Method for extracting Pb-212 from radium solution

Abstract

The invention discloses a method for extracting Pb-212 from a radium solution, which comprises the following steps: sequentially removing matrix thorium and actinide in a proton irradiation thorium target to obtain a radium crude product solution; the radium crude product liquid passes through a cationic resin column or TK101 resin or TK102 resin, residual impurity elements are removed, and Ra product liquid is obtained; the Ra product liquid is placed for a set time, so that the activity of the daughter Pb-212 of the Ra product liquid meets the requirement; the Ra product liquid is diluted to obtain a diluent, and the concentration of nitric acid in the diluent reaches 0.001-0.01 mol / L; enabling the diluent to pass through a TK100 resin column loaded with a di-tert-butyl dicyclohexyl-18-crown-6 and di (2-ethylhexyl) phosphate extraction agent; the TK100 resin column is washed with nitric acid with the concentration of 0.001-0.01 mol / L, and the washing volume is 2-3 column volumes; and then washing the TK100 resin column by using 5.5 to 6.5 mol / L hydrochloric acid, wherein the washing volume is 3 to 5 column volumes.

Description

Technical Field

[0001] The invention belongs to the technical field of preparation of Pb-212, and specifically relates to a method for extracting Pb-212 from a radium solution. Background Art

[0002] The statements herein merely provide background information related to the present invention and do not necessarily constitute prior art.

[0003] Pb-212 has significant advantages in treating tumors. In recent years, it has become one of the two most popular targeted therapeutic alpha nuclides along with Ac-225 (Actinium-225). Its high energy transfer efficiency helps to achieve more effective nuclear medicine dose delivery. Moreover, compared with Ac-225, it does not have a complex decay chain, and the off-target toxicity caused by the recoil of daughter nuclei and the toxic side effects caused by the daughter nuclei in the distribution are smaller, and the design of the chelate is relatively simple. Pb-212 can be separated and purified from natural thorium series, nuclear fuel irradiated by reactors, U-232 decay daughters, and produced by accelerators.

[0004] In the process of producing Ac-225 by proton irradiation thorium target, not only Ra-223 (radium-223) by-products will be produced, but also a large amount of Th-228 (thorium-228) and Ra-224 (radium-224) will be produced, both of which can be used as the precursor for producing Pb-212. In the process of separating Ac from the irradiated thorium target, Th, which accounts for more than 99.9% of the mass, is first separated from other trace elements, and a large amount of matrix thorium solution containing Th-228 and trace elements containing radium and actinium are obtained. Then radium and actinium are separated to obtain crude radium and crude actinium products. Other impurity elements such as Ba, Sr, Pb, Pd, Rb in the crude radium product are removed to obtain a product of higher purity Ra. Then wait for Ra-224 to decay into Pb-212 to obtain Pb-212 with higher radioactive nucleus purity. The Ra leakage rate needs to be reduced during the separation process, otherwise the Ra impurity content in the Pb product will increase, the purity of the Pb-212 product will decrease, and the subsequent ligand labeling rate of the nuclide will decrease. Ra contains a certain proportion of Ra-225, and the β rays it brings will cause unnecessary damage to human tissues. Summary of the invention

[0005] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a method for extracting Pb-212 from a radium solution.

[0006] In order to achieve the above object, the present invention is implemented through the following technical solutions:

[0007] A method for extracting Pb-212 from a radium solution comprises the following steps:

[0008] removing the matrix thorium and actinium in the proton irradiated thorium target in sequence to obtain a crude radium product solution;

[0009] After removing impurity elements from the crude radium product liquid, a Ra product liquid is obtained;

[0010] The Ra product solution is placed for a set time to allow the activity of its daughter Pb-212 to reach the required level;

[0011] Adjust the nitric acid concentration of the Ra product solution to 0.001-0.01 mol / L;

[0012] The dilution was passed through a TK100 resin column loaded with di-tert-butyl dicyclohexyl-18-crown-6 and di(2-ethylhexyl) phosphate extractants;

[0013] The TK100 resin column was washed with 0.001-0.01 mol / L nitric acid in a washing volume of 3-5 column volumes; and then the TK100 resin column was washed with 5.5-6.5 mol / L hydrochloric acid in a washing volume of 3-5 column volumes.

