JP3749041B2 - Extraction device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an extraction apparatus. More specifically, the present invention relates to an extraction apparatus that performs extraction by bringing a heavy liquid and a light liquid, such as a liquid metal and a molten salt, having a large specific gravity difference into contact with each other so that they do not suspend even when mixed and stirred. is there.
[0002]
[Prior art]
As a reprocessing of spent nuclear fuel, research is being conducted on the use of molten salt to separate and recover uranium and transuranium elements from other fission products. In this method, after dissolving uranium or a transuranium element as a compound such as chloride in a molten salt such as eutectic lithium chloride-potassium chloride, the molten salt is contacted with a liquid metal such as liquid cadmium or liquid bismuth, By adding a reducing agent such as metallic lithium, uranium and transuranium elements are selectively reduced and extracted into a liquid metal, while other fission products remain in the molten salt, thereby allowing uranium and transuranium to be extracted. Separation of elements and other fission products.
[0003]
As an extraction device used for such treatment, stirring is carried out in the extraction tank until a chemical equilibrium between the molten salt phase and the liquid metal phase is achieved, and after the equilibrium is reached, both phases are separated and the respective liquid phases are separated. There is a batch type that transfers to the next extraction tank.
[0004]
Further, a centrifugal extractor has been proposed as a continuous extractor that continues to flow each phase to the next extractor at a constant flow rate while stirring in the extractor. The extraction tank of the centrifugal extraction apparatus is composed of a hollow rotor that rotates at high speed and a housing that accommodates the hollow rotor. The molten salt phase and the liquid metal phase introduced between the housing and the hollow rotor are separated by the high-speed rotational force of the hollow rotor. Stir. The stirred molten salt phase and liquid metal phase are sucked into the hollow rotor from the inlet at the bottom of the hollow rotor, and separated in the radial direction by the centrifugal force in the hollow rotor. Two discharge ports are provided in the upper part of the hollow rotor. Liquid metal as a heavy liquid is discharged from the discharge port provided on the radially outer side, and light liquid is discharged from the discharge port provided on the radially inner side. The molten salt is discharged. The two discharge ports are connected to different ports, and since the heights at which the two ports are provided are different, both phases are surely separated and discharged.
[0005]
By the way, since the melting point of metals and salts used for separation of uranium and transuranium elements is about 300 to 350 ° C., in order to ensure sufficient fluidity and solubility of solutes, the extraction device is set to about 500 ° C. It is necessary to operate in an atmosphere. Further, if oxygen, moisture, nitrogen, or the like is present in the atmosphere in which the extraction is performed, the reaction with the solute causes a recovery loss, and thus it is necessary to operate the extraction apparatus in an inert gas such as argon gas. That is, in the extraction process described above, it is necessary to handle the molten salt and the liquid metal in a high temperature and inert atmosphere.
[0006]
[Problems to be solved by the invention]
However, neither the batch type extraction device nor the centrifugal extraction device is suitable for performing the treatment in a high temperature and inert atmosphere. That is, in the batch type extraction apparatus, it is necessary to completely separate the molten salt phase and the liquid metal phase after the stirring is stopped, and to transfer each separately to the next extraction tank. It is difficult to do in it. Further, in the centrifugal extraction device, it is necessary to rotate the hollow rotor at a high speed, but it is difficult to realize a mechanism for rotating the hollow rotor at a high temperature in an inert atmosphere.
[0007]
Further, in the centrifugal extraction device, operating conditions (such as the number of revolutions of the hollow rotor and the supply flow rates of both liquid phases) for reliably separating the molten salt phase and the liquid metal phase and discharging them from separate discharge ports are strict. If the supply of molten salt or liquid metal is cut off due to a pump failure, the liquid phase may be lost from the extraction tank or a different liquid phase may be mixed into the discharge port. Inferior.
[0008]
An object of the present invention is to provide an extraction device that is suitable for operation in a high temperature and inert atmosphere and can reliably separate both phases.
