Method for ion-exchange recovery of uranium from sulfuric acid solutions and pulps

FIELD: uranium technologies.

SUBSTANCE: method comprises sorption of uranium on low-basicity anionites, desorption of uranium, and recovery of finished product. In particular, uranium-saturated low-basicity anionite is converted into OH- form and uranium into soluble stable complex [UO2(CO3)3]-4 by treating sorbents with alkali metal and ammonium carbonate solutions.

EFFECT: achieved complete desorption of uranium and simultaneously sorbent is freed from poisons and other sorption components.

2 dwg

 

The invention relates to the field of ion-exchange technology to extract uranium from solutions and slurries obtained in the sulfuric acid leaching of uranium ores.

Known ion-exchange process for the recovery of uranium from solutions and slurries obtained in the sulfuric acid leaching of uranium ores. The method includes the processes of sorption of uranium on strong-base anion exchange resin, the desorption of uranium on strong-base anion exchange resins solutions:

- sulfuric acid (˜ 150 g/l)

- nitric acid mixture with sulfuric acid

- sodium nitrate, acidified with sulfuric acid

and processing of commodity decorativ or method of extraction or precipitation.

/Boris Gromov. Introduction to uranium. Moscow: Atomizdat. 1978, p.140-150/.

The known method has a number of disadvantages associated with the difficulties of the implementation processes of desorption of uranium and the subsequent processing operations commodity decorate.

When desorption of sulfuric acid obtained trademark decorate uranium, the volume of which is large - more than 5 volumes with 1 resin (respectively the concentration of uranium in them small). The content of sulfuric acid in the product decorate little different from the concentration of sulfuric acid in the original desorbers solution, therefore, the deposition of diuranate sodium (or ammonium) from these solutions it is impossible for those who technological reasons. For the extraction of uranium from such solutions is used extraction, which in the conditions of underground and heap leaching unprofitable.

When used in the desorption process solutions containing nitrates or chlorides, these ions are in the process of sorption of uranium, where largely depressioon sorption of uranium, reducing the completeness of extraction of the ion exchanger.

Closest to the proposed method is a method of uranium extraction in weakly basic anion exchangers. [Hardner, Rconn. The use of weakly basic anion exchange resin to extract uranium from deposits Uravan, Colorado, USA. In the book "Theory and practice of ion exchange". Proceedings of the International conference. Cambridge, London. 1976]

For the experiments we used the weakly basic anion Amberlit HEH-270 and Amberlite HEH-299. Experiments have shown that the processes of sorption of uranium on these anion exchange resins are intensively, not much different from the sorption characteristics on strong-base anion exchange resin. For desorption of uranium used traditional desorbers solutions:

- sulfuric acid;

- a mixture of sulfuric acid and sulfates of alkali metals and ammonium;

- a mixture of sulphuric acid and chlorides of alkali metals and ammonium;

- solutions of chlorides of alkali metals and ammonium.

All of these processes desorption on the weakly basic anion exchange resin about the ecay similar processes in strongly basic anion exchange resin. It was stated that after the accumulation of the resin poisons (silicates, polythionates and other) necessary treatment of the resin with sodium hydroxide.

Thus, the process of uranium extraction in weakly basic anion exchangers retain all the disadvantages of the processes of extraction of uranium on strong-base anion exchange resin. In this regard, industrial use for the sorption of uranium weakly basic anion exchange resin is not found.

The technical result of the invention is the complete desorption of uranium on the weakly basic anion exchange resin with simultaneous cleaning of sorbents from "poisons" and other components of sorption.

The technical result is achieved by the method of ion-exchange extraction of uranium from sulfuric acid solutions and slurries, including sorption of uranium on the weakly basic anion exchangers desorption of uranium, production of finished goods from decorate, desorption from saturated uranium weakly basic anion exchange resin is carried out by treatment of the sorbent solution of carbonate of alkali metal or ammonium carbonate with the transfer of the anion in the HE-form, and uranium in a soluble, stable complex [UO2(CO3)3]-4.

