Electrolytic method of producing ultrafine gadolinium hexaboride powder. RU patent 2507314.
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Electrolytic method of obtaining ultrafine powder of gadolinium hexaboride / 2466217 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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Electrolytic method of producing ultrafine cerium hexaboride powder / 2466090 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. |
 Procedure for production of high and nano dispersed powder of metals or alloys / 2423557Powders of metals and their alloys are produced by electrochemical dissolution of metal anodes. Powder is settled in volume of electrolyte of melted chlorides salts containing chemical compositions able to reduce ions of metals and to regenerate on cathode. The procedure is carried out in salt melt; anodes are made of d-metals or their alloys, for example: Ni, Fe, Cu, Re, Ti, Nb, Mo, W, Pt, Ag and others, steel 20, steel 12X18H10T, nichrome, BT-20 and others. Redox potential of melt is initially set more negative, than electrode potential of produced metal at 100-3000 mV. |
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Procedure for production of powders of metals and alloys by reduction out of cathode material / 2423556 Procedure consists in enclosing solid phase cathode material into metal net, in connection of solid phase cathode material in net with ion conducting medium and in cathode reduction. As cathode material there is used solid phase halogenide salts of produced metals of II, IV, V, VI and VIII group of periodic table or their mixture or mixture of their halogenide salts and their oxides. Lithium or its alloys is used as anode. Before enclosing into the net cathode material is shaped as an item of specified form. Cathode reduction is carried out at temperature above melting temperature of ion-conducting medium. |
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Procedure for production of powder of high-melting metal / 2401888 Procedure consists in electro-chemical reduction of salt of high melting metal in melt of electrolyte in electrolyser by mixing it in pressure tight inert atmosphere. Also, there is used electrolyser with an anode and cathode made of metal of produced powder. As electrolyte there is used an equimolar homogenous mixture of chlorides of alkali metals. Notably, reduction is performed under isothermal conditions at direct current with cathode density from 0.01 to 1.0 A/cm2; alkali metal soluble in electrolyte is extracted on the cathode, while salt of settled high melting metal is extracted on the anode; salt is reduced to metal powder of high melting metal by interaction with at least one of sub-ions of alkali metal. Metal produced in electrolyte is extracted, crushed and washed. |
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Procedure for production of powders of high-melting metals / 2397279 Invention refers to procedure of production of high-melting metal powders. The procedure consists in preparing homogenous mixture of halogenides of alkali and alkali-earth metals at temperature above 500°C, in continuous mixing and in successive introducing alkali or alkali-earth metal at amount sufficient for forming a thin uniform layer on surface of electrolytic melt and constituting (1-5)×10-2 cm3 of metal per 1 cm2 of electrolyte area. Further, halogenides of alkali and alkali-earth metals are electro-chemically reduced in electrolyte melt in pressure tight inert atmosphere of an electrolytic cell. Also electro-chemical reduction is performed under isothermal conditions with direct current feed of cathode density from 0.01 to 1.0 A/cm2. Metal of produced powder is used as a cathode and anode. Electrolyte is mixed by rotation of an anode. Nano-dimension metal powder of required metal is produced in volume of electrolyte. Upon cooling metal is extracted, crushed and washed. |
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Electrolytic method for synthesis of praseodymium hexaboride / 2393115 Invention relates to electrolytic methods for synthesis of inorganic compounds, particularly praseodymium compounds. Combined electrodeposition of praseodymium and boron from chloride complexes at the cathode and their subsequent reaction at the atomic level to form praseodymium boride takes place in an atmosphere of cleaned and dried argon from a molten equimolar mixture of potassium and sodium chlorides which contains praseodymium chloride and potassium fluoroborate. Temperature is kept above melting point of the molten equimolar mixture of potassium and sodium chlorides. The ratio of components in the molten mixture is as follows, in wt %: praseodymium 1.6-5.0, potassium fluoroborate - 4.0-11.0, equimolar mixture of potassium and sodium chlorides - the rest. Synthesis is carried out at current density of 0.1-1.0 A/cm2 and electrolysis potential relative the platinum reference electrode from -2.5 to -4.0 V. |
 Method of producing nanodispersed powder of tungsten carbide / 2372421Invention relates to electrochemical synthesis of tungsten compounds and can be used for producing nanodispersed pure powder of tungsten carbide, with developed surface and electrocatalytic properties. Electrolysis of a melt, containing, mol %: lithium tungstate 35.0 to 45.0, lithium carbonate 15.0 to 20.0, sodium tungstate - the rest, is carried out in open cells in galvanostatic mode with cathode current density ranging from 2.5 to 7.5 A/cm2. |
 Method of producing nanodispersed hard-alloy compositions based on double tungsten carbide and cobalt / 2372420Invention relates to electrochemical synthesis of refractory tungsten compounds and can be used for producing nanodispersed hard-alloy compositions based on tungsten carbide and cobalt, with high melting points, hardness, strength, elasticity, chemical inertness. A melt, containing, mol %: lithium tungstate 30.0 to 40.0, cobalt tungstate 2.5 to 5.0, lithium carbonate 15.0 to 20.0, sodium tungstate - the rest, undergoes electrolysis in open cells in galvanostatic mode with cathode current density ranging from 2.5 to 7.5 A/cm2. |
