A method for extracting fluorine from nickel-cobalt-manganese sulfate solution

Abstract

This application discloses a method for extracting fluorine from a nickel-cobalt-manganese sulfate solution, relating to the field of wastewater treatment. The method comprises the following steps: mixing the nickel-cobalt-manganese sulfate solution with concentrated sulfuric acid for activation, subjecting the activated solution to multi-stage countercurrent extraction using an organic phase comprising tributyl phosphate, isooctyl alcohol, and a diluent, subjecting the fluorine-containing organic phase to multi-stage countercurrent washing, and subjecting the washed fluorine-containing organic phase to multi-stage countercurrent stripping. This application, directed to the extraction of fluorine from a nickel-cobalt-manganese sulfate solution, employs tributyl phosphate as an extractant, while isooctyl alcohol is added in a mixing and settling tank to improve phase separation. The process is simple, and the extraction rate is as high as over 90%.

Description

Technical Field

[0001] The present application relates to the field of wastewater treatment, and in particular to a method for extracting fluorine from a nickel-cobalt-manganese sulfate solution. Background Art

[0002] Industrial production often uses precipitation to remove calcium, magnesium, and aluminum from recycled battery powder or electrode powder. During this process, fluorine-containing materials are added, introducing fluoride ion impurities and forming a fluorine-containing solution. Fluorine in this solution often exists in the form of fluorosilicic acid or hydrofluoric acid. The presence of fluorine can be detrimental to subsequent production and equipment, making its removal crucial.

[0003] At present, my country mainly uses chemical precipitation, ion resin exchange, activated carbon adsorption and coagulation sedimentation methods to reduce fluoride in fluoride-containing solutions. However, the chemical precipitation method has a long reaction time, produces a lot of sludge and has poor treatment accuracy; the ion exchange method has a long treatment cycle, a large treatment system, and high process parameter requirements. A large amount of wastewater needs to be treated during resin regeneration; the activated carbon adsorption method cannot be regenerated after adsorption saturation, and the cost is high; the coagulation sedimentation method will introduce aluminum, and the aluminum content often exceeds the standard.

[0004] In summary, the current methods for removing fluorine from nickel-cobalt-manganese sulfate solutions have many shortcomings, and there is an urgent need to develop a method that is simple in process and highly efficient in removing fluorine from the solution. Summary of the Invention

[0005] The present application provides a method for extracting fluorine from a nickel-cobalt-manganese sulfate solution. To address the current problems of low efficiency and complex procedures in fluorine separation and extraction, a method for deep fluorine removal from a nickel-cobalt-manganese sulfate solution is provided, which has high selectivity for fluoride ions, high extraction rate, good separation effect, and simple process.

[0006] In order to solve the above technical problems, the present application provides a method for extracting fluorine from a nickel-cobalt-manganese sulfate solution, comprising the following steps:

[0007] The nickel-cobalt-manganese sulfate solution and concentrated sulfuric acid are mixed for activation to obtain an activated feed solution;

[0008] In a mixing and settling tank, an organic phase is used to perform multi-stage countercurrent extraction on the activated liquid to obtain a fluorine-containing organic phase and a raffinate liquid, wherein the organic phase comprises 60-80 wt% of tributyl phosphate, 5-25 wt% of isooctyl alcohol, and the remainder is a diluent;

[0009] The fluorine-containing organic phase is subjected to multi-stage countercurrent washing using a detergent;

[0010] The washed fluorine-containing organic phase is subjected to multi-stage countercurrent stripping using a stripping agent to obtain a stripping solution and an empty organic phase.

