Abstract: A process for selective separation of strontium-82 and strontium-85 from proton irradiated molybdenum targets is provided and includes dissolving the molybdenum target in a hydrogen peroxide solution to form a first ion-containing solution, passing the first ion-containing solution through a first cationic resin whereby ions selected from the group consisting of molybdenum, niobium, technetium, selenium, vanadium, arsenic, germanium, zirconium and rubidium remain in the first ion-containing solution while ions selected from the group consisting of rubidium, zinc, beryllium, cobalt, iron, manganese, chromium, strontium, yttrium and zirconium are selectively adsorbed by the first resin, contacting the first resin with an acid solution capable of stripping adsorbed ions from the first cationic exchange resin whereby the adsorbed ions are removed from the first resin to form a second ion-containing solution, evaporating the second ion-containing solution for time sufficient to remove substantially all of the acid

Abstract: A process for producing titanium dioxide which discharges no waste is disclosed. In a first step, a sulfuric acid solution containing titanium ion with one or more kinds of metal ions is contacted with a first organic solvent to extract the titanium ion as a sulfuric acid complex. The organic solvent containing the extracted titanium as a sulfuric acid complex (titanyl sulfate) is contacted with an aqueous liquid to strip the titanium into the aqueous liquid and regenerate the first organic solvent. In a second step, the aqueous liquid containing the titanium is subjected to hydrolysis to form insoluble titanium hydroxide, and the titanium hydroxide is washed with dilute sulfuric acid and/or clear water.

Abstract: The invention relates to novel electrochromic materials useful as electrochromic electrodes in eletrochromic cells and to their preparation process. These materials are constituted by at least one transition metal oxyhydroxide chosen from among H.sub.2 Ti.sub.3 O.sub.7 and HNbWO.sub.6, H.sub.2 O or by a thin film obtained by vacuum evaporation of at least one of these oxyhydroxides.

Abstract: The invention relates to a process for separating iron and/or zirconium from the actinides and/or lanthanides present in an aqueous acid solution by means of a propane diamide.According to the invention, use is made of a pentasubstituted propane diamide of formula: ##STR1## in which R.sup.1, R.sup.2 and R.sup.3, which can be the same or different, are alkyl radicals, which can have 1 or 2 oxygen atoms in their chain.To maintain the iron in aqueous solution, a choice is made of an appropriate propane diamide of formula (I) with R.sup.3 representing a C.sub.12 to C.sub.25 alkyl in order to have different extraction kinetics between Fe and the actinides or lanthanides, or an additive is added to the aqueous solution, e.g. oxalic acid or sodium nitrate.

Abstract: A process for selective separation of germanium-68 from proton irradiated molybdenum targets is provided and includes dissolving the molybdenum target in a hydrogen peroxide solution to form a first ion-containing solution, contacting the first ion-containing solution with a cationic resin whereby ions selected from the group consisting of molybdenum, niobium, technetium, selenium, vanadium, arsenic, germanium, zirconium and rubidium remain in a second ion-containing solution while ions selected from the group consisting of rubidium, zinc, beryllium, cobalt, iron, manganese, chromium, strontium, yttrium and zirconium are selectively adsorbed by the first resin, adjusting the pH of the second ion-containing solution to within a range of from about 0.7 to about 3.

Abstract: A new chemical separation process was developed in this invention using 2-methoxyethanol or methyl collosolve (MCS) and ethylene glycol (EG) as separation agents, to separate the valuable extractants such as di(2-ethylhexyl) phosphoric acid(D2EHPA), tri n-octyl-phosphine oxide (TOPO) from spent solvent and to recover the extractants. The process comprises separation and recovery sections. In the separation section the extractants were removed by the polar solution from spent solvent based on the difference of miscibilities. In the recovery section, the polar solution loaded with extractants was distillated under vacuum to remove MCS as a distillate and water was added to the bottom product to facilitate the separation of the extractants. By using this novel process, 99% of D2EHPA and 70% of TOPO in the spent solvent were separated and 98% of D2EHPA was recovered. MCS and EG can be regenerated and reused in the process.

