WO2012084740A1 - Procédé de conversion d'uo3 et/ou de u3o8 en uo4 hydraté - Google Patents
Procédé de conversion d'uo3 et/ou de u3o8 en uo4 hydraté Download PDFInfo
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- C01B15/00—Peroxides; Peroxyhydrates; Peroxyacids or salts thereof; Superoxides; Ozonides
- C01B15/04—Metal peroxides or peroxyhydrates thereof; Metal superoxides; Metal ozonides; Peroxyhydrates thereof
- C01B15/047—Metal peroxides or peroxyhydrates thereof; Metal superoxides; Metal ozonides; Peroxyhydrates thereof of heavy metals
- C01B15/0475—Metal peroxides or peroxyhydrates thereof; Metal superoxides; Metal ozonides; Peroxyhydrates thereof of heavy metals of actinides
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Definitions
- the invention relates to a method for converting U0 3 or U 3 O 8 into hydrated UO 4 .
- uranium ore processing is to extract the uranium from the ores, to purify it and to combine it in order to obtain a product called uranium-containing concentrate or uranate or "Yellow Cake", for example comprising more than 70% by weight of uranium.
- the uranium ores are first crushed, then crushed, and then subjected to an operation of solution of the uranium with a base or an acid, such as for example carbonate sodium or sulfuric acid, called attack or leaching.
- a base or an acid such as for example carbonate sodium or sulfuric acid
- the uranium is recovered in the form of liquors, solutions, uraniferous, uranic, generally acidic, in sulphate medium for example.
- These solutions may also be in a chloride, ammonia, nitrate or carbonate medium according to the prior purification-concentration step.
- the uranium concentrate or "yellow cake” is obtained from these liquor solutions, uranifers by precipitation using precipitation reagents such as sodium hydroxide, magnesia, ammonia, uranyl ammonium tricarbonate , and hydrogen peroxide H 2 O 2 , filtration and drying.
- the uranium concentrate or "yellow cake” will be respectively based on sodium uranate, magnesium uranate, ammonium diuranate, uranyl ammonium tricarbonate, or uranium peroxide.
- the uranium concentrate or "yellow cake" thus prepared is then transformed in particular into UF 4 and then UF 6 .
- Uranium concentrates such as the yellow cake described above, but also other uraniferous concentrates containing uranium trioxide or uranium octa-uranium oxide are not suitable for conversion. direct especially in UF6.
- the concentrates are purified before being converted.
- a purification process is known in which the yellow cake is first dissolved in nitric acid and then the solution is sent to a countercurrent liquid-liquid extraction apparatus in which the nitrate of Uranyl solution is extracted using a mixture of TBP and kerosene.
- This process is complex and uses nitrates and volatile organic compounds that must be managed.
- Some impurities added may partially follow the uranium, despite repeated washing, and are troublesome for the UF conversion process.
- the process of this document comprises a prior step of dissolving the concentrate with nitric acid with all the disadvantages of such a step listed above.
- Document FR-A-2 438 623 relates to a process for purifying hydrated peroxide of uranium VI in which a uranium concentrate is digested in an acidic aqueous solution, in particular a nitric acid solution, in the presence of a complexing agent fluorides so as to obtain an aqueous solution of uranium, and this aqueous solution of uranium is reacted with a peroxide to precipitate the hydrated peroxide of uranium VI.
- the document FR-A-2 429 747 relates to a process for the preparation of hydrated peroxide of uranium VI from hydrated tetrafluoride of uranium, in which the hydrous tetrafluoride of uranium is digested in an acidic solution, in particular a solution of nitric acid, in the presence of a fluoride precipitating agent, for precipitating the fluoride ions and obtaining an aqueous solution of uranium, filtering and adjusting the pH of the aqueous solution of uranium and reacting the solution aqueous uranium with a peroxide to precipitate the hydrated peroxide of uranium VI.
- the process of this document comprises a prior step of dissolution of the concentrate with an acid, especially nitric acid, with all the disadvantages of such a step listed above.
- This process must also make it possible to prepare hydrated uranium peroxide having a high specific surface area and high reactivity for conversion to UF.
- the object of the present invention is to provide a method for converting U0 3 or U 3 O 8 to hydrated UO 4 which meets all the needs and requirements listed above.
- the object of the present invention is also to provide such a method which does not have the disadvantages, defects, limitations and disadvantages of the processes of the prior art, as represented in particular by the documents mentioned above, and which solves the problems of the processes of the prior art.
