Abstract: A method is provided of producing a self-supporting ceramic composite structure having one or more encasement members, such as an encasing steel sleeve, joined to it by growth of the ceramic material to engagement surface(s) of the encasement member(s). A parent metal is contacted with a body of filler which is encased by the encasement member(s). The resulting assembly is heated to melt and oxidize the parent metal, e.g., aluminum, to form a polycrystalline material comprising an oxidation reaction product which grows through the doby of filler and stops at the engagement surface(s) of the encasement member(s) which thereby determines the surface geometry of the grown ceramic matrix. Upon cooling, the encasement member(s) is shrink-fitted about the ceramic composite body. The invention also provides the resultant articles, for example, a ceramic composite body having a stainless steel member affixed thereto.

Abstract: A product suitable as a ceramic comprises substantially nonaggregated alumina particles with 95% by number having an aspect ratio (i.e., the ratio of the longest dimension to the shortest dimension for any single particle) not greater than 1.1 and more than 80% having an aspect ratio not greater than 1.05 and having a geometric mean size of from 0.02 to 0.5 microns. Usually the product contains no more than 3% by weight as aggregates and preferably the product is as small as can conveniently be manufactured.

Abstract: A method for purifying starting materials for chalcogenide glass is disclosed, which comprises contacting chalcogen starting materials at a high temperature with a metal which is more susceptible to oxidation than the chalcogen starting materials to allow the metal to react with oxygen contained as impurity in the chalcogen starting material to form an oxide of the metal, and then removing the metal and the oxide of the metal from the chalcogen starting materials.

Abstract: In a process utilizing steam, the method of producing at least a portion of said steam, including heating a water-containing, solid substance for generating steam and capturing the generated steam for said process. A suitable solid substance is Al(OH).sub.3. New alumina products are obtained.

Abstract: Gallium is recovered from gallium arsenide by reacting and dissolving the gallium arsenide with an oxidant and a complexing agent, especially with water insoluble hydroxamic acids with mild conditions, e.g. with aqueous hydrogen peroxide and mild temperature, to effect separation of gallium hydroxamic acid chelates from water soluble arsenic compounds.

Abstract: A process for treating solid substantially non-volatile wastes contaminated with a heat sensitive contaminant is disclosed. The wastes are heated to form a liquid slag. The liquid slag is held at elevated temperature until at least a portion of the contaminating components have either decomposed or evolved from the melt as a gas. The slag is subjected to cooling and the contaminating compounds are bound or encapsulated into a solid glassy slag. The process is particularly suitable for handling fluoride and cyanide contaminated aluminum smelting wastes such as spent potliner material. It is advantageous to add silica to such wastes. The residue from the slagging reaction is a glassy solid sodium metal silicate matrix such that the fluoride residues remaining in the wastes are encapsulated. The amount of silicate blended with the feed material is selected to substantially tie up all of the sodium remaining in the residue after slag melting and is typically 7.5 to 50 weight percent of the feed.

Abstract: 5 to 50 wt. % of an alkaline flux such as sodium carbonate, sodium hydroxide, potassium carbonate and potassium hydroxide is added and mixed to aluminum smelting dust. The mixture is roasted, the roasted mixture is acid-leached with mineral acids such as sulfuric acid, hydrochloric acid and nitric acid, and then gallium is preferentially extracted at a high yield compared to other components of the dust.

Abstract: A process for producing alumina involving reacting anhydrous aluminum chloride with a oxidizing agent with a temperature within the range of from about 700.degree. C. to about 1200.degree. C. to form aluminum oxide and chlorine and separating the chlorine and mixing a portion thereof with the reacting aluminum chloride and oxidizing agent.

Abstract: Hazardous waste containing inorganic compounds which contain heavy metals or particular hazardous anionic groups or which are hazardous halides or non-metal oxides or sulfides is contacted with molten aluminum to provide reduction to lower less hazardous oxidation state.

