Method of processing chemical concentrate of natural uranium

FIELD: chemistry.

SUBSTANCE: method involves dissolving a chemical concentrate of natural uranium in nitric acid solution, extracting and re-extracting uranium. The dissolved concentrate contains 1.2-3.7 wt % iron to uranium, 1.4-4.0 wt % sulphur to uranuim and 0-0.7 wt % phosphorus to uranium in nitric acid solution. Nitric acid and water are taken in an amount which provides the following concentration in the solution fed for extraction: uranium 450-480 g/l, iron (III) ions 0.1-0.3 mol/l, sulphate ions 0.2-0.6 mol/l, phosphate ions 0-0.10 mol/l, and free nitric acid 0.8-2.4 mol/l, and saturation of extractant with uranium during extraction is maintained in accordance with the ratio: Y ≤90.691-34.316·[SO4]+7.611·([Fe]-[PO4])+5.887·[HNO3]-9.921·[SO4]·[HNO3]+19.841·[SO4]2+7.481·([Fe]-[PO4])·[HNO3]-64.728·([Fe]-[PO4])·[SO4]+92.701·[SO4]·[HNO3]·([Fe]-[PO4])-185.402·[SO4]2·([Fe]-[PO4]), where Y is saturation of the extractant with uranium, %, and concentration in the solution fed for extraction, mol/l: [SO4] - sulphate ions, [PO4] - phosphate ions, [HNO3] - nitric acid, [Fe] - iron (III) ions.

EFFECT: obtaining raffinates with low uranium content.

1 tbl

 

The invention relates to the technology of chemical processing of natural uranium concentrates (NUC)with high content of sulfur and iron, and possibly phosphorus, using tributyl phosphate (TBP) in a hydrocarbon diluent.

It is known (V.B. have been Shevchenko, BN. Sudarikov. The technology of uranium. M: gosatomizdat, 1961, s)that the extraction of uranyl nitrate by tributyl phosphate is rapidly deteriorating in the presence in solution of a number of anions, forming with uranium complex compounds, for example, phosphate and sulfate ions in a concentration of about 0.1÷0,2 N and more. Their negative influence on the extraction efficiency due to decrease in the distribution coefficient of uranyl nitrate between organic and aqueous phases, which leads to an increase in the concentration of uranium in the raffinate.

The known method (Including Harrington, A. Rule. Production technology of uranium. M. Amsterdam: North. 1961, pp.178÷181) processing NUC, including extraction of uranium from the pulp. The extraction was carried out until saturation of uranium extractant 95 g/l (79%saturation of uranium extractant). The concentration of nitric acid, depending on the content of sulphates, supported within 0,8÷1.8 mol/L. raffinate contains uranium less than 0.1 g/L.

A method of refining NUC with a high content of phosphorus and sulfur (patent No. 2398036, IPC SW 60/02, SW 3/06, SW 3/38 (2006.01), publ. 27.08.2010), vkljuchajuwih the extraction of uranium from solution. Extraction of uranium lead from solutions with concentrations of nitric acid 30÷80 g/l to saturation of uranium extractant 60÷75%, while the amount of saturation of the extractant uranium in the specified interval, in %, may not support higher values (0,3×[HNO3]+51), where [HNO3] is the concentration of free nitric acid in the initial aqueous solution used for extraction, in g/L. the Method chosen for the prototype.

Known methods include the effect of certain impurities by extraction. However, the joint effect of several impurities (ferric ions, sulfate ions, phosphate ions), their increased content on the extraction of uranium in the extract and thus for the remainder of the uranium in the raffinate in the known methods do not take into account.

On the uranium market as the NUC is regulated by the international standard for uranium ore concentrates With ASTM 967-08. In accordance with this standard iron content, as a rule, is not more than 0.15 wt. % uranium, sulfur is not more than 1.0 wt.% for uranium, phosphorus - not more than 0.1 wt.% to Uranus (the so-called limits "without penalty"). This standard allows high concentrations of iron, sulfur and phosphorous in concentrate uranium, namely: up to 1.0 wt.% to Uranus for iron, up to 4.0 wt.% to Uranus for sulfur and up to 0.7 wt.% to Uranus for phosphorus (so-called "no rejection", which provides an additional fee for re is abotu concentrate).

In practice, in some cases, manufacturers NUC implement concentrate more impurities, such as iron, to 3.7 wt.% to Uranus.