When the transfer of the anion in the HE-form of the anion exchange resin is removed together with all uranium sorbed components, including those components that are in an acidic environment are "poisons" for the ion exchanger. While the system sorption-desorption do not enter other components which are the depressors in the process of sorption of uranium, such as the nitrate or chloride ions.

The content of carbonate used for desorption in the product solution is minimal.

Weakly basic anion exchange resin in the HE-form medicationbuy and no other anions do not absorb and, therefore, the ion in alkaline medium are not. During the alkali treatment they completely transformed into HE-form, giving deformirujuschij solution all sorbed ions, including all the "poisons"caught in the resin in the process of sorption. The use of hydroxides for desorption of uranium impossible due to the formation of insoluble uranylacetate, which are deposited in phase resin. Therefore, desorption of uranium should be used water-soluble carbonates of alkali metals and ammonium. In this case, the uranium is bound in a stable uranyl tricarbonate complex, soluble in water.

The reaction desorption of uranium proceeds in accordance with the equation:

R+UO2(SO4)3+IU2CO3→R-OH+IU4[UO2(CO3)3]+Me2SO4

From the resulting solution (trademark dealbata)containing the minimum number of original carbonate of an alkali metal, it is easy to distinguish sediment diuranate alkali metal or ammonium traditional methods that very in the tenderly when using the proposed method especially in areas heap or the ISL.

When returning the anion exchange resin in the process of sorption reaction takes place neutralization of HE-form

R-OH+H2SO4→R-SO4+H2O

then the anion exchanger acquires the ability to ion exchange reactions.

Example:

Study of the sorption of uranium was performed using real production solutions heap leaching. For used weakly basic anion exchange resin:

- Lewatit

- Purolite A500

S-3

S-7

- Purolite A100

- EAP-1P.

and strong-base anion exchange resin AMP that has the best performance on the sorption of uranium to compare.

Figure 1 shows the dependence of the capacitance of the sample resins for uranium concentration of uranium in the equilibrium solution. Isotherms sorption from solutions heap leaching:

T=6 hWithH2SO4=7,8 g/l
pH=1,3SO4=34 g/l
t=32°CFe3+=2,04 g/l

U=Var

1 - Lewatit

2 - Purolite A500

3 S-3

4 - Purolite And 100

5 - VP-1P

6 - AMP

The figure shows that the capacity of the weakly basic anion exchange resin is slightly different from the capacity strong base anion exchanger AMP and can be used to extract uranium from sulfuric acid environments.

When carrying out the sorption of uranium in the dynamic mode of solutions heap leaching with sod is a neigh uranium to about 200 mg/l were obtained capacity for strong-base anion exchanger AMP - 33 g/l, and for weakly basic anion exchange EAP-1P and Purolite A 100 - about 30 g/L.

Currently synthesized in industrial-scale production of new models of weakly basic anion exchange resin ARS and AMS, with a capacity of uranium by 5-10% above the capacity of the SFA.

Desorption of uranium on the weakly basic anion exchange resin was carried out with solutions of caustic soda concentration of 100 g/l

For preliminary experiments were used weakly basic anion exchange resin S-3 and S-7. The capacity of the uranium standard solutions was 40 g/l and 45 g/l, respectively.

After treatment with a solution of soda in the static mode, the remaining capacity of the ion exchangers, respectively 0,034 g/l and 0.008 g/l, respectively. This indicator is to ensure complete extraction of uranium from sulfuric acid environments.

The residual capacity of the ion exchanger AMP after treatment with sulfuric acid (stronger desorbent than soda solution) is not less than 2 g/L.

Figure 2 shows the results of desorption of weakly basic anion exchange resin with a solution of baking soda in a column in the dynamic mode.

