Process and apparatus for purification of actinium

Abstract

The application discloses a purification method and device of actinium, and belongs to the technical field of medical radioisotope separation and purification. 3+ The first effluent liquid containing Ac 3+ The first effluent liquid containing Ac 3+ The second effluent liquid containing Ac 3+ The second effluent liquid containing Ac 3+ The TK221 resin contains phosphine oxide and a small amount of long-alkyl-chain alcohol on the basis of diglycolamide, and shows good performance in the purification of Ac 225 Meanwhile, the elution acidity in the separation process of the TRU resin is properly improved, the effusion speed of Ac, La and Ce is delayed, the effect of separating Ac from La and Ce is achieved, the concentration of metal impurities is reduced, and the yield of Ac is improved.

Description

Technical Field

[0001] This invention belongs to the field of medical radioisotope separation and purification technology, specifically relating to a purification method and apparatus for actinium. Background Technology

[0002] The information disclosed in this background section is intended only to enhance understanding of the overall background of the invention and is not necessarily to be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art.

[0003] Targeted alpha particle therapy (TAT) uses transporters such as peptides, monoclonal antibodies, or modular nanotransporters to selectively deliver radiopharmaceuticals that emit alpha particles to cancer cells and the tumor microenvironment. This controls the tumor while minimizing toxicity, and is considered one of the most advanced treatment methods for malignant tumors. Actinide-225 ( 225 Ac) is a radioactive nuclide that can be used in TAT.

[0004] Current production 225 The main method for producing Ac is to irradiate a natural thorium target with medium-energy protons (90-135 MeV). 225 Ac. However, separating actinium from an irradiated thorium target is a laborious process because it generates a large number of different fission products, especially those with chemical properties different from Ac. 3+ Similar rare earth elements (REEs) are difficult to separate.

[0005] Currently, the extraction of actinium from irradiated thorium targets typically involves two steps. The first step is the removal of a large amount of thorium, which can be achieved through precipitation, anion exchange, cation exchange, etc. The second step is the purification of actinium, primarily involving separation from alkaline earth metals, lanthanides, and other actinides. In actinium purification, DGA resin is commonly used to remove a large amount of alkaline earth metal ions and other ions, and finally, TRU resin is used to remove lanthanides, thereby obtaining purified Actinium (Ac). 3+ However, due to the limitations of DGA resin separation performance, some impurity ions, such as Sr... 2+ Pb 2+ Will follow Ac 3+ The eluent flows out and cannot be separated in the subsequent TRU resin separation process.

[0006] Therefore, there is an urgent need to develop new... 225 Ac separation technology reduces the impurity metal content in actinide products. Summary of the Invention

[0007] To address the shortcomings of existing technologies, the present invention aims to provide a method and apparatus for purifying actinium. The method provided by the present invention can reduce the content of impurity metals while improving the recovery rate of actinium.

[0008] To achieve the above objectives, the technical solution of the present invention is as follows:

[0009] A first aspect of the present invention provides a method for purifying actinium, comprising the following steps:

[0010] A thorium target solution containing actinium was passed through a cation exchange column and eluted with a weak organic acid and an inorganic acid to obtain a solution containing Actinium. 3+ The first effluent;

[0011] Will contain Ac 3+ The first effluent was extracted using a TK221 resin extraction column to obtain a solution containing Ac. 3+ The second effluent;

[0012] Will contain Ac 3+ The second effluent was extracted with a TRU resin column to obtain actinium.

[0013] A second aspect of the present invention provides an apparatus for purifying actinium, comprising:

[0014] The first obtaining unit includes a cation exchange column for passing a thorium target solution through and washing with an inorganic acid to obtain a solution containing Ac. 3+ The first effluent;

[0015] The second obtaining unit includes a TK221 resin extraction column for extracting resin containing Ac. 3+ The first effluent is passed through and washed with an inorganic acid to obtain a solution containing Ac. 3+ The second effluent;

[0016] The third obtaining unit includes a TRU resin extraction column for extracting substances containing Ac 3+ The second effluent was passed through and washed with inorganic acid to obtain purified actinium product.

