Radioactive organic waste liquid recovery method and recovery device used therein

Abstract

The present invention discloses a method for recovering radioactive organic waste liquid and a recovery device used therein. The recovery method comprises the following steps: 1) the radioactive organic waste liquid is first pretreated to remove the insoluble water phase and suspended matter therein, and to elute the excess nitrate and nitric acid; 2) the radiolysis light product, radionuclides and radiolysis heavy product are removed to obtain vaporized organic steam; 3) the vaporized organic steam is subjected to vacuum distillation treatment to separate tributyl phosphate and kerosene. The recovery method of the present invention can not only recover the organic solvent, but also greatly reduce the final disposal amount of the radioactive organic waste liquid, reduce the disposal difficulty and save the disposal and operation costs. The present invention greatly reduces the temperature of the distillation system, realizes the recovery and reuse of tributyl phosphate and kerosene in the radioactive organic waste liquid at a non-boiling temperature, avoids the thermal decomposition reaction of tributyl phosphate with nitric acid, nitrates, etc. at high temperature, improves the safety of system operation and saves energy consumption.

Description

Technical Field

[0001] The invention belongs to the field of nuclear technology, and in particular relates to a method for recovering radioactive organic waste liquid and a recovery device used therein. Background Art

[0002] Nuclear fuel reprocessing plants mostly use the PUREX solvent extraction process, using tributyl phosphate (TBP) as an extractant and hydrocarbons as diluents, such as kerosene, to extract and separate uranium and plutonium from spent fuel. During the extraction process, the organic solvent will degrade under the action of physics, chemistry and radiolysis, producing light radiolysis products (primary degradation products of TBP and kerosene, such as butanol, HDBP, H2MBP, carboxylic acids, organic nitrates, nitrites, nitro compounds, hydroxamic acid, etc.) and heavy radiolysis products (primary products polymerize with each other and complex with fission products to form a series of heavy radiolysis products, such as long-chain alkyl phosphates, metal organic complexes, etc.), causing the extraction effect to gradually decrease and eventually fail to meet the requirements, requiring solvent washing and regeneration. However, as the number of cycles increases, conventional alkaline washing methods do not meet the requirements of regeneration, and the deteriorated solvent needs to be further purified. Distillation is usually used. Distillation is a process of separating different substances based on their different volatilities. It not only does not introduce new reagents, but also can separate radiolysis products, nuclides and organic solvents to achieve the purpose of recovery and reuse.

[0003] The Purex process is based on liquid-liquid extraction between concentrated nitric acid aqueous solution and organic solvent. During the extraction process, tributyl phosphate (TBP) not only has a high solubility for uranium and plutonium, but also has a certain extraction effect on nitrates and can form complexes with nitrates. Therefore, in addition to the radiolysis products, the radioactive organic waste liquid also contains not only TBP and kerosene, but also nitrates and nitric acid. Studies have shown that pure TBP is relatively stable at high temperatures. When nitrogen oxides (nitric acid, metal nitrates, NOx) are present, TBP will be significantly decomposed, causing the working temperature to drop sharply. For example, when different proportions of NO2 are added to TBP, the decomposition temperature of TBP will drop to 80-90°C, and a black substance with complex composition will be produced; in the absence of HNO3, TBP will decompose at 225

[0004] No decomposition phenomenon was found within ℃. The addition of HNO3 will significantly promote the decomposition of TBP. The higher the concentration of nitric acid, the lower the decomposition temperature of TBP. When TBP is present in the presence of nitrates and the temperature is higher than 100℃, the two will interact to form nitro compounds. When the temperature exceeds 130℃, it will decompose violently and even cause an explosion. Therefore, the operation process needs to be controlled at a lower temperature to avoid TBP decomposition or even safety accidents. However, TBP is a high-boiling-point substance with a boiling point of about 289℃ at normal pressure. Even in a vacuum of 500Pa absolute pressure, the boiling point still reaches 141℃, and significant decomposition reactions will still occur. It is very uneconomical to continue to rely on reducing pressure to reduce the operating temperature in industrial-scale production. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a method for recovering radioactive organic waste liquid and a recovery device used therein in view of the above-mentioned deficiencies existing in the prior art, thereby slowing down the decomposition reaction of TBP with nitrates, acids and other substances during the distillation process, reducing the separation temperature, and realizing the recovery and reuse of tributyl phosphate (TBP) and kerosene in the radioactive organic waste liquid at a non-boiling temperature, thereby achieving the volume reduction of radioactive waste.

[0006] The technical solution adopted to solve the technical problem of the present invention is to provide a method for recovering radioactive organic waste liquid, wherein the radioactive organic waste liquid includes: tributyl phosphate (TBP), kerosene, radiolysis light products, radiolysis heavy products, radionuclides, insoluble aqueous phase, suspended matter, nitrate, nitric acid, water, and suspended matter. The recovery method includes the following steps:

[0007] 1) The radioactive organic waste liquid is first pretreated to remove the insoluble aqueous phase and suspended matter, and to elute the excess nitrate and nitric acid;

[0008] 2) removing light radiolysis products, radionuclides and heavy radiolysis products to obtain vaporized organic vapor;

[0009] 3) The vaporized organic vapor is subjected to vacuum distillation to separate tributyl phosphate and kerosene.

[0010] The light products of radiolysis are primary degradation products of tributyl phosphate (TBP) and kerosene, such as butanol, monobutyl phosphate (HDBP), dibutyl phosphate (H2MBP), carboxylic acids, organic nitrates, nitrites, nitro compounds, hydroxamic acid, etc. The heavy products of radiolysis are a series of heavy radiolysis products formed by the mutual polymerization of primary products and complexation with fission products, such as long-chain alkyl phosphates, metal organic complexes, etc.

[0011] Preferably, step 1) specifically comprises: in a mixing and clarifying tank, using a dilute nitric acid solution of a first concentration to stir, mix and clarify the radioactive organic waste liquid, and the insoluble aqueous phase, suspended matter and excessive dissolved nitrate and nitric acid carried in the radioactive organic waste liquid will be eluted into the aqueous phase waste liquid for discharge and removal;

[0012] Step 2) is specifically as follows: the pretreated radioactive organic waste liquid is fed into a vertical liquid preheater, the liquid preheater is operated under the first heating temperature and the first pressure conditions, the radioactive organic waste liquid flows from top to bottom on the inner wall of the heating tube of the liquid preheater, the radiolysis light product and a small amount of dissolved water and dissolved acid contained in the radioactive organic waste liquid are vaporized in the process, flow upward in countercurrent, and are discharged from the top pipe port of the upper head of the liquid preheater, and after passing through the condenser cooler, the non-condensable steam is discharged to the vacuum system, the condensate is discharged into the light oil phase tank, the preheated radioactive organic waste liquid is fed to the falling film evaporator, and the falling film evaporator is operated under the second heating temperature and the second pressure. The radioactive organic waste liquid is operated under the following conditions, and flows from top to bottom inside the heating tube of the falling film evaporator. The kerosene and tributyl phosphate (TBP) in the radioactive organic waste liquid are vaporized in the process, and the vaporized organic vapor flows downward together with the unvaporized liquid, and the gas enters the separation chamber of the falling film evaporator; the liquid enters the residual liquid circulation tank, and is sent back to the upper head circulating liquid inlet of the falling film evaporator by the residual liquid circulation pump, and circulates and evaporates, and the radiolysis heavy products and radionuclides in the radioactive organic waste liquid remain in the unvaporized liquid phase and are discharged as residual liquid, and the vaporized organic vapor enters the vacuum distillation tower after the entrained droplets are separated in the separation chamber of the falling film evaporator;

[0013] Step 3) is specifically as follows: the vacuum distillation tower is operated under the third temperature and third pressure conditions, the vaporized organic steam entering the tower from the feed port of the vacuum distillation tower is continuously condensed in the process of rising, and the liquid droplets fall into the tower kettle reboiler, and after being heated by the tower kettle reboiler, a part of it is converted into organic steam again, and mass transfer is carried out with the falling liquid droplets, and the organic steam is discharged from the top of the vacuum distillation tower together with the uncondensed organic steam, and the organic steam extracted from the gas phase outlet at the top of the vacuum distillation tower is condensed, and after condensing to a fourth temperature, the condensate is returned to the vacuum distillation tower as a reflux liquid for reflux circulation, and the reflux liquid and the organic steam in the vacuum distillation tower are refluxed in the vacuum distillation tower. Mass transfer occurs and the content of tributyl phosphate (TBP) in the rising organic vapor decreases. After multiple cycles until the content of tributyl phosphate (TBP) in the condensate drops to the second concentration, part of the condensate is extracted, which is kerosene, and the other part of the condensate continues to reflux and circulate. The liquid remaining in the reboiler of the tower bottom is sampled. When the content of tributyl phosphate (TBP) in the sample reaches the third concentration, it is extracted by the tower bottom extraction pump. This part of the liquid is tributyl phosphate (TBP). The extracted tributyl phosphate (TBP) is cooled in a tributyl phosphate (TBP) fraction cooler and then enters a tributyl phosphate (TBP) receiving tank.

[0014] Preferably, a stream of tributyl phosphate (TBP) is added from the tower bottom reboiler to the outlet of the separation chamber of the falling film evaporator to balance the stability of the liquid level at the bottom of the heating chamber of the falling film evaporator and to elute and purify the vaporized gas phase in the heating chamber of the falling film evaporator in the separation chamber of the falling film evaporator.

