Method of processing natural uranium chemical concentrate
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Method of processing chemical concentrate of natural uranium / 2447168 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. |
 Method of processing chemical concentrate of natural uranium / 2444576Method 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. |
 Method of converting waste uranium hexafluoride into uranium metal / 2444475Invention relates to ecology and is aimed at preventing environmental pollution and radiation poisoning. The method of converting waste uranium hexafluoride into uranium metal and calcium fluoride involves reaction of uranium hexafluoride and calcium metal, where gaseous uranium hexafluoride is fed into molten calcium metal by bubbling, and operating temperature is kept higher than the melting point of calcium fluoride. |
 Method for extracting rare metals from ash-slag masses of used underground gas generator / 2443788Intensified extraction of underground water is performed from used underground gas generator through the main water drain wells. Then, there created is cone of depression in the section of used underground gas generator for minimisation of underground water level and maintenance of maximum depression in the section of used underground gas generator. Treatment of ash-slag masses is performed using the solvent injected to the used underground gas generator, and leaching and collection of rare metal dissolved in the solvent extracted from underground gas generator is performed in surface chemical complex. |
 Procedure for processing uranium ore / 2434961Silicate uranium ore is crushed and crumbled; further, it is leached with sulphuric acid with addition of nitric acid as oxidant. Uranium is extracted and refined from impurities using mixture of extragents. Also as mixture of extragents there is used synergetic mixture containing di(2-ethyl-hexyl)phosphoric acid - 0.05-0.075 mole/l, tri-alkyl-amine - 0.05-0.075 mole/l in hydrocarbon dissolver at ratio of volumes of organic and water phases VO-VW= 1-3÷6. Upon extraction organic phase saturated with uranium is washed with solution of sulphuric acid. Further, uranium is re-extracted with solution of coal-ammonia salts producing crystals of ammonia-uranyl-tri-carbonate and is filtered. Produced crystals are tempered to production of protoxide-oxide of uranium. |
 Processing method of nitric-acid solution of regenerated uranium with removal of technetium (versions) / 2430175Processing 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. |
 Procedure for separation of actinoide from lanthanide in water medium by complexation and membrane filtration / 2427658Procedure 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. |
![Para-tert-butyl-calix[6]arenes, containing three acid functional groups in positions 2, 4 and 3, liquid membranes deposited on substrate, substrate materials containing said membranes and use thereof](http://img.russianpatents.com/img_data/942/9427017-s.gif) Para-tert-butyl-calix[6]arenes, containing three acid functional groups in positions 2, 4 and 3, liquid membranes deposited on substrate, substrate materials containing said membranes and use thereof / 2422432Present 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 |
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Procedure for extraction of uranium / 2412266 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. |
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Procedure for processing refractory ore and concentrates / 2412262 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. |
 Method of processing manganese-containing material / 2448175Method involves transfer of manganese and accompanying impurities into a solution through two-step treatment of the starting material with hydrochloric acid and absorption of chlorine with an alkaline solution. Further, impurities are separated to obtain a manganese salt solution which is then treated. The first step uses waste hydrochloric acid with concentration 1-10% with solid to liquid ratio equal to 1:(3-5). A manganese-containing residue is separated from the obtained pulp, where said residue is then treated at the second step with waste inhibited hydrochloric acid with concentration 20-24% and content of inhibitor of not less than 5 wt %, reaction with iron of which results in insoluble complex compounds, where said inhibitor is in form of quaternary ammonium salts, with molar ratio manganese:HCl=1.0:1.1. The insoluble residue of aluminosilicates is then separated and the manganese salt solution is then processed using existing methods. |