The task of the invention to provide a waste uranium refined to uranium content in the raffinate < 0.07 g/l in the processing of concentrates of uranium with a high content of impurities of iron, sulfur, and possibly phosphorus. This should be provided with the necessary purification of uranium from impurities, i.e., the uranium must be cleaned to the requirements of the international standard ASTM C787-03 for uranium hexafluoride for enrichment.

The set task is solved by the fact that in the method for processing chemical concentrate of natural uranium, including its dissolution in nitric acid solution, the extraction of uranium by tributyl phosphate in a hydrocarbon diluent and reextraction uranium dissolution is subjected to uranium concentrate with a high content of iron, sulfur, and possibly phosphorus, namely: iron 1,2÷3.7 wt.% for uranium, sulfur 1,4÷4.0 wt.% the uranium and phosphorus 0÷0.7 wt.% to Uranus, with water and nitric acid charge in an amount to provide a concentration in the solution used for extraction,: uranium 450÷480 g/l ferric ions 0,1÷0,3 mol/l, the sulfate ions of 0.2÷0.6 mol/l phosphate ions 0÷0.10 mol/l, free of nitric acid 0,8÷2.4 mol/l, and the saturation of uranium extractant in the extraction process support the claim in accordance with the equation:

Y≤90,691-34,316·[SO4]+7,611·([Fe]-[PO4])+5,887·[HNO3]-9,921·[SO4]·[HNO3]+19,841·[SO4]2+7,481·([Fe]-[RHO4])·[HNO3]-64,728·([Fe]-[PO4])·[SO4]+92,701·[SO4]·[HNO3]·([Fe]-[PO4])-185,402·[SO4]2·([Fe]-[PO4]),

where Y is the saturation of the extractant uranium %, and the concentration in the solution used for extraction, mol/l: [SO4] - sulfate ions, [PO4] - phosphate ions, [HNO3] - nitric acid, [Fe] - ions of trivalent iron.

Experiments were conducted that determined the effect of impurities and their quantities on the extraction of uranium in the extract and thus the uranium content in the refined. Experiments have shown that in the case of solutions used for extraction, with concentrations in the intervals: uranyl nitrate in terms of uranium 450÷480 g/l ferric ions 0,1÷0,3 mol/l, the sulfate ions of 0.2÷0.6 mol/l phosphate ions 0÷0.10 mol/l, and free nitric acid 0,8÷2.4 mol/l, it is necessary to achieve the uranium content in the raffinate < 0.07 g/l, to support the extraction of the following degree of saturation of the "uranium extractant:

For other concentrations, are not included in the above intervals, the degree of saturation of the "U"corresponding to the given value (I), does not provide specified waste uranium content in refined.

At Azania concentration of impurities and acid in the solution provide by dissolving concentrates with iron content of 1.2÷3.7 wt.% for uranium, sulfur 1,4÷4.0 wt.% the uranium and phosphorus to 0.7 wt.% the uranium in nitric acid solutions of a given concentration.

The method is as follows.

Processed NUC with high content of iron, sulfur, and possibly phosphorus, namely, with an iron content of 1.2÷3.7 wt.% for uranium, sulfur 1,4÷4.0 wt.% the uranium and phosphorus to 0.7 wt.% to Uranus.

The uranyl nitrate solution was prepared by dissolving NUC with the specified content of impurities in nitric acid solution of a given concentration and is separated from the insoluble residue by decantation; for the preparation of a solution of acid and water charge in an amount to provide a concentration in the solution used for extraction,: uranyl nitrate in terms of uranium 450÷480 g/l ferric ions 0,1÷0,3 mol/l, the sulfate ions of 0.2÷0.6 mol/l phosphate ions 0÷0.10 mol/l, free of nitric acid 0,8÷2.4 mol/L.

The extraction was carried out at a given temperature 30%TBP in a hydrocarbon solvent from a solution with a high content of ferric ions and sulfate ions, and in some cases, the phosphate ions. The degree of saturation of the extractant uranium "was provided by a given ratio of the phases O:P

The extract was washed and the washed extract was sent to reextraction.

The results of the experiments are shown in the table.

In experiments 1-13, when the content in the uranyl nitrate solution impurities of the nitric acid in the inventive range and degree of saturation of uranium extractant, corresponding to the ratio of (I), obtained refined with a uranium content of below 0.07 g/L. When the degree of saturation, not corresponding to the ratio of (I)discharges of uranium raffinate exceed 0.07 g/L.