[0015] Preferably, the first concentration in step 1) is 0.01-0.02 mol / L;

[0016] The first heating temperature in the step 2) is 80-110° C., and the first pressure is 4-8 kPa absolute pressure;

[0017] The second heating temperature is 105-125° C., and the second pressure is 0.3-1.0 kPa absolute pressure.

[0018] Preferably, the third temperature described in the step 3) includes: the third temperature at the top of the vacuum distillation tower is 60-75°C, and the third temperature at the bottom of the vacuum distillation tower is 100-125°C; the third pressure includes: the third pressure at the top of the vacuum distillation tower is an absolute pressure of 0.15-0.5 kPa, and the third pressure at the bottom of the vacuum distillation tower is an absolute pressure of 0.4-1.1 kPa.

[0019] Preferably, the fourth temperature is 5-20° C., the second concentration is that the tributyl phosphate content in the condensate is ≤0.02wt%, and the third concentration is that the tributyl phosphate (TBP) content in the sample is ≥80wt%.

[0020] Preferably, the radioactive organic waste liquid is waste tributyl phosphate-kerosene mixed organic waste liquid generated by a nuclear fuel reprocessing plant.

[0021] The present invention also provides a recovery device used in the above-mentioned radioactive organic waste liquid recovery method, comprising:

[0022] The pretreatment unit is used to separate the insoluble aqueous phase and suspended matter in the radioactive organic waste liquid by sedimentation, and to elute nitrate and nitric acid;

[0023] A radiolysis product separation unit is connected to the pretreatment unit, and is used to remove light radiolysis products, radionuclides and heavy radiolysis products;

[0024] The tributyl phosphate (TBP) and kerosene separation unit is connected to the radiolysis product separation unit. The tributyl phosphate (TBP) and kerosene separation unit is used for vacuum distillation of the organic solvent treated by the radiolysis product separation unit to separate it into tributyl phosphate and kerosene.

[0025] Preferably, the pretreatment unit comprises: a liquid receiving tank, a liquid delivery pump, a mixing and clarifying tank, and a discharge pump.

[0026] The liquid receiving tank, the liquid delivery pump, the mixing and clarifying tank, and the discharge pump are sequentially connected through pipelines, and the discharge pump outlet is connected to the radiolysis product separation unit;

[0027] The radioactive organic waste liquid is mixed, stirred and clarified in a mixing and clarification tank to remove the insoluble water phase and suspended matter and reduce the salt and acidity content.

[0028] Preferably, the mixing and settling tank is a two-stage mixing and settling tank, in which the flow ratio of the organic phase to the dilute acid is (10-20):1.

[0029] Preferably, the radiolysis product separation unit comprises: a feed liquid preheater, a feed tank, a feed pump, a condenser cooler, a light oil phase tank, a falling film evaporator, a residual liquid circulation tank, a residual liquid circulation pump, and a residual liquid tank;

[0030] The liquid preheater is connected to a pretreatment unit upstream, the outlet of the liquid preheater is connected to a feed tank, the gas phase outlet of the upper head of the liquid preheater is connected to a condenser cooler, the outlet of the condenser cooler is connected to a light oil phase tank, and the non-condensable steam outlet of the condenser cooler is connected to a vacuum system; the feed tank, the feed pump, and the falling film evaporator are sequentially connected through pipelines; the liquid phase outlets of the heating chamber and the separation chamber of the falling film evaporator are connected to a residual liquid circulation tank, the outlet of the residual liquid circulation tank is connected to a residual liquid circulation pump, and the outlet of the residual liquid circulation pump is respectively connected to the residual liquid tank and the circulating liquid inlet of the upper head of the falling film evaporator through pipelines; the gas phase outlet of the separation chamber of the falling film evaporator is connected to a tributyl phosphate (TBP) and kerosene separation unit; a sampling port is provided at the outlet of the residual liquid circulation pump;

[0031] The pretreated organic waste liquid enters the liquid preheater for preheating, removes the light radiolysis products and at least the preset content of dissolved water and dissolved acid, and enters the falling film evaporator heating chamber for cyclic evaporation. The radioactive nuclides and heavy radiolysis products remain in the liquid phase, and the purified organic vapor is discharged from the gas phase outlet of the separation chamber and enters the tributyl phosphate (TBP) and kerosene separation unit.

[0032] Preferably, the falling film evaporator comprises: a heating chamber and a separation chamber, the material is fed into the falling film evaporator from the upper part of the heating chamber, flows down in a film-like manner along the inner wall of the heat exchange tube in the heating chamber and is partially vaporized along the tube path, a part of the unvaporized material in the heating chamber is circulated into the inlet of the falling film evaporator, and the rest is discharged as residual liquid; the vaporized material is sucked into the gas phase separation chamber of the falling film evaporator by the downstream vacuum; a filler and a liquid distributor are arranged on the top of the separation chamber for purifying the radioactive nuclides and radiolysis products entrained in the separation chamber, and the liquid distributor is arranged above the filler.

[0033] Preferably, the tributyl phosphate (TBP) and kerosene separation unit comprises: a vacuum distillation tower, a tower bottom reboiler, a tower bottom extraction pump, a tributyl phosphate (TBP) fraction cooler, a tributyl phosphate (TBP) receiving tank, a tower top condenser cooler, a gas-liquid separation tank, a tower top reflux tank, a tower top reflux pump, and a kerosene receiving tank;

[0034] The feed inlet of the vacuum distillation tower is connected to the gas phase outlet of the radiolysis product separation unit, and the gas phase outlet of the top of the vacuum distillation tower, the top condenser cooler, the top reflux tank, and the top reflux pump are connected in sequence through pipelines; the non-condensable steam outlet of the top condenser cooler is connected to the gas-liquid separation tank, and the gas phase outlet of the gas-liquid separation tank is connected to the vacuum system; the liquid phase outlet of the gas-liquid separation tank is connected to the top reflux tank; the outlet of the top reflux pump is connected to the reflux port of the vacuum distillation tower and the kerosene receiving tank, and the outlet of the top reflux pump is connected to the kerosene receiving tank. A sampling port is provided on the connecting pipe between them; the lower outlet of the vacuum distillation tower kettle, the kettle reboiler, the kettle extraction pump, the tributyl phosphate (TBP) fraction cooler, and the tributyl phosphate (TBP) receiving tank are connected in sequence through pipes; the gas phase outlet of the kettle reboiler is connected to the vacuum distillation tower kettle; the outlet pipe of the kettle extraction pump is provided with a branch and connected to the radiolysis product separation unit; a sampling port is provided on the pipe connecting the tributyl phosphate (TBP) fraction cooler and the tributyl phosphate (TBP) receiving tank;

[0035] The gas phase outlet at the top of the vacuum distillation tower is connected to the top condenser cooler. The produced kerosene vapor is condensed and cooled and flows to the top reflux tank by gravity. A part of it is returned to the tower as reflux liquid by the top reflux pump, and the rest enters the kerosene receiving tank; the tower bottom reboiler production outlet is connected to the tower bottom production pump, and the produced TBP enters the TBP receiving tank after passing through the TBP fraction cooler, or returns to the liquid phase feed port at the upper end of the falling film evaporator.

[0036] Preferably, the vacuum distillation tower is a vacuum packed distillation tower, which comprises: a distillation separation zone and a stripping separation zone, wherein the stripping separation zone is arranged above the distillation separation zone, and the tower columns in each zone are connected by flanges, the separation stages of the distillation separation zone are 3 to 8, and the separation stages of the stripping separation zone are 1 to 5.

[0037] Preferably, the feeding of radioactive organic waste liquid is continuous, the light radiolysis products are continuously produced, and kerosene, TBP and heavy radiolysis products are continuously or intermittently produced.

[0038] Compared with the existing process conditions, the radioactive organic waste liquid recovery method and the recovery device used in the present invention can not only recover the organic solvent, but also greatly reduce the final disposal amount of the radioactive organic waste liquid (the volume reduction ratio can reach 100:1), reduce the disposal difficulty and save the disposal and operation costs. The present invention greatly reduces the temperature of the distillation system, realizes the recovery and reuse of tributyl phosphate (TBP) and kerosene in the radioactive organic waste liquid at a non-boiling temperature, avoids the thermal decomposition reaction of tributyl phosphate (TBP) with nitric acid, nitrates, etc. at high temperature, improves the safety of system operation and saves energy consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 It is a schematic diagram of the structure of the recovery device used in the method for recovering radioactive organic waste liquid in Example 2 of the present invention.

[0040] In the figure: V1 - liquid receiving tank, P1 - liquid delivery pump, V2 - pickling and desalting tank, P2 - discharge pump, E1 - liquid preheater, E2 - condenser cooler, V3 - light oil phase tank, V4 - feed tank, P3 - feed pump, E3 - falling film evaporator, V6 - residual liquid circulation tank, P4 - residual liquid circulation pump, V5 - residual liquid tank, T1 - vacuum distillation tower, E4 - tower bottom reboiler, P5 - tower bottom extraction pump, E6 ——Tributyl phosphate (TBP) fraction cooler, V9——Tributyl phosphate (TBP) receiving tank, E5——tower top condenser cooler, F1——gas-liquid separation tank, V7——tower top reflux tank, P6——tower top reflux pump, V8——kerosene receiving tank, T1-1——distillation separation zone, T1-2——stripping separation zone, A1——vacuum distillation tower top reflux pipeline sampling port, A2——tributyl phosphate (TBP) component pipeline sampling port, A3——

[0041] Sampling port for distillation residue pipeline. DETAILED DESCRIPTION

[0042] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0043] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0044] In the description of this patent, it should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing this patent and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this patent.