[0011] The present application uses tributyl phosphate as an extractant and adds isooctyl alcohol, which can improve phase separation in the mixing and settling tank. Due to the strong stirring intensity and continuous operation of the mixing and settling tank, if isooctyl alcohol is not added during the clarification process after stirring, the organic phase cannot be completely separated, resulting in excessive feed liquid being mixed with the organic phase after extraction, so that the organic phase that is not completely separated during the washing process enters the stripping step to produce a large amount of nickel, cobalt and manganese precipitation. The addition of isooctyl alcohol improves the phase separation effect of the extraction and washing sections, shortens the phase separation time, and avoids the generation of precipitation during the stripping process. In addition, the present application activates the feed liquid in advance, converts free fluoride ions into hydrogen fluoride and destroys fluorine-containing metal complexes, so that the feed liquid generates hydrogen fluoride that can be extracted by tributyl phosphate, which can avoid acidification of the organic phase during extraction, thereby reducing the generation of waste liquid. Since hydrogen fluoride will gradually convert into hydrogen ions and fluoride ions in the solution until equilibrium is reached, it is necessary to immediately undergo an extraction reaction with the organic phase, further avoiding the addition of an activator, the process steps are simple, the extraction rate can even be as high as 90% or more, and the separation effect of fluorine element in the solution is good.

[0012] In a specific embodiment, the diluent is at least one of sulfonated kerosene, benzene, toluene, and carbon tetrachloride.

[0013] In a specific embodiment, the concentration of concentrated sulfuric acid during the activation process is 10-19 mol / L, and the molar content of hydrogen in the concentrated sulfuric acid is 2-6 times the molar content of fluorine in the nickel-cobalt-manganese sulfate solution.

[0014] In the present application, concentrated sulfuric acid is added to the nickel-cobalt-manganese sulfate solution. Adding a sufficient amount of concentrated sulfuric acid can improve the extraction effect, convert free fluoride ions into hydrogen fluoride and destroy fluorine-containing metal complexes. The use of concentrated sulfuric acid can avoid the concentration of sulfuric acid being too low to dilute the concentration of fluorine in the feed solution, thereby causing the fluorine concentration to decrease and become difficult to enrich, affecting the extraction rate.

[0015] In a specific embodiment, the silicon concentration in the nickel-cobalt-manganese sulfate solution is below 0.25 g / L.

[0016] The presence of silicon in the raw material solution will affect the extraction rate of tributyl phosphate. This is because the presence of silicon will form a complex with fluorine, affecting the extraction rate. Controlling the silicon concentration within a lower range can ensure a higher extraction rate.

[0017] In a specific embodiment, the nickel cobalt manganese sulfate solution includes 20-40 g / L nickel, 2-8 g / L cobalt, 2-10 g / L manganese, 15-25 g / L sodium, 0-0.25 g / L silicon, and 1-3 g / L fluorine.

[0018] In a specific embodiment, in the multi-stage countercurrent extraction process, the extraction phase ratio O / A is (1-3): (1-3), the number of multi-stage countercurrent extraction stages is 4-7, and the reaction temperature is 5-90°C.

[0019] In a specific embodiment, during the multi-stage countercurrent extraction process, the reaction temperature is 5-50° C., and the higher the temperature, the lower the extraction rate.

[0020] In a specific embodiment, the stripping agent is a 0.5-1 mol / L sodium hydroxide solution.

[0021] This application utilizes an alkaline stripping agent to strip fluoride ions from the organic phase. Compared with sodium carbonate solution, the stripping agent is sodium hydroxide solution, which can avoid the risk of bubbles forming in the tank after mixing with the fluorine-loaded organic phase.

[0022] In a specific embodiment, the detergent is a 0.1-0.2 mol / L sulfuric acid solution.

[0023] In a specific embodiment, the unloaded organic phase is subjected to multi-stage countercurrent washing with water to dissolve and separate the residual stripping agent.

[0024] In a specific embodiment, during the multi-stage countercurrent washing process of the unloaded organic phase with water, the washing water is recycled, and new water is used when the pH of the water reaches above 10 after washing.

[0025] In a specific embodiment, during the multi-stage countercurrent extraction process, the reaction speed is 150-500 rpm, and the reaction time is 0.05-0.1 h.

[0026] In a specific embodiment, during the multi-stage countercurrent washing process of the fluorine-containing organic phase, the washing phase ratio O / A is (6-9):1, the number of stages of the multi-stage countercurrent washing is 4-7, the reaction temperature is 5-90°C, the reaction speed is 150-500rpm, and the reaction time is 0.05-0.1h.

[0027] In a specific embodiment, in the multi-stage countercurrent stripping process, the stripping phase ratio O / A is (3-9):1, the number of stages of the multi-stage countercurrent stripping is 3-5, the reaction temperature is 5-90°C, the reaction speed is 150-500rpm, and the reaction time is 0.05-0.1h.