Abstract: A process for separating zirconium values from hafnium values wherein an aqueous solution of ZrCl.sub.4 and HfCl.sub.4 is contacted with NH.sub.4 SCN, feeding the resultant solution into a solvent extraction system containing aqueous HCl and MIBK, separating off the solvent phase containing MIBK, HSCN, hafnium thiocyanate complex, and any decomposition products of HSCN to leave the aqueous phase raffinate containing NH.sub.4 Cl, zirconium oxide-chloride and low concentrations of HSCN, scrubbing the hafnium values from the separated solvent phase, treating the scrubbed solvent phase containing MIBK and HSCN with NH.sub.4 OH to convert the HSCN to NH.sub.4 SCN, separating the NH.sub.4 SCN from the treated solvent phase, treating the separated solvent phase to remove essentially all thiazolines, and scrubbing residual HSCN from the raffinate with the desulfurized solvent phase.

Abstract: The thermal neutron capture cross-section of zirconium may be altered by altering its natural isotope distribution through a steady state chromatographic separation of these isotopes using an anion exchange resin as the stationary phase of the chromatographic column. Zirconium is dissolved in a very strong acid which causes the formation of a zirconium anion, such as the ZrOCl.sub.4.sup.-2 anion formed in six normal hydrochloric acid, and eluted off the column with a weaker acid. Distinct elution volumes representative of each isotope are collected. In a preferred embodiment, the process also separates the zirconium from hafnium and the other impurities normally present in the product obtained by chlorinating zircon sand and utilizes a continuous annular chromatograph.

Abstract: A process for selective separation of strontium-82 and strontium-85 from proton irradiated molybdenum targets comprises dissolving the molybdenum target in a hydrogen peroxide solution to form a first solution containing ions selected from a group consisting of molybdenum, niobium, technetium, selenium, vanadium, arsenic, germanium, zirconium, rubidium, zinc, beryllium, cobalt, iron, manganese, chromium, strontium, and yttrium; passing the solution through a first cationic resin whereby ions selected from a group consisting of zinc, beryllium, cobalt, iron, manganese, chromium, strontium, yttrium a portion of zirconium and a portion of rubidium are selectively absorbed by the first resin; contacting the first resin with an acid solution to strip and remove the absorbed ions from the first cationic exchange resin to form a second solution; evaporating the second solution for a time sufficient to remove substantially all of the acid and water from the solution whereby a residue remains; dissolving the residue i

Abstract: A scrub solution is made up for use in starting up a hafnium liquid-liquid extraction system. An aqueous zirconium oxychloride-containing solution is contacted with methyl isobutyl ketone containing less than 1 Molar thiocyanic acid. The aqueous solution is maintained at a chloride concentration of 1.6 to 3.5 Normal (as HCl) by addition of concentrated hydrochloric acid. Ammonium thiocyanate is added to the acidified aqueous stream to produce thiocyanic acid. The high acidity of the aqueous solution drives the thiocyanic acid into the methyl isobutyl ketone without the chloride anions having a depressing affect on the transfer. The thiocyanic acid-containing MIBK may then be used as a scrubbing solvent to start up the hafnium extraction system.

Abstract: A process for producing nuclear grade zirconium and a liquid-liquid separation circuit for separating zirconium from hafnium are provided. The process employs an aqueous feed of ZrOCl.sub.2 in the presence of thiocyanate, an organic solvent and acid and a series of high mass transfer efficiency pulse columns in which are conducted the iron extraction, hafnium extraction, zirconium stripping, hafnium scrubbing and zirconium and hafnium thiocyanate recovery processes required to produce substantially hafnium-free nuclear grade zirconium. A feed zone mixer-settler separates thiocyanate and zirconium injection points and permits the prestripping of zirconium prior to the main stripping operation. All of the scrubbed solvent and the thiocyanate are regenerated. Higher concentrations, smaller flows, and compact equipment result in the present process requiring substantially reduced in-process inventories as compared to previously known Zr/Hf separation processes.

