JPS5855030A - Separation of isotope - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The subject of the invention is a method for separating isotopes in the form of a two-phase system, for example solid phase-liquid phase, liquid phase-liquid phase, solid phase-gas phase, comprising:
The distribution of isotopes into each phase can be controlled by selection of the phase composition, that is, its structural and material properties,6 and by selection of isotope and ligand concentrations, temperature,
By selecting light irradiation, fluid-mechanical/yarameter,
and based on the knowledge that the phase can be controlled by selection of the length of time that the phases are allowed to contact (for example, uranium, lithium, and It is possible to separate with high efficiency from aqueous solutions (and if necessary from gaseous mixtures thereof) by the method according to the invention in contact with solid absorbents or liquid extractants.Principle This is a problem with chemical separation methods.
-・・Chemical methods of isotope separation that are used to expose and use falsification (2 e.g. Laakorlm B, N, and
@aw, .

Bi-peehl Kklmll e baIIId
XLIV, A5.761 = 7'al11975"
, Caream d@J, and l0IF
・sR@port AAgC/LIB/III! l-
273, 1970), based on isotope exchange reactions), whose equilibrium constant (i.e., usually the element separation factor)
is about 1.0001 to
It varies in the range 1.01, the lower value being related to the isotope of the heavy element (eg uranium). Recently, much attention has been paid to separating uranium isotopes using solid absorbents and liquid extractants. In other words, West German patents and patent applications (e.g. 0082235603゜197
31: 008284951) S, 1973:
DO82623891, 1977), French painting patents (e.g. No. 1@00437, 11NiJI), and Romanian publications (e.g. P@mtam, *Ca
lusarwA,, Is*t@p@nprax1m
13 * AS e214-216 +1
977; 5bld 11, A12.
422-426゜1975).

Efforts to secure a condition for isotope exchange processes of the form % Formula % (in which the Roman numerals (1,1) represent the phase) are common to all O published methods. It is a characteristic.

Nevertheless, uranium (Vl ) Early work toward isotopic fractions was not successful. This explains why uranium exists in various valence states [i.e. UGV) ~ U (Vl) and UO [
) ~ tr (N) ) This is the reason why attention has been paid to the system that exists. In these systems, electron exchange reactions occur simultaneously, and the reactions always enrich lighter isotopes due to the higher valence states of uranium. Furthermore, in connection with complexation reactions and isotopic effects by using a suitable type of absorbent (and if necessary extractant) selective for one of the valence states of uranium, substantially Increased separation efficiency has been achieved in practice/published data (e.g. M,
8@koe T, Mlyake, K, Inad
ae Nuel.

TI@hnolog750, 178-186.198
0 year; R@port INFICC/DICP/WQ
2/31, On theTh@@kml@al
, K@onom supervisor @al and 8af*B
ardInformations of th@
D1ff*rFist InrlehomntTke*
km1quts, March 1s, 1979), it is clear that we succeeded in shifting the value of the element separation factor to about 1.001, which is said to be the lower limit of the economic use of this process. The element separation coefficient of gas diffusion processing, which is used as an operational standard for body separation, is approximately 1.00.
It is 27. Therefore, the obtained results can already be said to be economically and technically advantageous. Nevertheless, operational utilization is not obvious, mainly due to the limited value of the element separation factor, which requires a large number of stages and a large amount of enriched uranium.

! , and necessitating the construction of equipment with a relatively long time required to reach a steady state of the process. The necessity of repeating the redox treatment of uranium many times is associated with the substantial extraneous requirements of the redox agent involved (and, if necessary, the energy of the reaction as well).