[0028] In a specific embodiment, during the multi-stage countercurrent washing process of the unloaded organic phase, the washing phase ratio O / A is (2-3):1, the number of stages of the multi-stage countercurrent washing is 2-3, the reaction temperature is 5-90°C, the reaction speed is 150-500rpm, and the reaction time is 0.05-0.1h.

[0029] Compared with the existing technology, this application has the following beneficial effects:

[0030] The present application aims at extracting fluorine from nickel-cobalt-manganese sulfate solution, using tributyl phosphate as an extractant and adding isooctyl alcohol at the same time, which can improve phase separation in the mixing and settling tank, activate the feed liquid in advance, and make the feed liquid generate hydrogen fluoride that can be extracted by tributyl phosphate. It can avoid acidification of the organic phase during extraction, thereby reducing the generation of waste liquid. The process steps are simple, the extraction rate is as high as more than 90%, and the separation effect of the fluorine element in the solution is good. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 : This is a flow chart of a method for extracting fluorine from a nickel-cobalt-manganese sulfate solution in an embodiment of the present application. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0033] Example 1

[0034] A method for extracting fluorine from a nickel-cobalt-manganese sulfate solution comprises the following steps:

[0035] (1) preparing an organic phase according to 80 wt% TBP (tributyl phosphate), 10 wt% isooctyl alcohol, and 10 wt% sulfonated kerosene;

[0036] (2) taking a nickel-cobalt-manganese sulfate solution as a feed solution and adding sulfuric acid with a concentration of 18.4 mol / L for activation, wherein the nickel-cobalt-manganese sulfate solution contains 38.9305 g / L of nickel, 4.6861 g / L of cobalt, 6.7007 g / L of manganese, 20.6441 g / L of sodium, 0.1601 g / L of silicon, and 1.62731 g / L of fluorine, and the molar content of hydrogen in the sulfuric acid is 3 times the molar content of fluorine in the feed solution, to obtain an activated feed solution;

[0037] (3) According to the extraction phase O / A = 3:1, a four-stage countercurrent extraction was carried out in a mixing and settling tank using an organic phase to activate the feed liquid. The extraction reaction temperature was 50 ° C, the rotation speed was 300 rpm, and the time was 5 min. The final fluorine concentration in the raffinate was 65 mg / L, and the extraction rate was 96%;

[0038] (4) using a 0.2 mol / L sulfuric acid solution and a washing phase ratio of O / A = 6:1, the fluorinated organic phase obtained in step (3) was subjected to a four-stage countercurrent washing at a reaction temperature of 50° C., a rotation speed of 300 rpm, and a time of 5 min;

[0039] (5) using 0.6 mol / L sodium hydroxide solution and a stripping ratio O / A=3:1, the fluorine-containing organic phase solution after washing in step (4) was subjected to a 4-stage stripping process at a reaction temperature of 50°C, a rotation speed of 300 rpm, and a time of 5 min to obtain a stripping solution and an empty organic phase, with a stripping rate of more than 98%;

[0040] (6) The unloaded organic phase was subjected to a second-stage countercurrent washing with pure water, with a washing ratio of O / A = 3:1, a reaction temperature of 50 °C, a rotation speed of 300 rpm, and a time of 5 min to wash away any sodium hydroxide solution that may be carried along. The pure water used for washing can be recycled, and new pure water is used when the pH of the pure water reaches above 10 after washing.

[0041] Example 2

[0042] A method for extracting fluorine from a nickel-cobalt-manganese sulfate solution comprises the following steps:

[0043] (1) preparing an organic phase according to 80 wt% TBP, 5 wt% isooctyl alcohol and 15 wt% sulfonated kerosene;

[0044] (2) taking a nickel-cobalt-manganese sulfate solution as a feed solution and adding sulfuric acid with a concentration of 18.4 mol / L for activation, wherein the nickel-cobalt-manganese sulfate solution contains 34.1183 g / L of nickel, 4.0210 g / L of cobalt, 6.0487 g / L of manganese, 17.9738 g / L of sodium, 0.1465 g / L of silicon, and 2.1037 g / L of fluorine, and the molar content of hydrogen in the sulfuric acid is 3 times the molar content of fluorine in the feed solution, to obtain an activated feed solution;

