Method for controlling feeding amount and composition of extracting agent of extraction tower

Abstract

The invention relates to a method for controlling the feeding amount and composition of an extraction agent of an extraction tower, which is based on the proportional relation between the total feeding amount of the extraction agent and the feeding amount of a reaction liquid and the concentration of a first component and a second component of the extraction agent in the extraction agent. Further constructing a relational expression of the total feeding amount of the recycled extraction agent, the first extraction agent component and the second extraction agent component and the feeding amount of the reaction liquid and a relational expression for ensuring that the composition of the extraction agent meets the requirement, and meanwhile, limiting the upper limit value of the flow of the recycled extraction agent; the feeding amount of the recycled extracting agent, the feeding amount of the first component of the extracting agent and the feeding amount of the second component of the extracting agent are respectively used as corresponding feeding amount set values, so that when the feeding amount of the reaction liquid fluctuates or is adjusted in any range, the total feeding amount of the extracting agent entering the extraction tower is ensured to change in the same proportion and the composition is not changed; the extraction effect of the extraction tower is ensured.

Description

Technical Field

[0001] The invention relates to the technical field of extraction, and in particular to a method for controlling the feed amount and composition of an extractant of an extraction tower. Background Art

[0002] Extraction, also known as solvent extraction or liquid-liquid extraction, also known as extraction, is a method of transferring solute from one solvent to another by utilizing the difference in solubility or distribution coefficient of a substance in two immiscible or slightly soluble solvents. It is widely used in chemical, metallurgical, food and other industries.

[0003] At present, in some extraction processes, the extractant is not composed of a single material, but is composed of two or even more materials. During the operation of the device, the composition of the extractant has a great influence on the extraction effect. The composition of the extractant materials needs to be fixed at a certain ratio to ensure both the extraction yield and a good impurity removal effect; at the same time, the feed amount of the extractant must also maintain a certain ratio with the feed amount of the extracted material, otherwise it will lead to incomplete extraction or emulsification.

[0004] CN 219502021U discloses an energy-saving automatic control mechanism for an extraction device, comprising an extractor and an extractant liquid inlet pipe and a raw material liquid inlet pipe installed outside the extractor, wherein the extractant liquid inlet pipe and the raw material liquid inlet pipe are respectively provided with an extractant liquid pump and a raw material liquid pump outside, and an extractant flowmeter is provided outside the extractant liquid inlet pipe. The utility model detects the liquid flow in the extractant liquid inlet pipe and the flowmeter liquid inlet pipe in real time through the extractant flowmeter and the raw material flowmeter, and controls the frequency converter according to the information transmitted by the extractant flowmeter and the raw material flowmeter through the PID controller, so that the actual working current of the extractant liquid pump can be adjusted according to the real-time working state, avoiding the situation that the extractant liquid pump continuously works efficiently and causes unnecessary energy waste, but cannot realize the online real-time control of the extractant composition.

[0005] CN 209317094U discloses a quantitative dosing device for laboratory extractant, comprising a base, a telescopic sleeve rod installed on the top of the base, a telescopic rod installed on the top of the telescopic sleeve rod, a liquid level sensor installed inside the feeding hopper, a feeding pipe installed at the bottom of the feeding hopper, an inner cavity installed at the top of the inner cavity, an inductor coil installed at the top of the inner cavity, a permanent magnet arranged at the bottom of the inner cavity, a discharge port arranged at the bottom of the inner cavity, through holes arranged on both sides of the bottom of the inner cavity, a liquid flow meter installed on the feeding pipe, a protective shell installed on the top of the base, and a warning light and a PLC controller installed on the surface of the protective shell. The utility model solves the problem that the existing equipment does not have quantitative dosing and has a single function by arranging a liquid flow meter, a PLC controller, an inductor coil, a telescopic rod, a liquid level sensor and a warning light structure, but when the reaction liquid feed amount fluctuates or is adjusted in any range, it cannot ensure that the total amount of feed of the extractant entering the extraction tower changes in the same proportion and the composition remains unchanged.