These defects are removed by a new method for separating isotopes according to the present invention, which is based on a method of controlled partitioning that takes advantage of isotope effects on concentration in a two-phase system. The second phase is an aqueous or non-aqueous solution of the isotope and ligand at a concentration from 10"M to saturation, or a gaseous mixture of the isotopic components or a gaseous mixture of the isotope and an inert gas. and the isotopes to be separated are in the starting mixture (or solution if necessary) in a molar ratio of 1.10 to 1.100; the second phase is Solid absorbents or mycelium-based bioabsorbents and cellulose-based absorbents (if necessary, such as tarane, silica gel and cellulose)
The above two-phase system can be used for sorption and/or desorption of KtIP (extraction and/or re-extraction if necessary). ) nonlinear isothermal equilibrium (eq
and by complexation of isotopes such as carbonate, sulfate, titanate, chloride and ethylenediaminetetraacetate; By using absorbents and extractants with chelating functional groups such as syl and hydroxyl groups and groups based on phosphorous, nitrogen and sulfur, and/or in the dark or at 25 minutes. Furthermore, under light with a wavelength of am, the contact time of both phases was 1O-2 to 10' seconds, the temperature was 102 to 10'i[, and the rotational speed of stirring was 10
-2 to 10' revolutions per second, reduce the flow rate in the column apparatus to 1
04 to 10-' m/s, and the particle size of the absorbent to 10
-'~l O-'mK and also for desorption or re-extraction of isotopic components, compounds such as sodium carbonate, ammonium nitrate, sodium chloride, sodium sulfate, sulfuric acid, nitric acid and hydrochloric acid; Solutions of compounds containing complexing ligands such as titanate ions, ethylenediacenetetraacetic acid ions, and isobutyrate ions, either alone or from 10''M to saturated solutions II! When used as a mixture of chain degrees and the two phases are brought into contact, the rates of isotope transfer from the -phase to the other phase are unequal and the suppression of isotope exchange (r@tar4a
tiom) occurs; that is what makes it happen.

In the method according to the invention, 2s5. Q/D and i!
To in an aqueous solution of isotopic components such as 38UCVo and ligands such as nitrate, sulfate and carbonate ions.
-), the total concentration of which is 10~1CM, and the dissolved isotopes 2s''U and 2311U in the starting mixture have a peak ratio of 1:!500~1:too,
For example, it is possible to use Ion exchange agent or P based on styrene-divinylbenzene copolymer.

Ckrysegemma* 14 () Lower 1IVIL
It is possible to use absorbents based on mycelium as solid absorbents. In the dark KTh%A or 250-650
The operation was carried out under light with a wavelength of 1 G-' to 1 G-', and the stirring rotational speed was 0.800 to 12.00 revolutions per second, and the flow rate in the column was 10 to 10 m/m.
Using a solid absorbent with a particle size of 'm, the temperature was 273-37
3, and the length of phase contact time is 10"~1G'
can be selected in seconds. 10 ~1. ! Solutions of sodium chloride, sodium decacarbonate, or hydrochloric acid, with a concentration of iMO, can be used for desorption.

The process according to the invention is characterized by a substantially higher separation factor than previously achieved in isotope exchange reactions.

The maximum value of the element separation factor varies between 1.02 and 1.10 in the process of sorption (and also desorption, if desired) of uranium isotopes. Uranium (Vl) solution as well as sorption f! Economic and technical aspects of the isotope separation process according to the invention, where it is particularly advantageous to use a solid absorbent with a high selectivity of fi (then de-passing & if necessary), but with a reaction rate that is not too fast. The overlapping characteristics are considerable. It shows a substantially increased elemental separation factor value, i.e., 1- for the uranium isotope fraction i.
Hexavalent uranium shows a reduction in the number of separation lines at an OI of 1.5, a hold door for enriched uranium in the device on roughly the same order of magnitude, a reduction in the time required to achieve stable conditions, and It is possible to operate with a solution of uranium, without changing its valency, and there is no need to convert it to uranium, UiF4, before enrichment, as is the case in conventional operationally employed nine enrichment steps. Another important point is that the depleted uranium generated by this method can be used as input U material! b) In fact, the content of U isotopes in this waste is reduced by half.