[0017] The beneficial effects of this invention are as follows:

[0018] This invention provides a method and apparatus for purifying actinium by combining TK221 and TRU resins. The functional component of the DGA resin is N,N,N',N'-tetra-n-octyl-diethylene glycolamide (DGA-N resin) or N,N,N',N'-tetra-2-ethylhexyl-diethylene glycolamide (DGA-B resin). The TK221 resin, in addition to diethylene glycolamide, also contains phosphine oxide and a small amount of long alkyl chain alcohols, which are effective for the purification of actinium. 3+ The purification process showed good performance. Simultaneously, this invention appropriately increases the elution acidity during the TRU resin separation process, slowing down the elution rates of Ac, La, and Ce, thereby achieving the effect of separating Ac from La and Ce, reducing the concentration of metal impurities while improving… 225 The yield of Ac. Attached Figure Description

[0019] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0020] Figure 1 This is a process flow diagram of the actinium purification method used in the embodiments of the present invention. Detailed Implementation

[0021] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0022] This invention does not impose any special restrictions on the source of any experimental raw materials; they can be purchased from the market or prepared using conventional methods known to those skilled in the art.

[0023] A first typical embodiment of the present invention provides a method for purifying actinium, comprising the following steps:

[0024] A thorium target solution containing actinium was passed through a cation exchange column and eluted with a weak organic acid and an inorganic acid to obtain a solution containing Actinium. 3+ The first effluent;

[0025] Will contain Ac 3+ The first effluent was extracted using a TK221 resin extraction column to obtain a solution containing Ac. 3+ The second effluent;

[0026] Will contain Ac 3+ The second effluent was extracted with a TRU resin column to obtain actinium.

[0027] Besides thorium nitrate and actinium, other impurities in the thorium target solution mainly include alkaline earth metals, lanthanides, and other actinides (Sr) plasma. 2+ Ba 2+ Pb 2+ La 3+ Ce 3+ (etc.). In the purification of actinium, DGA resin is commonly used to remove a large number of alkaline earth metal ions and other ions, and TRU resin is finally used to remove lanthanides, thereby obtaining purified Ac. 3+ However, due to the limitations of DGA resin separation performance, some impurity ions, such as Sr... 2+ Pb 2+ Will follow Ac 3+The eluent flows out and cannot be separated in the subsequent TRU resin separation process. This invention uses a combination of TK221 resin and TRU resin to reduce the concentration of impurity metals while improving the yield of actinium products. TK221 resin, in addition to diethylene glycol amide, also contains phosphine oxide and a small amount of long alkyl chain alcohols, which are beneficial for Ac... 3+ The purification process showed good performance. Simultaneously, appropriately increasing the elution acidity during the TRU resin separation process can slow down the elution rate of Ac, La, and Ce, thereby achieving the effect of separating Ac from La and Ce.

[0028] In some embodiments of this implementation, the method for preparing the thorium target solution includes the following steps:

[0029] The irradiated thorium target was dissolved in nitric acid and hydrofluoric acid, evaporated to near dryness, and then redissolved in citric acid and the pH was adjusted to 1-3 to obtain the thorium target solution.

[0030] Among them, irradiated thorium targets are dissolved using nitric acid and hydrofluoric acid at 75-85℃.

[0031] The concentration of the nitric acid is 8-10 M, more preferably 8 M.

[0032] The concentration of the hydrofluoric acid is 0.05-0.1M, more preferably 0.1M.

[0033] The concentration of citric acid is 0.4-0.6M, more preferably 0.5M.

