A method for cationic separation of acidic vanadium solutions

Abstract

The present application belongs to the technical field of cation extraction, and particularly relates to a method for separating cations from an acidic vanadium solution, which comprises the following steps: S1, obtaining the acidic vanadium solution by roasting and acid leaching of vanadium slag; S2, extracting the acidic vanadium solution by selecting an extraction solvent to obtain an oil phase and an aqueous phase; S3, selecting a stripping agent to perform back extraction on the oil phase to obtain a stripping raffinate and a blank organic phase, and collecting the stripping liquid; S4, precipitating the stripping raffinate, drying and calcining to obtain vanadium pentoxide; the extraction solvent comprises an extractant, a diluent and a modifier; the extractant comprises a mixture of one or more of anthraquinone and its derivatives, 1,4-anthracenedione and its derivatives, alkyl phosphonic acid and its derivatives, alkyl phosphine and its derivatives, phosphate ester and its derivatives, quinoline and its derivatives, aliphatic ketone and its derivatives, aliphatic ether and its derivatives, aliphatic amine and its derivatives, aliphatic hydrocarbon and its derivatives, and benzene and its derivatives. The method can greatly improve the recovery rate and purity of cations.

Description

Technical Field

[0001] This invention belongs to the field of cation extraction technology, specifically relating to a method for separating cations from acidic vanadium solutions. Background Technology

[0002] Currently, the "vanadium slag roasting-acid leaching" process has a significant cost advantage in the industry, opening up another avenue for vanadium resource extraction and achieving green vanadium extraction with broad application prospects. However, the acidic vanadium solution produced by this process contains a large number of cations, such as manganese, calcium, magnesium, iron, and titanium. The red vanadium obtained by direct precipitation has a high impurity content, resulting in a relatively limited variety of products manufactured through it and a relatively limited downstream market expansion. Processing acidic vanadium solution into high-purity vanadium series products is difficult due to the large variety and high content of impurity cations, which seriously affects the improvement of vanadium solution purity. Currently, most industries require secondary dissolution and even repeated dissolution and precipitation to remove impurities in order to obtain high-purity vanadium solution for manufacturing various high-purity downstream vanadium products, such as high-purity vanadium, vanadium electrolyte, and ammonium polyvanadate. This process is lengthy, costly, and has low resource utilization, severely restricting the development and promotion of the "vanadium slag roasting-acid leaching" process. Summary of the Invention

[0003] One technical problem to be solved by the present invention is to provide a method for separating cations in acidic vanadium solution, which has a simple process, low cost, can effectively utilize vanadium resources in acidic vanadium solution, and increase the utilization rate of cations in vanadium solution.

[0004] To solve the above-mentioned technical problems, the present invention provides a method for cation separation in acidic vanadium solution, comprising the following steps:

[0005] S1. Vanadium slag is roasted and then acid-leached to obtain acidic vanadium solution.

[0006] S2. An extraction solvent is selected to extract the acidic vanadium solution, yielding an oil phase and an aqueous phase;

[0007] S3. Select a back-extraction agent to back-extract the oil phase, obtain back-extraction residue and blank organic phase, and collect the back-extraction residue;

[0008] S4. The precipitate and back-extracted residue is dried and calcined to obtain vanadium pentoxide;

[0009] The extraction solvent includes: an extractant, a diluent, and a modifier;

[0010] The extractant comprises one or more of the following: anthraquinones and their derivatives, 1,4-anthraquinones and their derivatives, alkylphosphonic acids and their derivatives, alkylphosphines and their derivatives, phosphate esters and their derivatives, quinoline and their derivatives, fatty ketones and their derivatives, fatty ethers and their derivatives, fatty amines and their derivatives, fatty hydrocarbons and their derivatives, and benzene and its derivatives.

[0011] In some embodiments, the extractant comprises one or more of the following: anthraquinones and their derivatives, 1,4-anthraquinones and their derivatives, alkylphosphonic acids and their derivatives, phosphate esters and their derivatives, quinolines and their derivatives, and fatty ethers and their derivatives.

[0012] In some embodiments, the anthraquinones and their derivatives comprise the structure of formula (I):

[0013]

[0014] (I);

[0015] R1 to R8 are independently selected from H and C1 to C. 16 Alkyl groups, -OH groups, -X groups;

[0016] X is selected from F, Cl, or Br;

[0017] The 1,4-anthradinone and its derivatives comprise the structure of formula (II):

[0018]

[0019] (II);

[0020] R1 to R9 are independently selected from H and C1 to C. 16 Alkyl groups, -OH groups, -X groups;

[0021] X is selected from F, Cl, or Br.

[0022] In some embodiments, the extractant comprises one or more of the following: 2-ethylhexyl phosphate, diisooctyl phosphate, bis(2,4,4-trimethylpentyl)phosphonic acid, 9,10-anthraquinone, 1,4-anthradinone, 2-methylanthraquinone, 2,6-dihydroxyanthraquinone, 1-hydroxyanthraquinone, 2-tert-butylanthraquinone, and 1,5-dibromoanthra-9,10-dione.

[0023] In some embodiments, the modifier includes tributyl phosphate.

[0024] In some embodiments, the diluent includes one or more of the following: kerosene, sulfonated kerosene, 260# solvent oil, acetone oxime, methanol, and ethyl acetate.

[0025] In some embodiments, the stripping agent includes one or more of sulfuric acid, hydrochloric acid, nitric acid, phosphoric acid, oxalic acid, ethanol, ammonium carbonate, ammonium chloride, and ammonium nitrate.

[0026] In some embodiments, the amount of extraction solvent used during extraction is controlled at 10% to 50% of the oil phase volume, the volume ratio of oil phase to water phase is controlled at (0.5:1) to (2:1), the pH of the system is controlled at 1.0 to 2.5, the time is controlled at 8 to 10 min, and the temperature is controlled at 15 to 30°C.