The new method of isotope separation (i.e. in the example of sorption) can be further explained as follows: (a) An aqueous solution of the isotope, e.g. 255 U (y
l)+2! When a solid absorbent or liquid extractant is brought into contact with a static solution in which the concentration of one isotope is at least 0.5 to 1 order of magnitude higher than that of the other, the concentration of both isotopes is Even though sorption occurs simultaneously, the rate of sorption of each isotope is proportional to the driving forces of this process, ie, the relative deviation from equilibrium and the value of the mass transfer coefficient. The generally different rates of sorption of isotopic components, often associated with isotopic exchange (see (g) below), are the nature of an effect called the isotopic effect on concentration. The sorption rate can be expressed, for example, by the relation: % [where R represents the rate of sorption (and desorption, if necessary) of each isotope transfer from one phase to the other, K, . is the mass transfer coefficient, and Δ1. Δ.

represent the driving forces of the process, the respective 1IIIL gradients in the phases @q' and '''C.].

(b) The driving force for isotope transfer from one phase (here the aqueous phase) to the other is a function of the initial concentration of the isotope in both phases, on the one hand, and the change in isotope concentration, on the other hand. (
This change occurs during the process of sorption) isothermal equilibrium in the region of
Depends on the shape of.

(e) Corresponding isothermal equilibration, preferably for a single isotope, in the region of change in intensity, related to the isotope concentration in solution and the manner in which the sorption process is limited.
It is advantageous to select a sorbent which exhibits as much as possible a gradient in the fraction of lmm 1sO4h@rm).

Isothermal equilibrium sorption (equll) corresponding to low concentrations of isotopes
lbrlmm morptlon 1soth@rm)
It appears to be advantageous for the part of 10 to have a slope of about 102-10s and the part corresponding to the high concentration of isotope to have a slope of about 10.

(d) The choice of absorbent is limited by the properties of the absorbent alone, so it is likewise possible to adjust the composition of the solution to the properties of the solvent. In this sense, the isotope ratios are kept at their initial values and the absolute concentration of the isotopes can be adjusted, for example by dilution or even by adjusting the solution composition by adding further components, including complexing agents. Take changes into account.

(・) The mass transfer coefficient is a function of the solution composition (isotope concentration) and the type of absorbent (extractant, if necessary) on the one hand, and on the other hand it is a function of the temperature and hydrodynamic meter, stirring, etc. It is a function of velocity, flow rate, absorbent particle size, etc.;
Since concentration dependence is one of the most important, these mass transfer coefficients generally have different values for each isotope, but their absolute value depends primarily on the type of absorbent. We have found it advantageous to operate with a collection agent whose transfer coefficient is 10 -10 per second.

(f) For example, prescribed bioresorptive agents (Children's Inventor Certificate No. 155833 and Czech Republic Inventor Certificate No. 155833 and Chez;
6) In addition, ion exchangers based on styrene-divinylbenzene copolymers, alone or supported on carriers such as Teflon, cellulose, silica gel, etc., are used as absorbents with the above-mentioned equilibrium and kinetic properties. Is possible.

- Simultaneously with the sorption (and if necessary extraction) of the isotope, an isotope exchange begins to take place practically immediately, and this isotope exchange results in a change in the amount of sorption of a single isotope resulting from different sorption rates. Suppress differences. The negative effects of the isotope exchange process (the rate of which is approximately equal to the sorption rate of isotopes at high concentrations) can be suppressed on the one hand by the selection of the sorbent type and the solution composition. Compensation can be made on the one hand by extensive selection and on the other hand by operating at low temperatures and limited light irradiation. Interfering with isotope exchange is one @
This can also be achieved by complexing the isotopic components in the solution [6], either by adding suitable ligands to the solution or by adding sorbents with complexing functional groups (as required). If it is, it means either by using an extractant) or by using an extractant.

(h) The same statements made above by way of example regarding isotope sorption rates are also in principle true regarding the rates of desorption (and re-extraction if desired) and the rates associated with isotope exchange.

