Method of converting waste uranium hexafluoride into uranium metal |
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IPC classes for russian patent Method of converting waste uranium hexafluoride into uranium metal (RU 2444475):
 Method for extracting rare metals from ash-slag masses of used underground gas generator / 2443788
Intensified extraction of underground water is performed from used underground gas generator through the main water drain wells. Then, there created is cone of depression in the section of used underground gas generator for minimisation of underground water level and maintenance of maximum depression in the section of used underground gas generator. Treatment of ash-slag masses is performed using the solvent injected to the used underground gas generator, and leaching and collection of rare metal dissolved in the solvent extracted from underground gas generator is performed in surface chemical complex.
 Procedure for processing uranium ore / 2434961
Silicate uranium ore is crushed and crumbled; further, it is leached with sulphuric acid with addition of nitric acid as oxidant. Uranium is extracted and refined from impurities using mixture of extragents. Also as mixture of extragents there is used synergetic mixture containing di(2-ethyl-hexyl)phosphoric acid - 0.05-0.075 mole/l, tri-alkyl-amine - 0.05-0.075 mole/l in hydrocarbon dissolver at ratio of volumes of organic and water phases VO-VW= 1-3÷6. Upon extraction organic phase saturated with uranium is washed with solution of sulphuric acid. Further, uranium is re-extracted with solution of coal-ammonia salts producing crystals of ammonia-uranyl-tri-carbonate and is filtered. Produced crystals are tempered to production of protoxide-oxide of uranium.
 Processing method of nitric-acid solution of regenerated uranium with removal of technetium (versions) / 2430175
Processing method of nitric-acid solution of regenerated uranium involves uranium (VI) extraction with tributyl phosphate in organic diluter; flushing of extract with nitric-acid solution and re-extraction of uranium. At that, removal of technetium from uranium is performed by shifting technetium (VII) to non-extracted quadrivalent state in flushing zone of extraction cascade with the use of flushing solution containing 0.1-0.2 mol/l of carbohydrazide and 0.05-0.15 mol/l of nitric acid. Extract is flushed at the ratio of flows of organic and water phases, which is equal to 10-15. Method can be implemented in two versions. As per the first version, used flushing solution is supplied to feed stage of extraction cascade and technetium is removed to raffinate. As per the second version, used flushing solution is a separate flow from which uranium is extracted by contact with flow of fresh extractant; organic phase is connected to initial uranium extract prior to supply to flushing zone, and technetium is removed to separate product the volume of which is 5 times less than the raffinate volume.
 Procedure for separation of actinoide from lanthanide in water medium by complexation and membrane filtration / 2427658
Procedure consists in stage of introduction of complex forming compound to contact with water medium containing said actinoid and one or more lanthanides. Also, the said complex forming compound in not complexated state is not retained with the said membrane and is capable to form complex with said actinoid containing the said element and at least two molecules of the said complex forming compound, also, complex is capable to be retained with the membrane. Further, there is performed the stage of water medium passing through the membrane for formation of filtrate containing water effluent depleted with said actinoid from one side, and retentate containing the said complex.
![Para-tert-butyl-calix[6]arenes, containing three acid functional groups in positions 2, 4 and 3, liquid membranes deposited on substrate, substrate materials containing said membranes and use thereof](http://img.russianpatents.com/img_data/1082/10826472-s.gif) Para-tert-butyl-calix[6]arenes, containing three acid functional groups in positions 2, 4 and 3, liquid membranes deposited on substrate, substrate materials containing said membranes and use thereof / 2422432
Present invention relates to substrate material for complex formation and selective extraction of americium, plutonium, uranium or thorium in their cationic form, which is para-tert-butyl-calix[6]arene of formula
Procedure for extraction of uranium / 2412266
Procedure consists in production of sample containing uranium and silicon dioxide, in treatment of sample containing uranium and silicon dioxide and in production of material containing dissolved uranium and silicon dioxide. Also, material contains SiO2 over or equal to 100 mg/l. Further, dissolved uranium is extracted from material using at least one strong base anion-exchanging resin of macro-reticular structure. There is obtained uranium containing product in combination with strong-base anion-exchanging resin of macro-reticular structure. Further, uranium containing product is eluted and extracted from combination with strong-base anion-exchanging resin of macro-reticular structure.