[0027] In some embodiments, the concentration of the back-extractant is in the range of 0.5 to 5.0 mol / L, the volume ratio of the blank organic phase to the back-extractant is controlled at (0.5:1) to (2:1), the time is controlled at 8 to 10 min, and the temperature is controlled at 15 to 30°C.

[0028] In some embodiments, the acidic vanadium solution in S1 further undergoes a filtration step and / or a settling step. The filtration step includes filtration after adding a flocculant or direct filtration. The filtration step uses a precision filter, a centrifugal filter, or a membrane filter. The settling time in the settling step is ≥6 hours.

[0029] The beneficial effects of this invention include at least the following: This invention uses a specific extractant to extract cations from acidic vanadium solution, with the aim of enriching most or all of the cations in the oil phase while leaving the anions in the aqueous phase, thus achieving the separation of cations and anions. After extraction with the extractant of this invention, a suitable back-extraction agent is used to back-extract the extracted oil phase. With specific back-extraction conditions, cations can be effectively extracted from the acidic vanadium solution. The method of this invention can greatly improve the recovery rate of cations and realize the resource-based extraction of elements. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0031] Figure 1 A flowchart of the extraction steps provided in some embodiments of the present invention is shown. Detailed Implementation

[0032] The embodiments of the present invention will be further described in detail below with reference to the accompanying drawings and examples. The detailed description of the following embodiments and the accompanying drawings are used to illustrate the principles of the present invention by way of example, but should not be used to limit the scope of the present invention. The present invention can be implemented in many different forms and is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

[0033] These embodiments are provided to make the invention thorough and complete, and to fully express the scope of the invention to those skilled in the art. It should be noted that, unless otherwise specifically stated, the relative arrangements of components illustrated in these embodiments should be interpreted as merely exemplary and not as limiting.

[0034] In this invention, the term "TBP" refers to tributyl phosphate.

[0035] In this invention, the term "P507" refers to 2-ethylhexyl phosphate (2-ethylhexyl ester).

[0036] In this invention, the term "P204" refers to diisooctyl phosphate;

[0037] In this invention, the term "Cyanex272" refers to bis(2,4,4-trimethylpentyl)phosphonic acid;

[0038] In this invention, the term "comparison" refers to the volume ratio of the oil phase (organic phase) to the aqueous phase (inorganic phase);

[0039] In this invention, words such as "comprising" or "including" mean that the element preceding the word covers the element listed after the word, and does not exclude the possibility that it may also cover other elements.

[0040] In this invention, three-stage extraction means mixing acidic vanadium solution with extraction solvent and performing three extractions; four-stage extraction means four extractions, and so on.

[0041] In this invention, the term "controlled at" includes endpoint values.

[0042] All terms used in this invention have the same meaning as understood by one of ordinary skill in the art to which this invention pertains, unless otherwise specifically defined. It should also be understood that terms defined in general dictionaries should be interpreted as having meanings consistent with their meanings in the context of the relevant art, and not as idealized or highly formalized, unless expressly defined herein.

[0043] Technologies and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such technologies and equipment should be considered part of the instruction manual.

[0044] like Figure 1As shown, in some embodiments, the present invention provides a method for separating cations from acidic vanadium solutions, comprising the following steps:

[0045] S1. Vanadium slag is roasted and then acid-leached to obtain acidic vanadium solution.

[0046] S2. An extraction solvent is selected to extract the acidic vanadium solution, yielding an oil phase and an aqueous phase;

[0047] S3. Select a back-extraction agent to back-extract the oil phase, obtain back-extraction residue and blank organic phase, and collect the back-extraction residue;

[0048] S4. The precipitate and back-extracted residue is dried and calcined to obtain vanadium pentoxide;

[0049] Extraction solvents include: extractants, diluents, and modifiers;

[0050] The extractant includes one or more of the following: anthraquinones and their derivatives, 1,4-anthraquinones and their derivatives, alkylphosphonic acids and their derivatives, alkylphosphines and their derivatives, phosphate esters and their derivatives, quinolines and their derivatives, fatty ketones and their derivatives, fatty ethers and their derivatives, fatty amines and their derivatives, fatty hydrocarbons and their derivatives, and benzene and its derivatives.

[0051] This invention utilizes specific extractants, particularly anthraquinone extractants, which, due to their unique chemical structure, selectively extract only vanadium ions from the solvent, with limited extraction of other ions. This selectivity is superior to traditional extractants, resulting in a higher purity of recovered vanadium pentoxide. The extractant used in this invention extracts cations from acidic vanadium solutions, aiming to enrich most or all of the cations in the oil phase while leaving anions in the aqueous phase, thus achieving cation-anion separation. After extraction, a suitable back-extraction agent is used to back-extract the oil phase under specific conditions, effectively extracting cations from the acidic vanadium solution. This method significantly improves cation recovery, enabling resource-based extraction of elements. Furthermore, this method significantly improves cation recovery, achieving resource-based extraction of elements and yielding high-value-added byproducts. In some embodiments of this invention, the vanadium recovery rate reaches over 97%.

[0052] In some embodiments of the present invention, the extractant comprises one or more of the following: anthraquinone and its derivatives, 1,4-anthraquinone and its derivatives, alkylphosphonic acid and its derivatives, phosphate ester and its derivatives, quinoline and its derivatives, and fatty ether and its derivatives.

[0053] The acidic vanadium liquor in this invention refers to the vanadium liquor obtained through the "vanadium slag roasting-acid leaching" process, in which the vanadium element concentration is generally ≥15g / L. This invention mainly extracts vanadium ions with higher content from the acidic vanadium liquor. We will not discuss the recovery of ions with lower concentrations such as manganese, calcium, magnesium, and iron.

[0054] In the acidic vanadium solution of the present invention, the acid used for acid leaching can be concentrated sulfuric acid, or the concentrated sulfuric acid can be diluted in a certain proportion to control the concentration of sulfuric acid solution at 20%~70% (by volume percentage of sulfuric acid in the solution), which is more cost-effective.