Abstract: A process for the production of high purity silane by reacting silicon tetrafluoride exclusively with sodium aluminum tetrahydride, potassium aluminum tetrahydride, or a mixture of sodium aluminum tetrahydride and potassium aluminum tetrahydride, preferably in an inert liquid reaction medium comprising an ether. The inventive process is a highly advantageous and economical route to silane since it also produces valuable fluoride salt.

Abstract: Metal oxides having a very narrow pore size distribution of micropores within the range of between 10 and 100 Angstroms can be prepared by reacting a water-soluble basic salt of a metal hydrate with an organic compound such as an acid halide in a specific manner. The pore diameter of the metal oxide can be arbitrarily controlled within the range of micropore size by changing the molecular chain length of an organic compound, treating with an acid or calcinating at a different temperature. It is desirable that the narrow pore size distribution is centered within the range of 1.about.30 Angstroms, preferably 1.about.15 Angstroms when the metal oxide is used as a catalyst carrier.

Abstract: A process for treating fluoride-contaminated scrap lining material from electrolytic reduction cells comprises mixing the material with 7-30 parts of sulphuric acid and sufficient water to bring liquid content to 60-80 parts per 100 parts of lining material, mixing in sufficient lime to at least neutralize the sulphuric acid and make the slurry slightly alkaline, the slurry then being allowed to set into a solid mass.The slurry should be of a paste-like consistency. The lime may be wholly calcium hydroxide, but a substantial proportion may be in the form of calcium carbonate.The scrap, before or after the above treatment with lime and sulphuric acid, is preferably heated to 150.degree.-500.degree. C. in the presence of water vapor to destroy cyanides.

Abstract: A process for the beneficiation of an iron-containing material is carried out by first chlorinating the iron-containing material. Oxidation of ferrous chloride in the effluent gas from the chlorination is carried out under controlled conditions of oxygen supply so that more than 50% but less than 100% of the ferrous chloride is oxidized. In this way chlorine gas is separated from the process stream in a relatively pure form which can be utilized in a continuous process by recycle to another chlorination.

Abstract: The invention relates to a process for manufacturing coarse, crystalline alumina which, after preparation in a generally known manner, is suitable for use as grinding, lapping and polishing materials. The process comprises the calcining of alumina from dry absorption scrubbing units employed in connection with fused salt reduction cells producing aluminum.

Abstract: A coating comprising elemental silicon is electrodeposited on a substrate from an aqueous medium. The plating bath is a solution of what is described as one or more metal hydrides. The metal hydrides of the present invention are provided by combining stoichiometric amounts of metal, alkaline metal hydroxide and water in a preselected proportion by mole percent. The particular proportion is a function of the particular metal. A hydride concentrate is provided which is used in aqueous solution to provide a plating bath.

Abstract: The invention relates to a method for recovering useable products from waste products deriving from the manufacture of aluminium fluoride on the basis of aluminium hydroxide and fluosilicic acid. Mother liquors and washing water from a scrubber in said process, which solutions contain aluminium, silica, fluorine, and phosphorous is reacted in a first step with sodium ions at pH 2-3, and a temperature of 50.degree.-100.degree. C. to give a precipitate of sodium fluoroaluminate, which is isolated. The filtrate from said first step can be reacted with the silica waste product obtained in the above mentioned aluminium fluoride manufacture.

Abstract: A leaching process employing acidic chloride solutions, whereby the iron content of aluminous materials such as lower grade iron-containing bauxite ores is reduced, enabling the obtention of valuable products such as metallurgical grade alumina and refractory grade bauxite, previously obtainable only from higher grade low-iron aluminous materials.

Abstract: Aluminum dross containing chlorides and combustible volatile material is agglomerated and sized to produce a compact which is then treated in a direct fired rotary kiln in excess of 1800.degree. F. to volatilize the chlorides and burn the combustible volatile material and to produce a refractory material. The flue gases containing the volatilized chlorides are then treated in a condenser where the chlorides are condensed out of the remaining flue gases. The refractory product from the kiln may be passed through a cooler wherein the heat is transferred to the combustion air.