[0014] After leaving the Ra element for several days, the activity of the daughter Pb-212 is the highest, but the mass proportion of Ra in the mixed solution is still dominant, with only a small amount of Pb-212. The mass proportions of the two elements are very different. Many separation methods can easily cause Ra leakage during separation, resulting in a higher Ra impurity content in the Pb-212 product.

[0015] In the present invention, the acidity of the solution is adjusted to low acid, and the solution is passed through a TK100 resin column, the extractant loaded on the TK100 resin column is a mixture of di-tert-butyl dicyclohexyl-18-crown-6 and di(2-ethylhexyl) phosphate; the particle size of the resin particles is 100-150 μm, the column loading speed of the solution is 0.5-1 mL / min, Ra is adsorbed on the column, and Pb-212 flows out with the solution.

[0016] Specifically, the nitric acid concentration of the Ra product solution is adjusted to 0.001-0.01 mol / L and passed through the TK100 resin column. Within this acidity range, Ra can be relatively completely adsorbed, and most impurities are retained in the effluent. If the nitric acid concentration of the Ra product solution is too high or too low, the adsorption capacity of Ra will decrease to varying degrees.

[0017] Then, the column is washed with 0.001-0.01 mol / L nitric acid at a speed of 1 mL / min and a washing volume of 2-3 column volumes, which can clean the small amount of impurities adsorbed on the column. Then, 5.5-6.5 mol / L hydrochloric acid is used for elution. Within this acidity range, the column has a weak adsorption capacity for Pb-212 and is easier to desorb. The elution speed is 0.5-1.5 mL / min and the elution volume is 3-5 column volumes, which can completely elute the Pb-212 on the column to obtain a Pb-212 product with higher purity.

[0018] In some embodiments, the loading rate of the diluent through the TK100 resin column is 0.5-1 mL / min.

[0019] In some embodiments, the extractant loaded on the TK100 resin column is a mixture of di-tert-butyldicyclohexyl-18-crown-6 and di(2-ethylhexyl)phosphate.

[0020] Preferably, the particle size of TK100 resin is 100-150 μm.

[0021] The methods for preparing Ra product solution include cationic resin column purification, TK101 purification, and TK102 purification.

[0022] In some embodiments, the impurity elements in the crude radium product solution are removed to prepare the Ra product solution by:

[0023] The nitric acid concentration in the crude radium product solution is adjusted to 0.4-0.6 mol / L to ensure that all elements can be loaded onto the column, and then the radium product solution is passed through a cationic resin column, wherein the resin of the cationic resin column is cross-linked styrene-divinylbenzene, and the exchange group is sulfonate;

[0024] Then 0.2-0.4 mol / L citric acid is used to elute the cationic resin column. Sr, Pb, La and Pd are eluted first, followed by Ba, and finally Ra, thus completing the separation of Ra from other elements.

[0025] Ra has similar chemical properties to elements of the same group, and is difficult to separate. The present invention utilizes the different complexing abilities of complexing agents for different alkaline earth metals to achieve the purpose of separation from other elements.

[0026] Preferably, the model of the cationic resin is DOWEX50-X8, AG50W-X8 or AGMP-50.

[0027] Preferably, the cationic resin has a particle size of 200-400 meshes.

[0028] Preferably, the pH value of the citric acid is 3-6.

[0029] In some embodiments, the impurity elements in the crude radium product solution are removed to prepare the Ra product solution by:

[0030] The nitric acid concentration in the crude radium product solution was adjusted to 0.04-0.06 mol / L, and then passed through a TK101 resin column;

[0031] The TK101 resin column was washed with 0.04-0.06 mol / L nitric acid, and the elution volume was 2 column volumes;

[0032] Then, 2.5-3.5 mol / L nitric acid was used to elute the TK101 resin column with an elution volume of 6-8 column volumes to obtain a Ra product solution.

[0033] The TK101 resin column was washed with 0.04-0.06 mol / L nitric acid to elute the elements such as Ba, Sr, Pb, and La adsorbed on the TK101 resin column.

[0034] Then, 2.5-3.5 mol / L nitric acid was used to elute the TK101 resin column with a elution volume of 6-8 column volumes to elute Ra and obtain a pure Ra product solution.

