Processing method of nitric-acid solution of regenerated uranium with removal of technetium (versions)

FIELD: metallurgy.

SUBSTANCE: processing method of nitric-acid solution of regenerated uranium involves uranium (VI) extraction with tributyl phosphate in organic diluter; flushing of extract with nitric-acid solution and re-extraction of uranium. At that, removal of technetium from uranium is performed by shifting technetium (VII) to non-extracted quadrivalent state in flushing zone of extraction cascade with the use of flushing solution containing 0.1-0.2 mol/l of carbohydrazide and 0.05-0.15 mol/l of nitric acid. Extract is flushed at the ratio of flows of organic and water phases, which is equal to 10-15. Method can be implemented in two versions. As per the first version, used flushing solution is supplied to feed stage of extraction cascade and technetium is removed to raffinate. As per the second version, used flushing solution is a separate flow from which uranium is extracted by contact with flow of fresh extractant; organic phase is connected to initial uranium extract prior to supply to flushing zone, and technetium is removed to separate product the volume of which is 5 times less than the raffinate volume.

EFFECT: increasing separation efficiency of uranium and technetium.

9 cl, 2 dwg

 

The invention relates to methods of extraction processing of regenerated uranium to clean from technetium-99, which is the beta-active emitter, in which the extractant is used tributyl phosphate (TBP) in an organic diluent.

The extraction of uranium from nitric acid solutions of technetium, located in the heptavalent state sextrailers tributylphosphate, together with uranium in the form of an anionic complex:

UO2(NO3)2(TBP)2+TCO4-=UO2(NO3)TCO4)(TBP)2+NO3-

In all known processes of extraction and purification of uranium from technetium utilize the principle of the transfer of technetium from the heptavalent state in which he sextrailers with uranium in tetravalent poorly extractable state. The efficiency of purification of uranium from technetium is determined by the degree of recovery of technetium (VII) to TC (IV).

Various methods of recovery of technetium (VII). In the processing of uranium as reductants of technetium (VII) in nitric acid solutions of uranyl nitrate can be used hydrazine and tetravalent uranium.

A known method of purification of uranium from technetium, in which technetium (VII) in the original nitric acid solution of uranyl nitrate before extraction of 30%TBP in an inert rasnavitsnavia hydrazine (U.S. patent 4443413, IPC 01G 43/00; C01G 57/00, publ. 17.04.1984). While technetium, located in the restored form, appears in the raffinate. The disadvantage of this method is the low degree of extraction of uranium in the process of its extraction because of the need to maintain a low concentration of nitric acid in aqueous solution (0.01-0.1 mol/l) for stabilization of technetium in reduced state.

The known method of extraction purification of uranium (VI) from technetium, in which technetium (VII) in nitric acid solution UO2(NO3)2before extraction of uranium of 30%TBP in the organic diluent restore hydrazine and restored technetium zakompleksovany oxalic acid, i.e. transform technetium in dextrogyrate form (U.S. patent 4528165, IPC 01G 43/00; C01G 57/00, publ. 09.07.1985). The disadvantage of this method is to reduce the degree of extraction of uranium (VI) in the process of extraction and intake of oxalate ion in the raffinate.

A known method of purification of uranium from technetium (patent RU №2184083, IPC C01G 43/00, C01G 57/00, publ. 27.06.2002), including the restoration of an aqueous solution of uranyl nitrate technetium (VII) with hydrazine, the extraction of uranium (VI) with tributyl phosphate in an organic diluent, washing of the extract uranium (VI), characterized in that the recovery of technetium (VII) is carried out in a solution of uranium (VI) at a molar ratio of [NO3-]/[U(VI)] in combination is wound less than two, that is, in conditions of deficiency of nitric acid.