Abstract: Aluminous siliceous starting materials are mixed and ground with correction materials to produce a raw mixture comprising oxides of aluminium, silicon, calcium and alkali metal having certain mole ratios, preheating the raw mixture by suspending the raw mixture in a hot gas, and sintering the preheated material to clinker.

Abstract: During the final stages of Al(OH).sub.3 production, deliquoring the aluminum trihydroxide slurry of excess sodium ions in the form of caustic liquor is conventionally achieved by numerous water washes prior to drying the product. Addition of an effective amount of highly charged, high molecular weight anionic polymer flocculant to the aluminum trihydroxide slurry improves the filtration rate, i.e., increases the amount and rate of removal of caustic liquor from the slurry. Addition of the flocculant reduces the amount of washing necessary to remove sodium ions from the final cake and also provides higher cake solids which results in greater production per unit time and less expenditure of energy in the drying process. Anionic polymers derived from 80 to 100% of an anionic vinyl monomer such as acrylic acid and from 20 to 0% of a nonionic vinyl monomer such as acrylamide having molecular weights between 1.5 to 12.0.times.10.sup.6 are useful in deliquoring aluminum trihydroxide slurries.

Abstract: The low shear, slurry viscosity of a kaolinitic clay that is contaminated with one or more forms of expanding clay is reduced by mixing the clay with a source of cationic potassium and then heating the potassium-treated clay to a temperature of at least about 100.degree. C.

Abstract: A leaching process employing acidic chloride solutions, whereby the iron content of aluminous materials such as lower grade iron-containing bauxite ores is reduced, enabling the obtention of valuable products such as metallurgical grade alumina and refractory grade bauxite, previously obtainable only from higher grade low-iron aluminous materials.

Abstract: A process for recovering non-ferrous metal values from their ores, minerals, concentrates, oxidic roasting products, or slags by sulphating said starting material using a mixture comprising iron (III) sulphate and alkali metal- or ammonium sulphate as a reagent.

Abstract: A method for recovery of fluoride values from spent potlining and fluoride containing insulating materials associated with the potlining is disclosed. Spent potlining and the insulating materials are reduced to a fine particle size and incinerated. The ash residue is leached with a dilute caustic and the leachate is treated with a calcium compound to precipitate calcium fluoride. The calcium fluoride is dried to a moisture content of less than 0.1 percent and is treated with about 93 to 99 percent concentration of sulfuric acid to produce hydrogen fluoride gas and a metal sulfate. The hydrogen fluoride gas is fed into an alumina dry scrubber to produce alumina with absorbed fluorides to be used as feed material to reduction cells used in the manufacture of aluminum by electrolytic reduction. The metal sulfate residue is treated with lime and constitutes an environmentally safe product which can be disposed of as landfill material.

Abstract: A process was developed using hydrogen peroxide for the oxidation of thallium (I) to thallium (III) in a solvent at a pH of 9.0 or less. Any convenient solvent may be used, such as water, acetic acid, methanol, or a mixture of solvents. Optionally, a buffered solvent may be used.

Abstract: A process was developed to optimize the thallium (III) produced by the reaction of hydrogen peroxide and thallium (I). In the optimized process, thallium (III) is removed from the reaction mixture during the oxidation reaction.

Abstract: There is disclosed a method for the treatment of aluminum dross oxides which contain aluminum metal, aluminum carbide, aluminum nitride and salts such as potassium and sodium chloride. The method comprises the thermal treatment of an aqueous suspension of the dross oxides with agitation in the presence of a particulate grinding medium. The method is practiced in a stirred reactor vessel which contains a bed of refractory, ceramic balls that are agitated with a slurry to provide a sufficient abrading action on the aluminum metal particles to remove the aluminum hydroxide coating and continually expose the aluminum metal for reaction with the water. This invention comprises the introduction of a purge gas into the suspension, preferably air, during its thermal treatment to reduce the formation of foam during the treatment and to assist in liberation of ammonia formed by the decomposition of the aluminum nitride.

