Disclosure of Invention
The invention aims to solve the technical problem of providing a continuous supercritical extraction reaction kettle, equipment and an extraction method aiming at the defects in the prior art.
In order to solve the technical problems, the invention adopts the following technical scheme: the continuous supercritical extraction reaction kettle comprises a kettle body, a feed pipe arranged at the top of the kettle body and a slag outlet arranged at the bottom of the kettle body, wherein the top and the bottom of the kettle body are respectively provided with a feeding mechanism and a continuous slag outlet mechanism;
the continuous slag discharging mechanism comprises a slag discharging outer box connected to the slag discharging hole, a sub slag inlet formed in the top of the slag discharging outer box and communicated with the slag discharging hole, a sub slag discharging hole formed in the bottom of the slag discharging outer box, a slag discharging inner box which can be arranged in the slag discharging outer box in a sliding mode along the horizontal direction, a slag discharging sealing plate connected to the outer side of the slag discharging inner box and a slag discharging driving mechanism used for driving the slag discharging inner box to slide in a reciprocating mode to switch back and forth between a slag feeding state and a slag discharging state, wherein the top and the bottom of the slag discharging inner box are opened to form an upper slag feeding opening and a lower slag discharging opening respectively;
in the slag inlet state, an upper slag inlet opening of the slag outlet inner box is communicated with the sub slag inlet, and a lower slag outlet opening is sealed by the bottom surface of the slag outlet outer box;
and in the slag discharging state, the lower slag discharging opening of the slag discharging inner box is communicated with the sub slag discharging opening, and the slag discharging sealing plate seals the sub slag inlet.
Preferably, the slag discharging driving mechanism is an electric push rod which is arranged in the slag discharging outer box and is positioned at the side part of the slag discharging inner box;
a slag discharging elastic sheet is further arranged on the outer wall of one side, opposite to the electric push rod, of the slag discharging inner box;
a slag discharging elastic sheet is further arranged on the outer wall of one side, opposite to the electric push rod, of the slag discharging inner box;
the sub slag discharging port is also connected with a sub slag discharging pipe;
the continuous slag discharging mechanism further comprises a protective shell, the slag discharging outer box is located inside the protective shell, a slag discharging outlet is formed in the bottom of the protective shell, and an outlet cover plate is arranged on the slag discharging outlet.
Preferably, the feeding mechanism comprises a feeding pipe arranged at the top of the kettle body in a communicating manner, a feeding outer box connected to the feeding pipe, a feeding inlet arranged at the top of the feeding outer box, a feeding outlet arranged at the bottom of the feeding outer box and communicated with the feeding pipe, a feeding inner box arranged inside the feeding outer box in a sliding manner along the horizontal direction, an upper feeding sealing plate and a lower feeding sealing plate connected to the outer side of the feeding inner box, and a feeding driving mechanism for driving the feeding inner box to slide horizontally in a reciprocating manner so as to switch back and forth between a feeding state and a discharging state, wherein the top and the bottom of the feeding inner box are opened to form an upper feeding opening and a lower discharging opening respectively;
a feeding elastic sheet is further arranged on the outer wall of one side, opposite to the feeding driving mechanism, of the lower feeding sealing plate;
in the feeding state, an upper feeding opening of the feeding inner box is communicated with the feeding inlet, the lower discharging opening is sealed by the bottom surface of the feeding outer box, and meanwhile, the lower feeding sealing plate seals the feeding pipe;
and in the unloading state, a lower discharging opening of the feeding inner box is communicated with the feeding outlet, and the upper feeding sealing plate seals the feeding inlet.
Preferably, the feeding inlet is communicated with a trumpet-shaped feeding container, and a feeding cover plate is arranged on the top opening of the feeding container.
Preferably, the bottom of the kettle body is provided with an extractant inlet pipe, and the top of the kettle body is provided with an extractant outlet pipe.
Preferably, the kettle body is further provided with a stirring mechanism, and the stirring mechanism comprises a frame arranged on the kettle body, a stirring motor arranged on the frame, a stirring shaft which is in driving connection with an output shaft of the stirring motor and stretches into the kettle body, and a plurality of stirring blades arranged on the stirring shaft.
Preferably, a plurality of ultrasonic transducers are arranged on the inner wall of the kettle body.
Preferably, a plurality of ultrasonic transducers are arranged on the stirring blade or the stirring shaft.