Recovery of technetium (VII) is carried out in the presence of uranium (IV). The disadvantage of this method is that with the introduction of the original solution of uranium (VI) with a deficit of nitric acid solution of uranium (IV) in local areas with a large concentration of uranium (IV), we observed the formation of hydrolyzed uranium (IV). When incomplete mixing of solutions of precipitation can be stored (this can be seen in the production environment when preparing large volumes of solutions)that leads to the violation of technological process until the reverse oxidation of technetium (IV) to heptavalent state and termination cleanup of uranium (VI) from technetium in the extraction surgery. In addition, the uranium (IV) in solutions with deficiency of nitric acid acidified quickly enough, there is a significant decrease in the concentration of uranium (IV) until its complete oxidation. Therefore, the solution is injected obviously more uranium (IV). This leads to increased discharges of uranium (IV) with the raffinate in the initial filing period feed solution on the extraction and the impossibility of achieving waste uranium concentrations in the raffinate.

A known method of purification of uranium from technetium (patent RU №2354728, IPC SW 60/02, C01G 43/00, G21C 19/46, B01D 11/04, publ. 10.05.2009), including the recovery of technetium (VII) in an aqueous solution of uranyl Nitra is and nitrate with a solution of hydrazine in the presence of uranium (IV), characterized in that the recovery of technetium are no more than 20 minutes when the value of the excess of nitrate-ion with respect to its quantity in the uranyl nitrate 0,15-of 0.94 mol/l In the dependent claims indicate that the recovery of technetium (VII) is carried out at the simultaneous submission of a solution of nitrate of uranium (VI)containing technetium (VII), and solution of uranium (IV) in the extraction apparatus.

The disadvantage of this method is that the supply of uranium (IV) in the supply step at a stated interval of concentration of nitric acid and the flow ratio of organic and aqueous phases, is equal to 2 or more, will retrieve it in the organic phase and further transport in the zone of leaching extract, thereby eliminating further interaction of uranium (IV) with technetium (VII) in the area of extraction. The movement of the aqueous phase from step power lead level at low concentrations of hydrazine and taking into account the oxidation of technetium (IV) technetium (VII) will lead to the extraction of the oxidized form of technetium in the organic phase and the uptake of technetium in the supply step, i.e. it is possible the integrated activities will include technetium along the lines of the organic phase. This will require additional supply of reducing agent or stream power, which is ineffective, or in the stage area of the extraction of uranium. When implementing this method should be aware that one of the products of the catalytic (p is outstay technetium) oxidation of hydrazine is attestation acid, which migrates as water and organic streams. When the limited duration of the recovery operation of technetium minimizing the consumption of reducing agents to the equipment are increased requirements in terms of metering equipment, because of the required coordination costs of a solution of uranyl nitrate containing technetium, and the solution of reducing agent.

A known method of purification of the recycled uranium removal of technetium (patent RU 2373155 C2 (IPC C01G 43/00, publ. 20.11.2009), including extraction of uranium (VI) with tributyl phosphate in an organic solvent, purification of the uranium nitrate solution containing the reducing agent, and reextraction uranium. In use as a reducing agent uranium (IV), stable hydrazine.

The technical essence and achieved the positive effect of this method is the closest to the claimed method and selected as a prototype.

The disadvantage of the prototype is that the purification of uranium from technetium in countercurrent cascade is carried out in two steps using three reagents:

- hydrazine (restorer of technetium (VII) to TC (IV)and sodium hexametaphosphate (combined technetium (IV)) are served by separate threads in the original nitric acid solution of uranium (VI); at the same time to avoid sludge formation FOSFA the s uranium (IV) and technetium concentration of sodium hexametaphosphate is supported at the level of not more than 0.02 mol/l;

- vytesnitelya recovery solution containing uranium (VI) up to 110-115 g/l), uranium (IV) and the stabilizer - hydrazine serves on the operation of the washing of the extract uranium from technetium.

The use of uranium (IV) and hydrazine at low concentrations (no more than 2 g/l) in the next stage of the cascade when the volume ratio between organic and aqueous phases, is equal to 2 and more ineffective, because the concentration of uranium (IV), extracted in the organic phase, is significantly reduced and will not ensure effective recovery of technetium in the organic phase. There are conditions reverse oxidation of technetium in the higher valence state. The increase in the concentration of reducing agents will lead to the accumulation of attestations acid in technological solutions.

