Abstract: A system for recovering rare earth elements from coal ash includes a leaching reactor, an ash dryer downstream of the leaching reactor, and a roaster downstream of the ash dryer that is cooperatively connected to both the leaching reactor and the ash dryer. Coal ash is mixed with an acid stream such that rare earth elements present in the coal ash are dissolved in the acid stream, thereby creating (i) a leachate containing the rare earth elements and (ii) leached ash. The leachate is heated to obtain acid vapor and an acid-soluble rare earth concentrate. Mixing of the coal ash with the acid stream can occur in a leaching reactor and heating of the leachate can occur in a roaster. The acid-soluble rare earth concentrate can be fed to a hydrometallurgical process to separate and purify the rare earth elements.

Abstract: The invention provides a process for preparing a C3-7 (hydro)fluoroalkene comprising dehydrohalogenating a C3-7 hydro(halo)fluoroalkane in the presence of a catalyst comprising a metal oxide supported on alumina, wherein the catalyst has a sodium content of less than about 800 ppm.

Abstract: Method for the production of a CO2 sorbent prepared by integrating a clay substrate, basic alkali salt, amine liquid, hydraulic binder, and a liquid binder. The basic alkali salt is present relative to the clay substrate in a weight ratio of from about 1 part to about 50 parts per 100 parts of the clay substrate. The amine liquid is present relative to a clay-alkali combination in a weight ratio of from about 1 part to about 10 parts per 10 parts of the clay-alkali combination. The clay substrate and basic alkali salt may be combined in a solid-solid heterogeneous mixture and followed by introduction of the amine liquid. Alternatively, an alkaline solution may be blended with the amine solution prior to contacting the clay substrate. The clay-alkali-amine CO2 sorbent is particularly advantageous for low temperature CO2 removal cycles in a gas stream having a CO2 concentration less than around 2000 ppm and an oxygen concentration around 21%, such as air.

Abstract: Methods, and related products and compositions, of increasing the stability of a Bayer process liquor are described. A method of increasing the stability of a Bayer process liquor includes contacting the Bayer process liquor with a ppm quantity of a low molecular weight dextran. Also described are methods, and related products and compositions, for controlling the precipitation of aluminum-containing compounds from a Bayer process liquor.

Abstract: The present invention refers to a method being easy to recover metals including nickel and aluminum from waste aluminum catalysts, thereby entirely promoting the recovering rate. Said method comprises: preparing and roasting a waste aluminum catalyst with sodium salts, and then obtaining a first solution comprising vanadium and molybdenum, and a dreg comprising nickel and aluminum through leaching and filtrating; collecting and mixing the dreg with alkali powders to obtain a mixture of the dreg and alkali powders, roasting the mixture at 300 to 1000° C. with aluminum in the dreg reacting with hydroxyl generated from the roasting of mixture and further generating aluminum hydroxide, and then obtaining a second solution comprising aluminum and a concentrate having nickel through another leaching and filtrating; and recovering aluminum from the second solution and recovering nickel from the concentrate.

Abstract: There is provided a hydrometallurgical process of recovering indium and gallium values from mixtures thereof with other metal values for example recycled and scrap solar panel cells which comprises subjecting the mixture to strongly oxidizing acid conditions, preferably via the simultaneous addition of sulfuric acid and hydrogen peroxide to the leach vessel, so as to form indium and gallium salt species of at least the major proportion of the indium and gallium values in the mixture, extracting the indium and gallium values with an organic extractant by adjusting the pH so as to extract individually the indium and gallium values with the organic extractant, stripping indium and gallium values from the extractant using an acid and an alkaline solution respectively and recovering the indium and gallium values.

Abstract: Methods and compositions are described for preparing metal salts and selectively separating metals from substrates and other metals. The methods can include a thionyl reagent that reacts with a metal in a solution to produce a metal salt. The reaction can be controlled by varying reagents and conditions such that the method can be used to selectively separate one or more metals from another metal or from a substrate. The method can also be used for removing metals from a surface. Compositions produced by the method are also described.

