JPS58501994A - Refining of uranium-containing concentrates - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] Refining of uranium-containing concentrates Non-inventive materials include uranium-containing materials, especially those containing zirconium and/or... Concerning the method for refining concentrate. The method of the present invention first involves introducing an acidic agent in a strictly controlled amount. Therefore, the uranium-containing concentrate is treated and then treated with hydrogen peroxide to remove impure uranium peroxide. The first step is to fix the shape, and the non-conforming uranium phase obtained in the first step is treated with an acidic agent. The second step is to ensure that the refined uranium-containing coffin is obtained through processing and a new texture. Included as

Uranium-containing concentrate is an undesirable presence when making the final face of uranium. To have or to have the possibility of containing a number of different words 1 is limited.

In the treatment of the above-mentioned slimy uranium-containing concentrate, usually two valves 1. Jin Niyun 1- ・Masashi) lower −≧zo Inject uranium in the form of uranyl salt, then use all sensitizing hydrogen to escape. Uranium in the chemical O state? For specialized roses that are produced by precipitation, the above-mentioned treatment is described, He explains that it is unwise to obtain a sufficiently refined uranium compound because there are undeliverables. Ru.

Most commonly used in the treatment of furan-containing concentrates. l'he extractive rvletallurgy of Ura: 1ix” 1971 moves.

Colorado School of Mine Research Institute.

Pages 247-248, and “Proceeding of the Intsrna-tional Conference on the Paa ceftxl uses of, Atomic ErLergy” UK, 14 Volume, pages 141-143 (1955) E, L, Z I#Ib1 ER(D''　Per5ation as an IR phase in the chemical purification of crude uranium-containing products Uranium Production Separation”.

According to these papers, when precipitating uranium in an impure solution containing uranium Although it is possible to maintain the existing state of non-punishment and general understanding, it is possible to obtain The uranium-containing precipitate contains a non-negligible amount of impurities when the precipitate is separated. This fact remains true even after a long period of post-washing.

90. According to the precipitation and washing of uranium peroxide, silver, arsenic, arungan, molyb Non-N such as den, vanadium, sodium, nickel, antimony, tin, zinc ’aH can be sufficiently removed, but iron, phosphorus, and silicon require separate purification treatment in advance. Unless implemented 9 sufficiently reasonable removal is ensured! 1. do not have.

The uranium-containing concentrate may also contain other impurities such as zirconium and/' or/. These impurities are usually removed when aqueous solutions containing them are treated with hydrogen peroxide. It precipitates at the same time as uranium when it is extracted. Therefore, from the obtained superstructured uranium, cedar It is not possible to obtain sufficiently pure uranium for energy use.

Improvements to the above-mentioned conventional treatment methods for uranium-containing concentrates are also described in specialized texts. It is listed. These methods require a uranium-containing water bath solution containing all leached impurities at the same time. ) until the use of superimposed X element to precipitate uranium peroxide; The methods for removing the above specific impurities are different from each other.

For example, νf, 5HABBIR and 'Rep' by E-TA:viE ort of InvestigationOns 7931 of US Bur eau of:! "Uranium produced by hydrogen peroxide" listed in "Viines 1974" In the "precipitation", molybdenum impurities, vanadium impurities, An acidic aqueous solution of uranium is heated at room temperature using hydrogen peroxide to bring the pd of the solution to a range of 3 to 6. Describes a method for producing uranium peroxide, which is processed over a period of 4 hours while adjusting to various values of I'm here. In this paper, the authors obtained a fully N-made uranium peroxide precipitate. It clearly states that it is necessary to maintain the pH'i of the bath solution between 3.5 and 5.

The method described above may contain special impurities such as zirconium and/or hafnium. When used in impure uranium-containing concentrates, these special impurities are When the element is introduced, it precipitates with uranium, so in the end only 2 impure degenerates are produced. Another method that is more advanced with respect to impurities present is disclosed in U.S. Pat. No. 2,777. No. 0,521, this method is used to treat sulfuric uranyl solutions. First, adjust the pH of the solution to 3 to 4 using calcium carbonate to remove iron, @, and chlorine. cobalt, nickel.

Precipitate the impurities such as manganese and molybdenum, then separate the impurity precipitate. Hydrogen peroxide was completely introduced into the uranium-containing bath liquid with reduced impurities, and the temperature of the precipitation medium was raised to 9. Precipitate uranium peroxide from solution by maintaining pH 2.5 to 3.5 below 65°C Forbidden.

The uranyl sulfate bath solution to be treated contains not only ordinary waste and by-products, but also zirconium and/or or also contains impurities consisting of hafnium, the method may be less advantageous. Conceivable. With Tsutsukai, it is used for charcoal calcium to selectively deposit disadvantageous materials. This method reduces the concentration of 5O2- ions in uranium-containing solutions and as a result a part of uranium, zirconium and/or nitride and impurities to be removed. This is because coprecipitation is likely to occur, resulting in a non-negligible loss of uranium.

Additionally, zirconium and/or hafnium may not partially precipitate with the swordsmiths. Inode is precipitated with the remaining 9 parts of uranium peroxide after bathing in the uranium-containing liquid. Let's go.

Therefore, the method of the prior art proposed to Todoroki is that the uranium-containing liquid is mixed with a concentrate using a solubilizing agent. If the product is obtained by leaching, there may be impurities such as zirconium and/or halide present in the product. It cannot be a fully satisfactory solution because it contains funium.If the number of cases is During processing, uranium and special impurities such as those mentioned above will co-precipitate. Therefore, in order to obtain the consistency necessary for nuclear energy use, uranium peroxide must be purified later. You need to do it, so you can do it.

In this way, the proposed process cannot satisfy the user's request. As a result of research, the applicant has obtained a uranium-containing liquid that does not have the above-mentioned drawbacks and is extremely pure. We have successfully discovered and constructed a method for refining uranium-containing concentrate.

An unnatural thing? Contains silconium and/or hafnium. Refining uranium-containing MN ore containing at least one of the elements constituting the group consisting of The inventive method of producing... The treatment of the concentrate by fertilization in a sex probe is recommended.