[0045] In the description of this patent, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", and "set" should be understood in a broad sense, for example, it can be fixedly connected or set, or it can be detachably connected or set, or connected or set in one piece. For ordinary technicians in this field, the specific meanings of the above terms in this patent can be understood according to specific circumstances.

[0046] Example 1

[0047] The present embodiment provides a method for recovering radioactive organic waste liquid, wherein the radioactive organic waste liquid includes: tributyl phosphate (TBP), kerosene, radiolysis light products, radiolysis heavy products, radionuclides, insoluble aqueous phase, suspended matter, nitrate, nitric acid, water, and suspended matter. The recovery method includes the following steps:

[0048] 1) The radioactive organic waste liquid is first pretreated to remove the insoluble aqueous phase and suspended matter, and to elute the excess nitrate and nitric acid;

[0049] 2) removing light radiolysis products, radionuclides and heavy radiolysis products to obtain vaporized organic vapor;

[0050] 3) The vaporized organic vapor is subjected to vacuum distillation to separate tributyl phosphate and kerosene.

[0051] This embodiment also provides a recovery device used in the above-mentioned radioactive organic waste liquid recovery method, comprising:

[0052] The pretreatment unit is used to separate the insoluble aqueous phase and suspended matter in the radioactive organic waste liquid by sedimentation, and to elute nitrate and nitric acid;

[0053] A radiolysis product separation unit is connected to the pretreatment unit, and is used to remove light radiolysis products, radionuclides and heavy radiolysis products;

[0054] The tributyl phosphate (TBP) and kerosene separation unit is connected to the radiolysis product separation unit. The tributyl phosphate (TBP) and kerosene separation unit is used for vacuum distillation of the organic solvent treated by the radiolysis product separation unit to separate it into tributyl phosphate and kerosene.

[0055] Compared with the existing process conditions, the method for recovering radioactive organic waste liquid and the recovery device used in this embodiment can not only recover the organic solvent, but also greatly reduce the final disposal amount of radioactive organic waste liquid (the volume reduction ratio can reach 100:1), reduce the disposal difficulty and save the disposal and operation costs. This embodiment greatly reduces the temperature of the distillation system, realizes the recovery and reuse of tributyl phosphate (TBP) and kerosene in the radioactive organic waste liquid at a non-boiling temperature, avoids the thermal decomposition reaction of tributyl phosphate (TBP) with nitric acid, nitrates, etc. at high temperature, improves the safety of system operation and saves energy consumption.

[0056] Example 2

[0057] The present embodiment provides a method for recovering radioactive organic waste liquid, wherein the radioactive organic waste liquid includes tributyl phosphate (TBP), kerosene, radiolysis light products, radiolysis heavy products, radionuclides, insoluble aqueous phase, suspended matter, nitrates, and nitric acid. The recovery method includes the following steps:

[0058] 1) The radioactive organic waste liquid is first pretreated to remove the insoluble aqueous phase and suspended matter, and to elute the excess nitrate and nitric acid;

[0059] 2) removing light radiolysis products, radionuclides and heavy radiolysis products to obtain vaporized organic vapor;

[0060] 3) The vaporized organic vapor is subjected to vacuum distillation to separate tributyl phosphate and kerosene.

[0061] The light products of radiolysis are primary degradation products of tributyl phosphate (TBP) and kerosene, such as butanol, monobutyl phosphate (HDBP), dibutyl phosphate (H2MBP), carboxylic acids, organic nitrates, nitrites, nitro compounds, hydroxamic acid, etc. The heavy products of radiolysis are a series of heavy radiolysis products formed by the mutual polymerization of primary products and complexation with fission products, such as long-chain alkyl phosphates, metal organic complexes, etc.

[0062] Specifically, in this embodiment, the radioactive organic waste liquid is pretreated, the insoluble water phase and suspended matter in the organic waste liquid are separated by sedimentation, and the extracted nitrate and acid are stripped to reduce the concentration; then, after the radiolysis light products, a small amount of dissolved water, dissolved acid, radioactive nuclides and radiolysis heavy products are removed in sequence, vacuum distillation is performed to obtain TBP and kerosene.

[0063] Specifically, the light radiolysis products in step 2) include: nitrates, nitrites, hydroxamic acid, the radionuclides include: Se-79, Sr-90, Pu-239, U-235, and the heavy radiolysis products include: long-chain acid phosphates, acid dipolybutyl phosphate, and long-chain alkyl neutral phosphates.

[0064] Preferably, step 1) specifically comprises: in a mixing and clarifying tank, using a dilute nitric acid solution of a first concentration to stir, mix and clarify the radioactive organic waste liquid, and the insoluble aqueous phase, suspended matter and excessive dissolved nitrate and nitric acid carried in the radioactive organic waste liquid will be eluted into the aqueous phase waste liquid for discharge and removal;

[0065] Step 2) is specifically as follows: the pretreated radioactive organic waste liquid is fed into a vertical liquid preheater, the liquid preheater is operated under the first heating temperature and the first pressure conditions, the radioactive organic waste liquid flows from top to bottom on the inner wall of the heating tube of the liquid preheater, the radiolysis light product and a small amount of dissolved water and dissolved acid contained in the radioactive organic waste liquid are vaporized in the process, flow upward in countercurrent, and are discharged from the top pipe port of the upper head of the liquid preheater, and after passing through the condenser cooler, the non-condensable steam is discharged to the vacuum system, the condensate is discharged into the light oil phase tank, the preheated radioactive organic waste liquid is fed to the falling film evaporator, and the falling film evaporator is operated under the second heating temperature and the second pressure. The radioactive organic waste liquid is operated under the following conditions, and flows from top to bottom inside the heating tube of the falling film evaporator. The kerosene and tributyl phosphate (TBP) in the radioactive organic waste liquid are vaporized in the process, and the vaporized organic vapor flows downward together with the unvaporized liquid, and the gas enters the separation chamber of the falling film evaporator; the liquid enters the residual liquid circulation tank, and is sent back to the upper head circulating liquid inlet of the falling film evaporator by the residual liquid circulation pump, and circulates and evaporates, and the radiolysis heavy products and radionuclides in the radioactive organic waste liquid remain in the unvaporized liquid phase and are discharged as residual liquid, and the vaporized organic vapor enters the vacuum distillation tower after the entrained droplets are separated in the separation chamber of the falling film evaporator;

[0066] Step 3) is specifically as follows: the vacuum distillation tower is operated under the third temperature and third pressure conditions, the vaporized organic steam entering the tower from the feed port of the vacuum distillation tower is continuously condensed in the process of rising, and the liquid droplets fall into the tower kettle reboiler, and after being heated by the tower kettle reboiler, a part of it is converted into organic steam again, and mass transfer is carried out with the falling liquid droplets, and the organic steam is discharged from the top of the vacuum distillation tower together with the uncondensed organic steam, and the organic steam extracted from the gas phase outlet at the top of the vacuum distillation tower is condensed, and after condensing to a fourth temperature, the condensate is returned to the vacuum distillation tower as a reflux liquid for reflux circulation, and the reflux liquid and the organic steam in the vacuum distillation tower are refluxed in the vacuum distillation tower. Mass transfer occurs and the content of tributyl phosphate (TBP) in the rising organic vapor decreases. After multiple cycles until the content of tributyl phosphate (TBP) in the condensate drops to the second concentration, part of the condensate is extracted, which is kerosene, and the other part of the condensate continues to reflux and circulate. The liquid remaining in the reboiler of the tower bottom is sampled. When the content of tributyl phosphate (TBP) in the sample reaches the third concentration, it is extracted by the tower bottom extraction pump. This part of the liquid is tributyl phosphate (TBP). The extracted tributyl phosphate (TBP) is cooled in a tributyl phosphate (TBP) fraction cooler and then enters a tributyl phosphate (TBP) receiving tank.

[0067] Preferably, the outlet of the tower bottom reboiler is simultaneously introduced into a liquid replenishing pipe at the inlet of the falling film reboiler, and a high-concentration tributyl phosphate (TBP) is replenished from the tower bottom reboiler to the outlet of the separation chamber of the falling film evaporator. When the falling film evaporator is operated continuously or at a low liquid level, a high-concentration TBP component is replenished to balance the stability of the liquid level at the bottom of the heating chamber of the falling film evaporator, and to elute and purify the gas phase vaporized in the heating chamber of the falling film evaporator in the separation chamber of the falling film evaporator.

[0068] Preferably, the first concentration in step 1) is 0.01-0.02 mol / L;

[0069] The first heating temperature in the step 2) is 80-110° C., and the first pressure is 4-8 kPa absolute pressure;

[0070] The second heating temperature is 105-125° C., and the second pressure is 0.3-1.0 kPa absolute pressure.

[0071] Preferably, the third temperature described in the step 3) includes: the third temperature at the top of the vacuum distillation tower is 60-75°C, and the third temperature at the bottom of the vacuum distillation tower is 100-125°C; the third pressure includes: the third pressure at the top of the vacuum distillation tower is an absolute pressure of 0.15-0.5 kPa, and the third pressure at the bottom of the vacuum distillation tower is an absolute pressure of 0.4-1.1 kPa.

[0072] Preferably, the fourth temperature is 5-20° C., the second concentration is that the tributyl phosphate content in the condensate is ≤0.02wt%, and the third concentration is that the tributyl phosphate (TBP) content in the sample is ≥80wt%.