The use of uranyl nitrate in the composition of the leaching solution inevitably leads to its recycling scheme and reduce the direct output of uranium in the final product.

The presence of phosphate ion in the raffinate after extraction will require special treatment with this solution and excludes the operation of the evaporation of the raffinate with the purpose of recovery of nitric acid.

The objective of the invention is to increase the efficiency of separation of uranium and technetium, elimination of conditions reverse oxidation of technetium (IV) to heptavalent state and education attestation acid, the reduction is their volume of liquid radioactive waste, reduced operating costs associated with obtaining uranium (IV).

In the first variant of the proposed method the problem is solved in that in the method of extraction processing of regenerated uranium, including extraction of uranium from nitric acid solution of uranyl nitrate) with tributyl phosphate in an organic diluent, washing of the extract uranium nitrate solution containing the reducing agent, and reextraction uranium purification of the extract uranium from technetium (reduction of technetium (VII) and its transfer from the organic phase in water) is carried out in the wash zone of the extraction cascade nitrate solution containing as reducing carbohydrate (KG). The composition of the solution: 0.1 to 0.2 mol/l KG and 0.05 to 0.15 mol/l nitric acid. The flow ratio of organic and aqueous phase in the wash area is 10-15. The spent wash solution is directed to supply the extraction step of the cascade.

Carbohydrazide (synonyms: carbodydesign; dehydrated carbonic acid; 1,3-diaminooctane) - white crystalline substance, soluble in water and dilute nitric acid. KG introduced into the leaching nitrate solution. The reagent has restorative and complexing properties with respect to the multiply charged cations, including Executional, especially in neutral and weak acid environments (F.Kurzer, .Wilkinson. Chemistry of carbohydrazide and thiocarbohydrazide. Chem. Rev., 1970, 70 (1), pp 111-149).

It is known that carbohydrate in redox reactions with polyvalent metals in nitric acid solutions does not form attestation acid (patent RU №2410774, IPC G21C 19/46, publ. 27.01.2011).

Previously studied the kinetics of oxidation KG of hydrazine in solutions with different concentrations of nitric acid at different temperatures.

It is established that the rate constant of the oxidation reaction KG 3-4 times less than the rate constants for the oxidation of hydrazine in the temperature range 20-90°C and the concentration of nitric acid of 0.05-7 mol/L.

The inventive variant of the method was verified on a laboratory extraction booth, hardware technological scheme is presented in figure 1.

As extractant used a 30% solution of TBP in the diluent RED - 1, pre-washed products from the decomposition of solutions of carbonate and sodium hydroxide. Aqueous solutions had the following composition:

The original nitrate solution:

- uranium - 300 g/liter;

- technetium - 10 mg/l;

- nitric acid - 63 g/l

Wash solution:

- carbohydrazide is 0.17 mol/l;

- nitric acid - 0.08 mol/L.

The experiment was performed under the following conditions:

the flow ratio of organic and aqueous phases in the area of extraction (steps 1-6) was 2,33;

- the ratio of the group of threads organic and aqueous phases in the zone of leaching extract (7-10 degrees) was 14;

- the temperature of the solution in the extraction steps 30-32°C.

The duration of the experiment was 12 hours.

In the experiment, every 4 hours, samples were taken of the raffinate and extract uranium at the exit of the cascade (10 step) to determine their composition. The average concentrations of the components in the output solutions were:

The raffinate:

uranium is less than 5 mg/l;

- technetium - 8,5±0,5 mg/l;

- nitric acid - 54±1 g/L.

Extract uranium after washing:

- uranium - 107±2 g/l;

- technetium - less than 0.1 mg/L.

The obtained results show the high efficiency of extraction and purification of uranium from technetium using carbohydrazide in the composition of the leaching nitrate solution.