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Procedure for extraction of nickel from solutions and for purification from impurities / 2430981 Procedure for extraction of nickel from solutions and purification from impurities: Cr3+, Fe3+, Al3+, Cu2+, Zn2+, Co2+, Fe2+, Mn2+, Ca2+, Mg2+ consists in bringing pH of solutions to values 4.0-6.5, in sorption of nickel at pH=4.0-6.5 from solutions or pulps on sub-acid cationites, in desorption of nickel from saturated cationites with solution of sulphuric or hydrochloric acid with production of solution of nickel strippant. Before desorption saturated cationite is treated with solution of nickel purified from impurities, also with portion of solution of strippant with concentration of nickel higher, than its concentration in source solution or pulp coming to sorption at a value of pH less, than pH of solution or pulp in the process of sorption. Ratio of CNI:ΣCimpurity in solution of strippant changes from 7:1 to 500:1. |
 Method of extracting copper (ii) ions from ammonia media using beta-n-oxyethylhydrazides of aliphatic carboxylic acids / 2422437Invention relates to a novel method of removing copper (II) ions from water in the presence of ammonia, which is based on using a floatation reagent in form of β-N-oxyethylhydrazides of aliphatic carboxylic acids of formula |
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Method of producing of metal iridium powder from (trifluorophosphine) iridium hydride tetrakis / 2419517 Invention relates to method of producing iridium from (trifluorophosphine) iridium hydride tetrakis and may be used for production of high-purity metal iridium powder. Proposed method comprises ammonolysis of volatile complex compound of (trifluorophosphine) iridium hydride tetrakis Hlr(PF3)4 with conversion into nonvolatile iridium metallamine by water solution of ammonium. Then, iridium metallamine is dissolved in concentrated hydrogen nitrate and solution is evaporated. Evaporation over, residue is decomposed to sponge-structure metal iridium. Now, the latter is triturated, reduced in hydrogen flow and purified to high-purity iridium. |
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Procedure for purification of sulphate solution from impurities / 2411296 Procedure for purification of zinc sulphate solution from impurities consists in hydrolytic purification with preliminary iron oxidisation in two stages: first with diluted solution of hydrogen peroxide at temperature 20-55°C and consumption 0.95-1.1 of stoichiometric required amount, then with manganese dioxide contained in electrolytic slime of zinc production. |
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Method of processing nitration hydroxides in refinery of platinum metals / 2410451 Invention relates to metallurgy of noble metals, in particular, to method of processing nitration hydroxides in refinery of platinum metals containing chalcogenides, tin, arsenium and platinum group metals, gold and silver. Proposed method comprises leaching of hydroxides and extracting basic metal compounds from the solution. Hydroxide leaching is carried out for 1-2 h by alkali solution with concentration of 140-180 g/l with l:S ratio varying from 3:1 to 4:1, temperature 80-90°C, and introducing hydrazine hydrate into pulp to reach OVP of minus 400-600 mV relative to reference silver-chloride electrode. Then, alkaline solution is separated from insoluble residue that concentrates platinum metals. Now, extraction of basic metals is carried out in processing alkaline solution by sulfuric acid to pH=4-5 to produce hydroxide precipitate of tin, arsenium, selenium and tellurium, and by filtration, or processing of alkaline solution by sulfuric acid to pH 0.5-1.0 along with adding iron powder to OVP varying from 0 to minus 100 mV, and filtration of obtained cementates obtained on the basis of selenium and tellurium, and processing the solution by alkali to pH = 4-5 with deposition of tin and arsenium hydroxides. Invention allows extracting up to 85% of Se and Te into target products, 90% of Sn and As into secondary hydroxides at minimum transition (less than 1%) into PMH. |
 Procedure for extracting metal from mineral ore containing refractory ore in barren rock and installation for implementation of this procedure / 2407814Procedure consists in concentrating refractory ore with successive concentrate fine crumbling to release gold with extracting solution and in mixing fine crumbled concentrate with wastes or by-products of concentrating to facilitate filtering said concentrate mixed with said wastes of concentrating. Here is also disclosed the installation for implementation of the said procedure. |
 Method of extracting noble metals from aqueous solutions and device for realising said method / 2404927Electrosorption carbon material is the cathode and is carbon fibric on which there is a layer a conducting polymer - poly-3,4-ethylenedioxythiophene or polyaniline which can chemically reduce ions of noble metals Ag, Au and Pd to metal state. Before passing the aqueous solution to the electrosorption carbon material, a negative potential between -0.5 and -0.3 V is applied relative a silver chloride electrode. Reduction takes place upon contact of the electrosorption carbon material with the aqueous solution in flow mode while feeding the solution at a rate of 10-20 ml per minute per square centimetre of the electrosorption carbon material. Concentration of the extracted metal in the solution is measured and the reduction process is repeated many times. |