[0034] In some embodiments of this implementation, the packing material of the cation exchange column includes AG50W-X8 cation exchange resin or any sulfonated styrene-divinylbenzene copolymer with a crosslinking degree greater than 4. Resins with higher crosslinking degrees have a larger adsorption capacity for the elements to be adsorbed, higher strength, and better selectivity, thus enabling better removal of thorium.

[0035] In some embodiments of this implementation, the particle size of the cation exchange resin in the cation exchange column is 200-400 mesh. The mesh number of the resin represents the resin particle size; resin particles with larger mesh numbers exhibit higher selectivity, which is beneficial for improving the separation coefficient of thorium from other elements. Within the 200-400 mesh range, the separation effect of thorium from other elements is relatively good.

[0036] In some embodiments of this implementation, the mass ratio of the thorium target, the actinium-containing thorium target solution, and the cation exchange resin packed in the cation exchange column is (19-21):(29-31):1, preferably 20:30:1; the amount of resin packed in the TK221 resin extraction column and the TRU resin extraction column is 0.9-1.1 mL, preferably 1 mL.

[0037] In some embodiments of this implementation, a thorium target solution containing actinium is passed through a cation exchange column and eluted with a weak organic acid and an inorganic acid to obtain a solution containing Actinium. 3+ The first effluent includes the following steps:

[0038] A cation exchange column was prepared and pre-washed with a first organic acid. Thorium target solution was added to the cation exchange column, which was then washed first with the first organic acid, followed by washing with a first inorganic acid. Finally, the cation exchange column was eluted with a second inorganic acid, and the effluent was collected to obtain a solution containing Ac. 3+ The first effluent. The above operation allows the cation exchange resin to separate the thorium target solution, effectively removing thorium from the solution.

[0039] The preparation of the cation exchange column includes the following steps: AG50W-X8 cation exchange resin (200-400 mesh, H...) + The sample (of type) is soaked overnight in 1.5-2.5M (preferably 2M) nitric acid, then washed with deionized water, and subsequently packed into an empty column. 4-6 BV (preferably 5 BV) of saturated NH4Cl solution is added to convert it to NH4. + The cation exchange column was obtained by [method name missing].

[0040] During the pre-washing and washing processes, the flow rate is 0.2-0.6 mL / min, preferably 0.5 mL / min.

[0041] The first organic acid is a citric acid solution with a concentration of 0.4-0.6 M (pH ~ 2), preferably 0.5 M. If the acidity is too high, the hydrogen ion concentration in the solution is very high, preventing the hydrogen ions on the cation exchange column from exchanging with thorium, potentially causing thorium leakage. If the acidity is too low, other low-valence elements will be adsorbed onto the column, reducing the recovery rate of the target element. During pre-washing, the amount of the first organic acid used is 3-5 BV, preferably 4 BV. The purpose of pre-washing is to balance the acidity. When washing the cation exchange column with the first organic acid, the amount of the first organic acid used is 25-35 BV, preferably 30 BV. Washing the cation exchange column with the first organic acid can remove a large amount of thorium from the target solution.

[0042] The first inorganic acid is a nitric acid solution with a concentration of 1-2M, preferably 1.8M. When washing the cation exchange column with the first inorganic acid, the amount of the first inorganic acid used is 25-35 BV, preferably 30 BV. Washing with the first inorganic acid can remove most of the monovalent and divalent ions in the target solution.

[0043] The second inorganic acid is a nitric acid solution with a concentration of 5-7M, preferably 6M. When washing the cation exchange column with the second inorganic acid, the amount of the second inorganic acid used is 15-25 BV, preferably 20 BV. Washing with the second inorganic acid can remove Ac... 3+ It elutes out along with other residual ions on the resin column.

[0044] In some embodiments of this implementation, Ac will be included 3+ The first effluent was extracted using a TK221 resin extraction column to obtain a solution containing Ac. 3+ The second effluent specifically includes the following steps:

[0045] Solid-phase extraction column I was prepared using TK221 resin and pre-washed with a third inorganic acid; a column containing Ac was then added. 3+ The first effluent was adjusted to a pH of the third inorganic acid using deionized water and then added to the solid-phase extraction column I. The column I was first washed with the third inorganic acid, then with the fourth inorganic acid, and the effluent was collected. After evaporation to near dryness, the effluent was redissolved with the third inorganic acid to obtain a solution containing Ac. 3+ The second effluent.