[0045] (3) According to the extraction phase O / A = 3:1, a four-stage countercurrent extraction was carried out in a mixing and settling tank using an organic phase to activate the feed liquid. The extraction reaction temperature was 50 ° C, the rotation speed was 300 rpm, and the time was 5 min. The final fluorine concentration in the raffinate was 40 mg / L, and the extraction rate was 98%;

[0046] (4) using a 0.2 mol / L sulfuric acid solution and a washing phase ratio of O / A = 6:1, the fluorinated organic phase obtained in step (3) was subjected to a four-stage countercurrent washing at a reaction temperature of 50° C., a rotation speed of 300 rpm, and a time of 5 min;

[0047] (5) using 0.6 mol / L sodium hydroxide solution, the stripping ratio O / A = 3:1, and performing 4-stage stripping on the fluorine-containing organic phase solution after washing in step (4), the reaction temperature is 50 ° C, the rotation speed is 300 rpm, and the time is 5 min to obtain stripping solution and empty organic phase, and the stripping rate is more than 98%;

[0048] (6) The unloaded organic phase was subjected to a second-stage countercurrent washing with pure water, with a washing ratio of O / A = 3:1, a reaction temperature of 50 °C, a rotation speed of 300 rpm, and a time of 5 min to wash away any sodium hydroxide solution that may be carried along. The pure water used for washing can be recycled, and new pure water is used when the pH of the pure water reaches above 10 after washing.

[0049] Example 3

[0050] A method for extracting fluorine from a nickel-cobalt-manganese sulfate solution comprises the following steps:

[0051] (1) preparing an organic phase according to 60 wt% TBP, 20 wt% isooctyl alcohol and 20 wt% sulfonated kerosene;

[0052] (2) taking a nickel-cobalt-manganese sulfate solution as a feed solution and adding sulfuric acid with a concentration of 18.4 mol / L for activation, wherein the nickel-cobalt-manganese sulfate solution contains 20.1811 g / L nickel, 2.5432 g / L cobalt, 3.8063 g / L manganese, 21.4728 g / L sodium, 0.1750 g / L silicon, and 2.3361 g / L fluorine, and the molar content of hydrogen in the sulfuric acid is 3 times the molar content of fluorine in the feed solution, to obtain an activated feed solution;

[0053] (3) According to the extraction phase O / A = 3:1, 7 countercurrent extraction was carried out with the organic phase to the activated liquid in the mixing and settling tank. The extraction reaction temperature was 50 ° C, the rotation speed was 300 rpm, and the time was 5 min. The final fluorine concentration in the raffinate liquid was 67 mg / L, and the extraction rate was 97.1%;

[0054] (4) using a 0.2 mol / L sulfuric acid solution and a washing phase ratio of O / A = 6:1, the fluorinated organic phase obtained in step (3) was subjected to a four-stage countercurrent washing at a reaction temperature of 50° C., a rotation speed of 300 rpm, and a time of 5 min;

[0055] (5) using 0.6 mol / L sodium hydroxide solution, the stripping ratio O / A = 3:1, and performing 4-stage stripping on the fluorine-containing organic phase solution after washing in step (4), the reaction temperature is 50 ° C, the rotation speed is 300 rpm, and the time is 5 min to obtain stripping solution and empty organic phase, and the stripping rate is more than 98%;

[0056] (6) The unloaded organic phase was subjected to a second-stage countercurrent washing with pure water, with a washing ratio of O / A = 3:1, a reaction temperature of 50 °C, a rotation speed of 300 rpm, and a time of 5 min to wash away any sodium hydroxide solution that may be carried along. The pure water used for washing can be recycled, and new pure water is used when the pH of the pure water reaches above 10 after washing.

