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Invention relates to petrochemical industry and can be used in production of neodymium 1.4-cis-polysoprene. Method of obtaining solvate of neodymium chloride with isopropyl alcohol for neodymium catalyst of isoprene polymerisation is realised by mixing neodymium chloride with isopropyl alcohol, with performance of hydrodynamic impact in tubular turbulent reactor of diffusor-confusor construction at the stage of synthesis of neodymium chloride solvate. |
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Method of extracting rare-earth metals (rem) from phosphogypsum Proposed method comprises REM sulphuric acid leaching from gypsum pulp with application of ultrasound oscillations, separation of said pulp to REM productive solution and cake, precipitation of REM collective concentrate from productive solution with production of water phase. Pulp is prepared on the basis of sulphuric acid solutions processed by electrochemical activation. Note here REM leaching is conducted under conditions of pulp circulation at combined effects of ultrasound oscillations at cavitation and magnetisation. Leaching pulp is divided into REM productive solution and first cake. REM are precipitated from productive solution as REM oxalates with production of REM collective concentrate. Water phase after precipitation of oxalates is divided into to parts. One part is re-restored by sulphuric acid and subjected to electrochemical activation for use in circulation while another part is neutralised to get the second cake to be flushed combined with first cake and directed for gypsum production. |
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Method of extracting rare earth elements from extraction phosphoric acid Invention relates to a method of extracting a concentrate of rare earth elements (REE) from extraction phosphoric acid. Extraction phosphoric acid with the concentration of 27-45 wt %, which contains REE and thorium, is passed through sulphoxy cationite with formation of a REE-depleted thorium-containing phosphate solution and cationite, saturated with REE. In the process of passing phosphoric acid through sulphixy cationite thorium concentration in the REE-depleted phosphate solution, which twice becomes equal to its concentration in initial phosphoric acid, is fixed. When the concentration of thorium in the REE-depleted solution for the second time becomes equal to its concentration in initial phosphoric acid, cationite is considered to be REE-saturated and passing of phosphoric acid through it is stopped. Saturated cationite is washed with water. Then desorption of REE by a solution of ammonium sulphate or nitrate with the concentration of 275-300 g/l is carried out and from the obtained desorbate a non-radioactive REE concentrate is performed. |
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Method of extracting rare-earth elements from hydrate-phosphate residues from apatite processing Invention relates to a method of extracting rare-earth elements from nitrate-phosphate solutions from apatite processing. The method comprises dissolving apatite in nitric acid, freezing out calcium (strontium) nitrate, precipitating hydrate-phosphates of rare-earth elements and calcium (strontium), dissolving the precipitate in nitric acid, adding calcium (strontium) nitrate obtained from the freezing out step with concentration of 800-1000 g/l and heated to 40-50°C to the solution, wherein content of rare-earth elements (in terms of oxides) is kept at 40-60 g/l, and excess nitric acid 1-2 mol/l, followed by extraction of rare-earth elements with tributyl phosphate in the presence of calcium nitrate, washing and re-extraction, wherein the extract is washed with evaporated re-extraction product to rare-earth element concentration of 250-300 g/l. 70-90% of the obtained solution is removed in form of a finished product and the remaining solution is taken for washing, wherein the raffinate, which contains calcium nitrates and iron and aluminium impurities, is taken for recovering calcium (strontium) nitrate by freezing out or precipitating impurities with calcium oxide. |
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Method of purifying phosphate-fluoride concentrate of ree Invention relates to purification of a phosphate-fluoride concentrate of rare earth elements (REE), obtained in the complex apatite processing. A method of purification of the phosphate-fluoride concentrate of REE, which contains admixtures of calcium and thorium, includes processing of the concentrate with a solution of sulphuric acid with a concentration of 4-6 wt % in the presence of sulphoxide cationite. REE, admixtures of thorium and calcium are absorbed by sulphoxide cationite, transfer of fluorine together with phosphorus into the sulphuric acid solution, separation of the sulphuric acid solution from sulphoxide cationite, desorption from cationite of REE and admixtures of thorium and calcium with an ammonium salt solution with obtaining desorbate and its neutralisation with an ammonium compound in three stages. At the first stage neutralisation is carried out until pH 4.2-5.0 is achieved with formation and separation of a thorium-containing residue, at the second stage - until pH 7.0-7.5 is achieved with formation and separation of a concentrate of REE, and at the third stage - until pH not less than 8.5 is achieved with formation and separation of a calcium-containing residue. |