[0046] The preparation of solid-phase extraction column I using TK221 resin includes the following steps:

[0047] TK221 resin was packed into an empty column, and 5-7M (preferably 6M) nitric acid was pumped in and soaked overnight. The column was then washed with a large amount of deionized water to obtain solid phase extraction column I.

[0048] During the pre-washing and washing processes, the flow rate is 0.2-0.6 mL / min, preferably 0.5 mL / min.

[0049] The third inorganic acid is a nitric acid solution with a concentration of 3-5M, preferably 4M. During pre-washing, the amount of the third inorganic acid used is 4-6 BV, preferably 5 BV. When washing the solid-phase extraction column I with the third inorganic acid, the amount of the third inorganic acid used is 20-30 BV, preferably 25 BV. Washing the solid-phase extraction column I with the third inorganic acid can remove impurity ions other than lanthanides and actinides, such as Sr, Ba, and Pb.

[0050] The fourth inorganic acid is a nitric acid solution with a concentration of 0.008-0.012M, preferably 0.01M. When washing the solid-phase extraction column I with the fourth inorganic acid, the amount of the fourth inorganic acid used is 45-55 BV, preferably 50 BV. Washing the solid-phase extraction column I with the fourth inorganic acid can elute a mixed solution of Ac, La, and Ce.

[0051] In some embodiments of this implementation, Ac will be included3+ The second effluent is extracted using a TRU resin extraction column to obtain actinium, specifically through the following steps:

[0052] Solid-phase extraction column II was prepared using TRU resin and pre-washed with a third inorganic acid; a column containing Ac was then added. 3+ The second effluent was added to the solid-phase extraction column II, and the solid-phase extraction column II was washed with a third inorganic acid. The first 10 BV of effluent was collected, evaporated to dryness, and then redissolved in 0.1 M hydrochloric acid to obtain the actinium product.

[0053] The preparation of the solid-phase extraction column II using TRU resin includes the following steps:

[0054] TRU resin was packed into an empty column, and 3-5M (preferably 4M) nitric acid was pumped in and soaked overnight. The column was then washed with a large amount of deionized water to obtain solid phase extraction column II.

[0055] During the pre-washing and washing processes, the flow rate is 0.1-0.3 mL / min, preferably 0.2 mL / min.

[0056] The third inorganic acid is a nitric acid solution with a concentration of 2-4M, preferably 4M. During pre-washing, the amount of the third inorganic acid used is 4-6 BV, preferably 5 BV. When washing the solid-phase extraction column II with the third inorganic acid, the amount of the third inorganic acid used is 8-12 BV, preferably 10 BV. When washing the solid-phase extraction column II with the third inorganic acid, Ac elutes from the TRU resin column before La and Ce, and the first 10 column volumes of effluent yield a high-purity Ac solution.

[0057] A second typical embodiment of the present invention provides an apparatus for purifying actinium, comprising:

[0058] The first obtaining unit includes a cation exchange column for passing a thorium target solution through, and washing with an inorganic acid to obtain a solution containing Ac. 3+ The first effluent;

[0059] The second obtaining unit includes a method for obtaining Ac 3+ The first effluent was passed through a TK221 resin extraction column to obtain a product containing Ac. 3+ The second effluent;

[0060] The third obtaining unit includes a method for obtaining Ac 3+ The second effluent was passed through a TRU resin extraction column to obtain actinium product.

[0061] Since the protection provided by this device is similar to that provided by the method described above, it will not be described in detail here. Please refer to the discussion section of the method described above for more information.

