JPS59220644A - Large scale continuous displacement chromatography method improved in separation characteristic - Google Patents

Abstract

PURPOSE:To enhance separation capacity, by suppressing liquid mixing to a minimum degree by using a high performance liquid separating apparatus for aiming to uniformly disperse a liquid toward the radius direction in a large scale ion exchange tower. CONSTITUTION:In an ion exchange tower constituting the circuit for continuous displacement chromatogaphy, because a flowing condition is not always made constant and a packing layer repeats swelling and shrinkage at a cycle such that a lithium adsorbing zone undergoes one cycle of the circuit, the liquid sump part in the upper part of a resin layer can not be eliminated. The liquid mixing in the axial direction of the liquid sump part in the upper part of the resin layer receives large influece by the structure of the dispersing device attached to the upper part of the ion exchange tower. As the structural example of the liquid dispersing device, there is a perforated plate laminating system wherein three perforated plates are superposed to successively disperse a liquid to the raidus direction thereof or a branch pipe system for dispersing the liquid to the radius direction from the center thereof by utilizing perforated pipes. In the branch pipe system, the number of orifices are reduced to inject the liquid from each orifice provided to the leading end of each branch pipe as a jet stream which is, in turn, impinged to the lid of the ion exchange tower to be converted to a narrow stream and the reverse stirring of the liquid is created in the liquid sump by said narrow stream to increase the dispersibility of the liqud to the radius direction.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a large scale continuous displacement chromatography process with improved separation performance.

Specifically, the present invention is directed to lithium isotope separation using displacement chromatography, and the purpose of dispersing the liquid uniformly in the radial direction in each large ion exchange column constituting a continuous displacement chromatography device is to achieve high efficiency, thereby improving the efficiency of the entire device. The present invention relates to a continuous displacement chromatography method that improves separation performance.

Substitution chromatography VrCJ: A system called the circuit system or merry-go-round system in which multiple ion-exchange resin-packed columns are connected via piping for lithium isotope separation.
Therefore, it can be performed continuously. The lithium adsorption zone is pushed by the displacing agent in this device and moves through the ion exchange column without changing its length, elutes from the bottom end of the column, and connects to the next column all the way to the top of the next column. The process of flowing in from the column, being adsorbed again by the ion exchange resin layer, moving inside the column, being bathed out again from the bottom of the column, and flowing into the next column is repeated.

Lithium isotope separation method using ion-exchange resin uses two naturally stable lithium isotopes, 6Li and 7L.
This method takes advantage of the fact that there is a difference in the adsorption power to ion exchange resins among i. Isotope separation occurs when the lithium adsorption zone moves within the ion exchange resin layer, and an isotope concentration distribution is formed in the axial direction within the column. , 11-way liquid mixing occurs and the effectiveness is reduced. The lithium isotope separation coefficient of the theoretical plate A/R is 7b, which is as small as about 1,003, and in order to perform separation efficiently, it is essential to minimize the loss of separation effect due to liquid mixing. In order to increase the throughput of lithium isotope separation using displacement chromatography f/iLJ, a method of increasing the diameter of the ion exchange column is used, but the flow rate is relatively small for the entire liquid flowing through the exchange column.
Thin pipes are used to minimize liquid mixing in the pipes that connect the pipes.

Therefore, the lithium solution flowing into the thin and thick ion exchange tower is uniformly dispersed in the radial direction inside the column to minimize liquid mixing in the cardinal direction, and the lithium solution is distributed from the bottom of the thick ion exchange column by the thin pipe. In order to completely elute the helithium solution, it is necessary to collect the liquid uniformly in the radial direction of the column so as to minimize liquid mixing in the cardinal direction.

Conventionally, attempts to separate lithium isotopes using fully continuous MD% chromatography have been carried out using small columns with a diameter of about 2 cTηφ, and no special attention has been paid to uniform dispersion of the liquid in the radial direction of the column. do not have.

To disperse the liquid in these small-diameter columns, a filter made entirely of Teflon powder is used in the upper part of the column.

In addition, large ion exchange resin towers are used in high-flow water purification equipment, various useful component recovery equipment, etc.
Regarding the radial liquid dispersion device in the upper part of the column, in the case of an ion exchange column that constitutes the entire circuit for continuous displacement chromatography, which is the object of the present invention, how important is W- in terms of performance? Because of this, dispersion performance has not been carefully studied.