The feature of the uninvented method is that in the first step, uranium is precipitated to a constant concentration of 1 FFJ to eliminate impurities. For the purpose of leaching all or part of the Waran Kogou concentrate, it is impregnated with an entirely aqueous medium Next, E1 was carefully and selectively acidified using all the detergents mentioned above, and the obtained alcoholic acid was Primarily uranium, zirconium and/or A precipitate containing almost all of hafnium is formed, and a liquid phase containing all impurities of the precipitate Then, in the second step, the precipitate obtained in the first step is treated with an acidic agent. treatment to convert uranium into soluble uranyl ions and elute them. liquid phase containing all zirconium and/or hafnium-containing compounds. The solid uranium-containing material treated by the method of the present invention can be 8 翿'r1 was obtained by the well-known hydrometallurgical treatment of uranium-containing ores. It is something. These products usually consist mostly of furan with a large proportion of impurities, e.g. For example, silver, arsenic, aluminum, bismuth, calcium, magpsium, manganese , molybdenum, vananium, sodium, niggle, anti-tin, tin and especially The group formed from zirconium and/or hafnium is the metal that constitutes it. Stone the state of a solid mixture consisting of at least one building.゛Processed by an uninvented method Liquid uranium-containing Yoshimine 12: Same impurities as those present in solid uranium Miya ore. Glue formed from 29, special K, zirconium and hafnium containing impurities It contains at least one amount of metal that makes up the group.

In the first stage of processing, if the uranium-containing concentrate is solid, the concentrate 7 is dispersed in an aqueous medium maintained under stirring to obtain a suspension that is treated with an acidic agent. . An acidic agent is then slowly introduced into the impregnating solution to remove most of the uranium and impurities present. Both of them are exuded. Gradual introduction time of acidic agent lrJ, usually 5 to 200 minutes time, but in particular 10 to 120 minutes. Determined as impurity H + Todoroki 1 determined.

One of the acidic agents to be introduced at the time of preparation is an alkaline acid and/or an equivalent acid. The amount of acidic agent to be introduced in the first step of the non-inventive method is determined for The stoichiometric amount of the above-mentioned kachiman τ-・10;ノ/) Oil'-'l An amount in the range 1.1 to 7 is used. Actually, it is necessary to introduce The amount of acidic agent used should be such that the concentration of free H after acidification is at least 0.01N Soul -0-, -1 praise, preferably at least 0. Selected to be IN. cormorant The amount of acidifying agent introduced into the aqueous suspension of orchid-containing concentrate is therefore The body is maintained in an aqueous suspension or, in some cases, in the form of a slightly turbid liquid. exhibit evil. In the latter case, the liquid is initially present in the uranium-containing concentrate and It has most of the uranium and all of the uranium in a molten state.

Regardless of whether the acidified medium obtained is a suspension or a solution, the temperature of the medium is adjusted to be maintained at 70°C or below.

Preferably the temperature is maintained in the range of 30°C to 40°C.

When the uranium-containing concentrate is in a solution state, the solution is subjected to the same acidification treatment as solid concentrate. Do this.

The acidified aqueous medium, maintained at the desired temperature after the acidification process, is then treated with hydrogen peroxide. Ru. Hydrogen peroxide has a low stoichiometric amount required to precipitate only uranium peroxide. is also introduced into the medium in an amount equal to twice as much.

The amount of hydrogen peroxide is at least 1.4 times the stoichiometric amount required for precipitation of uranium peroxide. , in particular 2 to 3 times the stoichiometric amount. This is a concentrate containing silarane. A group formed from zirconium and hafnium that was first present in An impurity consisting of at least one element belonging to uranium is changed into a constitutive state and maintained. It will be done.

Converting uranium and at least one kind of zirconium element and hafnium element into isoforms As is well known to those skilled in the art, the maintenance treatment is usually carried out at a pH of λ5 to 4.5. It will be done.

pH is an alkali such as sodium hydroxide, potassium hydroxide or ammonium hydroxide. regulated by the introduction of softening agents.

After introducing hydrogen peroxide into the acidifying medium where the temperature and pH are maintained at selected values, this The suspension obtained in the treatment is subjected to an aging treatment. In the aging process, suspension was first selected The temperature is maintained under stirring for up to 6 hours, preferably from 2 to 4 hours.

The suspension after this final aging treatment is subjected to solid-liquid separation treatment.

This treatment may include filter aids such as Ki≦se1gure, diatomaceous earth, if necessary. This can be done by means known to those skilled in the art, such as filtration, decantation, centrifugation, etc. minutes The solid phase obtained after separation is treated with a sufficient amount of water or 0.2% peracid to derive the solid phase impregnating solution. Washed with an aqueous solution of hydrogen chloride.

As an example of a hairstyle that can be applied to the first stage, regardless of the uranium-containing concentrate used, Haruka Fluoride acts as a complexing agent to obtain a uranium-containing liquid with good reproducible purity. The acidified aqueous medium is treated using an ion source. For this variant, the resulting medium Regardless of whether the medium is in suspension, solid or solution, the temperature of the medium is at least acidified aqueous medium adjusted to be maintained at 70°C, preferably maintained at 90°C; is then treated with a fluoride ion source. This C ion source, for example, Compound i (F, NaF, KF, NH4F) that can elute almost all of , Na25t, F6a> and can be used alone or as a mixture. complexing agent is such that the molar ratio F/(Zr + Hf) is at least equal to 1 and preferably from 4 to 10. amount is introduced into the acidified aqueous medium.

The temperature of the aqueous medium in which the complexing agent is introduced is at least 70°C, preferably 90°C to Maintained at 100°C. Introduction of the complexing agent into the acidified medium where the temperature is maintained at a selected temperature. After the addition, the solution obtained by this treatment is subjected to an aging treatment. In the aging process, the number of baths is maintained under stirring for no more than 6 hours, preferably from 1 to 4 hours, within a temperature range selected for . Aging treatment Temporarily immersed in an aqueous solution of the female body at a temperature lower than 60°C, preferably 30°C Cool to a temperature between 40° C. and then treat with hydrogen peroxide. Hydrogen peroxide is too much The amount of said medium is at least equal to the amount necessary to precipitate only uranium chloride. introduced into the body. In particular, amounts of 2 to 10 times the stoichiometric amount are used. cooled After introducing all the super-yielded element into the medium, sodium hydroxide was added to the suspension obtained from this treated air. pH is adjusted by introducing an alkaline agent such as electrolyzed potassium or ammonium hydroxide. The wheel is pulled loosely to a selected value in the range of 2.5 to 4.5. Suspension after pH adjustment is then kept under stirring at a temperature below 60° C. for up to 6 hours, preferably from 2 to 4 hours. and ripening process.