[0009]
[Means for Solving the Problems]
In order to achieve this object, the invention according to claim 1 is an extraction apparatus that performs extraction while bringing a light liquid and a heavy liquid into contact with each other into contact with each other. A heavy liquid transfer passage that is connected to a portion lower than the interface between the light liquid phase and the heavy liquid phase of the extraction tank and then flows out after the heavy liquid is guided to a first height higher than the connection portion; A light liquid transfer passage that is connected to a portion higher than the interface between the light liquid phase and the heavy liquid phase and that flows after the light liquid is guided to a second height higher than the connection portion, and a heavy liquid in the extraction tank. A heavy liquid supply means for supplying the heavy liquid in the extraction tank to overflow from the heavy liquid transfer passage, and a light liquid for supplying the light liquid in the extraction tank to overflow the light liquid in the extraction tank from the light liquid transfer passage. Liquid supply means, and the heavy liquid transfer passage guides the liquid level of the heavy liquid in the extraction tank to the first height by guiding the heavy liquid to the first height. Is allowed, the light liquid flow passage is made to correspond to the liquid level of the second height of the light liquid extraction tank by directing a light liquid to the second height.
[0010]
Therefore, the heavy liquid supplied from the heavy liquid supply means and the light liquid supplied from the light liquid supply means come into contact with each other in the extraction tank to perform extraction. At this time, it is preferable that the two liquids are in countercurrent contact in order to increase the extraction efficiency, and it is more preferable that the heavy liquid and the light liquid are introduced to face each other near the interface. There is a large difference in specific gravity between light and heavy liquids that are two phases, and both phases do not mix. Therefore, only heavy liquid flows into the heavy liquid transfer passage, and only light liquid flows into the light liquid transfer passage. Since the heavy liquid transfer passage lifts the heavy liquid to the first height and then flows it out, the height (liquid level) of the heavy liquid in the extraction tank corresponds to the first height. Similarly, since the light liquid transfer passage lifts the light liquid to the second height and then flows out, the light liquid height (liquid level) in the extraction tank corresponds to the second height. That is, an amount of heavy liquid corresponding to the amount newly supplied from the heavy liquid supply means is transferred so as to overflow from the extraction tank through the heavy liquid transfer passage, and is newly supplied from the light liquid supply means. The amount of light liquid corresponding to the amount of liquid is transferred from the extraction tank so as to overflow through the light liquid transfer passage.
[0011]
Moreover, the extraction apparatus of Claim 2 equips an extraction tank with a stirring means. Therefore, the heavy liquid and the light liquid in the extraction tank are agitated to promote extraction. Since the density difference between the heavy liquid and the light liquid is not large, the heavy liquid and the light liquid do not suspend even if agitated, and the light liquid does not enter the heavy liquid transfer passage and the heavy liquid does not enter the light liquid transfer passage.
[0012]
In the extraction device according to claim 3, a plurality of extraction tanks are provided, and a heavy liquid is introduced into a next extraction tank from a portion lower than the interface between the light liquid phase and the heavy liquid phase of one extraction tank. A liquid side connection passage and a light liquid side connection passage that guides the light liquid from a portion higher than the interface between the light liquid phase and the heavy liquid phase of one extraction tank to the next extraction tank are provided. Therefore, heavy liquid is sent through the heavy liquid side connection passage and light liquid is sent through the light liquid side connection passage to the first stage extraction tank → second stage extraction tank →. Become.
[0013]
In the extraction device according to claim 4, the light liquid is a molten salt and the heavy liquid is a liquid metal. In the process of reprocessing spent nuclear fuel, it has been studied to dissolve fission products in molten salt and selectively extract uranium and transuranium elements from the molten salt into liquid metal. An extraction apparatus suitable for this extraction can be provided.
[0014]
Further, in the extraction device according to claim 5, the heavy liquid supply means supplies heavy liquid into the extraction tank from the heavy liquid tank disposed at a position higher than the first height by using gravity, A supply means supplies a light liquid in an extraction tank using gravity from the light liquid tank arrange | positioned in the position higher than 2nd height. For example, when it is necessary to operate in a high temperature and inert atmosphere, this atmosphere may not be suitable for the use of a pump or the like. Thus, even if it is a case where use of a pump etc. is not suitable as a means to supply a heavy liquid and a light liquid, a heavy liquid and a light liquid can be reliably supplied in an extraction tank.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the configuration of the present invention will be described in detail based on the best mode shown in the drawings.