Abstract: A simple, low cost continuous process for separating and purifying zirconium and hafnium which eliminates liquid waste and facilitates the management of RCRA and LLW wastes is provided. An aqueous zirconium and hafnium--containing feed solution is prepared and fed to a continuously rotating annular chromatograph containing a bed of acid exchange resin. An acid eluant, such as hydrochloric acid, nitric acid, phosphoric acid or the like, is fed through the acid exchange bed while chromatograph is rotating, which separates the feed into substantially pure zirconium and hafnium fractions and into RCRA and LLW waste fractions. The zirconium and hafnium are processed further into nuclear quality zirconium and hafnium metals. The acid eluant is recycled for reuse in the chromatograph, and the RCRA and LLW waste fractions are disposed of in solid form.

Abstract: The isotopes of zirconium can be partially or completely separated by loading an aqueous solution of an ionic compound of zirconium onto a cationic exchange resin with pentavalent phosphorus derived active groups which serves as the stationary phase of a chromatograph, eluting the compound with an aqueous acid and collecting distinct elution volumes representative of each isotope. In a preferred embodiment, the eluant is a strong mineral acid, such as hydrochloric acid and the chromatograph is of a type, such as a continuous annular chromatograph, that it can be operated in a continuous, steady state manner.

Abstract: The isotopes of zirconium can be partially or completely separated by loading an aqueous solution of an ionic compound of zirconium onto a cationic exchange resin which serves as the stationary phase of a chromatograph, eluting the compound with an aqueous acid and collecting distinct elution volumes representative of each isotope. In a preferred embodiment, the eluant is a strong mineral acid, such as hydrochloric acid and the chromatograph is of a type, such as a continuous annular chromatograph that it can be operated in a continuous, steady state manner.

Abstract: Cations and anions contained as impurities in a spent organic solvent can be removed by an alkaline aqueous solution passing through inside of hydrophobic porous membrane such as hollow fibers for capturing anions and by an acidic aqueous solution passing through inside of hydrophobic porous membrane such as hollow fibers for capturing cations at the same time so as to regenerate the organic solvent. An apparatus suitable for removing cations and anions simultaneously from the spent organic solvent is also provided.

Abstract: The processing of an aqueous zirconium chloride solution contaminated with iron, typically iron chloride (FeCl.sub.3), for removing the iron is improved by flowing a suitable solvent, such as methyl isobutyl ketone (MIBK) solution, countercurrent to the flow of the zirconium chloride solution at preferably a ratio of about 0.1 to about 0.25 in a solvent extraction column of from ten to fifteen theoretical stages, preferably a pulse column, and by recovering the solvent for recycling free of iron by distillation of the iron-loaded solvent in a packed, steam-stripper, distillation column to save energy and to avoid problems created by tar formation in the conventional solvent extraction system normally used.

Abstract: There is provided a method for pillaring a layered silicate, such as kenyaite, with polymeric oxide by using a single step treatment with a mixture of swelling agent and pillar precursor. The swelling agent may be an organic cation, such as a cetyltrimethylammonium cation, and the pillar precursor may be a compound which is capable of hydrolyzing to form a polymeric oxide. Tetraethylorthosilicate is an example of such a pillar precursor.

Abstract: A method for manufacturing titanium oxide, comprising bringing a sulfuric acid solution containing predominantly titanium ion together with one or more kinds of metal ions into contact with an organic solvent containing one or more species selected from the group of oxygen-containing organic solvents, alkyl amines, and alkyl aryl amines to extract the titanium ions in a form of a sulfuric acid complex from the sulfuric acid solution, and bringing the organic solvent containing the extracted titanium into contact with water or an aqueous dilute sulfuric acid solution to inversely extract the titanium from the organic solvent to the water or the dilute sulfuric acid solution and to regenerate the organic solvent.