The separated and washed solid phase after the first stage is uranium peroxide and at least 51 types of zirconium. A liquid formed from a precipitate containing compounds and/or non-funium compounds. Phase ζ contains substantially all of the other impurities in the dissolved state.

In the second stage of processing, the homophase containing mainly uranium obtained in the first stage is ’# Treated and then applied with the original paste form or with water or recycled liquid. After soaking it in an aqueous medium, it is treated with an acidic agent.

In the second step, the uranium is introduced into the solid phase in situ or in aqueous suspension. The amount μ of acidic agent used corresponds to the amount that causes only the elution of the uranium present in the phase.

The uranium-containing phase in its original state or in liquid suspension is subjected to the action of acidic agents. It may be heated to a temperature of 60 to 100°C or 85 to 95°C before heating. . It is preferable to heat the solution after introducing the acidic agent. In the latter case In order to prevent gas generation from dissolving uranium, the temperature is increased.

Selection of the scope of uranium dissolution treatment This completes the process. This process usually requires at least an hour or <3 to 5 hours are required.

The suspension obtained after bathing and aging usually contains zirconium and/or Hafnium compounds are cooled to a temperature of 40℃ or less, which reduces the degree of oxidation. . Next, the suspension is subjected to layer separation treatment, and the purified liquid rich in uranium is collected and converted into zirconium. The same phase containing a compound and/or a compound consisting of a hafnium compound can be removed.

The acidic agent used in each of the first and second stages of the method of the present invention is sulfur, sulfur, and salt. It may be selected from the group consisting of acids and hydrofluoric acids. Same acidity in two stages Although different acidic agents may be used, preferably different acidic agents are used and more than one acidic agent may be used. Preferably, it consists of a mixture of.

As described above, the feature of the method of the present invention that stands out from the prior art is that impurities are removed in the first step. The main part is eluted and removed, and the characteristics of the second stage are those obtained in the first stage. Only the impure uranium is dissolved and the final undesirables are removed in solid form.

In fact, the so-called method for producing uranium-containing pyrite according to the present invention includes the following treatments: These processes may be continuous, and may be performed discontinuously.

a) Suspending the uranium-containing ore in an aqueous medium maintained in an agitated state; or km of the uranium-containing liquid to be treated; b) maintaining the stirred medium at a suitable temperature; 9. Introducing an adjusted amount of acidic agent; C) Adjust the pH of the aqueous medium obtained in step b) to a range of 2.5 to 4.5 and add peracid. an amount of peroxide equal to at least twice the stoichiometric amount required only for the precipitation of chlorinated furan; introducing hydrogen into the aqueous medium; d) Stirring for up to 6 hours under the temperature and pH conditions selected in steps b) and C). Aging the suspension obtained in step C) by maintaining e) A liquid containing eluted impurities and a phase containing mainly uranium in the form of chloride. to separate the f) washing the same phase obtained in step e); g) aqueous door body made from water or recycled liquid; suspending the uranium-containing homophase in 'rL) The uranium obtained in step g) is a chemical theory that flows into the uranium present in the suspension liquid A. Acidic agent below the required amount: / Koyo Shiwaran Zenrakukaizo, heat before acidification or during dispersion. do, l) Full ripening of the slurry served in step n) by stirring for at least 1 hour at the selected temperature. do, J) Cooling the suspension obtained in step l) to a temperature below 40"C; k) F4 A compound consisting of a liquid contained in orchid and a zirconium compound and/or a zirconium compound and/or a zirconium compound. Separate the pure-hearted prick from the monotonous face.

According to a variant, steps c and d are carried out immediately below.

b) Maintain the stirred medium at an appropriate temperature and introduce a suitable amount of acidic agent. bl) Keep the medium at an appropriate temperature and loosen the complexing agent consisting of a fluoride ion source in a controlled amount. electrification of non-creative power by introducing '1) 2) The medium obtained in step b1 was heated to a temperature range of 100 to 100 ml in steps a) and b). The original is matured by stirring for less than 6 hours under the b3) cooling the medium obtained in step b2 to a temperature below 60”C; C) The chemical amount required for precipitation of uranium peroxide only in the aqueous medium obtained in step 1 b3. introducing at least an amount of hypohyperoxide peroxide, C1) Support the pt of the medium served in step C) until it reaches a range of 2.5 to 4.5. <adjust with p, d) The suspension obtained in step cl is subjected to the selected temperature conditions and in steps b3 and cl. The suspension is matured by cutting it into pieces of not more than 6 square meters under the same conditions.

A schematic diagram VC showing the two stages of the non-inventive method and its variants is shown below with accompanying symbols throughout. The present invention will be more fully understood from the description below.

According to FIG. 1, uranium-containing concentrate Sl is suspended in an aqueous medium in a container. aqueous medium The body consists of a mixture of recycled liquid L□3 and L□3 and is maintained under stirring.

The suspension L1 obtained as described above is then freed from the impurities originally present in the uranium-containing Toshige. Acidic acid which is said to be mild in (B) in order to completely leached out all or part of the pure substance. Treatment 6i with agent L20.

During this time, the temperature of the medium is adjusted to 80° or less.

When the temperature is maintained under stirring, it becomes hostile and becomes cloudy. is 'C) 7. Temperature and p H and can be treated with an aqueous hydrogen peroxide solution.

The active amount of hydrogen peroxide is at least 1.0% of the stoichiometric amount required for the formation of uranium peroxide. Equal to 4 times.

The suspension L3 of uranium peroxide obtained in FC) is subjected to aging treatment.

The aging process consists of discarding the remaining liquid under stirring at a temperature range of 6 to 1 liter.

After the aging treatment, solid-liquid distribution treatment is performed on the suspension L4 containing the liquid, resulting in a liquid containing liquid L4. 5 and uranium VX, which was originally present in the uranium minerals, almost all ft zirconium and/or a cake S containing hafnium irregularity and a certain amount.

Next, in (F)Y, the cake S is washed with water-soluble fLLi23 and the cake s5 is impregnated. Was it impure? A liquid LI3 for deriving Jt and a cake s6 are obtained.

Liquids L5 and L6 are mixed to form liquid L□4. A part of L□4 and □5 is (3 ), and the remaining portion L□6 is subjected to processing cycles 〃1 and so on.