On fega:

1. Purolite A-100

Desorption solution 5% Na2CO3

2. AM - 7D

Desorption solution 5% Na2CO3

3. Purolite A-100

Desorption solution 20% Na2CO3

ERef=43,6 g/l

EDesorb= 0,1

The output of commodity decorate having a pH of 7.2, amounted to 1 volume of the volume of the resin. Soda almost on the scale the amount spent on moving the resin in the HE -form.

Thus, the volume of commodity decorate is determined only by the total exchange capacity of the resin and the concentration of the Stripping solution of soda.

FIVB confirms the correctness of the above mechanism of the desorption process uranium at a weakly basic anion exchangers. ERef=34,9. For desorption of used soda solution (20%) with the original content of uranium is equal to 49 g/L. Despite the very high uranium content, the residual capacity of the resin for uranium was 0,255 g/l, i.e. the formation of medicationabana HE--form occurs regardless of what other anions are in the system.

The concentration of uranium in the product decorate is calculated by material balance and is about 20 g/L.

Desorption of uranium using potassium carbonate showed similar results.

Experiments on desorption of uranium on the resin AM-7 solutions (˜ 100 g/l) of ammonium carbonate was shown that the process is intensive, and remaining after desorption capacity for uranium amounted to about 0.3 g/L.

The process of extracting uranium from sulfuric acid environments on a weakly basic anion exchange resin flows only from phase solution. The presence in the original sulfate uranium solution with an inert solid particles does not affect the flow of the ion-exchange reaction, and defines only the instrumentation process.

Thus, note the imposition of the weakly basic anion exchange resin to extract uranium from sulfuric acid media in the processing of uranium ores allows you to:

- to increase the degree of extraction of uranium from ore due to the low residual uranium content in the resin supplied into the process of sorption;

to reduce the costs for the desorption process;

- to obtain a concentrated uranium commodity decorate in an amount equal to the value

where Etotal- total exchange capacity of the resin;

WithR-RAthe concentration of the carbonate of an alkali metal or ammonium in desorbers solution;

- eliminate the negative effects of poisons that accumulate on the resin in the process of sorption of uranium (silicates and other)as a weakly basic resin in the HE-form are not sorbents;

- eliminate ingress into the system for processing ores undesirable in sorption and environmental aspect components, such as nitrate or chloride ions.

Developed based on the sorption of uranium on the weakly basic anion exchangers for one of the plots heap leaching method is simple technology and equipment design.

The method of ion-exchange extraction of uranium from sulfuric acid solutions and slurries comprising the sorption of uranium on the weakly basic anion exchangers desorption of uranium, production of finished goods from decorate, characterized in that the desorption from saturated uranium weakly basic anion exchange resin is carried out by treatment of the sorbent dissolve the om carbonate of an alkali metal or ammonium carbonate with the transfer of the anion in the HE -form, and uranium in a soluble stable complex [UO2(CO3)3]-4.



 

Same patents:

FIELD: chemical technology; deactivation and decontamination of radioactive industrial products and/or wastes.

SUBSTANCE: proposed method designed for deactivation and decontamination of radioactive industrial products and/or production wastes incorporating Th-232 and its daughter decay products (Ra-228, Ra-224), as well as rare-earth elements, Fe, Cr, Mn, Al, Ti, Zr, Nb, Ta, Ca, Mg, Na, K, and the like and that ensures high degree of coprecipitation of natural radionuclides of filtrates, confining of radioactive metals, and their conversion to environmentally safe form (non-dusting water-insoluble solid state) includes dissolution of wastes, their treatment with barium chloride, sulfuric acid, and lime milk, and separation of sediment from solution. Lime milk treatment is conducted to pH = 9-10 in the amount of 120-150% of that stoichiometrically required for precipitation of total content of metal oxyhydrate; then pulp is filtered and barium chloride is injected in filtrate in the amount of 0.4 - 1.8 kg of BaCl2 per 1 kg of CaCl2 contained in source solution or in pulp and pre-dissolved in sulfuric acid of chlorine compressors spent 5-20 times in the amount of 0.5 - 2.5 kg of H2SO4 per 1 kg of BaCl2. Then lime milk is added up to pH = 11 - 12 and acid chloride wash effluents of equipment and production floors are alternately introduced in sulfate pulp formed in the process at pulp-to-effluents ratio of 1 : (2-3) to pH = 6.5 - 8.5. Filtrate pulp produced in this way is filtered, decontaminated solution is discharged to sewerage system, sediment of barium and calcium sulfates and iron oxysulfate are mixed up with oxyhydrate sediment formed in source pulp neutralization, inert filler and 0.5 - 2 parts by weight of calcium sulfate are introduced in pasty mixture while continuously stirring them. Compound obtained in the process is placed in molds, held therein at temperature of 20 - 50 oC for 12 - 36 h, and compacted in blocks whose surfaces are treated with water-repelling material.

