Abstract: This invention relates to submicron carbonitride powders of titanium and, optionally, other transition metals of the fifth (Me.sup.(5)) and sixth (Me.sup.(6)) secondary group of the periodic system of elements which have the following general molar composition: (Ti.sub.L Me.sub.M.sup.(5) Me.sup.(6).sub.1-L-M) (C.sub.1-y N.sub.y).sub.z with 0.50.ltoreq.L.ltoreq.1; 0.ltoreq.m.ltoreq.0.15; 0.ltoreq.(1-L-M).ltoreq.0.50; 0.10.ltoreq.y.ltoreq.0.95 and z.gtoreq.0.90, to a process for the production of these powders and to their use.

Abstract: Improved solvent extraction recovery of tantalum and niobium oxides from an acid solution of raw materials containing such oxides wherein the charged organic solvent [e.g., MIBK] is washed out (a) with 8-16N sulfuric acid and then (b) with water or dilute HF. This avoids the use of a second mineral acid addition after digestion by HF of raw materials (and avoids problems attendant to use a second mineral acid).

Abstract: Sintered composite abrasive material useful in abrasives (grinding wheels, abrasive discs and paper, etc.) and cutting tools, comprising an .alpha.-Al.sub.2 O.sub.3 matrix of sub-micron crystallite size made by sol-gel processing with a dispersed phase therein of mechanically resistant material, preferably essentially isotropic grains, added directly to the sol or gel stage of matrix formation.

Abstract: The metal-values bearing slags of metallothermic processes are separated from metal melts and then fully reduced electrothermally with carbon to form a new metal melt. Slag removed from the new metal melt is essentially free of said metal values.

Abstract: Fluorine content of tantalum and niobium hydroxides is reduced to under 0.5 weight % by washing such hydroxide precipitates (as obtained by HF digestion and solvent extraction) with dilute ammonia (1 to 10%) and then water in two washing stages. The first washing stage includes a partial neutralization and the used wash water of the second stage is advantageously recycled, after adjustment of its ammonia concentration, for use as the first stage washing liquid.

Abstract: Cobalt-bound diamond tool (e.g. for cutting, drilling polishing) composite materials comprising diamond particles in uniform matrix of cobalt-boron alloy with 1-5 weight percent and uniform, stable and controllable matrix hardness of about 200 to 650 HB.sub.30.

Abstract: MCrAlY composite material with platinum and/or rhodium alloying elements as 5-15 wt. % thereof and containing included particles of carbides vanadium, niobium, tantalum, titanium, zirconium, hafnium, chromium, molybdenum and/or tungsten and/or mixtures thereof, enhancing the corrosion- and wear-resistance of such materials at high temperatures.

Abstract: In an advantageous process for producing powdered aluminium alloys which have a catalytic action or are capable of acting as precursors of catalysts, good results are obtained if the alloy is atomized with water and/or a gas at a temperature of 50.degree. to 500.degree. C. above its melting point and then cooled and dried.

Abstract: A molybdenum metal powder having an outer shell coating of MoO.sub.2 is useful in flame spray or plasma spray processes and is prepared by partially oxidizing molybdenum powder in a carbon dioxide atmosphere at temperatures of up to 1200.degree. C.

Abstract: Metal powder agglomerates of individual particles comprising (i) more than 70% by weight of one or more metals selected from the group consisting of the elements molybdenum, rhenium and tungsten and (ii) one or more binder metals selected from the group consisting of iron, cobalt, nickel, copper, silver, gold, palladium, platinum, rhodium, chromium and rhenium, wherein the individual particles have grain sizes of less than 2 .mu.m and all the metal particles lie side by side in uniform random distribution are useful as the powder required for producing shaped, sintered articles in a powder metallurgical preparation.

Abstract: The invention relates to an improvement of the flowability and an increase in the bulk density of high-surface area valve metal powders by means of the addition of finely divided extraneous metal oxides in quantities of up to 5000 ppm, relative to the quantity of metal, before the powder-metallurgical processing of the valve metal powder.

Abstract: The invention relates to a process for treating the surface of valve metals, in particular niobium and tantalum, in the form of agglomerated or non-agglomerated powders, thin foils or molded articles prepared from powder, for use as electrolytic capacitor electrodes, these metals being heated in at least one stage to temperatures of 300.degree. to 2,000.degree. C. under a high vacuum or an inert gas atmosphere and in the presence of chalcogens or chalcogen compounds, excluding oxygen.

Abstract: To produce valve-metal anodes for electrolytic capacitors, reducing agents are added to the already sintered and/or unsintered anode bodies to improve the electrical properties, whereupon heating is carried out at temperatures above the melting point of the reducing agents and below the temperatures conventionally used for sintering the valve-metal anodes.

Abstract: A process for the production of valve metal powder, which is doped with boron or boron compounds, for electrolytic capacitors having a low relative leakage current and a high specific charge. The doping with boron or boron compounds in amounts of up to 0.5 percent by weight, relative to the metal content, can take place either during the production of the metal powder or the green valve metal anodes.

Abstract: A process for the production of agglomerated valve metal powder which comprises heating an admixture of a valve metal powder and a reducing agent in the presence of an inert gas or under high vacuum for a sufficient time and at a sufficiently elevated temperature that agglomeration of the valve metal powder occurs, and removing the reaction products of the reducing agent and the valve metal and any unreacted reducing agent from the agglomerated valve metal powder by subsequent reaction with an inorganic acid. The agglomerated powder can be sintered to prepare valve metal electrodes, e.g., anodes, which can also be prepared by direct sintering of the admixture of the metal powder and the reducing agent.

Abstract: A process for recovering one or more nonradioactive transition metal compounds from an ore containing one or more compounds of said transition metal or metals and further containing at least one complex of a member selected from the group consisting of uranium, thorium, radium, titanium, and rare earth metals, which comprises decomposing said ore in crushed condition by means of an acid so that a portion of the ore is brought into solution in a liquid phase and another portion of the ore remains in a solid phase, said compound or compounds of the transition metal or metals to be recovered passing into only the liquid or into only the solid phase, the uranium in the crushed ore being treated so as to cause substantially all of said uranium to be present in an oxidation state in which it cannot, during the decomposition step, pass into the phase containing the transition metal compound or compounds.

Abstract: A process for the recovery of valuable metals from spent desulfurization catalyst wherein the catalyst, which has not been subjected to oxidative roasting, is thermally reduced in the presence of carbon and calcium oxide.

Abstract: A method for producing tungsten compounds low in phophorus. Calcium tungstate is precipitated from a tungstate solution possibly containing phosphate with a calcium compound. The resulting precipitate is reacted with an alkali carbonate solution under pressure of preferably 15 to 25 bar and the solution resulting is separated from the residue containing substantially all of the phosphate. The resulting solution is collected and is suitable for production of tungsten compositions low in phosphorus.

Abstract: An electrode having an electrical capacitance in excess of 10,000 .mu.C/g prepared by sintering a tantalum powder having a grain size finer than 2.5 .mu.m, and the process of preparation.

Abstract: Raw materials containing tantalum or niobium are treated to obtain aqueous solutions containing fluoroacid complexes of niobium or tantalum. These solutions are decomposed by pyrolysis and calcined to obtain pure oxides of niobium or tantalum. The hydrofluoric acid separated during pyrohydrolysis is recovered and reused. A niobium or tantalum-free raffinate solution obtained, on extraction, with the above aqueous solutions contains dissolved metalloids which are recovered as oxides which are deposable waste products.