Cake S6 was suspended in aqueous reuse liquid L□8 during the season, and the resulting suspension L7 is then turned into an enemy by the setting fluid L24 in the tank. The amount of acid in liquid L24 is Compatible with elution only. The suspension is then heated to a temperature of up to 100°C. .

The obtained suspension L8 is heated in (I) at a temperature equal to the temperature used in (■) at least Aged for 1 hour.

Obtained after aging treatment. @Turn the turbid liquid L9 into uranium by separating it and convert it into UNR liquid L□.

and mainly formed from zirconium compound and/or hafnium compound moving blade. A precipitate Slo is obtained.

The precipitate S1o was then washed with aqueous liquid L25 at VtC■, and ? itL, □ and real A cake S□1 containing no uranium is obtained.

Uranium-containing liquid L1o and L□□ are mixed to obtain liquid L□7. Part of αL□7 □8 is reused in (G). The remaining portion L□9 is used as a bill for uranium modification fluid.

Repulping with water εiL, 6 in Cake S□□Bahej e) The treated solution L12, which is suspended and produces a night-time process 2, is h) treated in a solid box for 1 minute at K. receive.

Consisting essentially only of zirconium impurities and/or hafnium impurities. The solid S□3 is removed from the processing cycle and the liquid S□3 is reused in the prison.

According to Figure 2, which shows the hairstyle method, uranium-containing Seifu S□ is suspended in an aqueous medium in prison. It becomes cloudy. The aqueous medium is recycled liquid L□3 and L□.

It is composed of a mixture of 2ρn and 2ρn while stirring.

Obtained as described above. Suspension liquid L1ΣNext, in IBI, the uranium-containing reconcentrate A Loosen the acidic agent L20 by leaching out all or some of the impurities that were initially present. Introduce and process. During this time the temperature of the medium is adjusted to at least 70°C.

The hostile suspension L2 was stirred at the above temperature (BA) and then fluorinated. It is treated using a complexing agent consisting of gold (ion source).

A complexing agent L45 is introduced as ρ, which thickens in a controlled amount.

The aqueous medium L4□ obtained by the complexation is at (bB) at the initial selected temperature of the medium. The product is subjected to a processing operation in which it is unloaded under stirring for less than 6 hours.

After the aging treatment, the suspension L42 (all CBC) is discharged and cooled at a temperature of 1.

Suspension L43, maintained under stirring at said temperature, is peroxidized in CC) at a controlled temperature. After introducing hydrogen, process with L2□. The active amount of hydrogen peroxide is necessary for the formation of uranium peroxide At least equivalent to a chemist.

Solution L22 was introduced into the uranium peroxide suspension L3 obtained in (C) in (CA). Adjust the pM to a value between 2.5 and 4.5.

The optimized uranium suspension L44ζ obtained in (CA) is then first selected in (2). subjected to an aging treatment maintained under stirring at a selected pH and temperature range for up to 6 hours; .

The suspension L4 obtained after the aging treatment is optionally treated with a chemical 846 that is advantageous for solid-liquid separation. After solid-liquid separation treatment, the impurity-containing liquid L5 and the uranium-containing liquid L5 were initially present. Almost the entire amount of uranium was mixed with zirconium impurities and/or -fnium impurities. We obtain cake S, which contains .

Cake S5f: Next, burn it in the town and clean it with aqueous solution L23 to impregnate cake S5. A liquid L6 and a cake S6 are obtained.

The liquid and L6 are mixed to form 1L14t. Part of the liquid L engineering is in (3) It is returned and reused, and another portion L□6 is sent to the processing cycle.

Cake S6 is suspended in reused X liquid L□8 in G), and the resulting suspension L7 is then acidified by acidic liquid L24 at 0 . The amount of acid is only for uranium elution corresponds to The suspension is then heated to a temperature of up to 100''C.

Obtained. ε hot liquid L8 is at least 1 at a temperature equal to the working temperature of the surface at (I)K. Subjected to the aging process of time.

Optionally, a chemical S4□, which is advantageous for separation, is added to the suspension obtained after the aging process. The partially dissociated uranium-rich purified liquid L1o and mainly zirconium compounds and/or Alternatively, a precipitate S1o formed from a no-phnium compound is obtained.

The precipitate SIO is then washed with aqueous liquid L25 in a wholesaler to remove substantially all of the uranium from liquid LL1. We get a cake S that does not contain □.

Mix uranium-containing liquids L and L to obtain liquid 7. Liquid L engineering.

011 Part L is reused in C), and the remaining part L is back 8 It corresponds to Yuzo liquid.

Cake S is repulped using riC liquid L26 as the axis to obtain a slurry liquid L. 12 was obtained and subjected to solid-liquid separation treatment in liquid L1-south.

Solid S consisting essentially only of zirconium impurities and/or hunium impurities □3 is removed from the processing cycle and liquid L□3 is recycled in (A).

The invention will be more fully understood through examples showing the scope of the invention.

Example 1 This example is based on the actual instructions carried out in CD) after the introduction of hydrogen peroxide in the first stage. to the quantity H11, in order to show the importance it has on the precipitation efficiency of uranium in peroxide form. It was done.

For this, 200 I of ammonium uranate concentrate was suspended in 200 J of water. . The ammonium uranate concentrate had the following weight percent composition:

U: 61.16% Mo: 0.39 person Zr: 133% NH4”: 4.7g% Others: 32.34% 3. To the suspension formed as above. 100% HNo of OI = and 57g of 100 JH, O, were added sequentially over 20 minutes. The pH value of the medium was adjusted to 3 and the suspension was The temperature of the liquid was maintained at 35C = the effect of aging time was on the results shown in Table I below. This can be confirmed by consideration. Table I shows that after the cake is separated and cleaned, it is not poisonous and the original ripening It is shown as a function of the time devoted to processing.

After the introduction of hydrogen peroxide into the acidic suspension, various treatments separated by 30 minutes from O to 4 hours. Six tests were conducted corresponding to the times of .

Table 1 The table shows that an aging time equal to at least 1 hour is required for the leached uranium to completely precipitate. Indicate that it is necessary.

Example 2 In this example, the uranium contained in the uranium peroxide obtained in the first step was completely dissolved. The effect of the amount of acidic agent introduced in the second stage to achieve this effect can be shown.

Two tests were conducted by changing the amount of acidic agent introduced. The effect of the amount of acidic agent introduced is shown in the table. This is clear from the results shown in (2).