[0016]
FIG. 1 shows an example of an embodiment of an extraction apparatus to which the present invention is applied. The extraction device performs the extraction while bringing the light liquid 1 and the heavy liquid 2 into contact with each other. The extraction tanks 3 and 4 for bringing the light liquid 1 and the heavy liquid 2 into contact with each other, A heavy liquid transfer passage 5 connected to a portion lower than the interface 9 between the liquid phase and the heavy liquid phase and guiding the heavy liquid 2 to a first height H1 higher than the connection portion and then flowing out, and an extraction tank 3, A light liquid transfer passage 6 connected to a portion higher than the interface 9 between the light liquid phase and the heavy liquid phase 4 and guided to the second height H2 higher than the connection portion and then discharged, and extraction A heavy liquid supply means 7 for supplying the heavy liquid 2 into the tank 3 and causing the heavy liquid 2 in the extraction tank 4 to overflow from the heavy liquid transfer passage 5, and a light liquid 1 for supplying the heavy liquid 2 into the extraction tank 4 3 is provided with a light liquid supply means 8 for allowing the light liquid 1 in the liquid 3 to overflow from the light liquid transfer passage 6, and the heavy liquid transfer passage 5 guides the heavy liquid 2 to the first height H1 to thereby extract the extraction tanks 3 and 4. The liquid level of the heavy liquid 2 corresponds to the first height H1, and the light liquid transfer passage 6 guides the light liquid 1 to the second height H2 so that the light liquid 1 in the extraction tanks 3 and 4 The liquid level is configured to correspond to the second height H2.
[0017]
Note that the two-phase light liquid 1 and heavy liquid 2 targeted by the extraction apparatus of the present invention have a large specific gravity difference so that they do not mix with each other and do not suspend even if stirred. For example, in this embodiment, the light liquid 1 is a molten salt and the heavy liquid 2 is a liquid metal. That is, this extraction device is used in a reprocessing process that selectively separates and recovers uranium and transuranium elements from spent nuclear fuel using the molten salt 1 and the liquid metal 2, and is dissolved in the molten salt 1. Uranium and transuranium elements are selectively reduced from fission products in spent nuclear fuel, extracted into liquid metal, and uranium and transuranium elements are separated from other fission products remaining in molten salt 1 Suitable for doing. Examples of the liquid metal 2 in this case include liquid cadmium and liquid bismuth. The molten salt 1 is eutectic lithium chloride-potassium chloride, for example. The specific gravity of the liquid metal 2 is, for example, about 8 to 10, and the specific gravity of the molten salt 1 is, for example, about 1 to 2. Therefore, the specific gravity difference between the light liquid 1 and the heavy liquid 2 is, for example, about 6 to 9.
[0018]
Although the present invention can be implemented even with one extraction tank, it is preferable to combine a plurality of tanks when continuous processing is performed. For example, in the present embodiment, two extraction tanks 3 and 4 are provided, and these are connected to the extraction tank 4 in the next stage from a portion lower than the interface 9 between the light liquid phase and the heavy liquid phase of the extraction tank 3. The liquid side connection passage 10 is communicated with the light liquid side connection passage 11 that guides the light liquid 1 from the portion higher than the interface 9 between the light liquid phase and the heavy liquid phase of the extraction tank 4 to the extraction tank 3 in the next stage. ing. That is, for the heavy liquid 2, the extraction tank 3 is the first stage and the extraction tank 4 is the second stage, and for the light liquid 1, the extraction tank 4 is the first stage and the extraction tank 3 is the second stage. Thereby, the heavy liquid 2 and the light liquid 1 can be made into countercurrent contact in each extraction tank 3 and 4. FIG.