In the second variant of the proposed method the problem is solved in that in the method of extraction processing of regenerated uranium, including extraction of uranium from nitric acid solution of uranyl nitrate) with tributyl phosphate in an organic diluent, washing of the extract nitric acid solution containing a reducing agent, and reextraction uranium leaching extract uranium nitrate solution containing the reducing agent, and reextraction uranium purification of the extract uranium from technetium (reduction of technetium (VII) and its transfer from the organic phase in water) is carried out in the wash zone of the extraction Cam the hell nitrate solution, containing as reducing carbohydrate. The composition of the solution: 0.1 to 0.2 mol/l KG and 0.05 to 0.15 mol/l nitric acid. The flow ratio of organic and aqueous phase in the wash area is 10-15. The spent leaching solution to extract uranium are contacted in countercurrent with the flow of fresh extractant when the flow ratio of organic and aqueous phases, is equal to 1-1,2, and then is directed to the operation of the conditioning of liquid radioactive waste, and the resulting extract connected to the main uranium extract before serving in the wash zone. The raffinate substantially depleted by technetium compared with the initial solution, refer to the operation for the recovery of nitric acid.

The inventive variant of the method was verified on a laboratory extraction booth, hardware technological scheme is presented in figure 2.

As extractant used a 30% solution of TBP in the diluent RED-1, pre-washed products from the decomposition of solutions of carbonate and sodium hydroxide. Aqueous solutions had the following composition:

The original nitrate solution:

- uranium - 300 g/liter;

- technetium - 10 mg/l;

- nitric acid - 63 g/l

Wash solution:

- carbohydrazide is 0.17 mol/l;

- nitric acid - 0.08 mol/L.

The experiment was performed under the following conditions:

- the ratio of the flow body is systematic and water phases in the area of extraction (steps 1-6) were 2.8;

the flow ratio of organic and aqueous phases in the area of extracting uranium from the spent leaching solution (7-10 degrees) was 1,12;

the flow ratio of organic and aqueous phases in the zone of the washing of the combined extracts (11-14 stage) was 15;

- the temperature of the solution in the extraction steps 30-32°C.

The duration of the experiment was 12 hours.

In the experiment, every 4 hours, samples were taken of the raffinate and extract uranium at the exit of the cascade (14 degree) to determine their composition. The average concentrations of the components in the output solutions were:

The raffinate:

uranium is less than 5 mg/l;

- technetium - less than 0.5 mg/l;

- nitric acid - 50±2 g/l

Extract uranium at the output of the 14 stages:

- uranium - 100±2 g/l;

- technetium - less than 0.1 mg/L.

The spent leaching solution after the operation of the uranium extraction:

uranium is less than 5 mg/l;

- technetium - 49,5±1 mg/l;

- nitric acid - 60±2 g/l

The obtained results show high efficiency of extraction separation of uranium and technetium using nitrate leaching solution containing carbohydrate. The possibility of fractional output of technetium in the thread 5 times smaller than the main stream power. The raffinate after the extraction operation directed to the operation for the recovery of nitrogen to the slots evaporation method.

1. A method of processing a nitric acid solution of regenerated uranium with removal of technetium, including extraction of uranium (VI) with tributyl phosphate in an organic solvent, purification of the extract nitric acid solution containing a reducing agent, and reextraction uranium, characterized in that the purification of the extract uranium from technetium by transfer of technetium in dextrogyrate state carry out in the wash zone of the extraction cascade nitrate solution containing as reducing carbohydrate.

2. The method according to claim 1, characterized in that the washing of the extract uranium is conducted with a solution containing 0.1-0.2 mol/l carbohydrazide and 0.05 to 0.15 mol/l of nitric acid.

3. The method according to claim 1, characterized in that the washing of the extract uranium is carried out at a flow ratio of organic and aqueous phase equal to 10-15.

4. The method according to claim 1, characterized in that the spent washing liquor is sent to the feeding stage extraction cascade.

5. A method of processing a nitric acid solution of regenerated uranium with removal of technetium, including extraction of uranium (VI) with tributyl phosphate in an organic solvent, purification of the extract nitric acid solution containing a reducing agent, and reextraction uranium, characterized in that the purification of the extract uranium from technetium by transfer of technetium in dextrogyrate with the standing exercise in the wash zone of the extraction cascade nitrate solution, containing as reducing carbohydrate, spent after washing, the washing solution are contacted in countercurrent with the flow of fresh extractant for the extraction of uranium and then sent to the operation of the conditioning of liquid radioactive waste, and the resulting extract is added to the original extract uranium before serving in the leaching area.

