Extractant for extracting metals and method for producing it
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 the field of chemistry of organophosphorus compounds and hydrometallurgy. It concerns a method of extracting - sinergetnoy mixture:
Tris(2-ethylhexyl) phosphate (T-2)
and di(2-ethylhexyl)phosphoric acid (D-2)
in a molar ratio (0.5-1.25):1.0 and how to use it in hydrometallurgy of non-ferrous, rare earth, uranium metal and the processing of spent nuclear fuel.
Known organophosphorus extractants: tributyl phosphate (TBP), (C4H9O)3RO and di(2-ethylhexyl)phosphoric acid (D2EGFK) (D-2), which are widely used in hydrometallurgy [1-3].
The closest analogue to the invention, the essential features, intended to extractant and the method of its production is  SU 480716 (IPC C 01 F 9/08, publ. 03.11.1975), which describes the extractant for the extraction of metals containing di(2-ethylhexyl)phosphoric acid and method for producing an extractant for the extraction of metals containing di(2-ethylhexyl)phosphoric acid is added to the alcohol of phosphorus oxychloride. However, as returned by this method extractant does not contain trialkylphosphine that affects a relatively low capacity for the extracted metal. In addition, the method malotehnologichen.
Nedoschitaetsya also the need for prior individual components TBP and D-2 specific chemical processes, and low distribution coefficient and low capacity to retrieve the element.
The prototype disadvantages are eliminated by the invention.
The technical result of the invention is to develop a single-stage high-tech way of getting sinergetnogo extractant and the increase in the separation factor and capacity on the extracted metal 20-25%. The technical result is achieved in that the extractant for the extraction of metals containing di(2-ethylhexyl)phosphoric acid, further comprises Tris(2-ethylhexyl)phosphate in a ratio of components (0.5-1.25):1 in moles, and what it is used for the extraction of non-ferrous, rare and precious metals and uranium. Also a method of extracting to extract metals containing di(2-ethylhexyl)phosphoric acid, comprising adding to the spirit of phosphorus oxychloride and wherein the 2-ethylhexanol was added phosphorus oxychloride at a ratio (4.5-5.1):2.0, and when the settings defined by the achievement of the complete passage of the reaction, after which the reaction mixture is maintained until complete removal of the formed hydrogen chloride, then to the mixture was added 1 mol of water, maintain the mixture to complete the hydrolysis, the mixture is then washed and the aqueous layer was separated from the organic residue containing di(2-ethylhexyl)phospho is strong acid and Tris(2-ethylhexyl)phosphate, to 2-ethylhexanol was added phosphorus oxychloride at a pressure of 50-70 mm Hg, and temperature (10±5)°C for 1-1 .5 hours; the reaction mixture is maintained at a pressure of 50-70 mm Hg, and temperature (10±5)°C for 2-3 hours; the reaction mixture after aging at the temperature of (10±5)°C is maintained at a temperature of 45-55°C for 2-3 hours; washing the reaction mixture performed with saline reagent.
After washing the reaction mixture 10-20% sodium chloride solution and separation of the aqueous layer in the organic residue, sinergetny extractant (T-2 D-2) in a molar ratio (0.5-1.25):1.0. Output (90-95)%. The finished product containing 1-5% of mono(2-ethylhexyl)phosphoric acid used in the extraction process.
Getting hold of the extractant in the interaction of 2-ethylhexanol with phosphorus oxychloride according to the equation:
A characteristic feature of the synthesis sinergetnogo extractant is that, by adjusting the ratio in moles of 2-ethylhexanol and phosphorus oxychloride, you can get sinergetnuyu mixture of T-2 D-2 different composition in moles(1:1), (1:2), (1:3). This is important in the sense that, for example, extraction separation of Co and Ni, a mixture of 10-30% solution of D-2 and 5% solution of T-2 in kerosene (p.166 ). The extraction of vanadium, a mixture of 6% solution of D-2 and 3% solution of the T-2 in kerosene, separating it from the uranium, iron, molybdenum (page 291 ). Extraction separation of uranium, thorium, rare earths, iron, calcium, aluminium successfully implemented extractant 0.1 M D-2 and 0.1 M TBP in kerosene (str ). Use sinergetnoy mixture of T-2 D-2 in a ratio of 0.1 M in kerosene allows you to achieve similar results.