Abstract: The isotopes of zirconium can be partially or completely separated by loading an essentially anhydrous alcoholic solution of an ionic compound of zirconium onto a cationic exchange resin with pentavalent phosphorus derived active groups which serves as the stationary phase of a chromatograph, eluting the compound with an essentially anhydrous alcoholic solution of hydrogen chloride and collecting distinct elution volumes representative of each isotope. In a preferred embodiment, the active groups of the cation exchange resin are derived from di-2-ethylhexyl phosphoric acid, tri-n-octyl phosphine oxide or tributyl phosphate and the chromatograph is of a type, such as a continuous annular chromatograph that it can be operated in a continuous steady state manner.

Abstract: A method of preparing colloidal zirconium oxide sols having substantially uniformly spherical particles in the size range of from about 0.01 to about 2.0 microns is described. The process comprises the steps of(A) preparing a liquid mixture comprising at least one zirconium salt and a compatible liquid vehicle;(B) contacting said liquid mixture with an anion exchange resin for a period of time sufficient to form a zirconium hydrate sol having a pH of at least about 5.0; and(C) recovering the zirconium hydrate sol from the resin. Colloidal size zirconium oxide powders can be prepared from the colloidal zirconium oxide sols by drying and calcining the sols at an elevated temperature. The zirconium oxide powders obtained in accordance with the present invention can be stabilized by the incorporation of certain stabilizers such as yttrium oxide, lanthanum oxide, cerium oxide, calcium oxide and magnesium oxide.

Abstract: A method for neutralizing a sulfuric acid solution containing predominantly Zn ion, comprising adding, to the sulfuric acid solution, at least one compound selected from the group of chlorine-containing compounds of Na ion, K ion, Mg ion, Ca ion, and NH.sub.4 ion in an amount at least chemically equivalent to SO.sub.4 ion contained; and then bringing the sulfuric acid solution into contact with an organic solvent composed of one or more species selected from the group of oxygen-containing organic solvents and alkylamine organic solvents to extract Zn ion from the sulfuric acid solution as a chloride complex to the organic solvent. The sulfuric acid solution after extraction of Zn ion is further treated by addition of an oxidizing agent or by an electrochemical means to convert Fe.sup.2+ into to Fe.sup.

Abstract: High-grade titanium dioxide is produced by(a) reacting ilmenite or titanium-containing slag with sulfuric acid,(b) dissolving the material from (a) with water or dilute sulfuric acid,(c) separating insolubles from (b) to obtain a black solution containing titanyl sulfate and foreign metal salts,extracting titanyl sulfate from the black liquor with sulfuric acid and an organic medium containing an organophosphorus compound, separating the foreign metal salts in an aqueous extract phase, recovering titanyl sulfate from the organic extract phase, andhydrolyzing the titanyl sulfate to titanium oxide hydrate.

Abstract: Solid, transparent, non-vitreous, microspheres (zirconia-silica) are formed by extractive gelation (extracting carboxylic acid away from zirconyl carboxylate) of a sol in liquid medium such as hot peanut oil. Zirconyl carboxylate precursor sol is prepared and added in droplet form to the liquid extractant (peanut oil) at an elevated temperature at which a carboxylic acid is liberated from the zirconyl carboxylate. The droplets remain in the extractant for sufficient time to form stable gel spheroids which are separated from the extractant and fired to convert them to durable spheroids useful as lens elements in retroreflective sheeting.

Abstract: This is an improvement to a process for making zirconium metal from uranium-containing zircon ore. The process being improved is of the type which utilizes a fluidized bed carbochlorination process of the zircon ore in which uranium chloride is volatilized at the ore chlorinator temperature and follows as an impurity in the zirconium-hafnium tetrachloride stream, and in which removal of iron impurities is performed by liquid-liquid iron extraction with methyl isobutyl ketone, and the zirconium-hafnium stream is further processed by a separations step to reduce the hafnium content to low levels by liquid-liquid hafnium extraction. The improvement comprises adding 1-9 weight percent quaternary ammonium halide (e.g. tricaprylmethylammonium chloride) to the methyl isobutyl ketone in the liquid-liquid iron extraction.

Abstract: In the production of a highly pure hafnium oxide by calcination of a highly pure hafnium hydroxide, the production of a highly pure hafnium hydroxide from a hafnium-loaded, methyl isobutyl ketone solvent that is substantially free of zirconium and sulfate ions by adding ammonia to such solvent to produce a three-layered reaction product having MIBK solvent on top, ammonium thiocyanate solution in the middle, and a highly pure hafnium hydroxcide sludge at the bottom which is separately removed, freed of water, and calcined.

