Abstract: Chromium is selectively precipitated from waste solutions by means of benzoate ion. The resulting chromium benzoate complex is separated, washed and treated with either base or sulfuric acid to recover the benzoate and a chromium hydroxide product.

Abstract: Spent aqueous hexavalent chromium solutions containing trivalent chromium ions and extraneous metal ions are oxidized by placing said exhausted Cr.sup.+6 solution in the anode compartment of an electrolytic cell as the anolyte, said cell being separated into anode and cathode compartments by at least one cation selective membrane, said cathode compartment containing a catholyte, and impressing a direct current across the anode and cathode of said cell of a difference in potential sufficient to promote the oxidation of trivalent chromium in the solution in said anode compartment to hexavalent chromium while extraneous metal ions in the anolyte solution migrate through said membrane into the catholyte of said cathode compartment where copper ions are plated onto said cathode. The anode compartment consists of a removable and portable container consisting essentially of a framework having side members secured thereto, at least one of said anode members comprising a cation selective membrane.

Abstract: Metal values are recovered from ore concentrates by means of dry grinding, followed by a two-stage leaching process in which the ground concentrate is first leached with sulfuric acid at a temperature of about 90.degree. to 100.degree. C. to selectively leach nickel and iron. The residue is then leached with a solution comprising sulfuric acid and NaOCl or H.sub.2 O.sub.2 to extract platinum, palladium, copper and gold.

Abstract: Zirconium is selectively precipitated from aqueous solutions containing zirconium and uranium by treatment with a precipitant consisting of tartaric acid or a tartrate.

Abstract: A method of separating wrought and cast aluminum from a scrap mixture containing the two is disclosed. In this method, the scrap mixture is first heated to a temperature above the solidus temperature of the cast aluminum scrap. At this temperature, the scrap mixture is crushed thereby causing the cast aluminum to fragmentize into small pieces while merely causing flattening of the wrought aluminum. By using an appropriately sized screen, the cast aluminum fragments can then be separated from the wrought aluminum.

Abstract: A chromatography developing chamber for developing thin layer or paper chromatographic materials comprising an elongated sleeve closed at one end, open at the other end and having a peripheral wall therebetween, such as a cylindrical sample tube. A ledge projecting inwardly from a peripheral wall of the sleeve is positioned adjacent the closed end to provide a surface for supporting the chromatographic material in the chamber. A liquid elution solvent fills the chamber from the closed end to a level below the ledge such that the chromatographic material on the ledge is supported out of contact with the solvent during a first stage of developing. The ledge permits the material to be readily displaced therefrom to fall into the solvent during a second stage of developing. The material may be displaced from the ledge by vibration, as by tapping the chamber, or by magnetic means.

Abstract: Ferrochromium alloys are prepared by vacuum reduction of chromite concentrate by means of a carbonaceous reductant, followed by melting in the presence of slag-forming materials to produce the alloy and a separate slag phase. Preferably, CaO is employed as an ingredient in both the reduction step and the melting step.

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: Asymmetric reverse osmosis membranes are made from synthetic aromatic polyimides having a relatively high predominance of polar groups in the polymer backbone. A polar/non-polar group ratio of from 2:2 to 2:7 per imidized nitrogen link is required. Such membranes can be fabricated using conventional casting equipment by providing a solution of the polyimide in a good solvent and a poor solvent, the poor solvent being compatible with solution components at poor solvent/good solvent ratios of at least 1:1 up to about 7:1, casting a film of such solution, and partially evaporating the exposed surface of the cast film for 100.+-.30 seconds prior to gelation.

Abstract: Efficient dewatering of slimes is achieved by admixing the slimes with a flocculating agent, followed by mechanical manipulation to effect rapid removal of water and consolidation of solids. The required mechanical manipulation may be accomplished, e.g., by tumbling the mixture through a rotating cylindrical screen or by passing it across a vibrating screen.

Abstract: A packing media for column chromatography having multiple separation characteristics comprises adsorbent carbon powder particles adhered to the surfaces of individual particles of a molecular size exclusion gel polymer.

Abstract: An alloy of thorium and a Group VIII transition metal is oxidized, for example in air, and subsequently reduced, for example with hydrogen gas, to produce a high surface area catalyst containing thorium oxide and one or more Group VIII transition metals. The catalyst thus produced may be used as such or may be further treated to enhance its activity.

Abstract: The present invention provides a method for clarifying slimes. This method comprises the steps of treating a slime with a unique flocculant and separating the clarified slime from the aggregated floccules. The flocculant is a stabilized aqueous-base magnetic colloid that contains colloidal magnetic particles and at least one surfactant, such as dodecylamine. The magnetic colloid becomes unstable and the magnetic particles thereof irreversibly flocculate when the magnetic colloid is sufficiently diluted.

Abstract: A conventional sputtering chamber is modified to include two elongated hollow tubes which accommodate an elongated workpiece in the form of a tube or strip, of lesser diameter, during a sputter-coating operation. During the sputtering operation, the workpiece is simultaneously rotated and moved back and forth beneath at least one sputtering target to receive a uniform coating thereon.

Abstract: Highly active catalysts, suitable for use in hydrogenation and other reactions, are prepared from an alloy of one or more of the Group VIII transition metals with a Group IIA metal, a Group IVB metal, or an actinide. The alloy is ground to the desired particle size and is thereafter reacted with a gas, such as carbon monoxide and hydrogen, to form an intimate physical admixture of the Group VIII metal or its corresponding carbide with the oxide of other metal.

Abstract: A method for the separation of bismuth from a complex chloride solution obtained by leaching with chloride reagents ores containing bismuth and high concentrations of other metals comprising adding to said complex chloride solution at least a stoichiometric amount of a precipitating agent selected from the group consisting of hexamminecobalt (III) salts and hexamminechromium (III) salts soluble in said solution to precipitate said bismuth as a hexamminecobalt (III) bismuth salt or a hexamminechromium (III) bismuth salt and separating said precipitate from said solution.

Abstract: The present invention provides a process of electroplating a platinum-rhodium alloy coating of predetermined composition and predetermined thickness on a metal substrate. The composition is substantially uniform throughout the electrodeposited coating. The process includes the steps of electrolytically dissolving an anode made of platinum or rhodium into a molten cyanide bath to prepare separately a platinum bath and a rhodium bath, forming a mixed bath having a predetermined ratio of platinum to rhodium from the separate platinum and rhodium baths, and electroplating platinum and rhodium onto a metal substrate, using a predetermined electrical charge and alternating a platinum anode with a rhodium anode, while monitoring and controlling the deposition potential of the metal substrate. This coating substantially corresponds in composition to the composition of the mixed bath. The process is carried out in a dry, inert gas environment.

Abstract: Lithium is recovered from low-grade ores, such as clays, by addition of CaO or CaCO.sub.3 and chlorination with H.sub.2 O-HCl vapor to convert the lithium to soluble LiCl.

Abstract: Lead is electrowon from aqueous phosphorus-containing fluosilicic acid solution by deposition on a lead cathode, employing an anode comprising a titanium substrate and an electrodeposited lead oxide coating having a uniform, dense grain size and structure.

Abstract: There is disclosed a process for extracting uranium values from a uranium-containing carbonaceous ore such as lignite. This process includes the step of treating the ore with an aqueous leach solution containing a water-soluble ferric salt.