesh; pre-wetting the Trona particles with water to provide a plurality of pre-wetted Trona particles each having a liquid water solution boundary layer deposited thereon; and carbonating the pre-wetted Trona particles across the water boundary layer to provide a product comprising sodium bicarbonate crystals.

Abstract: A process for formulating high purity potassium chloride from a carnallite source. The process takes advantage of solubility differences and saturation levels in a multiple salt system generated upon dissolution of carnallite. In the system, the sodium chloride is kept in solution and the magnesium chloride present in the system is controlled to be in a concentration range of between 12% and 25% by weight. This avoids co-precipitation of sodium chloride with the potassium chloride during crystallization and therefore prevents the sodium chloride from contaminating the potassium chloride. The result is high grade potassium chloride.

Abstract: A method for the controllable dissolution of one or more alkali metals from a vessel containing a one or more alkali metals and/or one or more partially passivated alkali metals. The vessel preferably comprising a sodium, NaK or other alkali metal-cooled nuclear reactor that has been used. The alkali metal, preferably sodium, potassium or a combination thereof, in the vessel is exposed to a treatment liquid, preferably an acidic liquid, more preferably citric acid. Preferably, the treatment liquid is maintained in continuous motion relative to any surface of unreacted alkali metal with which the treatment liquid is in contact. The treatment liquid is preferably pumped into the vessel containing the one or more alkali metals and the resulting fluid is extracted and optionally further processed. Preferably, the resulting off-gases are processed by an off-gas treatment system and the resulting liquids are processed by a liquid disposal system.

Abstract: A method for removing impurities from a waste solid to provide at least a portion of a suitable crystallizer feed to a process for making crystalline sodium carbonate, bicarbonate, and/or other derivatives. The method comprises: contacting the waste solid with a leach solution to dissolve at least one impurity and dissolving the resulting leached residue. Leaching may include heap percolation. The leach solution may comprise a crystallizer purge liquor, a process waste effluent, a mine water, or mixtures thereof. The method may further comprise adding a magnesium compound to the resulting leached residue during or after its dissolution to remove another impurity. The waste solid preferably comprises a pond solid containing such impurities. The pond solid may be recovered from a pond receiving crystallizer purge liquor(s) and/or other process waste effluent(s). The pond solid may contain sodium carbonate, any hydrate thereof, sodium bicarbonate, and/or sodium sesquicarbonate.

Abstract: A process for producing soda ash from brine waste, the process including reacting brine waste with carbon dioxide and ammonia to produce soda ash, where in at least a portion of the ammonia is regenerated from the ammonium chloride produced during the reaction, the regeneration ideally be achieved by the use of a weak base anion exchange resin.

Abstract: A photocatalyst having superior properties of adsorption and decomposition with respect to various substances is provided. This photocatalyst comprises a porous body coated with titanium apatite. The porous body is preferably diatomaceous earth. The photocatalyst can be formed by co-precipitation or a sol-gel method.

Abstract: A method for treating an oil shale formation comprising dawsonite includes providing heat from one or more heaters to the formation to heat the formation. Hydrocarbon fluids are produced from the formation. At least some dawsonite in the formation is decomposed with the provided heat. A chelating agent is provided to the formation to dissolve at least some dawsonite decomposition products. The dissolved dawsonite decomposition products are produced from the formation.

Abstract: A method for treating an oil shale formation comprising nahcolite includes providing a first fluid to a portion of the formation. A second fluid is produced from the portion. The second fluid includes at least some nahcolite dissolved in the first fluid. A controlled amount of oxidant is provided to the portion of the formation. Hydrocarbon fluids are produced from the formation.

Abstract: A method for treating a hydrocarbon containing formation is provided. In one embodiment, heat from one or more heaters may be provided to at least a portion of the formation. Heat may be allowed to transfer from the one or more heaters to at least a part of the formation. In certain embodiments, the heat from the one or more heaters may pyrolyze at least some hydrocarbons within the formation. In an embodiment, a first fluid may be introduced into at least a portion of the formation. The portion may have previously undergone an in situ conversion process. A mixture of the first fluid and a second fluid (or a second compound) may be produced from the formation. In some embodiments, a first fluid may be provided to the formation prior to pyrolyzing hydrocarbons in the formation, and a second fluid (or a second compound) may be produced prior to pyrolyzing hydrocarbons in the formation.