- step d optionally, repeating step d); f) optionally, drying the precipitate, crystals;
- the pH of the suspension is adjusted during step a) to a value of between 2 and 3 by adding an acid to the suspension.
- said acid is selected from oxalic acid, sulfuric acid and mixtures thereof.
- the stoichiometric excess of H 2 O 2 is more than 1 to 10, preferably 1.5 to 3, relative to the stoichiometry of the reaction (1), and more than 1.33 to 10 per relative to the stoichiometry of the reaction (2).
- the hydrogen peroxide is added in the form of an aqueous solution at a concentration of 30% to 70% by weight.
- the aqueous suspension of UC 3 and / or U 3 O 8 has a uranium concentration of 10 to 500 g / L (gU / L), preferably 100 to 200 g / L for UO 3, and from 10 to 500 g / l, preferably from 100 to 200 g / l, for example 250 g / l for UsOs-
- steps a) and b) can be carried out with stirring.
- step a) and / or step b) complexing anions are added to the suspension.
- said complexing anions are chosen from sulphate anions, oxalate anions, and mixtures thereof.
- the duration of step b) is chosen so that the conversion of UO 3 and / or U 3 O 8 to hydrated UO 4 is total or substantially total, for example greater than 99%, or even 99, 9%.
- step b) may comprise the following successive steps b1) and b2): bl) addition of hydrogen peroxide H 2 O 2 to the aqueous suspension of a powder of U0 3 and / or U 3 0 8 , preferably with stirring, then stopping the addition;
- the duration of said step b1) may be from 1 to 8 hours, preferably from 1 to 3 hours, and the duration of step b2) may be from 1 to 24 hours, preferably from 1 to 3 hours.
- step b2 the addition of hydrogen peroxide H 2 O 2 is carried out throughout the duration of step b), i.e., step b2) is omitted.
- the duration of step b) is generally 1 to 8 hours, preferably 1 to 5 hours.
- the suspension is subjected to the action of ultrasound.
- the water of the suspension can be removed by evaporation, and the precipitate, the crystals of UO 4 hydrate, are then recovered in the form of a dry solid, for example a moisture of less than 7% in bulk, usually consisting of U0 4 , 2H 2 0, or, in step c), the precipitate, the crystals of UO 4 hydrate are separated from the suspension by a solid / liquid separation operation, for example a filtration or centrifugation operation, in the form of a moist solid, for example a moisture of 30% to 80% by weight, generally consisting of UO 4 , 43 ⁇ 40.
- a solid / liquid separation operation for example a filtration or centrifugation operation
- a moist solid for example a moisture of 30% to 80% by weight
- said wet solid is washed at least once with a washing liquid.
- said washing liquid is selected from demineralised water; acidified aqueous solutions, preferably at a pH of 2 to 3, for example with sulfuric acid; solutions containing a complexing agent impurities contained in the wet solid.
- the washing ratio defined by the ratio of the mass of the washing liquid to the mass of the wet solid is from 1 to 30, preferably from 1 to 10.
- the oxide U0 3 and / or the oxide U 3 O 8 is in the form of a uraniferous concentrate called "Yellow Cake", or the oxide U0 3 and / or the oxide U 3 O 8 come from the drying and then the calcination of a uranium concentrate based for example on hydrated UC, ammonium diuranate, or uranium tricarbonate obtained by precipitation in a reactor, in particular in a reactor with fluidized bed, from a uranium solution.
- the process according to the invention can be defined as a method of direct conversion without prior dissolution of U 3 O 8 and / or UO 3 by the addition of H 2 O 2 to an aqueous suspension of a U 2 O 3 powder. 8 and / or a powder of U0 3 .
- the method according to the invention comprises a series of specific steps which has never been described in the prior art.
- the process according to the invention is fundamentally different from the processes of the prior art, in that no prior dissolving of U 3 0 8 and / or UO 3 is carried out before carrying out their conversion by addition of hydrogen peroxide.
- the process according to the invention which does not include a step of prior dissolution of the uranium does not have all the disadvantages due to this preliminary dissolution step.
- the process according to the invention thus avoids the formation of numerous impurities which can be extremely troublesome in the subsequent conversion steps of the hydrated UC, for example in UF.
- the process according to the invention is further defined by the fact that the suspension contains a stoichiometric excess of H 2 O 2 with respect to reactions (1) and (2), which makes it possible to obtain a total or almost total conversion. .