[0073] Preferably, the radioactive organic waste liquid is waste tributyl phosphate-kerosene mixed organic waste liquid generated by a nuclear fuel reprocessing plant.

[0074] Specifically, this embodiment provides a method for recovering radioactive organic waste liquid, such as Figure 1 As shown, the following steps are included:

[0075] S201, in the mixing and clarifying tank, the radioactive organic waste liquid and 0.02 mol / L dilute nitric acid are countercurrently mixed and stirred in two stages to separate the insoluble water phase, suspended matter, excess nitrate and extraction acid in the radioactive organic waste liquid. The flow ratio of the organic phase to the aqueous phase is 20:1.

[0076] S202, the treated radioactive organic waste liquid is sent to the vertical liquid preheater. In this embodiment, the operating temperature of the liquid preheater is 80°C, the operating pressure is 4kPa absolute pressure, and the radioactive organic waste liquid flows from top to bottom on the inner wall of the heating tube. The light products of radiolysis (such as nitrates, nitrites, hydroxamic acid, etc.), a small amount of dissolved water, and dissolved acid contained in the liquid preheater are vaporized in the process, countercurrently discharged from the top pipe mouth of the upper head of the liquid preheater, and after being cooled to 20°C by the condenser cooler, the non-condensable steam is discharged to the vacuum system, and the condensate flows into the light oil phase tank by gravity. The preheated radioactive organic waste liquid is sent to the falling film evaporator for cyclic evaporation. The operating temperature of the falling film evaporator is 114°C, and the operating pressure is 0.6kPa absolute pressure. The radioactive organic waste liquid flows from top to bottom inside the heating tube of the falling film evaporator, and kerosene and TBP are vaporized in the process. The vaporized organic vapor and the unvaporized liquid flow downward in parallel, and the gas enters the separation chamber of the falling film evaporator to separate and purify the entrained nuclides, and then enters the vacuum distillation tower; the unvaporized liquid enters the residual liquid circulation tank, and the unvaporized liquid is enriched with the radiolysis heavy products (such as long-chain acid phosphates, acid dipolybutyl phosphate, long-chain alkyl neutral phosphates, etc.) and radionuclides (such as Se-79, Sr-90, Pu-239, U-235, etc.) in the radioactive organic waste liquid. A part of the unvaporized liquid is sent back to the circulating feed liquid inlet of the upper head of the falling film evaporator by the residual liquid circulation pump for cyclic evaporation to ensure the minimum liquid amount required for the operation of the falling film evaporator, and the other part is discharged continuously or intermittently as residual liquid.

[0077] S203, the operating temperature of the vacuum distillation tower in this embodiment is 64-118°C, and the operating pressure is 0.3-0.8kPa absolute pressure. Specifically, the operating temperature of the tower bottom is 118°C, the operating pressure is 0.8kPa absolute pressure, and the operating temperature of the tower top is 64°C, and the operating pressure is 0.3kPa absolute pressure. The organic vapor entering the tower from the feed port of the vacuum distillation tower continuously condenses during the rising process, and the droplets fall into the tower bottom reboiler. After being heated by the tower bottom reboiler, a part of it becomes organic vapor again, and mass transfers with the falling droplets, and is discharged from the top of the vacuum distillation tower together with the uncondensed organic vapor. The organic vapor extracted from the gas phase outlet at the top of the vacuum distillation tower is condensed, and after condensation and cooling to 20°C, the condensate is returned to the vacuum distillation tower as a reflux liquid for reflux circulation. The reflux liquid and the organic vapor in the vacuum distillation tower are mass transferred in the vacuum distillation tower to reduce the TBP content in the rising organic vapor. After multiple cycles until the TBP content in the condensate drops to ≤0.02wt%, part of the condensate is extracted and sent to the kerosene receiving tank. This part of the condensate is the kerosene. The other part of the condensate continues to reflux. In this embodiment, the reflux ratio (i.e., the ratio of the condensate flow rate returned to the vacuum distillation tower (T1) to the condensate flow rate extracted to the kerosene receiving tank (V8)) is 1. The liquid remaining in the tower bottom reboiler is sampled, and when the TBP content is ≥80wt%, it is extracted by the tower bottom extraction pump. This part of the liquid is the TBP. The extracted TBP is cooled to 40°C by the TBP fraction cooler and then enters the TBP receiving tank. At the same time, a high-concentration TBP component is added to the outlet of the falling film evaporator separation chamber from the tower bottom reboiler to balance the stability of the liquid level at the bottom of the falling film evaporator heating chamber; and the vaporized gas phase in the falling film evaporator heating chamber is eluted and purified in the separation chamber.

[0078] like Figure 1 As shown, this embodiment also provides a recovery device used in the above-mentioned radioactive organic waste liquid recovery method, including:

[0079] The pretreatment unit is used to separate the insoluble aqueous phase and suspended matter in the radioactive organic waste liquid by sedimentation, and to elute nitrate and nitric acid;

[0080] A radiolysis product separation unit is connected to the pretreatment unit, and is used to remove light radiolysis products, radionuclides and heavy radiolysis products;

[0081] The tributyl phosphate (TBP) and kerosene separation unit is connected to the radiolysis product separation unit. The tributyl phosphate (TBP) and kerosene separation unit is used for vacuum distillation of the organic solvent treated by the radiolysis product separation unit to separate it into tributyl phosphate and kerosene.

[0082] Specifically, the pretreatment unit in this embodiment is used to perform sedimentation separation on the insoluble aqueous phase and suspended matter in the radioactive organic waste liquid; and to perform stripping separation on the extracted salt and extracted acid in the radioactive organic waste liquid.

[0083] The radiolysis product separation unit is used to separate the radiolysis products from most of the radionuclides, a small amount of dissolved water and dissolved acid in the radioactive organic waste liquid. First, it enters the liquid preheater to remove the light radiolysis products, and then enters the falling film evaporator to separate the radionuclides and heavy radiolysis products in the heating chamber of the falling film evaporator.

[0084] The tributyl phosphate (TBP) and kerosene separation unit is used to perform vacuum distillation on the vaporized gas phase in the separation chamber of the falling film evaporator, recover kerosene at the top of the vacuum distillation tower, and recover TBP at the bottom of the tower.

[0085] Preferably, the pretreatment unit comprises: a liquid receiving tank (V1), a liquid delivery pump (P1), a mixing and clarifying tank (V2), and a discharge pump (P2).

[0086] The liquid receiving tank (V1), the liquid delivery pump (P1), the mixing and clarifying tank (V2), and the discharge pump (P2) are sequentially connected through pipelines, and the outlet of the discharge pump (P2) is connected to the radiolysis product separation unit;

[0087] The radioactive organic waste liquid is mixed, stirred and clarified in a mixing and clarifying tank (V2) to remove the insoluble water phase and suspended matter and reduce the salt and acidity content.

[0088] Preferably, the mixing and settling tank (V2) is a two-stage mixing and settling tank, in which the flow ratio of the organic phase to the dilute acid is (10-20):1.

[0089] Preferably, the radiolysis product separation unit comprises: a feed liquid preheater (E1), a feed tank (V4), a feed pump (P3), a condenser cooler (E2), a light oil phase tank (V3), a falling film evaporator (E3), a residual liquid circulation tank (V6), a residual liquid circulation pump (P4), and a residual liquid tank (V5);

[0090] The liquid preheater (E1) is connected to the outlet of the discharge pump (P2) of the pretreatment unit upstream, the outlet of the liquid preheater (E1) is connected to the feed tank (V4), the gas phase outlet of the upper head of the liquid preheater (E1) is connected to the condenser cooler (E2), the outlet of the condenser cooler (E2) is connected to the light oil phase tank (V3), and the non-condensable steam outlet of the condenser cooler (E2) is connected to the vacuum system; the feed tank (V4), the feed pump (P3), and the falling film evaporator (E3) are connected in sequence through pipelines; the falling film evaporator ( The liquid phase outlets of the heating chamber and the separation chamber of the falling film evaporator (E3) are connected to the residual liquid circulation tank (V6), the outlet of the residual liquid circulation tank (V6) is connected to the residual liquid circulation pump (P4), and the outlet of the residual liquid circulation pump (P4) is connected to the residual liquid tank (V5) and the circulating liquid inlet of the upper head of the falling film evaporator (E3) through pipelines; the gas phase outlet of the separation chamber of the falling film evaporator (E3) is connected to the feed inlet of the vacuum distillation tower (T1) of the tributyl phosphate (TBP) and kerosene separation unit; the outlet of the residual liquid circulation pump (P4) is provided with a sampling port (A3);

[0091] The pretreated organic waste liquid enters the liquid preheater (E1) for preheating, removes the radiolysis light products and at least a preset content of dissolved water and dissolved acid, and enters the falling film evaporator (E3) heating chamber for cyclic evaporation. The radioactive nuclides and radiolysis heavy products remain in the liquid phase, and the purified organic vapor is discharged from the gas phase outlet of the separation chamber and enters the tributyl phosphate (TBP) and kerosene separation unit.

[0092] Preferably, the falling film evaporator (E3) comprises: a heating chamber and a separation chamber, the material is fed into the falling film evaporator from the upper part of the heating chamber, flows down in a film-like manner along the inner wall of the heat exchange tube in the heating chamber and is partially vaporized along the tube path, a part of the material not vaporized in the heating chamber is circulated and fed into the inlet of the falling film evaporator (E3), and the rest is discharged as residual liquid; the vaporized material is sucked into the gas phase separation chamber of the falling film evaporator by the downstream vacuum; a filler and a liquid distributor are arranged on the top of the separation chamber for purifying the radioactive nuclides and radiolysis products entrained in the separation chamber, and the liquid distributor is arranged above the filler.

