Method and device for bringing into contact without formation of mixture and at high temperature of two immiscible fluids with heating and mixing by induction
FIELD: technological processes.
SUBSTANCE: invention relates to a method and a device for bringing two immiscible fluids into contact. Method of binging into contact without mixing of the first substance consisting of metal or alloy of metals in liquid state and the second substance consisting of salt or salt mixture in liquid state, in which: the first substance in solid state is placed in the first container, the first container is put into contact with the second substance in solid state placed in the second container, the first and the second containers are exposed to electromagnetic field effect, the first substance in liquid state is brought into motion, the second substance in solid state starts melting under the effect of heat flow from the first container, the second substance in liquid state is brought into motion, the first substance in liquid state stays in contact with the second substance in liquid state for a certain period of time, the first container is removed from the second substance in liquid state, the first container is cooled until the first substance returns into solid state.
EFFECT: improved mass transfer kinetics.
35 cl, 10 dwg, 2 tbl
SUBSTANCE: proposed method comprises immersion of alloy into salt melt to change rare-earth element from liquid alloy into melt by oxidation. Note here that said oxidation us performed in zinc chloride melt at 420-550°C while melt zinc ions are used as oxidiser.
EFFECT: higher yield.
2 tbl, 2 ex
FIELD: fuel systems.
SUBSTANCE: invention is related to recycling of return nuclear fuel (RNF) and materials of blanket region (BR) of fast breeder reactors (FBR) for their multiple use with the possibility to adjust content in creation of a new fuel composition. Initial chemical state of processed material may vary: oxides, nitrides, metals and alloys. Method represents a combination of serial processes of chemical transformation of radiated nuclear fuel (RNF): fluoridation with gaseous fluorine and extraction of main uranium mass; transition of fluoridation remains into oxides (pyrohydrolysis); - chlorination of oxides in recovery conditions with group separation of plutonium chlorides, uranium (left in process of fluoridation) and fission products. Further "plutonium" and "uranium" fraction, and also fraction containing fission products (and, possibly, minor-actinides), are used each separately in various processes according to available methods. Earlier produced uranium hexafluoride, with low boiling fluorides of fission products, is cleaned from the latter and used, according to objectives of processing, also by available methods. Using waterless processes with application of salt melts, suggested version makes it possible to realise continuous highly efficient processes of fuel components production, moreover, it is stipulated to carry out preparation stages in continuous mode. Plant for processing of spent nuclear fuel containing uranium and plutonium includes three serially installed devices: fluoridiser; pyrohydrolysis device; chlorinator-condensator-granulator device. Two last devices are of flame type. The last of devices represents a pipe with a central element, in which lines of inlet product and reagents supply are installed. In lower part there is an expansion in the form of pear with a flame burner along its axis, and medium part has a row of conical shelves inside, between which there are nozzles with pipelines for chlorides outlet. Nozzle for chlorides outlet is also arranged in lower point of pear-like part. Nozzle for exhaust of non-condensed gases is provided in upper part. Granulator is arranged as reservoir with low boiling incombustible liquid, and to produce drops, capillaries are provided at pipeline ends.
EFFECT: highly efficient method for processing of spent nuclear fuel of practically any composition from thermal reactors and fast breeder reactors, blanket region of fast breeder reactors and some other types of reactors with the possibility to produce several other types of fuel compositions.
19 cl, 3 dwg
SUBSTANCE: group of inventions concerns application of polymer-containing solution or water suspension paste and a device of ruthenium collection in gaseous discharge. The solution or water suspension paste contains one alkylene glycol polymer and/or one alkylene glycol co-polymer. The alkylene(s) contains 2-6 carbon atoms for ruthenium collection in gaseous discharge. The device includes a ruthenium collection cartridge with a substrate bearing alkylene glycol polymer or co-polymer. The alkylene(s) contains 2-6 carbon atoms.
EFFECT: improved ruthenium collection and chemical recovery of ruthenium oxide.
22 cl, 8 dwg
FIELD: nuclear engineering.
SUBSTANCE: proposed method for volume crystallization of plutonium dioxide includes treatment of molten alkali-metal chlorides with plutonium compound dissolved therein, as well as treatment of melt obtained in the process by oxygen-containing gas mixture and precipitation of large-crystal plutonium dioxide on bath bottom. In the process closed-porosity graphite granules are disposed on melt surface, their contact with melt being afforded as they are consumed. Apparatus for volume crystallization of plutonium dioxide from molten alkali-metal chlorides with plutonium compound dissolved therein has bath, cover, melt mixing system, and device for feeding soluble plutonium compounds and gas mixture to melt. Bath, parts and assemblies contacting the melt are made of ceramic material shielded at melt boundary level with pyrographite parts. Gas mixture feeding devices have ceramic and pyrographite tubes.