[0055] In some embodiments of the present invention, the vanadium concentration in the acidic vanadium solution can be 15 g / L, 20 g / L, or 25 g / L.

[0056] In some embodiments of the present invention, anthraquinones and their derivatives comprise structures of the following formula (I):

[0057]

[0058] (I);

[0059] R1 to R8 are independently selected from H and C1 to C. 16 Alkyl groups, -OH groups, -X groups;

[0060] X is selected from F, Cl, or Br;

[0061] C1~C 16 The alkyl groups include, but are not limited to, straight-chain or branched alkyl groups comprising C1, C2, C3, C4, C5, C6, C7, C8, C9, C10, C11, C12, C13, C14, C15 or C16.

[0062] 1,4-Anthrone and its derivatives include structures of the following formula (II):

[0063]

[0064] (II);

[0065] R1 to R9 are independently selected from H and C1 to C. 16 Alkyl groups, -OH groups, -X groups;

[0066] X is selected from F, Cl, or Br;

[0067] C1~C 16 The alkyl groups include, but are not limited to, straight-chain or branched alkyl groups comprising C1, C2, C3, C4, C5, C6, C7, C8, C9, C10, C11, C12, C13, C14, C15 or C16.

[0068] In some embodiments of the present invention, the extractant comprises one or more of the following: 2-ethylhexyl phosphate, diisooctyl phosphate, bis(2,4,4-trimethylpentyl)phosphonic acid, 9,10-anthraquinone, 1,4-anthradinone, 2-methylanthraquinone, 2,6-dihydroxyanthraquinone, 1-hydroxyanthraquinone, 2-tert-butylanthraquinone, and 1,5-dibromoanthra-9,10-dione.

[0069] In some embodiments of the present invention, the modifier includes: tributyl phosphate.

[0070] This invention incorporates a specific modifier, the main purpose of which is to prevent the formation of a third phase during the extraction process, which would make it impossible to separate the organic phase from the liquid phase. At the same time, the addition of the modifier can effectively reduce the separation time between the organic phase and the liquid phase.

[0071] In some embodiments of the present invention, the diluent includes one or more of the following: kerosene, sulfonated kerosene, 260# solvent oil, acetone oxime, methanol, and ethyl acetate.

[0072] In some embodiments of the present invention, the back-extraction agent includes one or more of the following: sulfuric acid, hydrochloric acid, nitric acid, phosphoric acid, oxalic acid, ethanol, ammonium carbonate, ammonium chloride, and ammonium nitrate.

[0073] In some embodiments, sulfuric acid is selected as the stripping agent to better extract cations from acidic vanadium solutions. In practical applications, dilute sulfuric acid is often used, with a concentration range of 0.5 to 5.0 mol / L.

[0074] In some embodiments of the present invention, the amount of extraction solvent used during extraction is controlled at 10% to 50% of the oil phase; the ratio of the oil phase to the aqueous phase during extraction is controlled at (0.5:1) to (2:1) (for example, it can be 0.5:1, 1:1, 1.5:1 or 2:1); the pH of the system during extraction is controlled at 1.0 to 2.5 (for example, the pH can be 1.0, 1.2, 1.5, 1.8, 2.0, 2.2 or 2.5); the extraction time is controlled at 8 to 10 min (for example, it can be 8 min, 9 min or 10 min); and the extraction temperature is controlled at 15 to 30°C (for example, it can be 15°C, 20°C, 25°C or 30°C).

[0075] This invention further improves the extraction of cations from vanadium solution by using appropriate back-extraction conditions.

[0076] In some embodiments of the present invention, the concentration of the back-extractant is in the range of 0.5 to 5.0 mol / L, the volume ratio of the blank organic phase to the back-extractant is controlled at (0.5:1) to (2:1) (for example, it can be 0.5:1, 1:1, 1.5:1 or 2:1), the time is controlled at 8 to 10 min (for example, it can be 8 min, 9 min or 10 min), and the temperature is controlled at 15 to 30°C (for example, it can be 15°C, 20°C, 25°C or 30°C).

[0077] In order to better eliminate the interference of impurities, in some embodiments of the present invention, the acidic vanadium solution in S1 also undergoes a filtration step and / or a settling step. The filtration step includes filtration after adding flocculant or direct filtration. The filtration step uses a precision filter, a centrifugal filter or a membrane filter. The settling time of the settling step is ≥6 hours.

[0078] The present invention will be described in detail below through embodiments, but the scope of protection of the present invention is not limited thereto.

[0079] Example 1

[0080] In this embodiment, the extraction solvent consists of extractant 9,10-anthraquinone, diluent kerosene, and modifier TBP, wherein the volume percentages of extractant 9,10-anthraquinone, diluent kerosene, and modifier TBP account for 30%, 5%, and 65% of the total volume percentage of the extractant, respectively.

[0081] The method in this embodiment includes the following steps:

[0082] S1. After calcination and acid leaching, vanadium slag is used to obtain acidic vanadium solution. S1 includes: S101. Preparation of acidic vanadium solution: After calcination, 2.0 mol / L H2SO4 and 3.0 mol / L NaOH are added to form a first solution, and the pH of the first solution is adjusted to 2.0.

[0083] S102. Add reducing agent Na2SO3 to the first solution, and then stir for 7 min to obtain a solution mainly containing tetravalent vanadium and divalent iron, i.e., acidic vanadium solution; the acidic vanadium solution contains 20 g / L of vanadium;

[0084] S2, extracting the acidic vanadium solution to obtain an oil phase and an aqueous phase, wherein S2 comprises:

[0085] S201. Mix the acidic vanadium solution with the extraction solvent and perform three-stage extraction to obtain a loaded organic phase (oil phase) and raffinate (aqueous phase), wherein the volume ratio of the oil phase to the aqueous phase is 1:1.