[0006] Therefore, in view of the shortcomings of the prior art, it is urgently necessary to provide a control method that ensures that the total amount of extractant entering the extraction tower changes in proportion and the composition remains unchanged when the feed amount of the extracted material fluctuates or is adjusted within any range. Summary of the invention

[0007] The object of the present invention is to provide a method for controlling the feed amount and composition of an extractant of an extraction tower, which can ensure that the total feed amount of the extractant entering the extraction tower changes in the same proportion and the composition remains unchanged when the feed amount of the reaction solution fluctuates or is adjusted in any range, thereby ensuring the extraction effect of the extraction tower.

[0008] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0009] The present invention provides a method for controlling the feed amount and composition of an extractant of an extraction tower, the control method comprising the following steps:

[0010] The feed of the extraction tower includes the reaction solution to be extracted and the extractant; the feed of the extractant includes the recycled extractant, the first component of the extractant and the second component of the extractant;

[0011] The relationship between the total amount of the recycled extractant, the first component of the extractant and the second component of the extractant and the amount of the reaction solution fed is as shown in formula (1):

[0012] FT 02 +FT 03 +FT 04 = k × FT 01 ; (1)

[0013] Among them: FT 02 Indicates the feed amount of recycled extractant, FT 02 ≥0; FT03 Indicates the feed amount of the first component of the extractant, FT 03 ≥0; FT 04 Indicates the feed amount of the second component of the extractant, FT 04 ≥0; FT 01 represents the feed amount of the reaction liquid; k represents the ratio coefficient of the total feed amount of the extractant to the feed amount of the reaction liquid, and k is 0.1-10;

[0014] The relationship between the recycled extractant, the first extractant component and the second extractant component is shown in formula (2) and formula (3):

[0015]

[0016] Where: C R4 Indicates the concentration of the first component of the extractant in the recycled extractant; C A represents the concentration of the first component of the extractant in the extractant; C RB Indicates the concentration of the second component of the extractant in the recycled extractant; C B represents the concentration of the second component of the extractant in the extractant;

[0017] The flow rate of the recycled extractant satisfies formula (4):

[0018] FT 02 ≤FT 02 UP LIMIT ; (4)

[0019] Among them: FT 02 UP LIMIT Indicates the upper limit of the flow rate of the recycled extractant;

[0020] Then, according to formula (1)-formula (4), the feed amount of recycled extractant FT is calculated 02 , the feed amount of the first component of the extractant FT 03 and the feed amount FT of the second component of the extractant 04 , and are used as feed amount set values ​​for the recycled extractant, the first component of the extractant, and the second component of the extractant, respectively, and are adjusted through the control loop.

[0021] The method for controlling the feed amount and composition of the extractant of the extraction tower provided by the present invention is based on the proportional relationship between the total feed amount of the extractant and the feed amount of the reaction liquid, and the concentrations of the first component of the extractant and the second component of the extractant in the extractant, and then constructs a relationship between the total feed amount of the recycled extractant, the first component of the extractant, the second component of the extractant and the feed amount of the reaction liquid, and a relationship to ensure that the composition of the extractant meets the requirements, and at the same time limits the upper limit of the flow rate of the recycled extractant, so as to calculate the recycled extractant feed amount FT 02 , the feed amount of the first component of the extractant FT 03and the feed amount FT of the second component of the extractant 04 , and are used as the feed amount setting values ​​of the recycled extractant, the first component of the extractant and the second component of the extractant respectively, so that when the feed amount of the reaction liquid fluctuates or is adjusted in any range, the total feed amount of the extractant entering the extraction tower can be guaranteed to change in the same proportion and the composition remains unchanged, thereby ensuring the extraction effect of the extraction tower.

[0022] The ratio coefficient k of the total amount of the extractant feed to the reaction solution feed is 0.1-10, for example, 0.1, 1.1, 3, 5, 8 or 10, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0023] Preferably, the calculation of the recycled extractant feed amount FT 02 To satisfy the conditions of equations (1) to (4), calculate the maximum value of the feed amount of the recycled extractant, max FT: 02 .

[0024] In order to maximize the use of recycled extractant and reduce the use of fresh extractant first component and second component, the amount of recycled extractant FT should be optimized according to formula (1)-formula (4): 02 , under the condition of satisfying the above mathematical constraints, using a computer solution program, we can obtain FT 02 The maximum value of .

[0025] Preferably, the feed pipeline of the extraction tower includes a reaction liquid feed pipeline and an extractant feed pipeline, and the extractant feed pipeline includes a recycled extractant feed pipeline, an extractant first component feed pipeline and an extractant second component feed pipeline arranged in parallel.