[0019]
The heavy liquid side connection passage 10 is the same as the arbitrary position of the heavy liquid phase of the first extraction tank 3, for example, the arbitrary position of the heavy liquid phase of the second extraction tank 4 from the bottom, for example, the heavy liquid supply means 7. The heavy liquid 2 is led near the interface 9. Thereby, the heavy liquid 2 is discharged from a portion as far as possible from the interface 9 of the first extraction tank 3 and the heavy liquid 2 is supplied to a portion of the second extraction tank 4 as close to the interface 9 as possible. In addition, the extraction efficiency in the extraction tanks 3 and 4 can be increased and more reliably separated and recovered. Similarly, the light liquid side connection passage 11 is provided at an arbitrary position of the light liquid phase of the first extraction tank 4, for example, an arbitrary position of the light liquid phase of the second extraction tank 3 from the vicinity of the upper portion, for example, a light liquid supply means. As with 8, the light liquid 1 is led near the interface 9. Thus, the light liquid 1 is discharged from a portion as far as possible from the interface 9 of the first extraction tank 4 and the light liquid 1 is supplied to a portion of the second extraction tank 3 as close to the interface 9 as possible. In addition, the extraction efficiency in the extraction tanks 3 and 4 can be increased and more reliably separated and recovered. By supplying two liquids in the vicinity of the interface 9, the deviation from the chemical equilibrium in the vicinity of the interface 9 becomes large, and the extraction reaction is promoted to improve the extraction efficiency.
[0020]
For example, as shown in FIG. 2, the heavy liquid supply means 7 supplies the heavy liquid 2 into the extraction tank 3 using gravity from the heavy liquid tank 12 disposed at a position higher than the first height H1. Is. A flow control valve 14 is provided in the middle of the heavy liquid supply passage 13 that guides the heavy liquid 2 in the heavy liquid tank 12 to the first extraction tank 3. Further, the heavy liquid supply passage 13 is connected to a portion close to the interface 9 of the first extraction tank 3.
[0021]
For example, as shown in FIG. 3, the light liquid supply means 8 supplies the light liquid 1 into the extraction tank 4 using gravity from a light liquid tank 15 disposed at a position higher than the second height H2. Is. A flow control valve 17 is provided in the middle of the light liquid supply passage 16 that guides the light liquid 1 in the light liquid tank 15 to the first extraction tank 4. The light liquid supply passage 16 is connected to a location near the interface 9 of the first extraction tank 4.
[0022]
The heavy liquid transfer passage 5 is connected to a part, for example, the bottom part, away from the interface 9 of the second extraction tank 4, and the heavy liquid 2 flows out from this part. The downstream end 5a of the heavy liquid transfer passage 5 rises to the first height H1 and is connected to the heavy liquid recovery tank 18.
[0023]
The light liquid transfer passage 6 is connected to a part away from the interface 9 of the extraction tank 3 in the second stage, for example, near the upper part, and the light liquid 1 flows out from this position. The downstream end 6a of the light liquid transfer passage 6 rises to the second height H2 and is connected to the light liquid recovery tank 19.
[0024]
Stirring means 20 is provided in the extraction tanks 3 and 4. As the stirring means 20, for example, a stirring blade 21 rotated by a motor (not shown) or an inert gas 23 such as argon gas that does not react with the heavy liquid 2 and the light liquid 1 is blown from the nozzle 22 to the bottom of the heavy liquid phase. It is conceivable that the heavy liquid 2 and the light liquid 1 are agitated by the buoyancy (air lift force) of 23. When the stirring blade 21 is used as the stirring means 20, the stirring blade 21 is rotated at about 100 to 200 rpm. If the rotation speed is in this range, the stirring blade 21 can be rotated by using a motor or the like even in a high temperature and inert atmosphere. Also, the molten salt 1 and the liquid metal 2 can be improved with this rotation speed. Can be stirred. In the present embodiment, the stirring blade 21 is installed at the interface between the heavy liquid 2 and the light liquid 1 and is provided so as to promote the mixing of the two liquids. In the case of the embodiment, even if the stirring blade 21 is provided on the phase side of the liquid metal 2 to stir the extraction solvent phase, the extraction efficiency can be improved. In other words, it is effective to stir the interface 9 to promote extraction in the molten salt / liquid metal system, and in the molten salt / liquid metal system, even if the interface 9 is stirred, both phases are too mixed and suspended. Experiments have confirmed that no turbid phenomenon is observed. For this reason, a stirring blade 21 is provided at the interface 9, but in the case of placing importance on the separability rather than the extraction speed other than the molten salt / liquid metal system, the inside of both phases is separately stirred by avoiding the interface 9. You may make it do. In the extraction apparatus of FIG. 1, the extraction tank 4 is provided with the stirring means 20 using the stirring blade 21, and the extraction tank 3 is provided with the stirring means 20 using the nozzle 22 and the gas 23. Of course, the same stirring means 20 may be provided in the tanks 3 and 4.