Abstract: A process for removing sulfur dioxide from effluent gas and for recovering amphoteric components such as alumina from solid inorganic combustion byproducts.

Abstract: A process for converting a thallium (I) compound to a thallium (III) compound comprising contacting an alkaline solution of the thallium (I) compound with gaseous oxygen and in the presence of a peroxygen compound.

Abstract: A process is described whereby the "saw kerf" can be reprocessed in sufficient purity to be re-used in the process, thereby improving the economics of production of GGG wafers significantly. Gadolinium and gallium oxides are recovered and separated from transition metal impurities introduced during fabrication of GGG wafers. The process "saw kerf" produced from slicing the crystal boule is dissolved by refluxing in HNO.sub.3, treated with oxalic acid and the resulting oxalates and nitrates separated. Pyrolysis of these salts at temperatures of at least 850.degree. C. resulted in their conversion to Ga.sub.2 O.sub.3 of purity >99.99%. The process can be extended to include purification and re-use of by-products generated in other grinding and polishing operations which may result in the recycling of the order of 80% of the generated by-products.

Abstract: A process is described whereby the by-products derived from the fabrication of Gd.sub.3 Ga.sub.5 O.sub.12 (GGG) wafers sliced from boules grown from Gd.sub.2 O.sub.3 and Ga.sub.2 O.sub.3 can be reprocessed in sufficient purity to be re-used in the process of growing GGG boules, thereby improving the economics of GGG wafer production. Gadolinium and gallium oxides are recovered and separated from transition metal impurities introduced during fabrication of GGG wafers. The "saw kerf" produced from slicing the crystal boule is dissolved in HCl and filtered to remove residual solids. Gasolinium oxalate is precipitated from the acidic solution by the addition of oxalic acid. Calcination at 850.degree. C. resulted in the isolation of Gd.sub.2 O.sub.3 of >99.99 purity.The pH of the filtrate is adjusted to about 11 with alkali metal hydroxide followed by the addition of sulfide ion. The precipitated transition metal sulfides are removed by filtration. Excess sulfide is removed by treatment with 30% H.sub.2 O.sub.

Abstract: An improvement in the lime-sinter process for recovering alumina from pulverized coal fly ash is disclosed. The addition of from 2 to 10 weight percent carbon and sulfur to the fly ash-calcium carbonate mixture increase alumina recovery at lower sintering temperatures.

Abstract: A high quality iron oxide concentrate, suitable as a feed for blast and electric reduction furnaces is recovered from pulverized coal fly ash. The magnetic portion of the fly ash is separated and treated with a hot strong alkali solution which dissolves most of the silica and alumina in the fly ash, leaving a solid residue and forming a precipitate which is an acid soluble salt of aluminosilicate hydrate. The residue and precipitate are then treated with a strong mineral acid to dissolve the precipitate leaving a solid residue containing at least 90 weight percent iron oxide.

Abstract: Gd.sub.2 O.sub.3 and Ga.sub.2 O.sub.3 are currently used for the fabrication of Gd.sub.3 Ga.sub.5 O.sub.12 (GGG) wafers which are employed as substrates for bubble domain memory devices. In the processing, in the order of 25% of the starting material ends up as process "saw kerf" contaminated with variable amounts of iron, nickel, magnesium, aluminum, zirconium, iridium and silicon. A process is described whereby the "saw kerf" can be reprocessed in sufficient purity to be re-used in the process, thereby improving the economics of production of GGG wafers significantly. Gadolinium and gallium oxides are recovered and separated from transition metal impurities introduced during fabrication of GGG wafers. The process "saw kerf" produced from slicing the crystal boule is dissolved in HCl, treated with H.sub.2 SO.sub.4, and the resulting sulfates separated. Metathesis with (NH.sub.4).sub.2 C.sub.2 O.sub.4 results in conversion of the sulfates to the ammonium oxalates which were calcined at 850.degree. C.