- the process according to the invention is further characterized in that the pH of the suspension is maintained in steps a) and b) at a specific value of between 2 and 3.
- the selection of this very small pH range makes it possible, on the one hand, to avoid the risks of redissolving the hydrated UC with too acid pH, generally less than 2, and on the other hand to avoid the risks of formation of compounds.
- the process according to the invention does not have the disadvantages of the processes of the prior art and provides a solution to the problems of the processes of the prior art.
- the process according to the invention makes it possible to prepare uranium peroxide or hydrated uranium peroxide which has a low impurity content, in particular an impurity content which is sufficiently low for this uranium peroxide or peroxide of Hydrated uranium can be converted directly to UF 4 and then to UF 6 .
- the method according to the invention makes it possible in particular to prepare hydrated UC which satisfies totally or in large part the ASTM C-787 standard relating to the purity of the hydrated UC for the conversion to UF6.
- the method according to the invention makes it possible, in addition, to prepare a uranium peroxide which has a high reactivity for rapid conversion to UF 4 .
- the method according to the invention makes it possible to obtain a hydrated UO 4 having a high specific surface area, which can be up to 30 m 2 / g.
- Figure 1 shows the XRD spectrum of the purified uranium powder as U0.2H 2 0 obtained in Example 1.
- FIG. 2 represents the DRX spectrum of the purified uranium powder in the form of U0.2H 2 0 obtained in Example 2.
- Figure 3 shows the XRD spectrum of the purified uranium powder as U0.2H 2 0 obtained in Example 4.
- FIG. 4 is a scanning electron microscope (SEM) photograph of the nanometer needles of U0.2H 2 O of a size of 200 nm obtained in Example 1.
- FIG. 5 is a photograph taken under a scanning electron microscope of U0 4 .2H 2 0 needles with a size of 1 ⁇ to 2 ⁇ , obtained in Example 2.
- Figure 6 is a scanning electron microscope photograph of U0 4 .2H 2 0 agglomerates of size 100 nm to 200 nm, obtained in Example 6.
- an aqueous suspension of a UO3 uranium trioxide powder and / or an U 3 O 8 uranium oxide powder is prepared.
- the process according to the invention can be carried out with all kinds of uranium trioxide UO3 and / or uranium octa-oxide U 3 0 8 , whatever their origin and the form in which they occur.
- These oxides may, for example, be in the form of concentrates called "Yellow Cake”.
- These oxides can also come from the drying and then the calcination of a uranium concentrate based for example on hydrated UC, ammonium diuranate, or uranium tricarbonate by precipitation in a reactor, in particular in a reactor fluidized bed, from a uranium solution.
- the UO 3 or U 3 0 8 powders obtained in this document exhibit, because of the preparation of the uranium concentrate in a fluidized bed, particularly advantageous properties.
- Yellow Cake or oxides from drying and The calcination of a uranium concentrate preferably obtained by fluidized bed precipitation is generally in the form of powders and can be used directly in the process according to the invention, and can be suspended in water.
- the suspended powders generally contain impurities and the method according to the invention is intended in particular to reduce the content of these impurities in the hydrated uranium peroxide obtained.
- a hydrous uranium peroxide whose impurity contents are compatible with its conversion to UF6 and whose impurity levels meet the ASTM C-787 standard.
- the U 3 O 8 powder may contain one or more of the following impurities, for example in the following contents, expressed in ppm / U:
- the UO3 powder may contain one or more of the following impurities, for example in the following contents expressed in ppm / U:
- the reactor used to implement the process according to the invention and in particular to perform steps a) and b) is generally a perfectly stirred reactor generally provided with a propeller stirrer, for example a three-blade propeller.
- the reactor may be further provided with counter-blades or baffles.
- the volume of the reactor can be easily chosen by the skilled person depending on the volume of suspension that it is desired to prepare.
- the reactor may further be provided with sensors and devices for measuring parameter values such as pH and temperature of the suspension.
- the suspension is generally prepared by introducing a known amount of oxide powder (s) into the reactor.
- the amount of demineralized water required to obtain a suspension having the desired concentration is then added to this known amount of oxide. It is obvious that one can also start by introducing demineralized water into the reactor, then add the oxide powder to the demineralised water.
- the concentration of oxide (s) of the suspension is generally from 10 to 500 gU / L, preferably from 100 to 200 gU / L.