[0086] The extraction solvent is a mixture of 9,10-anthraquinone (extractant), kerosene (diluent), and TBP (modifier); wherein 9,10-anthraquinone accounts for 30% of the total volume of the extraction solvent, kerosene accounts for 65% of the total volume of the extraction solvent, and TBP accounts for 5% of the total volume of the extraction solvent; the extraction temperature is 25°C, the volume ratio of the extraction solvent to the acidic vanadium solution is 1:1, the extraction time is 10 min, and the phase separation time is 5 min;

[0087] S202. Wash the above-obtained supported organic phase (oil phase) with deionized water. The volume ratio of the washing liquid to the supported organic phase is 1:1, and the washing temperature is 25°C. Perform one wash.

[0088] S3, Selecting a back-extraction agent to back-extract the oil phase, wherein S3 includes:

[0089] S301. The washed loaded organic phase (oil phase) is back-extracted with H2SO4 solution to obtain back-extraction residue and blank organic phase; the H2SO4 solution used as the back-extraction agent has a concentration of 2.5 mol / L, the back-extraction temperature is 30℃, the volume ratio of the loaded organic phase (oil phase) to the H2SO4 solution during back-extraction is 1:1, the back-extraction time is 10 min, and the phase separation time is 3 min;

[0090] The blank organic phase obtained by back-extraction is recycled as an extraction solvent.

[0091] S4. Add precipitant (NH4)2CO3 to the back-extraction residue. The concentration of the precipitant is 2.5 mol / L. The amount added is based on the molar ratio of (NH4)2CO3 to vanadium in the back-extraction residue of 1.5. After stirring evenly, let it stand to precipitate. After filtering and separating the precipitated solid phase, dry it to remove moisture. Then, introduce oxygen and calcine it at 550℃ for 2.5 h. After calcination, vanadium pentoxide with high purity can be obtained.

[0092] In this embodiment, the vanadium recovery rate in the acidic vanadium solution is 99.8%, and the purity of the vanadium pentoxide obtained after calcination is 99.8%.

[0093] Example 2

[0094] In this embodiment, the extraction solvent consists of the extractant 2-methylanthraquinone, the diluent sulfonated kerosene, and the modifier TBP, wherein the volume percentages of 2-methylanthraquinone, the diluent sulfonated kerosene, and the modifier TBP account for 20%, 75%, and 5% of the total volume percentage of the extractant, respectively.

[0095] Sulfonated kerosene is obtained by sulfonating kerosene with concentrated sulfuric acid.

[0096] The method in this embodiment includes the following steps:

[0097] S1, vanadium slag is roasted and acid-leached to obtain acidic vanadium solution, wherein S1 includes:

[0098] S101. Preparation of acidic vanadium solution: After calcination of vanadium slag, add 2.5 mol / L H2SO4 and 1 mol / L NaOH to form a first solution, and adjust the pH of the first solution to 2.5.

[0099] S102. Add sodium sulfide, a reducing agent, to the first solution and stir for 10 min to obtain a solution mainly containing tetravalent vanadium, i.e., acidic vanadium solution; the acidic vanadium solution contains 20 g / L of vanadium.

[0100] S2, extracting the acidic vanadium solution to obtain an oil phase and an aqueous phase, wherein S2 comprises:

[0101] S201. Mix the acidic vanadium solution with the extraction solvent and perform four-stage extraction to obtain a loaded organic phase (oil phase) and raffinate (aqueous phase); wherein the volume ratio of the oil phase to the aqueous phase is 1:1.

[0102] The extraction solvent is a mixture of 2-methylanthraquinone (extractant), sulfonated kerosene (diluent), and TBP (modifier); wherein 2-methylanthraquinone accounts for 20% of the total volume of the extraction solvent, sulfonated kerosene accounts for 75% of the total volume of the extraction solvent, and TBP accounts for 5% of the total volume of the extraction solvent solution; the extraction temperature is 25°C, the volume ratio of the extraction solvent to the acidic vanadium solution is 1:1, the extraction time is 8 min, and the phase separation time is 3 min;

[0103] S202. Wash the above-obtained supported organic phase (oil phase) with 0.5 mol / L H2SO4 solution. The volume ratio of washing solution to supported organic phase (oil phase) is 1:1. The washing temperature is 25℃. Perform two washes. (The purpose of using H2SO4 solution is to ensure that the vanadium recovered from the oil phase has a high purity, as some other ions are entrained in the oil phase during the phase separation process.)

[0104] S3, Selecting a back-extraction agent to back-extract the oil phase, wherein S3 includes:

[0105] The washed loaded organic phase (oil phase) was back-extracted with H2SO4 solution to obtain back-extraction residue and blank organic phase. The H2SO4 solution used as the back-extraction agent had a concentration of 2.0 mol / L, the back-extraction temperature was 25℃, the volume ratio of oil phase to H2SO4 solution during back-extraction was 1:1, the back-extraction time was 12 min, and the phase separation time was 4 min.

[0106] The blank organic phase obtained by back-extraction is recycled as an extraction solvent.

[0107] S4. Add NH4Cl, a precipitant, to the back-extraction residue. The concentration of the precipitant is 3.0 mol / L. The amount added is based on the molar ratio of NH4Cl to vanadium in the back-extraction residue of 1.5. After stirring evenly, let it stand to precipitate. After filtering and separating the precipitated solid phase, dry it to remove moisture. Then, introduce oxygen and calcine it at 550℃ for 2.5 h. After calcination, vanadium pentoxide with high purity can be obtained.

[0108] In this embodiment, the vanadium recovery rate in the acidic vanadium solution is 99.9%, and the purity of the vanadium pentoxide obtained after calcination is 99.7%.