Abstract: Chelating agents on which metals such as uranium have been adsorbed are brought into contact with an eluent of aqueous solution containing reducing agents and basic compounds, until the metals are eluted. The elution is effected with large speed without degradation of the chelating agents. Preferred chelating agents are rather stable under basic conditions but not under acidic conditions, for example, those having .dbd.NOH group in their molecules. The reducing agents and basic compounds in the eluent are, for example, sulfurous acid or salts thereof and sodium hydroxide, respectively.

Abstract: Disclosed herein is a high-dispersion sol of monoclinic zirconia supermicrocrystals which is translucent and contains monoclinic zirconia supermicrocrystals of uniform size and a rodlike shape or ellipsoidal shape having a diameter or width smaller than 100 .ANG., at a concentration higher than 0.1 mol/liter. The sol is produced by preparing a clear or sherbetlike mixture of water and zirconyl chloride or an aqueous solution of a zirconium salt of hydroxide and hydrochloric acid, subjecting the mixture or the aqueous solution to hydrothermal treatment in a sealed container at more than 130.degree. C. for more than 24 hours, to give a white pasty product, diluting the pasty product with water so that the concentration decreases below 1 mol/liter as zirconium, adjusting the pH to 3 to 7, and finally concentrating the diluted product.

Abstract: Method for reduction in metallic impurities in aqueous and anhydrous TiCl.sub.4. The method utilizes activated carbon to remove poisonous impurities such as antimony and arsenic, which allows use of the TiCl.sub.4 in pearlescent pigment production and cosmetics.

Abstract: The zirconium 91 isotope is separated from zirconium by a photo-assisted extraction process wherein a first solution is formed of a first solvent, scavenger and zirconium compound, which compound reacts with the scavenger when exposed to light, and while irradiating the first solution to form a zirconium reaction product, contacting the same with a second solvent that is immiscible with the first solvent and is a preferential solvent for the zirconium reaction product, with the reaction product transferred to the second solution, and the two solutions then separated. An acidic aqueous media is preferred as the first solvent, with excess acid used to provide anions that act as the scavenger.

Abstract: Process for preventing the extraction of technetium and/or rhenium, particularly during the extraction of uranium and/or plutonium by an organic solvent.This process permitting the extraction of a chemical element, such as uranium or plutonium present in an aqueous solution containing both said element, technetium and/or rhenium and zirconium and/or hafnium consists of contacting the aqueous solution with an organic solvent able to extract said element, wherein for preventing the extraction of the technetium and/or rhenium with said element, to the aqueous solution is added a zirconium and/or hafnium complexing agent in a quantity adequate for complexing all the zirconium and/or hafnium, said agent being soluble in the aqueous solution.

Abstract: A process for the purification by selective separation of uranium and/or molybdenum from zirconium and/or hafnium among other impurities contained in an amino organic phase by bringing them together with an aqueous sulphuric re-extraction solution, characterized in that, with a view to increasing the separation factor of the zirconium and/or hafnium on the one hand and the uranium and/or molbydenum on the other hand, the aqueous sulphuric re-extraction solution contains at least one alkali or equivalent sulphate.

Abstract: A process for the recovery of a heavy metal which comprises:bringing a polymer having pendant groups of the formula:--CO--NH--NH--CO--COOMin which M is hydrogen, sodium or potassium, into contact with an aqueous solution containing a heavy metal to have the heavy metal adsorbed by said polymer;andhaving said heavy metal desorbed from the said polymer.

Abstract: A solvent extraction-exchange process for the enrichment of either the zirconium 90 isotope component or the zirconium 91-96 isotope component of an aqueous feed stream containing both components is described. An aqueous feed stream of zirconium complexes such as that from a thiocyanate separation process is contacted with an organic solvent to preferentially extract one of the isotope components, resulting in an aqueous raffinate enriched in the other isotope component. The organic phase is further contacted with an aqueous phase enriched in said one isotope component to exchange the other isotope component from the organic phase with the one isotope component in the aqueous phase and produce a further enriched organic phase. The one isotope component in the further enriched organic phase is then stripped with an aqueous acidic strip medium, and zirconium enriched in said one isotope component separated therefrom.