In experiments 14-15, when the content of nitric acid in the original solution of uranyl nitrate, beyond the interval of 0.8-2.4 mol/l, the values of the saturation degree, whilst conforming to the ratio of (I), but does not provide waste uranium (below 0.07 g/l) refined.

Table
no experienceThe original solution, mol/lExtractThe raffinate [U], g/l
[SO4][HNO3][Fe][PO4]saturation, %[U], g/l
10,200,800,30094,9to 121.611,2
85,419,4 0,07
1 est.Y≤90,2Y≤115,5-
20,200,800,10095,4122,216,4
88,6to 113.40,07
82,6105,80,07
2 calc.Y≤88,6From≤to 113.4-
30,201,000,30096,1123,18,2
92,5118,50,07
89,2114,30,07
3 calc.Y≤92,5-
40,201,000,100a 94.2120,75,3
78,1100,10,07
4 calc.Y≤89,9The≤or 115.1-
50,601,800,10084,8108,6the 4.7
78,7100,80,07
71,091,00,07
5 calc.Y≤78,7Y≤100,8-
60,601,800,30 0of 87.8112,516,3
71,091,00,07
6 calc.Y≤81,8Y≤104,8-
70,201,600,30099,5127,50,07
91,0116,60,07
7 calc.Y≤99,5Y≤127,5-
80,201,600,10099,7127,719,2
88,3113,1<0,07
8 calc.Y≤93,8Y≤320,1 -
90,602,400,10092,5118,53,6
82,4105,60,07
78,9101,1<0,07
9 calc.Y≤82,4Y≤305,6-
100,602,400,30095,9122,95,2
86,4to 110.70,07
10 calc.Y≤br93.1Y≤19,3-
110,401,700,200 93,0119,13,2
89,0114,00,07
82,4105,60,07
11 calc.Y≤89,0Y≤114,0-
120,401,700,200,02791,9117,72,7
88,2level 113.00,07
79,2of 101.50,07
12 calc.Y≤88,2Y≤13,0-
130,401,700,200,100to 92.1118,04,1
86,2 110,40,07
78,099,90,07
13 calc.Y≤86,2Y≤310,4-
140,600,600,10081,9104,9of 31.4
71,291,23,2
68,087,10,41
14 calc.Y≤71,2Y≤91,2-
150,602,600,30097,6125,012,8
96,9of 124.11,7
93,8120,2 0,14
15 est.Y≤96,9Y≤of 124.1-

In reextractors uranium experiments 1÷13 contents of all ballast impurities was less than the values given in ASTM C787-03 for uranium hexafluoride for enrichment, i.e. provided with the necessary purification of uranium.

Method for processing chemical concentrate of natural uranium, including the dissolution in an aqueous solution of nitric acid, extraction of uranium from solution of tributyl phosphate in the hydrocarbon diluent and reextraction uranium, characterized in that the dissolution of exposed uranium concentrate with an iron content of 1.2÷3.7 wt.% for uranium, sulfur 1,4÷4.0 wt.% the uranium and phosphorus 0÷0.7 wt.% for uranium, while the dissolution of water and nitric acid taken in the quantity that is directed to the extraction of nitric acid solution of uranyl nitrate concentrations: uranium 450÷480 g/l ferric ions 0,1÷0,3 mol/l, the sulfate ions of 0.2÷0.6 mol/l phosphate ions 0÷0.10 mol/l and free nitric acid 0,8÷2.4 mol/l, and the saturation of uranium extractant in the extraction process support in accordance with the ratio:
Y≤90,691-34,316·[SO4]+7,611·([Fe]-[PO4])+5,887·[HNO3]-9,921·[SO4]·[HNO3]+19,841·[SO4]2+7,481·([Fe]-[PO4])·[HNO3]-64,728·([Fe]-[PO4])·[SO4]+92,701·[SO4 3]·([Fe]-[PO4])-185,402·[SO4]2·([Fe]-[PO4]), where Y is the saturation of the extractant uranium %, and the concentration in the solution used for extraction, mol/l: [SO4] - sulfate ions, [PO4] - phosphate ions, [HNO3] - nitric acid, [Fe] - ions of trivalent iron.



 

Same patents:

FIELD: metallurgy.