 Method of processing oxidised nickel ore / 2381285Invention relates to chemical engineering of inorganic substances and can be used in cases when there is need to produce a nickel concentrate. The method of processing oxidised nickel ore involves mixing the ore with ammonium chloride, heating the obtained mixture and water leaching to obtain a solution. The ammonium chloride is mixed with the material in ratio of 100-150 mol % of the stoichiometric quantity. The mixture is then heated to temperature 200-315°C and kept at that temperature until release of ammonia, water and hydrogen chloride stops. After water leaching, ammonia water is used to precipitate iron and aluminium at pH 6, nickel and cobalt at pH 8-8.5 and manganese, magnesium and calcium at pH above 8.5. |
 Method for production of highly pure tungsten for spattering targets and device for its realisation / 2375480Invention is related to production of highly pure tungsten for spattering targets. Method includes cleaning of ammonium paratungstate from admixtures by ammonia sulfide and further treatment of solution anion-exchange resin AM-p. Then thermal decomposition of ammonium paratungstate is executed at the temperature of 600-800°C to produce tungsten trioxide, as well as cleaning of tungsten trioxide by zone sublimation at the temperature of 900-950°C in continuous flow of oxygen. After sublimation, heterogeneous recovery of tungsten trioxide is carried out by hydrogen at the temperature of 700-750°C to produce tungsten powder, as well as tungsten powder pressing to produce bar. Then electronic vacuum zone recrystallisation of bar is carried out to produce crystals of highly pure tungsten, as well as electronic vacuum melting in flat crystalliser with melting of flat bar from each side to the whole depth at least twice. Device is also suggested for zonal sublimation of tungsten trioxide. |
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Method for obtaining dephosphorised concentrate of oolitic iron ores / 2449031 Invention refers to preparation of iron-ore raw material for metallurgical treatment by cleaning the latter from harmful impurities deteriorating the quality of obtained metals and alloys. Method for obtaining dephosphorised concentrate of oolitic iron ores involves high temperature treatment, cooling and leaching of concentrate with mineral acid. High temperature treatment of iron-bearing material is performed in the range of 1350-1450°C in reducing medium with participation of clinker minerals till molten metal and sinters are formed. They are cooled to magnetising roasting temperature of 750-860°C, crushed and separated with magnetic separation into clinker and concentrate. Then, concentrate is cooled to 50-90°C and supplied at that temperature for leaching with mineral acid for dilution of phosphorus. |
FIELD: process engineering.
SUBSTANCE: invention relates to processing natural uranium chemical concentrate. Proposed method comprises concentrate leaching by nitric acid solution to obtain suspension, adding coagulant into suspension and suspension separation. Clarified solution is separated from residue and directed to extraction. Note here that polyacrylamide-based anion coagulant is used and suspension with said coagulant is subjected to permanent magnetic field effects. Coagulant concentration and duration of magnetic field effects are selected to ensure concentration of insoluble residue now exceeding 100 mg/l in clarified solution. In extraction from clarified solution, no antifloating emulsions are observed.
EFFECT: solution suitable for further extraction.
3 cl, 2 tbl
The invention relates to methods for processing chemical concentrates of uranium, which include the separation of the insoluble residue from solutions of uranyl nitrate (separation of suspensions) refining and extraction using tributyl phosphate (TBP) in a hydrocarbon diluent.
At dissolution (leaching) of chemical concentrates, natural uranium (NUC) formed in solutions of uranyl nitrate are insoluble residues (BUT), composed of hydrated oxides of iron, aluminum and other metals. In the process of extraction refining of uranyl nitrate BUT contribute to the formation of nerasseivayushchee emulsions (jellyfish) of the aqueous phase with the extractant - 30%TBP in a hydrocarbon diluent, which leads to disruption of the extraction process.
If extraction production is focused on the processing of solutions that do not contain a solid phase, insoluble residues should be removed from solutions. But often the leaching NUC form of a suspension, in which the insoluble residues form truefilter suspension, such suspension is difficult to divide into clarified water and residue.
In the method of processing of concentrated natural uranium oxides (RF Patent No. 2323883, IPC 01G 43/01(2006/01), publ. 10.05.2008) insoluble residues is separated from the solution of uranium filter the Oia or centrifugation after leaching in several stages, comprising preparing a concentrated solution of uranium (≈700 g/l) and dilute it in hot (which is unsafe) a weak solution of nitric acid.
