阅读说明：本技术 一种放射性有机萃取剂废液处理的方法及装置 (Method and device for treating radioactive organic extractant waste liquid ) 是由 武毓勇 翁展 贾惠敏 张惟睿 李鑫 于 2021-07-07 设计创作，主要内容包括：本发明公开一种放射性有机萃取剂废液处理的方法,包括：将放射性有机萃取剂废液进行精馏处理,先分离出核素和重质辐解产物,得到第一混合物和TBP,再分离出第一混合物中的轻质辐解产物,得到煤油。本发明还公开一种放射性有机萃取剂废液处理的系统,包括一级精馏单元、二级精馏单元,所述一级精馏单元,用于分离出放射性有机萃取剂废液中的核素和重质辐解产物,得到第一混合物和TBP；所述二级精馏单元,与所述一级精馏单元相连,用于分离出第一混合物中的轻质辐解产物,得到煤油。本发明可对放射性有机萃取剂废液中的TBP、煤油进行回收,有效减少放射性有机萃取剂废液的体积,极大地减少了放射性有机萃取剂废液的最终处置量,有利于节省成本。(The invention discloses a method for treating radioactive organic extractant waste liquid, which comprises the following steps: rectifying the radioactive organic extractant waste liquid, firstly separating out nuclide and heavy radiolysis products to obtain a first mixture and TBP, and then separating out light radiolysis products in the first mixture to obtain kerosene. The invention also discloses a system for treating the radioactive organic extractant waste liquid, which comprises a primary rectifying unit and a secondary rectifying unit, wherein the primary rectifying unit is used for separating nuclides and heavy radiolysis products in the radioactive organic extractant waste liquid to obtain a first mixture and TBP; and the secondary rectifying unit is connected with the primary rectifying unit and is used for separating the light radiolysis product in the first mixture to obtain the kerosene. The method can recover TBP and kerosene in the radioactive organic extractant waste liquid, effectively reduce the volume of the radioactive organic extractant waste liquid, greatly reduce the final disposal amount of the radioactive organic extractant waste liquid, and is favorable for saving the cost.)

1. The method for treating the radioactive organic extractant waste liquid is characterized in that the organic extractant is tributyl phosphate TBP/kerosene OK, and the treatment method comprises the following steps: rectifying the radioactive organic extractant waste liquid, firstly separating out nuclide and heavy radiolysis products to obtain a first mixture and TBP, and then separating out light radiolysis products in the first mixture to obtain kerosene.

2. The method for treating a radioactive organic extractant waste liquid according to claim 1, which comprises the following steps:

s101, inputting the radioactive organic extractant waste liquid into a first rectifying tower to carry out primary rectification treatment, heating and evaporating the radioactive organic extractant waste liquid in a tower kettle reboiler of the first rectifying tower to enable nuclides and heavy radiolysis products in the radioactive organic extractant waste liquid to be retained in the tower kettle reboiler of the first rectifying tower, distilling first organic steam generated by evaporation through the first rectifying tower and outputting the first organic steam from the tower top of the first rectifying tower, condensing a gas phase output from a gas phase outlet at the tower top of the first rectifying tower to obtain a first condensate, returning the first condensate to the first rectifying tower to be used as reflux liquid to carry out reflux circulation, carrying out mass transfer on the reflux liquid and the first organic steam in the first rectifying tower to reduce the content of TBP in the gas phase, and carrying out multiple circulation until the content of TBP in the first condensate is reduced to a first concentration, taking part of the first condensate as the first mixture, continuously carrying out reflux circulation on the other part of the first condensate, then taking a sample from a downward flowing liquid phase collected by a liquid phase collecting mechanism positioned at a side line extraction outlet in the first rectifying tower when the temperature of the side line extraction outlet in the first rectifying tower is a first temperature, and taking the liquid phase in the liquid phase collecting mechanism through the side line extraction outlet when the content of TBP in the sample reaches a second concentration, wherein the extracted liquid phase is the TBP;

s102, inputting the extracted first mixture into a second rectifying tower for secondary rectification, heating the first mixture by a tower kettle reboiler of the second rectifying tower, evaporating the light radiolysis product in the first mixture and outputting the light radiolysis product from a gas phase outlet at the top of the second rectifying tower, and retaining the kerosene in the tower kettle reboiler of the second rectifying tower.

3. The method as claimed in claim 2, wherein the temperature of the first-stage rectification is 50-160 ℃, the pressure is 200-3000Pa, the reflux ratio is 0.8-4, and the condensation temperature is less than or equal to 20 ℃.

4. The method of claim 2, wherein the first concentration is TBP content ≤ 0.02 wt%;

the first temperature is 80-95 ℃, and the second concentration is that the TBP content is more than or equal to 80 wt%.

5. The method of radioactive organic extractant waste liquid treatment according to claim 2, further comprising:

continuously inputting preheated radioactive organic extractant waste liquid into the first rectifying tower while extracting TBP from the side extraction outlet,

the temperature of the preheated radioactive organic extractant waste liquid is 65-85 ℃.

6. The method for treating the radioactive organic extractant waste liquid according to claim 2, wherein the temperature of the secondary rectification is 70-160 ℃, and the pressure is 5-20 Kpa.

7. A system for treating radioactive organic extractant waste liquid is characterized by comprising a primary rectification unit and a secondary rectification unit,

the primary rectifying unit is used for separating nuclides and heavy radiolysis products in the radioactive organic extractant waste liquid to obtain a first mixture and TBP;

and the secondary rectifying unit is connected with the primary rectifying unit and is used for receiving the first mixture and separating light radiolysis products in the first mixture to obtain the kerosene.

8. The system for radioactive organic extractant waste liquid treatment according to claim 7, wherein the primary rectification unit comprises a first rectification column (4), a first kettle reboiler (5), a first condensation mechanism, a first reflux drum (10),

the first rectifying tower is provided with a feed inlet for introducing radioactive organic extractant waste liquid;

the first tower kettle reboiler is connected with the first rectifying tower and is used for heating the introduced radioactive organic extractant waste liquid to gasify light radiolysis products, kerosene and TBP in the radioactive organic extractant waste liquid;

the first condensing mechanism is connected with a gas phase outlet of the first rectifying tower and is used for condensing a gas phase substance output by the first rectifying tower;

the inlet of the first reflux tank (10) is connected with the first condensing mechanism, the outlet of the first reflux tank is connected with a reflux pipeline of the first rectifying tower, so as to return the first condensate obtained in the first condensing mechanism to the first rectifying tower for reflux,

the first rectifying tower is provided with a side line extraction outlet (25), a liquid phase collecting mechanism (26) is arranged at the side line extraction outlet, the liquid phase collecting mechanism is used for collecting TBP liquid phase substances flowing downwards in the first rectifying tower, and the side line extraction outlet is used for extracting the liquid phase substances in the liquid phase collecting mechanism to obtain the TBP.