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Invention relates to composition, based on oxides of zirconium, cerium and at least one rare earth metal element, different from cerium, to method of its obtaining and to its application for purification of exhaust gases of internal combustion engines. Composition, based on oxides of zirconium, cerium and at least one rare earth metal element, different from cerium, contains cerium oxide not more than 50 wt % and has after burning at 1000°C for 6 hours maximal temperature of reductability not more than 500°C and specific surface at least 45 m2/g. method of obtaining composition includes carrying out continuous reaction in mixture of compounds of zirconium, cerium and other rare earth metal element, different from cerium with basic compound with time of being in reactor not longer than 100 milliseconds, obtained sediment is heated, and then combined with surface-active substance before burning Catalytic system, containing claimed composition, and method of purification of exhaust gases of internal combustion engines with application of described above composition or catalytic system as catalyst, are described. |
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Method of separating gadolinium by extraction with phosphoroorganic compounds Invention can be used in chemical industry. At the first stage of gadolinium extraction terbium, dysprosium and heavier REM are extracted from mixture of rare earth metals in organic phase. At the second stage gadolinium is extracted from obtained raffinate solution in organic phase, with main mass if europium, samarium, neodymium and other lighter REM left in water phase. gadolinium is extracted into re-extract from obtained organic phase, with all gadolinium-containing re-extract being returned to stage of washing, and the process is carried out until required content of samarium and europium in gadolinium is achieved, obtained gadolinium solution is output and the process is repeated. As extractant used are 30-40% solutions of di-2-ethylhexylphosphoric acid or bis((2,4,4)trimethylpentylphosphinic acid (Cyanex-272), or isododecylphosphetanic acid. |
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Invention relates to a novel inorganic green pigment for dyeing different materials. The pigment has the formula RE2MoO6, where RE denotes mixed rare-earth metals in amount of 66.66 mol %, Mo denotes molybdenum in amount of 33.34 mol %. The mixed rare-earth metals are a mixture of rare-earth elements with atomic number from 57 to 66. The metals include at least 43-45 wt % lanthanum, 33-35 wt % neodymium, 9-10 wt % praseodymium, 4-5 wt % samarium and other rare-earth elements selected from cerium, dysprosium, gadolinium, europium, terbium and yttrium in amount of 5 wt %. The pigment is obtained by mixing solid phases of a carbonate of said mixture of rare-earth elements and ammonium heptamolybdate, calcining the mixture at 900-1100°C for 3-6 hours while heating at a rate of 10°C/min, followed by grinding. |
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Luminescent method of determining samarium Invention relates to analytical chemistry and specifically to a method for luminescent determination of samarium. The method involves converting samarium into a luminescent compound with an organic reagent. The organic reagent used is diphenyl ether of sulphosalicylic acid and a cationic surfactant - cetylpyridinium bromide is added, with the following ratio of components: Sm: diphenyl ether of sulphosalicylic:surfactant=1:2:14 at pH=6.4. |
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Method of photometric determination of rare earth elements Invention relates to analytical chemistry, namely to photometric methods of determining rare earth elements in natural objects and technical materials. method includes decomposition of sample by its melting with mixture of anhydrous soda and borax, processing decomposed sample with hydrochloric acid, precipitation of metal hydroxides, washing residue of metal hydroxides with ammonium hydroxide, elimination interfering impact of titanium compounds by addition of hydrogen peroxide before precipitation of hydroxides, elimination of interfering impact of iron and aluminium by masking iron by addition of ascorbic acid and masking aluminium by addition of sulfosalicylic acid, conversion of non-soluble compounds of rare earth elements into soluble compounds, transfer of rare earth elements into dyed compounds with arsenazo III and further photometry. |
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Electrolytic method for obtaining ultrafine powder of dysprosium hexaboride Invention relates to electrolytic methods for obtaining pure dysprosium hexaboride. Anhydrous dysprosium trichloride is used as dysprosium source, potassium fluoroborate is used as boron source, and equimolar mixture of potassium and sodium chlorides is used as base electrolyte. Electrolysis is carried out in potentiostatic mode at temperature of 700±10°C, current densities of 0.1 to 1.0 A/cm2 and electrolysis potentials of 2.5 to 2.8 V relative to glass-carbon quasi-stationary comparison electrode. |
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Method of producing nanopowder zirconium, yttrium and titanium composite oxide Invention can be used in production of dense wear-resistant ceramic and solid electrolytes. The method of producing powder of a zirconium, yttrium and titanium composite oxide involves preparing a starting solution of nitrates, adding an organic acid and a titanium-containing compound into said solution, followed by heat treatment. The organic acid used is glycine in amount of 1.6-2.5 mol per 1 g-atom of the sum of metal cations (Zr+4+Ti+4+Y+3). The titanium-containing compound used is a hydrolysable titanium compound with the ratio Zr+4:Ti+4=(0.99-0.85):(0.15-0.01). The starting solution is further mixed with 30% hydrogen peroxide with the ratio H2O2:Ti+4=(4.7-12):1. The hydrolysable titanium compound used can be titanium tetrabutylate or titanium sulphate or titanium tetrachloride. |