[0093] Preferably, the tributyl phosphate (TBP) and kerosene separation unit comprises: a vacuum distillation tower (T1), a tower bottom reboiler (E4), a tower bottom extraction pump (P5), a tributyl phosphate (TBP) fraction cooler (E6), a tributyl phosphate (TBP) receiving tank (V9), a tower top condenser cooler (E5), a gas-liquid separation tank (F1), a tower top reflux tank (V7), a tower top reflux pump (P6), and a kerosene receiving tank (V8);

[0094] The feed inlet of the vacuum distillation tower (T1) is connected to the gas phase outlet of the separation chamber of the falling film evaporator (E3) of the radiolysis product separation unit; the gas phase outlet of the top of the vacuum distillation tower (T1), the top condenser cooler (E5), the top reflux tank (V7), and the top reflux pump (P6) are connected in sequence through pipelines; the non-condensable steam outlet of the top condenser cooler (E5) is connected to the gas-liquid separation tank (F1), and the gas phase outlet of the gas-liquid separation tank (F1) is connected to the vacuum system; the liquid phase outlet of the gas-liquid separation tank (F1) is connected to the top reflux tank (V7); the outlet of the top reflux pump (P6) is connected to the reflux port of the vacuum distillation tower (T1) and the kerosene receiving tank (V8), and the outlet of the top reflux pump (P6) is connected to the kerosene receiving tank (V8). A sampling port (A1) is provided on the connecting pipeline between the receiving tank (V8); the lower outlet of the tower kettle of the vacuum distillation tower (T1), the tower kettle reboiler (E4), the tower kettle extraction pump (P5), the tributyl phosphate (TBP) fraction cooler (E6), and the tributyl phosphate (TBP) receiving tank (V9) are sequentially connected through pipelines; the gas phase outlet of the tower kettle reboiler (E4) is connected to the tower kettle of the vacuum distillation tower (T1); the outlet pipeline of the tower kettle extraction pump (P5) is provided with a branch and connected to the falling film evaporator (E3) of the radiolysis product separation unit; a sampling port (A2) is provided on the connecting pipeline between the tributyl phosphate (TBP) fraction cooler (E6) and the tributyl phosphate (TBP) receiving tank (V9);

[0095] The gas phase outlet at the top of the vacuum distillation tower (T1) is connected to the top condenser cooler (E5). The produced kerosene vapor is condensed and cooled and flows to the top reflux tank (V7) by gravity. A part of it is returned to the tower as reflux liquid by the top reflux pump (P6), and the rest enters the kerosene receiving tank (V8); the production outlet of the tower bottom reboiler (E4) is connected to the tower bottom production pump (P5), and the produced TBP enters the TBP receiving tank (V9) or returns to the liquid phase feed port at the upper end of the falling film evaporator after passing through the TBP fraction cooler (E6).

[0096] Preferably, the vacuum distillation tower (T1) is a vacuum packed distillation tower, and the vacuum distillation tower (T1) comprises: a distillation separation zone (T1-1) and a stripping separation zone (T1-2), wherein the stripping separation zone (T1-2) is arranged above the distillation separation zone (T1-1), and the tower columns in each zone are connected by flanges, and each zone comprises a plurality of separation stages, wherein the number of separation stages in the distillation separation zone (T1-1) is 3 to 8, and the number of separation stages in the stripping separation zone (T1-2) is 1 to 5.

[0097] Preferably, the feeding of radioactive organic waste liquid is continuous, the light radiolysis products are continuously produced, and kerosene, TBP and heavy radiolysis products are continuously or intermittently produced.

[0098] Specifically, in this embodiment, the radioactive organic waste liquid is mixed, stirred, and clarified in a mixing and clarifying tank (V2) to remove the insoluble water phase and suspended matter and reduce the salt and acid content;

[0099] The pretreated organic waste liquid enters the liquid preheater (E1) for preheating, removes the radiolysis light products and a small amount of dissolved water and dissolved acid, and enters the falling film evaporator (E3) heating chamber for cyclic evaporation. The radioactive nuclides and radiolysis heavy products remain in the liquid phase. The purified organic vapor is discharged from the gas phase outlet of the separation chamber and enters the vacuum distillation tower (T1);

[0100] The gas phase outlet at the top of the vacuum distillation tower (T1) is connected to the top condenser cooler (E5). The extracted kerosene vapor is condensed and cooled and flows to the top reflux tank (V7) by gravity. A part of it is returned to the tower as reflux liquid by the top reflux pump (P6), and the rest enters the kerosene receiving tank (V8);

[0101] The extraction outlet of the tower bottom reboiler (E4) is connected to the tower bottom extraction pump (P5). The extracted TBP passes through the TBP fraction cooler (E6) and then enters the TBP receiving tank (V9), or returns to the liquid phase feed port at the upper end of the falling film evaporator.

[0102] The operation method of the recovery device used in the method for recovering radioactive organic waste liquid in this embodiment is as follows:

[0103] The feed liquid preheater (E1), the falling film evaporator (E3) and the vacuum distillation tower (T1) are evacuated.

[0104] 0.12MPa saturated water vapor is introduced into the liquid preheater (E1); the mixing and clarifying tank (V2) is opened and 0.02mol / L dilute nitric acid solution is introduced to pretreat the radioactive organic waste liquid; the pretreated radioactive organic waste liquid is sent to the liquid preheater (E1) by the discharge pump (P2), and the valve on the steam supply pipeline is adjusted to control the temperature within the range of 80°C; the condensation cooler (E2) is opened, and the removed light phase radiolysis products and water are condensed and cooled and then enter the light oil phase tank (V3); the organic liquid from which the light phase radiolysis products and water are removed enters the feed tank (V4).

[0105] The organic waste liquid in the feed tank (V4) is fed into the falling film evaporator (E3) through the feed pump (P3) and flows by gravity into the residual liquid circulation tank (V6). When the liquid level in the residual liquid circulation tank (V6) reaches the high level, stop feeding. Start the residual liquid circulation pump (P4) and adjust the circulation flow rate to the set value. Introduce 0.12MPa saturated water vapor into the falling film evaporator (E3) to start circulating evaporation of the organic waste liquid. At the same time, open the tower top condenser cooler (E5). When the liquid level in the residual liquid circulation tank (V6) reaches the low level, feed in time to replenish the organic waste liquid. As the TBP concentration in the feed liquid of the residual liquid circulation tank (V6) increases, the temperature in the falling film evaporator (E3) gradually increases. When the temperature reaches 113-115°C (the pressure is 0.6kPa absolute pressure), start continuous feeding and adjust the steam flow rate to keep the liquid level in the residual liquid circulation tank (V6) stable.

[0106] The organic waste liquid vaporized by the falling film evaporator (E3) enters the vacuum distillation tower (T1), part of which condenses and falls into the tower bottom during the rising process, and part of which enters the tower top reflux tank (V7) after being condensed by the tower top condenser cooler (E5). The feed liquid in the tower top reflux tank (V7) is pumped into the tower bottom reboiler by the tower top reflux pump (P6). When the liquid level of the tower bottom reboiler (E4) is 100 to 200 mm higher than the heating tube, stop feeding and heating the falling film evaporator (E3), and the residual liquid circulation pump (P4) is still running. Steam is introduced into the tower bottom reboiler (E4) to control its temperature to ~118°C (pressure is 0.8 kPa absolute pressure). Kerosene and part of TBP are heated to become organic vapor, which enters the stripping and separation zone (T1-2) of the vacuum distillation tower (T1) from the gas phase outlet on the tower bottom reboiler (E4), passes through the stripping and separation zone (T1-2) and the distillation and separation zone (T1-1) in sequence, and enters the pipe side of the tower top condenser cooler (E5), exchanges heat with the shell side chilled water of the tower top condenser cooler (E5) to condense and cool, and the condensate enters the tower top reflux tank (V7), and the non-condensable vapor separates the entrained droplets through the gas-liquid separation tank (F1), and the captured droplets are also sent to the tower top reflux tank (V7). When the liquid level in the tower top reflux tank (V7) reaches 1 / 2 to 2 / 3, the tower top reflux pump (P6) is turned on to allow part of the liquid in the reflux tank (V2) to enter the vacuum distillation tower (T1) for reflux. The steam flow rate of the tower bottom reboiler (E4) is adjusted to keep the liquid level in the tower top reflux tank (V7) stable. After a period of stable circulation, the liquid therein is sampled and tested. If the TBP content in the condensate is greater than 0.02wt.%, the reflux rate is increased to continue the above circulation; if the TBP content in the condensate is ≤0.02wt.%, part of the condensate in the tower top reflux tank (V7) is extracted into the kerosene receiving tank (V8) according to the set ratio. The tower bottom extraction pump (P5) and the TBP fraction cooler (E6) are turned on to sample and analyze the feed liquid in the tower bottom reboiler (E4). If the TBP content in the sample is ≥80wt.%, it is extracted according to the set flow rate and sent to the TBP receiving tank (V9) for recycling and reuse; if the TBP content in the sample is less than 80wt.%, the steam flow rate of the tower bottom reboiler (E4) is appropriately adjusted for further concentration. During the start-up process of the vacuum distillation tower, if the distance between the liquid level in the tower bottom reboiler (E4) and the heating tube is less than 100 mm, the falling film evaporator (E3) is fed and heated to replenish the feed liquid for the vacuum distillation tower (T1). After the start-up of the vacuum distillation tower (T1) is stable, the feed pump (P3) is turned on to feed and steam is introduced into the falling film evaporator (E3) to continuously feed the vacuum distillation tower (T1). During the feeding process, the feed flow rate must match the top extraction amount and the bottom extraction amount.During stable operation, a high concentration of TBP component is added from the tower bottom reboiler (E4) to the outlet of the separation chamber of the falling film evaporator (E3) to stabilize the liquid level at the bottom of the heating chamber of the falling film evaporator. At the same time, the vaporized gas phase in the heating chamber of the falling film evaporator is eluted and purified in the separation chamber.