6. The method according to claim 5, characterized in that the washing of the extract uranium is conducted with a solution containing 0.1-0.2 mol/l carbohydrazide and 0.05 to 0.15 mol/l of nitric acid.

7. The method according to claim 5, characterized in that the washing of the extract uranium is carried out at a flow ratio of organic and aqueous phase equal to 10-15.

8. The method according to claim 5, characterized in that the spent leaching solution are contacted in countercurrent with the flow of fresh extractant when the flow ratio of organic and aqueous phases, is equal to 1-1,2.

9. The method according to claim 5, characterized in that the raffinate from the operation of extraction of uranium is directed to the operation of evaporation for recovery of nitric acid and posleduyushego its use in the flowsheet.



 

Same patents:

FIELD: metallurgy.

SUBSTANCE: procedure consists in stage of introduction of complex forming compound to contact with water medium containing said actinoid and one or more lanthanides. Also, the said complex forming compound in not complexated state is not retained with the said membrane and is capable to form complex with said actinoid containing the said element and at least two molecules of the said complex forming compound, also, complex is capable to be retained with the membrane. Further, there is performed the stage of water medium passing through the membrane for formation of filtrate containing water effluent depleted with said actinoid from one side, and retentate containing the said complex.

EFFECT: avoiding membrane clogging at filtration.

13 cl, 5 dwg, 1 tbl, 3 ex

FIELD: chemistry.

SUBSTANCE: present invention relates to substrate material for complex formation and selective extraction of americium, plutonium, uranium or thorium in their cationic form, which is para-tert-butyl-calix[6]arene of formula (IIA), where R'1 R'3 and R'5, which are identical or different, each separately denotes: (i) a linear or branched C1-6alkyl deposited on a substrate, wherein one of the groups R'1 R'3 and R'5 in the compound of formula (IIA) is a group (ii); (ii) spacer-substrate, where the space is a divalent radical selected from a group comprising aryl(C1-6alkyl)aryl; and the substrate is selected from a substrate which is a copolymer of chloro- or bromo-methylstyrene and divinylbenzene. The invention also relates to a liquid membrane deposited on a substrate for complex formation or selective extraction of americium, plutonium, uranium or thorium in their cationic form, containing para-tert-butyl-calix[6]arene of formula (IA) or (IB), which is dissolved in an organic solvent, having boiling point higher than 60°C and absorbed on a substrate, which is epoxy resin, where R1, R3 and R5, which are identical or different, each separately denotes: (i) a hydrogen atom, (ii) a linear or branched C1-6alkyl.

EFFECT: obtaining novel materials.

7 cl, 8 ex, 2 tbl

FIELD: metallurgy.

SUBSTANCE: procedure consists in production of sample containing uranium and silicon dioxide, in treatment of sample containing uranium and silicon dioxide and in production of material containing dissolved uranium and silicon dioxide. Also, material contains SiO2 over or equal to 100 mg/l. Further, dissolved uranium is extracted from material using at least one strong base anion-exchanging resin of macro-reticular structure. There is obtained uranium containing product in combination with strong-base anion-exchanging resin of macro-reticular structure. Further, uranium containing product is eluted and extracted from combination with strong-base anion-exchanging resin of macro-reticular structure.

EFFECT: increased efficiency of uranium extraction from mediums with high contents of silicon dioxide.

9 cl, 3 tbl, 1 ex

FIELD: metallurgy.

SUBSTANCE: procedure consists in processing refractory ore and concentrates with chlorine at presence of water and complex former in kind of sodium chloride, in converting gold into solution, in separating solution from precipitated sediment, and in washing sediment with water producing flush water. There are processed refractory ore and concentrates with low contents of gold and uranium, where uranium is additionally extracted. Also, for processing there is used chlorine in atomic or molecular state. Chloride or sodium sulphate are used as complex formers. Processing is carried out at weight ratio L:S (liquid: solid) (1-1.5) during 1-2 hours at temperature 20-70°C with simultaneous gold and uranium passing into solution.