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Method of extracting rare-earth elements from phosphogypsum Invention can be used in chemical industry to extract rare-earth elements from phosphogypsum. The method involves carbonising phosphogypsum to obtain phosphochalk, dissolving said phosphochalk in nitric acid to obtain a product suspension and then separating the insoluble residue - a black concentrate of rare-earth elements - by filtering. The product suspension is divided into two parts, one of which is fed for filtration to separate the insoluble residue - black concentrate, and the second is fed for premixing with nitric acid. The mixing process is carried out for 3-5 minutes with the ratio CaO/HNO3 equal to 0.75-2.25. When dissolving, pH is kept at 2.2-4. |
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Invention relates to a composition based on cerium oxide and zirconium oxide having special porosity, which can be used in catalyst systems for treating exhaust gases. The composition is based on cerium oxide and zirconium oxide containing at least 30 wt % cerium oxide which, after calcination at temperature of 900°C for 4 hours, has two types of pore distribution, the diameters of which, for the first type of distribution, lie in the range from 5 nm to 15 nm for a composition having cerium oxide content of 30% to 65%, or from 10 nm to 20 nm for a composition having cerium oxide content higher than 65% and, for the second type of distribution, in the range from 45 nm to 65 nm for a composition having a cerium oxide content of 30% to 65% or from 60 nm to 100 nm for a composition having cerium oxide content higher than 65%. The method of producing the composition includes steps of: forming a first liquid medium containing a zirconium compound, a cerium (III) compound, sulphate ions, an oxidising agent and, optimally, a compound of a rare-earth element other than cerium; bringing the medium into contact with a base, whereby a precipitate is formed; separating and washing the precipitate; suspending the precipitate in water and heat treatment of the obtained medium at temperature of 90°C; and separating and calcining the precipitate. |
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Method of extracting rare-earth elements from wet-process phosphoric acid Invention relates to methods of extracting a concentrate of rare-earth elements from wet-process phosphoric acid, which is obtained in a dihydrate process of treating an apatite concentrate, and can be used in industry. Wet-process phosphoric acid heated to 65-80°C, which contains rare-earth elements and fluorine, aluminium, titanium and iron impurities, is mixed with ammonia in an amount which ensures the molar ratio NH3:P2O5=(0.2-1.0):1. Ammonium fluoride is then added to the acid in amount of 20-30 g/l to obtain a suspension and transfer the main part of rare-earth elements and part of the impurity components into the precipitate. The precipitate of the rare-earth element concentrate is separated from the phosphoric acid solution. |
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Electrolytic method of producing ultrafine gadolinium hexaboride powder Powder is synthesised by electrolysis from a molten medium which includes gadolinium chloride and calcium fluoroborate in a background electrolyte at temperature of 550±10°C in an atmosphere of purified and dried argon. The background electrolyte used is a eutectic mixture of potassium, sodium and caesium chlorides, with the following ratio of components, wt %: gadolinium chloride 3.0-7.0, potassium fluoroborate - 6.0-10.0, eutectic mixture of potassium, sodium and caesium chlorides - the balance. |
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Catalysts of oxidation for diesel engines based on base metals and modified with base metals Inventions can be used in field of environment protection. Method of catalyst obtaining includes introduction of base metal in form of ammonium hydroxide or ammonia complex, or in form of organic amine complex, or in form of hydroxide compound into active in redox reactions cubic fluorite CeZrOx material under basic conditions. Catalyst of oxidation includes primary catalytic active metal from group of noble metals, applied on carrier, as well as secondary catalytic active component, which is obtained by ionic exchange between surface of cubic fluorite CeZrOx material and base metal solution and optionally zeolite. Obtained catalysts are used in catalytic device, placing one of them on substrate, around which case is located. Obtained catalysts are also used in method of processing of exhaust gases, passing exhaust gases above them. |
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Luminescent method of determining terbium Invention relates to analytical chemistry and specifically to a method for luminescent determination of terbium. The method involves converting terbium into a luminescent compound with an organic reagent. The reagent used is 1,2-dioxybenzene-3,5-disulphonic acid (DBSA) and ethylenediaminetetraacetic acid (EDTA) is added to the solution of the luminescent complex of terbium with DBSA in ratio Tb:DBSA:EDTA=1:1:1 at pH=12.0-13.0. |