When comparative experiments on the extraction of used D-2 TBP (analogues), sinergetnuyu mixture of D-2 + TBP (str.257 ) and sinergetnuyu mixture of D-2 + T-2 (the subject matter). Extractant solutions were prepared on lighting kerosene "KO-30" (organic phase).
For the extraction of uranium used a solution of the following composition: H2SO40.1-300 g/l, HNO30-30 g/l, Fe3+0-10 g/l,0.8-30 g/l (aqueous phase). In the course of study is determined by the extraction of uranium and the separation of uranium/iron (III).
The extraction was performed in a countercurrent mode in 6-chamber mixer-settler (volume mixing chamber 0.5 l, sucky camera 2.5 l, the performance by the sum of the phases in all cases was 10.5 l/h). In all cases, the correlation of phases In:0=4:3.
Extraction isotherm were removed using a cross flow. The speed of separation of phases was determined by the rate of release of the aqueous phase after stopping the mixer.
Uranium extraction isotherm shown in the drawing, the concentration ur the a and iron (III) - saturated organic phase, and the speed of the separation are shown in table 1.
|Table 1. Some technological parameters extraction of uranium analogue prototype and (T-2 - D-2 in the ratio 1:1)|
|No.||The extractant||U in the us. PF, g/l||Fe(III) in us. PF, g/l||Koefed. U/Fe||Speed on a budget. mm/min||The third phase, %|
|1||0.14 M D-2||8.6||39||2.0·101||39||UTS.|
|2||0.14 M D-2 + 0.14 M TBP||15.5||0.02||7.1·104||32||UTS.|
|3||0.14 M D-2 + 0.07 M T-2||15.2||3.9||3.6·102||35||UTS.|
|4||0.14 M D-2 + 0.14 M T-2||20.3||0.02||9.4·104||32||UTS.|
As follows from the data of the drawing and table 1, in binary mixtures with D-2 Tris(2-ethylhexyl)phosphate significantly improves the technological characteristics of the sinergetnogo extractant - capacity organic phase uranium increases by 20-30%, the separation factor of U/Fe also increases by 20%, in addition, improves rasslaivanie, the formation of the "third" phase of extraction is not noted in either of these systems.
The methodology and results of experiments on uranium Stripping and getting U2About3.
Uranium from saturated samples of the extractant was extragonadal 10% (NH4)2CO3+ 3% NH4NO3(O:b=3:1, T=35°, τ=1 hour). After Stripping, the phases were separated in a separating funnel, the crystals ammoniyuraniltrikarbonata (AUTKA) was separated from the mother liquor and washed reextracted with a solution, which was pre-saturated with uranyl nitrate to the equilibrium concentration.
The degree of Stripping was calculated by the residual concentration of uranium in the organic phase. For all investigated extractants value of the degree of Stripping was in the range of 99.2-99.6%.
Samples washed AUTKA was progulivali at T=700° (τ=1 hour), the resulting oxide-uranium oxide was analyzed for phosphorus and iron, as these elements are the main limiting impurities in the U3O8- iron in large quantities is always present in industrial product solutions, a source of phosphorus can be themselves and organophosphorus extractants. The results of analyses of samples of nitrous oxide, are presented in table 2.
|Table 2. The content is the W of the main limiting impurities in the nitrous oxide-uranium.|
|Component||Requirements TU||The content in samples|
Thus, the tested extractants provide U3O8the required degree of purity. Tris-2-etilgeksilfosfat on the technological quality is much greater than TBP. Mixed extractant D-2 + T-2 has a capacity of uranium 20-30% more than the D-2+TBP, as well as increased selectivity and recovery. The speed of separation is not worse than in the system with D-2+TBP.