9. The system for radioactive organic extractant waste liquid treatment according to claim 8, wherein the first rectification column is a vacuum packed rectification column comprising a first stripping separation zone (41), a defoaming zone (42), and a first rectification separation zone (43),

the first stripping separation zone, the defoaming zone and the first rectification separation zone are sequentially distributed from bottom to top,

the separation stage number of the first stripping separation zone is 3-15, the separation stage number of the defoaming zone is 3-10, and the separation stage number of the first rectifying separation zone is 5-15.

10. The radioactive organic extractant waste liquid treatment system according to claim 8, further comprising a preheater (3),

the preheater is connected with the first rectifying tower and used for preheating the radioactive organic waste liquid before the radioactive organic waste liquid is input into the first rectifying tower.

11. The system for radioactive organic extractant waste liquid treatment according to claim 8, characterized in that the secondary rectification unit comprises a second rectification column (17), a second kettle reboiler (18), a second condensation mechanism, and a second reflux drum (22),

the second rectifying tower is connected with the first reflux tank (10) so as to introduce first condensate as the first mixture;

the second kettle reboiler is connected with the second rectifying tower and is used for heating the introduced first mixture to gasify the light radiolysis products and retain the kerosene in the second kettle reboiler;

the second condensing mechanism is connected with a gas phase outlet of the second rectifying tower and is used for condensing the gas phase substances output by the second rectifying tower;

and the inlet of the second reflux tank (22) is connected with the second condensing mechanism, and the outlet of the second reflux tank is connected with a reflux pipeline of the second rectifying tower, so that the second condensate obtained in the second condensing mechanism is returned to the second rectifying tower.

12. The system for radioactive organic extractant waste liquid treatment according to claim 11, wherein the second rectification column is a vacuum packed rectification column comprising a second stripping separation zone (171), a second rectification separation zone (172),

the second stripping separation area and the second rectification separation area are sequentially distributed from bottom to top,

the separation stage number of the second stripping separation zone is 5-15, and the separation stage number of the second rectification separation zone is 3-8.

Technical Field

The invention belongs to the technical field of nuclear, and particularly relates to a method and a device for treating radioactive organic extractant waste liquid.

Background

Because tributyl phosphate (TBP) has obvious extraction difference on uranium, plutonium and fission products, and kerosene (OK) can be used as a diluent to reduce the density and viscosity of a system, 30% TBP/OK is often selected as an extractant in the Purex process (the Prikes nuclear fuel post-processing process) of the nuclear fuel post-processing industry. In the extraction process, under the actions of radiolysis, hydrolysis in an acidic environment and the like, a 30% TBP/OK extracting agent can be degraded to generate various degradation products, so that the performance of the extracting agent is deteriorated, the extraction process is damaged, the decontamination factor is reduced, the retention amount of uranium and plutonium in waste liquid is increased, and the emulsion phenomenon is generated to cause phase splitting difficulty, so that the mass transfer is deteriorated, and even the operation cannot be carried out.

Wherein, the degradation products of 30 percent TBP/OK in the extraction process mainly comprise primary products generated by hydrolysis and degradation of TBP such as dibutyl phosphate (DBP), monobutyl phosphate (MBP), phosphoric acid, butyl nitrate and the like; primary products produced by the radiolysis of kerosene such as carboxylic acids, organic nitrates, nitrites, nitro compounds, hydroximic acids, and the like; and a series of heavy radiolysis products are formed by the mutual polymerization of the primary products and the complexation of fission products.

At present, the extractant for engineering treatment of the deterioration is generally regenerated by alkali washing. Although the alkaline washing regeneration method has a good effect of removing DBP, MBP and other acidic radiolysis products, the heavy radiolysis products mainly comprise a series of long-chain acid phosphate, acid tributyl diphosphate and long-chain alkyl neutral phosphate which are formed by combining alkyl and TBP, the substances have obvious polarity, strong interface activation and obvious retention on metal products, and the alkaline washing regeneration method has poor effect on neutral radiolysis products and heavy radiolysis products because the alkyl chain length is very long and the solubility in an organic phase is very high, the alkaline washing regeneration method cannot be removed in alkaline washing and gradually accumulates in the organic phase, so that the alkaline washing regeneration method needs to be updated after 30% of TBP/OK extractant is used for a period of time, the operation cost is increased, a large amount of radioactive organic extractant waste liquid is generated, and most of the radioactive organic extractant waste liquid is TBP and kerosene, the radionuclide and radiolysis products only account for a very small part, and if the radioactive nuclide and radiolysis products are directly disposed, the disposal amount is large, the disposal cost is high, and the resource waste is caused.

Disclosure of Invention

The technical problem to be solved by the present invention is to provide a method and an apparatus for treating a radioactive organic extractant waste liquid, which can recover TBP and kerosene in the radioactive organic extractant waste liquid, effectively reduce the volume of the radioactive organic extractant waste liquid, greatly reduce the final disposal amount of the radioactive organic extractant waste liquid, and contribute to cost saving.

According to one aspect of the invention, a method for treating radioactive organic extractant waste liquid is provided, which adopts the following technical scheme:

a method for treating radioactive organic extractant waste liquid is disclosed, the organic extractant is tributyl phosphate TBP/kerosene OK, the treatment method comprises: rectifying the radioactive organic extractant waste liquid, firstly separating out nuclide and heavy radiolysis products to obtain a first mixture and TBP, and then separating out light radiolysis products in the first mixture to obtain kerosene.

Preferably, the method specifically comprises the following steps:

s101, inputting the radioactive organic extractant waste liquid into a first rectifying tower to carry out primary rectification treatment, heating and evaporating the radioactive organic extractant waste liquid in a tower kettle reboiler of the first rectifying tower to enable nuclides and heavy radiolysis products in the radioactive organic extractant waste liquid to be retained in the tower kettle reboiler of the first rectifying tower, distilling first organic steam generated by evaporation through the first rectifying tower and outputting the first organic steam from the tower top of the first rectifying tower, condensing a gas phase output from a gas phase outlet at the tower top of the first rectifying tower to obtain a first condensate, returning the first condensate to the first rectifying tower to be used as reflux liquid to carry out reflux circulation, carrying out mass transfer on the reflux liquid and the first organic steam in the first rectifying tower to reduce the content of TBP in the gas phase, and carrying out multiple circulation until the content of TBP in the first condensate is reduced to a first concentration, taking part of the first condensate as the first mixture, continuously carrying out reflux circulation on the other part of the first condensate, then taking a sample from a downward flowing liquid phase collected by a liquid phase collecting mechanism positioned at a side line extraction outlet in the first rectifying tower when the temperature of the side line extraction outlet in the first rectifying tower is a first temperature, and taking the liquid phase in the liquid phase collecting mechanism through the side line extraction outlet when the content of TBP in the sample reaches a second concentration, wherein the extracted liquid phase is the TBP;

s102, inputting the extracted first mixture into a second rectifying tower for secondary rectification, heating the first mixture by a tower kettle reboiler of the second rectifying tower, evaporating the light radiolysis product in the first mixture and outputting the light radiolysis product from a gas phase outlet at the top of the second rectifying tower, and retaining the kerosene in the tower kettle reboiler of the second rectifying tower.