EFFECT: simplified process, reduced power expenditures at maintaining high degree of gold and uranium extraction from poor bases and concentrates.

7 cl, 6 tbl, 6 ex

FIELD: metallurgy.

SUBSTANCE: procedure consists in extracting uranium by means of liquid extraction of organic phase of synergy mixture on base of di(2-ethylhexyl)phosphorous acid containing tributylphosphate (TBP) or tributylphosphate together with trialkylamine (TAA) or heteroradical phosphynoxide of composition of oxide of isoamyldioktylphosphyne in organic thinner. Also, while mixing, there is performed simultaneous gradual neutralisation of mixture of phases with mineral acid till there are established balanced values of pH of water phase in interval 5.6-6.6.

EFFECT: increased efficiency of extraction of uranium and molybdenum from carbonate solutions.

3 dwg, 3 tbl, 3 ex

FIELD: metallurgy.

SUBSTANCE: procedure consists in sulphuric acid leaching of uranium. Also source material of 0.1-0.3 mm dimension is subjected to sulphuric acid leaching in autoclave till over 95% of uranium is transited to solution and till degree of pyrite oxidation reaches not less, than 50%. Upon separation of uranium containing solution from a solid phase in form of a cake the latter is conditioned by flotation of valuable metals with sulphydric collector and oxy-ethylated compound at pH 2.5-7.0 thus producing concentrate of valuable metals.

EFFECT: high degree of decomposition of persistent minerals of uranium and pyrite oxidation associating silver and gold and efficient extraction of uranium into water phase and valuable metals into floated concentrate.

17 cl, 1 dwg, 7 tbl, 5 ex

FIELD: metallurgy.

SUBSTANCE: invention refers to procedures for processing chemical concentrate of natural uranium. The procedure consists in dissolving natural uranium in solution of nitric acid, in directing solution to uranium extraction with tri-butyl-phosphate and hydrocarbon thinner, in washing extract with re-extract and in uranium re-extracting. There is dissolved chemical concentrate of natural uranium with increased content of phosphorus and sulphur. Uranium is extracted from solutions with increased concentration of phosphorus and sulphur and with concentration of nitric acid 30÷80 g/l to 60÷75% saturation of extractant with uranium. Also this level of extractant saturation with uranium in the said range in % is maintained not exceeding value equal to (0.3×[HNO3]+51), where [HNO3] is concentration of nitric acid in solution directed to extraction, in g/l.

EFFECT: purification of uranium at minimal uranium losses with raffinate.

2 tbl

FIELD: chemistry.

SUBSTANCE: invention relates to atomic industry and can be applied in technological processes of obtaining uranium tetrafluoride and in production of metallic uranium. Method of obtaining uranium tetrafluoride includes dissolution of uranium dioxide, sedimentation of uranium tetrafluoride from obtained solution by supplying hydrofluoric acid. After that carried out are pulp filtration, sediment washing, drying and burning. Dissolution of uranium dioxide is carried out in mixed solution of hydrochloric and hydrofluoric acids obtaining solution of complex uranium compound with uranium concentration up to 480 g/l. Uranium tetrafluoride from solution is precipitated in form of crystal hydrate by dosed supply of hydrofluoric acid during 15-30 min, without forced heating of reaction medium.

EFFECT: increase of process productivity and reduction of expenditures.

1 ex

FIELD: metallurgy.

SUBSTANCE: procedure consists in crushing and wet crumbling of source raw material producing pulp. Also ore containing brannerite is used as source raw material. Upon wet crumbling pulp is concentrated, leached with sulphuric acid and separated. Upon separation upper discharge is directed to counter flow sorption of uranium, while lower discharge containing brannerite fraction is acidated with sulphuric acid to 40-80 g/l producing acidic pulp with S:L<1:4. Produced acidic pulp is radiated with a flow of accelerated electrons at energy of absorbed radiation dose 1.5-1.6 kgr/s during 4-8 min. Further uranium is leached at mixing and at temperature 60-70°C during 2-3 hours and produced pulp is condensed. Upon condensation there is formed upper discharge which is supplied to source raw material leaching, while lower discharge goes to waste.