[0062] To enable those skilled in the art to better understand the technical solution of the present invention, the technical solution of the present invention will be described in detail below with reference to specific embodiments.

[0063] The apparatus and materials used in the following examples and comparative examples are all commercially available products. Specifically, TK221 resin is a commercially available extraction resin, manufactured by Triskem and distributed by Beijing Wodele, with a particle size of 100-200 μm.

[0064] Example 1

[0065] A method for purifying actinium includes the following steps:

[0066] (1) Target dissolution. Take 249 μL of Sr (100 ppm), 162 μL of Ba (100 ppm), 244 μL of Pb (100 ppm), 60 μL of La (100 ppm), and 34.5 μL of Ce (100 ppm) into a 15 mL centrifuge tube, add 9.25 mL of 8 M nitric acid, and prepare an impurity ion solution. Weigh 60 g of Th(NO3)4·6H2O and dissolve it in 350 mL of 8 M nitric acid. Add 200 μL of the impurity ion solution, then add... 225 200 μL of Ac nitrate solution, approximately 0.4 mCi. The prepared thorium target dissolution simulation solution was then evaporated to near dryness under heating at 80 °C, and then reconstituted with 30 mL of 0.5 M citric acid, and the pH was adjusted to 2 with ammonia.

[0067] (2) Cation column separation. 1g of AG50W-X8 cation exchange resin (200-400 mesh, H...) was added... + The resin column (approximately 1.5 mL, i.e., 1 BV = 1.5 mL) was packed into an empty column, soaked overnight in 2 M nitric acid, washed with deionized water, and then 7.5 mL of saturated NH4Cl solution was added to convert it to NH4. + Then, add 6 mL of 0.5 M citric acid (pH = 2) for column equilibration. Pump the target solution obtained in step (1) into the cation exchange column at a flow rate of 0.5 mL / min. First, elute the resin column with 45 mL of 0.5 M citric acid (pH = 2), then with 45 mL of 1.8 M nitric acid, and finally elute Ac with 30 mL of 6 M nitric acid. 3+ And collect the effluent.

[0068] (3) Solid-phase extraction 1. 1 mL of TK221 resin (approximately 0.35 g, column volume 1 mL, i.e., 1 BV = 1 mL in this step) was packed into a 1 mL empty column. 6 M nitric acid was pumped in and the column was soaked overnight. The column was then washed with a large amount of deionized water, and the acidity was equilibrated with 5 mL of 4 M nitric acid. The Ac obtained in step (2) was... 3+The effluent was adjusted to a pH of 4M nitric acid with deionized water and then added to a TK221 resin column at a flow rate of 0.5 mL / min. The column was then washed with 25 mL of 4M nitric acid, followed by elution with 50 mL of 0.01M nitric acid, and the effluent was collected. The collected liquid was evaporated to near dryness and then reconstituted with 1 mL of 4M nitric acid.

[0069] (4) Solid-phase extraction 2. 1 mL of TRU resin (approximately 0.37 g, resin column volume 1 mL, i.e., 1 BV = 1 mL in this step) was loaded into a 1 mL empty column. 4 M nitric acid was pumped in and the column was soaked overnight. The column was then washed with a large amount of deionized water, and the acidity was equilibrated with 5 mL of 4 M nitric acid. The Ac obtained in step (3) was... 3+ The eluent was added to a TRU resin column and then eluted with 10 mL of 4M nitric acid. The first 10 BV of eluent was collected. The collected eluent was evaporated at 80 °C and redissolved in 0.2 mL of 0.1M hydrochloric acid to obtain the final product suitable for biolabeling.

[0070] final 225 The recovery rate of Ac was 90.1%, with Th content of 0.72 ng / g, Sr content of 0.12 ng / g, Ba content of 0.21 ng / g, Pb content of 0.17 ng / g, La content of 0.05 ng / g, and Ce content of 0.11 ng / g.

