Abstract: A process for the production of a valve metal oxide powder, in particular an Nb2O5 or Ta2O5 powder by continuous reaction of a fluoride-containing valve metal compound with a base in the presence of water and calcination of the resultant product, wherein the reaction is performed in just one reaction vessel and at a temperature of at least 45° C. Valve metal oxide powders obtainable in said manner which exhibit a spherical morphology, a D50 value of 10 to 80 ?m and an elevated BET surface area.

Abstract: The present invention relates to a process for the conversion of cobalt(II)hydroxide into cobalt(III)oxidehydroxide (CoOOH) by reaction of the cobalt(II)hydroxide with oxygen in the presence of certain metal compounds. The invention further relates to the use of cobalt(III)oxidehydroxide thus prepared in the preparation of catalysts or catalysts precursors, especially catalysts or catalyst precursors for the conversion of synthesis gas into normally liquid and normally solid hydrocarbons and to normally liquid or solid hydrocarbons, optionally after additional hydrotreatment, obtained in such a conversion process.

Abstract: A process for recovery of vanadium dissolved in acid solutions or liquors by precipitating it out as vanadium pentoxide. Separation is carried out by adding calcium hydroxide, quicklime or calcium carbonate to the acid solution or liquor, producing a precipitate of vanadium pentoxide, which is separated from the liquid by physical methods such as filtration or centrifugation. If the acid is other than sulfuric acid, the calcium which remains dissolved in the solution or liquor by the addition of calcium hydroxide, quicklime or calcium carbonate, is removed by adding sulfuric acid, to produce solid calcium sulfate and water. The calcium sulfate is extracted from the solution or liquor or liquor by filtration or centrifugation. With sulfuric acid solution or liquors, after addition of the neutralizing agent, a solid precipitate of vanadium pentoxide and calcium sulfate is formed, which is then separated from the solution or liquor.

Abstract: Process wherein the vanadium present in the chromium ore chromite is recovered as vanadium pentoxide during the course of the fusion of the chromium ore with alkali and its work-up to produce sodium chromate solution and sodium dichromate.

Abstract: A fuel reforming system comprises a reforming catalyst section (4) performing reformate reactions on supplied fuel gas, a membrane hydrogen separator (5) extracting hydrogen from the reformate gas, a supply device (8–14) supplying combustion gas for heating the membrane reactor (2), a sensor (16) for detecting the temperature of the membrane hydrogen separator (5) and a controller. The supply device supplies combustion gas to the membrane reactor (2) before the reforming catalyst section starts reformate reactions during startup of the membrane reactor (2). Furthermore the supply device stops supply of combustion gas to the membrane reactor (2) when the temperature of the membrane hydrogen separator (5) is greater than or equal to a target temperature. Thereafter the fuel supply device supplies fuel to the fuel reforming catalyst section (4). In this manner, hydrogen embrittlement in the membrane hydrogen separator can be avoided.

Abstract: Processes for treating iron containing waste streams are provided. According to these processes, metal-containing compounds, particularly iron oxides are produced. These methods may, for example, be used in the processing of the waste streams from the chlorination of titanium-bearing raw materials and involve the use of certain combinations of neutralization and precipitation steps.

Abstract: The method relates to a pyrometallurgical and hydrometallurgical process for the recovery and recycling of lithium and vanadium compounds from a material comprising spent rechargeable lithium batteries, particularly lithium metal gel and solid polymer electrolyte rechargeable batteries. The method involves providing a mass of the material, hardening it by cooling at a temperature below room temperature, comminuting the mass of cooled and hardened material, digesting with an acid its ashes obtained by incineration, or its solidified salts obtained by molten salt oxidation, or the comminuted mass itself, to give a mother liquor, extracting vanadium compounds from the mother liquor, separating heavy metals and aluminium therefrom, and precipitating lithium carbonate from the remaining solution.

Abstract: The invention relates to a process for treating tantalum and/or niobium containing raw materials such as wastes, slags, concentrates and ores. The tantalum and/or niobium containing raw materials are processed by repeated use of a solution of ammonium fluoride. From the tantalum and niobium containing aqueous solution a mixture of fluorides and oxide fluorides of tantalum and niobium are transformed into a firm condition. At an extraction stage pure, aqueous solutions containing fluoro acid complexes of niobium and fluoroammonium complexes of tantalum are obtained. From these tantalum and niobium are obtained as oxides in pure form by precipitating them as fluoride containing oxide hydrates by addition of ammonia. The obtained oxide hydrates are transformed into pure oxides by calcining at high temperatures.