Preferably, the kettle body is further provided with a plurality of reflux mechanisms, and each reflux mechanism comprises a reflux outlet pipe communicated with the upper end of the kettle body, a reflux inlet pipe communicated with the lower end of the kettle body, a reflux conveying pipe communicated with the reflux outlet pipe and the reflux inlet pipe, a reflux pump arranged on the reflux conveying pipe, a reflux valve arranged on the reflux conveying pipe, a flow guide pipe arranged in the kettle body and communicated with the reflux inlet pipe and a heat insulation shell arranged on the outer wall of the kettle body;
the reflux outlet pipe, the reflux conveying pipe, the reflux pump and the reflux inlet pipe are all positioned in the heat-insulating shell;
the guide pipe is provided with a plurality of guide holes, and the return outlet pipe is provided with a filter screen.
The invention also provides continuous supercritical extraction equipment which comprises an extractant tank, an extractant heat exchanger, a material heat exchanger, a separator and the extraction reaction kettle;
the extractant tank is communicated with the extractant heat exchanger through a first conveying pipeline, and an extractant conveying pump is arranged on the extractant conveying pipeline;
the extractant heat exchanger is communicated with an extractant inlet pipe of the extraction reaction kettle through a second conveying pipeline;
the extractant outlet pipe of the extraction reaction kettle is communicated with the separator through a third conveying pipeline, and the separator is communicated with the extractant tank through a fourth conveying pipeline;
the material heat exchanger is used for heating the material to a required temperature and then providing the material to the extraction reaction kettle, and the extractant heat exchanger is used for adjusting the extractant in the extractant tank to the required temperature and then providing the extractant to the extraction reaction kettle.
The invention also provides a method for continuous supercritical extraction by adopting the equipment, which comprises the following steps:
s1, filling materials heated to a required temperature through the material heat exchanger into the extraction reaction kettle through the feeding pipe, wherein the height of the materials is lower than that of the reflux outlet pipe;
s2, conveying the extractant in the extractant tank to an extractant heat exchanger through an extractant conveying pump, and conveying the extractant into the extraction reaction kettle after the extractant reaches the required temperature;
s3, in the first extraction stage, the reflux valve is closed, the reflux pump does not work, the extractant flowing to the upper part in the extraction reaction kettle is discharged from the extractant outlet pipe and then enters the separator, the separated extractant is discharged out of the separator, and the separated extractant is conveyed to the extractant tank for recycling;
s4, in a second extraction stage, the reflux valve is opened, the reflux pump works, a part of extractant flowing to the upper part in the extraction reaction kettle flows back to the lower end in the extraction reaction kettle after passing through the reflux outlet pipe, the reflux conveying pipe, the reflux inlet pipe and the guide pipe, the other part of extractant is discharged from the extractant outlet pipe and enters the separator, the separated extract is discharged out of the separator, and the separated extractant is conveyed into the extractant tank for recycling;
in the second extraction stage, the materials heated to the required temperature by the material heat exchanger are fed into the extraction reaction kettle through the feeding mechanism, and the slag at the bottom of the extraction reaction kettle is discharged through the continuous slag discharging mechanism.
The beneficial effects of the invention are as follows:
according to the continuous supercritical extraction reaction kettle provided by the invention, the continuous slag discharging mechanism and the feeding mechanism are arranged, so that feeding and discharging operations without stopping can be realized, and continuous supercritical extraction operation is realized;
in the continuous slag discharging mechanism, the slag discharging operation can be realized under the condition of not influencing the pressure in the kettle body through ingenious matching of the slag discharging inner box and the slag discharging outer box, and only one set of power device is needed for carrying out one-time extension and shortening operation by the power device when the slag discharging is carried out once; in the feeding mechanism, continuous feeding operation under the condition of not influencing the pressure in the kettle body can be realized through ingenious matching of the feeding inner box and the feeding outer box by one mechanism, and only one set of power device is needed for one-time extension and shortening operation by the power device when one-time slag discharging is carried out; in the feeding and slag discharging operation, the smooth falling of materials/slag can be promoted by the driving force of the power device through the vibration action provided by the elastic sheet and the gravity action, and the invention simplifies equipment and operation and can be beneficial to improving the efficiency;
according to the invention, by arranging the reflux mechanism, part of the extractant is refluxed to the bottom of the kettle body in the later extraction period to re-extract the materials, so that the content of a target object in the extractant discharged from the upper part of the kettle body can be increased, and the consumption of the extractant is reduced; on the other hand, because the extractant flowing back into the kettle body horizontally enters and has a certain flow velocity, the extractant which flows horizontally can be formed in the kettle body, and the extractant which flows upwards and enters from the bottom is compounded with the extractant which flows upwards, so that a cyclone effect can be generated, the contact collision between the extractant and materials is promoted, and the extraction efficiency and the recovery rate of the extract can be effectively improved;
in some embodiments of the invention, the ultrasonic transducer is arranged to generate oscillation effect in the kettle body, which is beneficial to improving extraction efficiency.