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Method of obtaining mesoporous nanosized cerium dioxide powder (versions) Invention relates to chemical industry, to production of nanosized powders of metal oxides for fine-grained ceramics of broad spectrum. Method of obtaining cerium dioxide powder includes stages: obtaining water 0.05M solution of cerium nitrate or cerium acetate, using Ce(NO3)3·6H2O or Ce(CH3COO)3·H2O, obtaining alcohol solution of stabiliser of sol of organic N-containing compound: N,N-dimethyloctylamine, tetraethylammonium hydroxide or monoethanolamine with concentration 0.45-3.30M, 0.37M and 0.016M, obtaining sol in water-organic system by combination of composed solutions, evaporation of water-organic system, formation of gel and thermal processing of gel in the interval of temperatures 95-500°C by step-by-step schedule, with application as sol stabilser of one of the following low-molecular organic N-containing compounds (N): N,N-dimethyloctylamine, tetraethylammonium hydroxide or monoethanolamine in form of alcohol solution with molar ratio N/metal, equal 1-20. |
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Method of obtaining calcium-doped lanthanum manganite Calcium-doped lanthanum manganite is obtained by reaction from lanthanum, manganese and calcium oxides by their grinding, first annealing in air at 1350±50°C, cooling to room temperature, re-grinding and pressing obtained material in tablets, its re-annealing in air at 1350±50°C, further annealing in oxygen and cooling to room temperature, with obtaining samples with composition La1-xCaxMn1-zO3, in which selected calcium concentration is 0.05<x<0.22, selected manganese concentration is 0<z≤0.05, first annealing in air is carried out for 12 hours, second re-annealing in air is carried out for 4 hours, annealing in oxygen is carried out at T=650±20°C for 50 hours, and further cooling to room temperature is carried out in air at rate not lower than 10°C/min. |
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Method of processing phosphogypsum Method of processing phosphogypsum involves step-by-step agitation sulphuric-acid leaching of rare-earth metals and phosphorus while feeding sulphuric acid to the head step, using the obtained leaching solution of the head step at subsequent leaching steps, separating the undissolved residue from pulp of a tail step and washing with water, treating the leaching solution of the tail step to obtain a mother solution, using the mother solution and the washing solution for leaching. Leaching of the rare-earth metals and phosphorus at the second and subsequent steps is carried out from a mixture of phosphogypsum and the leached pulp from the previous step. Sulphuric acid is fed to the head leaching step in an amount which enables to extract rare-earth metals and phosphorus into the solution at the head step and subsequent steps at pH values at the tail leaching step not higher than pH at the onset of precipitation of rare-earth metal phosphates. The tail step for leaching rare-earth metals and phosphorus is carried out while simultaneously treating the leaching solution by extracting rare-earth metals by sorption with a cationite. The rare-earth metal-saturated cationite is separated from the mother pulp and taken for producing a rare-earth metal concentrate. A portion of the mother solution is pre-purified from phosphorus by precipitation thereof with a basic calcium compound. The obtained phosphorus-containing precipitate is fed for recycling. |
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Method of obtaining complex yttrium, barium and copper oxide Invention can be applied in microelectronics. To obtaining complex yttrium, barium and copper oxide YBa2Cu3O7-δ, from water solution, which contains yttrium, barium and copper nitrates, combined sorption of yttrium, barium, copper in given molar ratio Y:Ba:Cu = 1:2:3 is carried out at the stage of sorption from the said solution on carboxyl cationite KB-4p-2. After that, obtained material is dried and subjected to successive heating at temperature 110 - for 2 h, at 250°C - for 2 h, at 450°C - for 5 h, at 600°C - for 3 h, at 850°C - for 6 h and after that for 1 hour in oxygen atmosphere. |
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Method of obtaining stabilised water sol of nanocrystalline cerium dioxide, doped with gadolinium Invention relates to technologies of nanomaterials production for obtaining of oxide fuel elements, thin coatings, films, which have high ionic conductivity. Method includes preparation of water solution of cerium and gadolinium salts, in which total concentration of rare earth elements constitutes 0.005÷0.02 mole per litre of water, and molar ratio of Ce:Gd constitutes from 19:1 to 4:1, addition of anion-exchange resin in OH-form to obtained solution until pH 9.0÷10.0 is reached, separation of formed colloidal solution from anion-exchange resin by filtering, hydrothermal processing at 120÷210°C for 1.5÷4 h and cooling to room temperature. Obtained unstable sol of nanocrystalline cerium dioxide, doped with gadolinium, is additionally stabilised with salt of polybasic acid (citric or polyacrylic) with molar ratio of rare earth elements in acid, equal 1:1÷4, and following slow drop-by-drop addition of ammonia water solution until pH 7÷8 is obtained. |
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Complex processing of coal combustion flue ash Invention relates to processing of wastes, particularly, to ash-and-slag wastes of thermal electric power stations. Coal combustion ash is placed in reaction zone to add carbon sorbent thereto in amount of 10-25 kg per ton of ash. Then, it is processed by the mix of ammonium fluoride and sulfuric acid, heated to 120-125°C and held thereat for 30-40 minutes. Tetrafluorosilane resulted from said processing is absorbed by ammonium fluoride. Solution of ammonium hydroxide is introduced into that of ammonium tetrafluorosilicate to precipitation of silicon dioxide. Then, concentrated sulfuric acid in double surplus is added to aluminium residue, held at 250°C for 1.5 h and processed by water. Solid residue is calcined at 800°C. |