In all cases, the result of Stripping turns oxide-uranium oxide required degree of purity for basic limited type impurities.
Extraction separation of cobalt and Nickel from the sulfuric acid solution was conducted with a mixture sinergetnoy D-2 + TBP = 10-30%: 5% placeholder in kerosene (p.166 ). The source of the sulfuric acid solution had a pH of 5-6. The ratio of Co/Ni in the aqueous phase of 1:1. Extraction was carried out at a temperature of 60°C. Received 95.7% cobalt extraction ratio in the organic phase Co/Ni=17.4. Use sinergetnoy mixture of T-2 D-2=0.5-1.0 moles (or 4% solution of T-2 and 10% solution of D-2) in kerosene was possible to achieve separation of Co/Ni=18.6 when removing cobalt in the organic phase is 96%.
When removing VANADIS iron-foundry sludge production and oil fly ash, uranium-vanadium ores, titanium-iron magnesite produced sulfuric acid solution. As a result of heating them with powdered iron vanadium goes into 4-valent state.
The extraction was carried out in six stages of mixer settler, applying a solution of 6% D 2% and 3% TBP in kerosene (str.291 ) (prototype). Reextraction are 4 stages of a sulfuric acid concentration of 140 g/l at a temperature of 38-50°s Reextract contains 55-65 g/l V2O5. Vanadium is transferred in the form of hexavanadate sodium (red cake)that the ignition is switched to 98% by vanadium.
Using this process sinergetnoy mixture of T-2 - D-2 gives similar results.
Example 1. Synthesis sinergetnogo extractant-2-D-2 (ratio 1:1)
In a 4-necked 0.5 l glass reactor with stirrer, thermometer, addition funnel, barbaterom air passed through the tube with phosphoric anhydride, and fitting for connecting a vacuum load of 150 g of 2-ethylhexanol. The reactor is cooled to a temperature of +5°and under stirring and blowing dry air through the barbaterom under vacuum 50-70 mm Hg for one hour is added 36.6 ml of phosphorus oxychloride. Upon completion of addition, the reaction mixture was kept in the same conditions for 2 hours, then the temperature of the mass was raised to 45-55°and maintained under these conditions for another 2 hours.
After that, the reactor when the temperature is re 45-55° With added 10 ml of water and allowed to stand for 1 hour. The reaction mixture is cooled to a temperature of 20-25°C, add 100 ml of 10% aqueous NaCl solution, stirred and after peeling share. The organic residue was washed with 100 ml of water and separated.
The organic residue 145 g sinergetnoy mixture of Tris(2-geksiletil)phosphate and di(2-ethylhexyl)phosphoric acid.
The output of 95.7%.
Analysis: D-2 - 37.5%, mono-2EGFK - 2.8%, 2-ethylhexanol - 5.2%, Tris-(2-ethylhexyl)phosphate - 54.5%.
Ratio: (T-2 D-2)=(0.11:0.1) g/mol.
Chem. shifts in NMR: T-2 δ31R - 1.200 ppm; D-2 - δ31R - 0.7 ppm; mono-2EGFK δ31P - (-10.79 ppm)
Example 2. Synthesis sinergetnogo extractant-2÷D-2 (ratio 0.5:1).
The synthesis was carried out on the installation, as described in example 1. The ratio of reagents in moles used 2-ethylhexanol:phosphorus oxychloride 4.66:2. The reactor was charged 150 g of 2-ethylhexanol, cool it to a temperature of +5°and under stirring and blowing dry air through the barbaterom, under vacuum 50-70 mm RT. Art. for 1 h was added 45 ml of phosphorus oxychloride. Upon completion of addition, the reaction mixture was kept in the same conditions for 3 h, then the temperature was raised to 45-55°and incubated for another 2 h under these conditions. After that, the reactor at a temperature of 45-55°gradually add 10 ml of water and incubated for 1 h, After cooling to a temperature of 20-25°Reaktsionnuyu the mixture was washed with (2× 50 ml), 10% solution NCl, then (2×50 ml), 5% solution of ammonium bicarbonate and water. After keeping the organic residue in vacuum at a temperature of 60-80°C for 1.5-2 h are sinergetnuyu mixture of T-2 D-2=0.5:1 in moles, exit 162 g (91%).