[0109] Example 3

[0110] In this embodiment, the extraction solvent consists of extractant 2,6-dihydroxyanthraquinone, diluent 260# solvent oil, and modifier TBP, wherein the volume percentages of extractant 2,6-dihydroxyanthraquinone, diluent 260# solvent oil, and modifier TBP account for 25%, 70%, and 5% of the total volume percentage of the extractant, respectively.

[0111] The method in this embodiment includes the following steps:

[0112] S1. After roasting and acid leaching, vanadium slag is used to obtain acidic vanadium solution. S1 includes: S101. Preparation of acidic vanadium solution: After roasting, 1.0 mol / L H2SO4 and 1.5 mol / L NaOH are added to form a first solution, and the pH of the first solution is adjusted to 3.0.

[0113] S102. Add reducing agent Na2S to the first solution and stir for 5 min to obtain a solution mainly containing tetravalent vanadium and divalent iron, namely acidic vanadium solution, wherein the acidic vanadium solution contains 20 g / L of vanadium.

[0114] S2, extracting the acidic vanadium solution to obtain an oil phase and an aqueous phase, wherein S2 comprises:

[0115] S201. Mix the acidic vanadium solution with the extraction solvent and perform three-stage extraction to obtain a loaded organic phase (oil phase) and raffinate (aqueous phase), wherein the volume ratio of the oil phase to the aqueous phase is 1:1.

[0116] The extraction solvent is composed of 2,6-dihydroxyanthraquinone (extractant), 260# solvent oil (diluent), and TBP (modifier); wherein 2,6-dihydroxyanthraquinone accounts for 25% of the total volume of the extraction solvent, 260# solvent oil accounts for 70% of the total volume of the extraction solvent, and TBP (modifier) ​​accounts for 5% of the total volume of the extraction solvent; the extraction temperature is 30℃, the volume ratio of the extraction solvent to the acidic vanadium solution is 1:1, the extraction time is 12 min, and the phase separation time is 2 min;

[0117] S202. Wash the above-obtained supported organic phase (oil phase) with 0.5 mol / L H2SO4 solution. The volume ratio of the washing solution to the supported organic phase (oil phase) is 1:1. Under the condition of washing temperature of 25℃, wash twice. (During the phase separation process, some other ions are carried in the oil phase. Washing with 0.5 mol / L H2SO4 solution can ensure that the purity of vanadium recovered from the oil phase is high).

[0118] S3, Selecting a back-extraction agent to back-extract the oil phase, wherein S3 includes:

[0119] The washed loaded organic phase (oil phase) was back-extracted with HCl solution to obtain back-extraction residue and blank organic phase. The HCl solution used as the back-extraction agent had a concentration of 2.0 mol / L, the back-extraction temperature was 25℃, the volume ratio of the loaded organic phase (oil phase) to the HCl solution during back-extraction was 1:1, the back-extraction time was 8 min, and the phase separation time was 3 min.

[0120] The blank organic phase obtained by back-extraction is recycled as an extraction solvent.

[0121] Ammonium nitrate, a precipitant, is added to the back-extraction residue. The concentration of the precipitant is 3.0 mol / L, and the amount added is based on a molar ratio of ammonium nitrate to vanadium in the back-extraction residue of 1.5. After stirring evenly, the mixture is allowed to stand and precipitate. The precipitated solid phase is filtered and separated, then dried to remove moisture. Oxygen is then introduced, and the mixture is calcined at 550℃ for 2.5 h. After calcination, vanadium pentoxide with high purity can be obtained.

[0122] In this embodiment, the vanadium recovery rate in the acidic vanadium solution was 97.6%, and the purity of the vanadium pentoxide obtained after calcination was 99.8%.

[0123] Example 4

[0124] In this embodiment, the extraction solvent consists of extractant 2-tert-butylanthraquinone, diluent acetone oxime, methanol, and modifier TBP, wherein the volume percentages of extractant 2-tert-butylanthraquinone, diluent acetone oxime, methanol, and modifier TBP account for 35%, 60%, and 5% of the total volume percentage of the extractant, respectively.

[0125] The method in this embodiment includes the following steps:

[0126] S1. After roasting and acid leaching, vanadium slag is used to obtain acidic vanadium solution. S1 includes: S101. Preparation of acidic vanadium solution: After roasting, 2.0 mol / L H2SO4 and 2.5 mol / L NaOH are added to form a first solution, and the pH of the first solution is adjusted to 4.0.

[0127] S102. Add reducing agent Na2SO3 to the first solution, and then stir for 8 min to obtain a solution mainly containing tetravalent vanadium and divalent iron, i.e., acidic vanadium solution; the acidic vanadium solution contains 20 g / L of vanadium and 0.05 g / L of iron.

[0128] S2, extracting the acidic vanadium solution to obtain an oil phase and an aqueous phase, wherein S2 comprises:

[0129] S201. Mix the acidic vanadium solution with the extraction solvent and perform three-stage extraction to obtain a loaded organic phase (oil phase) and raffinate (aqueous phase), wherein the volume ratio of the oil phase to the aqueous phase is 1:1.

[0130] The extraction solvent is a mixture of 2-tert-butylanthraquinone (extractant), acetone oxime and methanol (diluent), and TBP (modifier); wherein 2-tert-butylanthraquinone accounts for 35% of the total volume of the extraction solvent, acetone oxime and methanol account for 60% of the total volume of the extraction solvent, and TBP accounts for 5% of the total volume of the extraction solvent; the extraction temperature is 25°C, the volume ratio of the extraction solvent to the acidic vanadium solution is 1:1, the extraction time is 8 min, and the phase separation time is 2 min;

[0131] S202. Wash the above-obtained supported organic phase (oil phase) with 0.5 mol / L H2SO4 solution. The volume ratio of the washing solution to the supported organic phase (oil phase) is 1:1. The washing temperature is 25℃. Perform one wash.