Abstract: A process for producing valve metal oxides, such as tantalum pentoxide or niobium pentoxide with a narrow particle size distribution within a desired particle size range, is provided. According to the process of the present invention, the valve metal fraction from digestion of valve metal material containing ore is processed under controlled temperature, pH, and residence time conditions to produce the valve metal pentoxide and pentoxide hydrates. Also, disclosed are new tantalum pentoxide and niobium pentoxide products and new tantalum pentoxide precursors and niobium pentoxide precursors.

Abstract: Highly pure tantalum compounds are made by slurrying hydrated ammonium tantalum oxide or tantalum hydroxide with concentrated sulfuric acid followed by dissolution with concentrated hydrofluoric acid. After diluting the concentrated acidic solution with water, a soluble potassium compound is added to precipitate a highly pure potassium fluorotantalate. Further steps are used to convert the highly pure potassium fluorotantalate into a highly pure tantalum oxide.

Abstract: To process vanadium-containing residues, the residues are leached in an aqueous slurry with introduction of SO.sub.2, the undissolved solids are removed. To effect a processing which is simple, economical and ecologically satisfactory, vanadium content is precipitated as a tetravalent vanadium compound from the sulfate solution at a pH from 7 to 9 by an addition of alkali metal hydroxide and the precipitate is removed from the alkali metal sulfate solution.

Abstract: A process for purifying an acidic technical-grade iron chloride solution formed from cyclone dust from the production of TiO.sub.2 in accordance with the chloride process by adjusting the pH with a first neutralizing agent and thereafter introducing the pH adjusted solution in a controlled manner into a solution containing a second neutralizing agent. In this process undesired ions which are to be separated, such as chromium, vanadium, zirconium and/or niobium, precipitate in the form of efficiently filterable hydroxides which can be separated industrially under economical conditions by filtration. The filter cake is non-hazardous and can safely be disposed of by dumping. Calcium carbonate is the preferred neutralizing agent, and the pH adjustment may also advantageously be effected by using scrap iron or by using iron sinters with reduction of any Fe(III) ions before the second neutralization step.

Abstract: A process for the preparation of a vanadium oxide colloidal dispersion is provided. The process includes a step of hydrolyzing vanadium oxoalkoxide with an excess of water to form a vanadium oxide colloidal dispersion containing at least a minimum effective amount of vanadium and no greater than about 3.5 wt-% vanadium, preferably containing about 0.3 wt-% to about 2 wt-% vanadium. The process can be carried out in the presence of an organic polymer or prepolymer to form a polymeric vanadium oxide colloidal dispersion.

Abstract: In order to treat metal chlorides obtained in the form of dust collector solids in the production of titanium dioxide by the chloride process, the inert constituents, especially particulate coke, is separated then the metals are selectively precipitated and a maturing phase under oxidative conditions is provided for. The residue consisting of metal hydroxides is also not thixotropic in the absence of inerts. As a result, the material to be deposited has been cut in half.

Abstract: For economical and assured separation of chromium, vanadium and titanium ions from acidic waste waters, which accrue in great quantities in preparation of titanium dioxide, the pH is first raised to around a value of 3 by addition of dolomite brick powder. Directly thereafter, the pH is fine tuned into the range of 4.3 to 4.7 through addition of calcium hydroxide and/or sodium hydroxide, and the hydroxides are separated with the aid of a flocculating agent. Since iron ions and calcium ions remain mainly dissolved in the waste water through such selective precipitation, only a relatively small volume of slush has to be disposed of.

Abstract: A process of treating metal chloride wastes produced by chlorination of titanium ore comprises the steps of:(a) leaching said metal chloride wastes in a hydrochloric acid (HCl)-containing solution to obtain a solution containing solids and dissolved metals,(b) separating said dissolved metals from said solids present in the solution obtained in step (a) to obtain a liquid and a residue,(c) selectively precipitating the metals as their hydroxides by adding a neutralizing agent to the liquid obtained in step (b),(d) separating the precipitate of metal hydroxides obtained in step (c) from the liquid to obtain a residue, and(e) dewatering the residue obtained in step (d).