EFFECT: enhanced durability of equipment.
3 cl, 4 dwg
SUBSTANCE: invention relates to a method of extraction uranium refining and can be applied in the technology of processing uranium regenerated from irradiated nuclear fuel (regenerated uranium) and natural uranium chemical concentrates (NUCC). The method of extraction uranium refining includes the dissolution of uranium concentrates in nitric acid, extraction of uranyl nitrate TBP in a hydrocarbon diluent, washing the extract with uranium re-extract and re-extraction. The dissolution of uranium concentrates is combined with the extraction of uranyl nitrate, with the simultaneous supply to an extragent of an uranium concentrate and a water solution of nitric acid by counterflow.
EFFECT: simplification of a technological scheme due to the provision of obtaining the uranium re-extract, satisfying ASTM requirements, and raffinates waste by uranium.
SUBSTANCE: invention relates to metallurgy and can be used during recycling and disposal of the spent nuclear fuel. Method includes americium extraction from nitric water phase by means of its circulation in the first extractor, washing of the obtained organic phase in the second extractor, and selective reextraction of the americium in the third extractor. Then the lanthanides reextraction is performed from the obtained phase by means of its circulation in the forth extractor.
EFFECT: selective extraction of the americium is ensured from the nitric water phase containing americium, curium and fission products including lanthanides and yttrium, and optionally containing uranium, plutonium and neptunium in trace quantities.
23 cl, 2 dwg, 10 tbl, 3 ex
SUBSTANCE: milled to the coarseness of minus 0.3 mm ore is processed with a 1-40% solution of ammonium bifluoride with a ratio S:L=1:(1-5) and a temperature of 50-80°C for 1-4 hours. The obtained pulp is filtered, after which the filtrate is passed through waterless ammonia at a temperature of 25-60°C to pH 10. Then, the ammonium bifluoride solution is separated from the formed pulp, its concentration is increased to 1-40%, and supplied to re-processing of an initial raw material. The separated sediment is supplied to uranium extraction. Cakes, obtained as a result of the ore activation by solutions of ammonium bifluoride, are processed for 2-12 hours with a leaching solution with a ratio S:L=1:1, temperature of 60-80°C and residual acidity not lower than 20 g/l. The leaching solution represents a solution of sulphuric acid with the concentration 150-300 g/l, in which nitric acid is introduced as an oxidant, as well as NaCl as a complex forming reagent for gold.
EFFECT: reduction of the prime cost of the product due to the simplification of the technological process with the preservation of a degree of the uranium extraction, increased degree of the extraction of noble metals, reduction of fire hazard of the production and simplification of technological equipment construction.
12 cl, 1 dwg, 7 tbl, 6 ex
FIELD: physics, atomic power.
SUBSTANCE: invention relates to a method with which uranium from a natural uranium concentrate may be purified. The method includes extracting uranium present as uranyl nitrate in an aqueous phase A1 resulting from the dissolution of the natural uranium concentrate in nitric acid using an organic phase which contains an extractant in an organic diluent; washing the organic phase obtained at the end of step a), with an aqueous phase A2, and extracting the uranyl nitrate from the organic phase obtained at the end of step b), by circulating said organic phase in an apparatus as a counter-current of an aqueous phase A3. The extractant is an N,N-dialkylamide and the ratio between the flow rate at which the organic phase obtained at the end of step b) and the aqueous phase A3 circulate in the apparatus where step c) occurs, is greater than 1.
EFFECT: high efficiency of purifying uranium by preventing loss of uranium in the organic phase.
15 cl, 2 tbl, 4 ex
FIELD: physics, atomic power.
SUBSTANCE: invention relates to methods of processing uranium-containing solutions obtained from dissolving fluorination cinder when producing uranium hexafluoride. The method includes dissolving cinder in nitric acid solution, extracting uranium from the fluorine-containing nitric acid solution via reduction thereof with hydrazine on a platinum catalyst, with constant removal of uranium tetrafluoride precipitate from the catalyst surface, separating the catalyst from the nitric acid solution and the uranium tetrafluoride precipitate, providing an equimolar radio of fluoride ions to uranium (IV) in the obtained solution and separating the uranium tetrafluoride precipitate from the nitric acid solution, wherein the nitric acid solution is reused to resolve fluorination cinder with preliminary fortification with nitric acid.
EFFECT: invention provides a high degree of reducing uranium and reduces the amount of nitrate- and fluorine-containing wastes.