[0071] Comparative Example 1

[0072] A method for purifying actinium includes the following steps:

[0073] (1) Target dissolution. Take 249 μL of Sr (100 ppm), 162 μL of Ba (100 ppm), 244 μL of Pb (100 ppm), 60 μL of La (100 ppm), and 34.5 μL of Ce (100 ppm) into a 15 mL centrifuge tube, add 9.25 mL of 8 M nitric acid, and prepare an impurity ion solution. Weigh 60 g of Th(NO3)4·6H2O and dissolve it in 350 mL of 8 M nitric acid. Add 200 μL of the impurity ion solution, then add... 225 200 μL of Ac nitrate solution, approximately 0.4 mCi. The prepared thorium target dissolution simulation solution was then evaporated to near dryness under heating at 80 °C, and then reconstituted with 30 mL of 0.5 M citric acid, and the pH was adjusted to 2 with ammonia.

[0074] (2) Cation column separation. 1g of AG50W-X8 cation exchange resin (200-400 mesh, H...) was added... +The resin column (type 1) was soaked overnight in 2M nitric acid, then washed with deionized water, and subsequently packed into an empty column (resin column volume approximately 15 mL, i.e., 1 BV = 15 mL). 50 mL of saturated NH4Cl solution was added to convert it to NH4. + Then, add 4 BV 0.5M citric acid (pH=2) for column equilibration. Pump the target solution obtained in step (1) into the cation exchange column at a flow rate of 0.5 mL / min. First, elute the resin column with 30 BV 0.5M citric acid (pH=2), then with 15 BV 1M nitric acid, and finally elute Ac with 20 BV 6M nitric acid. 3+ And collect the effluent.

[0075] (3) Solid-phase extraction 1. 1 mL of DGA-B resin (approximately 0.38 g) was packed into a 1 mL empty column, and 6 M nitric acid was pumped in and allowed to soak overnight. The column was then washed with a large amount of deionized water, and the acidity was equilibrated with 5 BV 6 M nitric acid. The Ac obtained in step (2) was then... 3+ The eluent was added to a DGA-B resin column, washed with 20 BV 4M nitric acid, then eluted with 50 BV 0.01M nitric acid, and the eluent was collected. The collected liquid was evaporated to near dryness and then reconstituted with 1 mL 4M nitric acid.

[0076] (4) Solid-phase extraction 2. 1 mL of TRU resin (approximately 0.37 g) was packed into a 1 mL empty column, and 4 M nitric acid was pumped in and allowed to soak overnight. The column was then washed with a large amount of deionized water, and the acidity was equilibrated with 5 mL of 2 M nitric acid. The Ac obtained in step (3) was then... 3+ The eluent was added to a TRU resin column and then eluted with 20 mL of 2M nitric acid. The eluent from the 3rd to 8th batch volume (BV) was collected. The collected eluent was evaporated at 80 °C and redissolved in 0.2 mL of 0.1M hydrochloric acid to obtain the final product suitable for biolabeling.

[0077] final 225 The recovery rate of Ac was 88.2%, with Th content of 0.41 ng / g, Sr content of 2.6 ng / g, Ba content of 0.11 ng / g, Pb content of 1.82 ng / g, La content of 2.78 ng / g, and Ce content of 0.56 ng / g.