Analysis: D-2 58.1%, T-2 32%, "-ethylhexanol - 3.2%, mono-2EGFK - 4.7%, 2-etilgeksilhlorid - 1.9%.
Chemical shift31R corresponds to example 1.
Example 3. The extraction of uranium using extractants
Extraction was carried out in 6-chamber extractor, as described above. The solutions were prepared on lighting kerosene "KO-30" (organic phase).
Uranium was extracted from industrial solution of the following composition: U - 15/8 g/l, Fe3+- 1.45 g/l, H2SO4- 125 g/l HNO3- 12 g/l (aqueous phase).
In the course of study is determined by the extraction of uranium and the separation of uranium/iron III.
a) 0.14 M Extractant D2EGFK (similar)
Rich extractant - 8.65 g/l U, 48 mg/l Fe3+the raffinate - 9.3 g/l U. Removing U OF 41.1%, a separation factor of U/Fe=19.8.
b) 0.14 M Extractant D2EGFK + 0.14 M TBP (prototype)
Rich extractant - 15.6 g/l U, 0.04 mg/l Fe3+the raffinate-4.11 g/l U. Removing U OF 74%, a separation factor of U/Fe=35800
in) 0.14 M Extractant D2EGFK + 0.14 M TALL (subject matter).
Rich extractant - 20.6 g/l U, 0.02 mg/l Fe3+the raffinate is 0.34 g/l U. Removing U OF 97.8%, a ratio RA is the fission of U/Fe=94600.
Example 4. Extraction separation of cobalt and Nickel from sulfate solutions was conducted sinergetnoy mixture of D-2:TBP=(10-30)%:4% in kerosene (prototype) in comparison with sinergetnoy mixture of D-2:T-2 (the subject matter).
Original sulfuric acid solution had a pH of 5-6. The ratio of Co/Ni in the aqueous phase of 1:1. Extraction was carried out at a temperature of 60°C. Received 95.7%, cobalt extraction the ratio OF Co/Ni = 17.4.
Use sinergetnoy mixture of D-2:T-2=(0.5:1) in moles (or 10% solution of D-2 and 4% solution of T-2) in kerosene was possible to achieve separation of Co/Ni = 20.6 in OFFICE, when extracting cobalt 96% OF.
Thus, the present invention has several advantages. First, the extractant provides high recovery of metal in PF and a higher separation factor of metals, which is the economic advantage.
Furthermore, the method of extracting a single stage, which simplifies the production process and provides a significant economic effect.
Sources of information
1. Burger L.L., Wagner R. Chem. Engng. Data Series, 3, 2, 310(1958).
2. A.S. USSR 202101, 14.09.1967.
3. "Modern radiochemistry", V.M. Vdovenko M: Atomizdat, 1969, p.106.
4. Coleman C.F., Blake C.A., Brown, K.B., Talanta. 9, 3, 297(1962).
5. "Modern radiochemistry", V.M. Vdovenko M: Atomizdat, 1969, p.116].
6. Gmitc, Averbrook, "Extraction" M: metallurgy, 1983, p. 166, 257, 291, 299.
7. The near the nuke NK, Protasov L.D., Capkova R.S., SU 480716 (IPC C01 F 9/08, publ. 03.11.1975).
1. The extractant for the extraction of metals containing di(2-ethylhexyl)phosphoric acid, characterized in that it further comprises Tris(2-ethylhexyl)phosphate in a ratio of components (0.5-1.25):1.0 in moles.
2. The extractant according to claim 1, characterized in that it is used for the extraction of non-ferrous and rare earth metals and uranium.