Procedure for processing refractory ore and concentrates / 2412262
Procedure consists in processing refractory ore and concentrates with chlorine at presence of water and complex former in kind of sodium chloride, in converting gold into solution, in separating solution from precipitated sediment, and in washing sediment with water producing flush water. There are processed refractory ore and concentrates with low contents of gold and uranium, where uranium is additionally extracted. Also, for processing there is used chlorine in atomic or molecular state. Chloride or sodium sulphate are used as complex formers. Processing is carried out at weight ratio L:S (liquid: solid) (1-1.5) during 1-2 hours at temperature 20-70°C with simultaneous gold and uranium passing into solution.
 Procedure for extraction of uranium and molybdenum from carbonate salt uranium-molybdenum water solutions / 2409688
Procedure consists in extracting uranium by means of liquid extraction of organic phase of synergy mixture on base of di(2-ethylhexyl)phosphorous acid containing tributylphosphate (TBP) or tributylphosphate together with trialkylamine (TAA) or heteroradical phosphynoxide of composition of oxide of isoamyldioktylphosphyne in organic thinner. Also, while mixing, there is performed simultaneous gradual neutralisation of mixture of phases with mineral acid till there are established balanced values of pH of water phase in interval 5.6-6.6.
 Procedure for processing persistent uranium containing pyrite and valuable metals of materials for extraction of uranium and production of concentrate of valuable metals / 2398903
Procedure consists in sulphuric acid leaching of uranium. Also source material of 0.1-0.3 mm dimension is subjected to sulphuric acid leaching in autoclave till over 95% of uranium is transited to solution and till degree of pyrite oxidation reaches not less, than 50%. Upon separation of uranium containing solution from a solid phase in form of a cake the latter is conditioned by flotation of valuable metals with sulphydric collector and oxy-ethylated compound at pH 2.5-7.0 thus producing concentrate of valuable metals.
Procedure for processing chemical concentrate of natural uranium / 2398036
Invention refers to procedures for processing chemical concentrate of natural uranium. The procedure consists in dissolving natural uranium in solution of nitric acid, in directing solution to uranium extraction with tri-butyl-phosphate and hydrocarbon thinner, in washing extract with re-extract and in uranium re-extracting. There is dissolved chemical concentrate of natural uranium with increased content of phosphorus and sulphur. Uranium is extracted from solutions with increased concentration of phosphorus and sulphur and with concentration of nitric acid 30÷80 g/l to 60÷75% saturation of extractant with uranium. Also this level of extractant saturation with uranium in the said range in % is maintained not exceeding value equal to (0.3×[HNO3]+51), where [HNO3] is concentration of nitric acid in solution directed to extraction, in g/l.
Method of extracting uranium from sodium fluoride sorbent / 2422366
Invention can be used in processing wastes containing uranium fluorides. Sodium fluoride sorbent which contains uranium (V) is treated with water vapour at temperature 100-250°C. Uranium is then extracted through fluorination at temperature not higher than 400°C.
Uranyl fluoride-based sorbent and method of its production / 2422199
Invention relates to production of sorbents used for treatment of uranium hexafluoride made from irradiated nuclear fuel to remove plutonium heaxafluoride. Proposed sorbent comprises uranyl fluoride and additive to increase sorbent porositity selected from fluorides of calcium, magnesium, strontium and barium in amount of 5-25 wt %. Said sorbent is produced on mixing uranyl fluoride and aforesaid additive. Obtained mass is formed and dried at 20-25°C on heating in 75°C, 120°C and 150°C steps.