[0057] Example 4

[0058] A method for extracting fluorine from a nickel-cobalt-manganese sulfate solution comprises the following steps:

[0059] (1) preparing an organic phase according to 60 wt% TBP, 15 wt% isooctyl alcohol and 25 wt% sulfonated kerosene;

[0060] (2) taking a nickel-cobalt-manganese sulfate solution as a feed solution and adding sulfuric acid with a concentration of 18.4 mol / L for activation, wherein the nickel-cobalt-manganese sulfate solution contains 38.7961 g / L of nickel, 4.3731 g / L of cobalt, 6.8561 g / L of manganese, 20.3761 g / L of sodium, 0.1534 g / L of silicon, and 2.4785 g / L of fluorine, and the molar content of hydrogen in the sulfuric acid is 3 times the molar content of fluorine in the feed solution, to obtain an activated feed solution;

[0061] (3) According to the extraction phase O / A = 3:1, a four-stage countercurrent extraction was carried out in a mixing and settling tank using an organic phase to activate the feed liquid. The extraction reaction temperature was 50 ° C, the rotation speed was 300 rpm, and the time was 5 min. The final fluorine concentration in the raffinate was 35 mg / L, and the extraction rate was 98.5%;

[0062] (4) using a 0.2 mol / L sulfuric acid solution and a washing phase ratio of O / A = 6:1, the fluorinated organic phase obtained in step (3) was subjected to a four-stage countercurrent washing at a reaction temperature of 50° C., a rotation speed of 300 rpm, and a time of 5 min;

[0063] (5) using 0.6 mol / L sodium hydroxide solution, the stripping ratio O / A = 3:1, and performing 4-stage stripping on the fluorine-containing organic phase solution after washing in step (4), the reaction temperature is 50 ° C, the rotation speed is 300 rpm, and the time is 5 min to obtain stripping solution and empty organic phase, and the stripping rate is more than 98%;

[0064] (6) The unloaded organic phase was subjected to a second-stage countercurrent washing with pure water, with a washing ratio of O / A = 3:1, a reaction temperature of 50 °C, a rotation speed of 300 rpm, and a time of 5 min to wash away any sodium hydroxide solution that may be carried along. The pure water used for washing can be recycled, and new pure water is used when the pH of the pure water reaches above 10 after washing.

[0065] Example 5

[0066] A method for extracting fluorine from a nickel-cobalt-manganese sulfate solution, wherein each step, the reagents used in each step, and the process parameters are the same as those in Example 1, except that in step (3), the silicon concentration in the nickel-cobalt-manganese sulfate solution is 0 g / L, in step (3), the fluorine concentration in the raffinate liquid is 45 mg / L, and the extraction rate is 97.23%; and in step (5), the stripping rate reaches more than 98%.

[0067] Example 6

[0068] A method for extracting fluorine from a nickel-cobalt-manganese sulfate solution, wherein each step, the reagents used in each step, and the process parameters are the same as those in Example 1, except that in step (3), the silicon concentration in the nickel-cobalt-manganese sulfate solution is 2.5792 g / L, the fluorine concentration in the raffinate liquid is 0.5475 g / L, and the extraction rate is 66.36%; and in step (5), the stripping rate reaches over 98%.

[0069] Example 7

[0070] A method for extracting fluorine from a nickel-cobalt-manganese sulfate solution, wherein each step, the reagents used in each step, and the process parameters are the same as those in Example 1, except that in step (3), the extraction phase ratio O / A=1:3, the fluorine concentration in the raffinate liquid is 0.9899 g / L, and the extraction rate is 39.17%; and in step (5), the stripping rate reaches more than 96%.

[0071] Example 8

[0072] A method for extracting fluorine from a nickel-cobalt-manganese sulfate solution, wherein each step, the reagents used in each step, and the process parameters are the same as those in Example 1, except that in step (3), the extraction phase ratio O / A=1:1, the fluorine concentration in the raffinate liquid is 0.5847 g / L, and the extraction rate is 64.07%; and in step (5), the stripping rate reaches more than 97%.

[0073] Embodiment 9

[0074] A method for extracting fluorine from a nickel-cobalt-manganese sulfate solution, wherein each step, the reagents used in each step, and the process parameters are the same as those in Example 1, except that in step (3), the extraction reaction temperature is 20°C, the fluorine concentration in the raffinate liquid is 63 mg / L, and the extraction rate is 96.13%; and in step (5), the stripping rate reaches over 98%.