Detailed Description
The present invention is described in further detail below with reference to examples to enable those skilled in the art to practice the same by referring to the description.
It will be understood that terms, such as "having," "including," and "comprising," as used herein, do not preclude the presence or addition of one or more other elements or groups thereof.
Example 1
Referring to fig. 1 to 8, a continuous supercritical extraction reaction kettle of the present embodiment includes a kettle body 1, a feed pipe 2 disposed at the top of the kettle body 1, and a slag outlet 3 disposed at the bottom of the kettle body 1, wherein the top and bottom of the kettle body 1 are further provided with a feeding mechanism 4 and a continuous slag outlet mechanism 5, respectively;
the continuous slag discharging mechanism 5 comprises a slag discharging outer box 50 connected to the slag discharging opening 3, a sub slag inlet 500 arranged at the top of the slag discharging outer box 50 and communicated with the slag discharging opening 3, a sub slag discharging opening 501 arranged at the bottom of the slag discharging outer box 50, a slag discharging inner box 51 which can be arranged in the slag discharging outer box 50 in a sliding manner along the horizontal direction, a slag discharging sealing plate 52 connected to the outer side of the slag discharging inner box 51 and a slag discharging driving mechanism 53 for driving the slag discharging inner box 51 to slide horizontally in a reciprocating manner so as to switch back and forth between a slag feeding state and a slag discharging state, wherein the top and the bottom of the slag discharging inner box 51 are opened to form an upper slag feeding opening 510 and a lower slag discharging opening 511 respectively;
in the slag-in state, the upper slag-in opening 510 of the slag inner box 51 communicates with the sub slag-in opening 500 and the lower slag-out opening 511 is sealed by the bottom surface of the slag outer box 50;
in the slag discharge state, the lower slag discharge opening 511 of the slag inner box 51 communicates with the sub slag discharge hole 501 and the slag sealing plate 52 seals the sub slag inlet 500.
According to the invention, by arranging the continuous slag discharging mechanism 5, the machine is not required to be stopped when slag is discharged, and when the continuous slag discharging mechanism 5 is used for discharging slag in the kettle body 1, the kettle body 1 can still normally perform extraction operation, and the pressure in the kettle body 1 is basically unchanged; by arranging the feeding mechanism 4, the machine does not need to be stopped during feeding, and when new materials are filled into the kettle body 1 by using the feeding mechanism 4, the kettle body 1 can still normally perform extraction operation, and the pressure inside the kettle body 1 is basically unchanged; thereby realizing continuous supercritical extraction operation of the reaction kettle.
In a preferred embodiment, the extractant is carbon dioxide.
In a preferred embodiment, the bottom of the kettle body 1 is provided with an extractant inlet tube 10, and the top of the kettle body 1 is provided with an extractant outlet tube 11.
In a preferred embodiment, a seal is provided on the sub slag notch 500 or on the upper surface of the slag sealing plate 52 to ensure that the slag sealing plate 52 maintains a good seal when it covers the sub slag notch 500. The bottom plate of the slag discharging outer box 50 under the lower slag discharging opening 511 or under the lower slag discharging opening 511 is also provided with a sealing member to ensure that the bottom plate of the slag discharging outer box 50 can form a good sealing effect on the slag discharging opening when the slag discharging opening is contacted with the bottom plate of the slag discharging outer box 50.
In a preferred embodiment, the tapping drive mechanism 53 is an electric push rod provided in the tapping outer box 50 at the side of the tapping inner box 51, and pushes the tapping inner box 51 to reciprocate left and right by the extension and shortening of the electric push rod.
In the preferred embodiment, the slag discharging elastic sheet 512 is also arranged on the outer wall of the slag discharging inner box 51 at the side opposite to the electric push rod; when the electric push rod pushes the slag discharging inner box 51 to move to the rightmost end, the slag discharging elastic sheet 512 is in contact with the inner wall of the slag discharging outer box 50, so that on one hand, buffering is performed, and on the other hand, the smooth falling of the slag in the slag discharging inner box 51 can be promoted through the vibration effect brought by impact.