3. The method of extracting to extract metals containing di(2-ethylhexyl)phosphoric acid, comprising adding to the spirit of phosphorus oxychloride, wherein the 2-ethylhexanol was added phosphorus oxychloride at a ratio (4.5-5.1):2.0 and parameters defined by the achievement of the complete passage of the reaction, after which the reaction mixture is maintained until complete removal of the formed hydrogen chloride, then to the mixture was added 1 mol of water, maintain the mixture to complete the hydrolysis, the mixture is then washed and the aqueous layer was separated from the organic residue containing di(2-ethylhexyl)phosphoric acid and Tris(2-ethylhexyl) phosphate.
4. The method according to claim 3, wherein the 2-ethylhexanol was added phosphorus oxychloride at a pressure of 50-70 mm Hg, and temperature (10±5)°C for 1-1 .5 hours
5. The method according to claim 4, characterized in that the reaction mixture is maintained at a pressure of 50-70 mm is TST and temperature (10±5)°C for 2-3 hours
6. The method according to claim 5, characterized in that the reaction mixture after aging at the temperature of (10±5)°C is maintained at a temperature (45-55)°C for 2-3 hours
7. The method according to p.p.3-6, characterized in that the washing of the reaction mixture is performed with saline reagent.
FIELD: uranium technologies.
SUBSTANCE: method comprises sorption of uranium on low-basicity anionites, desorption of uranium, and recovery of finished product. In particular, uranium-saturated low-basicity anionite is converted into OH- form and uranium into soluble stable complex [UO2(CO3)3]-4 by treating sorbents with alkali metal and ammonium carbonate solutions.
EFFECT: achieved complete desorption of uranium and simultaneously sorbent is freed from poisons and other sorption components.
FIELD: chemical technology; deactivation and decontamination of radioactive industrial products and/or wastes.
SUBSTANCE: proposed method designed for deactivation and decontamination of radioactive industrial products and/or production wastes incorporating Th-232 and its daughter decay products (Ra-228, Ra-224), as well as rare-earth elements, Fe, Cr, Mn, Al, Ti, Zr, Nb, Ta, Ca, Mg, Na, K, and the like and that ensures high degree of coprecipitation of natural radionuclides of filtrates, confining of radioactive metals, and their conversion to environmentally safe form (non-dusting water-insoluble solid state) includes dissolution of wastes, their treatment with barium chloride, sulfuric acid, and lime milk, and separation of sediment from solution. Lime milk treatment is conducted to pH = 9-10 in the amount of 120-150% of that stoichiometrically required for precipitation of total content of metal oxyhydrate; then pulp is filtered and barium chloride is injected in filtrate in the amount of 0.4 - 1.8 kg of BaCl2 per 1 kg of CaCl2 contained in source solution or in pulp and pre-dissolved in sulfuric acid of chlorine compressors spent 5-20 times in the amount of 0.5 - 2.5 kg of H2SO4 per 1 kg of BaCl2. Then lime milk is added up to pH = 11 - 12 and acid chloride wash effluents of equipment and production floors are alternately introduced in sulfate pulp formed in the process at pulp-to-effluents ratio of 1 : (2-3) to pH = 6.5 - 8.5. Filtrate pulp produced in this way is filtered, decontaminated solution is discharged to sewerage system, sediment of barium and calcium sulfates and iron oxysulfate are mixed up with oxyhydrate sediment formed in source pulp neutralization, inert filler and 0.5 - 2 parts by weight of calcium sulfate are introduced in pasty mixture while continuously stirring them. Compound obtained in the process is placed in molds, held therein at temperature of 20 - 50 oC for 12 - 36 h, and compacted in blocks whose surfaces are treated with water-repelling material.
EFFECT: reduced radioactivity of filtrates upon separation of radioactive cakes.
8 cl, 1 dwg, 1 ex
FIELD: chemical technology; recovery of deactivated and decontaminated radioactive industrial wastes.