Abstract: A method for recovering a metal, capable of recovering a metal easily without requiring the use of an organic medium, is provided. A complex between a chelating agent and a metal present in a sample is formed in a mixture prepared by mixing the chelating agent and the sample under pH conditions where the chelating agent can be insoluble in an aqueous medium. Then, the complex is recovered from the mixture, and further, the metal is recovered by dissolving the recovered complex in an aqueous medium under pH conditions that are different from the pH conditions where the chelating agent can be insoluble in an aqueous medium. By this method, a metal can be recovered easily without requiring the use of the use of an organic medium.

Abstract: The present invention relates to a process for recycling SPL from primary aluminum production, comprising the steps of grinding the separated fractions or cuts, separating materials by means of mechanical treatment, mixing salt slags with SPL, dissolving in water the product obtained in the previous step, carrying out a chemical reaction between water and the materials to be made inert, sedimenting, removing cyanides, filtering to obtain a soluble fraction and another insoluble fraction, washing the insoluble fraction, crystallizing salts of the soluble fraction and aging or conditioning the insoluble fraction. The present invention further relates to the product obtained by means of said process and the use thereof in different fields of the art.

Abstract: A method of producing calcium carbonate from a waste sludge containing calcium carbonate and at least one silicate mineral. The method comprises the steps of: (i) incinerating the sludge to an ash in which at least 60% of the calcium carbonate present in the sludge is converted to free calcium oxide which is unreacted with the silicate mineral(s), (ii) optionally slaking the ash to convert at least a portion of the free calcium oxide therein to calcium hydroxide, (iii) treating either the ash from step (i) or the slaked ash from step (ii) with an aqueous solution of a polyhydroxy compound to provide a solution of dissolved calcium hydroxide, (iv) separating insoluble material from the solution of calcium ions obtained in step (iii), (v) dispersing carbon dioxide through the solution obtained from step (iv) so as to produce calcium carbonate, and (vi) separating the calcium carbonate produced in step (v).

Abstract: A method for recovering base metal values from oxide ore is provided, where the ore includes a first group metal selected from nickel, cobalt and copper. The method includes reducing ore particle size to suit the latter unit operation, favoring contact for the metal elements, contacting the ore with ferric or ferrous chloride, hydrated or anhydrous, to produce a mix of ore and iron (II or III) chloride subjecting the mixture of the ore and ferric or ferrous chloride to enough energy to decompose the chlorides into hydrochloric acid and a iron oxides from the second group, forming their respective chlorides, selectively dissolve the produced base metal chlorides, leaving the metal as oxides and in the solid state, and recovering the dissolved base metal values from aqueous solution.

Abstract: A method of purifying an aluminum source includes dissolving an aluminum ion source to provide a first solution including aluminum ions having a pH of not greater than 4.0, adjusting the pH of the first solution with a tetraalkylammonium hydroxide solution to a pH in range of 4.1 to 8.4 thereby forming an aluminum hydroxide precipitate, separating the aluminum hydroxide precipitate from the first solution, washing the separated aluminum hydroxide precipitate with an aqueous solution having a pH in a range of 4.1 to 8.4, dissolving the washed aluminum hydroxide precipitate using an acid to provide a second solution having a pH of not greater than 4.0, and forming an aluminum salt from the second solution.

Abstract: The invention relates to a method for hydrolyzing hydrolyzable solid metallic salts, wherein the metallic salts are reacted with aqueous saline solutions.

Abstract: Devices, systems, and methods relating to advanced, high pressure oxidation are described. The devices, systems, and methods can be used to decontaminate ground water in a well or opening in a ground water table, and to recover minerals and hydrocarbons from subterranean deposits.

Abstract: A process for recovery of silica and alumina from fly ash, in which, Si is leached out from the fly ash in the form of Na2SiO3 using a NaOH solution of NaOH >40% (w/w), followed by separation to obtain a Na2SiO3 solution and a residue having Al—Si ratio ?2; vaporizing the solution to obtain Na2SiO3 solutions of various concentrations, or producing silica by carbonation, and producing Al2O3 by prior art methods from residues obtained after alkali-leaching, ultimately producing filler or cement from the residue after the recovery of Al. The method permits recovery of Al2O3 directly from fly ash by removing Si before recovering the Al, which raises the Al—Si ratio of the residue after alkali-leaching and thus simplifies the recovery of Al2O3 and raises the rate of Al recovery from fly ash. The invention further includes calcining high Al coal gangue, kaolinite and middle-low-class bauxite at 900-1100° C.