- the pH of the demineralized water is adjusted to a value of 2 to 3 by the addition of an acid or a mixture of acids.
- This acid (s) may be any mineral or organic acid.
- an acid is preferred whose anion also has a complexing action which improves the kinetics of the reaction.
- the preferred acids are sulfuric acid, oxalic acid, and mixtures thereof.
- sulfuric acid has the advantage of not introducing disturbing elements with regard to the nuclear purity of UFe because there are no specifications. ASTM on sulfur.
- the rate of conversion to hydrated UO is limited by the formation of a reaction intermediate (uranyl ion UO 2 2+ ) but can be accelerated by the use of at least one complexing anion such as sulphate anion or oxalate anion or the citrate anion, and / or, we will see later, by the application of ultrasound.
- a reaction intermediate uranyl ion UO 2 2+
- at least one complexing anion such as sulphate anion or oxalate anion or the citrate anion
- step a) and / or step b) of the process according to the invention It is therefore possible to add a compound providing this complexing anion during step a) and / or step b) of the process according to the invention.
- the optimum S / U ratio is 0.125.
- Sulfuric acid will preferably be used as the compound providing the complexing anion for suspending the uranium oxide in order to obtain rapid conversion kinetics.
- the powder and the demineralized water having been introduced into the reactor stirring is started to suspend the powder (s) in the demineralized water.
- the stirring speed is adjusted to allow effective suspension of the powder.
- the addition of hydrogen peroxide can be done using any suitable device for controlling the flow of hydrogen peroxide introduced into the reactor.
- the addition of hydrogen peroxide is also preferably carried out with stirring.
- Hydrogen peroxide is generally added in the form of an aqueous solution at a concentration of 30% to 70% by weight.
- the total amount of hydrogen peroxide added is such, according to the invention, that the stoichiometric excess of H 2 O 2 relative to the initial uranium is more than 1 to 10, preferably 1.5 to 3 , with respect to the stoichiometry of the following reaction (1), and more than 1.33 to 10 with respect to the stoichiometry of the following reaction (2):
- the reaction between the oxides and hydrogen peroxide is exothermic and there is, for example, an increase in bath temperature of about 10 ° C.
- step b1) it can be estimated that some conversion to hydrated uranium peroxide occurs, but this conversion is not complete.
- Step b1) can be described as a nucleation step, crystallization, formation of crystallites of hydrated uranium peroxide.
- step b2) the conversion is continued until the conversion of the UC> 3 and / or U 3 0 8 to hydrated UO 4 is total or substantially total, for example greater than 90% or 99.9%.
- Step b2) can be qualified as a ripening step, the growth of the crystallites obtained during step b1).
- the duration of said step b1) can be from 1 to
- step b2) can be 1 to 24 hours, preferably 1 to 3 hours.
- the total duration of steps b1) and b2) is such that the conversion to hydrated uranium peroxide is total or substantially total.
- step b1) no curing step is performed after step b1) and step b2) is omitted.
- the pH generally stabilizes at a value of, for example, 1.6 to 2.
- step b) the conversion to hydrated uranium peroxide being total or substantially total, the precipitate is recovered, the crystals of hydrated UC, generally in the form of tetrahydrate UO 4 , 43 ⁇ 40 or optionally under form dihydrate UO 4 , 23 ⁇ 40, especially in the case where the suspension has been subjected to the action of ultrasound.
- step c) of recovery recover, collect, the precipitated, the UC crystals hydrated by removing the water from the suspension by evaporation thereof, and the precipitate, the hydrated UO 4 crystals, are then recovered in the form of a dry solid, generally a humidity below 7% by weight, generally directly in the reactor without it being necessary to implement liquid / solid separation operation such as filtration.
- the crystals of hydrated UO 4 recovered are in this variant generally crystals of UO 4 , 23 ⁇ 40.
- This first variant is in particular implemented, as described in detail below, in the case where the suspension is subjected to the action of ultrasound.
- step c) of recovery recovering, collecting, the precipitate, the crystals of UO 4 hydrated by separating them from the suspension by a liquid-solid separation operation in the form of a wet solid, for example a moisture of 30% to 80% by weight, also called cake.
- the crystals of hydrated UO 4 recovered are in this second variant generally crystals of U0 4 , 4H 2 0.
- This liquid-solid separation operation may be a filtration operation of the suspension.
- This filtration operation can be carried out under vacuum or by the action of a centrifugal force.