[0025]
It should be noted that the upstream ends 5b and 10a of the heavy liquid transfer passage 5 and the heavy liquid side connection passage 10 are not mixed with the light liquid 1 even when the light liquid 1 and the heavy liquid 2 are stirred by the stirring means 20. It is connected to a portion of the extraction tanks 3 and 4 away from the interface 9. Further, the upstream ends 6b and 11a of the light liquid transfer passage 6 and the light liquid side connection passage 11 are such that the heavy liquid 2 is not mixed even when the light liquid 1 and the heavy liquid 2 are stirred by the stirring means 20. It is connected to a portion of the extraction tanks 3 and 4 away from the interface 9. Depending on the specific gravity difference between the light liquid 1 and the heavy liquid 2, the stirring method, the stirring strength, etc., the light liquid 1 is a molten salt and the heavy liquid 2 is a liquid metal, or the light liquid 1 is water. For example, when the heavy liquid 2 is a liquid metal, the upstream ends 5b, 6b, 10a, 11a of the passages 5, 6, 10, 11 are connected to a portion at least 2 to 3 cm away from the interface 9, for example. You can do it.
[0026]
Next, the operation of the extraction device will be described.
[0027]
This extraction device selectively extracts uranium and transuranium elements in the molten salt 1 to the liquid metal 2 side while the molten salt 1 and the liquid metal 2 are in countercurrent contact. The extraction apparatus is operated in a high-temperature and inert gas atmosphere in order to prevent fluidity of the molten salt 1 and the liquid metal 2 and oxidization of the solute. The liquid metal 2 in the heavy liquid tank 12 is supplied to the first extraction tank 3 from the heavy liquid supply passage 13 and is stirred by the stirring means 20 while being in contact with the molten salt 1 in the interface portion where the uranium in the molten salt 1 and The transuranium element is eluted into the liquid metal 2 and separated and recovered (extraction), and then flows into the second extraction tank 4 through the heavy liquid side connection passage 10. In the second extraction tank 4, extraction is performed at the interface portion where the molten salt 1 and the liquid metal 2 contact while being stirred by the stirring means 20, and then flows out through the heavy liquid transfer passage 5 to recover the heavy liquid. It is collected in the tank 18. Since the liquid metal 2 does not flow to the heavy liquid recovery tank 18 side unless the first height H1 of the heavy liquid transfer passage 5 is exceeded, the height (liquid level) of the heavy liquid 2 in the extraction tanks 3 and 4 is This corresponds to the first height H1. That is, the overflow with respect to the first height H1 overflows to the heavy liquid recovery tank 18 side and is recovered. Therefore, after the liquid level of the liquid metal phase in the extraction tanks 3 and 4 reaches the first height H1, the same amount of the liquid metal 2 as that supplied from the heavy liquid supply means 7 is in the first stage. It flows from the extraction tank 3 → the heavy liquid side connection passage 10 → the second extraction tank 4 → the heavy liquid transfer passage 5 → the heavy liquid recovery tank 18.
[0028]
On the other hand, the molten salt 1 in the light liquid tank 15 is supplied to the first extraction tank 4 from the light liquid supply passage 16 and causes an interfacial reaction at a portion in contact with the liquid metal 2 while being stirred by the stirring means 20. Then, it flows into the extraction tank 3 at the second stage through the light liquid side connection passage 11. In the second extraction tank 3, extraction is performed at the interface portion that is in contact with the liquid metal 2 while being stirred by the stirring means 20, and then flows out through the light liquid transfer passage 6 and is recovered in the light liquid recovery tank 19. The Since the molten salt 1 does not flow to the light liquid recovery tank 19 side unless the second height H2 of the light liquid transfer passage 6 is exceeded, the height (liquid level) of the molten salt 1 in the extraction tanks 3 and 4 is This corresponds to the second height H2. That is, the overflow of the second height H2 overflows to the light liquid recovery tank 19 and is recovered. Therefore, after the liquid level of the molten salt phase in the extraction tanks 3 and 4 reaches the second height H2, the same amount of the molten salt 1 as that supplied from the light liquid supply means 8 becomes the first stage. It flows from the extraction tank 4 to the light liquid side connection passage 11 → the second extraction tank 3 → the light liquid transfer passage 6 → the light liquid recovery tank 19.