SUBSTANCE: method includes sorption of rich components from production solutions by ion-exchange material counterflow under controlled pH of environment and oxidation-reduction potential Eh. Sorption is performed by ion-exchange materials in stages from production solutions containing uranium, molybdenum, vanadium and rare earth elements. At the first stage uranium and molybdenum are extracted by anion-exchange material sorption. At the second stage vanadium is extracted by anion-exchange material sorption with hydrogen dioxide available at Eh of 750-800 mV, pH of 1.8-2.0 and temperature of 60°C, at that vanadium sorption is performed till complete destruction of hydrogen dioxide and till Eh is below 400 mV. Then barren solutions are transferred to cationite at pH of 2.0-2.5 and Eh of 300-350 mV for extraction of rare earth elements.

EFFECT: sorption concentration and selective separation of uranium and molybdenum from vanadium, and vanadium from rare earth elements, and rare earth elements from iron and aluminium, intensification of sorption process, reduction of flow diagram and possibility of environmentally sound oxidants use.

1 dwg, 4 tbl, 1 ex

FIELD: metallurgy.

SUBSTANCE: processing method of black-shale ores includes crushing, counterflow two-stage leaching by sulfuric acid solution upon heating, separation of pulps formed after leaching at both stages by filtration. Then valuable soluble materials are washed from deposit at the second stage with strengthened and washing solutions being produced, marketable filtrate is clarified at the first stage for its further processing. Ore is crushed till the size of 0.2 mm, leaching at the first stage is performed by cycling acid solution with vanadium under atmospheric pressure, temperature of 65-95°C during 2-3 hours, till residual content of free sulphuric acid is equal to 5-15 g/l. Leaching at the second stage is performed at sulphuric acid rate of 9-12% from the quantity of initial hard material under pressure of 10-15 atm and temperature of 140-160°C during 2-3 hours. Cake filtered after the first stage is unpulped by part of strengthened solution which content is specified within 35-45% of total quantity.

EFFECT: high-efficiency extraction of rich components, possibility of pulps separation by filtration after leaching with high properties thus reducing costs for separation processes.

3 cl, 1 dwg, 1 tbl

FIELD: metallurgy.

SUBSTANCE: processing method of black-shale ores with rare metals extracting includes leaching of ore by sulphuric acid solution with dilution of rare metals. Leaching is performed in autoclave by sulphuric acid solution consisting of free and combined sulphuric acid with ratio of H2SO4(free):H2SO4(comb)=2:1, and containing 25-45 g/l of iron sulphate, 70-90 g/l of aluminium sulphate and 0.5 g/l of nitric acid. At that the process is performed under pressure in autoclave equal to 10-15 atm with mixing at temperature of 140-160°C in concentration range of general H2SO4(gen) equal to 350-450 g/l under pulp density S: L=1:0.7-0.9, preferably 1:0.8, under constant oxidation-reduction potential Eh in the system equal to 350-450 mV during 2-3 hours till residual concentration of free H2SO4(free) is within 45-75 g/l.

EFFECT: increasing break-down of ore and extraction of rare metals: vanadium, uranium, molybdenum and rare-earth elements, reducing consumption of acid and improving efficiency of autoclave volume usage.

1 tbl, 1 ex

FIELD: chemistry.

SUBSTANCE: invention relates to the technology of processing chemical concentrates of natural uranium, involving leaching (dissolving) the concentrate and extracting uranium using tributyl phosphate in a hydrocarbon diluent. The method involves dissolving the concentrate using aqueous nitric acid solution, feeding the obtained aqueous uranyl nitrate solution to the extract outputting step of a stepped extraction unit and extracting uranium with tributyl phosphate in a hydrocarbon diluent. Extraction is carried out by counterflow interaction of the aqueous and organic phases. Concentrate containing thorium impurities in ratio of 1 wt % to uranium is used. During extraction at the extract outputting step, the step for saturating the extractant with uranium is kept at least 87% of the maximum saturation of the extractant with uranium, and a portion of the aqueous phase, which is not more than 60 vol. % of the uranyl nitrate solution fed to the extract outputting step, after one of the extraction steps is removed from the extraction process and fed for dissolving the uranium concentrate.

EFFECT: high extraction of uranium and nitric acid from the raffinate.

1 tbl

FIELD: metallurgy.