- the collected wet solid can then be washed with a washing liquid.
- Said washing liquid may be deionized water, or an acidified aqueous solution, preferably at a pH of 2 to 3, for example with sulfuric acid.
- washing liquid an aqueous solution, preferably at a pH of 2 to 3, of a complexing anion with respect to the impurities contained in the moist solid such as those already mentioned above.
- Sulfuric acid has the advantage of playing both an acidifying and complexing role through sulphate anions.
- the washing operation may be repeated from 1 to 10 times depending on the desired impurity content of the uranium peroxide.
- the washing ratio defined by the ratio of the mass of the washing liquid (over all the washes) to the mass of the wet solid is from 1 to 30, preferably from 1 to 10, to limit the necessary volumes of water. washing.
- the suspension may further be subjected to the action of ultrasound.
- the ultrasounds used may have a single frequency, but it would be possible to use a combination of ultrasound of different frequencies, for example a combination of high frequency ultrasound with a frequency of, for example, 2.4 MHz, and ultrasound to low frequency with a frequency for example of 35 kHz.
- the reactor containing the suspension can be placed in an ultrasonic tank or arrange one or more ultrasonic probes in the reactor.
- the suspension is generally subjected to ultrasonic action while adding oxygenated water to the suspension. But we can also implement ultrasound during the preparation step of the solution.
- step b) is then only 1 to 2 hours, instead for example 24 hours, to obtain a total or substantially total conversion.
- the suspension is not otherwise agitated.
- the water of the suspension can be removed by evaporation, and the precipitate (the hydrated UC crystals), is then recovered directly in the reactor in the form of an almost dry solid, for example with a moisture of less than 7% by weight and without washing.
- the use of ultrasound thus makes it possible to significantly accelerate the kinetics of conversion and in particular reduces the amounts of water in the hydrated uranium peroxide obtained.
- hydrated uranium peroxide can be recovered without the need for a liquid-solid separation step, such as a suspension filtration step.
- the process according to the invention may optionally comprise a step of drying the recovered hydrated UO crystals.
- This drying step is generally carried out at a temperature of 60 ° C to 100 ° C for a period of 1 to 24 hours.
- the hydrated uranium peroxide recovered is converted to UO 4 23 ⁇ 40 if it is U0 4, 4H 2 0.
- the hydrated uranium peroxide obtained has a high reactivity for rapid conversion to UF 4 .
- a conversion of at least 90% of uranium to UF 4 is obtained in 800 seconds.
- the method according to the invention makes it possible to obtain a hydrated UO 4 having a high specific surface area, which can be up to 30 m 2 / g.
- the conversion rate affects the morphology of the hydrated uranium peroxide obtained by the process according to the invention which is generally in the form of nanometric needles with a length of 300 to 500 nm and a diameter of 50 to 100 nm.
- the needles prepared by the process according to the invention have acicularity expressed by the length / diameter ratio, generally from 3 to 10.
- the levels of impurities in the uranium peroxide obtained by the process according to the invention are, in particular, because the process according to the invention does not comprise a preliminary dissolution step capable of bringing very small additional impurities.
- Table 1 gives the initial levels of impurities in the oxide and final purified uranium peroxide obtained at the end of the process according to the invention.
- the impurity contents of the final peroxide are lower than those of the peroxides obtained by the processes of the prior art and are for the most part in accordance with ASTM C-787.
- the target concentration in the reactor is the target concentration of the reactor.
- the initial sulphate content in the mineral oxide is 24824 ppm / U.
- the reactor used for this precipitation is a perfectly stirred reactor "MSU 700" with a working volume of 700 mL provided with 4 counter-blades and a three-blade impeller, the diameter of these blades being 50 mm.
- the rotational speed of the three-blade propeller is set at 600 rpm to allow the setting effective suspension of the uranium powder. Precipitation of the uranium is carried out at room temperature.
- Various sensors and measuring devices including pH and temperature can track the precipitation reaction.
- the uranium After adding a known quantity of ground oxide powder to the reactor, the uranium is put into stirred suspension in deionized water whose pH is adjusted to pH 3 with sulfuric acid.
- the feed of oxygenated water is then started using a dosing syringe driver to control the flow rate of reagent introduced into the reactor.
- the reaction is exothermic as shown by a 10 ° C increase in bath temperature, and the pH stabilizes at 1.6 at the end of the reaction.
- the washing ratio or "Wash ratio” is 1.6.