EFFECT: reduced radioactivity of filtrates upon separation of radioactive cakes.

8 cl, 1 dwg, 1 ex

FIELD: chemical technology; recovery of deactivated and decontaminated radioactive industrial wastes.

SUBSTANCE: proposed method that can be used for deactivating and decontaminating industrial radioactive wastes incorporating Tb-232 and their daughter decay products (Ra-228, Ra-224), as well as rare-earth elements, Fe, Cr, Mn, Sl, Ti, Zr, Nb, Ta, Ca, Mg, Na, K, and the like includes dissolution of wastes, treatment of solutions or pulps with barium chloride, sulfuric acid, and lime milk, and separation of sediment from solution. Lime milk treatment is conducted to pH = 9 - 10 in the amount of 120-150% of total content of metal oxyhydrates stoichiometrically required for precipitation, pulp is filtered, and barium chloride in the amount of 0.4 - 1.8 kg of BaCl2 per 1 kg of CaCl2 contained in source solution or in pulp, as well as pre-diluted sulfuric acid spent 5 - 20 times in chlorine compressors in the amount of 0.5 - 2.5 kg of H2SO4 per 1 kg of BaCl2 are introduced in filtrate. Alternately introduced in sulfate pulp formed in the process are lime milk to pH = 11 - 12, then acid chloride wash effluents from equipment and industrial flats at pulp-to-effluents ratio of 1 : (2 - 3) to pH = 6.5 - 8.5, and pulp obtained is filtered. Decontaminated solution is discharged to sewerage system and sediment of barium and calcium sulfates and iron oxysulfate are mixed up with oxyhydrate sediment formed in source pulp neutralization process; then 35 - 45 mass percent of inert filler, 10 - 20 mass percent of magnesium oxide, and 15 -m 25 mass percent of magnesium chloride are introduced in pasty mixture formed in the process while continuously stirring ingredients. Compound obtained is subjected to heat treatment at temperature of 80 - 120 oC and compressed by applying pressure of 60 to 80 at.

EFFECT: reduced radioactivity of filtrates upon separation of radioactive cakes due to enhanced coprecipitation of natural radionuclides.

7 c, 1 ex

FIELD: rare, dispersed and radioactive metal metallurgy, in particular hydrometallurgy.

SUBSTANCE: invention relates to method for reprocessing of polymetal, multicomponent, thorium-containing radwastes, formed when reprocessing of various mineral, containing rare-earth elements, Nb, Ta, To, V, Zr, Hf, W, U, etc. Method includes treatment of solution and/or slurry with alkaline agent; introducing of sulfate-containing inorganic compound solution and barium chloride; treatment of obtained hydrate-sulfate slurry with iron chloride-containing solution, and separation of radioactive precipitate from solution by filtration. As alkali agent magnesia milk containing 50-200 g/dm2 of MgO is used; treatment is carried out up to pH 8-10; sodium sulfate in amount of 6-9 g Na2SO4/dm2 is introduced as solution of sulfate-containing inorganic compound; barium chloride solution is introduced in slurry in amount of 1.5-3 g BaCl2/dm2. Hydrate-sulfate slurry is treated with solution and/or slurry containing 0.8-16 Fe3+/dm2 (as referred to startingsolution) of iron chloride, followed by treatment with high molecular flocculating agent and holding without agitation for 0.5-2 h. Radioactive precipitate is separated from mother liquor, washed with water in volume ratio of 0.5-2:1; then washed with sodium chloride-containing solution and/or slurry in volume ratio of 0.5-2:1; radioactive precipitate is removed from filter and mixed with mineral oxides in amount of 0.5-0.8 kg MgO to 1 kg of precipitate. Formed pasty composition is fed in forms and/or lingots and presses with simultaneous heating up to 80-1200C.