The following margins are activated with hydrated titanium oxide (IL), swelled and based on an absorbent >21, which makes the light impermeable to 293KO.
While mixing at al1m at stirring speed [S rotations per second, -3
, 5 to 11111L90, OIMO uranyl nitrate solution i [
"'U" in initial melt 111 in contact with 60m:
""UllI topic ratio 0.725 x 10""
In the process of sorption reaction, a liquid phase O sample was taken out, and the total concentration of uranium in the sample was measured using the reagent arssna.
Measured by spectroscopic analysis using mol U: 2!1
8U isotope ratio Muld@rmaston -Ml Ir
Measurement was performed using an Omass mod*13Q mass spectrometer.

Based on the obtained results, calculate the value of the separation factor as a function of time and calculate the value of the separation factor as a function of time.
2JXlO' Total uranium personnel storage vehicle O sword 1 G, 0
G6 0.0053 01)046 Separation factor 1
．． 000 0.997 0.976 0.9933
．． 6X10'7.2X10'14.4X10'000
42 0.0037. 0.00351.024 1
．． 630 1.005 separation factor in absorbent! 1
5U:238U isotope ratio o, q-1, same! Defined as the ratio to the body ratio. Why don't you do the experiment under daylight? Example 1 except that We carried out the same process as before and measured the time curve of the total run and isotope ratio in the liquid phase.Based on the obtained results, we calculated the separation stress and O time 4 dependence and calculated the time ( seconds)
0 0JXIG31.2X10" 2.4X10
”Separation coefficient 1,000 0.980 0.98
0 0.9973.6XIG" 7.2X10314
,4X10”0.0042 DJ)039 0.0
0371.01@1.02G 1.025Example 3 The same treatment as in Example 1 was carried out, except that a strongly acidic cation exchanger with the trademark Amb@rllt@IB-120 was used, and the liquid We measured the temporal changes in total uranium astringency and isotope ratio in the phase. From the obtained results, we calculated the time dependence of the separation coefficient.Less than 2 Margin time (seconds) 0 03X10s O,6
X10' separation coefficient 1.000 0.997
1.0251.8X10'3.6XIO' l
0JXIG30.0003 QOOO20,0021
,00? 1.00G 1.001j Euran 4X10 saturated with uranium to a volume of M/I, swollen and centrifuged round, trademark Qstmorb MY 6
5, IM-NI of absorbent #15 was stirred at a temperature of 293 K under light irradiation at a stirring speed of 5 revolutions per second.
Ct+ 0- Z M -Solution of Na2COs 2011
I made contact with 1*! The absorbent O and 2 phase ratio at the beginning of 11k was 0.725XIC. During the course of the sorption operation, a liquid phase sample was taken out, and the total uranium concentration and 2"U:2Isag isotope ratio therein were measured.

The time dependence of the separation factor was calculated from the results: Time @)
O0JXIO30,9XlOs Separation Section $
1.000 0.984 1.0331.8
X1G"3.6X10'l0JXIO'4.
3X1G""4jX1ff"!L2X10""
51.04!5 1.0! ! 6 1.031
Example 5 The same treatment as in Example 4 was carried out with the exception that the experiment was carried out without light irradiation and the total uranium in the liquid phase
l! The time dependence of the zero separation coefficient was obtained by measuring the time change of the isotope ratio and calculated from the results.