[0078] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for purifying actinium, characterized in that, Includes the following steps: Step 1: Pass the thorium target solution containing actinium through a cation exchange column and elute with a weak organic acid and an inorganic acid to obtain a solution containing Actinium. 3+ The first effluent; Step two, containing Ac 3+ The first effluent was extracted using a TK221 resin extraction column to obtain a solution containing Ac. 3+ The second effluent; Step 3, add Ac 3+ The second effluent was passed through a TRU resin extraction column to obtain actinium; Step one specifically includes the following steps: preparing a cation exchange column and pre-washing it with a first organic acid; adding a thorium target solution to the cation exchange column, first washing the cation exchange column with a first organic acid, then washing it with a first inorganic acid, and finally eluting the cation exchange column with a second inorganic acid and collecting the effluent to obtain a solution containing Ac. 3+ The first effluent; Step two specifically includes the following steps: preparing a solid-phase extraction column I using TK221 resin and pre-washing it with a third inorganic acid; then adding the Ac... 3+ The first effluent was adjusted to a pH of the third inorganic acid using deionized water and then added to the solid-phase extraction column I. The column I was first washed with the third inorganic acid, then with the fourth inorganic acid, and the effluent was collected. After evaporation to near dryness, the effluent was redissolved with the third inorganic acid to obtain a solution containing Ac. 3+ The second effluent; Step three specifically includes the following steps: preparing a solid-phase extraction column II using TRU resin and pre-washing it with a third inorganic acid; and adding a column containing Ac... 3+ The second effluent was added to the solid-phase extraction column II, and the solid-phase extraction column II was washed with a third inorganic acid. The first 10 BV of effluent was collected, evaporated to dryness, and then redissolved in 0.1M hydrochloric acid to obtain the actinium product.

2. The purification method according to claim 1, characterized in that, The preparation method of the thorium target dissolution solution includes the following steps: The irradiated thorium target was dissolved in nitric acid and hydrofluoric acid, evaporated to near dryness, and then redissolved in citric acid and the pH was adjusted to 1-3 to obtain the thorium target solution.

3. The purification method as described in claim 2, characterized in that, The irradiated thorium target was dissolved using nitric acid and hydrofluoric acid at 75-85℃.

4. The purification method according to claim 2, characterized in that, The concentration of the nitric acid is 8-10 M.

5. The purification method as described in claim 2, characterized in that, The concentration of the nitric acid is 8 M.

6. The purification method according to claim 2, characterized in that, The concentration of the hydrofluoric acid is 0.05-0.1 M.

7. The purification method according to claim 2, characterized in that, The concentration of the hydrofluoric acid is 0.1 M.

8. The purification method according to claim 2, characterized in that, The concentration of the citric acid is 0.4-0.6 M.

9. The purification method according to claim 2, characterized in that, The concentration of the citric acid is 0.5 M.

10. The purification method according to claim 1, characterized in that, The packing material of the cation exchange column includes: AG50W-X8 cation exchange resin or any sulfonated styrene-divinylbenzene copolymer with a crosslinking degree greater than 4.

11. The purification method according to claim 1, characterized in that, The cation exchange column contains cation resin with a particle size of 200-400 mesh.

12. The purification method according to claim 1, characterized in that, In step one, the flow rate during pre-washing and washing is 0.2-0.6 mL / min.

13. The purification method according to claim 1, characterized in that, In step one, the flow rate during pre-washing and washing is 0.5 mL / min.

14. The purification method according to claim 1, characterized in that, The first organic acid is a citric acid solution with a concentration of 0.4-0.6 M; during pre-washing, the amount of the first organic acid used is 3-5 BV; when washing the cation exchange column with the first organic acid, the amount of the first organic acid used is 25-35 BV.

15. The purification method according to claim 1, characterized in that, The first organic acid is a 0.5 M citric acid solution.

16. The purification method according to claim 1, characterized in that, When washing the cation exchange column with a first organic acid, the amount of the first organic acid used is 30 BV.

17. The purification method according to claim 1, characterized in that, The first inorganic acid is a nitric acid solution with a concentration of 1-2 M; when washing the cation exchange column with the first inorganic acid, the amount of the first inorganic acid used is 25-35 BV.

18. The purification method according to claim 1, characterized in that, The first inorganic acid is a nitric acid solution with a concentration of 1.8 M.

19. The purification method according to claim 1, characterized in that, When washing the cation exchange column with the first inorganic acid, the amount of the first inorganic acid used is 30 BV.