[0035] Ba was eluted with 6-8 mol / L nitric acid, the elution volume was 4-5 column volumes, and the elution rate was 0.5-1 mL / min.

[0036] Preferably, the particle size of TK101 resin is 100-150 μm.

[0037] The beneficial effects achieved by one or more embodiments of the present invention are as follows:

[0038] (1) TK100 resin was used for the separation of Ra and Pb for the first time. The recovery rate of Pb-212 was close to 97% and the decontamination coefficient was >10 3 , which better achieved the decontamination of Ra in Pb;

[0039] (2) In the Ra purification stage and Ra / Pb separation stage, cationic resin / TK101 / TK102+TK100 is used to purify the crude radium product and extract Pb. This effectively reduces the elemental proportion of the parent element Ra in the Pb-212 product solution, which will increase the radioactive nuclear purity of Pb-212 and is more conducive to the labeling experiment of drug ligands. DETAILED DESCRIPTION

[0040] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0041] The method for removing matrix thorium from proton irradiated thorium target is:

[0042] The anion resin column thorium removal method is used to remove a large amount of matrix thorium. Specifically, under high concentration nitric acid conditions, thorium, uranium, protactinium and other elements form complex anions with nitrate and are adsorbed on the column, while radium, actinium and other impurity elements flow out with the effluent. The concentration of thorium solution is reduced from 100 g / L to 10 -5 g / L, the decontamination factor for thorium is about 10 7 .

[0043] The anion resin used in the thorium removal process is DOWEX1-X8 or AGMP-1M, the resin particle size is 100-200 mesh, 200-400 mesh, and the resin exchange ion is nitrate. The acidity of the thorium solution on the column is 7-7.5mol / L nitric acid or 7.5-8mol / L nitric acid, and the flow rate is about 0.4-0.8mL / min. Then wash the separation column with 2-4 column volumes of nitric acid solution, the acidity is 7-7.5mol / L nitric acid, 7.5-8mol / L nitric acid, and the flow rate is about 0.4-0.8mL / min. Finally, elute the elements on the column with 0.01mol / L-0.1mol / L nitric acid.

[0044] The method to remove the actinium is:

[0045] One method is: adjust the acidity of radium, actinium and other impurity element solutions to 0.5 mol / L, pass the solution through a cationic resin column, and the column flow rate is 0.1-0.2 mol / L. The cationic resin model is DOWEX50-X8, AG50W-X8 or AGMP-50, or other strong alkaline cationic resins with similar functions. The resin is cross-linked styrene-divinylbenzene, the exchange group is sulfonic acid, and the exchange ion is hydrogen ion. The resin particle size is 100-200 mesh.

[0046] The separation column is then washed with 2-3 mol / L nitric acid to separate divalent elements such as radium and trivalent elements such as actinium. The washing volume is 12-18 column volumes. Divalent elements such as radium are washed out first, followed by trivalent elements such as actinium. Thorium is left on the separation column and can be eluted with 4-5.5 mol / L nitric acid at a flow rate of 0.5-1 mL / min.

[0047] Method 2 is: adjust the acidity of radium, actinium and other impurity element solutions to 2 mol / L. The resin material, column flow rate and washing flow rate are the same as those in method 1. The washing volume is 10-15 column volumes. The washing behavior of the elements remains unchanged. The divalent elements are washed out first, and the trivalent elements are washed out later. Thorium is retained on the column and can be eluted with 4-5.5 mol / L nitric acid later at a flow rate of 0.5-1 mL / min.

[0048] After the above method is completed, a crude radium product liquid is obtained, and a mixed solution of radium and impurity elements such as barium, strontium, lead, palladium, and tin is obtained.

[0049] The present invention will be further described below in conjunction with the embodiments.

[0050] Example 1

[0051] Ba (simulating Ra), Sr, Pb, and La (simulating Ac) were used to prepare simulated solutions of crude radium product liquid, with concentrations of Sr-50ppm, Ba-32ppm, Pb-50ppm, and La-12ppm, respectively. The solution acidity was 0.5mol / L nitric acid, and the solution volume was 10mL.

[0052] The solution was passed through AG50W-X8 resin with a resin particle size of 200-400 mesh, a resin volume of 1 mL, and a column loading speed of 0.3 mL / min.