Abstract: An oil shale formation may be treated using an in situ thermal process. Heat may be provided to the treatment area. Fluids may be injected into the formation to remove a component within the formation. Hydrocarbons, H2, and/or other formation fluids may be produced from the formation. In some embodiments, fluids may be injected prior to production of formation fluids. Alternatively, fluids may be injected after production of formation fluids.

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 process is described for the treatment of spent pot lining material from electrolyte reduction cells, this spent material having a substantial content of cryolite. The spent material is first leached with water at a dilution and a time sufficient to dissolve substantially all water soluble fluorides, after which the solid residue is separated from the liquid. The solid residue obtained is then subjected to a caustic leach with an aqueous sodium hydroxide solution containing about 20 to 50 g/L of NaOH and thereafter the solid residue is separated from the liquid.

Abstract: Ash from a recovery boiler is purified by leaching or evaporation-crystallizing contaminants such as, chlorides and potassium salts in water. The leaching or evaporation-crystallizing takes place in an aqueous solution at a temperature that is in the vicinity of the boiling point of the aqueous solution. The leached or evaporation-crystallized ash is returned to the black liquor or to the recovery boiler while the leaching water or the evaporation-crystallization water is then cooled to less than 32.degree. C., preferably 10-15.degree. C. Sodium sulphate containing crystallization water, such as sodium sulphate heptahyfdrate or sodium sulphate decahydrate, is crystallized out and then separated to be reintroduced into the black liquor, directly into the recovery boiler or into the leaching solution or evaporation-crystallization solution.

Abstract: This invention relates to a process for removing sodium chloride and potassium salts, which are impurities concentrated and accumulated in pulp digesting chemicals, from ash collected from a soda recovery boiler. This process comprises the steps of (a) mixing ash collected from the combustion exhaust gas of the soda recovery boiler with water to form a slurry, adjusting the pH of the slurry to 10 or less by the addition of sulfuric acid, adjusting the temperature of the slurry to 20.degree. C. or above, and holding the slurry at that temperature for a sufficient time to cause sodium chloride and potassium salts present in the collected ash to be dissolved in the water; (b) cooling the slurry to a temperature below 20.degree. C. by the addition of ice and/or water so as to precipitate solid matter therefrom; and (c) separating the slurry into solid and liquid components and recovering the solid component while discharging the liquid component out of the system.

Abstract: There is disclosed a process for denitrifying tobacco materials and removing barium from tobacco materials, comprising mixing an aqueous-immiscible organic solvent containing a crown ether with an aqueous solution containing soluble components from tobacco materials, agitating this mixture, and separating the organic phase containing a crown ether-cation-nitrate (or nitrite) complex from the aqueous phase containing the denitrified tobacco materials, wherein the cation consists essentially of barium and potassium. There is further disclosed a process for eliminating tobacco-specific nitrosamines (TSNAs) from cured, denitrified tobacco material, comprising contacting the denitrified tobacco material with a trapping sink, wherein the trapping sink comprises a select transition metal complex which is readily nitrosated to form a nitrosyl complex with little kinetic or thermodynamic hindrance.

Abstract: This invention relates to the preparation of cesium salts from cesium-aluminum-alum in a process in which the cesium-aluminum-alum is reacted in a single vessel in the presence of water with calcium hydroxide in an amount which is equimolar to the amount of aluminum and with a readily water-soluble calcium salt in an amount which is equimolar to the amount of cesium and the precipitated aluminum hydroxide and the precipitated calcium sulfate are separated by filtration or centrifugation.

Abstract: A method is provided for the regeneration of a scavenging compound that has been reacted with hydrogen sulfide. Regeneration is accomplished through the use of calcium oxides and sodium hydroxide. Sodium sulfide is recovered from the regeneration process in a commercially useful form. Calcium oxides are also regenerated in the process, allowing for minimal or no chemical waste.

Abstract: In a process for recovering an alkali metal azide from a waste gas generating material containing the alkali metal azide and a metal oxide reactable with the azide, the gas generating material is mixed with a solvent for the alkali metal azide. This produces a slurry comprising (i) a solution comprising the solvent and the alkali metal azide, and (ii) the metal oxide. The slurry is separated into a liquid stream comprising primarily the solution and a sludge stream comprising primarily the metal oxide. The liquid stream is filtered in a filter to produce a filtrate which is substantially free of metal oxide and is then concentrated by evaporation of the solvent to produce crystals of the alkali metal azide. The separation may be carried out by a filter or centrifuge to produce a filter or centrifuge cake. The sludge obtained from the slurry is reslurried to recover additional azide, and the resulting slurry is again separated into a sludge and a liquid stream by a filter or centrifuge.