To this end, the first stage of the process is carried out using the uranium-containing concentrate defined in Example 1. to form a wet cake S6, which is then treated in the second stage of the method of the invention. did.

Each test used 20,011 pieces of cake S6 formed from impure uranium peroxide. did.

According to this table, the free acidity is 0. When 2NK changes from IN, the degree of birth of impurity Zr is about 4 It becomes 0 times. This means that the uranium-containing precipitate obtained in step 81 can be completely dissolved by dissolving it. This indicates the need for tight control of the amount of acid introduced.

Example 3 This example describes the process of dissolving uranium from the precipitate obtained in the first stage. The reason why the duration of the two-stage aging process (I) is important will be clarified.

For this purpose, the same amount of the substance to be treated (200I) as in Example 2 (Test) (G) and the Five consecutive tests using physical substances (100% HNO3 of 39,65,!i’) We conducted a test. In each test, the acidic suspension g, was maintained at 90C under stirring and the test The maintenance time was changed each time. The test result is the Zr concentration in the aqueous phase collected after aging separation. As shown in Table 1, it is necessary to ripen for at least 2 hours, especially about 4 hours. Show that. When such aging time is used, the behavior of impurities Zr and Mo is within the measurement range. maintained within the surroundings.

Example 4 (based on Figure 1) This example describes a method of the invention that includes a two-step process.

According to the method of the present invention, in the first stage of the treatment, the dry state has the following weight percent composition: Suspended 200M parts of uranium-containing concentrate with Mo 0.39% Other than that +HzO: 32.34% 200 parts by weight of water are introduced into said zone (A) and then necessary to obtain a homogeneous suspension. The mixture was stirred for a period of time. To this suspension was added an amount equivalent to 30 parts of 100% HNO3 over 20 minutes. It was a long day (Zone B). The suspension obtained above was then treated with 57.0j9 H Add 2O, (100%) (L21) in 20 minutes to zone C), aqueous dispersion na The pH was adjusted to 3 by adding thorium (L22). Suspension coming out of zone (C) A ripening treatment in which the suspension is kept under stirring at a temperature of 35C for 2 hours and 30 minutes. was carried out in (D). The suspension L4 obtained in (D) is then processed in (E). After separation treatment, liquid L5 and the same phase S6 were obtained.

The surface phase S5 was then treated with 200 parts by weight of water in (F), and the liquid L after washing was 6 and solid phase S6 were obtained. *Liquid L14 was obtained by mixing Ls and L6. Liquid L+4 A part of LI5 is reused to suspend uranium-containing concentrate in LI5, The residual portion Llfl is removed from the cycle to avoid the accumulation of impurities in the first stage. Served.

Liquid L14 had a weight composition of 323 parts by weight or less.

NH4NO3: 12.9% N a NO3: 1.7% H20+Other: 80.05% Therefore, 90.0% of the molybdenum initially present in the uranium-containing concentrate is Removed by 14.

K48 after cleaning (F). was 349 parts by weight wet cake. 60iC After drying at Person in charge In the second stage of the treatment according to the invention, the cake S6 obtained in the first treatment stage is ( 65 copies of 100% HNO in H)! Processed with. This acid will loosen in 20 minutes The resulting suspension was heated to 90C in (I). and maintained at this temperature for 4 hours.

The suspension L9 coming out of zone CI) is separated in (J) to form liquid Lto and cake St. I got O. Cake StO was washed with 22 parts by weight of water (Lzs) in (K). , cake S□1 and liquid Lu were obtained. Construct liquid LIT by mixing liquids L1o and Lll. accomplished. Liquid L17 was 450 parts by weight.

This liquid L17 had the following composition.

U: 27.2% Mo: 0.016% Zr: 0.005% &O 1 NO3 + other 2.779% purified liquid L17 is part of CG) The cake S6 obtained in the first stage is reused to suspend it, and the remaining cake is Part Lt.

constituted the uranium production liquid. Cake S11 after drying at 60U is 5.6 parts by weight The weight was .

The cake contains substantially 99% of the zirconium originally present in the uranium-containing concentrate. ．． The uranium concentration is 0.1% of the uranium originally present in the concentrate. The amount represented a loss of 4%.

In the case of a continuous process, this loss was resuspended in weakly acidic liquid L- in CM). . After filtration with (N), liquid L26 is reused as liquid L13 in (A).

Example 5 In this license, a method using a modified example of the method of the present invention and a method not using it are compared. Ta.

Test N shows the method of FIG. 1 without using the variant.

Test 0 represents a variation of the method of the invention shown in FIG.

According to Tess) N, in the first stage of the process, in the suspension zone, the following Introducing 150 parts by weight of orchid-containing ore having a weight percent ffi composition of I entered.

U: 68.2% Mo: O, 13% zr: 2.44 copies Flat: 9.0% Others + H20: 20.23% Into the same zone (A) 123 parts by weight of water are introduced and then the amount of water required to form a homogeneous suspension is Stir for hours. Add an amount equivalent to 39 grams of 100% HNO3 to this suspension over 20 minutes. (Zone B). Next, to the suspension obtained as above (CyC), 29.01 1 (7) Add H2O2 (100%) (Lzt) for 20 minutes and add sodium hydroxide. (L22) was added to adjust the pH to 3.4. Hanging out of zone (C) In D) for suspension L3, maintain the suspension at a temperature of 30C for 2 hours under stirring. A ripening treatment was carried out.

The suspension L4 obtained in CD) is then separated in step (E) to form a liquid L5 and a solid phase S5. I got this. The solid phase 85 was treated with 200 parts by weight of water in the next K (F), and after washing A liquid L6 and a solid phase S6 were obtained.

Liquids L5 and L6 were mixed to obtain liquid L14. A portion L15 of the liquid L14 is in (A). It was then reused to suspend uranium-containing concentrate. The remaining part L16 is the first removed from the cycle to avoid impurities accumulating in the stage.

Liquid L14 contains 300 parts by weight of molyb originally present in the concentrate containing uranium. It contained 97.5% of Den. That is, the molybdenum is removed by liquid L14. It was.

Cake S6 after washing (F) was a wet cake of 260 parts by weight. At 60C After drying, the cake had the following weight percent composition:

U:68.0 Person in charge Mo: 0.02% Zr: 2.44% Na: 0.28chi Other 10 H20: 29.26% In the second stage of processing, the cake S6 obtained in the first stage of processing is It was treated with 60 parts of recycle liquid Ll11. Next, suspension L7 is 9 in (H) Treated with 3.6 parts of 100% HNO.