[0053] Then, the AG50W-X8 resin column was eluted with 0.25 mol / L citric acid solution at pH 5 at a rate of 0.5 mL / min, and 10 mL of eluent 1 (containing La, Sr, and Pb), 10 mL of eluent 2 (containing Ba), and 15 mL of eluent 3 (corresponding to Ra solution) were obtained in turn. The decontamination coefficients of Ba for Sr, Pb, and La were 5600, 2000, and 6000, respectively.

[0054] The chemical properties of Ba and Ra are very similar. Ba is used to simulate the properties of Ra, and a simulated solution of Ra-224 and Pb-212 in equilibrium is prepared: the Ba concentration is 28ppm, the Pb-212 concentration is 3ppm, the solution acidity is 0.005mol / L nitric acid, and the volume is 10mL.

[0055] The simulated solution was passed through TK100 resin with a particle size of 100 microns and a column loading rate of 0.75 mL / min, and Ba was adsorbed on the column. The column was washed with 0.005 mol / L nitric acid at a washing rate of 1 mL / min and a washing volume of 2 column volumes to elute other trace impurities contained in Ba. Finally, Pb adsorbed on the resin column was eluted with 6 mol / L hydrochloric acid at a elution rate of 1 mL / min and an elution volume of 5 column volumes.

[0056] The final decontamination coefficient of Pb for Ba is 1800. The decontamination coefficients of Ba for Sr, Pb and La are 2400, 1100 and 2000 respectively. The element purity of Pb is 99.98% and the recovery rate is 98.2%.

[0057] Example 2

[0058] A simulated solution of the crude radium product liquid was prepared using Ba (simulating Ra), Sr, Pb, and La (simulating Ac), with concentrations of Sr-50ppm, Ba-32ppm, Pb-50ppm, and La-12ppm, respectively. The acidity was adjusted to 0.05mol / L nitric acid, a total of 10mL, and passed through TK101 resin with a resin particle size of 100-150 microns, a resin volume of 0.5mL, and a column loading speed of 0.7mL / min.

[0059] Then, the separation column was eluted with 0.05 mol / L nitric acid solution at a rate of 0.5 mL / min and a elution volume of 10 column volumes to obtain a total of 15 mL of La, Sr, Pb, and Pd washing solutions. The separation column was then eluted with 3 mol / L nitric acid to obtain a total of 15 mL of Ba eluate at a rate of 0.5 mL / min.

[0060] The chemical properties of Ba and Ra are very similar. Ba is used to simulate the properties of Ra. A simulated solution of Ra-224 and Pb-212 in equilibrium is prepared. The Ba concentration is 28 ppm, the Pb concentration is 3 ppm, the solution acidity is 0.008 mol / L nitric acid, and the volume is 10 mL.

[0061] The simulated solution was passed through TK100 resin with a particle size of 100 microns and a column loading rate of 0.75 mL / min, and Ba was adsorbed on the column. The column was washed with 0.008 mol / L nitric acid at a rate of 1 mL / min and a washing volume of 2 column volumes to wash off other trace impurities contained in Ba. Finally, Pb adsorbed on the resin column was eluted with 5.5 mol / L hydrochloric acid at a rate of 1 mL / min and an elution volume of 5 column volumes.

[0062] The final decontamination coefficient of Ba in Pb was 1800, the element purity of Pb was 99.97%, and the recovery rate was 96.5%.

[0063] Example 3

[0064] Relative to Example 2, the acidity of the simulated solutions of Ba, Sr, Pb, La, and Pd was adjusted to 0.05 mol / L, a total of 10 mL, passed through DOWEX50-X8 resin with a resin particle size of 200 mesh, a resin volume of 1 mL, and a column loading speed of 0.2 mL / min.

[0065] Then, the separation column was eluted with 0.25 mol / L citric acid solution with a pH of 5 at a rate of 0.2 mL / min, and 10 mL of eluent 1 (containing La, Sr, Pb, and Pd), 10 mL of eluent 2 (containing Ba), and 15 mL of eluent 3 (corresponding to Ra solution) were obtained. The decontamination coefficients of Ba for Sr, Pb, and La were 2400, 800, and 3000, respectively.