Abstract: A process for producing metal compounds directly from underground mineral deposits including the steps of forming a borehole at a site into a mineral deposit containing metal compounds, inserting a slurry-forming device having a nozzle into the borehole adapted to direct pressurized water through the nozzle into the mineral deposit, supplying pressured water through the nozzle into the mineral deposit forming a mineral slurry containing metal compounds, extracting the mineral slurry containing metal compounds through the borehole, leaching the mineral slurry to convert the metal compounds to a soluble form in a leach solution, and removing metals and metal compounds by treating the leach solution with an extraction treatment adapted to remove the metal products. Steps of leaching the mineral slurry and removing metal products are performed at a location remote from the borehole site. Alternatively, the step of removing metal products from mineral slurry may be accomplished by pyrometallurgical processes.

Abstract: A process for recovery of silica and alumina from fly ash, in which, Si is leached out from the fly ash in the form of Na2SiO3 using a NaOH solution of NaOH >40% (w/w), followed by separation to obtain a Na2SiO3 solution and a residue having Al—Si ratio ?2; vaporizing the solution to obtain Na2SiO3 solutions of various concentrations, or producing silica by carbonation, and producing Al2O3 by prior art methods from residues obtained after alkali-leaching, ultimately producing filler or cement from the residue after the recovery of Al. The method permits recovery of Al2O3 directly from fly ash by removing Si before recovering the Al, which raises the Al—Si ratio of the residue after alkali-leaching and thus simplifies the recovery of Al2O3 and raises the rate of Al recovery from fly ash. The invention further includes calcining high Al coal gangue, kaolinite and middle-low-class bauxite at 900-1100° C.

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: It is an object to provide a method for producing stable alkaline metal oxide sols having a uniform particle size distribution. The method comprises the steps of: heating a metal compound at a temperature of 60° C. to 110° C. in an aqueous medium that contains a carbonate of quaternary ammonium; and carrying out hydrothermal processing at a temperature of 110° C. to 250° C. The carbonate of quaternary ammonium is (NR4)2CO3 or NR4HCO3 in which R represents a hydrocarbon group, or a mixture thereof. The metal compound is one, or two or more metal compounds selected from a group of compounds based on a metal having a valence that is bivalent, trivalent, or tetravalent.

Abstract: A method for treating a polymetallic sulfide ore containing gold and/or silver, and further containing base metals selected from the group consisting of iron, aluminum, chromium, titanium, copper, zinc, lead, nickel, cobalt, mercury, tin, and mixtures thereof, is disclosed. The method comprises the steps of grinding the polymetallic sulfide ore to produce granules, oxidizing the granules to produce oxidized granules, and chloride leaching the granules using a brine solution including dissolved halogens, as well as chloride and bromide salts.

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: A method for the production of inorganic aluminum substances and amorphous silica from aluminum oxide containing ores, comprising: (a) leaching of said ores with fluorosilicic acid to obtain aluminum fluosilicate solution; (b) filtering said leached solution from insoluble materials; and (c) washing said insoluble materials.

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 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: Disclosed is the recycling of aluminum dross. Aluminum dross is crushed into particles which are size-classified on the basis of 1 mm. The aluminum dross particles equal to or smaller than 1 mm in size are leached with an aqueous sodium hydroxide solution to give a leachate which contains sodium aluminate as a result of the reaction the aluminum metal of the aluminum dross particles with sodium hydroxide. The aluminum dross particles greater than 1 mm in size are remelted to recover aluminum metal. In the leachate, a small quantity of aluminum hydroxide is seeded, followed by hydrolyzing the sodium aluminate to obtain aluminum hydroxide. Meanwhile, the leachate is filtered to obtain a residue. This residue is subjected to washing, drying and roasting. The mixing of the roasted residue with aggregate and alumina cement gives alumina castable refractories.