A method of refining NUC leaching solution of nitric acid and separating the resulting slurry into solid and liquid components [Kozyrev, A.S., Sikerei YEAR, Ryabov A.S., Shamin, V.I., Mikhailov, N.A., Skuratov MV intensification of the processes of separation of highly concentrated solutions of uranyl and fine suspended solids. Bulletin of the Tomsk Polytechnic University. - 2007. - T. No. 3. - Page 16-19]. The method includes the introduction in the nitric acid solution of uranyl nitrate with a concentration of uranium 300-450 g/l of nitric acid 0.7 to 3.0 mol/l of coagulant cationic type brand FLOQULAT FL 45 in the amount of 100-200 mg/L. Then, the suspension is injected cationic flocculant brand FO 4140 in the amount of 1-10 mg/l After injection of coagulant and flocculant insoluble residues were separated from solution by filtration, got transparent solutions of uranyl nitrate, suitable for the extraction process. The method chosen for the prototype.
Continued research on the selection of coagulants and other methods of separation of suspensions, obtained by leaching NUC. Studies have shown that the content of the suspensions BUT in the uranyl nitrate solution should not exceed 100 mg/l - maximum is the amount of content, wherein in the extraction step is not observed education nerasseivayushchee emulsions.
The objective of the invention is the provision of separation of uranyl nitrate solution from the insoluble residue NUC with obtaining solution suitable for extraction.
The set task is solved by the fact that in the method for processing chemical concentrate of natural uranium, including the leaching solution of nitric acid to obtain a suspension, an introduction to the suspension of the coagulant, the separation of the suspension, separating the clarified solution from the residue and the direction of the solution on the extraction, the suspension is injected anionic coagulant based on polyacrylamide and suspension with coagulant effect of constant magnetic field, the concentration of coagulant and duration of the magnetic field is chosen from the condition of security in the clarified solution concentration of insoluble residues of not more than 100 mg/L.
The coagulant, which represents an anionic copolymer of acrylamide and sodium acrylate with a molecular mass of 12·106injected into the suspension to a concentration of 20-100 mg/L.
Suspension create a constant magnetic field with a strength of not less than 730 kA/m
The method is as follows.
In the method used anionic coagulant based on polyacrylamide coagulant (flocculant) FLOPAM brand'AN 923 PWG, p is establishe an anionic copolymer of acrylamide and sodium acrylate with a molecular mass of 12·10 6.
The suspension obtained from dissolution NUC in a solution of nitric acid, BUT contains - compounds of iron, aluminum and other metals. The suspension is injected anionic coagulant in a specified amount and affect the suspension with coagulant permanent magnetic field. Non-ionic and cationic coagulants have been ineffective (increase efficiency from combining the action of the coagulant and the magnet has not occurred).
Processed NUC with high content of iron and aluminium, close to the limit values given in ASTM C 967-02 for uranium ore concentrate. The initial suspension of uranyl nitrate was prepared by dissolving NUC in a solution of nitric acid. The concentration of uranyl nitrate in the resulting suspensions in terms of uranium ranged (203,1-KZT 205.7) g/l, the concentration of free nitric acid in the interval (104,1-112,5) g/l, iron 30-33 g/l, aluminum 15-16 g/L. HO was about 0.5% of the solution volume.
Conducted two series of experiments:
in the first series of the influence on the clarification of the suspension of the coagulant and the magnet and the length of their impact on the suspension;
in the second series selected the optimum concentration of coagulant.
Held the first of a series of 4 experiments.
In experiment 1 investigated the separation of suspensions in the process of its sludge. Immediately after the dissolution NUC received the ing the suspension was divided into six equal portions of 50 ml each. Then immediately after separation (i.e., without exposure of the suspension) and at set time intervals (5, 10, 15, 20 and 25 minutes of exposure) of each glass were selected from the top 25 ml of suspension, the sample was mixed and measured the optical density of the sample fotoelektrokalorimetry.