[0029]
In this way, uranium and transuranium elements in the molten salt 1 can be extracted to the liquid metal 2 side simply by supplying the liquid metal 2 and the molten salt 1 and performing stirring by the stirring means 20. That is, the extraction process can be performed without using advanced techniques or special operations such as rotating the hollow rotor with high precision and high speed as in the case of using a centrifugal extraction device. In addition, since the stationary time of both phases is not required as in the case of using a batch type extraction device, it becomes possible to perform processing quickly and continuously, as well as phase separation and separation phase transfer. You can save time and effort.
[0030]
Further, since the flow rate in the extraction device is determined by the supply amounts of the liquid metal 2 and the molten salt 1, the processing amount can be easily controlled. That is, in the centrifugal extractor, the flow of both phases is generated by the centrifugal force of the hollow rotor, making it difficult to control the flow rate. However, in this extractor, the amount of residence in the extraction tanks 3 and 4 is constant. The flow rate can be controlled by adjusting the amount, and it becomes easy to handle as an extraction device. In this case, since the supply amount of the liquid metal 2 and the supply amount of the molten salt 1 can be adjusted separately, the extraction process can be controlled more easily.
[0031]
In the centrifugal extraction device, when the supply of the liquid metal 2 or the molten salt 1 is stopped for some reason, the liquid in the housing or the hollow rotor is lost, and the supply of one of the two phases is stopped. In such a case, a situation in which the other liquid flows out from the discharge port on one side occurs, but such a situation does not occur in the present extraction device.
[0032]
Moreover, in this extraction apparatus, since the heavy liquid tank 12 and the light liquid tank 15 are arrange | positioned in the high place, the heavy liquid 2 and the light liquid 1 can be supplied using gravity. This eliminates the need for a pumping means such as a pump, simplifies the apparatus, and causes the extraction of heavy liquid 2 and light liquid 1 in a high temperature and inert atmosphere where the pump is difficult to use. Processing can be performed.
[0033]
The above-described embodiment is an example of a preferred embodiment of the present invention, but is not limited thereto, and various modifications can be made without departing from the scope of the present invention. For example, although the above-described extraction device includes two extraction tanks 3 and 4, the number of extraction tanks may be three or more, or may be one. Even in the case of one, extraction is performed by stirring while the heavy liquid 2 and the light liquid 1 are in countercurrent contact. When two or more extraction tanks are connected, the heavy liquid transfer passage 5 and the light liquid transfer path 6 may be provided in the extraction tanks as final stages of the heavy liquid 2 and the light liquid 1, respectively. Therefore, when the heavy liquid 2 and the light liquid 1 are not flown in countercurrent contact, for example, in the case of cocurrent contact, the heavy liquid transfer passage is connected to the same extraction tank as the final stage of each of the heavy liquid and the light liquid. 5 and a light liquid transfer passage 6 may be provided.
[0034]
In the above-described extraction apparatus, the heavy liquid 2 is a liquid metal and the light liquid 1 is a molten salt. However, the extraction apparatus is not limited to such a molten salt / liquid metal system, and is not suspended when stirred. If the heavy liquid 2 and the light liquid 1 have a large specific gravity difference, for example, a water / liquid metal system or an organic / liquid metal system may be used. Since the specific gravity of water is about 1 and the specific gravity of the organic phase is around 1, the difference in specific gravity is about 7 to 9 in both cases. Will not be mixed.
[0035]
The specific gravity difference between the light liquid 1 and the heavy liquid 2 may be about 5 or more, for example. It has been confirmed that even a water / liquid gallium system using liquid gallium having a specific gravity of about 6 as the liquid metal 2 can prevent such contamination. However, the upstream ends 5b, 10a, 6b, and 11a of the heavy liquid transfer passage 5, the heavy liquid side connection passage 10, the light liquid transfer passage 6, and the light liquid side connection passage 11 are connected to portions sufficiently separated from the interface 9. For example, the specific gravity difference between the light liquid 1 and the heavy liquid 2 may be less than about 5.