[0107] Taking the simulated feed liquid (waste liquid simulant) of the composition shown in Table 1 as an example, the radioactive organic waste liquid treatment process using the above recovery device is as follows:

[0108] Table 1 Composition of simulated liquid

[0109]

[0110]

[0111] The operation method is the same as above. First, 0.02mol / L dilute nitric acid and the simulated feed liquid in Table 1 are sent to the pickling and desalting tank (V2) for mixed stirring and clarification pretreatment, and then sent to the feed liquid preheater (E1) for preheating to 80°C. The temperature of the falling film evaporator (E3) is 114°C, the pressure is 600Pa absolute pressure, and the circulation flow rate is 3500L / h. The bottom temperature of the vacuum distillation tower (T1) is 118°C, the top of the tower is 300Pa absolute pressure, the bottom of the tower is 800Pa absolute pressure, the top reflux ratio is 1.0, the theoretical plate number is 9, and the product composition of each step is shown in Table 2.

[0112] Table 2 Composition of products extracted from various components of the recovery device V2, V3, V4, E3, T1

[0113]

[0114]

[0115] As can be seen from Table 1 and Table 2, after the radioactive waste organic phase was pretreated in the pickling and desalting tank (V2), the acidity was reduced from 0.13mol / L to 0.003mol / L, and the nitrate (sodium nitrate, strontium nitrate, cesium nitrate) was reduced from 13.3mg / L to 5.4mg / L, the acidity was removed by 97%, and the salts were removed by 59%. After preheating in the liquid preheater (E1) to remove residual water and acid, the water content was reduced from 1.5wt.% to 0.11wt.%, and the acid concentration was further reduced to 0.00001mol / L, which was almost completely removed. After being treated in the falling film evaporator (E3), the sodium nitrate content in the material finally entering the distillation tower (T1) was only 1.3mg / L, strontium nitrate was 0.07mg / L, cesium nitrate was completely removed, and the heavy radiolysis product long-chain alkyl phosphate was 3.4E-7mol / L. After the pretreatment unit and the radiolysis product separation unit, compared with the feed, the removal rates of water, nitric acid, U, sodium nitrate, strontium nitrate, and cesium nitrate long-chain alkyl phosphate reached 100%, 100%, 84%, 90%, 87%, 100%, and 99.6%, respectively. It can be seen from the table that the radioactive nuclides and heavy radiolysis products in the treated waste organic phase are mainly concentrated in the residual liquid, and the volume of the generated residual liquid is 99% less than that of the original waste organic phase, and the volume reduction ratio reaches 101.7:1, which greatly reduces the amount of waste that needs to be further processed. The radioactive organic waste liquid recovery method and the recovery device used in this embodiment slow down the decomposition reaction of TBP with nitrates, acids and other substances during the distillation process, reduce the separation temperature, and realize the recovery and reuse of tributyl phosphate (TBP) and kerosene in the radioactive organic waste liquid at a non-boiling temperature, thereby reducing the volume of radioactive waste.

[0116] Compared with the existing process conditions, the method for recovering radioactive organic waste liquid and the recovery device used in this embodiment can not only recover the organic solvent, but also greatly reduce the final disposal amount of radioactive organic waste liquid (the volume reduction ratio can reach 100:1), reduce the disposal difficulty and save the disposal and operation costs. This embodiment greatly reduces the temperature of the distillation system, realizes the recovery and reuse of tributyl phosphate (TBP) and kerosene in the radioactive organic waste liquid at a non-boiling temperature, avoids the thermal decomposition reaction of tributyl phosphate (TBP) with nitric acid, nitrates, etc. at high temperature, improves the safety of system operation and saves energy consumption. The volume reduction of radioactive organic waste liquid is achieved, and the volume reduction ratio reaches 100:1, reducing the amount of waste that needs to be treated later.

[0117] Example 3

[0118] This embodiment provides a method for recovering radioactive organic waste liquid using the recovery device in Embodiment 2, comprising the following steps:

[0119] S301, in the mixing and clarifying tank, the radioactive organic waste liquid and 0.01 mol / L dilute nitric acid are countercurrently mixed and stirred in two stages to separate the insoluble water phase, suspended matter, excess nitrate and extraction acid in the radioactive organic waste liquid. The flow ratio of the organic phase to the aqueous phase is 10:1.

[0120] S302, the treated radioactive organic waste liquid is sent to the vertical liquid preheater. In this embodiment, the operating temperature of the liquid preheater is 100°C, the operating pressure is 8kPa absolute pressure, and the radioactive organic waste liquid flows from top to bottom on the inner wall of the heating tube. The light products of radiolysis (such as nitrates, nitrites, hydroxamic acid, etc.), a small amount of dissolved water, and dissolved acid contained in the liquid preheater are vaporized in the process, countercurrently discharged from the top pipe port of the upper head of the liquid preheater, and after being cooled to 20°C by the condenser cooler, the non-condensable steam is discharged to the vacuum system, and the condensate flows into the light oil phase tank by gravity. The preheated radioactive organic waste liquid is sent to the falling film evaporator for cyclic evaporation. The operating temperature of the falling film evaporator is 105°C, and the operating pressure is 0.3kPa absolute pressure. The radioactive organic waste liquid flows from top to bottom inside the heating tube of the falling film evaporator, and kerosene and TBP are vaporized in the process. The vaporized organic vapor and the unvaporized liquid flow downward in parallel, and the gas enters the separation chamber of the falling film evaporator to separate and purify the entrained nuclides, and then enters the vacuum distillation tower; the unvaporized liquid enters the residual liquid circulation tank, and the unvaporized liquid is enriched with the radiolysis heavy products (such as long-chain acid phosphates, acid dipolybutyl phosphate, long-chain alkyl neutral phosphates, etc.) and radionuclides (such as Se-79, Sr-90, Pu-239, U-235, etc.) in the radioactive organic waste liquid. A part of the unvaporized liquid is sent back to the circulating feed liquid inlet of the upper head of the falling film evaporator by the residual liquid circulation pump for cyclic evaporation to ensure the minimum liquid amount required for the operation of the falling film evaporator, and the other part is discharged continuously or intermittently as residual liquid.

[0121] S303, in this embodiment, the operating temperature of the vacuum distillation tower is 60-100°C, and the operating pressure is 0.15-0.4kPa absolute pressure. Specifically, the operating temperature of the tower bottom is 100°C, the operating pressure is 0.4kPa absolute pressure, and the operating temperature of the tower top is 60°C, and the operating pressure is 0.15kPa absolute pressure. The organic vapor entering the tower from the feed port of the vacuum distillation tower continuously condenses during the rising process, and the droplets fall into the tower bottom reboiler. After being heated by the tower bottom reboiler, a part of it becomes organic vapor again, and mass transfers with the falling droplets, and is discharged from the top of the vacuum distillation tower together with the uncondensed organic vapor. The organic vapor extracted from the gas phase outlet at the top of the vacuum distillation tower is condensed, and after condensation and cooling to 5°C, the condensate is returned to the vacuum distillation tower as a reflux liquid for reflux circulation. The reflux liquid and the organic vapor in the vacuum distillation tower are mass transferred in the vacuum distillation tower to reduce the TBP content in the rising organic vapor. After multiple cycles until the TBP content in the condensate drops to ≤0.02wt%, part of the condensate is extracted and sent to the kerosene receiving tank. This part of the condensate is the kerosene. The other part of the condensate continues to reflux. In this embodiment, the reflux ratio (i.e., the ratio of the condensate flow rate returned to the vacuum distillation tower (T1) to the condensate flow rate extracted to the kerosene receiving tank (V8)) is 0.5. The liquid remaining in the tower bottom reboiler is sampled, and when the TBP content is ≥80wt%, it is extracted by the tower bottom extraction pump, and this part of the liquid is the TBP. The extracted TBP is cooled to 40°C by the TBP fraction cooler and then enters the TBP receiving tank. At the same time, a high-concentration TBP component is added to the outlet of the falling film evaporator separation chamber from the tower bottom reboiler to balance the stability of the liquid level at the bottom of the falling film evaporator heating chamber; and the vaporized gas phase in the falling film evaporator heating chamber is eluted and purified in the separation chamber.

[0122] Compared with the existing process conditions, the method for recovering radioactive organic waste liquid and the recovery device used in this embodiment can not only recover the organic solvent, but also greatly reduce the final disposal amount of radioactive organic waste liquid (the volume reduction ratio can reach 100:1), reduce the disposal difficulty and save the disposal and operation costs. This embodiment greatly reduces the temperature of the distillation system, realizes the recovery and reuse of tributyl phosphate (TBP) and kerosene in the radioactive organic waste liquid at a non-boiling temperature, avoids the thermal decomposition reaction of tributyl phosphate (TBP) with nitric acid, nitrates, etc. at high temperature, improves the safety of system operation and saves energy consumption. The volume reduction of radioactive organic waste liquid is achieved, and the volume reduction ratio reaches 100:1, reducing the amount of waste that needs to be treated later.