The acid was introduced slowly over a period of 20 minutes. The suspension L8 obtained was in CI) The temperature was brought to 90C and maintained at this temperature for 2 hours.

Suspension L9 coming out of zone (I) is separated in (J) to form liquid LIO and cake S1. Cake 81G obtained with ゜ was washed with 17 parts by weight of water (L25) in (K). , cake 811 and liquid Lll were obtained. Mix liquid L1o and Lll to make liquid L17. Configured. Liquid L17 was 500 parts by weight. This liquid L17 has the following composition. was.

U: 26.180% Mo: 0.007% Zr: 0.050% HzO + NOx + Other Near 3.763% A part of the purified liquid L17 is CG ), the cake S6 obtained in the first stage is reused to suspend it, and the remaining Part L19 of υ constituted the uranium production liquid. The cake Sll after drying at 60C is It weighed 9.5 parts by weight. The cake is initially present in the uranium-containing concentrate. It contains essentially 94.7% of zirconium, and the uranium concentration is the lowest in the concentrate. The amount was a loss of 0.4 t of the originally existing uranium. This loss is continuous In the case of the method (CM), it was resuspended in a weakly acidic solution L2s. Liquid I4 is (N ) and then reused as liquid L13 in (A).

According to test O, which shows the deformation method, in the first stage the suspension zone (A) is tested. ) 500 parts by weight of the same commercially available uranium-containing concentrate as N was introduced. in the same zone (A) 500 parts by weight of water were introduced and stirred for the time necessary to obtain a homogeneous suspension. the suspension An amount equivalent to 423 parts of 100% HNO3 was added to the solution over 20 minutes (Zone B).

Next, suspension L2 was introduced into (BA) and complexed with 57.6 parts by weight of KF and 90C. I did the right thing.

In the obtained aqueous medium L41 (BB), the suspension was stirred at a temperature of 90C. A ripening treatment was carried out in which the temperature was maintained for 1 hour.

The aqueous medium coming out of zone (BB) is cooled to a temperature of 30C in (BC). Ta.

In the cooled aqueous medium (in zone C) 330.8 parts (100%) HzO x (L21) was added over 25 minutes.

In CA), potassium hydroxide solution is added to the suspension L3 coming out of zone (C). was introduced to slowly adjust the pH, and the pH value was brought to 3.5.

In D) for the suspension L44 coming out of zone (CA), the suspension was heated to a temperature of 3. A ripening treatment was carried out at 6C and maintained for 45 minutes under stirring.

The suspension L4 obtained in (D) is then subjected to axiomatic treatment in (E) to obtain a liquid S in the same phase as the liquid L5. I got s.

The same phase S5 is then washed with 200 parts by weight of water in (F), and the washed liquid L6 and solid phase S6 were obtained.

Liquid L5 and L6 were mixed to form liquid L14. Part Lts of liquid L14 is (A) The remaining Li6 is recycled to suspend the uranium-containing concentrate. removed from the cycle to avoid accumulation of material.

fiL14 is 4,700 parts, which is the molybdenum originally present in the uranium-containing concentrate. It contained 97.6% of the total amount. The molybdenum is removed by this liquid L14. Ta.

Cake S6 after washing CF) was a wet cake of 1900 parts by weight.

After drying at 60C, the cake had the following composition by weight:

U: 65.17 Section Mo: 0.003% Zr: 2.52% Other 10HzO: 32.307% In the second stage of processing, the cake S6 obtained after the first stage of processing is in (G) It was then treated with 578 parts of recycled liquid L18.

Suspension L7 was then treated with 172 parts of 100% HNO3 in (H) . The acid was introduced at 85C for 120 minutes. The concerns obtained as above Suspension L8 was maintained at 85 tll' in CI) for 2 hours.

The suspension L9 coming out of zone CI) is separated in (J) to form liquid LIO and cake SI. I got O. Cake Sho k (K) VC+Zljoo parts by weight of water (L 25) to obtain cake Sll and iLu. 1 Mixing Lxo and Lll A liquid L17 was prepared. Liquid L17 was mixed at 2,850 parts by weight. This liquid L17 is The following composition remained.

U:2L5% Mo: 0.001% Zr: 0.010% H20 + NO3 + other near 8.489% purified saliva L17 is partially CG ), the cake 86 obtained in the first stage is reused to suspend and the remaining Part L19 constituted the uranium production liquid. The cake sti after drying at 60C is It weighed 32.0 parts by weight. The cake is initially present in the uranium-containing concentrate. The concentration of uranium in the concentrate is This amount represented a loss of 0.4% of the uranium originally present. This loss is In the case of the subsequent method (M), it was resuspended in weakly acidic liquid L2II. Liquid Lu is After filtration with (N), it is reused as liquid L13 in (A).

As mentioned above, by comparing test N and 0, we can obtain by a modification of the method of the invention It is clear that the purity of the uranium-containing liquid L19 increases very significantly.

Example In the example, the applicant obtained variations of the process according to the invention in three different industrial processes. The method was applied to three types of commercially available uranium concentrates.

One of them, Test O, has already been described in Example 5.

In Test P, a commercially available uranium-containing concentrate in the form of impure uranium 72 oscim was processed. be done.

In test Q, a commercially available uranium-containing concentrate in the form of impure uranium-based sodium was processed. Ru.

According to test P showing the deformation method, in the first stage, the following N content and composition were obtained. 469 parts of commercially available uranium-containing concentrate were introduced into the suspension zone (A).

U near 0.6% MO: Q, 19% Zr: 0.32% PO4: 0.28% 804: 5.32% NH4+: 1.4% Na: 1.05% Mg: 0.3% Funi + Others: 20.54/.

(Margin below) 500 parts by weight of water was introduced into the same zone and stirred for the time necessary to obtain a homogeneous suspension. Stirred. An amount equivalent to 423 parts of HNO3 was added to the suspension over a period of 20 minutes ( Zone B). Next, suspension L2 was introduced into (BA) and added to 7.84 parts by weight of KF. Complexation treatment was carried out at 90°C.

In the obtained aqueous medium L41 (BB), the suspension was stirred at a temperature of 90°C. A ripening treatment was carried out in which the temperature was maintained for 1 hour.

Temperature up to 30℃ in aqueous medium L42k (BC) coming out of zone (BB) Cooled.