EFFECT: extraction of uranium from hard opened brannerite crude ore.

3 cl, 7 tbl, 1 dwg, 2 ex

FIELD: metallurgy.

SUBSTANCE: method includes graining of uranium ore, its sulphatisation by sulfur acid at presence of nitric acid. Additionally nitric acid is fed in amount required for oxidation of sulphides containing in uranium ore. Then received grains are subject to thermal treatment at temperature 200-300°C and leaching by water.

EFFECT: reduction of consumption of mineral acids for reprocessing of uranium ore and in increasing of uranium extraction.

5 ex

FIELD: metallurgy.

SUBSTANCE: conversion method of non-ferrous metal salt involves counterflow extraction of metal from solution of its converted salt with the use as cation-exchange extractant in salt form of solution of organophosphorus acid in inert diluter and re-extraction of non-ferrous metal with converting acid so that re-extract containing converted salt of non-ferrous metal is obtained. As non-ferrous metal there used is cobalt or nickel; extraction is performed from solution of converted salt of cobalt or nickel at concentration of cobalt or nickel in solution 65-80 g/l and pH 4-7 with the use as cation-exchange extractant of 20-50% solution of organophosphorus acid in sodium, potassium or ammonia form. Re-extraction is performed with 0.5-2.0 M solution of converting acid. Number of non-ferrous metals to which the proposed method is applied can also include copper and zinc.

EFFECT: increasing conversion degree at minimum content of impurities and enlarging the range of obtained salts of non-ferrous metals.

5 cl, 8 ex

FIELD: metallurgy.

SUBSTANCE: invention refers to procedures for processing chemical concentrate of natural uranium. The procedure consists in dissolving natural uranium in solution of nitric acid, in directing solution to uranium extraction with tri-butyl-phosphate and hydrocarbon thinner, in washing extract with re-extract and in uranium re-extracting. There is dissolved chemical concentrate of natural uranium with increased content of phosphorus and sulphur. Uranium is extracted from solutions with increased concentration of phosphorus and sulphur and with concentration of nitric acid 30÷80 g/l to 60÷75% saturation of extractant with uranium. Also this level of extractant saturation with uranium in the said range in % is maintained not exceeding value equal to (0.3×[HNO3]+51), where [HNO3] is concentration of nitric acid in solution directed to extraction, in g/l.

EFFECT: purification of uranium at minimal uranium losses with raffinate.

2 tbl

FIELD: metallurgy.

SUBSTANCE: method includes leaching of uranium concentrate by solution of nitric acid, uranium extraction by tributyl phosphate in hydrocarbon solvent. Uranium extraction is implemented up to 85-92% saturation of extragent by uranium. Then it is implemented washing of extract by part of evapoarted reextract, containing 450-500 g/l of uranium, which is implemented in the mode of ultimate (up to 119-120 g/l of uranium) of saturation of extragent by uranium. After washing it is implemented uranium re-extraction. Washing solution, received after washing of uranium extraction is combined with uranium solution from concentrates leaching and after correction by content of nitric acid and uranium mixed solution is directed to extraction. Extract washing is implemented at correlation of flows O:B=(15-20):1. Content of nitric acid in uranium solutions directed to extraction is 0.5-0.8 mole/l.

EFFECT: increasing of uranium purification efficiency from molybdenum.

4 cl, 4 tbl, 1 ex

FIELD: chemistry.

SUBSTANCE: invention refers to extraction methods for metal ion extraction and concentration from aqueous solutions and can be used for zirconium separation from compound ion solutions with hydrogen chlorine acid. Invention rests on zirconium ion ability to be extracted in layer system water - ammonium sulphate - potassium bis-(alkylpolyoxyethylene) phosphate (oxyphos-B), [CnH2n+1+1O(C2H4O)m]POOK, where n=8-10, m=6 in ratio as follows, wt %: ammonium chloride - 10-15; oxyphos-B - 10-15; water - to 100.