[0123] Example 4

[0124] This embodiment provides a method for recovering radioactive organic waste liquid using the recovery device in Embodiment 2, comprising the following steps:

[0125] S401, in the mixing and clarifying tank, the radioactive organic waste liquid and 0.015 mol / L dilute nitric acid are countercurrently mixed and stirred in two stages to separate the insoluble water phase, suspended matter, excess nitrate and extraction acid in the radioactive organic waste liquid. The flow ratio of the organic phase to the aqueous phase is 20:1.

[0126] S402, the treated radioactive organic waste liquid is sent to the vertical liquid preheater. In this embodiment, the operating temperature of the liquid preheater is 110°C, the operating pressure is 6kPa absolute pressure, and the radioactive organic waste liquid flows from top to bottom on the inner wall of the heating tube. The light products of radiolysis (such as nitrates, nitrites, hydroxamic acid, etc.), a small amount of dissolved water, and dissolved acid contained in the liquid preheater are vaporized in the process, countercurrently discharged from the top pipe mouth of the upper head of the liquid preheater, and after being cooled to 20°C by the condenser cooler, the non-condensable steam is discharged to the vacuum system, and the condensate flows into the light oil phase tank by gravity. The preheated radioactive organic waste liquid is sent to the falling film evaporator for cyclic evaporation. The operating temperature of the falling film evaporator is 125°C, and the operating pressure is 1.0kPa absolute pressure. The radioactive organic waste liquid flows from top to bottom inside the heating tube of the falling film evaporator, and kerosene and TBP are vaporized in the process. The vaporized organic vapor and the unvaporized liquid flow downward in parallel, and the gas enters the separation chamber of the falling film evaporator to separate and purify the entrained nuclides, and then enters the vacuum distillation tower; the unvaporized liquid enters the residual liquid circulation tank, and the unvaporized liquid is enriched with the radiolysis heavy products (such as long-chain acid phosphates, acid dipolybutyl phosphate, long-chain alkyl neutral phosphates, etc.) and radionuclides (such as Se-79, Sr-90, Pu-239, U-235, etc.) in the radioactive organic waste liquid. A part of the unvaporized liquid is sent back to the circulating feed liquid inlet of the upper head of the falling film evaporator by the residual liquid circulation pump for cyclic evaporation to ensure the minimum liquid amount required for the operation of the falling film evaporator, and the other part is discharged continuously or intermittently as residual liquid.

[0127] S403, in this embodiment, the operating temperature of the vacuum distillation tower is 75-125°C, and the operating pressure is 0.5-1.1kPa absolute pressure. Specifically, the operating temperature of the tower bottom is 125°C, the operating pressure is 1.1kPa absolute pressure, and the operating temperature of the tower top is 75°C, and the operating pressure is 0.5kPa absolute pressure. The organic vapor entering the tower from the feed port of the vacuum distillation tower continuously condenses during the rising process, and the droplets fall into the tower bottom reboiler. After being heated by the tower bottom reboiler, a part of it becomes organic vapor again, and mass transfers with the falling droplets, and is discharged from the top of the vacuum distillation tower together with the uncondensed organic vapor. The organic vapor extracted from the gas phase outlet at the top of the vacuum distillation tower is condensed, and after condensation and cooling to 10°C, the condensate is returned to the vacuum distillation tower as a reflux liquid for reflux circulation. The reflux liquid and the organic vapor in the vacuum distillation tower are mass transferred in the vacuum distillation tower to reduce the TBP content in the rising organic vapor. After multiple cycles until the TBP content in the condensate drops to ≤0.02wt%, part of the condensate is extracted and sent to the kerosene receiving tank. This part of the condensate is the kerosene. The other part of the condensate continues to reflux. In this embodiment, the reflux ratio (i.e., the ratio of the condensate flow rate returned to the vacuum distillation tower (T1) to the condensate flow rate extracted to the kerosene receiving tank (V8)) is 2. The liquid remaining in the tower bottom reboiler is sampled, and when the TBP content is ≥80wt%, it is extracted by the tower bottom extraction pump. This part of the liquid is the TBP. The extracted TBP is cooled to 40°C by the TBP fraction cooler and then enters the TBP receiving tank. At the same time, a high-concentration TBP component is added to the outlet of the falling film evaporator separation chamber from the tower bottom reboiler to balance the stability of the liquid level at the bottom of the falling film evaporator heating chamber; and the vaporized gas phase in the falling film evaporator heating chamber is eluted and purified in the separation chamber.

[0128] Compared with the existing process conditions, the method for recovering radioactive organic waste liquid and the recovery device used in this embodiment can not only recover the organic solvent, but also greatly reduce the final disposal amount of radioactive organic waste liquid (the volume reduction ratio can reach 100:1), reduce the disposal difficulty and save the disposal and operation costs. This embodiment greatly reduces the temperature of the distillation system, realizes the recovery and reuse of tributyl phosphate (TBP) and kerosene in the radioactive organic waste liquid at a non-boiling temperature, avoids the thermal decomposition reaction of tributyl phosphate (TBP) with nitric acid, nitrates, etc. at high temperature, improves the safety of system operation and saves energy consumption. The volume reduction of radioactive organic waste liquid is achieved, and the volume reduction ratio reaches 100:1, reducing the amount of waste that needs to be treated later.

[0129] It is to be understood that the above embodiments are merely exemplary embodiments used to illustrate the principles of the present invention, but the present invention is not limited thereto. For those of ordinary skill in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. A method for recovering radioactive organic waste liquid, the radioactive organic waste liquid comprising: Tributyl phosphate, kerosene, radiolysis light products, radiolysis heavy products, radionuclides, insoluble aqueous phase, suspended matter, nitrates, nitric acid, water, characterized in that the recovery method comprises the following steps: 1) The radioactive organic waste liquid is first pretreated to remove the insoluble aqueous phase and suspended matter, and to elute the excess nitrate and nitric acid; 2) removing radiolysis light products, radionuclides and radiolysis heavy products to obtain vaporized organic steam, specifically: the pretreated radioactive organic waste liquid is sent to a liquid preheater, the liquid preheater is operated under the first heating temperature and the first pressure conditions, the radioactive organic waste liquid flows from top to bottom on the inner wall of the heating tube of the liquid preheater, the radiolysis light products and dissolved water and dissolved acid contained in the radioactive organic waste liquid are vaporized in the flow process, flow upstream, and are discharged from the top pipe port of the upper head of the liquid preheater, and after passing through the condenser cooler, the non-condensed steam is discharged to the vacuum system, the condensate is discharged into the light oil phase tank, the preheated radioactive organic waste liquid is sent to the falling film evaporator, and the falling film The evaporator is operated under the second heating temperature and the second pressure conditions, the radioactive organic waste liquid flows from top to bottom inside the heating tube of the falling film evaporator, kerosene and tributyl phosphate in the radioactive organic waste liquid are vaporized in the flow process, the vaporized organic vapor and the unvaporized liquid flow downward in parallel, and the gas enters the separation chamber of the falling film evaporator; the liquid enters the residual liquid circulation tank, and is sent back to the upper head circulating liquid inlet of the falling film evaporator by the residual liquid circulation pump, and circulates and evaporates, the radiolysis heavy products and radionuclides in the radioactive organic waste liquid remain in the unvaporized liquid phase and are discharged as residual liquid, and the vaporized organic vapor enters the vacuum distillation tower after the entrained droplets are separated in the separation chamber of the falling film evaporator; 3) The vaporized organic vapor is subjected to vacuum distillation treatment to separate tributyl phosphate and kerosene, specifically: the vacuum distillation tower is operated under the third temperature and third pressure conditions, the vaporized organic vapor entering the tower from the feed port of the vacuum distillation tower is continuously condensed in the process of rising, and the liquid droplets fall into the tower kettle reboiler, and after being heated by the tower kettle reboiler, a part of it is converted into organic vapor again, and mass transfer is carried out with the falling liquid droplets, and it is discharged from the top of the vacuum distillation tower together with the uncondensed organic vapor, and the organic vapor extracted from the gas phase outlet of the top of the vacuum distillation tower is condensed, and after condensing to a fourth temperature, the condensate is returned to the vacuum distillation tower as a reflux liquid for Reflux circulation, mass transfer occurs between the reflux liquid and the organic vapor in the vacuum distillation tower in the vacuum distillation tower, so that the content of tributyl phosphate in the rising organic vapor decreases. After multiple cycles until the content of tributyl phosphate in the condensate drops to the second concentration, part of the condensate is extracted, which is kerosene, and the other part of the condensate continues to reflux circulation, and the liquid remaining in the tower bottom reboiler is sampled. When the content of tributyl phosphate in the sample reaches the third concentration, the tower bottom extraction pump extracts the liquid, which is tributyl phosphate. The extracted tributyl phosphate is cooled by the tributyl phosphate fraction cooler and then enters the tributyl phosphate receiving tank. A stream of tributyl phosphate is added from the reboiler in the tower to the outlet of the separation chamber of the falling film evaporator to balance the stability of the liquid level at the bottom of the heating chamber of the falling film evaporator and to elute and purify the vaporized gas phase in the heating chamber of the falling film evaporator in the separation chamber of the falling film evaporator.