Abstract: The invention relates to a process for recovering the transition metal component of catalysts used in the hydroconversion of heavy hydrocarbonaceous materials. In accordance with the invention, a slurry of a transition metal catalyst and hydrocarbon is catalytically desulfurized resulting in a desulfurized product and a solid residue containing the transition metal. The transition metal may be recovered by coking the residue and then dividing the coker residue into two portions are combusted with the flue dust from the first combustion zone being conducted to the second combustion zone. The flue dust from the second combustion zone is treated with ammonia and ammonium carbonate in order to obtain ammonium molybdate.

Abstract: Processes for improving solids/liquids separation efficiency in the Bayer process are disclosed, wherein solids are flocculated with hydroxamated polymers and centrifuged.

Abstract: The present invention relates to a process for reducing and/or removing inorganic matter from a material containing inorganic matter which comprises the steps of:(i) (a) treating the material with a source of hydrogen fluoride so as to form a first residue and a first solution containing inorganic matter;(b) separating the first residue from the first solution containing the inorganic matter;(c) treating the first residue with an acid so as to form a second residue and a second solution containing further inorganic matter; and(d) separating the second residue from the second solution containing the further inorganic matter; or(ii) (a) treating the material with an acid so as to form a first residue and a first solution containing inorganic matter;(b) separating the first residue from the first solution containing the inorganic matter;(c) treating the first residue with a source of hydrogen fluoride so as to form a second residue and a second solution containing further inorganic matter; and(d) separating the

Abstract: The present invention relates to a process for the preparation of solutions of aluminum salts, characterized in that an aluminate of an alkali metal and/or alkaline earth metal is dissolved in an acid solution to the formation of a solution which is used as such or is diluted to a suitable concentration.

Abstract: Liquid gallium or gallium alloy is utilized as a mercury substitute for a variety of applications. The liquid gallium or gallium alloy is either free of metal oxides or has only very low quantities of metal oxides.

Abstract: A process for treatment of a solid material containing fluoride and sodium, such as spent potlining from aluminum reduction cells, comprising the following steps: 1) contacting the solid material with recycled caustic liquor and source of calcium in a digestor; 2) passing the mixture to a separating device to separate into liquid and solid fraction; 3) recycling part of the liquid fraction containing caustic concentration of 75-200 g/l, calculated as Na.sub.2 CO.sub.3 to step (1); and 4) recovering concentrated caustic liquor from liquid fraction. The product of the process is a solid residue having low levels of leachable fluoride and a concentrated caustic liquor.

Abstract: A method of treating spent potliner material from aluminum reduction cells is disclosed. The spent potliner material is introduced into a sulfuric acid digester to produce a gas component including hydrogen fluoride and hydrogen cyanide and a slurry component including carbon, silica, alumina, sodium sulfate, iron, calcium and magnesium. The gas component is recovered and heated an effective amount to eliminate hydrogen cyanide and produce a remaining gas component including CO.sub.2, H.sub.2 O, nitrogen oxides and HF. The remaining gas component is directed through a water scrubber to form hydrofluoric acid, and the hydrofluoric acid is admixed with aluminum hydroxide to create aluminum fluoride. The slurry component is rinsed with water to separate a first solid fraction containing carbon, alumina and silica from a second liquid faction. The pH of the liquid fraction is adjusted to first create and separate aluminum hydroxide and then to separate sodium sulfate.

Abstract: Processes for reducing the level of impurities in alumina trihydrate produced in the Bayer process are disclosed, wherein alumina trihydrate-containing process streams are flocculated with hydroxamated polymers and centrifuged.

Abstract: Improved process for fluidifying flocculated aqueous suspensions of red muds in the production of alumina from bauxite by the Bayer process, which consists:in dissolving bauxite using sodium hydroxide;then, in decanting and in washing the red muds formed in order to separate them from the alumina in successive vats, while recycling the washing waters upstream;and finally, in eliminating the red muds thus treated;and in which a flocculant (F) consisting of a polyacrylamide of molecular weight greater than ten million is introduced into the suspension of one of the successive vats;wherein a dispersing agent (D) formed by an anionic acrylic acid polymer of molecular weight lower than fifty thousand is added simultaneously with said flocculant (F) to the suspension in the same vat.