[0026] Preferably, the reaction liquid feeding pipeline is provided with a first flow meter, a first flow controller and a first flow regulating valve.

[0027] Preferably, the recycled extractant feed pipeline is provided with a second flow meter, a second flow controller and a second flow regulating valve.

[0028] Preferably, the recycled extractant feed pipeline is also provided with an extractant composition online analyzer for online measuring the concentration C of the first component of the extractant in the recycled extractant. RA The concentration of the second component of the extractant in the recycled extractant C RB .

[0029] Preferably, the extractant first component feed pipeline is provided with a third flow meter, a third flow controller and a third flow regulating valve.

[0030] Preferably, the extractant second component feed pipeline is provided with a fourth flow meter, a fourth flow controller and a fourth flow regulating valve.

[0031] Preferably, the discharge pipeline of the extraction tower comprises an extraction phase discharge pipeline connected to the top of the extraction tower and a raffinate phase discharge pipeline connected to the bottom of the extraction tower.

[0032] As a preferred technical solution of the control method described in the present invention, the control method comprises the following steps:

[0033] The feed of the extraction tower includes the reaction solution to be extracted and the extractant; the feed of the extractant includes the recycled extractant, the first component of the extractant and the second component of the extractant;

[0034] The relationship between the total amount of the recycled extractant, the first component of the extractant and the second component of the extractant and the amount of the reaction solution fed is as shown in formula (1):

[0035] FT 02 +FT 03 +FT 04 = k × FT 01 ; (1)

[0036] Among them: FT 02 Indicates the feed amount of recycled extractant, FT 02 ≥0; FT 03 Indicates the feed amount of the first component of the extractant, FT 03 ≥0; FT 04 Indicates the feed amount of the second component of the extractant, FT 04 ≥0; FT 01 represents the feed amount of the reaction liquid; k represents the ratio coefficient of the total feed amount of the extractant to the feed amount of the reaction liquid, and k is 0.1-10;

[0037] The relationship between the recycled extractant, the first extractant component and the second extractant component is shown in formula (2) and formula (3):

[0038]

[0039] Where: C RA Indicates the concentration of the first component of the extractant in the recycled extractant; C A represents the concentration of the first component of the extractant in the extractant; C RB Indicates the concentration of the second component of the extractant in the recycled extractant; C B represents the concentration of the second component of the extractant in the extractant;

[0040] The flow rate of the recycled extractant satisfies formula (4):

[0041] FT 02 ≤FT 02 UP LIMIT ; (4)

[0042] Among them: FT02 UP LIMIT Indicates the upper limit of the flow rate of the recycled extractant;

[0043] Then, according to formula (1)-formula (4), the maximum value of the recycled extractant feed amount max FT is calculated 02 , the feed amount of the first component of the extractant FT 03 and the feed amount FT of the second component of the extractant 04 , and are used as feed amount setting values ​​of the recycled extractant, the first component of the extractant, and the second component of the extractant, respectively, and are adjusted through the control loop;

[0044] The feed pipeline of the extraction tower includes a reaction liquid feed pipeline and an extractant feed pipeline, and the extractant feed pipeline includes a recycled extractant feed pipeline, a first component extractant feed pipeline and a second component extractant feed pipeline arranged in parallel;

[0045] The reaction liquid feed pipeline is provided with a first flow meter, a first flow controller and a first flow regulating valve; the recycled extractant feed pipeline is provided with a second flow meter, a second flow controller, a second flow regulating valve and an extractant composition online analyzer, and the extractant composition online analyzer is used to online measure the concentration C of the first component of the extractant in the recycled extractant. RA The concentration of the second component of the extractant in the recycled extractant C RB The first component of the extractant feed pipeline is provided with a third flow meter, a third flow controller and a third flow regulating valve; the second component of the extractant feed pipeline is provided with a fourth flow meter, a fourth flow controller and a fourth flow regulating valve;

[0046] The discharge pipeline of the extraction tower comprises an extraction phase discharge pipeline connected to the top of the extraction tower and a raffinate phase discharge pipeline connected to the bottom of the extraction tower.