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Production of titanium / 2370575 Method consists in electrochemical reduction of powders and/or granules of titanium oxide and production of powders and/or granules of metallic titanium or titanium alloy in electrolyser with anode, cathode and melt electrolyte. Also electrolyte contains cations of metal chemically reducing titanium oxide and chloride-anions. Treatment of powders and/or granules and forming of semi-finished articles or finished items with concentration of chlorine at least 100 million shares are carried out upon electrolysis. |
 Catalysts of oxidation for diesel engines based on base metals and modified with base metals / 2506996Inventions 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 / 2506569 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. |
 Method of obtaining mesoporous nanosized cerium dioxide powder (versions) / 2506228Invention 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. |
 Method of obtaining calcium-doped lanthanum manganite / 2505485Calcium-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. |
 Method of processing phosphogypsum / 2504593Method 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. |
 Method of obtaining complex yttrium, barium and copper oxide / 2503621Invention 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. |
 Method of obtaining stabilised water sol of nanocrystalline cerium dioxide, doped with gadolinium / 2503620Invention 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. |
 Complex processing of coal combustion flue ash / 2502568Invention 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 / 2500502 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 / 2497755 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. |
 Method of producing titanium boride powder for aluminium electrolytic cell wetted cathode material / 2498880Invention relates to powder metallurgy. Titanium boride powder is produced by carbothermic reaction between fine powder components of the blend of anhydrous titanium boride, boric anhydride or boric acid and carbon in the form of soot. Boric acid or boric anhydride are added to powder mix in the form of solution while synthesis is conducted at the temperature not over 1473 K for 3-4 hours. |
FIELD: chemistry.
SUBSTANCE: 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.
EFFECT: invention enables to obtain pure ultrafine gadolinium hexaboride powder, increases the rate of synthesis of the end product from a molten electrolyte and reduces power consumption.
2 cl, 4 ex
The invention relates to an electrolytic process for the production of pure ultrafine powder hexaboride gadolinium.
The closest is the way to get hexaboride gadolinium using electrolysis of molten environments [Kuskov HB, Uzdenov A.S., mukogawa R.A., Vindija M.K., Saleh MMA Electrolytic method of obtaining ultrafine powder hexaboride gadolinium. Application No. 2011120024/07(029576) the Decision to grant a patent dated 21.02.2012]. The electrolysis is carried out in a glassy carbon crucible, simultaneously serves as the anode or alundum crucible; the cathode is made of tungsten. The composition of the bath to electrolysis includes gadolinium chloride and perborate potassium, background electrolyte was equimolar mixture of the chlorides of sodium and potassium. The temperature of the electrolysis of mixtures is 690-710°C, the voltage on the tub from -2,6-2.8 V, the current density of 0.1-1.0 a/cm2. The composition of the bath to obtain hexaboride gadolinium: GdCl3+KBF4+NaCl+KCl.
The disadvantages of this method are the high temperature synthesis.
The objective of the invention is to obtain pure ultrafine powder hexaboride gadolinium, increasing the rate of synthesis of the target product from the molten electrolyte and the reduction of energy consumption.
The invention consists in that joint electromedicine gadolinium and the ora of the chloride melt at the cathode and subsequent interaction at the atomic level with the formation of ultrafine powders of hexaboride gadolinium. The process is carried out in three-electrode quartz cell where the cathode is used tungsten rod; the reference electrode is a glassy carbon plate; an anode and a container - a glassy carbon crucible (also used alongby the crucible as a container for the melt and Saloglu-home plate as the anode).
Synthesis of ultrafine powder hexaboride gadolinium performed by potentiostatic electrolysis of equimolar melt KCl-NaCl-CsCl containing trichloride gadolinium and perborate potassium. In antistatically electrolysis equimolar melt KCl-NaCl-CsCl-GdCl3-KBF4hold on a tungsten electrode in the range from -2,4 up -2,6 In a relatively quasi-stationary glassy carbon reference electrode. Synthesis is carried out in an atmosphere of purified and dried argon. Cathode and electrolyte pear washed from gadolinium fluoride in the fluoride of potassium.
As a source of gadolinium use waterless trichloride gadolinium, as the source of boron - perborate potassium, as the background electrolyte is a eutectic mixture of the chlorides of potassium, sodium and cesium in the following ratio, wt.%:
the gadolinium chloride 3,0÷7,0;
perborate potassium 6,0÷10,0;
the rest is a eutectic mixture of the chlorides of potassium, sodium and cesium.
Electrolysis lead to potential the optical mode at a temperature of 550±10°C, optimal for a given solvent. Possible the implementation of synthesis and at a higher temperature, but the temperature increase leads to the evaporation of the melt, increasing the vapor pressure over the melt, loss of perborate potassium due to its thermal instability.