2. The method for recovering radioactive organic waste liquid according to claim 1, characterized in that: Step 1) is specifically as follows: in a mixing and clarifying tank, the radioactive organic waste liquid is stirred, mixed and clarified using a dilute nitric acid solution of a first concentration, and the insoluble aqueous phase, suspended matter and excess dissolved nitrate and nitric acid entrained in the radioactive organic waste liquid are eluted into the aqueous phase waste liquid for discharge and removal.

3. The method for recovering radioactive organic waste liquid according to claim 2, characterized in that: In the step 1), the first concentration is 0.01-0.02 mol / L; The first heating temperature in the step 2) is 80-110° C., and the first pressure is 4-8 kPa absolute pressure; The second heating temperature is 105-125° C., and the second pressure is 0.3-1.0 kPa absolute pressure.

4. The method for recovering radioactive organic waste liquid according to claim 2, characterized in that: The third temperature described in the step 3) includes: the third temperature at the top of the vacuum distillation tower is 60-75°C, and the third temperature at the bottom of the vacuum distillation tower is 100-125°C. The third pressure includes: the third pressure at the top of the vacuum distillation tower is an absolute pressure of 0.15-0.5kPa, and the third pressure at the bottom of the vacuum distillation tower is an absolute pressure of 0.4-1.1kPa.

5. The method for recovering radioactive organic waste liquid according to claim 2, characterized in that: The fourth temperature is 5-20° C., the second concentration is that the content of tributyl phosphate in the condensate is ≤0.02wt%, and the third concentration is that the content of tributyl phosphate in the sample is ≥80wt%.

6. The method for recovering radioactive organic waste liquid according to any one of claims 1 to 5, characterized in that: The radioactive organic waste liquid is the waste tributyl phosphate-kerosene mixed organic waste liquid produced by the nuclear fuel reprocessing plant.

7. A recovery device used in the method for recovering radioactive organic waste liquid according to any one of claims 1 to 6, characterized in that: include: The pretreatment unit is used to separate the insoluble aqueous phase and suspended matter in the radioactive organic waste liquid by sedimentation, and to elute nitrate and nitric acid; The radiolysis product separation unit is connected to the pretreatment unit. The radiolysis product separation unit is used to remove radiolysis light products, radionuclides and radiolysis heavy products. The radiolysis product separation unit includes: a feed liquid preheater (E1), a feed tank (V4), a feed pump (P3), a condenser cooler (E2), a light oil phase tank (V3), a falling film evaporator (E3), a residual liquid circulation tank (V6), a residual liquid circulation pump (P4), and a residual liquid tank (V5); The liquid preheater (E1) is connected to a pretreatment unit upstream, the outlet of the liquid preheater (E1) is connected to a feed tank (V4), the gas phase outlet of the upper head of the liquid preheater (E1) is connected to a condenser cooler (E2), the outlet of the condenser cooler (E2) is connected to a light oil phase tank (V3), and the non-condensable steam outlet of the condenser cooler (E2) is connected to a vacuum system; the feed tank (V4), the feed pump (P3), and the falling film evaporator (E3) are connected in sequence through pipelines; the falling film The liquid phase outlets of the heating chamber and the separation chamber of the evaporator (E3) are connected to the residual liquid circulation tank (V6), the outlet of the residual liquid circulation tank (V6) is connected to the residual liquid circulation pump (P4), and the outlet of the residual liquid circulation pump (P4) is respectively connected to the residual liquid tank (V5) and the circulating liquid inlet of the upper head of the falling film evaporator (E3) through pipelines; the gas phase outlet of the separation chamber of the falling film evaporator (E3) is connected to the tributyl phosphate and kerosene separation unit; and a sampling port (A3) is provided at the outlet of the residual liquid circulation pump (P4); The pretreated organic waste liquid enters the liquid preheater (E1) for preheating, removes the radiolysis light products and at least the preset content of dissolved water and dissolved acid, and enters the falling film evaporator (E3) heating chamber for cyclic evaporation. The radioactive nuclides and the radiolysis heavy products remain in the liquid phase. The purified organic vapor is discharged from the gas phase outlet of the separation chamber and enters the tributyl phosphate and kerosene separation unit. The falling film evaporator (E3) comprises: a heating chamber and a separation chamber, wherein the material is fed into the falling film evaporator from the upper part of the heating chamber, flows down in a film-like manner along the inner wall of the heat exchange tube in the heating chamber and is partially vaporized along the tube path, a part of the material not vaporized in the heating chamber is circulated and fed into the inlet of the falling film evaporator (E3), and the rest is discharged as residual liquid; the vaporized material is sucked into the gas phase separation chamber of the falling film evaporator by the downstream vacuum; a filler and a liquid distributor are arranged on the top of the separation chamber for purifying the radioactive nuclides and radiolysis products entrained in the separation chamber, and the liquid distributor is arranged above the filler; The tributyl phosphate and kerosene separation unit is connected to the radiolysis product separation unit. The tributyl phosphate and kerosene separation unit is used to perform vacuum distillation treatment on the organic solvent treated by the radiolysis product separation unit to separate it into tributyl phosphate and kerosene. The tributyl phosphate and kerosene separation unit includes: a vacuum distillation tower (T1), a tower bottom reboiler (E4), a tower bottom extraction pump (P5), a tributyl phosphate fraction cooler (E6), a tributyl phosphate receiving tank (V9), a tower top condenser cooler (E5), a gas-liquid separation tank (F1), a tower top reflux tank (V7), a tower top reflux pump (P6), and a kerosene receiving tank (V8); The feed inlet of the vacuum distillation tower (T1) is connected to the gas phase outlet of the radiolysis product separation unit; the gas phase outlet of the top of the vacuum distillation tower (T1), the top condenser cooler (E5), the top reflux tank (V7), and the top reflux pump (P6) are connected in sequence through pipelines; the non-condensable steam outlet of the top condenser cooler (E5) is connected to the gas-liquid separation tank (F1), and the gas phase outlet of the gas-liquid separation tank (F1) is connected to the vacuum system; the liquid phase outlet of the gas-liquid separation tank (F1) is connected to the top reflux tank (V7); the outlet of the top reflux pump (P6) is connected to the reflux port of the vacuum distillation tower (T1) and the kerosene receiving tank (V8), and the top reflux pump A sampling port (A1) is provided on the connecting pipeline between the outlet of the vacuum distillation tower (T1) and the kerosene receiving tank (V8); the lower outlet of the tower kettle of the vacuum distillation tower (T1), the tower kettle reboiler (E4), the tower kettle extraction pump (P5), the tributyl phosphate fraction cooler (E6), and the tributyl phosphate receiving tank (V9) are connected in sequence through pipelines; the gas phase outlet of the tower kettle reboiler (E4) is connected to the tower kettle of the vacuum distillation tower (T1); the outlet pipeline of the tower kettle extraction pump (P5) is provided with a branch and is connected to the radiolysis product separation unit; a sampling port (A2) is provided on the connecting pipeline between the tributyl phosphate fraction cooler (E6) and the tributyl phosphate receiving tank (V9); The gas phase outlet at the top of the vacuum distillation tower (T1) is connected to the top condenser cooler (E5). The produced kerosene vapor is condensed and cooled and flows to the top reflux tank (V7) by gravity. A part of it is returned to the tower as reflux liquid by the top reflux pump (P6), and the rest enters the kerosene receiving tank (V8); the production outlet of the tower bottom reboiler (E4) is connected to the tower bottom production pump (P5), and the produced TBP enters the TBP receiving tank (V9) or returns to the liquid phase feed port at the upper end of the falling film evaporator after passing through the TBP fraction cooler (E6).

8. The recovery device used in the method for recovering radioactive organic waste liquid according to claim 7, characterized in that: The pretreatment unit includes: a liquid receiving tank (V1), a liquid delivery pump (P1), a mixing and clarifying tank (V2), and a discharge pump (P2). The liquid receiving tank (V1), the liquid delivery pump (P1), the mixing and settling tank (V2), and the discharge pump (P2) are sequentially connected through pipelines, and the outlet of the discharge pump (P2) is connected to the radiolysis product separation unit; The radioactive organic waste liquid is mixed, stirred and clarified in a mixing and clarifying tank (V2) to remove the insoluble water phase and suspended matter and reduce the salt and acid content.

9. The recovery device used in the method for recovering radioactive organic waste liquid according to claim 8, characterized in that: The mixing and settling tank (V2) is a two-stage mixing and settling tank, in which the flow ratio of the organic phase to the dilute acid is (10-20):

1.

10. The recovery device used in the method for recovering radioactive organic waste liquid according to claim 7, characterized in that: The vacuum distillation tower (T1) is a vacuum packed distillation tower, and the vacuum distillation tower (T1) comprises: a distillation separation zone (T1-1) and a stripping separation zone (T1-2). The stripping separation zone (T1-2) is arranged above the distillation separation zone (T1-1), and the tower columns in each zone are connected by flanges. The separation stages of the distillation separation zone (T1-1) are 3 to 8, and the separation stages of the stripping separation zone (T1-2) are 1 to 5.

11. The recovery device used in the method for recovering radioactive organic waste liquid according to any one of claims 7 to 10, characterized in that: The feeding of radioactive organic waste liquid is continuous, the light products of radiolysis are continuously produced, and kerosene, tributyl phosphate and heavy products of radiolysis are continuously or intermittently produced.

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