Preferably, the temperature of the first-stage rectification treatment is 50-160 ℃, the pressure is 200-3000Pa, the reflux ratio is 0.8-4, and the condensation temperature is less than or equal to 20 ℃.

Preferably, the first concentration is TBP content less than or equal to 0.02 wt%; the first temperature is 80-95 ℃, and the second concentration is that the TBP content is more than or equal to 80 wt%.

Preferably, the method further comprises:

and continuously inputting the preheated radioactive organic extractant waste liquid into the first rectifying tower while extracting TBP from the side draw outlet, wherein the temperature of the preheated radioactive organic extractant waste liquid is 65-85 ℃.

Preferably, the temperature of the secondary rectification treatment is 70-160 ℃, and the pressure is 5-20 Kpa.

According to another aspect of the present invention, a system for treating a radioactive organic extractant waste liquid is provided, which comprises the following technical scheme:

a system for radioactive organic extractant waste liquid treatment comprises a primary rectification unit and a secondary rectification unit, wherein:

the primary rectifying unit is used for separating nuclides and heavy radiolysis products in the radioactive organic extractant waste liquid to obtain a first mixture and TBP;

and the secondary rectifying unit is connected with the primary rectifying unit and is used for receiving the first mixture and separating light radiolysis products in the first mixture to obtain the kerosene.

Preferably, the primary rectification unit comprises a first rectification column, a first kettle reboiler, a first condensing mechanism and a first reflux tank, wherein:

the first rectifying tower is provided with a feed inlet for introducing radioactive organic extractant waste liquid;

the first tower kettle reboiler is connected with the first rectifying tower and is used for heating the introduced radioactive organic extractant waste liquid to gasify light radiolysis products, kerosene and TBP in the radioactive organic extractant waste liquid;

the first condensing mechanism is connected with a gas phase outlet of the first rectifying tower and is used for condensing a gas phase substance output by the first rectifying tower;

the inlet of the first reflux tank is connected with the first condensing mechanism, and the outlet of the first reflux tank is connected with a reflux pipeline of the first rectifying tower so as to return the first condensate obtained in the first condensing mechanism to the first rectifying tower for reflux;

the first rectifying tower is provided with a side line extraction outlet, a liquid phase collecting mechanism is arranged at the side line extraction outlet and used for collecting liquid phase substances flowing downwards in the first rectifying tower, and the side line extraction outlet is used for extracting the liquid phase substances in the liquid phase collecting mechanism to obtain TBP.

Preferably, the first distillation column is a vacuum packed distillation column comprising a first stripping separation zone, a defoaming zone, and a first distillation separation zone, wherein:

the first stripping separation zone, the defoaming zone and the first rectification separation zone are sequentially distributed from bottom to top;

the separation stage number of the first stripping separation zone is 3-15, the separation stage number of the defoaming zone is 3-10, and the separation stage number of the first rectifying separation zone is 5-15.

Preferably, the system further comprises a preheater connected to the first rectification column for preheating the radioactive organic waste liquid before it is input to the first rectification column.

Preferably, the secondary rectification unit comprises a second rectification column, a second kettle reboiler, a second condensing mechanism, and a second reflux drum, wherein:

the second rectifying tower is connected with the first reflux tank, so that first condensate is introduced to serve as the first mixture;

the second tower kettle reboiler is connected with the second rectifying tower and used for heating the introduced first mixture to gasify light radiolysis products in the first mixture, and the second tower kettle reboiler traps medium kerosene in the second tower kettle reboiler;

the second condensing mechanism is connected with a gas phase outlet of the second rectifying tower and is used for condensing the gas phase substances output by the second rectifying tower;

and the inlet of the second reflux tank is connected with the second condensing mechanism, and the outlet of the second reflux tank is connected with a reflux pipeline of the second rectifying tower so as to return the second condensate obtained in the second condensing mechanism to the second rectifying tower.

Preferably, the second distillation column is a vacuum packing distillation column, which comprises a second stripping separation zone and a second distillation separation zone, wherein:

the second stripping separation zone and the second rectification separation zone are sequentially distributed from bottom to top;

the separation stage number of the second stripping separation zone is 5-15, and the separation stage number of the second rectification separation zone is 3-8.

The method and the system for treating the radioactive organic extractant waste liquid can recover TBP and kerosene in the radioactive organic extractant waste liquid, thereby effectively reducing the volume of the radioactive organic extractant waste liquid, greatly reducing the final treatment amount of the radioactive organic extractant waste liquid, realizing volume reduction (the volume reduction ratio can reach 100:1), reducing the treatment difficulty and saving the treatment cost. And the recovered TBP and kerosene can be returned to the nuclear fuel post-treatment plant for reuse, so that the operation cost of the nuclear fuel post-treatment plant can be saved.

Drawings

FIG. 1 is a schematic structural diagram of a radioactive organic extractant waste liquid treatment system in an embodiment of the invention;

fig. 2 is a schematic view of the installation of a liquid phase collecting device according to an embodiment of the present invention.

In the figure: 1-a feeding tank; 2-a feed pump; 3-a preheater; 4-a first rectification column; 41-first stripping separation zone; 42-a defoaming zone; 43-first rectification separation zone; 5-a first column kettle reboiler; 6-a first residue tank; 7-a first condenser; 8-a second condenser; 9-a first trap; 10-a first reflux drum; 11-a first reflux pump; 12-a third condenser; 13-a TBP receiving tank; 15-a middle distillate receiver tank; 16-a feed pump; 17-a second rectification column; 171-a second stripping and separation zone; 172-a second rectification separation zone; 18-a second column reboiler; 19-a kerosene receiving tank; 20-a fourth condenser; 21-a second trap; 22-a second reflux drum; 23-a second reflux pump; 24-a second residue tank; a1 — second sample port; a2 — first sample port; a3 — third sample port; 25-a side draw; 26-liquid phase collection mechanism.

Detailed Description

The technical solutions in the present invention will be described clearly and completely with reference to the accompanying drawings, and it is obvious that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the scope of the present invention.

In the description of the present invention, it should be noted that the indication of orientation or positional relationship, such as "on" or the like, is based on the orientation or positional relationship shown in the drawings, and is only for convenience and simplicity of description, and does not indicate or imply that the device or element referred to must be provided with a specific orientation, constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention.