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: A process for the extensive removal of undesirable metal ions, particularly vanadium ions, in the course of the concentration of dilute iron(II) sulfate-containing sulfuric acid solutions. The sulfuric acid solutions are concentrated by the evaporation of water and the separation of iron(II) sulfate to a content of 60 to 70% by weight H.sub.2 SO.sub.4. According to the invention, the content of trivalent titanium in the solution is adjusted such that the content of trivalent iron does not exceed 0.1 g/l. The trivalent titanium may be added from the outside, if not already present in an adequate amount in the solution, or may be formed in situ from the tetravalent titanium present in the solution by the addition of a reducing agent. Prior to the final concentration, part of the iron may be precipitated and separated as iron(II) sulfate heptahydrate by means of preconcentration and cooling of the preconcentrated sulfuric acid solution.

Abstract: A process is provided for the recovery of vanadium and nickel values from petroleum residues and, in particular, from Flexicoke. In the process, Flexicoke is blended with an alkali metal source, such as sodium sulfate or sodium carbonate, and then roasted in an oxygen-containing gas until carbon is removed and a fused mixture is obtained. Thereafter, the vanadium is leached from the mixture with an aqueous solution, and nickel is contained in solids remaining from the leaching.

Abstract: Niobium (V) and tantalum (V) halides are converted to Nb.sub.2 O.sub.5 and Ta.sub.2 O.sub.5 that are free of detectable levels of halide in a two step process. In the first step, the metal halide is reacted with an alcohol and with a replacement species, such as ammonia, which reacts with the halide. This produces a metal alkoxide which is soluble and a halide salt of the replacement species which is insoluble in the alcohol and precipitates. After physically separating the alkoxide in alcohol solution from the precipitate, in a second step, the metal alkoxide is hydrolyzed with purified water to produce the oxide.

Abstract: Carrier supported catalysts are prepared, comprising metal ions which in their most stable state occur as anions or as higher-valency cations which exhibit a poor interaction with the support material by deposition-precipitation through increasing the hydroxyl ion concentration in homogeneous solution. According to the invention, prior to deposition-precipitation the metal ions are electrochemically reduced to soluble metal ions having a lower valency. Preferably, the pH value of a suspension of the support to be loaded in a solution of the electrochemically reduced metal ions is homogeneously increased by hydrolysis of compounds such as urea or isocyanate, or by the controlled injection of an alkaline solution below the surface of the suspension.

Abstract: Metal values and alumina are recovered from spent, usually oily, catalysts by oxygen pressure leaching with sodium hydroxide and/or sodium aluminate to dissolve molybdenum, vanadium and/or tungsten and provide a solid, filterable residue containing alumina and cobalt and/or nickel, the residue is digested with sodium hydroxide to give a sodium aluminate solution and a residue enriched in nickel and/or cobalt, alumina is recovered from the sodium aluminate solution as a solid and the remaining supernatant solution is recycled to the oxygen pressure leaching step wherein the alumina content of the aluminate solution is precipitated and a bleed for metals in the aluminate solution is provided.

Abstract: Spent hydrodesulfurization catalysts containing alumina, at least one metal from the group consisting of molybdenum, tungsten and vanadium and at least one metal from the group consisting of nickel and cobalt, sulfur, and, usually, residual oil are oxygen pressure leached at a temperature of at least about 400.degree. F. with a base from the group consisting of sodium hydroxide and sodium aluminte in at least stoichimetric amount to yield a solution having a pH between about 7 and 9 containing dissolved molybdenum, vanadium and any tungsten which may be recovered and a readily filterable residue containing aluminum, nickel and cobalt which may be worked up to recover the valuable constituents, with overall processing being accomplished in an environmentally acceptable manner.

Abstract: A process for pretreatment at high temperature by means of an aqueous pretreatment solution, of crushed ores containing at least one usable metal element, whose gangue contains argillaceous compounds which, in the attack operation for making use of the ore, are capable of forming a stable plastic suspension in the presence of water, which makes it virtually impossible subsequently to separate the liquid and solid phases by virtue of its character being such that it cannot be subjected to filtration and/or settlement, which is characterized in that, to cause stabilization of the argillaceous gangue before the operation of subjecting the ore to attack and to produce easy separation of the liquid and solid phases after the attack operation, the ore, the granulometry of which is at most equal to the liberation sieve mesh size of the metal or metals to be put to use, and before being subjected to the attack operation for making use of the ore, is brought into contact with an aqueous pretreatment solution containin

Abstract: A process for the recovery of columbium values from a columbium-containing aqueous hydrofluoric acid solution. The columbium-containing solution is heated, with agitation, to cause evaporation and hydrolysis, resulting in the formation of a slurry from which columbium oxyfluoride can be separated and recovered.