Abstract: Aluminum and fluorine are recovered from fluorine containing waste materials from the production of aluminum metal (FCWM) as ALF.sub.2 OH hydrate by a process comprising: leaching FCWM with dilute sulphuric acid at a pH value within the range of 0-3; if needed adding aluminum in an acid soluble form; adjusting the pH value of the aqueous phase to a value within the range 3.7-4.1 at the end of the leaching period by addition of a caustic aqueous solution; precipitating silica at a temperature not exceeding 60.degree. C.; separating the reaction mixture into a solid phase containing precipitated silica and non-soluble residues of the FCWM and a purified solution; and precipitating AlF.sub.2 OH hydrate from the purified solution at a temperature within the range 90.degree.-100.degree. C. and at a pH value not exceeding about 4.1 by controlled continuous addition of an aqueous caustic solution. Reducing and/or non-oxidizing operating conditions are maintained during all these process steps. The precipitated AlF.

Abstract: A process for recycling spent potlining material from aluminum reduction cells contaminated with fluoride and aluminum values. The process comprises first reducing the average particle size of the spent potlining material to smaller than 28 Tyler mesh to form a powder. The powder is then treated with an aqueous sodium hydroxide solution containing about 10 to 60 g/L of sodium hydroxide at a temperature in the range of between 60.degree. and 90.degree. C. to form a solution containing fluoride and sodium aluminate and a residual solid. The solution is removed from the residual solid and the content of NaOH is adjusted in the solution to the range of about 10 to 60 g/L of NaOH, if the content differs from this range, to produce a solution suitable for cyanide destruction. This solution is then heated to a temperature in the range of about 160.degree. to 220.degree. C. at a pressure in the range of about 150 to 350 p.s.i. for a time of between about 1/2 and 3 hours to destroy cyanide values in the solution.

Abstract: A method for inhibiting the precipitation of sodium oxalate crystals in a Bayer process liquor. The method comprises the step of adding to the Bayer process liquor, after red mud separation and immediately prior to crystallization of alumina trihydrate, or during crystallization of alumina trihydrate, or during classification of alumina trihydrate, an effective amount of a cationic, surface active, alkylammonium salt compound.

Abstract: A mercury-free dissolution process for aluminum involves placing the aluminum in a dissolver vessel in contact with nitric acid-fluoboric acid mixture at an elevated temperature. By maintaining a continuous flow of the acid mixture through the dissolver vessel, an effluent containing aluminum nitrate, nitric acid, fluoboric acid and other dissolved components are removed.

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: Gallium is efficiently extracted from strongly basic solutions containing aluminates by extractants having the tris- and/or tetrakis(2-hydroxybenzyl)-1,2-diaminoethane chemical moiety. The diaminoethane derivative may be used together with a hydrocarbyl 8-hydroxyquinoline and/or with a tertiary carboxylic acid.

Abstract: A method for the continuous treatment of air pollution control residues from various resource recovery systems whereby the air pollution control residue is treated with a dilute salt extracting solution at a pH chosen to maximize the recovery of lead, for a reaction time chosen to maximize the recovery of lead, and for a number of recycles chosen to maximize the recovery of lead from the particular residue being treated. Other metals and dissolved salts can also be recovered from the extracting solution. Thus by monitoring these three variables for each batch of residue, and adjusting the extracting solution accordingly, residue from various sources and of varying composition can be treated efficiently and continuously to remove hazardous metals and dissolved salts from the residue. Bottom residue fines, alone or admixed with air pollution control residues, can also be treated in accordance with the process of the invention.