In the description of the present invention, the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implying any number of technical features indicated. Thus, features defined as "first", "second", may explicitly or implicitly include one or more of the described features. In the description of the present invention, "a plurality" means two or more unless specifically defined otherwise.

In the description of the present invention, it is to be noted that, unless otherwise explicitly specified or limited, the terms "connected," "disposed," "mounted," "fixed," and the like are to be construed broadly, e.g., as being fixedly or removably connected, or integrally connected; either directly or indirectly through intervening media, or through the interconnection of two elements. The specific meaning of the above terms in the present invention can be understood in specific cases for those skilled in the art.

Example 1

As shown in FIG. 1, this example discloses a method for treating waste liquid of radioactive organic extractant, which is tributyl phosphate (TBP)/kerosene (OK) in the place

The method comprises the following steps:

rectifying the radioactive organic waste liquid, firstly separating out nuclide (such as Y-90, Sr-90, Ni-63, Pu-239, U-235 and the like) and heavy radiolysis product (such as dodecyl phosphate) to obtain a first mixture and tributyl phosphate (TBP), and then separating out light radiolysis product (such as nitrate, nitrite, hydroximic acid and the like) in the first mixture to Obtain Kerosene (OK).

The embodiment also discloses a system for treating the radioactive organic extractant waste liquid, which comprises a primary rectification unit and a secondary rectification unit, wherein:

the primary rectifying unit is used for separating nuclides and heavy radiolysis products in the radioactive organic extractant waste liquid to obtain a first mixture and TBP;

and the secondary rectifying unit is connected with the primary rectifying unit and is used for separating the light radiolysis product in the first mixture to obtain the kerosene.

The method and the system for treating the radioactive organic extractant waste liquid can recover TBP and kerosene in the radioactive organic extractant waste liquid, effectively reduce the volume of the radioactive organic extractant waste liquid, greatly reduce the final disposal amount of the radioactive organic extractant waste liquid, and are favorable for saving the cost.

Example 2

This embodiment discloses a method for treating a radioactive organic extractant waste liquid, as shown in fig. 1, including:

s101, inputting the radioactive organic extractant waste liquid into a first rectifying tower 4 for primary rectifying treatment, separating nuclide and heavy radiolysis products to obtain a first mixture and TBP, wherein the radioactive organic extractant waste liquid is input into the first rectifying tower 4 for primary rectifying treatment, the radioactive organic extractant waste liquid is heated in a tower kettle reboiler of the first rectifying tower 4 to generate evaporation, the nuclide and the heavy radiolysis products in the radioactive organic extractant waste liquid are retained in the tower kettle reboiler of the first rectifying tower 4, first organic steam generated by the evaporation is output from the top of the first rectifying tower 4 after the distillation treatment of the first rectifying tower 4, a gas phase output from a gas phase outlet at the top of the first rectifying tower is condensed to obtain a first condensate, and the first condensate is returned to the first rectifying tower 4 to be used as a reflux liquid for reflux circulation, mass transfer is carried out between the reflux liquid and the first organic steam in the first rectifying tower 4 to reduce the content of TBP in the gas phase, after multiple cycles until the content of TBP in the first condensate is reduced to a first concentration, a part of the first condensate is extracted as a first mixed product, the other part of the first condensate is continuously subjected to reflux circulation, then when the temperature at a lateral extraction outlet 25 in the first rectifying tower is the first temperature, a sample is extracted from the liquid phase which flows downwards and is collected by a liquid phase collecting mechanism 26 at the lateral extraction outlet 25 in the first rectifying tower, when the content of TBP in the sample reaches a second concentration, the liquid phase collected in the liquid phase collecting mechanism 26 is extracted through the lateral extraction outlet 25, and at the moment, the extracted liquid phase is the TBP.

Specifically, the first reboiler 5 is connected to the column bottom of the first rectification column 4, the temperature of the first-stage rectification is 50-160 ℃, more precisely, the operation temperature of the top of the first rectification column is 50-70 ℃, the operation temperature of the bottom of the first rectification column 4 is 130-160 ℃, and the pressure of the first rectification column is 200-3000 Pa. After the radioactive organic extractant waste liquid is input into the first rectifying tower 4, the radioactive organic extractant waste liquid enters the first reboiler 5 from a liquid phase outlet at the tower bottom of the first rectifying tower 4, after the liquid level in the first reboiler 5 reaches a preset height (for example, the liquid level is higher than 0.5-1m of a heating pipe of the first reboiler 5), the radioactive organic extractant waste liquid is stopped to be input into the first rectifying tower 4, the first reboiler 5 is heated, the temperature of the first reboiler 5 is controlled to be 160 ℃, at the moment, light radiolysis products (such as nitrate, nitrite, hydroximic acid and the like), kerosene and TBP in the radioactive organic extractant waste liquid are heated to be changed into first organic steam, nuclides (such as Y-90, Sr-90, Ni-63, Pu-239, U-235 and the like) and heavy radiolysis products (such as dodecyl phosphate) are left in the first reboiler, thereby separating out nuclides and heavy radiolysis products. In this embodiment, the first reboiler 5 is preferably heated with steam at a temperature of 145 ℃ or higher.

The first organic vapor is conveyed to the first rectifying tower 4 through the gas phase outlet of the first reboiler 5, flows upwards, and sequentially passes through the first stripping and separating area 41, the defoaming area 42 and the first rectifying and separating area 43 of the first rectifying tower 4, and the first organic vapor and the liquid phase (mainly derived from the first condensate of the reflux) flowing downwards in the first rectifying tower 4 can generate mass transfer in the ascending process, so that the TBP in the first organic vapor is gradually transferred to the liquid phase flowing downwards, and the kerosene and light radiolysis products in the liquid phase are gradually transferred to the gas phase flowing upwards, so that the content of the TBP in the gas phase output from the top of the first rectifying tower 4 is gradually reduced, and the content of the TBP in the liquid phase flowing downwards in the first rectifying tower 4 is gradually increased, thereby realizing TBP separation. The gas phase in the first rectifying tower 4 is output to a first condensing mechanism from a gas phase outlet at the top of the first rectifying tower 4 for condensation to obtain a first condensate (mainly a mixture of light radiolysis products and kerosene), the remaining non-condensable gas is separated from liquid drops carried in the non-condensable gas through a first catcher 9 and then discharged, and the separated liquid drops are input into a first reflux tank 10. In the embodiment, the condensation temperature of the first condensation mechanism is preferably less than or equal to 20 ℃.