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Method of production of rare-earth element fluorosulphide powders Invention relates to inorganic chemistry, particularly to production of powders to be used in laser technology and optical instrument making. Proposed method comprises preparation of blend and its thermal treatment. Said blend is prepared from the powder of sesquialteral rare-earth element sulphides with particle size of 1-30 mcm and powder of rare-earth element trifluorides with particle size of 10-70 nm at molar ratio of 1:1.Thermal treatment of the blend is conducted at 650-800 °C for 20-30 minutes in atmosphere of argon, sulfiding gases H2S+CS2 and fluoridiser gases C2F4, CF4 obtained in Teflon pyrolysis. |
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Method of obtaining complex scandium chloride and alkali metal Invention relates to inorganic chemistry and deals with method of obtaining complex scandium chloride and alkali metal. Metallic scandium is mixed with lead dichloride and salt of alkali metal. Obtained charge is placed into crucible with inert atmosphere, heated to reaction temperature in presence of metallic lead and kept at temperature, exceeding melting temperature of mixture of salts by 50-100°, for 10-30 minutes. Metallic scandium is applied in compact form in from of pieces. As salt of alkali metal, metals chlorides are applied. In initial charge mixture of chloride salts of alkali metals is applied. |
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Invention relates to inorganic chemistry and specifically to a method of producing powder of solid solutions of rare-earth oxysulphides for making ceramic articles, phosphors and laser materials. The method of producing powder of solid solutions of lanthanum, neodymium, praseodymium and samarium oxysulphides involves preparing a mixture of given mass of weighted forms of rare-earth oxides dissolved in nitric acid, precipitating rare-earth sulphates from the obtained solution using concentrated sulphuric acid, evaporating the formed suspension on air at 70 - 90°C to a dry state, grinding and calcining at 600°C for 1.5 hours, further grinding to a fine state and treating in a hydrogen stream with gas feed rate of 6 eq/h with respect to the weight of rare-earth sulphates at the following temperatures and duration of heat treatment: 600°C - 10 hours, 700°C - 5 hours and 850°C - 1 hour. |
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Molybdate-based inorganic pigment Invention can be used in paint-and-varnish industry, in making plastic, ceramics and construction materials. The molybdate-based pigment, which contains cerium and an alkali-earth metal, is a complex molybdate with a scheelite structure of the composition Ca1-3/2XCexMoO4, where 0.10≥x≥0.02. |
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Method for synthesis of cuprates of barium and rare-earth elements Invention can be used in chemical industry. The method involves calcining a heteropolynuclear complex of nitrates of rare-earth elements, copper (II), barium and quinoline, after preliminary calcining, cooling and homogenisation. Basic calcining is carried out at temperature of 850°C for the yttrium subgroup, and at 750°C for the cerium subgroup. |
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Synthesis of cerium oxide nanoparticles in supercritical water Invention can be used in chemical industry. Cerium oxide CeO2 nanoparticles are obtained by mixing 0.2 M Ce(NO3)3 · 6H2O solution with supercritical water. The reaction is carried out at temperature of 370-390°C and pressure of 240-260 atm. The ratio of the volume of the cerium salt solution to the volume of supercritical water is preferably equal to 2:10. |
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Method of extracting rare-earth metals from phosphogypsum Invention can be used in chemical industry and production of construction materials. Proposed method comprises processing phosphogypsum by sulfuric solution, filtration, extraction of precipitate of rare-earth metal insoluble compounds and separation of precipitate by filtration. Rare-earth metals are extracted from solution by oxalic acid or its soluble salts at consumption of 250-300 mol % while solution is neutralised to pH=1.0-2.5. Obtained precipitate of oxalates is separated from mother solution, rinsed, dried and calcined. |
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Fuel additive containing cerium dioxide nanoparticles with altered structure Invention relates to a method of producing cerium dioxide nanoparticles and use thereof. Described is a method of producing cerium dioxide nanoparticles with a given lattice, which contain at least one transition metal (M), wherein: (a) an aqueous reaction mixture is prepared, said mixture containing a source of Ce3+ ions, a source of ions of one or more transition metals (M), a source of hydroxide ions, at least one nanoparticle stabiliser and an oxidant which oxidises the Ce3+ ion to a Ce4+ ion, at initial temperature ranging from about 20°C to about 95°C; (b) mechanical shearing of said mixture and passing said mixture through a perforated sieve to form a homogeneously distributed suspension of cerium hydroxide nanoparticles; and (c) creating temperature conditions that are effective for oxidation of the Ce3+ ion to a Ce4+ ion to form a product stream containing cerium dioxide nanoparticles, containing a transition metal Ce1-xMxO2, where x assumes a value from about 