Abstract: A process for the treatment of spent pot linings impregnated with alkali metal cyanide and fluoric products by grinding previously crushed pot linings in the presence of lime, suspending the ground pot linings in an aqueous medium in order to precipitate a flux in the form of CaF.sub.2 accompanied by the release of soda, followed by the heating of the suspension at a temperature T>140.degree. C. in the presence of clay to form, after fixing the free soda, insoluble synthetic silicate compounds of the feldspathoid or zeolite type and finally the separation by filtration of the resulting solid phase from the liquid phase, which liquid phase is recycled to form a new ground pot lining suspension.

Abstract: A process for hydrofluoric acid digestion of inorganic silica/alumina matrix material for the production of silicon tetrafluoride and aluminum fluoride comprises the initial step of reacting the matrix material with hydrofluoric acid, to form silicon tetrafluoride gas and a solution/slurry containing aluminum fluoride, undigested oxides, and additional soluble and insoluble fluoride materials. The silicon tetrafluoride gas is purified of contaminants by condensing out impurities in cold traps and reacted with aqueous sodium fluoride to form a solution/slurry of fluorosilicate salt which is delivered to a filter press to separate sodium fluorosilicate powder from the solution/slurry. The sodium fluorosilicate powder is dried and delivered to a kiln at a temperature of about 600.degree. C. to 650.degree. C. to form substantially pure silicon tetrafluoride gas and sodium fluoride powder for collection.

Abstract: A process is disclosed for treating salt-containing aluminum dross to remove potassium and sodium chloride salts therefrom. The process generally comprises treating the dross in a first treating step with a leaching solution having a pH maintained in the range of about 6-7 to remove a portion of the salt content thereof; filtering the residual solids from the first leaching solution; and treating the filtered solids in a second treating step with a second leaching solution having a pH maintained above about 8, and preferably above about 9. The pH of the first leaching solution is maintained in the desired range by the addition of hydrochloric acid, and the pH of the second leaching solution is maintained in the desired range by the addition of potassium and/or sodium hydroxide.

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: Gallium values are recovered from basic aqueous solutions thereof, e.g., Bayer liquors, by (i) contacting such basic aqueous solution (A) with a medium (I) containing a gallium extractant, whereby the gallium values are transferred to the medium (I), (ii) contacting such gallium-enriched medium (I) with a basic aqueous solution (B) and back-extracting the gallium values into the basic aqueous solution (B), (iii) contacting such gallium-enriched basic aqueous solution (B) with a second medium (II) containing a gallium extractant, whereby the gallium values are transferred to the medium (II), and (iv) contacting such gallium-enriched medium (II) with an aqueous solution (C), which may be acidic or basic, and back-extracting the gallium values into the aqueous solution (C); such gallium-enriched aqueous solution (C) may, for example, be directly electrolyzed to produce gallium metal.

Abstract: A process for the recovery of metallic aluminum, mixtures of salts, and an aluminum oxide-metallic aluminum product from secondary aluminum dross. The process includes treating the dross with leach water to dissolve the salt content. Magnesium chloride is preferably added to the leach water to maintain the pH in the range of about 7-8.5, thereby reducing ammonia production in the treating step and enhancing recovery of metallic aluminum.

Abstract: Tall oily fatty acids when combined with certain non-ionic surfactants having an HLB number from 10-14 are superior dewatering agents for Bayer Process alumina trihydrate filter cakes.

Abstract: A process is disclosed for producing high brightness kaolin from ore containing silica, other types of clays, minerals such as ilmenite micas, feldspars and various metal silicates as well as organic matter. The process consists of sizing, a double floatation step, magnetic separation, leaching and oxidative brightening steps. This is a novel combination of conventional unit operations and in particular the use of a double floatation step to remove quartz and various trace minerals that interfere with achieving high optical brightness for kaolin.

Abstract: A process is described for removing dissolved silica from process solutions or slurries formed in the Bayer process for producing alumina from bauxite. In the novel process, a Bayer process solution or slurry is contacted with porous agglomerates of a material containing Bayer process desilication product and bonded together by a polymer resin which is resistant to chemical degradation by high concentrations of caustic present in Bayer process liquors. The desilication product is essentially complex hydrated sodium aluminum silicates and typical bonding resins are polyvinylchloride or polypropylene.