[0132] S3, Selecting a back-extraction agent to back-extract the oil phase, wherein S3 includes:

[0133] The washed loaded organic phase (oil phase) was back-extracted with oxalic acid solution to obtain back-extraction residue and blank organic phase. The concentration of oxalic acid solution used as the back-extraction agent was 2.5 mol / L, the back-extraction temperature was 25℃, the volume ratio of oil phase to oxalic acid solution was 1:2 during each back-extraction stage, the back-extraction time was 10 min, and the phase separation time was 3 min.

[0134] The blank organic phase obtained by back-extraction is recycled as an extraction solvent.

[0135] S4. Add ammonia water as a precipitant to the back-extraction residue. The concentration of the precipitant is 2.0 mol / L. The amount added is based on the molar ratio of ammonia water to vanadium in the back-extraction residue of 1.5. After stirring evenly, let it stand to precipitate. After filtering and separating the precipitated solid phase, dry it to remove moisture. Then, introduce oxygen and calcine it at 550℃ for 2.5 h. After calcination, vanadium pentoxide with high purity can be obtained.

[0136] In this embodiment, the vanadium recovery rate in the acidic vanadium solution was 99.5%, and the purity of the vanadium pentoxide obtained after calcination was 99.6%.

[0137] Example 5

[0138] In this embodiment, the extraction solvent consists of extractant P204+P507, diluent sulfonated kerosene, and modifier TBP, wherein the volume percentages of extractant P204+P507, diluent ethyl acetate, and modifier TBP account for 10%+20%, 65%, and 5% of the total volume percentage of the extractant, respectively.

[0139] The method in this embodiment includes the following steps:

[0140] S1. After roasting and acid leaching, vanadium slag is used to obtain acidic vanadium solution. S1 includes: S101. Preparation of acidic vanadium solution: After roasting, 1.0 mol / L NaOH and 1.0 mol / L H2SO4 are added to form a first solution, and the pH of the first solution is adjusted to 3.0.

[0141] S102. Add reducing agent Na2SO3 to the first solution, then stir for 8 min to obtain a solution mainly containing tetravalent vanadium and divalent iron, i.e., acidic vanadium solution, wherein the acidic vanadium solution contains 20 g / L of vanadium; S2. Extract the acidic vanadium solution to obtain an oil phase and an aqueous phase, wherein S2 includes:

[0142] S201. Acidic vanadium solution is mixed with an extraction solvent and subjected to two-stage extraction to obtain a loaded organic phase (oil phase) and raffinate (aqueous phase), wherein the volume ratio of the oil phase to the aqueous phase is 1:1; the extraction solvent is composed of extractant P204+P507, diluent ethyl acetate, and modifier TBP; wherein P204+P507 accounts for 30% of the total volume of the extraction solvent, sulfonated kerosene accounts for 65% of the total volume of the extraction solvent, and modifier TBP accounts for 5% of the total volume of the extraction solvent; wherein the extraction temperature is 25℃, the volume ratio of the extraction solvent to the acidic vanadium solution is 1:1, the extraction time is 8 min, and the phase separation time is 2 min;

[0143] S202. Wash the above-obtained supported organic phase (oil phase) with deionized water. The volume percentage of the washing solution to the supported organic phase (oil phase) is 1:1. The washing temperature is 25°C. Perform two washes.

[0144] S3, Selecting a back-extraction agent to back-extract the oil phase, wherein S3 includes:

[0145] S301. The washed loaded organic phase (oil phase) is back-extracted with (NH4)2CO3 solution to obtain back-extraction residue and blank organic phase; the concentration of (NH4)2CO3 solution used for back-extraction is 2.5 mol / L, the back-extraction temperature is 25℃, the volume ratio of loaded organic phase (oil phase) to (NH4)2CO3 solution during back-extraction is 1:1, the back-extraction time is 8 min, and the phase separation time is 3 min;

[0146] (In this embodiment, the volume ratio of oil phase to (NH4)2CO3 solution during back-extraction is between 0.5:1 and 2:1, which does not affect the extraction effect. In this embodiment, a volume ratio of oil phase to (NH4)2CO3 solution of 1:1 is selected for back-extraction.)

[0147] The blank organic phase obtained by back-extraction is recycled as an extraction solvent.

[0148] S4. Add NH4Cl, a precipitant, to the back-extraction residue. The concentration of the precipitant is 3.0 mol / L. The amount added is based on the molar ratio of NH4Cl to vanadium in the back-extraction residue of 1.5. After stirring evenly, let it stand to precipitate. After filtering and separating the precipitated solid phase, dry it to remove moisture. Then, introduce oxygen and calcine it at 550℃ for 2.5 h. After calcination, vanadium pentoxide with high purity can be obtained.

[0149] In this embodiment, the vanadium recovery rate in the acidic vanadium solution was 99.3%, and the purity of the vanadium pentoxide obtained after calcination was 99.5%.

[0150] Example 6

[0151] In this embodiment, the extraction solvent consists of extractant 1,5-dibromoanthracene-9,10-dione, diluent sulfonated kerosene, and modifier TBP, wherein the volume percentages of extractant 1,5-dibromoanthracene-9,10-dione, diluent sulfonated kerosene, and modifier TBP are 35%, 5%, and 60%, respectively.

[0152] The method in this embodiment includes the following steps:

[0153] S1. After roasting and acid leaching, vanadium slag is used to obtain acidic vanadium solution. S1 includes: S101. Preparation of acidic vanadium solution: After roasting, 2.5 mol / L H2SO4 and 2.5 mol / L NaOH are added to form a first solution, and the pH of the first solution is adjusted to 4.0.

[0154] S102. Add reducing agent Na2SO3 to the first solution, and then stir for 5 min to obtain a solution mainly containing tetravalent vanadium and divalent iron, i.e., acidic vanadium solution; the solution contains 20 g / L of vanadium.