SUBSTANCE: proposed method that can be used for deactivating and decontaminating industrial radioactive wastes incorporating Tb-232 and their daughter decay products (Ra-228, Ra-224), as well as rare-earth elements, Fe, Cr, Mn, Sl, Ti, Zr, Nb, Ta, Ca, Mg, Na, K, and the like includes dissolution of wastes, treatment of solutions or pulps with barium chloride, sulfuric acid, and lime milk, and separation of sediment from solution. Lime milk treatment is conducted to pH = 9 - 10 in the amount of 120-150% of total content of metal oxyhydrates stoichiometrically required for precipitation, pulp is filtered, and barium chloride in the amount of 0.4 - 1.8 kg of BaCl2 per 1 kg of CaCl2 contained in source solution or in pulp, as well as pre-diluted sulfuric acid spent 5 - 20 times in chlorine compressors in the amount of 0.5 - 2.5 kg of H2SO4 per 1 kg of BaCl2 are introduced in filtrate. Alternately introduced in sulfate pulp formed in the process are lime milk to pH = 11 - 12, then acid chloride wash effluents from equipment and industrial flats at pulp-to-effluents ratio of 1 : (2 - 3) to pH = 6.5 - 8.5, and pulp obtained is filtered. Decontaminated solution is discharged to sewerage system and sediment of barium and calcium sulfates and iron oxysulfate are mixed up with oxyhydrate sediment formed in source pulp neutralization process; then 35 - 45 mass percent of inert filler, 10 - 20 mass percent of magnesium oxide, and 15 -m 25 mass percent of magnesium chloride are introduced in pasty mixture formed in the process while continuously stirring ingredients. Compound obtained is subjected to heat treatment at temperature of 80 - 120 oC and compressed by applying pressure of 60 to 80 at.
EFFECT: reduced radioactivity of filtrates upon separation of radioactive cakes due to enhanced coprecipitation of natural radionuclides.
7 c, 1 ex
FIELD: rare, dispersed and radioactive metal metallurgy, in particular hydrometallurgy.
SUBSTANCE: invention relates to method for reprocessing of polymetal, multicomponent, thorium-containing radwastes, formed when reprocessing of various mineral, containing rare-earth elements, Nb, Ta, To, V, Zr, Hf, W, U, etc. Method includes treatment of solution and/or slurry with alkaline agent; introducing of sulfate-containing inorganic compound solution and barium chloride; treatment of obtained hydrate-sulfate slurry with iron chloride-containing solution, and separation of radioactive precipitate from solution by filtration. As alkali agent magnesia milk containing 50-200 g/dm2 of MgO is used; treatment is carried out up to pH 8-10; sodium sulfate in amount of 6-9 g Na2SO4/dm2 is introduced as solution of sulfate-containing inorganic compound; barium chloride solution is introduced in slurry in amount of 1.5-3 g BaCl2/dm2. Hydrate-sulfate slurry is treated with solution and/or slurry containing 0.8-16 Fe3+/dm2 (as referred to startingsolution) of iron chloride, followed by treatment with high molecular flocculating agent and holding without agitation for 0.5-2 h. Radioactive precipitate is separated from mother liquor, washed with water in volume ratio of 0.5-2:1; then washed with sodium chloride-containing solution and/or slurry in volume ratio of 0.5-2:1; radioactive precipitate is removed from filter and mixed with mineral oxides in amount of 0.5-0.8 kg MgO to 1 kg of precipitate. Formed pasty composition is fed in forms and/or lingots and presses with simultaneous heating up to 80-1200C.
EFFECT: filtrate with reduced radioactivity due to increased codeposition coefficient of natural Th-232-group radioactive nuclide, in particular Ra-224 and Ra-228, with radioactive precipitates.
10 cl, 1 ex
FIELD: chemical engineering.
SUBSTANCE: method consists in (i) preliminarily reducing laterite particles in reactor, preferably fluidized-bed reactor, to produce in situ reducing gas via addition of reducing, for example carbon material, into fluidized-bed chamber, (ii) fluidizing the bed with oxidizing gas, and (iii) maintained reactor temperature such as to allow partial combustion of coal and formation of reducing medium. Calcined product with carbon level 1.0 to 1.5 is finally discharged from reactor.
EFFECT: enhanced process efficiency.
26 cl, 2 tbl