Uranium hexafluoride obtaining method / 2400430
Invention can be used in nuclear power industry. Uranium hexafluoride is obtained by fluor treatment of uranium-containing compounds in flame reactor. Process gas leaving the reactor is cooled in heat exchanger by alternate-intermittent feed of cooling agents to sections of tubular heat exchanger so that some sections operate in mode of uranium hexafluoride desublimation on its walls with further distillation, and the rest sections - in the mode excluding uranium hexafluoride desublimation. Cooling agent is supplied with temperature of 5-20 °C during 5-15 minutes to pipe heater sections operating in desublimation mode; after that supply of cooling agent is stopped. When temperature of cooling agent in sections is 60-65 °C, supply of cooling agent with temperature of 65-75 °C is open by switching over those sections to the mode excluding uranium hexafluoride desublimation.
 Method of producing uranium tetrafluoride / 2397145
Invention can be used to produce nuclear fuel. Uranium metal is dissolved in a solvent containing hydrochloric acid with concentration of 50-200 g/dm3, and fluoride compounds of uranium (IV) with uranium concentration of 30-300 g/dm3 and molar ratio of uranium to fluorine equal to 1:(1.6-4.0). During the entire process of dissolving uranium metal, the said concentration of hydrochloric acid is kept on a constant level through its further addition. A hydrate of uranium tetrafluoride is precipitated from the obtained hydrofluoric acid solution. The pulp is washed with water, filtered, dried and the uranium tetrafluoride residue is roasted. The fluoride compounds of uranium can be obtained by heating uranium dioxide, uranium tetrafluoride or fluoride and chloride salts of uranium separately or together in the presence of hydrofluoric and hydrochloric acid.
Method of obtaining uranium tetrafluoride / 2396212
Invention relates to atomic industry and can be applied in technological processes of obtaining uranium tetrafluoride and in production of metallic uranium. Method of obtaining uranium tetrafluoride includes dissolution of uranium dioxide, sedimentation of uranium tetrafluoride from obtained solution by supplying hydrofluoric acid. After that carried out are pulp filtration, sediment washing, drying and burning. Dissolution of uranium dioxide is carried out in mixed solution of hydrochloric and hydrofluoric acids obtaining solution of complex uranium compound with uranium concentration up to 480 g/l. Uranium tetrafluoride from solution is precipitated in form of crystal hydrate by dosed supply of hydrofluoric acid during 15-30 min, without forced heating of reaction medium.
 Method of producing hexafluorides of actinide elements and device for realising said method / 2394770
Invention can be used in nuclear power engineering to process irradiated nuclear fuel and in isotope separation technology. Hexafluorides of actinide elements are obtained by treating compounds of actinide elements with a single stream of molten fluoride salts in two circulation loops with division of the gas phase of each of the loops. Non-sol forming compounds of actinide elements are treated in the first circulation loop with molten fluoride salts. The molten mass of oxides obtained in fluoride salts is fed into the second circulation loop and treated with fluorinating agents to obtain gaseous hexafluorides of actinide elements. The device for producing hexafluorides of actinide elements has a housing 1, in which there is a unit for dissolving actinide elements and a fluorinating unit in form of communicating vessels separated by a partition wall 2, with gas-separating chambers 13, 14 in the upper parts of each of the vessels. Each of the vessels is divided by a partition wall 4, 5 and is fitted with tuyeres 10, 11 for supplying reaction gases in the lower parts of the communicating vessels.
 Method of receiving of uranium dioxide powder receiving by method of pyro-hydrolysis and installation for its implementation / 2381993
Into preheated reaction chamber there is fed uranium hexafluoride, hydrogen and water vapour, wich react with each other with formation of uranyl fluoride powder. From below of chamber it is fed mixture of water vapour, hydrogen and nitrogen with creation over gas-distributing grid of area of fluidisated layer for reconditioning in it of received uranyl fluoride up to uranium dioxide. Into electric furnace it is introduced mixture of water vapour, hydrogen and nitrogen for providing of post reduction of unreacted powder. It is cooled and stabilised received powder. It is fed powder into milling and through magnetic separator it is charged into bin - moisture tester, in which it is measured moisture of powder by amount of skips of neutrons from irradiator to receiver with following rejection of finished powder with moisture more than 1 %.