The choice of the components of the electrolytic bath was made on the basis of thermodynamic analysis and kinetic measurements of joint electromedicine gadolinium and boron from chloride melts. Of the compounds of gadolinium and boron containing no oxygen, gadolinium chloride and perborate potassium are fairly low melting and soluble in equimolar melt KCl-NaCl-CsCl. This background electrolyte selected from the following considerations: voltage decomposition of the molten mixture of KCl-NaCl-CsCl more voltage decay to melt GdCl3and KBF4and , besides, chlorides of alkali metals are soluble in water.
Phase composition identified by the method of x-ray phase analysis on the diffractometer DRON-6, the results confirmed the presence of only phase GdB6.
Example 1. In a glassy carbon crucible volume 40 cm3put a mixture of salt mass 37,61 g containing 2,53 g GdCl3 (6.7 wt.%); 3,63 g KBF4(9,66 wt.%); 20,67 g CsCl (54,97 wt.%), of 5.48 g of KCl (of 14.57 wt.%); 5,3 g NaCl (to 14.1 wt.%). The crucible with the salt mixture is placed in a quartz cell, and in an atmosphere of dry argon you eribaum to a temperature of the melting system (550°C). Upon reaching the operating temperature in the melt is lowered tungsten cathode. The electrolysis is carried out at a potential -2,4÷2.5 V relative of a glassy carbon electrode, the current density -0,85 A/cm2), the duration of the electrolysis 110÷120 minutes Cathode and electrolyte pear washed from gadolinium fluoride in the fluoride of potassium. The particle size of the obtained powder hexaboride gadolinium 50-70 nm.
Example 2. In a glassy carbon crucible volume 40 cm3put a mixture of salt mass 35,8 g, containing 2.2 g GdCl3(of 6.1 wt.%); 2.15 g KBF4(6,05 wt.%); 20,67 g CsCl (57,75 wt.%), of 5.48 g of KCl (15.3 wt.%); 5,3 g NaCl (of 14.8 wt.%). The crucible with the salt mixture is placed in a quartz cell, and in an atmosphere of dry argon to withstand temperature melting system (550°C). Upon reaching the operating temperature in the melt is lowered tungsten cathode. The electrolysis is carried out at a potential of-2.5÷-2,6 In a relatively glassy carbon reference electrode (current density -0,12 A/cm2), the duration of the electrolysis 110÷120 minutes Cathode and electrolyte pear washed from gadolinium fluoride in the fluoride of potassium. The particle size of the obtained powder hexaboride gadolinium 90-110 nm.
Example 3. In a glassy carbon crucible volume 40 cm3put a mixture of salt mass 33,87 g containing 1.9 grams GdCl3(5.6 wt.%); 2,73 g KBF4(8,05 wt.%); 19,94 g CsCl (of 58.9 wt.%), 4,74 g KCl (14,0 wt.%); 4,56 g NaCl (13,45 wt.%). The crucible with the Eva mixture is placed in a quartz cell, and in an atmosphere of dry argon to withstand temperature melting system (550°C). Upon reaching the operating temperature in the melt is lowered wolf-ramowy the cathode. From source serves current and-0.6 a (current density of-0.5 A/cm). The capacity is 3.5 V, the duration of the electrolysis 80÷90 minutes Cathode and electrolyte pear washed from gadolinium fluoride in the fluoride of potassium. The particle size of the obtained powder hexaboride gadolinium 70-90 nm.
Example 4. In alongby the crucible of 60 cm3put a mixture of salt mass 58,43 g containing 2.0 g GdCl3(3.4 wt.%); 3,83 g KBF4(6.6 wt.%); of 36.3 g of CsCl (62,1 wt.%), of 8.3 g of KCl (14.2 wt.%); 8.0 g NaCl (13.7 wt.%). The crucible with the salt mixture is placed in a quartz cell, and in an atmosphere of dry argon, can withstand temperatures of fusion systems (550°C). Upon reaching the operating temperature in the melt is lowered tungsten cathode. The electrolysis is carried out at a potential -2,4÷-2,5 relatively of a glassy carbon electrode, the current density and-0.4 A/cm2), the duration of the electrolysis 110-5-120 minutes Cathode and electrolyte pear washed from gadolinium fluoride in the fluoride of potassium. The particle size of the obtained powder hexaboride gadolinium 80-110 nm.
The technical result is: obtaining pure ultrafine powder hexaboride gadolinium, increasing the rate of synthesis of the target product from the molten electrolyte and the reduction of energy consumption.
1. The way the electrolytic production of ultra-fine powder Huck is aborina gadolinium, including the synthesis of hexaboride gadolinium from molten environment, including gadolinium chloride and perborate potassium in the background electrolyte, characterized in that the synthesis is carried out from the molten medium at a temperature of 550±10°C in an atmosphere of purified and dried argon, and as the background electrolyte used, the eutectic mixture of the chlorides of potassium, sodium and cesium in the following ratio, wt.%:
| the gadolinium chloride | 3,0÷7,0 |
| perborate potassium | 6,0÷10,0 |
| eutectic mixture |
| chlorides of potassium, |
| sodium and cesium | rest |
2. The method according to claim 1, characterized in that the synthesis is carried out at current densities from -0,1 up of-1.0 A/cm2and the potential electrolysis from -2,4 up -2,6 In a relatively quasi-stationary glassy carbon reference electrode.