[0047] Compared with the prior art, the present invention has the following beneficial effects:

[0048] The method for controlling the feed amount and composition of the extractant of the extraction tower provided by the present invention is based on the proportional relationship between the total feed amount of the extractant and the feed amount of the reaction liquid, and the concentrations of the first component of the extractant and the second component of the extractant in the extractant, and then constructs a relationship between the total feed amount of the recycled extractant, the first component of the extractant, the second component of the extractant and the feed amount of the reaction liquid, and a relationship to ensure that the composition of the extractant meets the requirements, and at the same time limits the upper limit of the flow rate of the recycled extractant, so as to calculate the recycled extractant feed amount FT 02 , the feed amount of the first component of the extractant FT 03 and the feed amount FT of the second component of the extractant 04, and are used as the feed amount setting values ​​of the recycled extractant, the first component of the extractant and the second component of the extractant respectively, so that when the feed amount of the reaction liquid fluctuates or is adjusted in any range, the total feed amount of the extractant entering the extraction tower can be guaranteed to change in the same proportion and the composition remains unchanged, thereby ensuring the extraction effect of the extraction tower. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 It is a schematic structural diagram of a feed pipeline and a discharge pipeline of an extraction tower provided in Example 1 of the present invention;

[0050] Among them: 1, reaction liquid feed pipeline; 2, recycled extractant feed pipeline; 3, extractant first component feed pipeline; 4, extractant second component feed pipeline; 5, extract phase discharge pipeline; 6, raffinate phase discharge pipeline;

[0051] 11, first flow meter; 12, first flow controller; 13, first flow regulating valve; 21, second flow meter; 22, second flow controller; 23, second flow regulating valve; 24, online analyzer for extractant composition; 31, third flow meter; 32, third flow controller; 33, third flow regulating valve; 41, fourth flow meter; 42, fourth flow controller; 43, fourth flow regulating valve. DETAILED DESCRIPTION

[0052] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0053] The present invention provides a method for controlling the feed amount and composition of an extractant of an extraction tower, the control method comprising the following steps:

[0054] The feed of the extraction tower includes the reaction solution to be extracted and the extractant; the feed of the extractant includes the recycled extractant, the first component of the extractant and the second component of the extractant;

[0055] First, according to the process requirements, determine the ratio coefficient k of the total amount of extractant feed to the reaction solution feed, the concentration C of the first component of the extractant in the extractant, and the A and the concentration C of the second component of the extractant in the extractant B Then, a relationship between the total amount of feed of the recycled extractant, the first component of the extractant and the second component of the extractant and the feed amount of the reaction solution is constructed, and a relationship between the recycled extractant, the first component of the extractant and the second component of the extractant is constructed, and at the same time, the upper limit of the flow rate of the recycled extractant is limited, so as to calculate the recycled extractant feed amount FT 02 , the feed amount of the first component of the extractant FT 03 and the feed amount FT of the second component of the extractant 04, and are used as the feed amount setting values ​​of the recycled extractant, the first component of the extractant, and the second component of the extractant, respectively. The specific process is as follows:

[0056] The relationship between the total amount of the recycled extractant, the first component of the extractant and the second component of the extractant and the amount of the reaction solution fed is as shown in formula (1):

[0057] FT 02 +FT 03 +FT 04 = k × FT 01 ; (1)

[0058] Among them: FT 02 Indicates the feed amount of recycled extractant, FT 02 ≥0; FT 03 Indicates the feed amount of the first component of the extractant, FT 03 ≥0; FT 04 Indicates the feed amount of the second component of the extractant, FT 04 ≥0; FT 01 represents the feed amount of the reaction liquid; k represents the ratio coefficient of the total feed amount of the extractant to the feed amount of the reaction liquid, and k is 0.1-10;

[0059] The relationship between the recycled extractant, the first extractant component and the second extractant component is shown in formula (2) and formula (3):

[0060]

[0061] Where: C RA Indicates the concentration of the first component of the extractant in the recycled extractant; C A represents the concentration of the first component of the extractant in the extractant; C RB Indicates the concentration of the second component of the extractant in the recycled extractant; C B represents the concentration of the second component of the extractant in the extractant;

[0062] The flow rate of the recycled extractant satisfies formula (4):

[0063] FT 02 ≤FT 02 UP LIMIT ; (4)

[0064] Among them: FT 02 UP LIMIT Indicates the upper limit of the flow rate of the recycled extractant;