EFFECT: possibility for quantitative zirconium ion separation from aqueous solutions thus avoiding application of expensive, fire-hazardous and toxic substances.

2 tbl, 1 dwg, 9 ex

FIELD: chemical industry; nuclear power engineering; methods of re-extraction of vanadium from the organic solution containing its salts with the di-2-ethylhexylphosphoric acid.

SUBSTANCE: the invention is pertaining to the method of re-extraction of vanadium from the organic solution containing its salts with the di-2-ethylhexylphosphoric acid. The invention is dealt with the method of the radiochemical reprocessing of the constructional materials of the thermonuclear reactor on the basis of the vanadium-chromium-titanium alloy with the purpose of extraction of vanadium from the organic solutions containing its salts with di-2- ethylhexylphosphoric acid. The re-extraction of vanadium from such solutions is exercised with the help of the nitric acid solutions at the acid concentration of no more than 0.5 mole per liter, containing hydrogen peroxide in amount of no less than 2.5 mole per one mole of vanadium. The technical result of the invention is the decreased duration of the process of the vanadium re-extraction with its simultaneous purification from the rare-earth elements.

EFFECT: the invention ensures the decreased duration of the process of the vanadium re-extraction with its simultaneous purification from the rare-earth elements.

2 tbl, 2 ex

FIELD: inorganic chemistry, chemical technology.

SUBSTANCE: invention relates to technology for producing rare and scattered elements. Invention proposes using a mixture of isododecylphosphetanic and dialkylphosphinic acid in organic solvent as an extractant. Invention provides enhancing selectivity of extraction by metal-impurities and separation of indium from gallium, and possibility for carrying out re-extraction of metals from organic phase with sulfuric acid solutions in the concentration 200-350 g/dm3. Invention can be used in extraction and separation of gallium and indium from acid sulfate solution of the complex composition.

EFFECT: improved separating method.

4 tbl, 4 ex

FIELD: technology of non-ferrous, rare and trace rare metals.

SUBSTANCE: proposed method includes extraction and separation of arsenic by organic extracting agent. Extracting agent is prepared from mixture of dialkyl methyl phosphonate in the amount of 40-70% with trialkyl amine in the amount of 20-30 vol-% and inert diluting agent in the amount of 10-30%. At extraction, arsenic changes to organic phase.

EFFECT: increased degree of extraction of arsenic (+5); enhanced selectivity and economical efficiency.

5 tbl, 6 ex

FIELD: chemistry.

SUBSTANCE: extractant has bi-phosphorus acid and additionally has tri-phosphate with relation of said components (0,5-1,25):1. Method for producing extractant includes adding to 2-ethylhexanole of chlorine oxide of phosphorus with their relation (4,5-5,1):2,0, and with parameters determined by reaching fullness of passing of reaction, after that reaction mixture is exposed until full removal of formed chlorine hydrogen, then to received mixture 1 mole of water is added, mixture is exposed to full hydrolysis. Then mixture is washed ad water layer is separated from organic remainder, containing said bi-phosphoric acid and tri-phosphate.

EFFECT: higher efficiency.

2 cl, 1 dwg, 2 tbl, 4 ex

The invention relates to hydrometallurgy of rare and trace elements and can be used for extraction of the extraction and concentration of indium from zinc sulfate solutions

The invention relates to processes for extraction allocation of actinides from nitric acid solutions reprocessing plants

FIELD: chemistry.

SUBSTANCE: extractant has bi-phosphorus acid and additionally has tri-phosphate with relation of said components (0,5-1,25):1. Method for producing extractant includes adding to 2-ethylhexanole of chlorine oxide of phosphorus with their relation (4,5-5,1):2,0, and with parameters determined by reaching fullness of passing of reaction, after that reaction mixture is exposed until full removal of formed chlorine hydrogen, then to received mixture 1 mole of water is added, mixture is exposed to full hydrolysis. Then mixture is washed ad water layer is separated from organic remainder, containing said bi-phosphoric acid and tri-phosphate.

EFFECT: higher efficiency.

2 cl, 1 dwg, 2 tbl, 4 ex

Up!