Time (seconds) 0 0JXIO' 0.
9XlO' separation coefficient 1.000 1.0511
1.0384.4X10"" 4.1lX10
"-'■ H-decade, swollen and centrifuged, trademark 0stso
rb MV615 absorbent (P, @hrysog@m
um@41101 mycelium-based absorbent) 21 was heated under daylight irradiation at a temperature of 293 K with stirring at a rotational speed of 5 revolutions per second. OIMO uranyl nitrate solution 5011
I was brought into contact with 1. U in starting solution: 2jSIU
The isotope ratio was 0.7!5XIO, which was 6. After 3 hours the two phases were separated and in a second step the solution was brought into contact again with fresh, same absorbent 2I for 3 hours. Overall 4
To carry out these sorption steps, ars@naso
The total uranium concentration in the liquid phase was determined after each step by spectrometry using the I reagent and
-The 255U:21S11U isotope ratio in the absorbent phase was measured in the final stage O1l using a Mlar@mass mod@130 mass spectrometer.From the results, the element separation coefficient of one stage was calculated.The result was 1. It was .020.

The separation factor is defined as the ratio of the 2315g:238U isotope ratio in the absorbent to the same isotope ratio in the liquid phase - in our example, after 3 hours of contact of the phases.

Trademark 0atssrd activated with titanium(IV) oxide
The same procedure as in Example 1 was carried out to carry out the sorption step of 4Il, except that an absorbent named MY615 was used.
The one-stage element separation coefficient was calculated from the results.

1.025 was obtained.

Example 8 Absorbent 5# of 0stsord MY s/s was mixed with 1M -NaCL + O, Z M -H under daylight irradiation at a temperature of 293KK and with stirring at a rotational speed of 5 revolutions per second.
Contact with a solution 20d of a zcOs, and place the absorbent K at the beginning of the experiment at the position 1t ”'U:
After one hour the two phases were separated and a fresh solution of the above composition was added to the absorbent. A total of four such desorption steps were carried out. The total uranium concentration of the solution was measured after each step and the isotope ratio in the absorbent phase was 235g:25.
BU was measured after the final stage.

A single-stage element separation factor was calculated from the results.

1,150 were fired.

Example 9 The same procedure as in Example 3 was carried out except that 0.1M sodium sulfate flIiIl was used for desorption, and 4
The desorption stage was carried out twice. A single-stage element separation factor was calculated from the results.

The same procedure as in Example 3 was carried out, except that a 0.1 M salt solution was used for desorption, and four desorption stages were carried out. carried out. The 7-stage 1M elementary separation coefficient was calculated from the results.

　　.

., 980 were obtained.

Example 11 9.1M tri-n-octerazun solution in base form 2
While stirring 0.0m with a laboratory shaker at a temperature of g2f13K, 0.01M-TJo, 804+01M-N
a21!04. was brought into contact with 100.0 m of a solution of Departure #i [(DM position jt "'U!""Ua O,
725
A batch of uranium is measured by spectroscopy using s+o I, and then Mlltrmastem-Ml@r*a
The isotope ratio was fixed using an IAAS 11m dnL3G mass spectrometer. From the results, we calculated the value of the separation coefficient as the relationship of the patent application.

-Margin time (seconds) OIs 3060 12
0 2400 0.0063 α0071 0.0071 The principle of the partitioning method that controls, more generally, is for components that either have different concentrations or different migration speeds in multiple correlations, i.e., the sorption ( If necessary, it is possible to use desorption for a component if the desorption rate is different for one component. In addition to mixtures of isotopes, rare earths,
Also relevant are substances with similar 4I properties such as KaZrwHf, 22'RawIlm, and the like.

Preparation of pure substances for semiconductors, nuclear reactions and analytical M*
Similarly, with this method, it is possible to use a practical machine with an advantage of 0.6゛°.
1) Haruki Tono 1, Indication of the case 1982 Patent Order No. 145662 2, Name of the invention Method for separating isotopes 3, Relationship with the case of the person making the amendment Patent applicant name: Cheske Bisoke Uryu Te9 = Keku Pra (4. Agent 5, "Detailed description of the invention" column 6 of the specification subject to the amendment, Contents of the amendment ( 1) Statement on page 14, line S and 6 of the specification: “Isothermal equilibrium in region C of concentration change (this change occurs during the sorption process) (*q11111bri11m 1aot
Graph the monotope concentration in the sorbent with the isotope concentration 1:H in the solution. The curve shown. Same hereafter) 1: Correct.