 Method of treating contaminated uranium material / 2377674
Invention relates to a nuclear fuel cycle, and specifically to methods of treating contaminated hazardous 232U, 234U, 236U isotopes of uranium material on a gas centrifuge cascade. The method involves treating contaminated uranium material fed into a gas centrifuge cascade, obtaining low enriched uranium from cascade selection using natural uranium hexafluoride in an intermediate cascade selection into which natural uranium hexafluoride is fed, producing a product with low concentration of at least one of the hazardous 232U, 234U, 236U isotopes compared to contaminated material with mass ratio of contaminated uranium material to natural uranium hexafluoride taken for treatment equal to (1÷25):100.
 Method of fluorinating oxides of actinide elements to hexafluorides and device to this end / 2356841
Present invention relates to inorganic chemistry, particularly to methods of fluorinating oxides of actinide elements and can be used in the atomic industry in nuclear reprocessing, as well as in the technology of separating isotopes. The method of fluorinating oxides of actinide elements to hexafluorides involves melting oxides of actinide elements in fluorine layers, passing gaseous fluorinating agent through the melt and oxidation with subsequent removal of gaseous hexafluorides from the reaction zone with constant circulation of the melt from the processing zone to the melting zone. The fluorinating process is carried out in a foam-liquid layer. The fluorinating agent used is tetrafluoromethane mixed with oxygen. Removal of actinide elements in form of hexafluorides into the gas phase from molten fluorine salts in the zone of their treatment with reaction gases can be partial or complete. The device for fluorinating oxides of actinide elements to hexafluorides has a unit for input of fluorine salts and oxides of actinide elements, a reactor for melting the oxides in a melt of fluorine salts and a reactor for treating the obtained melt with gases, a device for inlet of gases, and a liquid phase baffle plate.
Method of uranium hexafluoride production / 2355641
Invention can be used in nuclear technology. Uranium oxides with valency from +4 to +6 undergo the reaction with hydrogen fluoride forming the intermediate containing 40÷80 wt % of uranylfluoride or uranium tetrafluoride, the rest is initial products. Then obtained intermediate product is directed to flame reactor for fluorination by elemental fluorine taken in the excess 5÷7 %. The obtained uranium hexafluoride is separated from gas phase by desublimation. The fluorine-containing products remaining in the gas phase after desublimation are taken for entrapment by the initial uranium oxides.
Method of unloading of uranium hexafluoride from steel containers and utilization of these containers utilization / 2244683
The invention is dealt with the methods of extraction of liquid and gaseous substances from steel containers and utilization of these containers. The invention allows extract uranium hexafluoride from steel containers of any volume filled in with uranium hexafluoride irrespective of the share of uranium isotope 235. The method provides for heating of the container in a closed space up to the temperature of uranium hexafluoride transition into a gaseous state. The process is conducted in a tight induction furnace with a metal segmented chilled crucible, a penetrable for an electromagnetic field metal transported chilled tray, a metal chilled inductor and a metal chilled body. The method is realized in two stages: heating of the container up to the temperature of 70-195°С and aging in the heated state under action of inductive currents at a frequency of 500-70000 Hz. The temperature of the crucible sections, the tray, the inductor and furnace body is kept in the limits of 70-195°С. Cooling of the crucible sections, the tray, the inductor and the furnace body is conducted with a high-boiling organic heat-transfer agent: diphenyl, orthoterphenyl and others.