In the preferred embodiment, a sub slag discharging pipe 54 is also connected to the sub slag discharging port 501; the continuous slag discharging mechanism 5 further comprises a protective shell 55, the slag discharging outer box 50 is arranged in the protective shell 55, a slag discharging outlet 56 is formed in the bottom of the protective shell 55, and an outlet cover plate 57 is arranged on the slag discharging outlet 56. The protective casing 55 is used for protecting the continuous slag discharging mechanism, and when slag is discharged, the outlet cover plate 57 is opened, and the slag is discharged through the slag discharging outlet 56 after being discharged through the sub slag discharging pipe 54.
Referring to fig. 3-5, the continuous tapping mechanism 5 operates on the principle of:
1. when supercritical extraction operation is carried out in the kettle body 1, the extracted slag at the bottom of the kettle body 1 enters the slag inner box 51 through the slag outlet 3, the sub slag inlet 500 and the upper slag inlet opening 510 of the slag outer box 50 under the action of gravity, and at the moment, the bottom plate of the slag outer box 50 seals the lower slag outlet opening 511 of the slag inner box 51, so that the slag outlet 3 is kept sealed, and the pressure in the kettle body 1 can be kept in a set state, as shown in fig. 3;
2. when deslagging is carried out, the electric push rod stretches rightward to push the deslagging inner box 51 to move to the rightmost end, and at the moment, the slag sealing plate completely covers the slag inlet 500 from below and can keep good sealing, so that slag in the kettle body 1 is prevented from continuously falling and isolated from the outside, and the kettle body 1 is prevented from being polluted; meanwhile, the lower slag outlet opening 511 of the slag discharging inner box 51 reaches the position right above the sub slag discharging hole 501 and is communicated with each other, and slag in the slag discharging inner box 51 rapidly falls under the action of gravity and the vibration caused by collision between the slag discharging elastic sheet 512 on the slag discharging inner box 51 and the inner wall of the slag discharging outer box 50, and is discharged from the sub slag discharging hole 501 as shown in fig. 5;
the steps 1 and 2 are repeated, so that the slag in the kettle body 1 can be continuously discharged under the condition of no shutdown.
In the preferred embodiment, the feeding mechanism 4 comprises a feeding pipe 40 arranged at the top of the kettle body 1 in a communicating manner, a feeding outer box 41 connected to the feeding pipe 40, a feeding inlet 410 arranged at the top of the feeding outer box 41, a feeding outlet 411 arranged at the bottom of the feeding outer box 41 and communicated with the feeding pipe 40, a feeding inner box 42 slidably arranged in the feeding outer box 41 in the horizontal direction, an upper feeding sealing plate 43 and a lower feeding sealing plate 44 connected to the outer side of the feeding inner box 42, and a feeding driving mechanism 45 for driving the feeding inner box 42 to slide reciprocally and horizontally to switch back and forth between a feeding state and a discharging state, wherein the top and the bottom of the feeding inner box 42 are opened to form an upper feeding opening 420 and a lower discharging opening 421 respectively.
In the fed state, the upper feed opening 420 of the fed inner case 42 is communicated with the fed inlet 410 and the lower discharge opening 421 is sealed by the bottom surface of the fed outer case 41, while the lower fed sealing plate 44 seals the fed pipe 40;
in the discharged state, the lower discharge opening 421 of the feed inner box 42 communicates with the feed outlet 411 and the upper feed sealing plate 43 seals the feed inlet 410.
In a preferred embodiment, the feeding driving mechanism 45 is an electric push rod, and the feeding inner case 42 is pushed to reciprocate left and right by the extension and shortening of the electric push rod.
In a preferred embodiment, a feed spring 422 is also provided on the outer wall of the lower feed seal plate 44 on the side opposite the feed drive mechanism 45. When the electric push rod pushes the feeding inner box 42 to move to the rightmost end, the feeding elastic sheet 422 is in contact with the inner wall of the feeding outer box 41, so that on one hand, buffering is performed, and on the other hand, the smooth falling of materials in the feeding inner box 42 can be promoted through the vibration effect brought by impact.
In the preferred embodiment, the feed inlet 410 is provided with a feed reservoir 46 in the form of a horn communicating therewith, and the feed reservoir 46 is provided with a feed cover 47 at its top opening.