[0155] S2, extracting the acidic vanadium solution to obtain an oil phase and an aqueous phase, wherein S2 comprises:

[0156] S201. Mix the acidic vanadium solution with the extraction solvent and perform three-stage extraction to obtain a loaded organic phase (oil phase) and raffinate (aqueous phase), wherein the volume ratio of the extraction solvent oil phase to the aqueous phase is 1:1.

[0157] The extraction solvent is a mixture of 1,5-dibromoanthracene-9,10-dione (extractant), sulfonated kerosene (diluent), and TBP (modifier); wherein 1,5-dibromoanthracene-9,10-dione accounts for 35% of the total volume of the extraction solvent, kerosene accounts for 60% of the total volume of the extraction solvent, and TBP accounts for 5% of the total volume of the extraction solvent; the extraction temperature is 25°C, the volume ratio of the extraction solvent to the acidic vanadium solution is 1:1, the extraction time is 8 min, and the phase separation time is 4 min;

[0158] S202. Wash the above-obtained supported organic phase (oil phase) with 0.5 mol / L H2SO4 solution. The volume ratio of washing solution to supported organic phase (oil phase) is 1:1. The washing temperature is 25℃. Perform one wash. (During the phase separation process, some other ions are carried in the oil phase. Washing with 0.5 mol / L H2SO4 solution can ensure that the purity of vanadium recovered from the oil phase is high.)

[0159] S3, Selecting a back-extraction agent to back-extract the oil phase, wherein S3 includes:

[0160] S301. The washed loaded organic phase is back-extracted with H2SO4 solution to obtain back-extraction residue and blank organic phase; the H2SO4 solution used for back-extraction has a concentration of 3.0 mol / L, the back-extraction temperature is 25℃, the volume ratio of the loaded organic phase (oil phase) to the H2SO4 solution during back-extraction is 1:1, the back-extraction time is 9 min, and the phase separation time is 2 min.

[0161] The blank organic phase obtained by back-extraction is recycled as an extraction solvent.

[0162] S4. Add precipitant (NH4)2CO3 to the back-extraction residue. The concentration of the precipitant is 2.5 mol / L. The amount added is based on the molar ratio of (NH4)2CO3 solution to vanadium in the back-extraction residue of 1.5. After stirring evenly, let it stand to precipitate. After filtering and separating the precipitated solid phase, dry it to remove moisture. Then, introduce oxygen and calcine it at 550℃ for 2.5 h. After calcination, vanadium pentoxide with high purity can be obtained.

[0163] In this embodiment, the vanadium recovery rate in the acidic vanadium solution was 97.8%, and the purity of the vanadium pentoxide obtained after calcination was 99.7%.

[0164] Example 7

[0165] In this embodiment, the extraction solvent consists of the extractant 1-hydroxyanthraquinone, the diluent kerosene, and the modifier TBP, wherein the volume percentages of the extractant 1-hydroxyanthraquinone, the diluent kerosene, and the modifier TBP are 20%, 5%, and 75%, respectively.

[0166] The method in this embodiment includes the following steps:

[0167] S1. After roasting and acid leaching, vanadium slag is used to obtain acidic vanadium solution. S1 includes: S101. Preparation of acidic vanadium solution: After roasting, 2.0 mol / L H2SO4 and 3.0 mol / L NaOH are added to form a first solution, and the pH of the first solution is adjusted to 5.0.

[0168] S102. Add reducing agent Na2SO3 to the first solution, and then stir for 4 min to obtain a solution mainly containing tetravalent vanadium and divalent iron, i.e., acidic vanadium solution; the acidic vanadium solution contains 20 g / L of vanadium;

[0169] S2, extracting the acidic vanadium solution to obtain an oil phase and an aqueous phase, wherein S2 comprises:

[0170] S201. Mix the acidic vanadium solution with the extraction solvent and perform four-stage extraction to obtain a loaded organic phase (oil phase) and raffinate (aqueous phase), wherein the volume ratio of the extraction solvent oil phase to the aqueous phase is 1:1.

[0171] The extraction solvent is a mixture of 1-hydroxyanthraquinone (extractant), kerosene (diluent), and TBP (modifier); wherein 1-hydroxyanthraquinone accounts for 20% of the total volume of the extraction solvent, kerosene accounts for 75% of the total volume of the extraction solvent, and TBP accounts for 5% of the total volume of the extraction solvent; wherein the extraction temperature is 30°C, the volume ratio of the extraction solvent to the acidic vanadium solution is 1:1, the extraction time is 7 min, and the phase separation time is 2 min;

[0172] S202. Wash the above-obtained supported organic phase (oil phase) with deionized water. The volume percentage of the washing liquid to the supported organic phase (oil phase) is 1:1. The washing temperature is 25°C. Perform two washes.

[0173] S3, Selecting a back-extraction agent to back-extract the oil phase, wherein S3 includes:

[0174] S301. The washed loaded organic phase is back-extracted with phosphoric acid solution to obtain back-extraction residue and blank organic phase; the concentration of phosphoric acid solution used as the back-extraction agent is 2.5 mol / L, the back-extraction temperature is 30℃, the volume ratio of oil phase to phosphoric acid solution during back-extraction is 1:1, the back-extraction time is 10 min, and the phase separation time is 3 min.

[0175] The blank organic phase obtained by back-extraction is recycled as an extraction solvent.

[0176] S4. Add NH4Cl precipitant to the back-extraction residue. The concentration of the precipitant is 3.0 mol / L. The amount added is based on the molar ratio of NH4Cl solution to vanadium in the back-extraction residue of 1.5. After stirring evenly, let it stand to precipitate. After filtering and separating the precipitated solid phase, dry it to remove moisture. Then, introduce oxygen and calcine it at 550℃ for 2.5 h. After calcination, vanadium pentoxide with high purity can be obtained.

[0177] In this embodiment, the vanadium recovery rate in the acidic vanadium solution was 98.8%, and the purity of the vanadium pentoxide obtained after calcination was 99.6%.