3 cl, 2 dwg
SUBSTANCE: invention relates to hydraulic metallurgy, particularly to extraction of uranium from used phosphate solutions. This process consists in adding the solvent to initial solution, said solvent being selected from the series: KMnO4, K2Cr2O7, HNO3, H2O2, KClO3. Then, uranium-bearing sediment is precipitated by acidity correction by ammonia to pH 2.8-4.0 at 20-35°C. Filtered precipitate is treated by 20-35% solution of NaOH at 80-85°C for 1.5-2.0 hours.
EFFECT: higher yield of uranium, return of high-enriched uranium to fuel cycle, lower costs of higher safety at long-term storage, accounting and control.
2 cl, 1 tbl, 4 ex
SUBSTANCE: method involves leaching a concentrate with aqueous nitric acid solution at high temperature to obtain a pulp which consists of a solid phase and an aqueous phase, filtering off the aqueous phase in form of uranyl nitrate solution, extraction refining uranium using tributyl phosphate in a hydrocarbon diluent. The filtered uranyl nitrate solution, which contains uranium in concentration of 200-400 g/l, dissolved silicon in concentration of 1.0-3.2 g/l and nitric acid in concentration of 1-2 mol/l, is held until stabilisation of viscosity before being fed for extraction.
EFFECT: preventing escape of the aqueous phase with the uranium extract, which improves efficiency of the extraction stage, lowers content of impurities in the uranium extract and enables to obtain a product which meets ASTM C 788-03 requirements.
1 dwg, 1 tbl
SUBSTANCE: invention relates to method of uranium extraction from mother liquors. Method includes obtaining resin, modified by aminophosphonic groups, and obtaining mother liquor, which contains from 25 to 278 g/l of sulphate and uranium. After that, mother liquor is passed through resin, modified by aminophosphonic groups, in acid form to separate uranium from mother liquor. Then, elution of uranium from resin is realised.
EFFECT: possibility of sorption extraction of uranium from solutions, which contain high concentrations of sulfate.
7 cl, 1 tbl, 3 ex
SUBSTANCE: proposed process comprises leaching of uranium by nitric acid and separation of water phase from undissolved precipitate. Then, undissolved precipitate is mixed with fluorine-bearing agent, dissolution of produced charge and/or charge as a suspension in nitric acid solution. Produced solution is returned to production process for extraction of uranium. Nitric acid concentration in solution makes at least 2 mol/l. Dilution is carried out at fluorine-ion concentration at, at least, 15 g/l. Dilution is performed at 60-100°C.
EFFECT: decreased losses of uranium, minimised wastes.
4 cl, 1 dwg, 1 tbl
SUBSTANCE: method involves dissolving wastes in concentrated nitric acid, oxalate precipitation from the solution, drying and calcining the americium oxalate to americium dioxide. The solution obtained by dissolving wastes with high concentration of impurity cations, one of which is ferric iron, is mixed with a reducing agent for reducing ferric iron to ferrous iron. After reduction, the solution with acidity by nitric acid of 1-2.5 mol/l is taken for extraction of americium with a solid extractant based on different-radical phosphine oxide, followed by washing and re-extraction of americium. Oxalate precipitation is carried out from the re-extract with americium concentration of not less than 3 g/l and nitric acid concentration of not less than 3 mol/l, said precipitation being carried out in two steps: adding an oxalate ion to the americium-containing solution in weight ratio to americium of (2-7):1 and then adding water to the separated precipitate in volume ratio to the precipitate of (3-8):1 and the oxalate ion in weight ratio to americium of (1-4):1. The obtained reaction mixture is boiled and taken for separation of americium oxalate from the solution.
EFFECT: high output of the product and degree of purity thereof.
SUBSTANCE: invention relates to metallurgy, namely to the production of ferroalloys - ferrochrome and ferrotitanium. The method involves mixing of powders of initial components of a charge containing an ore concentrate and aluminium as a reducing agent, initiation of the combustion process, mechanical separation of the obtained cast ferroalloy from slags. An oxidiser in an amount of not more than 15 wt % is additionally added to the charge; an alkali metal perchlorate is used as the oxidiser, and to the composition of the reducing agent there added is not more than 15 wt % of magnesium or alloy of aluminium with magnesium in the amount sufficient for the complete reduction of oxides from ore concentrates; with that, the total content of the reducing agent in the charge is not more than 30 wt %; the charge is arranged in a capacity made from graphite or boron nitride; initiation of the combustion process in the air is performed by means of a tungsten spiral.
EFFECT: invention allows reducing power consumption at high efficiency of the process; prime cost and time required for the process at the maintenance of a high degree of extraction and purity of the target product.
3 cl, 1 tbl