[0036]
In the above description, the case where uranium or transuranium element is selectively reduced and extracted into the liquid metal 2 from the fission product element in the spent fuel has been described as an example. However, uranium or transuranium element is not necessarily used. However, the present invention is not limited to the case where the element is extracted, but can be applied as long as the element dissolved in the molten salt 1 is extracted into the liquid metal 2, and conversely, the element dissolved in the liquid metal 2 is applicable. It is also applicable to the case of extracting from the molten salt 1.
[0037]
In the above description, the light liquid 1 is a molten salt and the heavy liquid 2 is a liquid metal. However, the light liquid 1 and the heavy liquid 2 have a large specific gravity difference so that they are not mixed and suspended even if stirred. As long as the heavy liquid 2 and the light liquid 1 can be separately collected from the heavy liquid transfer path 5 and the light liquid transfer path 6 without being mixed, it is not limited to the molten salt or the liquid metal. The liquid 2 and the light liquid 1 can also be applied.
[0038]
In the above description, the agitation unit 20 is provided. However, for example, the agitation unit 20 may be omitted when extraction can be sufficiently performed without agitation. For example, in the case of the first stage extraction tank 3 on the heavy liquid 2 side, when the heavy liquid 2 is supplied from a portion higher than the interface 9 to the light liquid phase and brought into countercurrent contact in the vertical direction in the extraction tank, The stirring means 20 may be omitted. In this case, it is desirable to connect the light liquid side connection passage 11 to a part sufficiently higher than the supply part of the heavy liquid 2 and discharge the light liquid 1 from this height.
[0039]
Further, in the above description, the heavy liquid supply means 7 and the light liquid supply means 8 are configured to supply the heavy liquid 2 and the light liquid 1 using gravity, but a pumping means such as a pump can be used. A pump or the like may be used under the conditions.
[0040]
【The invention's effect】
As described above, according to the extraction device of claim 1, when the specific gravity difference between the two phases to be extracted is large and does not mix with each other, the discharge port for transferring the heavy liquid in the extraction tank is set to both phases. Since the discharge port for transferring the light liquid is provided at a position higher than the interface of both phases, even if the light liquid and the heavy liquid are brought into contact with each other, the discharge port for transferring the light liquid is provided at a position higher than the interface of both phases. It is possible to prevent heavy liquid from being mixed into the light liquid discharge port and light liquid from being mixed into the heavy liquid discharge port. That is, a light liquid and a heavy liquid can be collected separately using a specific gravity difference while performing extraction.
[0041]
In addition, the liquid level of the heavy liquid in the extraction tank corresponds to the first height of the heavy liquid transfer passage, and the liquid level of the light liquid corresponds to the second height of the light liquid transfer passage. The amount of heavy liquid corresponding to the amount newly supplied from the means is transferred so as to overflow from the extraction tank through the heavy liquid transfer passage, and the amount corresponding to the amount newly supplied from the light liquid supply means. The light liquid is transferred from the extraction tank so as to overflow through the light liquid transfer passage. Therefore, it becomes possible to control the processing amount by adjusting the supply amounts of the heavy liquid supply means and the light liquid supply means, and the adjustment of the supply amounts of the heavy liquid supply means and the light liquid supply means is relatively simple. Therefore, the extraction device can be easily controlled. Furthermore, since these are separated and collected separately using the specific gravity difference between the light and heavy liquids, no special operation is required to separate or collect the light and heavy liquids. It is possible to provide an extraction apparatus suitable for operation in a conditionally severe high temperature and inert gas atmosphere.
[0042]
Moreover, in the extraction apparatus of Claim 2, since the stirring means is provided in the extraction tank, extraction can be promoted. Even in this case, the heavy liquid and the light liquid are not mixed and there is a specific gravity difference to such an extent that the heavy liquid and the light liquid do not suspend even if stirred, so that the mixing of the heavy liquid and the light liquid can be prevented.