In a preferred embodiment, the upper surface of the upper feed inlet 410 or the upper feed sealing plate 43 is provided with a sealing member to ensure that the upper feed sealing plate 43 covers the upper feed inlet 410 and maintains a good sealing effect. The upper surface of the feed outlet 411 or the lower feed sealing plate 44 is also provided with a sealing member to ensure that the lower feed sealing plate 44 can maintain a good sealing effect when covering the feed outlet 411.
Referring to fig. 6-8, the feed mechanism 4 operates on the following principle:
1. when new materials are fed into the kettle body 1, the feeding cover plate 47 is opened first, the new materials are provided into the feeding container 46, the materials fall into the feeding inner box 42, and at the moment, the feeding pipe 40 is kept in a sealed state because the lower feeding sealing plate 44 is covered on the feeding outlet 411 in a sealing way, as shown in fig. 6;
2. then the electric push rod works to push the feeding inner box 42 to move to the rightmost end, the feeding elastic sheet 422 is in contact with the inner wall of the feeding outer box 41, as shown in fig. 7, at the moment, the upper feeding sealing plate 43 completely covers and seals the feeding inlet 410, the lower feeding sealing plate 44 is completely separated from the feeding outlet 411, the lower discharging opening 421 of the feeding inner box 42 reaches the upper end of the feeding pipe 40 and is mutually communicated, and under the action of gravity and the vibration caused by collision between the feeding elastic sheet 422 on the lower feeding sealing plate 44 and the inner wall of the feeding outer box 41, the slag in the feeding inner box 42 rapidly falls down, and enters the kettle body 1 through the feeding pipe 40, so as to realize feeding, as shown in fig. 8;
and repeating the steps 1 and 2, so that new materials can be continuously filled into the kettle body 1 under the condition of no shutdown.
In the preferred embodiment, the kettle body 1 is further provided with a stirring mechanism 6, and the stirring mechanism 6 comprises a frame 60 arranged on the kettle body 1, a stirring motor 61 arranged on the frame 60, a stirring shaft 62 in driving connection with an output shaft of the stirring motor 61 and extending into the kettle body 1, and a plurality of stirring blades 63 arranged on the stirring shaft 62 at intervals along the vertical direction, wherein the stirring mechanism can promote the contact of the extractant and the materials through stirring, so that the extraction efficiency is improved.
In a further preferred embodiment, the kettle body 1 is further provided with an ultrasonic transducer 64, and an ultrasonic field provided by the ultrasonic transducer 64 can generate an oscillation effect, so that the inter-phase mass transfer speed is accelerated, extraction is facilitated, and the extraction efficiency is further improved.
In one embodiment, a plurality of ultrasonic transducers 64 are provided on the inner wall of the tank 1. In another embodiment, the ultrasonic transducer 64 is arranged on the stirring blade 63 or the stirring shaft 62, so that the ultrasonic transducer 64 is driven to rotate by the stirring shaft 62, and the ultrasonic field can be more fully and uniformly applied to the extraction system in the kettle body 1. For example, in this embodiment, the ultrasonic transducer 64 is disposed on the surface of the stirring blade 63 (at this time, a protective layer is required to be disposed outside the ultrasonic transducer 64 to isolate the extraction system in the kettle body 1 from the ultrasonic transducer 64) or inside the stirring shaft 62, and a mounting wire is disposed inside the stirring shaft 62 to supply electric energy to the ultrasonic transducer 64 through the wire, and the wire does not affect the rotation of the stirring shaft 62.
Example 2
Referring to fig. 1 and 9, in this embodiment, as a further improvement on the basis of embodiment 1, a plurality of reflux mechanisms 7 are further provided on the kettle body 1, wherein the reflux mechanisms 7 include a reflux outlet pipe 70 communicated with the upper end of the kettle body 1, a reflux inlet pipe 71 communicated with the lower end of the kettle body 1, a reflux delivery pipe 72 communicated with the reflux outlet pipe 70 and the reflux inlet pipe 71, a reflux pump 73 provided on the reflux delivery pipe 72, a reflux valve 74 provided on the reflux delivery pipe 72, a draft tube 75 provided inside the kettle body 1 and communicated with the reflux inlet pipe 71, and a heat-insulating casing 76 provided on the outer wall of the kettle body 1;
the heat-insulating shell 76 is used for reducing heat exchange between the reflux mechanism 7 and the outside, and ensuring that the temperature of the extractant in the reflux mechanism 7 is basically consistent with that in the kettle body 1.