Abstract: A process and system for treating aluminum salt cake containing water soluble halide salts by contacting the salt cake with water to dissolve water soluble halide salts forming a saturated brine solution. Transporting a portion of about 25% of the saturated brine solution to a reactor and introducing into the saturated brine solution at least an equal volume of a water-miscible low-boiling organic material such as acetone to precipitate a portion of the dissolved halide salts forming a three-phase mixture of an aqueous-organic-salt solution phase and a precipitated salt phase and an organic rich phase. The precipitated salt phase is separated from the other phases and the organic rich phase is recycled to the reactor. The remainder of the saturated brine solution is sent to a multiple effect evaporator having a plurality of stages with the last stage thereof producing low grade steam which is used to boil off the organic portion of the solution which is recycled.

Abstract: Process for disposing of insoluble tailings that remain when solubilizing uncalcined or calcined trona in the process of producing soda ash, in which the tailings are slurried with water or waste solutions of sodium carbonate and/or sodium bicarbonate, adding an alkali metal hydroxide or alkaline earth metal hydroxide in effective amounts up to about 10% by weight of the aqueous slurrying solution, pumping the slurry into a well connected to an underground mined-out cavity with sufficient pressure to prevent build-up of tailings from plugging the bottom of the well opening, dispersing and settling said tailings in the cavity, removing a liquor from said cavity whose concentration of sodium carbonate and/or sodium bicarbonate has been increased and recovering such enriched liquor for use in the manufacture of sodium-containing chemicals such as soda ash.

Abstract: A process for recovery of metallic aluminum, sodium and potassium chloride and an aluminum oxide-metallic aluminum product from secondary aluminum dross. A secondary aluminum dross feed is separated by particle size into a first dross portion which is water leached, filtered, evaporated in an evaporator to produce crystallized sodium and potassium chloride salts, magnesium chloride remaining in solution. A purge stream is removed from the evaporator wherein the crystallized salts are separated therefrom. The purge stream is then discharged onto the crystallized salts.

Abstract: Disclosed is a method of reducing the sodium chloride content of potassium chloride by forming an aqueous slurry of potassium chloride feed crystals having a wide particle size distribution with an average diameter of about 0.1 to about 50 microns in a liquor saturated with potassium chloride and undersaturated with sodium chloride, which is at least 50% saturated with sodium chloride, whereby the smaller of the feed crystals dissolve and potassium chloride grows on the larger of the feed crystals to form product crystals removing the product crystals from the slurry. Also disclosed is an apparatus for carrying out this process.

Abstract: A process for recovering purified cesium chloride from a cesium aluminum silicate ore in which the ore is digested with aqueous hydrochloric acid and the silica solids removed to obtain an aqueous acidic digest solution of metal chlorides consisting of cesium chloride together with other metal chlorides, by(a) evaporating water from the digest solution to obtain a solid mixture of metal chlorides, including cesium chloride and hydrated aluminum chloride;(b) heating solid phase mixture at a temperature effective for converting the hydrated aluminum chloride to aluminum oxide without decomposing the cesium chloride;(c) extracting the resulting solids with water to obtain an aqueous extract of cesium chloride; and(d) separating the residual solids containing the aluminum oxide to produce a purified extract of cesium chloride.

Abstract: A process for making a dry metal halide salt which will not form an insoluble flocculent material upon dissolving in water in which an initial aqueous solution of a metal halide salt is prepared and a member selected from the group consisting of ammonium chloride, ammonium bromide, borate anion producing compounds and mixtures thereof is added. Water is then evaporated from the initial aqueous solution and a dry metal halide salt is obtained. Upon dissolving this dry metal halide salt in water a clear, colorless solution results which does not contain an insoluble flocculent material. Alternatively, the member compound may be added to the dry metal halide salt, before it is dissolved in water or the member compound may be added to the water which is used to dissolve the dry metal halide salt.

Abstract: Alkali metal phosphates are recovered from a water immiscible solvent solution of aqueous wet process phosphoric acid by neutralizing the acid with a basic alkali metal salt in a ratio of alkali metal to phosphorus of 1 to 3.5 to form at least the mono alkali metal phosphate. The solvent is given a water wash to recover entrained alkali metal phosphates. The resulting aqueous solution aforesaid and wash liquor containing the alkali metal salts are separated from the stripped solvent.