[0075] Example 10

[0076] A method for extracting fluorine from a nickel-cobalt-manganese sulfate solution, wherein each step, the reagents used in each step, and the process parameters are the same as those in Example 1, except that in step (3), the extraction reaction temperature is 60° C., the fluorine concentration in the raffinate liquid is 0.2731 g / L, and the extraction rate is 83.22%; and in step (5), the stripping rate reaches over 97%.

[0077] Example 11

[0078] A method for extracting fluorine from a nickel-cobalt-manganese sulfate solution, wherein each step, the reagents used in each step, and the process parameters are the same as those in Example 1, except that, in step (2), sulfuric acid with a concentration of 10 mol / L is added to the nickel-cobalt-manganese sulfate solution for activation; in step (3), the fluorine concentration in the raffinate liquid is 89 mg / L, and the extraction rate is 94.53%; and in step (5), the stripping rate reaches over 98%.

[0079] Comparative Example 1

[0080] A method for extracting fluorine from a nickel-cobalt-manganese sulfate solution, wherein each step, the reagents used in each step, and the process parameters are the same as those in Example 1, except that, in step (1), n-octanol is used instead of isooctyl alcohol; in step (3), the fluorine concentration in the raffinate liquid is 91 mg / L, and the extraction rate is 94.41%; in step (4), phase separation difficulties occur in the clarification chamber during the washing process; and in step (5), a large amount of precipitation is generated during the stripping process, making continuous operation impossible.

[0081] Comparative Example 2

[0082] A method for extracting fluorine from a nickel-cobalt-manganese sulfate solution, wherein each step, the reagents used in each step, and the process parameters are the same as those in Example 1, except that in step (1), tri-n-octylamine is used instead of TBP; in step (3), the fluorine concentration in the raffinate liquid is 1.2433 g / L, and the extraction rate is 23.60%; and in step (5), the stripping rate reaches over 97%.

[0083] Comparative Example 3

[0084] A method for extracting fluorine from a nickel-cobalt-manganese sulfate solution, wherein each step, the reagents used in each step, and the process parameters are the same as those in Example 1, except that in step (1), the organic phase is 80 wt% TBP+20 wt% sulfonated kerosene, in step (3), the fluorine concentration in the raffinate liquid is 45 mg / L, and the extraction rate is 97.23%, in step (4), phase separation difficulties occur in the clarification chamber during the washing process, and in step (5), a large amount of precipitation is generated during the stripping process, making continuous operation impossible.

[0085] Comparative Example 4

[0086] A method for extracting fluorine from a nickel-cobalt-manganese sulfate solution, wherein each step, the reagents used in each step, and the process parameters are the same as those in Example 1, except that in step (1), the content of isooctyl alcohol and sulfonated kerosene in the organic phase is 0, in step (3), the fluorine concentration in the raffinate liquid is 19.3 mg / L, and the extraction rate is 98.8%, in step (4), phase separation difficulties occur in the clarification chamber during the washing process, and in step (5), a large amount of precipitation is generated during the stripping process, making continuous operation impossible.

[0087] Comparative Example 5

[0088] A method for extracting fluorine from a nickel-cobalt-manganese sulfate solution, wherein each step, the reagents used in each step, and the process parameters are the same as those in Example 1, except that in step (1), the organic phase comprises 60 wt% TBP, 30 wt% isooctyl alcohol, and 10 wt% sulfonated kerosene; in step (3), the fluorine concentration in the raffinate liquid is 797 mg / L, and the extraction rate is 49%; and in step (5), the stripping rate reaches over 96%.

[0089] The specific embodiments described above further illustrate the purpose, technical solutions and beneficial effects of the present application in detail. It should be understood that the above description is only a specific embodiment of the present application and is not intended to limit the scope of protection of the present application.