- the cake obtained is then dried in an oven at 90 ° C for 24 hours and the dry residue is analyzed. Analyzes of the obtained solid were carried out by X-Ray Diffraction (XRD) (see FIG. 1) and by Scanning Electron Microscopy (SEM) (see FIG. 4).
- XRD X-Ray Diffraction
- SEM Scanning Electron Microscopy
- the XRD analyzes show that the dry residue consists of hydrated UC in the dihydrated form UO 4 .2H 2 O (recognition of the characteristic peaks of the defined compound).
- the SEM photos show that the U0.2H 2 O is in the form of nanometric needles of a length of, for example, 200 nm.
- the concentrations of impurities in the final product show that the process according to the invention has made it possible to significantly purify the starting concentrate. In other words, the process according to the invention has made it possible to eliminate most of the chemical elements present as impurities in the starting concentrate.
- the precipitation of uranium peroxide is carried out under the same conditions as in Example 1 but on the concentrate 2.
- Example 2 The same behavior of the reaction medium is observed as in Example 1, that is to say: exothermic reaction, stabilization of the pH towards 1.6 at the end of the reaction), but the kinetics are much slower.
- the duration of the process until the cessation of stirring which was 7 hours (3h30 + 3h30) in Example 1 is 24 hours in Example 2.
- the moisture content of the hydrated UC cake is greater than in Example 1. This moisture content is indeed 78% instead of 63%. This difference may be related to the size of hydrated U0 needles which are much larger than in the case of concentrate 1 (see Figure 5).
- the molybdenum content is still high compared to the ASTM specification and it does not seem possible to reduce it even if complexing agents favoring the local dissolution kinetics of uranium are used (see examples 3 and 4). .
- Washing with a Wash Ratio of 10 could reach Mo levels close to 10 ppm / U, which could be acceptable in the case of a complementary purification downstream of the process (absorption of impurities in UF 6 ).
- Example 3 Tests on concentrate 3 with addition of sul ates.
- the procedure was modified by adding sulphates to the concentrate to complex the uranium and allow its conversion to hydrated UO.
- the target concentration in the beaker is
- the sulphates are added in the form of sulfuric acid, so that the molar ratio S / U is equal to 0.125 which is the optimum value of this ratio, which corresponds to a concentration of sulphate in solution of 13 g / l.
- the pH varies during the reaction but is generally stable and equal to 2.
- the hydrated UC formed is filtered on filter paper by gravity but is not washed later.
- the uranium content in the filtrate is
- Example 4 Tests on concentrate 4 with addition of oxalates.
- the target concentration in the beaker is
- the oxalic acid is added to the medium so that the molar ratio C2O4 / U is equal to 0.025, which corresponds to a concentration of oxalates in solution of 2.6 g / l.
- the hydrated UC formed is filtered on filter paper by gravity, but is not washed subsequently.
- the uranium content in the filtrate is very high, namely 520 mg / L, and can be explained by the highly complexing character of the oxalate ions.
- Leaks are reduced to 330 mg / L and thus remain almost ten times higher compared to tests carried out without the addition of oxalic acid.
- this treatment does not allow to decontaminate, to eliminate, the following elements: S, V, Zr.
- Example 5 Tests on Concentrate 2 with ultrasound
- Tests were carried out by placing the beaker in an ultrasonic bath (35 kHz) to accelerate the conversion of the concentrate 2 according to the procedure of Example 3.
- This procedure could be optimized (preliminary grinding, injection of an inert gas, high / low frequency ultrasound combinations, control of the temperature by cooling of the reaction medium, increase of the L / S ratio).
- Example 6 we are interested in the conversion of U0 3 .
- Diagram 1 The calcination step of the UO3 impure hydrated unit at 200 ° C. for 3 hours makes it possible to modify the structure of the uranium in order to then be able to purify it more easily from its impurities during the following stages.
- the calcination temperature is a sensitive parameter.
- the second step consists of recrystallizing the UO 3 in hydrated UO 4 according to the initial procedure of Example 1 and then washing the cake obtained with wash ratios ("Wash Ratios" or "WR") higher than previously.
- the washing is carried out using demineralised water whose pH is adjusted to 2.5 with sulfuric acid.
- the choice of the acidity of the pH is guided by the efficiency of the purification in the washing step.