If lithium isotopes are industrially separated by continuous displacement chromatography, it is expected that the diameter of the ion exchange tower that makes up the circuit will be around 150 crnφ. There are 2
In order to perform industrial-scale separation while maintaining the separation performance of a circuit consisting of a cmφ ion exchange column, it is necessary to minimize the total axial liquid mixing that occurs within the continuous displacement chromatography circuit. Yes.The present invention has
A system that achieves the above goals by improving radial liquid dispersion in the upper part of a large ion exchange column and minimizing axial liquid mixing, making it possible to completely separate lithium isotopes by high-performance large-scale continuous displacement chromatography. It is.

As shown in Figure 1, a continuous displacement chromatography circuit for separating lithium isotopes consists of multiple chromatography columns, with automatic control valves installed above and below each column. After the lithium adsorption zone has moved, the column filled with the displacing agent is regenerated and can be reused.
Lithium-absorbing fireflies can travel long distances. The lithium adsorption zone exists across a plurality of columns K and moves from column to column. The ion exchange column for large-scale displacement chromatography is the second one.
The structure is as shown in the figure, and the liquid entering the thin pipe is uniformly dispersed in the radial direction by the liquid distributor at the top of the column, flows uniformly throughout the ion exchange resin-packed column, and is distributed to the bottom of the column. The liquid is uniformly distributed in the pipe before exiting to the piping. During this time, it generally undergoes various axial liquid mixing.

The inventive point is that in an ion exchange tower filled with fine ion exchange resin having a particle size of about 100 μm, as in the case of the target lithium isotope separation, the liquid above the ion exchange resin packed bed out of the liquid mixture is It was devised as a result of the discovery that liquid mixing in the pool area has the greatest effect on separation performance. It is desirable to operate without as much as possible in the liquid pool above the resin layer.
In the case of an ion exchange column that constitutes a circuit for continuous displacement chromatography, the flow conditions are not always constant, but because the packed bed repeatedly swells and contracts every cycle of the lithium adsorption zone through the circuit, the liquid pool above the resin layer is cannot be eliminated. The axial liquid mixing in the liquid pool above the resin layer is greatly influenced by the structure of the liquid disperser that can be accessed at the top of the ion exchange column. As shown in Figure 3, an example of the structure of a liquid disperser is the perforated plate stacking method (FI) in which three perforated plates are stacked and dispersed in the radial direction.
-P 10) Branch pipe method that uses perforated thin tubes to disperse liquid in the radial direction from the center (1) D -H88
, PI)-H20, PD-1-I8), etc.

In order to make the liquid pool at the top of the hatsumode layer as small as possible, the perforated plate lamination method is easier to remove than the branch pipe method. Good. In the case of the branch pipe method, the number of holes is appropriately reduced rather than the number of holes, and the liquid is jetted out as a jet stream from the diameter hole at the tip of the branch pipe, and the liquid is not applied directly to the resin layer surface [i1] but directly to the surface of the ion exchange tower. On the other hand, it is possible to increase the dispersibility in the radial direction by causing complete disturbance of the liquid within the narrowed liquid pool.

[Example 1] A 2 cm φ glass column was constructed in a Zerkind for continuous displacement chromatography as shown in FIG. 1, and the column was completely filled with a strongly acidic cationic father-containing resin Diaion S K 116 (average particle size 100 μIn). Ion exchange resin gold 2N
After making the H-form with hydrochloric acid and thoroughly washing with pure water, a 7 m lithium adsorption zone was formed with an aqueous lithium acetate solution (C!
oNa) to make the adsorption zone in Zarkint 190
When the lithium adsorption zone was completely eluted and the eluate was analyzed, the -j concentration distribution shown in FIG. 4 was obtained.