Abstract: A method of recovering alkaline chemicals from a material containing sodium or potassium compounds. The material is gasified by an external heat source after which the gas is rapidly cooled by arranging it to contact with cooled solid particles separated from the gas.

Abstract: In flue gas desulfurization, sorbent promoters are recovered by mixing collected particulates with water to form a slurry. The slurry is dewatered and wet solids are disposed. The recovered material contains water soluble desulfurization promoters and is reinjected in a flue gas desulfurization humidification system. The recycle allows recovery of water soluble promoters and reduces consumption. In addition, for promoters having undesirable disposal characteristics, the system improves the disposal characteristics of the waste solids.

Abstract: This invention relates to an apparatus and method for simultaneously scrubbing acidic exhaust gases and removing metal salts from alkaline waste dust from a cement plant or the like thereby producing useful products from what would otherwise be wasted. In essence the two wastes are combined in water and the resulting solution and precipitate separated in a tank. The solution is useful both to cool incoming waste gas and as a fertilizer, whilst the precipitate is suitable as kiln feed stock.

Abstract: Method and system for scrubbing exhaust gas stream from a wet process cement plant wherein a supply of alkaline water and a supply of compressed air are delivered to spray nozzles which are located within the existing exhaust stream ducting. The alkali water is sprayed as a finely divided mist into the duct where it rapidly reacts with the oxides of sulfur and nitrogen present in the exhaust gas. The water, being in the form of very small droplets, and having small volume and large surface area to water volume ratio, rapidly evaporates. The water, therefore, does not cause a problem of wetting and clogging of the ducting and the oxides of sulfur and nitrogen are converted to dry solid particulates which are removed by normal dust collection systems downstream of the scrubber.

Abstract: A process for production of alkali metal phosphates from material containing calcium, iron and aluminium phosphates, for example naturally occurring phosphate rocks, involves calcining the material with alkali metal carbonates to produce alkali metal phosphates, which are then leached from the calcined product under conditions that yield relatively concentrated solutions.

Abstract: Lithium metal is separated from lithium salts in spent torpedo boiler fuel by solubilizing said salts in a solution of a Lewis acid such as boron trifluoride in a polar solvent such as 1,2-dimethoxyethane followed by subsequent separation of the constituents of said mixture.

Abstract: A method is disclosed of producing a liquid agent for improving the quality of contaminated water, particularly water in pools, natural bodies of water and waste waters, characterized by introducing with agitation comminuted rock-salt clay or a mixture thereof with rock-salt deads into an aqueous solution or suspension of an inorganic base, stirring the resultant mixture for 2 to 5 (preferably 3) hours, thereupon adjusting the pH of the resultant solution to a value of between 7.5 and 10.5 (and preferably between 9.5 and 10.5) by means of the addition of acid or alkali, and removing undissolved portions from the solution.

Abstract: In a coal gasification operation or similar conversion process carried out in the presence of an alkali metal-containing catalyst wherein particles containing alkali metal residues are produced, alkali metal constituents are recovered from the particles by treating them with electromagnetic radiation having a frequency between about 0.10 MHz and about 10.sup.5 MHz in the presence of water or other aqueous medium. During the treatment step, the electromagnetic radiation facilitates the extraction of alkali metal constituents from the water-insoluble alkali metal compounds comprising the alkali metal residues. The resultant aqueous solution enriched in water-soluble alkali metal constituents is then separated from the particles depleted in alkali metal constituents and recycled to the gasification process where the alkali metal constituents serve as at least a portion of the alkali metal constituents which comprise the alkali metal-containing catalyst.

Abstract: Metals are extracted from mixtures of oxides or silicates by reacting the mixture at elevated temperature with a gaseous chlorinating agent comprising a mixture of water vapor and hydrogen chloride to selectively chlorinate the desired metal or metals.

Abstract: In the treating of waste slags produced in the desulfurization and/or dephosphorization of molten pig iron with alkali carbonates, the alkali is recovered by extracting said waste slags with hot water while feeding carbon dioxide gas to form an extraction solution having a pH of 9.0-11.5 and recovering alkali carbonates from said extraction solution. The extraction solution contains little sulphur and silicates, from which alkali carbonates can be easily recovered with high yield therefrom.