- reaction is exothermic and the pH increases at the beginning of the reaction and then returns to its initial value, which confirms the precipitation hypotheses of the acid-catalyzed hydrated UC according to the following reaction scheme:
- the target concentration in the reactor was 100 gU / L in this example, but other tests were shown that the optimum concentration should be in the range 100 - 200 gU / L.
- This regression is the effect of decreasing the specific surface area of the hydrated UC with the concentration.
- the excess oxygenated water used in this example is the same as in Example 1 but the optimal H2 O2 / U molar ratio is between 1 and 3.
- the moisture content of the hydrated CU cake is 46%.
- the powder is composed of small nanometric agglomerates, for example from 100 nm to 200 nm (see FIG. 6).
- the uranium content in the filtrate is 5.5 mg / L.
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Priority Applications (8)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
BR112013016072-1A BR112013016072B1 (pt) | 2010-12-24 | 2011-12-16 | processo de conversão de uo3 e/ou de u3o8 em uo4 |
GB1310642.2A GB2502204B (en) | 2010-12-24 | 2011-12-16 | Method for converting UO3 or U308 into hydrated UO4 |
CA2822448A CA2822448C (fr) | 2010-12-24 | 2011-12-16 | Procede de conversion d'uo3 et/ou de u3o8 en uo4 hydrate |
EA201300752A EA024219B1 (ru) | 2010-12-24 | 2011-12-16 | Способ превращения uoили uoв гидратированный uo |
CN201180062581.6A CN103402909B (zh) | 2010-12-24 | 2011-12-16 | 使uo3和/或u3o8转化为水合uo4的方法 |
US13/995,277 US9045350B2 (en) | 2010-12-24 | 2011-12-16 | Method for converting UO3 or U3O8 into hydrated UO4 |
AU2011347672A AU2011347672B2 (en) | 2010-12-24 | 2011-12-16 | Method for converting UO3 and/or U3O8 into hydrated UO4 |
ZA2013/04223A ZA201304223B (en) | 2010-12-24 | 2013-06-10 | Method for converting uo3 and/or u3o8 into hydrated uo4 |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
FR1061249 | 2010-12-24 | ||
FR1061249A FR2969659B1 (fr) | 2010-12-24 | 2010-12-24 | Procede de conversion d'uo3 ou de u3o8 en uo4 hydrate. |
Publications (1)
Publication Number | Publication Date |
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WO2012084740A1 true WO2012084740A1 (fr) | 2012-06-28 |
Family
ID=44312285
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/EP2011/073132 WO2012084740A1 (fr) | 2010-12-24 | 2011-12-16 | Procédé de conversion d'uo3 et/ou de u3o8 en uo4 hydraté |
Country Status (10)
Country | Link |
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US (1) | US9045350B2 (fr) |
CN (1) | CN103402909B (fr) |
AU (1) | AU2011347672B2 (fr) |
BR (1) | BR112013016072B1 (fr) |
CA (1) | CA2822448C (fr) |
EA (1) | EA024219B1 (fr) |
FR (1) | FR2969659B1 (fr) |
GB (1) | GB2502204B (fr) |
WO (1) | WO2012084740A1 (fr) |
ZA (1) | ZA201304223B (fr) |
Families Citing this family (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR2976281B1 (fr) | 2011-06-09 | 2014-06-13 | Comurhex Soc Pour La Conversion De L Uranium En Metal Et Hexafluorure | Utilisation d'un compose kmgf3 pour pieger des metaux presents sous forme de fluorures et/ou d'oxyfluorures dans une phase gazeuse ou liquide |
FR3017611B1 (fr) * | 2014-02-19 | 2016-03-18 | Areva Nc | Procede d'activation de l'u3o8 en vue de sa conversion en uo4 hydrate. |
CN106629854B (zh) * | 2016-10-20 | 2017-12-15 | 核工业理化工程研究院 | 微波加热硝酸铀酰溶液生产三氧化铀的方法 |
CN110921710B (zh) * | 2019-11-25 | 2022-05-03 | 南华大学 | 具有光催化降解环丙沙星活性的铀氧化物的制备及应用 |
CN113023781A (zh) * | 2019-12-24 | 2021-06-25 | 中核建中核燃料元件有限公司 | 一种高活性粉末的制备方法 |