The first condensate obtained by condensation in the first condensation mechanism is firstly conveyed to the first reflux tank 10, after the liquid level in the first reflux tank 10 meets the requirement, for example, the liquid level reaches 1/2-2/3 (when the rectification processing operation starts, the reflux amount is equal to the amount of the first condensate generated by the first condensation mechanism by adjusting the first reflux pump 11, the liquid level adjusting space is large, and the liquid level adjusting space can be adjusted up and down), and then a part of the first condensate is conveyed back to the first rectification tower 4 for reflux circulation. When the reflux circulation is just started, the amount of the first condensate (namely the reflux amount) conveyed to the first rectifying tower 4 is not too large, the liquid level in the first reflux tank 10 is kept basically stable and unchanged, the TBP content in the first condensate is detected at intervals, when the TBP content is more than 0.02 wt%, the reflux amount is increased to continue the reflux circulation, and the TBP content in the gas phase which flows upwards and is discharged is gradually reduced due to the mass transfer process of the refluxed first condensate and the gas phase which flows upwards, so that the TBP content in the first condensate is also gradually reduced, and when the TBP content is reduced to be less than or equal to 0.02 wt%, the TBP content in the first condensate is selected according to a set proportion (related to material balance, particularly according to the calculation result of material balance), wherein the calculation formula is that the amount of the first mixture extracted is equal to the total amount of the radioactive organic extraction waste liquid which is introduced, the amount of extracted TBP-the amount of heavy radioactive organic extraction waste liquid-the amount of extracted heavy radioactive extraction material The condensate is output as the first mixture, that is, the first concentration is a TBP content of 0.02 wt% or less. In this embodiment, oneReflux ratio of the fractional rectification treatment (i.e. the flow L of the first condensate returning to the first rectification column 4)₁With the flow rate D of the first mixture output to the middle distillate receiver tank 15₁Ratio of (i.e. R)₁＝L₁/D₁) Preferably 0.8-4.0.

Meanwhile, mass transfer occurs in the rectification process, so that the concentrations of TBP in liquid phase substances at different heights in the first rectification tower 4 are different, and the temperatures at different heights in the first rectification tower 4 are also different, the method can roughly judge the concentration of TBP in the liquid phase substance at the position by monitoring the temperature at the side draw-out port 25 of the first rectification tower 4, when the temperature at the side draw-out port 25 of the first rectification tower 4 reaches 80-95 ℃ (the temperature at the position is related to the concentration of TBP, the temperature at the position can be roughly judged according to the required concentration in the actual process, for example, when the concentration of TBP required to be extracted is more than 70%, the temperature at the side draw-out port 25 is about 90 ℃), a valve of the side draw-out port 25 is opened, and the liquid phase substance flowing downwards and collected by the liquid phase acquisition mechanism 26 arranged at the position is extracted for side sampling analysis. When the TBP content in the side-sampling sample is lower than the concentration (such as less than 80 wt%) required by the process, closing a valve of the side-sampling outlet 25, continuing the reflux circulation (excessive liquid phase overflows and continues to flow downwards after the liquid phase collecting mechanism is full of liquid phase), and performing side-sampling analysis again at intervals until the TBP content in the side-sampling sample reaches the concentration (such as more than or equal to 80 wt%) required by the process, and starting to extract TBP through the side-sampling outlet 25 according to a preset proportion (specifically related to the concentration required by the process, wherein the higher the concentration is, the smaller the extraction proportion is), so as to obtain a TBP recovery. That is, the first temperature is 80-95 deg.C, and the second concentration is TBP content greater than or equal to 80 wt%. In this embodiment, the purification coefficient (i.e. the ratio of the radioactive concentration before the treatment to the radioactive concentration after the treatment) of the primary distillation treatment can reach 200-.

In some embodiments, the method further comprises:

while the side draw 25 draws TBP, preheated radioactive organic extractant waste liquid may be continuously fed to the first rectification column 4. That is, the feeding mode of the radioactive organic extractant waste liquid in the method can be the intermittent feeding mode or the continuous feeding mode, and the continuous feeding mode is adopted, so that the continuous treatment is favorably realized, and the treatment efficiency is improved.

Specifically, the radioactive organic extractant waste liquid is fed into the preheater 3 for preheating before being additionally conveyed to the first rectifying tower 4, and the temperature of the preheated radioactive organic extractant waste liquid is preferably 65-85 ℃. Of course, when the step 101 is performed, the radioactive organic extractant waste liquid to be introduced may be preheated. The input flow of the preheated radioactive organic extractant waste liquid is equal to the total flow of the materials output by the first rectifying tower 4, namely the input amount of the preheated radioactive organic extractant waste liquid is equal to the sum of the output amount of the first reflux tank 10 (namely the amount of the extracted first mixture), the side line output amount (namely the amount of the extracted TBP) and the tower kettle output amount of the first rectifying tower 4 (namely the amount of nuclide and heavy radiolysis products), wherein the amount of the first mixture, the TBP, the nuclide and the heavy radiolysis products can adopt a continuous extraction mode or an intermittent extraction mode on the premise of meeting the process requirements.

S102, inputting the extracted first mixture into the second rectifying tower 17 for secondary rectification, heating the first mixture by a tower kettle reboiler of the second rectifying tower 17, evaporating light radiolysis products (such as nitrate, nitrite, hydroximic acid and the like) in the first mixture, and outputting the light radiolysis products from a gas phase outlet at the top of the second rectifying tower 17, so that the kerosene is retained in the tower kettle reboiler of the second rectifying tower 17.

Specifically, a second reboiler 18 is connected to the bottom of the second rectifying column 17, and the temperature of the second-stage rectification treatment is preferably 50 to 160 ℃ and the pressure (absolute pressure) is preferably 5 to 20 kPa. After the condensate (first mixture) extracted from the first reflux tank 10 is input into the second rectifying tower 17, the condensate enters the second reboiler 18 from the liquid phase outlet at the tower bottom, after the liquid level in the second reboiler 18 reaches a predetermined height (for example, the liquid level is 0.5-1m higher than the heating pipe of the second reboiler 18), the input of the first mixture into the second rectifying tower 17 is stopped, and the second reboiler 18 is heated, so that the temperature of the second reboiler 18 is controlled at 140 ℃ and 160 ℃, at this time, the light radiolysis products in the first mixture are heated to become the second organic vapor due to the difference in pressure from the first rectifying column, and kerosene is left in the second reboiler 18, and then sent to the kerosene receiving tank 19, the kerosene recovery is realized, and the TBP content in the kerosene of the kerosene receiving tank is less than or equal to 0.02 wt% through detection, and the purification coefficient of the secondary rectification treatment can reach 1000-10000. In this embodiment, the second reboiler 18 is heated by steam, preferably at a temperature of 145 ℃ or higher.