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FIELD: chemistry. SUBSTANCE: invention relates to ecology and is aimed at preventing environmental pollution and radiation poisoning. The method of converting waste uranium hexafluoride into uranium metal and calcium fluoride involves reaction of uranium hexafluoride and calcium metal, where gaseous uranium hexafluoride is fed into molten calcium metal by bubbling, and operating temperature is kept higher than the melting point of calcium fluoride. EFFECT: invention enables conversion of toxic radioactive uranium hexafluoride into an non-volatile compact product which is safe for storage. 1 ex
The invention relates to the field of ecology, it is aimed to prevent the possibility of pollution and poisoning of the population with radioactive substances. The separation of uranium isotopes, resulting in two fractions: enriched with isotope235U more to 0.72 wt.% and moldboard, which contains 0.1 to 0.3 wt.%235U. Talking uranium hexafluoride is stored in containers, mostly in open areas. This represents a significant risk to the environment and population. As a result of corrosion during long-term storage, the action of natural phenomena (storm, earthquake), as well as sabotage and bombing can disrupt the integrity of part of the container and the environment will be hexafluoride uranium is radioactive, poisonous gas, having a stifling effect that can lead to mass poisoning of the population. A method of refining uranium hexafluoride in tetraploid uranium, [Fsatom, Damluji, Vulgarities Nuclear fuel based on enriched uranium, Atomizdat, M., 1966, p.42-47]. According to this method through the nozzle type "pipe in pipe" on the outside of the reactor is hydrogen, and then through the interior of the nozzle begin to apply a mixture of uranium hexafluoride and fluorine, and fluorine is supplied to achieve the desired temperature. The origin is W ill result in the following response: UF6(gas)+H2(gas)→UF4(TV.)+2F(gas)ΔN329=-280 kJ/mol; F2(gas)+H2(gas)→2F(gas)That ΔN298=-268 kJ/mol. Excess hydrogen 100-500%, the flow rate of the fluorine 20-32 g/kg UF6, 90% received UF4settles at the bottom of the hopper, UF4carried by the gases is captured cermet filters. The disadvantage of this method is to obtain free-flowing powdery product of relatively low density (ρ(UF4)=6.7 g/cm3), which makes its storage. There is a method of conversion of depleted uranium hexafluoride to uranium oxide (U3O8by high-temperature pyrohydrolysis [Proven management for depleted uranium: the French reference of Cogema's defluorination plant / P.Netter, B.Dupperret, B.Le Motais. International Conferences "Decomissioning, decontamination and reutilization of commercial and government facilities". Knoxville, USA, September 12-16, 1999. - 11 R.]. The disadvantage of this method is the high energy intensity of the process and the final product in powder form, which can worsen the ecological situation in the case of damage to the packaging. A known method of converting uranium hexafluoride in tetrafide uranium and anhydrous hydrogen fluoride and device for its implementation (patent RU No. 2188795 C2 from 23.11.2000). The invention can be used for processing of depleted uranium hexafluoride. The method consists in collaboration the AI of uranium hexafluoride with hydrogen in hydrofluoric flame. The process is conducted in a reactor at a pressure in it 540-720 mm Hg Molar ratio of the components UF6:F2: H2=1:(0,12-0,36):(1,5-3). As a reducing agent can be used cathode gas. The temperature of the walls of the reactor support about 480°C. Cooling of the reaction products is carried out by cooling the walls of the reactor. Powder tetrafluoride uranium auger-feeder discharge device is moved to the receiver of the finished product. Body discharge device made in the form of a vertical oval. Hydrogen fluoride from the process gases condense at the temperature (-35)-(-40)°C and (-70)-(-80)°C. Additionally remove HF sodium fluoride at temperatures of 70-80°C and 20-30°C. the Desorption of hydrogen fluoride is carried out at a temperature of 350-375°C. The invention: the degree of conversion of uranium hexafluoride in tetraploid uranium up to 99.5%. The degree of extraction of hydrogen fluoride to 99.6%. The disadvantage of this process is that the final product is a powdery product - tetraploid uranium in the accident and pollutes the atmosphere, and hydrosphere. A method of obtaining powder of uranium dioxide of uranium hexafluoride (patent RU 2381993 from 16.01.2008), including the filing in a pre-heated