Abstract: Bayer process caustic liquors are purified by treating the liquors with an organic solvent of relatively low boiling point, such as methanol, which causes the precipitation of inorganic carbonate and/or sulfate salt from the treated liquor. The treating solvent can be readily recovered for reuse.

Abstract: Alkali and alkaline earth metal chlorides contained in a residue of a chlorination process of a feed material of bauxite or clay associated with coal are removed by the addition of sulfuric acid which causes their conversion to their sulfate form, and the simultaneous production of hydrochloric acid. The residue, which has been rendered environmentally acceptable, can be disposed of readily, for example, to an ash pond or disposal area for flue gas desulfurization sludges. The hydrochloric acid is then recycled to the chlorination process. The hydrochloric acid may be utilized, for example, as a binder of the feed material, to prechloridize the feed material or as a portion of the leach solution when the chlorination process is a hydrochloric acid leach.

Abstract: New energetic salts NF.sub.4 XeF.sub.7 and (NF.sub.4).sub.2 XeF.sub.8 are prepared by reacting NF.sub.4 HF.sub.2 with XeF.sub.6 and exposing NF.sub.4 XeF.sub.7 to blue 4880.ANG. laser light.

Abstract: In the production of alumina from aluminous ores containing alumina trihydrate and alumina monohydrate comprising a first-stage digestion by digesting alumina trihydrate from a slurry of the ores and a caustic solution and separating the resulting slurry into a caustic aluminate solution and an insoluble residue, and a second-stage digestion by digesting alumina monohydrate from a slurry of the insoluble residue separated in the first-stage digestion and a caustic solution, the present invention provides an improvement wherein scale formation onto a preheater for the slurry in the second-stage digestion is completely or substantially prevented and reduction in heat transfer coefficient of heat transfer surface is remarkably lowered. The improvement is attained by setting up a desilication reaction zone in the course of the first-stage digestion, whereby the slurry introduced into said zone is subjected to desilication reaction treatment.

Abstract: At least a single stage chlorination system for the production of a substantially iron-free alumina-silica product from Bauxites, Bauxitic Clays and Clays wherein at least one chlorination agent is selected from the group consisting of Cl.sub.2, COCl.sub.2, AlCl.sub.2, AlCl, SiCl.sub.4 and SiCl.sub.2 and wherein the said chlorination agent is a limited percentage of the total gas stream.

Abstract: At least a two stage chlorination system for the production of aluminum trichloride and aluminum monochloride wherein in the gas stream containing the highest percentages of aluminum chloride produced CO.sub.2 is present and the said gas stream is passed through a charcoal or devolatilized coke bed in a preferred temperature range of about 1000.degree. C. to 1600.degree. C. to convert the said CO.sub.2 to CO and cycling at least part of the said CO produced to at least the second chlorination stage.

Abstract: At least a single stage chlorination system for the production of a substantially iron-free alumina-silica product from Bauxites, Bauxitic Clays and Clays wherein at least one chlorination agent is selected from the group consisting of Cl.sub.2, HCl and COCl.sub.2 and at least one chlorination agent from the group consisting of AlCl.sub.3 and SiCl.sub.4.

Abstract: Solid solution of niobium or tantalum and a second metal react rapidly with hydrogen under mild conditions, eliminating the need for a high temperature induction process. Suitable second metals include Al, Co, Cr, Fe, Mn, Mo, Ni, Cu, V, Si, Ge and Ga.

Abstract: At least a two-stage chlorination system for the production of a substantially iron-free alumina-silica product from Bauxites and Clays wherein in a preferred embodiment of the invention the chlorination agent is selected from the group consisting of Cl.sub.2, HCl and COCl.sub.2 in the first chlorination stage and wherein in the second chlorination stage the chlorination agent is selected from the group consisting of AlCl.sub.3 and SiCl.sub.4.

Abstract: The method for extraction of precious metals from leachable ores and forming a building materials which includes the steps of crushing a quantity of leachable ore into a powder of substantially uniform particle size, mixing with a quantity of a binding material and mixing with a leaching material. The materials are then formed into a masonry building construction article having at least one passage therein. A plurality of the masonry building construction articles are stacked with at least some of the passages disposed therein in generally parallel flow paths and a solvent is passed through the passages of the masonry building construction articles.