FR3107587B1 (fr) * | 2020-02-25 | 2022-06-10 | Orano Cycle | Procédé de stockage et de libération d’énergie thermique par voie thermochimique |
CN111394741B (zh) * | 2020-03-25 | 2022-04-05 | 哈尔滨工程大学 | 一种氟化u3o8或uo3并溶于氯化物熔盐的方法 |
CN112707444A (zh) * | 2020-12-10 | 2021-04-27 | 核工业北京化工冶金研究院 | 一种含铀硫酸铵溶液制备铀氧化物的方法 |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR2429747A1 (fr) | 1978-06-27 | 1980-01-25 | Gardinier Inc | Procede pour purifier le tetrafluorure d'uranium hydrate et preparer le peroxyde hydrate d'uranium-vi |
EP0054014A1 (fr) * | 1980-11-24 | 1982-06-16 | FMC Corporation | Procédé d'élimination des impuretés en phosphore du gâteau jaune |
WO2009013759A1 (fr) | 2007-07-24 | 2009-01-29 | Secretary, Department Of Atomic Energy | Purification à un seul stade pour le raffinage de l'uranium |
WO2010051855A1 (fr) | 2008-11-07 | 2010-05-14 | Areva Nc | Procede de preparation de concentres d'uranium par precipitation en lit fluidise, et preparation d'uo3 et d'u3o8 par sechage/calcination desdits concentres. |
Family Cites Families (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2723181A (en) * | 1955-05-26 | 1955-11-08 | Clarence E Larson | Processes of producing uranium trioxide |
FR2959565B1 (fr) | 2010-04-28 | 2012-06-08 | Commissariat Energie Atomique | Procede de test d'etancheite non-destructif d'un electrolyte de cellule electrochimique |
-
2010
- 2010-12-24 FR FR1061249A patent/FR2969659B1/fr active Active
-
2011
- 2011-12-16 BR BR112013016072-1A patent/BR112013016072B1/pt active IP Right Grant
- 2011-12-16 WO PCT/EP2011/073132 patent/WO2012084740A1/fr active Application Filing
- 2011-12-16 GB GB1310642.2A patent/GB2502204B/en active Active
- 2011-12-16 EA EA201300752A patent/EA024219B1/ru not_active IP Right Cessation
- 2011-12-16 US US13/995,277 patent/US9045350B2/en active Active
- 2011-12-16 CN CN201180062581.6A patent/CN103402909B/zh active Active
- 2011-12-16 CA CA2822448A patent/CA2822448C/fr active Active
- 2011-12-16 AU AU2011347672A patent/AU2011347672B2/en active Active
-
2013
- 2013-06-10 ZA ZA2013/04223A patent/ZA201304223B/en unknown
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR2429747A1 (fr) | 1978-06-27 | 1980-01-25 | Gardinier Inc | Procede pour purifier le tetrafluorure d'uranium hydrate et preparer le peroxyde hydrate d'uranium-vi |
FR2438623A1 (fr) | 1978-06-27 | 1980-05-09 | Gardinier Inc | Procede de purification du peroxyde hydrate d'uranium vi |
EP0054014A1 (fr) * | 1980-11-24 | 1982-06-16 | FMC Corporation | Procédé d'élimination des impuretés en phosphore du gâteau jaune |
WO2009013759A1 (fr) | 2007-07-24 | 2009-01-29 | Secretary, Department Of Atomic Energy | Purification à un seul stade pour le raffinage de l'uranium |
WO2010051855A1 (fr) | 2008-11-07 | 2010-05-14 | Areva Nc | Procede de preparation de concentres d'uranium par precipitation en lit fluidise, et preparation d'uo3 et d'u3o8 par sechage/calcination desdits concentres. |
Also Published As
Publication number | Publication date |
---|---|
CN103402909A (zh) | 2013-11-20 |
US9045350B2 (en) | 2015-06-02 |
ZA201304223B (en) | 2014-07-30 |
CA2822448C (fr) | 2019-01-22 |
GB2502204A8 (en) | 2013-12-18 |
GB201310642D0 (en) | 2013-07-31 |
GB2502204A (en) | 2013-11-20 |
EA024219B1 (ru) | 2016-08-31 |
FR2969659A1 (fr) | 2012-06-29 |
AU2011347672B2 (en) | 2016-01-14 |
FR2969659B1 (fr) | 2013-02-08 |
US20130280157A1 (en) | 2013-10-24 |
EA201300752A1 (ru) | 2013-11-29 |
GB2502204B (en) | 2018-12-26 |
CA2822448A1 (fr) | 2012-06-28 |
BR112013016072B1 (pt) | 2020-12-29 |
CN103402909B (zh) | 2017-09-26 |
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