Abstract: New compounds have been prepared from dicyclopentadiene bis(methylamine) which have the following formula ##STR1## wherein substituents A, B, X and Y each are independently selected from radicals including hydrogen, hydroxyalkyl (wherein the alkyl group contains 2-6 carbon atoms) phosphonic, sulfonic, hydroxyethyl- and hydroxypropylsulfonic, methylenephosphonic methylene-, ethylene- and propylenesulfonic, alkylcarboxylic acid radicals (having 2-4 carbon atoms) and the alkali or alkaline earth metal, ammonia and amine salts of any of the phosphonic, sulfonic or carboxylic acid derivatives. At least one of the substituents must be other than a hydrogen. These compounds are useful chelating agents and those containing the methylenephosphonic substituents are good threshold agents.

Abstract: In the manufacture of nuclear fuel tubes spent etching solutions containing nitric acid, zirconium, and hydrofluoric acid are produced as waste. A serial treatment process is employed to recover the zirconium and to restore the solution to the desired acid concentration. These processes include solvent extraction for zirconium removal and aqueous removal using evaporation or distillation.

Abstract: Acidic aqueous phases comprising sulfate ion and particularly sulfuric acid values, titanium ion and particularly titanium (IV) values, and iron ion, particularly iron (II) values, and advantageously waste streams emanating from a sulfate process for the production of TiO.sub.2, are extracted with an initial organic phase which comprises at least one neutral organic extractant having the general formula: ##STR1## in which A and B, which may be the same or different, are the groups R.sub.1 or OR.sub.2, wherein R.sub.1 and R.sub.2 are straight or branched chain alkyl, alkenyl, alkynyl, alkoxyalkyl, aryl or alkylaryl radicals, or halogen substituted such radicals; and R is either R.sub.1 or R.sub.2 as above-defined, with R, R.sub.1 and R.sub.

Abstract: A process for separating inorganic substances involving their abstraction from a mixture with near-supercritical inorganic fluids. One or more inorganic substances are abstracted and then separatively recovered by retrograde condensations. The process particularly is applicable with mixtures obtained from the chlorination of metalliferous ores and may be conjoined to many ancillary metal abstraction processes such as volatilizations, distillations or electrolyses.

Abstract: Zirconium- and uranium-containing hydrocarbon-amine solutions are treated for separation of zirconium and uranium by means of a process comprising: (1) selective stripping of zirconium with an aqueous chloride solution, and (2) scrubbing the resulting aqueous solution with chloride-loaded hydrocarbon-amine solution to selectively remove uranium, thereby yielding an aqueous zirconium solution of low uranium content.

Abstract: Nuclear fuel processing solution consisting of tri-n-butyl phosphate and dodecane, with a complex of uranium, plutonium, or zirconium and with a solvent degradation product such as di-n-butyl phosphate therein, is contacted with an aqueous solution of a salt formed from hydrazine and either a dicarboxylic acid or a hydroxycarboxylic acid, thereby removing the aforesaid complex from the processing solution.

Abstract: Metal values, such as iron, may be stripped from an organic liquid medium loaded with metal ions by a process which comprises contacting the organic medium with an aqueous phase at a contact temperature which is sufficiently high to cause the metal values to precipitate as metal oxide, hydroxide or hydrate (or a mixture thereof) in the presence of the organic medium.

Abstract: Titanium metal values may be recovered from a titanium bearing source such as an ilmenite ore by subjecting the source to a reductive roast and leaching the reduced source with a halogen containing compound such as hydrochloric acid. The soluble titanium halide is then extracted from the leach liquor by utilizing an organophosphoric acid such as mono-2-ethylhexylphosphoric acid. The extracted titanium may then be stripped from the loaded organic acid solution by treating the solution with a mixture of hydrogen peroxide and an inorganic acid. Thereafter the desired titanium metal value may be recovered from the acid solution by any means known in the art such as hydrolysis.