In experiment 2 investigated the separation of the suspension after injecting coagulant. Received from dissolution NUC suspension, divided into six portions, added an anionic coagulant type brand AN-923 to its concentration in suspension 40 mg/L. Then spent measuring the optical density of six samples obtained slurry immediately after the introduction of the coagulant and at set time intervals (5, 10, 15, 20 and 25 minutes), selecting from each glass on top of 25 ml of suspension, mixing it and measuring the optical density of the sample fotoelektrokalorimetry.
In experiment 3 investigated the separation of suspensions under the influence of a permanent magnet. Six servings suspension was affected by high-energy permanent magnets Nd-Fe-B, creating a magnetic field in a suspension of not less than 730 kA/m (magnets were installed under the bottom of the glass jars, which were portions of the suspension). At set time intervals (5, 10, 15, 20 and 25 minutes) from each glass top samples were taken suspension and measured their optical density.
In experiment 4 investigated the separation of suspensions under the jurisdiction of coagulant and the impact of a permanent magnet. To do this in six servings of suspension introduced the anionic coagulant type brand AN-923 to its concentration in suspension 40 mg/l and then conducted operations as in experiment 3.
Table 1 shows the results of measuring the optical density of the samples to characterize the degree of clarification of the suspension, depending on the time of exposure to the coagulant and the magnet on the suspension (on the duration of exposure of the suspension to the measurements).
| Table 1 | ||||
| The sample number | The duration of exposure of the suspension, min | The optical density of the sample | ||
| Experience 1 | Experience 2 | Experience 3 | Experience 4 | |
| 1 | 0 | 0,87 | 0,86 | 0,89 | 0,87 |
| 2 | 5 | 0,85 | 0,83 | 0,71 | 0,49 |
| 3 | 10 | 0,83 | 070 | 0,56 | 0,22 |
| 4 | 15 | 0,80 | 0,59 | 0,43 | 0,15 |
| 5 | 20 | 0,74 | 0,48 | 0,34 | 0,13 |
| 6 | 25 | 0,72 | 0,35 | 0,28 | 0,11 |
As can be seen from table 1, when exposed to a suspension of coagulant and magnet depending on the time of exposure to the clarification of the suspension occurs in 2-4 times more efficiently compared with the impact of only one of the coagulant and 1.5-3 times in comparison with the impact of only one magnet.
In the second series of experiments after complete dissolution NUC obtained suspension was divided into several equal portions, in which the coagulant is introduced to concentrations respectively 20, 40, 60, 100, 200, 500 mg/l At all the portions affected by the magnet, as in experiments 3 and 4 of the first series.
The results of the experiments of the second series are shown in table 2.
The concentration of insoluble residue 100 mg/sootwetstwuet optical density clarified solution of 0.18.
As can be seen from table 2, specification clarification suspension (optical density of 0.18, corresponding acceptable for extraction concentration BUT equal to 100 mg/l) when introduced into the suspension of the coagulant and the impact on the suspension of the permanent magnet Nd-Fe-B, creating a magnetic field 730 kA/m, occurs when the concentration of the coagulant 20 mg/l and reaction time 25 min Increase in the concentration of coagulant to 100 mg/l reduces the duration of clarification of the suspension to a predetermined value to 7.5 minutes. Further increase in the concentration of the coagulant suspension does not lead to a significant acceleration of clarification suspension.
After separation of the suspension into clarified water and a residue, the residue was separated from the solution by filtration. The solution is sent to extraction. When the extraction was not observed education nerasseivayushchee emulsions.
1. Method for processing chemical concentrate of natural uranium, including the leaching solution of nitric acid to obtain a suspension, an introduction to the suspension of the coagulant, the separation of the suspension, separating the clarified solution from the residue and the direction of the solution on the extraction, characterized in that the suspension is injected anionic coagulant based on polyacrylamide and suspension with coagulant effect of constant magnetic field, when this end is the filtration coagulant and duration of the magnetic field is chosen from the condition of security in the clarified solution concentration of insoluble residues of not more than 100 mg/L.
2. The method according to claim 1, characterized in that the coagulant, which represents an anionic copolymer of acrylamide and sodium acrylate with a molecular mass of 12·106injected into the suspension to a concentration of 20-100 mg/L.
3. The method according to claim 1, characterized in that the suspension creates a magnetic field of not less than 730 kA/m