[0065] Then, according to formula (1)-formula (4), the maximum value of the recycled extractant feed amount max FT is calculated 02 , the feed amount of the first component of the extractant FT 03 and the feed amount FT of the second component of the extractant 04, and are used as feed amount setting values ​​of the recycled extractant, the first component of the extractant, and the second component of the extractant, respectively, and are adjusted through the control loop;

[0066] The feed pipeline of the extraction tower includes a reaction liquid feed pipeline and an extractant feed pipeline, and the extractant feed pipeline includes a recycled extractant feed pipeline, a first component extractant feed pipeline and a second component extractant feed pipeline arranged in parallel;

[0067] The reaction liquid feed pipeline is provided with a first flow meter, a first flow controller and a first flow regulating valve; the recycled extractant feed pipeline is provided with a second flow meter, a second flow controller, a second flow regulating valve and an extractant composition online analyzer, and the extractant composition online analyzer is used to online measure the concentration C of the first component of the extractant in the recycled extractant. RA The concentration of the second component of the extractant in the recycled extractant C RB The first component of the extractant feed pipeline is provided with a third flow meter, a third flow controller and a third flow regulating valve; the second component of the extractant feed pipeline is provided with a fourth flow meter, a fourth flow controller and a fourth flow regulating valve;

[0068] The discharge pipeline of the extraction tower comprises an extraction phase discharge pipeline connected to the top of the extraction tower and a raffinate phase discharge pipeline connected to the bottom of the extraction tower.

[0069] Example 1

[0070] This embodiment provides a method for controlling the feed amount and composition of an extractant of an extraction tower, the control method comprising the following steps:

[0071] The feed of the extraction tower includes the reaction liquid to be extracted and the extractant; the reaction liquid is VA containing cyclohexane solvent, which contains a small amount of impurities to be extracted; the feed of the extractant includes the recycled extractant, the first component of the extractant, water, and the second component of the extractant, methanol;

[0072] The relationship between the total amount of the recycled extractant, the first component of the extractant and the second component of the extractant and the amount of the reaction solution fed is as shown in formula (1):

[0073] FT 02 +FT 03 +FT 04 = k × FT 01 ; (1)

[0074] Among them: FT 02 Indicates the feed amount of recycled extractant, FT 02 ≥0; FT 03 Indicates the feed amount of the first component of the extractant, FT 03 ≥0; FT04 Indicates the feed amount of the second component of the extractant, FT 04 ≥0; FT 01 represents the feed amount of the reaction liquid; k represents the ratio coefficient of the total feed amount of the extractant to the feed amount of the reaction liquid, and k is 1.1;

[0075] The relationship between the recycled extractant, the first extractant component and the second extractant component is shown in formula (2) and formula (3):

[0076]

[0077] Where: C RA Indicates the concentration of the first component of the extractant in the recycled extractant, C RA It is obtained by online real-time measurement; C A represents the concentration of the first component of the extractant in the extractant, C A 94%; C RB Indicates the concentration of the second component of the extractant in the recycled extractant, C RB It is obtained by online real-time measurement; C B represents the concentration of the second component of the extractant in the extractant, C B 6%;

[0078] The flow rate of the recycled extractant satisfies formula (4):

[0079] FT 02 ≤FT 02 UP LIMIT ; (4)

[0080] Among them: FT 02 UP LIMIT Indicates the upper limit of the flow rate of the recycled extractant, FT 02 UP LIMIT 2000kg / h;

[0081] Then, according to formula (1)-formula (4), the maximum value of the recycled extractant feed amount max FT is calculated 02 , the feed amount of the first component of the extractant FT 03 and the feed amount FT of the second component of the extractant 04 , and are used as feed amount setting values ​​of the recycled extractant, the first component of the extractant, and the second component of the extractant, respectively, and are adjusted through the control loop;

[0082] The structural schematic diagram of the feed pipeline and the discharge pipeline of the extraction tower is as follows: Figure 1 As shown, the feed pipeline of the extraction tower includes a reaction liquid feed pipeline 1 and an extractant feed pipeline, and the extractant feed pipeline includes a recycled extractant feed pipeline 2, an extractant first component feed pipeline 3 and an extractant second component feed pipeline 4 which are arranged in parallel;