(2) “Isothermal equilibrium (@quilibrlum l5oth@
Correct the part of rm 1 to the equilibrium curve j.

(Statement on page 14, lines 13 and 14 of the 31 Specification: “Sothermal equilibrium sorption corresponding to low concentration isotopes (@quillb
rium 1orbtion 1soth@rm)
is corrected to ``corresponding to the isotope of low variation in the equilibrium curve of r sorption''.

(4) Statement on lines 17 and 18 of the statement llll5 purchase “・
...No. and No...." as r No. 18447
No. 1 and No. 111189198 No. 1: Correction.

Claims (1)

[Claims]! In a controlled isotope separation method using isotopic effects of member changes in a two-phase system, the first phase consists of a ligand having a linear layer of 10 M or more and an aqueous or non-aqueous solution of the isotope, or a gaseous mixture of the isotopic components or a gaseous mixture of the isotope and an inert gas, and the isotopes to be separated are in the starting solution or mixture from 1:i0' to 6 in a molar ratio of 1:10-'; the second phase is a solid absorbent such as a stilpene ion exchanger or a low grade thread-based bioabsorbent and a cellulose-based absorbent. or extractants such as trinotyl phosphate and trioctylamine, either alone or supported on carriers such as Teflon, silica dal and cellulose; l1lIII form 0 isothermal equilibration (sqwllll*rI11alllastk@rsm) in Ku for Hiro extraction and/or re-extraction
can be shown by complexation with ligands such as acetic acid ion O, or by complexation with ligands such as acetate ion O, or by complexation with complexes based on xyl groups, hydroxyl groups, and phosphorous, silica, and sulfur (such as aO). By using a collecting agent and an extracting agent having a functional group, and (
Also #i) Dark place or ti! S X 1G"～1G'
Under light with a wavelength of ms, the long contact time of both phases @
f; 10-" ~ 1G' seconds K, I1 degrees tlG" ~ 10
"ICIC. The stirring speed was selected to be 10 to 10 rotations per second, the flow rate in the column device was 1 to 10", and the particle size of the absorbent was selected to be 10 to 1 G. For addition or re-extraction, compounds such as sodium carbonate, sodium sulfate, nitric acid and hydrochloric acid, as well as complex-forming ligands such as titanate ion, ethylenediane-acetate ion, alone or By operating a solution of a compound such as one that is a mixture of a total concentration of 1GM'& saturated concentration, f, the two phases are brought into contact. A method characterized in that the rate of migration to Fi is unusual and suppression of isotope exchange occurs; 2. In the aqueous solution, “5U (V
Dlj'``'[J(Vl)', Ligand, !-
1,' (using ion nitrate, ii acid, ion, and/or carbonate ion, and the total chain degree is 10''ffi ~ 1
0-'M. 3. The isotope marked # to be separated is present in the starting mixture as 1
: 500~1 : 1000% A ratio "t" 6! ,−
The method according to claim 8, No. 1 JJ, using an absorbent based on horn mycelia, or a styrene-zibi-7-hexabenzene copolymer (a strongly acidic ion exchange agent). 6. The method according to claim 1, wherein the phase contact time is selected to be between 10' and 1 G' seconds. 6. The operation is carried out under light with a wavelength of between 250 and 650 m. 7. The method according to claim 8, wherein the operation is carried out at a stirring rate of 10-4 with an agitation speed of 0,SO to 12.0 revolutions per second and an absorbent with a particle size of 10-4 to 10 rm. Process according to claim 1, carried out at a flow rate in the column apparatus of ~10-' m/sec, wherein said operation is carried out at a temperature of 273 to 373 °C. 9. The method according to claim 1, wherein a sodium chloride sodium decacarbonate solution or a hydrochloric acid solution having a concentration of 10-1 to 15M is used for the desorption X-ray re-extraction.