Abstract: Novel sequestering agents useful for the extraction of metal values and in various organic syntheses comprise a cross-linked organic polymeric substrate, said substrate having covalently coupled thereto a plurality of functional groups, the free valence of which having the structural formula: ##STR1## wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.6 and R.sub.7, which are identical or different, each represents a hydrogen atom or an alkyl radical having 1 to 4 carbon atoms, R.sub.5 and R.sub.8, which are also identical or different, each represents a hydrogen atom, an alkyl or cycloalkyl radical having 1 to 12 carbon atoms, a phenyl radical, a --C.sub.g H.sub.2q --.phi. or C.sub.q H.sub.2+1 --.phi.-- radical, and further wherein q ranges from 1 to about 12, and n, m and p, which are also identical or different, range from 1 to 10, and .phi. is phenyl.

Abstract: Cryolite (Na.sub.3 AlF.sub.6) as a source of aluminum is prepared from coal fly ash by reacting the aluminum oxide (Al.sub.2 O.sub.3) in fly ash with phosphoric acid to form aluminum phosphate, which is then converted to sodium aluminate by reaction with sodium hydroxide, and the sodium aluminate is converted to cryolite by reaction with hydrofluoric acid (HF), or equivalent reagent providing H.sup.+ and F.sup.- ions. Aluminum is thereby obtained from fly ash in a preferred form (as cryolite) for use in producing metallic aluminum.

Abstract: A process for settling sedimentary materials wherein aqueous suspensions thereof are treated with H.sub.2 S as a means for separating clays containing metals associated therewith.

Abstract: A method for the recovery of anhydrous aluminium chloride from a mixture of the aluminium chloride with ferrous chloride or ferric chloride, or both, which comprises subjecting the liquid mixture to a reduction in pressure, the conditions being such as to bring about dissociation of compounds of aluminium chloride and ferrous chloride present in the mixture, thereby to form an aluminium chloride-rich vapour and an iron chloride-rich solid and then separately collecting of the iron-and aluminium-rich components under conditions which give the minimum opportunity for recombination.

Abstract: A method for producing aluminum chloride suitable for direct introduction into an aluminum chloride reduction cell by treatment of the gas stream emerging from an aluminum value source chlorination process comprising the steps of:1. reducing and condensing iron chloride in one or more iron chloride condensation stages;2. absorbing the aluminum chloride contained in the gas stream under high temperature conditions with an alkali chloride or alkali chloride mixture to form an ionic alkali chloride-aluminum chloride complex; and3. selectively condensing the chlorides from the product by step (2) to produce a purified aluminum chloride-alkali chloride complex suitable for direct introduction into an aluminum chloride reduction cell.

Abstract: A process for the recovery of substantially all of the aluminum from aluminum bearing waste products which includes a method for the commercial production of alumina and compounds of alumina.

Abstract: Disclosed is a method for obtaining alumina from silicates by calcining a dry mixture of the silicate and an alkali metal or ammonium salt, such as the sulphate, bisulphate, sulphite, etc. and dissolving the reaction product in water or an aqueous alkali. Hydrated alumina is precipitated from the resulting solution and calcined to alumina.

Abstract: A process for the recovery of soluble alumina values from alumina-bearing ores comprising simultaneously contacting a stream containing an effective amount of a reducing agent such as SO.sub.2 and a stream containing an effective amount of an oxidizing agent such as Cl.sub.2 with an aqueous slurry of the alumina-bearing ores for a time sufficient to remove at least about 50 weight percent of the soluble alumina values from said ores is disclosed.