The return outlet pipe 70, the return delivery pipe 72, the return pump 73 and the return inlet pipe 71 are all inside the insulating housing 76;
the flow guide pipe 75 is provided with a plurality of flow guide holes 77, and the return outlet pipe 70 is provided with a filter screen 78.
In the earlier stage of extraction, the content of a target object (required extract) in the material is high, the extraction efficiency is high, the content of the target object in the extracting agent discharged from the upper part of the kettle body 1 is also high, and at the moment, the reflux mechanism 7 can not work; along with the extraction, the content of the target in the material is reduced, and the content of the target in the extractant discharged from the upper part of the kettle body 1 is also reduced, at the moment, part of the extractant is refluxed to the bottom through a reflux mechanism 7 to re-extract the material, so that the content of the target in the extractant discharged from the upper part of the kettle body 1 can be improved, and the consumption of the extractant is reduced; on the other hand, because the extractant flowing back into the kettle body 1 horizontally enters and has a certain flow velocity, the extractant which flows horizontally can be formed in the kettle body 1, and the extractant which flows upwards and enters from the bottom can be compounded with the extractant which flows upwards, so that a cyclone effect can be generated, the contact collision between the extractant and materials is promoted, and the extraction efficiency and the recovery rate of the extract can be effectively improved.
Example 3
Referring to fig. 10, as a further improvement on the basis of embodiment 2, the present embodiment also provides a continuous supercritical extraction apparatus, which includes an extractant tank 101, an extractant heat exchanger 102, a material heat exchanger 103, a separator 104, and an extraction reaction kettle as above;
the extractant tank 101 is communicated with the extractant heat exchanger 102 through a first conveying pipeline 105, and an extractant conveying pump 106 is arranged on the extractant conveying pipeline;
the extractant heat exchanger 102 is communicated with the extractant inlet pipe 10 of the extraction reaction kettle through a second conveying pipeline 107;
the extractant outlet pipe 11 of the extraction reaction kettle is communicated with the separator 104 through a third conveying pipeline 108, and the separator 104 is communicated with the extractant tank 101 through a fourth conveying pipeline 109;
the material heat exchanger 103 is used for heating the material to a required temperature and then providing the material to the extraction reaction kettle, and the extractant heat exchanger 102 is used for adjusting the extractant in the extractant tank 101 to the required temperature and then providing the extractant to the extraction reaction kettle.
The extractant in this example is carbon dioxide
The invention also provides a method for continuous supercritical extraction by adopting the equipment, which comprises the following steps:
s1, filling a material heated to a required temperature through a material heat exchanger 103 into an extraction reaction kettle through a feed pipe 2, wherein the height of the material is lower than that of a reflux outlet pipe 70;
s2, conveying the extractant in the extractant tank 101 to the extractant heat exchanger 102 through the extractant conveying pump 106, and conveying the extractant into the extraction reaction kettle after the extractant reaches the required temperature;
s3, in the first extraction stage, a reflux valve 74 is closed, a reflux pump 73 does not work, the extractant flowing to the upper part in the extraction reaction kettle is discharged from an extractant outlet pipe 11 and then enters a separator 104, the separated extractant is discharged from the separator 104, and the separated extractant is conveyed to an extractant tank 101 for recycling;
s4, in the second extraction stage, a reflux valve 74 is opened, a reflux pump 73 works, a part of extractant flowing to the upper part in the extraction reaction kettle flows back to the lower end in the extraction reaction kettle through a reflux outlet pipe 70, a reflux conveying pipe 72, a reflux inlet pipe 71 and a guide pipe 75, the other part of extractant is discharged from an extractant outlet pipe 11 and then enters a separator 104, the separated extract is discharged from the separator 104, and the separated extractant is conveyed to an extractant tank 101 for recycling;
wherein, in the second extraction stage, the materials heated to the required temperature by the material heat exchanger 103 are fed into the extraction reaction kettle through the feeding mechanism 4 (for example, the material heat exchanger 103 is directly connected with the feeding container 46 through a pipeline so as to send the materials heated by the material heat exchanger 103 into the feeding mechanism 4), and the slag at the bottom of the extraction reaction kettle is discharged through the continuous slag discharging mechanism 5.
Although embodiments of the present invention have been disclosed above, it is not limited to the use of the description and embodiments, it is well suited to various fields of use for the invention, and further modifications may be readily apparent to those skilled in the art, and accordingly, the invention is not limited to the particular details without departing from the general concepts defined in the claims and the equivalents thereof.