In the cooled aqueous medium L43 (in zone C) 321 parts (100 g) of H2O2 ( L21) was added over 25 minutes.

In CA), potassium hydroxide solution L2 is added to the suspension L3 coming out of zone (C). 2i was introduced and the pH was slowly adjusted to a pH value of 3.5.

In D) for suspension L44 coming out of zone (CA), the suspension is heated to A ripening treatment was carried out at 36° C. and maintained for 45 minutes under stirring.

The suspension L4 obtained in (D) is then separated in (E) to form a liquid L5 and a solid phase S. I got 5.

The solid phase S5 is then washed with 200 parts by weight of water in (F) to obtain a washed liquid L6. and solid phase S6 were obtained.

Liquids L5 and L6 were mixed to form liquid L+4. Part L15 of liquid L14 is converted to (A) The remaining portion L16 is reused to suspend the uranium-containing concentrate in the first removed from the cycle to avoid impurity build-up at the stage.

Liquid L14 was 4,700 parts by weight and contained molyb which was initially present in the silalane-containing concentrate. It contained 98.9% of Den. The molybdenum is removed by this liquid L14. It was done.

Cake S6 after washing (F) was a wet cake of about 1900 parts by weight. 60 The cake after drying at °C has the following weight % composition: MO: 0.003% Zr: 0.39% Other Shimizu: 33.307% In the second stage of processing, the cake S6 obtained after the first stage of processing is in (G) 578 parts of recycled liquid LID was used. Next, suspension L7 is in (H) and treated with 172 parts of 100 To HNO3. This acid has 12 It was introduced slowly in 0 minutes. Suspension L8 obtained as above was in (I) and maintained at 85°C for 2 hours.

The suspension L9 coming out of zone (I) is separated in (J) to form liquid L1° and cake Si. I got n. Cake 810 in (K) with 1100 parts by weight of water (L25) After washing, cake S11 and liquid Lll were obtained. Mix liquid LIO and Lll to make liquid L. 17 were constructed. Liquid L+7 was 2850 parts by weight. This liquid T-tt'r is as follows. It had the following composition.

U2 21.6% Mo: 0.001% Zr: 0.010% H20 + NO, ten others: A part of the liquid L17 purified by 78.389% is (G ), the cake S6 obtained in the first stage is reused to suspend it, and the remaining 1 g of portion L constituted the uranium production liquid.

Cake 811 after drying at 60°C weighed 5 parts by weight. The cake contains uranium. Contains substantially 96.9% of the zirconium originally present in the concentrate. The uranium concentration represents the loss of 0.4% of the uranium originally present in the concentrate. there were. In the case of a continuous method, this loss is re-added to the weakly acidic liquid L26 in (M). suspended. Liquid L26 is reused in (A) as liquid L+3 after t in (N). used.

According to Tess) QK, which also shows a modification of the present invention, in the first stage, the following weight percentage set is 255 parts by weight of a commercially available uranium-containing concentrate of the same type as (Tess) N was added to the suspension zone. (A) was introduced.

U: 64.9ch Zr: 1.1 chi Na: g, 0 chi 8i0z: 2.7chi 804: 2.8% F: 0.1 chi Water, soil and others: 22.2ch Introducing 255 parts by weight of water into the same zone (A) as needed to obtain a homogeneous suspension. Stir for a while. An amount equivalent to 423 parts of iQQ%HNo3 was added to the suspension over 15 minutes. (Zone B). Next, suspension L2 was introduced into (BA) and 14.3 parts by weight of KF was added. The complexation treatment was carried out at a Schiff temperature of 5°C.

In the obtained aqueous medium L41 (BB), the suspension was transferred to zone (BB). The aqueous medium L42 that came out was cooled to a temperature of 30° C. in (BC).

In the cooled aqueous medium L43 (in zone C) 160 parts (100%) H2O2 ( L21) was added over 25 minutes.

In CA), potassium hydroxide solution L2 is added to the suspension L3 coming out of zone (C). 2 was introduced to slowly adjust the pH, and the pH value was brought to 3.5.

In D) for the suspension L44 coming out of zone (CA), the suspension was heated to a temperature of 3. A ripening treatment was carried out at 6° C. and maintained for 45 minutes under stirring.

The suspension L4 obtained in (D) is then separated in (E) to form a liquid L5 and a solid phase S. I got s.

Solid phase 8sk Next, in (F), wash with 200 parts by weight of water to obtain liquid L6 after washing. and solid phase S6 were obtained.

Liquids L5 and L6 were mixed to form liquid L+4. Part L15 of liquid L14 is converted to (A) The remaining part L1g is reused to suspend the uranium-containing concentrate in the first removed from the cycle to avoid impurity build-up at the stage.

Liquid L! 4 was 2500 parts by weight.

Cake S6 after washing (F) was a wet cake of 658 parts by weight. at 60℃ After drying, the cake had the following weight percent composition:

U: 64.4 Others + H20: 34.51% In the second stage of processing, the cake S6 obtained after the first stage of processing is in (G) Then, 1050 parts of 1 g of recycled liquid was added.

Next, suspension L7 was added to (H) by 1/-, and 87 parts O100% HNO3K yo') It has been processed. The acid was introduced slowly over 120 minutes at 85°C.

Suspension L8 obtained as above was maintained at 85° C. in (I) for 2 hours.

The suspension coming out of zone (I) is separated at t (J) into liquid LIO and cake 81 0 (!: obtained. Cake 81G in (K) 500 parts by weight of water (L25) Cake 811 and liquid Lll were obtained. Mix liquid LIO and Ll+ to make liquid L1? Completely configured. Liquid L17 was 2540 parts by weight. This liquid L17 is as follows. It had a composition.

U: 24.9% Zr: 0.005% H20+N03+Others: A portion of 70.595% purified saliva L+7 is (G ), the cake S6 obtained in the first stage is reused to suspend it, and the remaining Part L19 comprised the entire uranium production solution. Cake 811 after drying at 60℃ is It weighed 9.3 parts by weight. The cake is initially present in the uranium-containing concentrate. It contains substantially 98.9% of zirconium, and the concentration of uranium in the concentrate is This amount represented a loss of 2% of the uranium originally present. This loss is continuous In the case of method (M), it was resuspended in weakly acidic liquid L26. Liquid L26 is (N ) is reused as liquid L13 in (A).