Abstract: A method for the production of reduction cell grade alumina from alkali metal/aluminum chloride complexes comprising the steps of:A. reacting the alkali metal/aluminum chloride complexes with oxygen in a three phase fluidized bed comprising:(I) as a solid phase, particles or pebbles of alumina of at least about 1/16" in average diameter;(II) as a gaseous phase oxygen fed at a rate to provide a fluidizing gas velocity above about 8'/sec.; and(III) as a liquid phase coating the particles of alumina an alkali metal/aluminum chloride complexes; andB. separating the product solids from the gases exiting the fluidized bed.

Abstract: Pure alumina (Al.sub.2 O.sub.3) is recovered from alunite (Al.sub.2 (SO.sub.4).sub.3.K.sub.2 SO.sub.4.4 Al (OH).sub.3) which is found mixed with various impurities by first calcinating the alunite in the presence of a chloride to produce impure Al.sub.2 O.sub.3 and other biproducts, and the impure Al.sub.2 O.sub.3 is then contacted with concentrated HCl to produce, after concentration and crystallization, crystals of AlCl.sub.3.6H.sub.2 O. These crystals are then calcinated to yield highly concentrated HCl and pure alumina.

Abstract: There is disclosed a method for the elimination of the chief impurities in aluminum dross tailings. The method can be used as a pretreatment in the manufacture of aluminum sulfate from aluminum dross tailings in a continuous flow reaction zone in which the dross tailings prior to reaction with sulfuric acid are pretreated to reduce the more objectionable contaminants contained therein to acceptable levels. The most objectionable contaminant in the dross tailings is aluminum metal which, in the invention, is oxidized with water or steam at elevated temperatures. The dross tailings, which are chiefly particles of aluminum oxide, are suspended in an aqueous slurry and the slurry is heated to a temperature from 185.degree.-225.degree. F. and maintained under liquification pressures and sufficient agitation to insure particle-to-particle attrition that removes an aluminum hydroxide coating which would otherwise inhibit the reaction.

Abstract: A method of recovering fluorine, e.g. as hydrogen fluoride, from wastes of aluminum electrolysis furnaces, chemisorbents, adsorbents or absorbents, etc. in which the fluorine-containing material is subjected to pyrohydrolysis in an expanded fluid bed and the HF-containing gas is subjected to condensation or scrubbing for the removal of the HF therefrom. According to the invention, the exhaust gases from the fluidized bed are cooled by direct contact with solids which can be circulated in a separate cycle and are themselves cooled in a cooler, e.g. by contact with gas which is to be fed to the expanded fluidized bed. The circulated solids thus allow recovery of the sensible heat of the gas without diluting it.

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: An improved method of extracting titanium from titaniferous materials by reaction with thionyl chloride to form titanium tetrachloride which is separated from the reaction products by volatilization or by extraction.

Abstract: A process for the treatment of an aluminum-salt slag produced in the remelting of aluminum by the addition of salt to aluminum scrap wherein the aluminum salt slag is subjected to pressure and impact rolling to a thickness of about 0.2 mm to about 1 mm and the product is milled to an X.sub.80 value of about 130 to 150 microns. The milled product is classified in a plurality of stages to recover therefrom a large-particle fraction consisting at least predominantly of aluminum particles, and a fine-particle fraction. The fine-particle fraction is subjected to flotation in at least one flotation stage to which a base is added in an amount of 0.04 to 0.4 g of the base per ton of the material subjected to flotation to bring the pH to between 10 and 11, whereupon a cation active collector of the formula RO--(CH.sub.2).sub.n --NH--(CH.sub.2).sub.n --NH.sub.2 is added to recover an impurity-containing froth of low chloride level and a concentrate containing most of the chlorides of said slag.

Abstract: Inexpensive hydrates of alumina are used for the production of dense, submicron alumina bodies by conversion of the alumina hydrates to a soluble form which is then used to produce a boehmite gel. The boehmite gel, with very small particles of alpha alumina intimately dispersed therein is dried and fired to 1300.degree. C. to 1450.degree. C.