SUBSTANCE: method involves use of an unbalanced solution consisting of a solution from the washing process of anionite from the acid and filtrate from the filter press, and their removal from the process together with a mother solution from deposition of natural uranium concentrate through an additional saturation operation together with a marketable reclaimed product. For that purpose, the plant includes a local solution recirculation circuit in the form of a collector for solutions of unbalanced and mother concentrate from deposition, which is connected to pipelines of the above solutions and equipped with solution supply pipelines attaching the collector through a gravity tank to an additional saturation column from the marketable reclaimed product and to a solution return pipeline attaching the gravity tank to the solution collector of the local solution recirculation circuit.

EFFECT: reduction of nitrate ions emissions; reduction of prime cost of end product and compliance with strict environmental requirements.

2 cl, 2 dwg, 1 tbl, 2 ex

FIELD: metallurgy.

SUBSTANCE: method involves leaching of uranium and iron using sulphuric acid solution and ferric iron contained in the ore as an oxidiser. After leaching is completed, uranium is extracted from the solution so that mother solution containing ferrous iron is obtained. Then, acidification of the mother solution is performed using sulphuric acid and recovery of ferric iron is performed by oxidation of ferrous iron so that a reusable solution is obtained, and recirculation of that solution for leaching of uranium is performed. Recovery of ferric iron is performed by action on the mother solution of high-voltage pulse electric discharges at high voltage pulse amplitude of not less than 10 kV and at pulse repetition cycle at the interval of 400÷1400 pulse/sec. At that, prior to action on mother solution with high-voltage pulse electric discharges, it is subject to dispersion.

EFFECT: reduction of power consumption and capital costs.

1 dwg, 2 tbl, 1 ex

FIELD: metallurgy.

SUBSTANCE: proposed process comprises crushing and grinding the ore, sulfuric acid leaching with addition of nitrogen acid as an oxidiser. Then, uranium is extracted and cleaned of impurities with the help of extractive agents mix to wash saturated extractive agent with the solution of sulfuric acid. After extraction, uranium is re-extracted to obtain uranium concentrate by means of 8-10%-solution of sodium carbonate. Uranium is deposited from re-extracted product by hydrogen peroxide with 50-100%-surplus from stoichiometry at equilibrium pH 3.6-4.2, mixing interval of 1- 1.5 h and sedimentation time of, at least, 1 h.

EFFECT: high quality finished uranium protoxide-oxide product.

4 tbl, 4 ex

FIELD: chemistry.

SUBSTANCE: invention relates to methods of extracting americium in form of americium dioxide from solutions. The invention can be used in the technology of extracting americium from production and radioactive wastes. The method involves concentrating nitric acid solution containing americium and impurities to americium content of not less than 100 mg/l by multi-step deposition of a precipitate containing americium, followed by dissolution thereof each time in a new portion of the starting solution. The precipitate containing americium is obtained from each portion of the solution by adding to 3.8-6.0 M nitric acid solution, which contains americium and impurities, ammonium hydroxide or an alkali metal hydroxide until achieving residual acidity of 0.1-0.2 M, oxalic acid to concentration of 10-50 g/l and adjusting acidity of the obtained reaction mixture to pH 0.6-2.3 if there are hydrolysable impurities in the starting solution and to pH 0.6-3.5 if not. The precipitate obtained by deposition from the americium-concentrated solution is then calcined and the calcined precipitate is then dissolved in nitric acid solution. Americium is then extracted from the obtained solution by a tributyl phosphate-based solid extractant, re-extracted, americium oxalate is deposited from the re-extract and then calcined to americium dioxide.

EFFECT: wider range of methods of extracting americium.

3 cl, 2 ex

FIELD: metallurgy.

SUBSTANCE: invention refers to complex processing method of carbon-silicic black-shale ores, which contain vanadium, uranium, molybdenum and rare-earth elements. The above method involves ore crushing to the particle size of not more than 0.2 mm and two leaching stages. Oxidation sulphuric-acid leaching is performed at atmospheric pressure. Autoclave oxidation sulphuric-acid leaching is performed at the temperature of 130-150°C in presence of oxygen-containing gas and addition of a substance forming nitrogen oxide, as a catalyst of oxygen oxidation. Ion-exchange sorption of uranium, molybdenum, vanadium and rare-earth elements is performed from the obtained product solution.

EFFECT: increasing extraction degree of vanadium, uranium, molybdenum; improving the complexity of ore use owing to associated extraction of rare-earth elements.

18 cl, 1 dwg

FIELD: metallurgy.