Abstract: In a coal gasification operation or similar conversion process carried out in the presence of an alkali metal-containing catalyst wherein solid particles containing alkali metal residues are produced in the gasifier or similar reaction zone, alkali metal constitutents are recovered from the particles by withdrawing and passing the particles from the reaction zone to an alkali metal recovery zone in the substantial absence of molecular oxygen and treating the particles in the recovery zone with water or an aqueous solution in the substantial absence of molecular oxygen. The solution formed by treating the particles in the recovery zone will contain water-soluble alkali metal constituents and is recycled to the conversion process where the alkali metal constituents serve as at least a portion of the alkali metal constituents which comprise the alkali metal-containing catalyst.

Abstract: A method for dissolving calcined trona containing calcareous impurities, to obtain an aqueous sodium carbonate solution having low calcium content involves contacting calcined trona in countercurrent flow, desirably under specific temperature conditions, with dilute sodium carbonate solution. Sodium carbonate solutions thus obtained have reduced tendency to form calcium deposits in processing equipment.

Abstract: Mercury and caustic values are recovered from caustic sludges in a process which comprises intermixing the caustic sludge with a liquid under pressure or agitation to produce a caustic slurry which is separated into a caustic liquor, metallic mercury and a remaining sludge which is suitable for roasting in a retort to recover better than 99 percent of the mercury in the sludge.The process recovers valuable mercury and caustic materials and eliminates pollution of natural resources which was formerly caused when these sludges were disposed of in landfill operations. In addition, the process reduces potential hazards to personnel handling the caustic sludges and requires no addition of chemicals which produce undesirable by-products and add to the cost of the recovery process.

Abstract: The invention relates to a novel process for the selective recovery of the sodium content of red mud originating from alumina plants. According to the process of the invention red mud or a slurry thereof is admixed with a ferric sulfate solution, the resulting suspension is stirred intensively for 0.5 to 1 hour at 15 to 85.degree. C, thereafter, if necessary, the pH of the suspension is adjusted to 4.4 to 4.6 and the solid substance is removed from the suspension.Using the process of the invention the sodium oxide content of red mud can be reduced to below 1.5%.

Abstract: This disclosure relates to a process for selectively removing and recovering potassium nitrate in a relatively pure state from tobacco, and especially from Burley tobacco stems. The process comprises the steps of (1) contacting tobacco plant parts with water to obtain an aqueous extract and a fibrous tobacco residue, (2) concentrating the extract, (3) cooling the extract, and (4) separating and recovering the potassium nitrate crystals formed therein. The denitrated aqueous extract is recombined with the fibrous tobacco residue as in making reconstituted tobacco and the like. The purified potassium nitrate is suitable without further purification to use as a fertilizer, thus eliminating costly disposal problems.

Abstract: An apparatus and method for performing a continuous thermal treatment of organic carbonaceous materials under controlled pressure in which the feed material is introduced into the system in the form of a slurry, and the level of liquid is maintained at a preselected operating level, serving as a gas-tight seal. The feed material is conveyed upwardly of the liquid operating level and is thereafter introduced into a reaction chamber in which it is heated to within a controlled elevated temperature range under controlled pressure in a manner to effect vaporization of at least a portion of the volatile substances therein, forming a gaseous phase composed of condensible and noncondensible vapors.

Abstract: The red mud by-product of the Bayer process by which aluminum oxide is reed from bauxite as an aluminate, is digested with concentrated sulfuric acid or with sulfur trioxide gas to produce sulfates that can be leached out to the resulting mass with water. The solution is then heated at a pH of 1 to precipitate titanium oxide hydrate by hydrolysis. The remaining sulfates of the solution are then obtained in solid form by evaporation, or by precipitation with acetone, and the solid is then roasted to convert the aluminum and iron to the oxide. After leaching out the sodium sulfate with water, the aluminum and iron oxide are separated by the Bayer process, which works in this case even though x-ray diffusion patterns show that the aluminum oxide is mainly .alpha.Al.sub.2 O.sub.3.

Abstract: This invention relates to an apparatus and method for simultaneously scrubbing acidic exhaust gases and removing metal salts from alkaline waste dust from a cement plant or the like thereby producing useful products from what would otherwise be wasted. In essence the two wastes are combined in water and the resulting solution and precipitate separated in a tank. The solution is useful both to cool incoming waste gas and as a fertilizer, whilst the precipitate is suitable as kiln feed stock.