reaction zone of the reaction chamber of uranium hexafluoride and steam, feeding the second of reaction the th zone of the reaction chamber a mixture of water vapor and hydrogen transfer in this area uranylnitrate to uranium dioxide the discharge of powder from the reaction chamber dovolenkovania unreacted uranylnitrate. The resulting powder was cooled and stabilized with a mixture of air and nitrogen. The disadvantage of this method is: - multi-stage operations; the end product is obtained in powder form, which complicates storage and gives the possibility of environmental pollution. A known method of recovering uranium hexafluoride adopted for the prototype (patent RU №2204529 C2 from 28.03.2001). The invention relates to methods for recovery of uranium hexafluoride to the lowest fluoride and uranium metal and can be used in the processing of depleted uranium hexafluoride. The result of the way: the possibility of obtaining a product of a given composition and the implementation of reduction reaction of uranium hexafluoride at a lower temperature. Recovery UF6carry out pre-comisioane hydrogen in the chemical reactor in a mixture with a buffer gas-diluent continuous spontaneous combustion. Atomic hydrogen is produced by mixing in the flow of molecular hydrogen in excess of the molecular fluorine ignited in the burner unit, so that the excess molecules of fluorine thermally dissociates into atoms of fluorine. Recovery UF6 is carried out to uranium metal at a ratio of conc the Nations of atomic hydrogen and UF6 molecules in the mixture, fed to the reactor, 6:1, respectively. Recovery of UF6 to carry tetrafluoride uranium at a ratio of concentrations of atomic hydrogen and molecular UF6in the mixture fed to the reactor, 2:1, respectively. The disadvantage of this method is metallic uranium is obtained in the form of fine pyrophoric powder is not suitable for storage. The objective of the invention is the transfer of toxic radioactive uranium hexafluoride in non-volatile compact product - uranium metal ingot, not having vysokopronitsaemogo gamma activity. A method of converting waste uranium hexafluoride to uranium metal includes the interaction of uranium hexafluoride and metallic calcium. Gaseous uranium hexafluoride is introduced into the molten metal calcium by sparging. The temperature of the process for obtaining a compact ingot uranium is supported above the melting point of calcium fluoride. Proposed in the present invention method has several advantages: the product of the process is a compact ingot of metallic uranium, which occupies a small volume (the density of α-uranium 19,05 g/cm3). The resulting product nesius, Neleus (the boiling point of uranium metal 3813°C). In addition to uranium ingot obtained slag consisting of calcium fluoride, which you can use to acquire the Oia of fluoride. The translation process of uranium from waste hexafluoride urn in uranium metal is proposed to carry out by bubbling gaseous uranium hexafluoride through the molten metal by the reaction of calcium
The reaction is practically irreversible, because the change in free energy of the process is more negative -1440 kJ/mol. In the process releases a significant amount of heat (ΔH Example In the apparatus, which is a cylindrical vessel with a lid flange is loaded metal calcium, then the device is sealed, it is pumped out the air, after which it is filled with argon. The apparatus is moved into a furnace and heated to melt the calcium. The heating is turned off, and through the pipe in the upper part of the melt of calcium is served gaseous uranium hexafluoride from heated sublimator. The number Bartiromo of uranium hexafluoride shall not exceed 95% of the stoichiometric amount for reaction with the loaded amount of calcium. Under these conditions, the reaction products according to their densities are distributed in the following order: bottom layer - melt uranium metal, the middle layer of the molten slag (Ca 2), the upper layer of excess calcium. After cooling and crystallization of the reaction products are extracted from the reactor and share: ingot uranium metal is deposited, the slag - receiving fluoride, metal calcium reuse. A method of converting waste uranium hexafluoride into uranium metal and calcium fluoride, including the interaction of uranium hexafluoride and metallic calcium, and gaseous uranium hexafluoride is introduced into the molten metal calcium through sparging, the process temperature is maintained above the melting point of calcium fluoride.
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