The second organic vapor is delivered to the second rectifying tower 17 through the gas phase outlet of the second reboiler 18, flows upward, and sequentially passes through the stripping separation zone 171 and the second rectifying separation zone 172 of the second rectifying tower 17, and the second organic vapor and the liquid phase material (mainly from the second condensate of the reflux) flowing downward in the second rectifying tower 17 undergo mass transfer in the ascending process, so that the kerosene in the second organic vapor is gradually transferred into the liquid phase material flowing downward, and the light radiolysis products in the liquid phase material are gradually transferred into the gas phase material flowing upward, so that the kerosene content in the gas phase material output from the top of the second rectifying tower 17 is gradually reduced, and the kerosene content in the liquid phase material flowing downward in the second rectifying tower 17 is gradually increased, thereby achieving kerosene separation. The gas phase in the second rectifying tower 17 is output from the gas phase outlet at the top of the second rectifying tower 17 to a second condensing mechanism for condensation to obtain a second condensate (mainly light radiolysis products), the remaining non-condensable gas is separated from liquid drops carried in the non-condensable gas by a second catcher 21 and then is discharged, and the separated liquid drops are input into a second reflux tank 22. In the embodiment, the condensation temperature of the second condensation mechanism is preferably less than or equal to 20 ℃.

The second condensate condensed in the second condensing mechanism is firstly conveyed to the second reflux tank 22, and after the liquid level in the second reflux tank 22 meets the requirement, for example, the liquid level reaches 1/2-2/3, a part of the second condensate is conveyed back to the second rectifying tower 17 for reflux circulation. When the reflux circulation is started, the reaction mixture is sent to the second rectifying tower 17The amount of the second condensate in the second reflux tank 22 is not too large, the liquid level in the second reflux tank 22 is kept basically stable and unchanged, the kerosene composition in the second condensate is detected at intervals, when long carbon chain kerosene (such as C12, C13 and C14) is contained in the second condensate, the reflux amount is increased to continue reflux circulation, and when the long carbon chain kerosene (such as C10 and C11) and light radiolysis products are mainly contained in the second condensate, the second condensate in the second reflux tank 22 is output according to a set proportion (related to material balance, and can be selected according to the calculation result of material balance), namely the light radiolysis products. In this embodiment, the reflux ratio of the second rectification (i.e., the second condensate flow rate L returned to the second rectification column 17)₂And a second condensate flow rate D to a second residue tank 24₂Ratio of (i.e. R)₂＝L₂/D₂) Preferably 30-100.

The radioactive organic extractant waste liquid in the present embodiment mainly refers to a mixed organic waste liquid containing waste tributyl phosphate (TBP) and kerosene generated in a nuclear fuel reprocessing plant, but may be a mixed organic waste liquid containing waste tributyl phosphate (TBP) and kerosene generated in another place.

The method for treating the radioactive organic extractant waste liquid is particularly suitable for treating the radioactive organic extractant waste liquid in a nuclear fuel post-treatment plant, not only can recover TBP and kerosene in the radioactive organic extractant waste liquid, but also can return the recovered TBP and kerosene to the nuclear fuel post-treatment plant for reuse, so that the operation cost of the nuclear fuel post-treatment plant can be saved; the volume of the radioactive organic extractant waste liquid can be effectively reduced (the volume reduction ratio can reach 100:1), the final treatment amount of the radioactive organic extractant waste liquid is greatly reduced, the treatment difficulty can be reduced, and the treatment cost can be saved.

Example 3

As shown in fig. 1, the present embodiment discloses a system for treating a radioactive organic extractant waste liquid, which comprises a primary rectification unit and a secondary rectification unit, wherein: the primary rectification unit is used for separating nuclides and heavy radiolysis products in the radioactive organic extractant waste liquid to obtain a first mixture and TBP; the second-stage rectifying unit is connected with the first-stage rectifying unit and used for receiving the first mixture and separating light radiolysis products in the first mixture to obtain the kerosene.

In this embodiment, the first-stage rectification unit includes a first rectification tower 4, a first reboiler 5, a first condensing mechanism, and a first reflux tank 10, wherein:

the first rectifying tower 4 is provided with a feed inlet for introducing radioactive organic extractant waste liquid; the first reboiler 5 is connected with the first rectifying tower 4 and is used for heating the introduced radioactive organic extractant waste liquid to ensure that light radiolysis products (such as nitrate, nitrite, hydroximic acid, olefin, carboxylic acid and the like), kerosene and gasified TBP in the radioactive organic extractant waste liquid; the first condensing mechanism is connected with a gas phase outlet at the top of the first rectifying tower 4 and is used for condensing gas phase substances output by the first rectifying tower 4; an inlet of the first reflux drum 10 is connected to the first condensing mechanism, an outlet thereof is connected to a reflux line of the first rectifying column 4 to return the first condensate obtained in the first condensing mechanism to the first rectifying column 4 for reflux, and the first reflux drum 10 is connected to the middle distillate receiving drum 15; the first rectifying tower 4 is provided with a side draw outlet 25, and a liquid phase collecting mechanism 26 (shown in fig. 2) is arranged at the position of the side draw outlet 25, the liquid phase collecting mechanism 26 is used for collecting the liquid phase material flowing downwards in the first rectifying tower, and the side draw outlet 25 is used for drawing the liquid phase material in the liquid phase collecting mechanism 26 to obtain the TBP.