0.3 to about 0.8, said nanoparticles have a cubic fluorite structure, average hydrodynamic diameter ranging from about 1 nm to about 10 nm and geometric diameter from about 1 nm to about 4 nm, wherein the nanoparticle stabiliser is water-soluble and has a value Log KBC ranging from 1 to 14, where KBC denotes a constant for binding the nanoparticle stabiliser to a cerium ion in water and said temperature conditions that are effective for oxidation of the Ce3+ ion to a Ce4+ ion include temperature from about 50°C to about 100°C. Described is a method of preparing a homogeneous dispersion containing stabilised crystalline nanoparticles of cerium dioxide with a given lattice, containing a transition metal, Ce1-xMxO2, where M is at least one transition metal and x assumes a value from about 0.3 to about 0.8; (a) preparing an aqueous mixture which contains stabilised cerium dioxide nanoparticles containing a transition metal, Ce1-xMxO2, having a cubic fluorite structure, wherein, wherein said nanoparticles have average hydrodynamic diameter ranging from about 1 nm to about 10 nm and geometric diameter less than about 4 nm; (b) concentrating said aqueous mixture containing said stabilised cerium dioxide nanoparticles containing a transition metal, thereby forming an aqueous concentrate; (c) removing essentially all water from said aqueous concentrate to form an essentially water-free concentrate of stabilised cerium dioxide nanoparticles containing a transition metal; (d) adding an organic diluent to said essentially water-free concentrate to form an organic concentrate of said stabilised cerium dioxide nanoparticles containing a transition metal; and (e) merging said organic concentrate with a surfactant in the presence of a nonpolar medium to form said homogeneous dispersion containing stabilised crystalline nanoparticles of cerium dioxide containing a transition metal, Ce1-xMxO2, where M and x assume values given above. Described is a deposited coating for the catalytic converter of the exhaust system of an internal combustion engine, where said deposited coating is obtained using said homogeneous dispersion. |
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Method of processing phosphogypsum Method of processing phosphogypsum involves leaching phosphogypsum which contains rare-earth elements and impurities, including phosphorus, fluorine and sodium, by passing sulphuric acid solution with concentration of 3-6 wt % at liquid-to-solid ratio of 1.5-2.0 through a layer of phosphogypsum to transfer the rare-earth elements and impurity components into the leaching solution. The leaching solution is separated in form of two consecutive portions, the volume of the first portion being smaller. The first portion is neutralised with a calcium-containing reagent to pH 6-8 and the precipitate which contains impurity components is separated. The calcium-containing reagent used is slaked or unslaked lime. The second portion of the leaching solution is taken for sorption extraction of rare-earth elements using a sulphoxide cationite to obtain a lean sulphuric acid solution. After leaching, the phosphogypsum is washed with water in amount of 0.4-0.5 l per kg of phosphogypsum to obtain washed phosphogypsum and washing sulphuric acid solution. That solution is mixed with the lean sulphuric acid solution, fortified with strong acid and taken for leaching phosphogypsum. |
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Method of producing dieuropium oxide-diiodide eu2oi2 Invention relates to production of binary compounds, specifically europium (II) oxoiodides, which are used as components of luminescent materials and also a method of producing dieuropium oxide-diiodide Eu2OI2. Reagents are added to the starting europium iodide derivative, followed by heating the mixture, holding at high temperature and then cooling to room temperature; the starting europium iodide derivative used is a nanohydrate of europium (III) iodide, the reagent used is thiocarbamide and the weight ratio of the starting europium iodide derivative to the reagent is equal to (5.10-5.30):1; the mixture is heated at a rate of 8-12 deg/min to temperature of 270-320°C, followed by holding for 1-2 hours and further cooling to room temperature at a rate of 3-5 deg/min. |
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Invention relates to hydrometallurgical processing of mineral material, particularly scandium-containing "tailings" obtained during beneficiation of titanium-magnetite ore by wet magnetic separation. The method of extracting scandium is three-step sulphuric acid leaching of scandium, wherein at the first step, leaching is carried out with recycled solution after extraction of scandium at temperature of 30-50°C and solid to liquid ratio of 1:6-7 for 3-4 hours; the pulp is then divided into a solid phase and a liquid phase; at the second step, a portion of the solution obtained from the first step is returned to the solid phase and sulphuric acid is added to concentration of 340-360 g/l and sodium fluoride is added in amount of 20-25 kg fluorine/t solid; leaching is carried out at temperature of 95-98°C and solid to liquid ratio of 1:2.5-3 for 3-4 hours; further, at the third step, the pulp is diluted in solid to liquid ratio of 1:6.5-7.5; treatment is carried out at temperature of 95-98°C for 3-4 hours. |