Abstract: The invention described herein relates to a method for improving the acid leachability of aluminum and other metal values found in fly ash which comprises sintering the fly ash, prior to acid leaching, with a calcium sulfate-containing composition at a temperature at which the calcium sulfate is retained in said composition during sintering and for a time sufficient to quantitatively convert the aluminum in said fly ash into an acid-leachable form.

Abstract: There is disclosed, in a process for separating zirconium and hafnium, an improvement for the removal of sodium sulfate from a sulfate-containing sodium chloride solution. This improvement includes adding a water-miscible organic precipitant such as methanol, ethanol or acetone to the sulfate-containing sodium chloride solution. The precipitant is added in an amount sufficient to cause the removal of sulfate as sodium sulfate. The organic precipitant is removed and the substantially sulfate ion free sodium chloride solution is recycled. Also provided is a process for the recovery of sodium sulfate having a purity greater than 99.9%.

Abstract: Separation of zirconium and hafnium by solvent extraction with a tertiary amine from sulfuric acid solution is improved by addition of water-soluble .alpha.-hydroxycarboxylic acid to the aqueous phase.

Abstract: A method of essentially preventing the formation of 3-mercapto-4-methyl-2-pentanone by selectively controlling an ammonium thiocyanate-methyl isobutyl ketone regeneration system by maintaining the pH in the range of 4 to 9, and the temperature below 150.degree. F.

Abstract: A process for recovery of zirconium from pickling solutions which have been used to treat products formed of zirconium or zirconium-based alloys, the invention particularly provides for separating zirconium from the acids contained in such solutions. The present process comprises passing the used or spent pickling solutions which contain from 1 to 50 g/l of dissolved zirconium through a column of an anionic ion-exchange resin by means of which the zirconium ions are separated from fluoride and nitrate ions originally present in the pickling solutions. Approximately 90% of the zirconium contained in such solutions can be recovered according to the invention, it being further possible to recycle residual fluoride and nitrate ions which remain in the used pickling solutions.

Abstract: An improved process is described for producing titanium dioxide from ilmenite-type ore. The ore is digested with aqueous hydrogen fluoride, the resulting liquid mixture treated with a water-soluble oxidizing agent, and the ferric iron impurities, in the resulting digestion solution, at a pH between about 1.0 and 6.0, are extracted out with a mono-or dialkyl, or mono- or di-(alkylphenyl) orthophosphoric acid, such as di-(2-ethylhexyl) orthophosphoric acid. The remaining solution is treated with ammonium hydroxide to precipitate hydrated titanium dioxide which is then calcined to form pigmentary titanium dioxide. Alkali metal and ammonium salts of the organophosphoric acid are also useful in the process.

Abstract: Production of titanium dioxide which is characterized by recovery of reusable H.sub.2 SO.sub.4, highly pure Fe oxide and hydroxide and fractional recovery of Mn, V and Cr, etc., from FeSO.sub.4. nH.sub.2 O and waste acid of 20 - 40% H.sub.2 SO.sub.4 containing abundant heavy metallic ions, which are by-produced in the production of TiO.sub.2 by dissolution of Ti raw materials such as ilmenite, steel production slag, such as electric furnace slag, convertor slag with H.sub.2 SO.sub.4.

Abstract: In this process metal ions such as Ag.sup.+, Pb.sup.2+, Co.sup.2+, Cu.sup. 2+, Fe.sup.3+, etc., are extracted through a porous membrane impregnated with the first extractant containing chelating agents. The membrane contacts with an extraction feed on one side, and with the second extractant on the other side, and the objective metal ions are transferred from the feed to the second extractant. Throughout the extraction process, the pH values of the extraction feed, the impregnated extractant solution, and the second extractant are kept in decreasing order.An apparatus used for the above objective is also provided by this invention.

Abstract: A process for making titanium nitride powder by reaction of titanium phosphates with sodium cyanide.