Specifically, the first rectification column 4 is preferably a vacuum packing rectification column, which includes a first stripping separation region 41, a defoaming region 42, and a first rectification separation region 43, the first stripping separation region 41, the defoaming region 42, and the first rectification separation region 43 are sequentially distributed from bottom to top, each region is connected by a flange, each region is divided into a plurality of separation stages, wherein the separation stages (herein, theoretical stages) of the first stripping separation region 41 are preferably 3 to 15, the separation stages of the defoaming region 42 are preferably 3 to 10, and the separation stages of the first rectification separation region 43 are preferably 5 to 15. The feed liquid inlet of the first reboiler 5 is connected with the liquid phase outlet of the tower bottom of the first rectifying tower 4, and is used for heating the liquid phase output from the first rectifying tower 4, so that the light radiolysis products, kerosene and TBP in the liquid phase are heated to be changed into gas phase (namely first organic steam), and the nuclide and heavy radiolysis products (such as dodecyl phosphate) in the liquid phase are intercepted in the first reboiler 5 and then extracted and conveyed to a first residue tank 6 connected with the liquid phase outlet of the first reboiler 5. The gas phase outlet of the first reboiler 5 is connected to a position below the first stripping and separating area 41 of the first rectifying tower 4, and is used for returning the first organic vapor generated by heating in the first reboiler 5 to the first rectifying tower 4, the first organic vapor flows upwards and passes through the first stripping and separating area 41, the defoaming area 42, and the first rectifying and separating area 43 in sequence, the first organic vapor can generate mass transfer with the liquid phase (mainly the first condensate liquid from the reflux) flowing downwards in the first rectifying tower 4 in the ascending process, so that the substance with higher boiling point in the first organic vapor gradually transfers to the liquid phase flowing downwards, the substance with lower boiling point in the liquid phase gradually transfers to the first organic vapor flowing upwards, wherein, when the first organic vapor passes through the first stripping and separating area 41, the first organic vapor can generate mass transfer with the liquid phase (mainly the first condensate liquid from the reflux) flowing downwards, so that the low-boiling substances (such as kerosene) in the liquid phase flowing downwards are transferred into the ascending first organic vapor, and simultaneously, the substances with higher boiling points in the first organic vapor are preferentially transferred into the liquid phase flowing downwards; while the first organic vapor continues to flow upward to pass through the defoaming region 42, droplets entrained in the first organic vapor are trapped and defoamed, and meanwhile, the first organic vapor can perform mass transfer with the liquid phase which continues to flow downward, so that heavy radiolysis products and radionuclides entrained in the first organic vapor are transferred to the liquid phase which flows downward, and thus the heavy radiolysis products and radionuclides entrained in the first organic vapor can be removed; when the first organic vapor continues to flow upward to pass through the first rectification separation zone 43, the first organic vapor will undergo mass transfer with the liquid phase which continues to flow downward, so that the high boiling point substances (such as TBP) in the first organic vapor are transferred to the liquid phase which continues to flow downward, thereby gradually realizing TBP separation, and the remaining first organic vapor is output from the gas phase outlet at the top of the first rectification column 4 to the first condensation mechanism. The first condensing means comprise one or more, preferably two, first condensers 7, the second condenser 8, the first condenser 7 and the second condenser 8 are arranged in series, a gas phase substance output from a gas phase outlet of the first rectifying tower 4 is firstly input into the first condenser 7 to be condensed, condensate obtained from the first condenser 7 is conveyed to the first reflux tank 10, non-condensable gas in the first condenser 7 is input into the second condenser 8 to be condensed again, condensate obtained from the second condenser 8 is conveyed into the first reflux tank 10, non-condensable gas in the second condenser 8 is input into the first catcher 9 to be subjected to gas-liquid separation, liquid drops separated from the first catcher 9 are conveyed into the first reflux tank 10 through a liquid phase outlet of the first catcher 9, and gas separated from the first catcher 9 is discharged into a vacuum system through a gas phase outlet of the first catcher 9 to be subjected to subsequent treatment. The first reflux drum 10 is connected to the upper part of the first rectifying tower 4, preferably to the upper position of the first rectifying and separating section 43, by a first reflux pump 11. A first sampling port a2 is provided on the outlet of the first reflux drum 10 to sample and analyze the condensate (first condensate) output from the first reflux drum 10. The side draw port 25 is disposed above the defoaming zone 42, preferably between the defoaming zone 42 and the first rectifying and separating zone 43, and can be selected according to the concentration of the desired TBP to be drawn. As shown in fig. 2, the liquid phase collecting mechanism 26 is disposed at the side draw outlet 25 and downward along the inner sidewall of the first rectifying tower 4, so as to collect the downward flowing liquid phase separated from the rectifying separation zone 43 to the liquid phase collecting mechanism 26 and form a certain liquid level height, so as to be drawn through the side draw outlet 25 (before the TBP and the first mixture are drawn, the first rectifying tower 4 is in a full reflux state, the liquid phase overflows after filling the liquid phase collecting mechanism 26 and continues to flow downward, the high boiling point substance is transferred from the ascending gas phase (the first organic vapor) to the descending liquid phase (the first condensate refluxed to the first rectifying tower 4), and the low boiling point substance is transferred from the descending liquid phase to the ascending gas phase). A side draw-out pipeline is connected to the side draw-out port 25 and comprises a third condenser 12 and a TBP receiving tank 13, the material (TBP) drawn out from the side draw-out port 25 is conveyed into the third condenser 12 for condensation, and the obtained TBP condensate is conveyed into the TBP receiving tank 13. And a second sampling port A1 is arranged on the side line extraction pipeline and is used for sampling and analyzing samples from the side line extraction port 25.

In this embodiment, the first condenser 7, the second condenser 8, and the third condenser 12 preferably adopt a shell-and-tube structure, and all adopt chilled water as a condensing medium, and the temperature of the chilled water is preferably no greater than 20 ℃.

In this embodiment, the system further comprises a preheater 3, and the preheater 3 is connected to the first distillation column 4 and is used for preheating the radioactive organic extractant waste liquid before inputting the radioactive organic extractant waste liquid into the first distillation column 4.

Specifically, the radioactive organic extractant waste liquid is stored in the feed tank 1, the feed tank 1 is connected with the preheater 3 through the feed pump 2, and the preheater 3 is connected with the feed inlet of the first rectifying tower 4. In this embodiment, the feed inlet of the first distillation column 4 is preferably provided at a position between the first stripping and separating section 41 and the demister section 42 of the first distillation column 4, and the preheating temperature of the preheater 3 is 65 to 85 ℃.

In this embodiment, the secondary rectification unit includes a second rectification tower 17, a second reboiler 18, a second condensation mechanism, and a second reflux tank 22, the second rectification tower 17 is connected to the first reflux tank 10, so as to introduce the first condensate as the first mixture; a second reboiler 18 is connected to the second rectifying tower 17 for heating the introduced first mixture to vaporize the light radiolysis products therein and retain the kerosene therein in the second reboiler 18; the second condensing mechanism is connected with a gas-phase outlet of the second rectifying tower 17 and is used for condensing gas-phase substances output by the second rectifying tower 17; the inlet of the second reflux drum 22 is connected to the second condensing means and the outlet thereof is connected to the reflux line of the second rectifying tower 17 to return the second condensate obtained in the second condensing means to the second rectifying tower 17.