[0083] The reaction liquid feed pipeline 1 is provided with a first flow meter 11, a first flow controller 12 and a first flow regulating valve 13; the recycled extractant feed pipeline 2 is provided with a second flow meter 21, a second flow controller 22, a second flow regulating valve 23 and an extractant composition online analyzer 24, and the extractant composition online analyzer 24 is used to measure the concentration C of the first component of the extractant in the recycled extractant online. RA The concentration of the second component of the extractant in the recycled extractant C RB The extractant first component feed pipeline 3 is provided with a third flow meter 31, a third flow controller 32 and a third flow regulating valve 33; the extractant second component feed pipeline 4 is provided with a fourth flow meter 41, a fourth flow controller 42 and a fourth flow regulating valve 43;

[0084] The discharge pipeline of the extraction tower includes an extraction phase discharge pipeline 5 connected to the top of the extraction tower and a raffinate phase discharge pipeline 6 connected to the bottom of the extraction tower.

[0085] This embodiment can achieve better control of the flow rate and composition of the extractant during normal production, greatly improving production efficiency and product quality stability.

[0086] In summary, the method for controlling the feed amount and composition of the extractant of the extraction tower provided by the present invention is based on the proportional relationship between the total feed amount of the extractant and the feed amount of the reaction liquid, and the concentrations of the first component of the extractant and the second component of the extractant in the extractant, and then constructs a relationship between the total feed amount of the recycled extractant, the first component of the extractant, the second component of the extractant, and the feed amount of the reaction liquid, as well as a relationship to ensure that the composition of the extractant meets the requirements, and at the same time limits the upper limit of the flow rate of the recycled extractant, so as to calculate the recycled extractant feed amount FT 02 , the feed amount of the first component of the extractant FT 03 and the feed amount FT of the second component of the extractant 04 , and are used as the feed amount setting values ​​of the recycled extractant, the first component of the extractant and the second component of the extractant respectively, so that when the feed amount of the reaction liquid fluctuates or is adjusted in any range, the total feed amount of the extractant entering the extraction tower can be guaranteed to change in the same proportion and the composition remains unchanged, thereby ensuring the extraction effect of the extraction tower.

[0087] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention are within the protection scope and disclosure scope of the present invention.

Claims

1. A method for controlling the feed amount and composition of an extractant in an extraction tower, characterized in that: The control method comprises the following steps: The feed of the extraction tower includes the reaction solution to be extracted and the extractant; the feed of the extractant includes the recycled extractant, the first component of the extractant and the second component of the extractant; The relationship between the total amount of the recycled extractant, the first component of the extractant and the second component of the extractant and the amount of the reaction solution fed is as shown in formula (1): FT 02 +FT 03 +FT 04 =k×FT 01 ; (1) Among them: FT 02 Indicates the feed amount of recycled extractant, FT 02 ≥0; FT 03 Indicates the feed amount of the first component of the extractant, FT 03 ≥0; FT 04 Indicates the feed amount of the second component of the extractant, FT 04 ≥0; FT 01 represents the feed amount of the reaction liquid; k represents the ratio coefficient of the total feed amount of the extractant to the feed amount of the reaction liquid, and k is 0.1-10; The relationship between the recycled extractant, the first extractant component and the second extractant component is shown in formula (2) and formula (3): Where: C RA Indicates the concentration of the first component of the extractant in the recycled extractant; C A Indicates the concentration of the first component of the extractant in the extractant; C RB Indicates the concentration of the second component of the extractant in the recycled extractant; C B represents the concentration of the second component of the extractant in the extractant; The flow rate of the recycled extractant satisfies formula (4): FT 02 ≤FT 02UPLIMIT ; (4) Among them: FT 02UPLIMIT Indicates the upper limit of the flow rate of the recycled extractant; Then, according to formula (1)-formula (4), the feed amount of recycled extractant FT is calculated 02 , the feed amount of the first component of the extractant FT 03 and the feed amount FT of the second component of the extractant 04 , and are used as feed amount setting values ​​for the recycled extractant, the first component of the extractant and the second component of the extractant, respectively, and are adjusted through the control loop.

2. The control method according to claim 1, characterized in that: The calculation of the recycled extractant feed amount FT 02 To satisfy the conditions of equations (1) to (4), calculate the maximum value of the feed amount of the recycled extractant, max FT: 02 .