[0043]
Further, in the extraction apparatus according to claim 3, a plurality of extraction tanks are provided, and a heavy liquid is introduced into a next extraction tank from a portion lower than the interface between the light liquid phase and the heavy liquid phase of one extraction tank. Since it is equipped with a liquid side connection passage and a light liquid side connection passage that guides the light liquid from a part higher than the interface between the light liquid phase and the heavy liquid phase of one extraction tank to the next extraction tank, the extraction device is multistage. Can be an expression.
[0044]
In the extraction device according to claim 4, the light liquid is a molten salt and the heavy liquid is a liquid metal. In the spent nuclear fuel reprocessing process, it has been studied that fission products are dissolved in a molten salt and uranium and transuranium elements are selectively extracted from the molten salt into a liquid metal. An extraction apparatus suitable for this extraction can be provided.
[0045]
Furthermore, in the extraction apparatus according to claim 5, the heavy liquid supply means supplies heavy liquid into the extraction tank using gravity from a heavy liquid tank disposed at a position higher than the first height, A supply means supplies a light liquid in an extraction tank using gravity from the light liquid tank arrange | positioned in the position higher than 2nd height. For example, when it is necessary to operate in a high temperature and inert atmosphere, it may be difficult to use a pump or the like. Thus, even when it is difficult to use a pump or the like as means for supplying heavy liquid or light liquid, heavy liquid and light liquid can be reliably supplied into the extraction tank.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram showing an example of an embodiment of an extraction apparatus of the present invention.
FIG. 2 is a schematic configuration diagram showing a heavy liquid supply unit of the extraction apparatus.
FIG. 3 is a schematic configuration diagram showing a light liquid supply means of the extraction apparatus.
[Explanation of symbols]
1 Molten salt (light liquid)
2 Liquid metal (heavy liquid)
3, 4 Extraction tank
5 Heavy liquid transfer passage
6 Light liquid transfer passage
7 Heavy liquid supply means
8 Light liquid supply means
9 Interface
10 Heavy liquid side connection passage
11 Light liquid side connection passage
12 Heavy liquid tank
15 Light liquid tank
20 Stirring means
H1 first height
H2 second height

Claims (5)

In an extraction apparatus that performs extraction while bringing a light liquid and a heavy liquid into contact with each other, an extraction tank for extracting the light liquid and the heavy liquid in contact with each other, and an interface between the light liquid phase and the heavy liquid phase of the extraction tank A heavy liquid transfer passage that is connected to a low part and flows out after guiding the heavy liquid to a first height higher than the connection part, and a part that is higher than the interface between the light liquid phase and the heavy liquid phase of the extraction tank To the second height higher than the connection site, the light liquid transfer passage that flows out after the light liquid is guided, and the heavy liquid in the extraction tank A heavy liquid supply means for overflowing the heavy liquid transfer passage; and a light liquid supply means for supplying a light liquid into the extraction tank and causing the light liquid in the extraction tank to overflow from the light liquid transfer path, The liquid transfer passage guides the heavy liquid to the first height so that the liquid level of the heavy liquid in the extraction tank corresponds to the first height. The light liquid transfer passage extraction device, characterized in that to adapt the level of the light liquid in the extraction vessel to the second height by directing the light liquid to said second height. The extraction apparatus according to claim 1, further comprising a stirring unit in the extraction tank. A plurality of the extraction tanks are provided, and these include a heavy liquid side connection passage for introducing the heavy liquid from a portion lower than the interface between the light liquid phase and the heavy liquid phase of the one extraction tank to the next extraction tank, 3. The light liquid side connection passage for guiding the light liquid from a portion higher than the interface between the light liquid phase and the heavy liquid phase of the extraction tank to the next extraction tank. Extraction device. The extraction device according to any one of claims 1 to 3, wherein the light liquid is a molten salt, and the heavy liquid is a liquid metal. The heavy liquid supply means supplies heavy liquid into the extraction tank using gravity from a heavy liquid tank disposed at a position higher than the first height, and the light liquid supply means includes the second liquid supply means. The extraction apparatus according to any one of claims 1 to 4, wherein a light liquid is supplied into the extraction tank by utilizing gravity from a light liquid tank disposed at a position higher than the height of the extraction tank.

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