Specifically, the first reflux drum 10 is further connected to a middle distillate receiving drum 15 through a first reflux pump 11, and a first mixture (i.e., a first condensate having a TBP content of 0.02 wt% or less) extracted from the first reflux drum 10 is first transferred to the middle distillate receiving drum 15 for temporary storage. The feed inlet of the second rectifying tower 17 is connected to the middle distillate receiving tank 15 through the feed pump 16 to feed the first mixture. The second rectification tower 17 preferably adopts a vacuum packing rectification tower, which comprises a second stripping and separating area 171 and a second rectification and separating area 172, wherein the second stripping and separating area 171 and the second rectification and separating area 172 are sequentially distributed from bottom to top and are connected through flanges, each area comprises a plurality of separation stages, the separation stages of the second stripping and separating area 171 are preferably 5-15, and the separation stages of the second rectification and separating area 172 are preferably 3-8. The feed liquid inlet of the second reboiler 18 is connected to the liquid phase outlet of the bottom of the second distillation tower 17, and is used for heating the liquid phase (i.e. the introduced first mixture) output from the second distillation tower 17 to heat the light radiolysis products therein to change into a gas phase (i.e. the second organic vapor), and the kerosene therein is trapped in the second reboiler 18 and then extracted and conveyed to a kerosene receiving tank 19 connected to the liquid phase outlet of the second reboiler 18. The gas phase outlet of the second reboiler 18 is connected to a position below the second rectification separation zone 172 of the second rectification column 17, and is used for returning the second organic vapor generated by heating in the second reboiler 18 to the second rectification column 17, the second organic vapor flows upwards and passes through the second stripping separation zone 171 and the second rectification separation zone 172 in sequence, the second organic vapor can generate mass transfer with the liquid phase (mainly derived from the second condensate of the reflux) flowing downwards in the second rectification column 17 during the rising process, so that the substance with higher boiling point in the second organic vapor is gradually transferred to the liquid phase flowing downwards, and the substance with lower boiling point in the liquid phase is gradually transferred to the first organic vapor flowing upwards, wherein, when the second organic vapor passes through the second stripping separation zone 171, the second organic vapor can generate mass transfer with the substance with low boiling point in the liquid phase (mainly derived from the second condensate of the reflux) flowing downwards, so that the low boiling point material (such as light radiolysis product) in the downward flowing liquid phase is transferred into the ascending second organic vapor, and at the same time, the higher boiling point material in the second organic vapor is preferentially transferred into the downward flowing liquid phase; when the second organic vapor continues to flow upward to pass through the second rectification separation zone 172, the second organic vapor can undergo mass transfer with the liquid phase substance continuing to flow downward, so that high boiling point substances (such as kerosene) in the second organic vapor are transferred to the liquid phase substance flowing downward, thereby gradually realizing separation of kerosene, and the remaining second organic vapor is output to the second condensing mechanism from the gas phase outlet at the top of the first rectification column 4. The second condensing mechanism includes one or more condensers, preferably one condenser in this embodiment, that is, a fourth condenser 20, the fourth condenser 20 is connected to the second rectifying tower 17, a gas phase substance output from a gas phase outlet of the second rectifying tower 17 is condensed by the fourth condenser 20 to obtain a second condensate, the second condensate is conveyed to a second reflux tank 22, a non-condensable gas in the fourth condenser 20 is input into a second trap 21 for gas-liquid separation, liquid droplets separated in the second trap 21 are conveyed to the second reflux tank 22 through a liquid phase outlet of the second trap 21, and a gas separated in the second trap 21 is discharged to a vacuum system through a gas phase outlet of the second trap 21 for subsequent treatment. The second reflux drum 22 is connected to the upper part of the second rectifying tower 17, preferably to the upper position of the second rectifying and separating section 172, by a second reflux pump 23. A third sampling port a3 is provided at the outlet of the second reflux drum 22 so as to sample and analyze the condensate (second condensate) output from the second reflux drum 22. The second reflux drum 22 is further connected to a second residue drum 24, and when the kerosene content in the second condensate reaches the process requirement, the second condensate in the second reflux drum 22 is output to the second residue drum 24, and at this time, all light radiolysis products (such as nitrate, nitrite, hydroximic acid, olefin, carboxylic acid, etc.) are concentrated in the second condensate.

In this embodiment, the fourth condenser 20 preferably adopts a shell-and-tube structure, and all uses chilled water as a condensing medium, and the temperature of the chilled water is preferably no more than 20 ℃.

The following takes the example of the simulation of radioactive organic extractant waste liquid by waste liquid simulant with the composition shown in table 1 (compared with radioactive organic extractant waste liquid, the mixture lacks radionuclide), wherein, water and nitric acid simulate light radiolysis component, dodecyl phosphate simulates heavy radiolysis component, and the radioactive organic extractant waste liquid treatment process is carried out by adopting the system, which is concretely as follows:

the waste liquid simulants shown in Table 1 were fed into the first vacuum distillation column 4 at a feed rate of 181.5kg/h to carry out the first distillation treatment, and the operation steps thereof were the same as those described in example 2 and thus are not repeated herein.

TABLE 1 composition of waste liquid simulants

In the above-mentioned treatment process: the temperature of the preheater 3 is 80 ℃, the top pressure of the first rectifying tower 4 is controlled at 500Pa (absolute pressure), the top temperature of the first rectifying tower 4 is 72 ℃, the bottom temperature of the first rectifying tower 4 is 135 ℃, the top mass reflux ratio of the first rectifying tower 4 is controlled at 3.0, the top pressure of the second rectifying tower 17 is controlled at 10kPa (absolute pressure), the top temperature of the second rectifying tower 17 is 92 ℃, the bottom temperature of the second rectifying tower 17 is 134 ℃, and the mass reflux ratio of the second rectifying tower 17 is controlled at 30.

The composition of the fractions extracted into each material receiving tank in the primary rectification unit and the secondary rectification unit in the treatment process is recorded, and the details are shown in table 2:

TABLE 2 composition of fractions in respective material receiving tanks

As can be seen from table 2, the flow rate of the material received in the TBP receiving tank 13 is 54.177kg, wherein the TBP content is equal to or greater than 84.6 wt.%, while the flow rate of the TBP in the waste liquid simulant before treatment is 58.512kg, and the TBP content is 32.238 wt.%, that is, the TBP treated by the apparatus is mainly concentrated in the TBP receiving tank 13; the total content of various kinds of kerosene in the materials received by the kerosene receiving tank 19 is 99.996 wt.%, the total flow of various kinds of kerosene is about 108kg, and the total flow of various kinds of kerosene in the waste liquid simulant before treatment is about 119kg, that is, the kerosene after treatment by the device is mainly concentrated in the kerosene receiving tank 19; further, the flow rate of dodecyl phosphate in the first residue tank 6 was 0.017kg, and the flow rate of dodecyl phosphate in the waste liquid simulant before treatment was 0.018kg, that is, almost all of the heavy radiolysis products were collected in the first residue tank 6. Therefore, the device can really recover TBP and kerosene in the radioactive organic extractant waste liquid (waste liquid simulant), thereby effectively reducing the volume of the radioactive organic extractant waste liquid, greatly reducing the final disposal quantity of the radioactive organic extractant waste liquid, realizing volume reduction, reducing disposal difficulty and saving disposal cost.

And because the concentration of the recovered TBP is more than or equal to 84.6 wt.% and more than 80% of the process requirement, the TBP content in the recovered kerosene is 0.004 wt.%, and the rest of the TBP content is various kerosene and is more than 0.02 wt.% of the TBP content required by the process, the recovered TBP and kerosene can be returned to a nuclear fuel post-treatment plant for reuse, so that the operation cost of the nuclear fuel post-treatment plant can be saved.

It will be understood that the foregoing is only a preferred embodiment of the invention, and that the invention is not limited thereto. It will be apparent to those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention, and these changes and modifications are to be considered as within the scope of the invention.