3. The control method according to claim 1 or 2, characterized in that: The feed pipeline of the extraction tower includes a reaction liquid feed pipeline and an extractant feed pipeline, and the extractant feed pipeline includes a recycled extractant feed pipeline, an extractant first component feed pipeline and an extractant second component feed pipeline arranged in parallel.

4. The control method according to claim 3, characterized in that: The reaction liquid feeding pipeline is provided with a first flow meter, a first flow controller and a first flow regulating valve.

5. The control method according to claim 3 or 4, characterized in that: The recycled extractant feed pipeline is provided with a second flow meter, a second flow controller and a second flow regulating valve.

6. The control method according to claim 5, characterized in that: The recycled extractant feed pipeline is also provided with an extractant composition online analyzer for online measuring the concentration C of the first component of the extractant in the recycled extractant. RA The concentration of the second component of the extractant in the recycled extractant C RB .

7. The control method according to any one of claims 3 to 6, characterized in that: The extractant first component feed pipeline is provided with a third flow meter, a third flow controller and a third flow regulating valve.

8. The control method according to any one of claims 3 to 7, characterized in that: The extractant second component feed pipeline is provided with a fourth flow meter, a fourth flow controller and a fourth flow regulating valve.

9. The control method according to any one of claims 1 to 8, characterized in that: The discharge pipeline of the extraction tower comprises an extraction phase discharge pipeline connected to the top of the extraction tower and a raffinate phase discharge pipeline connected to the bottom of the extraction tower.

10. The control method according to any one of claims 1 to 9, characterized in that: The control method comprises the following steps: The feed of the extraction tower includes the reaction solution to be extracted and the extractant; the feed of the extractant includes the recycled extractant, the first component of the extractant and the second component of the extractant; The relationship between the total amount of the recycled extractant, the first component of the extractant and the second component of the extractant and the amount of the reaction solution fed is as shown in formula (1): FT 02 +FT 03 +FT 04 =k×FT 01 ; (1) Among them: FT 02 Indicates the feed amount of recycled extractant, FT 02 ≥0; FT 03 Indicates the feed amount of the first component of the extractant, FT 03 ≥0; FT 04 Indicates the feed amount of the second component of the extractant, FT 04 ≥0; FT 01 represents the feed amount of the reaction liquid; k represents the ratio coefficient of the total feed amount of the extractant to the feed amount of the reaction liquid, and k is 0.1-10; The relationship between the recycled extractant, the first extractant component and the second extractant component is shown in formula (2) and formula (3): Where: C RA Indicates the concentration of the first component of the extractant in the recycled extractant; C A Indicates the concentration of the first component of the extractant in the extractant; C RB Indicates the concentration of the second component of the extractant in the recycled extractant; C B represents the concentration of the second component of the extractant in the extractant; The flow rate of the recycled extractant satisfies formula (4): FT 02 ≤FT 02UP LIMIT; (4) Among them: FT 02UPLIMIT Indicates the upper limit of the flow rate of the recycled extractant; Then, according to formula (1)-formula (4), the maximum value of the recycled extractant feed amount max FT is calculated 02 , the feed amount of the first component of the extractant FT 03 and the feed amount FT of the second component of the extractant 04 , and are used as feed amount setting values ​​of the recycled extractant, the first component of the extractant, and the second component of the extractant, respectively, and are adjusted through the control loop; The feed pipeline of the extraction tower includes a reaction liquid feed pipeline and an extractant feed pipeline, and the extractant feed pipeline includes a recycled extractant feed pipeline, a first component extractant feed pipeline and a second component extractant feed pipeline arranged in parallel; The reaction liquid feed pipeline is provided with a first flow meter, a first flow controller and a first flow regulating valve; the recycled extractant feed pipeline is provided with a second flow meter, a second flow controller, a second flow regulating valve and an extractant composition online analyzer, and the extractant composition online analyzer is used to online measure the concentration C of the first component of the extractant in the recycled extractant. RA The concentration of the second component of the extractant in the recycled extractant C RB The first component of the extractant feed pipeline is provided with a third flow meter, a third flow controller and a third flow regulating valve; the second component of the extractant feed pipeline is provided with a fourth flow meter, a fourth flow controller and a fourth flow regulating valve; The discharge pipeline of the extraction tower comprises an extraction phase discharge pipeline connected to the top of the extraction tower and a raffinate phase discharge pipeline connected to the bottom of the extraction tower.

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