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Method of extracting rare-earth metals from technological and productive solutions and pulps Method of extracting rare-earth metals from solutions containing iron (III) and aluminium comprises sorption of rare-earth metals on sorbent. Ampholyte with iminodiacetic functional groups is used as said sorbent. Sorption is carried out after preliminary neutralisation or acidification of solution to pH 4-5 by whatever alkaline or acid agent to add ampholyte in obtained pulp with separation of solid fraction. Sorption is conducted at ampholyte:pulp ratio of 1:50-1:150, phase contact time of 3-6 h and in the presence of reducing agent. |
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Method of treating rare-earth phosphate concentrate separated from apatite Invention relates to methods of separating deactivated rare-earth elements during nitric acid treatment of apatite concentrate from nitrate-phosphate solutions. The method of treating a rare-earth phosphate concentrate isolated from apatite involves decomposition of the rare-earth phosphate concentrate with nitric acid, treating the obtained solution with oxalic acid with precipitation of rare-earth oxalates in two steps, at the first step of precipitation of oxalates of thorium and rare-earth elements, 5-10% oxalic acid in stoichiometric amount is added to rare-earth elements present in the solution, and at the second step of precipitation of rare-earth oxalates, 110-115% oxalic acid in stoichiometric amount is added to rare-earth elements present in the initial solution, and the rare-earth oxalates are then calcined to rare-earth oxides. |
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Method of making scandium oxide from red slag Proposed method comprises multistep leaching of red slag by the mix of sodium carbonate and bicarbonate on forcing annealing furnace flue gases containing carbon dioxide there through to obtained solution. Then, three-step holding of said solution at increased temperatures is performed along with selective separation of precipitates after every said step. At first step, said solution is heated to temperature not exceeding 80°C for, at least, 1 hour. Thereafter, it is settled for, at least, two hours at natural cooling. At second step, said solution is boiled and mixed for, at least, two hours. At third step, said solution is evaporated to 50% of initial volume to add 46%-solution of sodium hydroxide to concentration of Na2Ocaustic of 1.5-2.0 kg/m3. Now, it is boiled for, at least, 2 hours and precipitate containing scandium oxide is settled for 10-16 hours at natural cooling. |
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Method of producing anhydrous yttrium thiocyanate complex Invention relates to coordination chemistry, specifically to preparation of initial reagents for syntheses without water molecules. The method of producing an anhydrous yttrium thiocyanate complex characterised by the chemical formula [Y(18-crown-6)(NCS)3], or [Y(18-crown-6)(NCS)3]-nSol, where Sol is a solvent molecule, involves reaction of a hexahydrate of yttrium thiocyanate Y(NCS)3·6H2O with a crown ether denoted 18-crown-6 in solvents selected from: acetonitrile, tetrahydrofuran, ethyl acetate, isopropanol, with molar ratio 18-crown-6:yttrium=1.0-2.0, the reaction being carried out in an air atmosphere at temperature of 15-30°C. |
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Method for europium (iii) from salt solutions Invention relates to hydrometallurgy, in particular, to the method for extraction of europium (III) from salt solutions by floating extraction. In process of floating extraction of europium (III) cations the organic phase is represented by isooctyl alcohol, and the collector of surfactants of anion type is sodium sodium dodecyl sulfate in the concentration corresponding reaction stoichiometry: Eu+3+3NaDS=Eu(DS)3+Na+, where Eu+3 - cation of europium (III), DS- - dodecyl sulfate-ion. At the same time the floating extraction is carried out at pH=7.5-8.5, and at the ratio of organic and water phases 1/20-1/40. |
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Method of extracting samarium (iii) cations Invention relates to extraction of substances with organic extractants from aqueous solutions, particularly a method of obtaining samarium (III) cations from impoverished or industrial material using a liquid extraction technique. The method of extracting samarium (III) cations involves liquid extraction using an extractant - isooctyl alcohol and an organic diluent in form of sodium dodecylsuphate in a concentration which corresponds to stoichiometry. Extraction is carried out at pH=3.0-6.0. |
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Method of producing scandium oxide Proposed method comprises dissolving scandium-bearing concentrate in sulfuric acid, removing acid-insoluble residue, and precipitating scandium in the presence of ammonium compounds. Then, precipitate is filtered, flushed, dried and calcined to obtain scandium oxide precipitate. With acid-insoluble residue removed, sulfuric acid concentration in filtrate is increased to 540-600 g/dm3, ammonium chloride is added to solution in amount of 26.7-53.5 g/dm3 at 50-70°C and held for one hour at mixing. Produced precipitate is flushed by ethanol at volume ratio of 1-10-11. |
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Luminescent coordination compounds of lanthanides for light-emitting diodes Invention relates to complexes of lanthanides and organic ligands which are luminescent in the visible spectrum and are used in electroluminescent devices, means of protecting security paper and documents from falsification etc. Disclosed are novel luminescent coordination compounds of lanthanides of formula: where Ln is Eu3+, Tb3+, Dy3+, Sm3+, Gd3+. |