Test 0 as above. From the comparison with P, Q and Tess) N, it is clear that the modified method of the present invention is Purity of uranium-containing liquid LI9 obtained regardless of the type of starting uranium-containing concentrate It can be proven to improve the degree of

￥= Cup FIG, 1 profit stage 1st M7' effect　j　Kaya 2P'iF effect FIG.2

Claims (1)

[Claims] 1. Contains impurities, and E, which appears in the impurities, is also a type O zirconium element. and/or to refine uranium-containing concentrates containing the element hafnium. said purification with hydrogen peroxide in a hot acidic aqueous medium to cause the formation of uranium oxide. In the first step, uranium is precipitated quantitatively and A slag containing uranium is suspended in an aqueous medium for the purpose of leaching all or part of the pure substance. Then, the suspension fI was acidified using an acidic agent in a loose manner and the obtained The acidified aqueous medium obtained is treated with supernoisy hydrogen to produce mainly uranium and zirconium and/or or forming a precipitate containing almost the entire amount of hafnium, and converting the precipitate into a precipitate containing impurities. The liquid phase is separated, and then in the second step, the precipitate obtained in the first step is acidified. The uranium is treated with a chemical agent to change it into soluble uranyl ions and elute them, producing uranyl. Liquid phase containing ions? Compounds containing zirconium and/or zirconium A method for refining a uranium-containing concentrate, characterized in that it is separated from the same phase formed by the uranium concentrate. 2. The introduction time of the acidic agent in the first stage is 5 to 200 minutes, and ρ is preferably 1. The uranium-containing M-mass according to claim IK, which is characterized in that the duration is 0 to 120 minutes. cold manufacturing method. 3. The amount of acidic agent introduced in the first stage is such that the concentration of free H' after acidification is at least 0.01N preferably at least 0.01N. of a claim characterized in that the amount is IN. A method for refining uranium-containing concentrate according to scopes 1 and 2. 4. Claims characterized in that the acidified aqueous medium is a suspension or a solution. 4. A method for refining a uranium-containing concentrate according to any one of 1 to 3. 5. The treatment of the acidified aqueous medium with A-dispersed hydrogen is preferably 80°C or lower. A claim that @mold is carried out at a temperature adjusted in the range of 0°C to 40°C. The method for purifying uranium-containing M-like substances according to any one of 1 to 4 above. 6. Amount of uranium peroxide introduced into the polymerized aqueous medium 71) Precipitation of uranium peroxide 2 to 10 times the stoichiometric amount at least equal to the stoichiometric amount required for The uranium-containing concentrate according to any one of claims 1 to 5), characterized in that Purification method 7, in which the acidified aqueous medium is treated with a fluoride source. Refining of uranium-containing concentrate according to any one of claims 1 to 4, characterized in that Method. 8. The temperature of the acidified medium is at least equal to 70°C, preferably 90°C to 1 The uranium-containing mineral according to claim 7, characterized in that Method of refining ore. 9. Compound HF, N in which a fluoride ion source is used alone or as a mixture It is specially composed of aF, KF, NH4F, Na2S iF6. 8. The method for refining a uranium-containing concentrate according to claim 7. 10 The molar ratio F/(Zr + Hf) is at least equal to 1, especially in the range of 4 to IQ The uranium-containing concentrate according to any one of claims 7 to 9, characterized in that Purification method. 11. The temperature of the aqueous medium of the complexing agent introducer is preferably at least 70°C, ¥'X, 90 Any of claims 7 to 10, characterized in that the temperature is maintained between 100°C and 100°C. A method for refining the uranium-containing concentrate described in f'L. 12. The combined aqueous medium containing the name-forming agent is heated for up to 6 hours, preferably from 1 to Any one of claims 7 to 11, characterized in that the method is maintained under stirring for 4 hours. Method for refining the described uranium-containing concentrate. 13. The acidified aqueous medium containing the complexing agent is heated to at least 70°C, preferably Ir. Claim 12, characterized in that the temperature is maintained at 190°C to 100°C. Method for refining uranium-containing concentrate. 14. The complexed acidic medium is cooled to a temperature of 60°C, preferably 30°C to 40L. The uranium-containing material according to any one of claims 7 to 13, characterized in that the uranium-containing material is Method of refining concentrate. 15. The suspension after peroxidation is reduced by the introduction of an alkaline agent from a range of 2.5 to 45. Claims 7 to 14 characterized in that selected pHK warming and spirit toning are performed. A method for refining a uranium-containing concentrate as described in the above. 16. The suspension obtained after treatment with hydrogen peroxide is maintained for up to 6 hours, preferably from 2 to Any one of claims 1 to 15, characterized in that it is maintained under stirring for 4 hours. The method for refining the uranium-containing iH ore. 17. The temperature of the suspension obtained after treatment with hydrogen peroxide is 80°C or lower, preferably 30°C. Any of claims 1 to 16, characterized in that the temperature is maintained at a temperature of 40°C to 40°C. D. A method for refining nolan-containing axillary ore. 18. The precipitate obtained after the first stage is treated with an acidic agent in its original state. The uranium-containing concentrate according to any one of claims 1 to 17, characterized in that Manufacturing method. 19. The precipitate obtained from the first step is suspended in acidified water or a recycle liquid. The utensil according to any one of claims 1 to 18 'D), characterized in that A method for refining orchid-containing ore. 20 The detergent needed to treat the precipitate obtained in the first stage corresponds to the presence of uranium. Any one of claims 1 to 19 characterized in that the stoichiometric value is 1 or less. The method for refining the five uranium-containing ores described in . 21. Treatment of the precipitate obtained in the first step with an acidic agent at 60°C to 100°C Claim 1 characterized in that the process is carried out at a temperature of 785°C to 95°C. 20. The method for refining a uranium-containing concentrate according to any one of 20 to 20. 22. Treatment of the precipitate obtained from the first step with an acidic agent is preferably carried out for at least 1 hour. or 3 to 5 hours. A method for refining a uranium-containing concentrate according to item (n). 23. The precipitate obtained in the first step is treated with an acidic agent to obtain a turbid liquid. Any one of claims 1 to 22, characterized in that it is cooled to a temperature of 0°C or less. A method for refining uranium-containing ore described in the furnace. 24 The acidic agents used in the first and second stages are nitric acid, nitric acid, hydrochloric acid and and a mixture of two or more of the aforementioned acids. A method for purifying uranium-containing pyrotechnic materials as described in Items 1 to 23 above.