[0066] The chemical properties of Ba and Ra are very similar. Ba is used to simulate the properties of Ra. A simulated solution of Ra-224 and Pb-212 in equilibrium is prepared. The Ba concentration is 28 ppm, the Pb concentration is 3 ppm, the solution acidity is 0.002 mol / L nitric acid, and the volume is 10 mL.

[0067] The simulated solution was passed through TK100 resin with a particle size of 100 microns and a column loading rate of 0.75 mL / min, and Ba was adsorbed on the column. The column was washed with 0.002 mol / L nitric acid at a washing rate of 1 mL / min and a washing volume of 2 column volumes to elute other trace impurities contained in Ba. Finally, Pb adsorbed on the resin column was eluted with 6.5 mol / L hydrochloric acid at a elution rate of 1 mL / min and an elution volume of 5 column volumes.

[0068] The element purity of Pb was 99.98% and the recovery rate was 98.1%.

[0069] Comparative Example 1

[0070] Ba (simulating Ra), Sr, Pb, La (simulating Ac) were used to prepare a simulated solution of the crude radium product solution, with concentrations of Sr-50ppm, Ba-32ppm, Pb-50ppm, La-12ppm, respectively, the solution acidity was 0.5mol / L nitric acid, and the solution volume was 10mL. Same as Example 1.

[0071] Relative to Example 1, the pre-impurity removal step of AG50W-X8 resin was omitted, and the TK100 resin was directly passed through, with a column loading speed of 0.75 mL / min, and part of the Ba flowed out with the solution. The column was washed with 0.005 mol / L nitric acid at a washing speed of 1 mL / min and a washing volume of 5 column volumes to elute all the Ba. Finally, the Pb adsorbed on the resin column was eluted with 6 mol / L hydrochloric acid at a elution speed of 1 mL / min and an elution volume of 5 column volumes. The experimental results show that Pb cannot be effectively separated from other elements.

[0072] Comparative Example 2

[0073] A simulated solution of the crude radium product solution was prepared using Ba (simulating Ra), Sr, Pb, and La (simulating Ac), with concentrations of Sr-50ppm, Ba-32ppm, Pb-50ppm, and La-12ppm, respectively. The solution acidity was 0.5mol / L nitric acid, and the solution volume was 10mL, the same as in Example 1.

[0074] The solution was passed through DOWEX50-X8 resin with a resin particle size of 200 mesh, a resin volume of 1 mL, and a column loading speed of 0.3 mL / min.

[0075] Then, the separation column was eluted with 0.25 mol / L citric acid solution with a pH of 5 at a rate of 0.5 mL / min, and 10 mL of eluent 1 (containing La, Sr, and Pb), 10 mL of eluent 2 (containing Ba), and 15 mL of eluent 3 (which should be Ra solution) were obtained. The decontamination coefficients of Ba for Sr, Pb, and La were 2400, 800, and 3000, respectively.

[0076] The chemical properties of Ba and Ra are very similar. Ba is used to simulate the properties of Ra. A simulated solution of Ra-224 and Pb-212 in equilibrium is prepared. The Ba concentration is 28 ppm, the Pb concentration is 3 ppm, the solution acidity is 0.1 mol / L nitric acid, and the volume is 10 mL.

[0077] The simulated solution was passed through DOWEX50-X8 resin, with a resin particle size of 200 meshes, a resin volume of 1 mL, and a column loading speed of 0.5 mL / min. Then, the separation column was eluted with a 0.25 mol / L, pH 5 citric acid solution at a rate of 0.5 mL / min, and a total of 10 mL of Pb eluate and 15 mL of Ba eluate were obtained. The decontamination coefficient of Ba in Pb was 200, and the final elemental purity of Pb was 99.5%, and the recovery rate was 98%.

[0078] Comparative Example 3

[0079] The difference from Example 1 is that the simulated solution is passed through TK100 resin with a particle size of 100 μm and a column loading speed of 0.75 mL / min, and Ba is adsorbed on the column. The column is washed with 0.011 mol / L nitric acid at a washing speed of 1 mL / min and a washing volume of 2 column volumes to wash off other trace impurities contained in Ba. Finally, Pb adsorbed on the resin column is eluted with 6 mol / L hydrochloric acid at a elution speed of 1 mL / min and an elution volume of 5 column volumes.