[Example 2] A large ion exchange column with a column diameter of 50 cm and a length of 1 m shown in FIG. 2 is filled with a strongly acidic cation exchange resin Gui, Ai, Tong 5K116 (average particle size 200 ltm). Make the resin-i H type with a sufficient amount of 2N hydrochloric acid and wash thoroughly with pure water. Separately, a mixed solution of 0.8 mat/L lithium hydroxide (LiOIi) and 0.2 mob/L sodium hydroxide (NaOH) was passed through the tube and the breakthrough curve was measured. As a liquid disperser, PD- in Fig. 3 is used.
FIG. 5 shows the breakthrough curve when H2' O was attached. Figure 5 V? The breakthrough curve obtained in an experiment using a small-diameter glass column with a column diameter of 2 cnrφ under the same flow conditions is also shown.

The slope of the lithium concentration distribution, which indicates the separation performance of the ion exchange column, is Vf:. Almost the same results are obtained in the case of a large ion exchange column with a diameter of 50 cnrφ and in the case of a small diameter glass column with a diameter of 2(:rnφ).

[Brief explanation of the drawing]

Figure 1 shows a system for continuous displacement chromatography, in which 1 is an industrial water storage tank, 2 is an activated carbon column, 3 is a pure water production device,
4 is a lithium bath liquid storage tank, 5 is a hydrochloric acid punishment tank, 6 is a 2N hydrochloric acid storage tank, 7 is a replacement agent adjustment tank, 8 is a replacement agent storage tank, 9 is a pure water storage tank, 10 is a plunger pump, 11 is a medium heat side 12 is a waste liquid storage tank, 13 is a waste liquid neutralization tank, and 14 is a temperature control unit. Figure 2 shows a 50Cn+φ dog-shaped ion exchange tower, where 1 is a liquid disperser, 2 is a liquid collector, 3 is an ion exchange resin layer, and 4 is a liquid droplet. Liquid disperser in Figure 3? Indication 1 1 is a perforated plate lamination method (Ii”D-P 10 ), 2
3 is a branch pipe method (PD-1488), 3 is a branch pipe method (pD-
1-i 20 ), a four-branch pipe system (PD-H8). Figure 4 is a graph showing the lithium isotope concentration distribution,
The horizontal axis is the length of the lithium-N absorption band →, and the left vertical axis is OAK ”L
j mole fraction, right vertical axis (L': 1 'L1 mole fraction all shown, curve is natural isotope mole fraction 0.9258 C"Li
) is shown. Figure 5 is a graph showing a comparison of breakthrough curves.
4#4 Illustration, continuation? IIi Correct; Q' (Spontaneous) 6゜September 12, 1980 Kazuo Wakasugi, Commissioner of the Office of the Secretary of State for Information and Communications 1, Indication of the case 1982 Patent Application No. 094 G No. 2, Title of the invention a11 Performance Large-scale continuous displacement chromatography method improved on 3, and its relationship with the amendments to the study M Go to patent application Address 2-2-2 Uchihamachi, Chiyoda-ku, Tokyo Name (4)
09) Romoto Atomic Energy Research Institute 4, Agent ■104 Address 8-15, Ginza, Chuo-ku, Tokyo Published by IOf)217
F Diamond Heights 4 October amendment details (1) rcH, CooLij on page 7, line 18 of the specification
is corrected to 'CH3COOLi'. (2) Correct rcH3CooNaJ on the last line of page 7 to rcICOON aJ. (3) On page 8, line 8, 0.8 for each Y is changed to 0.2 for each Y.
Correct to ノ. (4) Correct "and 0.2" on page 8, line 9 of the same page to "r and 0.8." (5) Between the 7th and 8th lines of page 9, “A is H!LO, B is HC/!, C is CH3COON
a. D is C) (sC00L, i, E is CHCOOT-(
, F inserts 35% I C6, G inserts 48% Na OHJ. (6) “Curve” on page 9, line 18 of the same page is changed to “J Kyoto J ni 8
1 Correct. (7) On page 9, line 19, "indicate" is corrected to "used something." (8) Correct the drawing Figure 1 as shown in separate ♀L.

Claims (1)

[Claims] In VC for lithium isotope separation using displacement chromatography, liquid flowing into the upper part of a large ion exchange tower completely filled with small particle size ion exchange resin is dispersed in the radial direction inside the tower using a high performance liquid dispersion device. A large-scale continuous displacement chromatography method with improved separation performance that consists of homogeneous dispersion and minimal liquid mixing.