EFFECT: filtrate with reduced radioactivity due to increased codeposition coefficient of natural Th-232-group radioactive nuclide, in particular Ra-224 and Ra-228, with radioactive precipitates.

10 cl, 1 ex

The invention relates to the processing of uranium ores

The invention relates to a technology developing concentrates of rare earth elements from natural phosphate concentrates

The invention relates to the processing orangutango raw materials

The invention relates to methods of non-aqueous dissolution of uranium and uranium-containing materials and can be used to extract uranium from spent nuclear fuel, metallurgical wastes of uranium and its alloys and products

The invention relates to the nuclear industry and can find application in the manufacturing of fuel for nuclear power reactors

The invention relates to hydrometallurgy uranium and can be used to produce uranium hexafluoride from solutions of different composition using the processes of extraction, Stripping and heat treatment

The invention relates to a hydrometallurgical methods of ore processing and can be used to extract uranium from ore materials by means of heap (KV) and underground (PV) leaching

FIELD: precious metal hydrometallurgy.

SUBSTANCE: rhenium-loaded sorbent is treated with 4-5 M hydrochloric acid in contact with another sorbent, in particular solid extractant containing asymmetric phosphine oxide, after which sorbent is separated from mixture and treated with ammonia or ammonium carbonate solution.

EFFECT: combined rhenium desorption and eluate purification operations.

7 ex

FIELD: precious metal hydrometallurgy.

SUBSTANCE: invention relates to methods for sorption-assisted recovery of metals from materials containing them. Method of invention proposes recovering precious metals from solution in redox mixture with involvement of sorption of these metals by added sorbent, which is further burnt down. Sorbent is added portionwise and weight of each portion constitutes 0.11-0.50 total weight of added sorbent. Portions are added in time moments between the beginnings of two consecutive additions within a time range constituting 0.14-0.86 total sorption time period. Moreover, number of sorbent portions is selected between 2 and 9.

EFFECT: increased degree of precious metal recovery.

4 cl, 16 ex

FIELD: hydrometallurgy.

SUBSTANCE: invention relates to recovering metal ions from aqueous solutions with the aid of clay minerals and can find use in nonferrous and ferrous metallurgies as well as in waste water treatment. Essence of invention resides in adding clay materials to solution in question followed by stirring and settling. Recovery of cations is effected at pH 2.6 to 10 over a period of time not exceeding 120 min and recovery of anions at pH 1 to 4 during at most 30 min. Clay minerals utilized are sea-origin hydromicas Irilit-1 and Irilit-7.

EFFECT: enhanced of metal ions recovery efficiency, reduced expenses due to use of non-costly sorbents, and reduced consumption of reagents.

2 cl, 3 tbl, 5 ex

FIELD: extraction of agent by means of sorbents; ferrous and non-ferrous metallurgy; cleaning domestic and industrial drainage passages; processing wastes of non-ferrous metals containing (VI) tungsten.

SUBSTANCE: proposed method includes sorption of (VI) tungsten on macroporous anionite at correction of ph ≤ 5. Prior to sorption, anionite is treated with water, acid solution or alkali solution.

EFFECT: enhanced efficiency.