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Electrolytic method for obtaining ultradisperse powder of lanthanum hexaboride Method for obtaining pure lanthanum hexaboride is implemented by combined electrodeposition of lanthanum and boron from chloride molten metal on the cathode and their further interaction at atomic level. The process is performed in three-electrode quartz cell, where a tungsten bar serves as a cathode; a glassy carbon bar sealed in pyrex glass serves as a comparison electrode; a glassy carbon melting pot serves as anode and at the same time as a container. Synthesis of ultradisperse powder of lanthanum hexaboride is performed by means of controlled potential electrolysis from equimole KCl-NaCl melt containing lanthanum trichloride and potassium fluoroborate in the environment of cleaned and dried argon at potentials of -2.0 to -2.6 V relative to glassy carbon comparison electrode at the temperature of 700±10°C. |
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Method of obtaining compounds of divalent lanthanides Invention relates to methods of obtaining novel compounds of divalent lanthanides Ln(II), namely to method of obtaining compounds LnCl2·0.5H2O·(0.04-0.07)Bui 4Al2O. Method of obtaining compounds of lanthanides LnCl2·0.5H2O·(0.04-0.07)Bui 4Al2O, where Ln=Sm or Ln=Yb lies in reduction of trivalent lanthanides Ln(III), with crystallohydrates YbCl3·6H2O and SmCb·6H2O being used as such, to divalent lanthanides Ln(II), on condition that molar ratio LnCl3·6H2O/Bui 3Al constitutes 1/50-70, and reaction takes place at atmospheric pressure, room temperature, in hexane, in nitrogen atmosphere. |
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Method of obtaining alcohol solvate of neodymium chloride Invention relates to method of obtaining alcohol solvate of neodymium chloride, which can be used as component for obtaining catalyst of polymerisation of diene hydrocarbons. Method includes mixing water neodymium chloride with monoatomic alcohol or mixture of monoatomic alcohols and with paraffinic or aromatic hydrocarbon or their mixture, inert with respect to organoaluminium compounds, with concentration of neodymium in obtained mixture 3.7-12.5 wt %. Water neodymium chloride is obtained by step-by step removal of crystallisation water from neodymium chloride hexahydrate by heating with mixing in vacuum, supplying nitrogen through the layer of dried product to the content of 3.0-3.5 mole of water per 1 mole of neodymium chloride at temperature from 70 to 105°C and further to content of water not more than 0.8 mole per 1 mole of neodymium chloride at temperature from 130 to 135°C. |
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Electrolytic method of obtaining ultrafine powder of gadolinium hexaboride Anhydrous gadolinium trichloride is used as gadolinium source, potassium fluoroborate is used as boron source, and equimolar mixture of potassium and sodium chlorides is used as base electrolyte. Electrolysis is carried out in potentiostatic mode at temperature of 700±10°C, current densities of - 0.1 to - 1.0 A/cm2 and electrolysis potential of - 2.6 to -2.8 V relative to glass-carbon quasi-stationary comparison electrode. |
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Method and device for recovery of powder gadolinium oxide wastes Invention relates to processing of wastes of various mixes, in particular, inorganic wastes, and may be used for recovery of powder gadolinium oxide wastes. Proposed method comprises extracting gadolinium oxide powder fro waste material and its cleaning of impurities. Note here that cleaning is performed by flotation in mixing the pump with disperse phase unless homogeneous pulp is produced. Then, tank with pulp is subjected to dynamic loading till compaction of settled powder of Gd2O3 to single-piece mass with dark layer of impurities on its surface. Then, flotation medium is removed to cut top dark layer from compacted precipitate to layer of clean gadolinium oxide colour. Then, residues of compacted piece are placed onto pan to be dried in air furnace to allow separating the fractions by sieving. Now, prior to reuse of recovered Gd2O3 powder, its quality is inspected by spectral analysis. |
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Electrolytic method of producing ultrafine cerium hexaboride powder Invention relates to electrolytic methods of producing pure cerium hexaboride. The cerium source used is 1-4 wt % anhydrous cerium chloride, the boron source is 1-3 wt % potassium fluoroborate and the background electrolyte is a eutectic mixture of potassium, sodium and cerium chlorides, which makes up the balance amount. Synthesis of ultrafine cerium hexaboride powder takes place via electrolysis from a eutectic melt of KCl-NaCl-CsCl, which contains cerium chloride and potassium fluoroborate. |
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Method of producing colloidal solutions of luminescent nanoplates of rare-earth oxides Solution of rare-earth salts is prepared, for example, nitrates of gadolinium, europium, terbium and ytterbium, in non-polar solvents - oleyl amine, oleic acid or compositions thereof with concentration of rare-earth elements of 0.05-0.1 mol/l. The solution is heated in an inert atmosphere of argon to 80-100°C and held at that temperature for 15-30 minutes. Diphenyl ether is then added in amount of 5-10 moles of ether per mole of rare-earth elements. The mixture is heated to 250-300°C and held for 1-2 hours. Excess polar solvent - acetone - is added to the obtained mixture. The coagulated nanoparticles are separated from the solution by centrifuging and the residue is redispersed in excess heptane. Colloidal solutions of luminescent nanoplates of rare-earth oxides with average diameter of 8-17 nm and thickness of 1-15 nm are obtained. |
Another patent 2513413.