[0080] The final element purity of Pb was 99.7% and the recovery rate was 98.1%.

[0081] Comparative Example 4

[0082] The difference from Example 1 is that the simulated solution is passed through TK100 resin with a particle size of 100 μm and a column loading speed of 0.75 mL / min, and Ba is adsorbed on the column. The column is washed with 0.0007 mol / L nitric acid at a washing speed of 1 mL / min and a washing volume of 2 column volumes to wash off other trace impurities contained in Ba. Finally, Pb adsorbed on the resin column is eluted with 6 mol / L hydrochloric acid at a elution speed of 1 mL / min and an elution volume of 5 column volumes.

[0083] The final element purity of Pb was 99.73% and the recovery rate was 97.15%.

[0084] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for extracting Pb-212 from a radium solution, characterized in that: The steps include: removing the matrix thorium and actinium in the proton irradiated thorium target in sequence to obtain a crude radium product solution; After removing impurity elements from the crude radium product liquid, a Ra product liquid is obtained; The Ra product solution is placed for a set time to allow the activity of its daughter Pb-212 to reach the required level; Diluting the Ra product solution to obtain a dilution solution, so that the nitric acid concentration in the dilution solution reaches 0.001-0.01 mol / L; The dilution was passed through a TK100 resin column loaded with di-tert-butyl dicyclohexyl-18-crown-6 and di(2-ethylhexyl) phosphate extractants; The TK100 resin column was washed with 0.008-0.01 mol / L nitric acid in a washing volume of 3-5 column volumes; and then the TK100 resin column was washed with 5.5-6.5 mol / L hydrochloric acid in a washing volume of 3-5 column volumes.

2. The method for extracting Pb-212 from a radium solution according to claim 1, characterized in that: The loading speed of the diluent through the TK100 resin column is 0.5-1 mL / min.

3. The method for extracting Pb-212 from a radium solution according to claim 2, characterized in that: The extractant loaded on the TK100 resin column was a mixture of di-tert-butyl dicyclohexyl-18-crown-6 and di(2-ethylhexyl) phosphate; Preferably, the particle size of TK100 resin is 100-150 μm.

4. The method for extracting Pb-212 from a radium solution according to claim 1, characterized in that: The method for removing impurity elements in the crude radium product solution to prepare the Ra product solution is as follows: The nitric acid concentration in the crude radium product solution is adjusted to 0.4-0.6 mol / L, and then the solution is passed through a cationic resin column, wherein the resin of the cationic resin column is cross-linked styrene-divinylbenzene, and the exchange group is a sulfonate group; Then 0.2-0.4 mol / L citric acid is used to elute the cationic resin column. Sr, Pb, La and Pd are eluted first, followed by Ba, and finally Ra, thus completing the separation of Ra from other elements.

5. The method for extracting Pb-212 from a radium solution according to claim 4, characterized in that: The model of the cationic resin is DOWEX50-X8, AG50W-X8 or AGMP-50.

6. The method for extracting Pb-212 from a radium solution according to claim 5, characterized in that: The particle size of the cationic resin is 200-400 mesh.

7. The method for extracting Pb-212 from a radium solution according to claim 4, characterized in that: The pH value of the citric acid is 3-6.

8. The method for extracting Pb-212 from a radium solution according to claim 1, characterized in that: The method for removing impurity elements in the crude radium product solution to prepare the Ra product solution is as follows: The nitric acid concentration in the crude radium product solution was adjusted to 0.04-0.06 mol / L, and then passed through a TK101 resin column; The TK101 resin column was washed with 0.04-0.06 mol / L nitric acid, and the elution volume was 2 column volumes; Then, the TK101 resin column was eluted with 2.5-3.5 mol / L nitric acid at a volume of 6-8 column volumes to obtain a Ra product solution.

9. The method for extracting Pb-212 from a radium solution according to claim 8, characterized in that: The extractant loaded on the TK101 resin column is a mixture of di-tert-butyl dicyclohexyl-18-crown-6 and di(2-ethylhexyl) phosphate.

10. The method for extracting Pb-212 from a radium solution according to claim 8, characterized in that: The particle size of TK101 resin is 100-150μm.