20. The purification method according to claim 1, characterized in that, The second inorganic acid is a nitric acid solution with a concentration of 5-7 M; when washing the cation exchange column with the second inorganic acid, the amount of the second inorganic acid used is 15-25 BV.

21. The purification method according to claim 1, characterized in that, The second inorganic acid is a 6 M nitric acid solution.

22. The purification method according to claim 1, characterized in that, When washing the cation exchange column with a second inorganic acid, the amount of the second inorganic acid used is 20 BV.

23. The purification method according to claim 1, characterized in that, In step two, the flow rate during pre-washing and washing is 0.2-0.6 mL / min.

24. The purification method according to claim 1, characterized in that, In step two, the flow rate during pre-washing and washing is 0.5 mL / min.

25. The purification method according to claim 1, characterized in that, In step two, the third inorganic acid is a nitric acid solution with a concentration of 3-5M; during the pre-washing in step two, the amount of the third inorganic acid used is 4-6 BV.

26. The purification method according to claim 1, characterized in that, In step two, the third inorganic acid is a nitric acid solution with a concentration of 4 M.

27. The purification method according to claim 1, characterized in that, In step two, during pre-washing, the amount of the third inorganic acid used is 5 BV.

28. The purification method according to claim 1, characterized in that, In step two, the third inorganic acid is a nitric acid solution with a concentration of 3-5M; when washing the solid-phase extraction column I with the third inorganic acid in step two, the amount of the third inorganic acid used is 20-30 BV.

29. The purification method according to claim 28, characterized in that, In step two, the third inorganic acid is a 4M nitric acid solution.

30. The purification method according to claim 1, characterized in that, In step two, when washing the solid-phase extraction column I with a third inorganic acid, the amount of the third inorganic acid used is 25 BV.

31. The purification method according to claim 1, characterized in that, The fourth inorganic acid is a nitric acid solution with a concentration of 0.008-0.012M; when washing the solid phase extraction column I with the fourth inorganic acid, the amount of the fourth inorganic acid used is 45-55 BV.

32. The purification method according to claim 1, characterized in that, The fourth inorganic acid is a nitric acid solution with a concentration of 0.01 M.

33. The purification method according to claim 1, characterized in that, When washing solid-phase extraction column I with the fourth inorganic acid, the amount of the fourth inorganic acid used is 50 BV.

34. The purification method according to claim 1, characterized in that, In step three, the flow rate during pre-washing and washing is 0.1-0.3 mL / min.

35. The purification method according to claim 1, characterized in that, In step three, the flow rate during pre-washing and washing is 0.2 mL / min.

36. The purification method according to claim 1, characterized in that, In step three, the third inorganic acid is a nitric acid solution with a concentration of 2-4M; during the pre-washing in step three, the amount of the third inorganic acid used is 4-6 BV.

37. The purification method according to claim 1, characterized in that, In step three, the third inorganic acid is a 4 M nitric acid solution.

38. The purification method according to claim 1, characterized in that, In step three, during pre-washing, the amount of the third inorganic acid used is 5 BV.

39. The purification method according to claim 1, characterized in that, In step three, when washing the solid-phase extraction column II with a third inorganic acid, the amount of the third inorganic acid used is 8-12 BV.

40. The purification method according to claim 1, characterized in that, In step three, when washing the solid-phase extraction column II with a third inorganic acid, the amount of the third inorganic acid used is 10 BV.

41. A purification apparatus for use in the purification method of actinium as described in claim 1, characterized in that, include: The first obtaining unit includes a cation exchange column for passing a thorium target solution through and washing with an inorganic acid to obtain a solution containing Ac. 3+ The first effluent; The second obtaining unit includes a TK221 resin extraction column for extracting resin containing Ac. 3+ The first effluent is passed through and washed with an inorganic acid to obtain a solution containing Ac. 3+ The second effluent; The third obtaining unit includes a TRU resin extraction column for extracting substances containing Ac 3+ The second effluent was passed through and washed with inorganic acid to obtain purified actinium product.

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