Abstract: Process for extracting molybdenum from aqueous solutions containing alkali metal carbonate, sulphate, hydroxide or hydrogen carbonate and, primarily, one at least of the metals belonging to the group formed by vanadium, uranium and molybdenum, in the form of alkali metal salts, and mineral and/or organic impurities, said solutions resulting from an ore attack cycle and being taken off after extraction of the metal being sought, in the form of a concentrate, wherein said solutions are caustified by the addition of a suitable amount of lime, converting the carbonate present into alkali metal hydroxide, a first precipitate is separated from the alkali metal hydroxide-rich liquor, said liquor is concentrated until the alkali metal hydroxide content is at most equal to 50%, to cause the production of a second precipitate formed by alkali metal sulphate and molybdate, which is solubilized in an aqueous recycle liquor, said re-dissolution liquor then being treated with sulphide ions and then acidified to give a pH-v

Abstract: Process for the purification of an aqueous solution containing alkali metal carbonate, sulphate, and hydroxide or hydrogen carbonate and primarily one at least of the metals belonging to the group formed by vanadium, uranium and molybdenum, in the form of alkali metal salts, and mineral and/or organic impurities, said solutions resulting from an ore attack cycle and being taken off after extraction of the metal being sought, which comprises treating said solutions by means of lime at a temperature which is at most equal to the boiling temperature, to convert the carbonate and hydrogen carbonate present into alkali metal hydroxide, then effecting separation and washing of a first precipitate of calcium carbonate and a liquor which is enriched in respect of alkali metal hydroxide, concentrating it by evaporation to cause production of a second precipitate which essentially comprises alkali metal sulphate, separating it from the hydroxide-rich liquid phase, re-dissolving it in an aqueous medium and treating the

Abstract: Improvement in electrowinning manganese dioxide, or zinc in which the relative concentration of manganese or zinc ions to impurities is enhanced by selectively extracting manganese or zinc ions from a bleed taken from the electrowinning feed stream with an organic extractant, while rejecting impurities, stripping the loaded organics with spent electrolyte, and recycling loaded strip to the electrowinning feed. Stripped organic may be regenerated with an alkaline agent such as calcium oxide or magnesium oxide prior to recycle, and pH may be controlled during extraction by the same means.

Abstract: A process for converting columbium oxyfluoride (CbO.sub.2 F) to columbium oxide (Cb.sub.2 O.sub.5) comprising heating CbO.sub.2 F under select pyrohydrolysis conditions.

Abstract: A process for the removal of arsenic compounds from tungsten and/or molybdenum concentrates by selective extraction, characterized in that the concentrates are extracted with an aqueous solution of a ferric compound at a pH below 2.5 and a temperature of at least 60.degree. C.

Abstract: Rhombohedral system boron nitride is produced by heating a boron material selected from the group consisting of boron oxide, boric acid and an oxygen-containing boron compound capable of forming boron oxide when heated, at a temperature of from 1200.degree. to 2100.degree. C. to vaporize boron oxide and reacting the vaporized boron oxide with hydrogen cyanide or cyanogen gas.

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: Titanium metal values may be recovered from a metal-bearing source containing titanium and iron by subjecting the source to an oxidation treatment and a reductive roast. After having crushed the source to a desired particle size, the reduced source is then leached by treatment with a halogen-containing compound to form soluble halides, following which the soluble titanium halide is precipitated as titanium dioxide by treatment with an iron oxide such as ferric oxide and recovered. The amount of titanium dioxide which is recovered may be optimized by utilizing a reductant such as hydrogen or carbon monoxide in an amount in the range of from about 1.5 to about 4.5 times the stoichiometric amount required to reduce the iron oxide to metallic oxide during the reductive roast.

Abstract: The specification discloses a method for recovering non-ferrous metals such as zinc or copper iron from their concentrates, ores or any other metal containing materials into a solution containing these non-ferrous metals as sulphates and a minimal amount of dissolved iron. The resultant solution is suited without or with minimum pre-purification treatment for conventional electrowinning processes to recover such non-ferrous metals with less difficulties than the previous methods involving complex iron-removal processing. There is disclosed a method for recovering at least one non-ferrous metal soluble in sulphuric acid from a strong sulphuric acid solution containing said metal and iron as sulphates, said method comprising the following consecutive steps:subjecting said solution in a sub-divided form to thermal decomposition in a fluidized bed reactor at a temperature of from 600.degree. to 750.degree. C.

Abstract: Hydrogen is produced in a synthesis gas plant which is subdivided into several units. The units are operated in such a way that concentrated water is separated from the effluent leaving the first unit in a condenser and supplied to the next stage as feed water. The steam produced in the last unit which is most strongly enriched with deuterium relative to the first unit is separated in a condenser and the deuterium-enriched water is introduced into a tank from which the water is supplied to a heavy water production plant as a starting material.