6 dwg, 6 tbl, 6 ex

FIELD: hydraulic metallurgy of thallium, possibly extraction and removing ions of non-ferrous metals from isotope-enriched thallium.

SUBSTANCE: method comprises steps of sorption of thallium from nitrate solutions; before sorption treating initial nitrate solutions with organic reducing agent such as alcohol or formaldehyde solution until pH 1.5 - 2.5; adding complexone II or III in quantity 1.2 - 1.5 mol of complexone per 1 mol of total quantity of impurities; correcting solution until pH 4 - 5 by means of ammonium; realizing desorption of thallium by means of ammonium sulfate solution (2 - 4 M) after preliminary removal of impurities from cationite by washing it with water and with solution of complexone II or III; or performing after-purification (after desorption) of eluates with use of anionite of epoxy-polyamine type.

EFFECT: lowered number of operations, reduced consumption of reagents, prevention of outbursts of harmful matters to atmosphere, improved effectiveness.

3 cl, 11 tbl, 11 ex

FIELD: noble metal metallurgy, in particular gold recovery from churlish hard-cleaning raw materials such as coal and divot.

SUBSTANCE: cold-containing raw materials (e.g., black and brown coal and divot) contains gold in form of chemical compound with complex organic substances such as guminic acid, and in process of fuel burning gold easily volatilizes together with gaseous burning products. Method of present invention includes backing of said raw materials under air discharge and sublimate is absorbed by passing of exhaust gases through vessel with water and column filled with granulated activated carbon as sorptive agent.

EFFECT: gold recovery from gold-containing raw material with improved yield.

1 ex, 1 tbl

FIELD: waste water treatment and hydrometallurgy.

SUBSTANCE: invention relates to recovering palladium from nitric acid, nitric acid-hydrochloric acid, and nitric acid-fluoride-hydrochloric acid solutions used for etching parts and units of equipment for isotope separation chambers. Palladium is sorbed from solutions having nitric acid concentration 30 to 250 g/L with mixture of epoxypolyamine-type low-basicity anionite, containing alternating groups of secondary and tertiary amines, ethers, and alcohols, and high-basicity anionite with quaternary ammonium base groups, content of low-basicity anionite (e.g. AN-31) being 98-99% and that of high-basicity anionite (e.g. AV17*8) 1-2%. Thereafter, anionites are subjected to stepped combustion: first for 2-4 h at 350-400°C and then for 2-4 h at 950-1000°C to produce metallic palladium, which is cooled under vacuum or in an inert gas atmosphere.

EFFECT: increased selectivity of refining process removing polyvalent metal impurities and increased degree of recovery.

6 tbl, 5 ex

FIELD: hydrometallurgy.

SUBSTANCE: invention relates to sorption-mediated recovery of molybdenum from solutions containing heavy metal cations. Method of invention comprises providing solution to be treated, sorption of molybdenum(VI) on anionite at pH < 7. Sorption is conducted from solutions with anionites AM-2b and AMP at solution pH below pH of hydrolytic precipitation of heavy metal cations but higher than pH of formation of molybdenum cations (pH ~ 1).

EFFECT: increased process selectivity and reduced number of stages in preparation of pure molybdenum.

9 dwg, 3 tbl, 4 ex

The invention relates to the processing of uranium ores
The invention relates to hydrometallurgy, in particular to the processing of molybdenum concentrates and waste

FIELD: hydrometallurgy.

SUBSTANCE: invention relates to sorption-mediated recovery of molybdenum from solutions containing heavy metal cations. Method of invention comprises providing solution to be treated, sorption of molybdenum(VI) on anionite at pH < 7. Sorption is conducted from solutions with anionites AM-2b and AMP at solution pH below pH of hydrolytic precipitation of heavy metal cations but higher than pH of formation of molybdenum cations (pH ~ 1).

EFFECT: increased process selectivity and reduced number of stages in preparation of pure molybdenum.

9 dwg, 3 tbl, 4 ex

Up!