Claims

1. A method for extracting fluorine from nickel-cobalt-manganese sulfate solution, characterized in that: The following steps are involved: The nickel-cobalt-manganese sulfate solution and concentrated sulfuric acid are mixed for activation to obtain an activated feed solution; In a mixing and settling tank, an organic phase is used to perform multi-stage countercurrent extraction on the activated liquid to obtain a fluorine-containing organic phase and a raffinate liquid, wherein the organic phase comprises 60-80 wt% of tributyl phosphate, 5-25 wt% of isooctyl alcohol, and the remainder is a diluent; The fluorine-containing organic phase is subjected to multi-stage countercurrent washing using a detergent; The washed fluorine-containing organic phase is subjected to multi-stage countercurrent stripping using a stripping agent to obtain a stripping solution and an empty organic phase; The silicon concentration in the nickel-cobalt-manganese sulfate solution is below 0.25 g / L; In the multi-stage countercurrent extraction process, the extraction phase ratio O / A is (1-3):1, the number of multi-stage countercurrent extraction stages is 4-7, and the reaction temperature is 5-90°C.

2. The method for extracting fluorine from a nickel-cobalt-manganese sulfate solution according to claim 1, characterized in that: The diluent is at least one of sulfonated kerosene, benzene, toluene and carbon tetrachloride.

3. The method for extracting fluorine from a nickel-cobalt-manganese sulfate solution according to claim 1, characterized in that: The concentration of concentrated sulfuric acid during the activation process is 10-19 mol / L, and the molar content of hydrogen in the concentrated sulfuric acid is 2-6 times the molar content of fluorine in the nickel-cobalt-manganese sulfate solution.

4. The method for extracting fluorine from a nickel-cobalt-manganese sulfate solution according to claim 1, wherein: The nickel-cobalt-manganese sulfate solution includes 20-40 g / L nickel, 2-8 g / L cobalt, 2-10 g / L manganese, 15-25 g / L sodium, 0-0.25 g / L silicon, and 1-3 g / L fluorine.

5. The method for extracting fluorine from a nickel-cobalt-manganese sulfate solution according to claim 1, characterized in that: In the multi-stage countercurrent extraction process, the reaction temperature is 5-50°C.

6. The method for extracting fluorine from a nickel-cobalt-manganese sulfate solution according to claim 1, characterized in that: The stripping agent is 0.5-1 mol / L sodium hydroxide solution.

7. The method for extracting fluorine from a nickel-cobalt-manganese sulfate solution according to claim 1, characterized in that: The detergent is a 0.1-0.2 mol / L sulfuric acid solution.

8. The method for extracting fluorine from a nickel-cobalt-manganese sulfate solution according to claim 1, wherein: The empty organic phase was washed with water in a multi-stage countercurrent manner.

9. The method for extracting fluorine from a nickel-cobalt-manganese sulfate solution according to claim 8, characterized in that: During the multi-stage countercurrent washing process of the unloaded organic phase with water, the washing water is recycled, and new water is used when the pH of the water reaches above 10 after washing.

10. The method for extracting fluorine from a nickel-cobalt-manganese sulfate solution according to claim 1, characterized in that: In the multi-stage countercurrent extraction process, the reaction speed is 150-500 rpm and the reaction time is 0.05-0.1 h.

11. The method for extracting fluorine from a nickel-cobalt-manganese sulfate solution according to claim 1, wherein: During the multi-stage countercurrent washing process of the fluorine-containing organic phase, the washing phase ratio O / A is (6-9):1, the number of multi-stage countercurrent washing stages is 4-7, the reaction temperature is 5-90°C, the reaction speed is 150-500rpm, and the reaction time is 0.05-0.1h.

12. The method for extracting fluorine from a nickel-cobalt-manganese sulfate solution according to claim 1, wherein: In the multi-stage countercurrent stripping process, the stripping phase O / A ratio is (3-9):1, the number of stages of the multi-stage countercurrent stripping is 3-5, the reaction temperature is 5-90°C, the reaction speed is 150-500rpm, and the reaction time is 0.05-0.1h.

13. The method for extracting fluorine from a nickel-cobalt-manganese sulfate solution according to claim 8, wherein: During the multi-stage countercurrent washing process of the unloaded organic phase, the washing phase ratio O / A is (2-3):1, the number of stages of the multi-stage countercurrent washing is 2-3, the reaction temperature is 5-90°C, the reaction speed is 150-500rpm, and the reaction time is 0.05-0.1h.

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