Abstract: Metals such as nickel and vanadium can be recovered from scrubber waste by first lowering the pH of the waste to a level at which its major metal constituents will be substantially solubilized, and then raising the pH in increments to successively precipitate the metals it contains.

Abstract: A method for precipitating vanadium from vanadium bearing liquors comprises adjusting the pH of the vanadium bearing liquor with a precipitating agent selected from the hydroxides of Na, K and Ca to a range of about 5.5 to 6.5, preferably 6.0 to 6.2 so as to precipitate vanadium in the trivalent and tetravalent states. Remaining traces of vanadium are then cemented by additions of calcium hydroxide, calcium oxide or mixtures thereof. The dried precipitate is then heated in the presence of air and Na and/or K so as to form a reaction product in the form of a water soluble salt which, when dissolved in water, results in vanadium in its pentavalent state.

Abstract: A process is provided for the production of vanadyl hydrate including solvent extraction and stripping steps. The vanadyl hydrate is then reacted with carbon to produce vanadium carbide.

Abstract: A method for the removal and recovery of vanadium from a vanadium bearing material by leaching the vanadium bearing material in the presence of a leach promoter and removing the vanadium so leached from the leaching solution by precipitation. The leaching promoter forces the vanadium present in the vanadium bearing material into solution.

Abstract: Disclosed is method of recovering tantalum from silicon-containing tantalum scrap, which comprises dissolving said scrap in an inorganic acid, bringing the resulting solution into contact with an anionic exchange resin, followed by washing said anionic exchange resin with (a) a solution of 3 to 10 mol/l. of hydrofluoric acid or (b) a solution of strongly acidic medium containing 0.01 to 0.5 mol/l. of hydrofluoric acid and 1 to 6 mol/l. of a strong acid, and then washing the same with an aqueous solution of a mixture composed of hydrofluoric acid, aqueous ammonia and an ammonium salt.

Abstract: A carbonaceous material containing vanadium is reacted with an oxidizing gas in a molten salt pool containing an alkali metal carbonate. Vanadium values present in the carbonaceous material are converted to water-soluble vanadium compounds which are recovered from the melt and reacted with a strong acid to precipitate the vanadium values as insoluble vanadates. The vanadates are recovered as product or optionally further converted to vanadium pentoxide.

Abstract: In a process for producing tantalum concentrates from ores containing tantalum oxides, tantalic acid or its salts together with rutile type titanium dioxide in mixed crystals, the ores are treated in a sulfuric acid of a concentration not lower than 50% by weight with heating at a temperature from 200.degree. C. to the boiling point of said sulfuric acid, and then the above-treated products are treated with a reducing agent in an aqueous solution of sulfuric acid of a concentration lower than 50% by weight to dissolve the titanium component to thereby obtain tantalum concentrates as solid products.

Abstract: The invention disclosed provides a process for recovering niobium values from aqueous hydrofluoric acid solutions by evaporating said solution to dryness and baking the residue at temperatures of 150.degree. to 250.degree. C. The solid residue is niobium oxyfluroide (NbO.sub.2 F) which may then be exothermically reduced with aluminum in the presence of an alloying element such as iron, nickel, or chromium to produce a niobium alloy. The evaporated hydrofluoric acid may be recovered by condensing or absorbing the evolved vapors.

Abstract: Disclosed is a method of electrolyzing alkali metal chloride brine. The method comprises feeding fortified brine to an electrolytic cell, passing an electrical current through the cell, and withdrawing depleted brine from the cell. Hydrochloric acid is added to the depleted brine to dechlorinate it; and the depleted, dechlorinated brine is then contacted with solid salt to refortify the brine. The solid brine is a source of heavy metal impurities. Sodium carbonate and barium carbonate are added to the refortified brine in order to precipitate calcium and sulfate ions therefrom. The precipitate is then separated from the refortified brine in order to obtain a refortified, purified brine. According to the disclosed method, ferrous ion and sufficient hydroxyl ion are added to the dechlorinated, depleted brine prior to its refortification in order to maintain the pH thereof above about 7 during fortification.