SUBSTANCE: method includes uranium sorption by anion exchange resin, uranium de-sorption from saturated anion exchange resin by sulphuric acid and obtaining finished product from strippant. Note that uranium de-sorption from saturated anion exchange resin is done by sulphuric acid solution with concentration 70-100 g/l with the presence of 1-2 mole/l of ammonia sulphate.

EFFECT: decrease of sulphuric acid content in desorbing solution and rich eluate and reduction of sulphuric acid consumption, decrease of desorbing solution flow and anion exchange resin ratio at de-sorption, increase of uranium content in rich eluate at decrease of rich eluate volume and decrease of uranium residual content by 1-2 levels in anion exchange resin after de-sorption.

1 tbl, 3 ex, 2 dwg

FIELD: chemistry.

SUBSTANCE: invention relates to technology of rare metals, in particular to hydrometallurgy of zirconium and hafnium. Method of zirconium and hafnium separation includes obtaining zirconium and hafnium hydroxides at temperature, not higher than 30-35°C, dehydration of obtained zirconium and hafnium hydroxides, their dissolution in nitric acid and following extraction of zirconium by tributylphosphate extraction from obtained solution in backflow, water phase is removed from cell in the middle of cascade, nitric acid is added to it, and obtained solution is introduced into the following stage downstream water phase movement.

EFFECT: invention ensures increase of zirconium separation, increase of cascade work stability and reduction of nitric acid consumption.

4 cl, 5 tbl, 3 ex

FIELD: chemistry.

SUBSTANCE: invention relates to the technology of processing chemical concentrates of natural uranium, involving leaching (dissolving) the concentrate and extracting uranium using tributyl phosphate in a hydrocarbon diluent. The method involves dissolving the concentrate using aqueous nitric acid solution, feeding the obtained aqueous uranyl nitrate solution to the extract outputting step of a stepped extraction unit and extracting uranium with tributyl phosphate in a hydrocarbon diluent. Extraction is carried out by counterflow interaction of the aqueous and organic phases. Concentrate containing thorium impurities in ratio of 1 wt % to uranium is used. During extraction at the extract outputting step, the step for saturating the extractant with uranium is kept at least 87% of the maximum saturation of the extractant with uranium, and a portion of the aqueous phase, which is not more than 60 vol. % of the uranyl nitrate solution fed to the extract outputting step, after one of the extraction steps is removed from the extraction process and fed for dissolving the uranium concentrate.

EFFECT: high extraction of uranium and nitric acid from the raffinate.

1 tbl

FIELD: chemistry.

SUBSTANCE: method involves leaching the concentrate with aqueous nitric acid solution at high temperature to obtain a pulp consisting a solid and an aqueous phase. The aqueous phase is then separated by filtration from the solid phase in form of uranium nitrate solution. Uranium is then extracted from the nitrate solution using tributyl phosphate in a hydrocarbon solvent. The extract is washed and uranium is re-extracted. Leaching is carried out by adding nitric acid and water in an amount which enables to obtain a nitrate solution in the aqueous phase of the pulp, said nitrate solution containing dissolved silicon in concentration of 2.5-3.7 g/l. The solid phase, which consists of insoluble concentrate residues, is separated by filtration from the solution which contains dissolved silicon, uranium in concentration of 170-250 g/l and nitric acid in concentration of 80-120 g/l. Filtration is carried out not more than 24 hours after leaching, preferably not more than 5 hours after leaching.

EFFECT: obtaining clean nuclear materials, suitable for producing uranium hexafluoride for enrichment.

2 tbl, 2 ex

FIELD: chemistry.

SUBSTANCE: method involves leaching in order to dissolve uranium when the concentrate reacts with nitric acid solution to obtain pulp from the concentrate. Uranium is then extracted from the pulp using tributyl phosphate in a hydrocarbon solvent. The extract is washed and uranium is re-extracted. Extraction is carried out from freshly prepared pulp which is obtained through direct-flow reaction at temperature 20-65°C of a stream of a suspension of the concentrate in water which is prepared beforehand and a stream of nitric acid solution with flow rate ratio which ensures nitric acid concentration in the pulp of 25-120 g/l. The period from the beginning of leaching to the beginning of extraction is not more than 10 minutes.

EFFECT: protection of extraction from formation of non-demixing emulsions, providing given purity of uranium from ballast impurities and obtaining raffinates which can be removed into underground collector sand layers.

2 tbl, 1 ex

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

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: 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!