[0178] Comparative Example 1

[0179] In this embodiment, the extraction solvent consists of extractant cyclohexane, diluent sulfonated kerosene, and modifier TBP, wherein the volume percentages of extractant cyclohexane, diluent sulfonated kerosene, and modifier TBP are 40%, 5%, and 55%, respectively.

[0180] The method in this embodiment includes the following steps:

[0181] S1. After roasting and acid leaching, vanadium slag is used to obtain acidic vanadium solution. S1 includes: S101. Preparation of acidic vanadium solution: After roasting, 2.0 mol / L H2SO4 and 2.0 mol / L NaOH are added to form a first solution, and the pH of the first solution is adjusted to 3.0.

[0182] S102. Add reducing agent Na2SO3 to the first solution, and then stir for 6 min to obtain a solution mainly containing tetravalent vanadium and divalent iron, i.e., acidic vanadium solution, wherein the solution contains 20 g / L of vanadium.

[0183] S2, extracting the acidic vanadium solution to obtain an oil phase and an aqueous phase, wherein S2 comprises:

[0184] S201. Mix the acidic vanadium solution with the extraction solvent and perform four-stage extraction to obtain a loaded organic phase (oil phase) and raffinate (aqueous phase), wherein the volume ratio of the extraction solvent oil phase to the aqueous phase is 1:1.

[0185] The extraction solvent is a mixture of cyclohexane (extractant), sulfonated kerosene (diluent), and TBP (modifier); wherein cyclohexane accounts for 40% of the total volume of the extraction solvent, kerosene accounts for 55% of the total volume of the extraction solvent, and TBP accounts for 5% of the total volume of the extraction solvent; wherein the extraction temperature is 25°C, the volume ratio of the extraction solvent to the acidic vanadium solution is 1:1, the extraction time is 10 min, and the phase separation time is 4 min;

[0186] S202. Wash the above-obtained supported organic phase (oil phase) with 0.5 mol / L H2SO4 solution. The volume ratio of washing solution to supported organic phase (oil phase) is 1:1. The washing temperature is 25℃. Perform two washes. (During the phase separation process, some other ions are carried in the oil phase. Washing with 0.5 mol / L H2SO4 solution can ensure that the purity of vanadium recovered from the oil phase is high.)

[0187] S3, Selecting a back-extraction agent to back-extract the oil phase, wherein S3 includes:

[0188] S301. The washed loaded organic phase (oil phase) is back-extracted with H2SO4 solution to obtain back-extraction residue and blank organic phase; the H2SO4 solution used as the back-extraction agent has a concentration of 3.5 mol / L, the back-extraction temperature is 30℃, the volume ratio of the loaded organic phase (oil phase) to the H2SO4 solution during back-extraction is 1:1, the back-extraction time is 10 min, and the phase separation time is 2 min;

[0189] The blank organic phase obtained by back-extraction is recycled as an extraction solvent.

[0190] S4. Add precipitant (NH4)2CO3 to the back-extraction residue. The concentration of the precipitant is 2.5 mol / L. The amount added is based on the molar ratio of (NH4)2CO3 to vanadium in the back-extraction residue of 1.5. After stirring evenly, let it stand to precipitate. After filtering and separating the precipitated solid phase, dry it to remove moisture. Then, introduce oxygen and calcine it at 550℃ for 2.5 h. After calcination, vanadium pentoxide with high purity can be obtained.

[0191] In this embodiment, the vanadium recovery rate in the acidic vanadium solution was 85.8%, and the purity of the vanadium pentoxide obtained after calcination was 88.7%.

[0192] Comparative Example 2

[0193] In this embodiment, the extraction solvent consists of the extractant 3-hydroxy-2-butanone, the diluent acetone oxime, methanol, and the modifier TBP, wherein the volume percentages of the extractant 3-hydroxy-2-butanone, the diluent acetone oxime, and the methanol modifier TBP account for 50%, 45%, and 5% of the total volume percentage of the extractant, respectively.

[0194] The method in this embodiment includes the following steps:

[0195] S1. After roasting and acid leaching, vanadium slag is used to obtain acidic vanadium solution. S1 includes: S101. Preparation of acidic vanadium solution: After roasting, 3.0 mol / L H2SO4 and 2.5 mol / L NaOH are added to form a first solution, and the pH of the first solution is adjusted to 3.5.

[0196] S102. Add reducing agent Na2SO3 to the first solution, and then stir for 10 min to obtain a solution mainly containing tetravalent vanadium and divalent iron, i.e., acidic vanadium solution; the acidic vanadium solution contains 20 g / L of vanadium.

[0197] S2, extracting the acidic vanadium solution to obtain an oil phase and an aqueous phase, wherein S2 comprises:

[0198] S201. Mix the acidic vanadium solution with the extraction solvent and perform 5-stage extraction to obtain a loaded organic phase (oil phase) and raffinate (aqueous phase), wherein the volume ratio of the extraction solvent oil phase to the aqueous phase is 1:1.

[0199] The extraction solvent is a mixture of 3-hydroxy-2-butanone (extractant), acetone oxime and methanol (diluent), and TBP (modifier); wherein 3-hydroxy-2-butanone accounts for 50% of the total volume of the extraction solvent, acetone oxime and methanol (diluent) account for 45% of the total volume of the extraction solvent, and TBP (modifier) ​​accounts for 5% of the total volume of the extraction solvent; the extraction temperature is 25°C, the volume ratio of the extraction solvent to the acidic vanadium solution is 1:1, the extraction time is 10 min, and the phase separation time is 3 min;

[0200] S202. Wash the above-obtained supported organic phase (oil phase) with 0.5 mol / L H2SO4 solution. The volume ratio of washing solution to supported organic phase (oil phase) is 1:1. The washing temperature is 25℃. Perform two washes. (During the phase separation process, some other ions are carried in the oil phase. Washing with 0.5 mol / L H2SO4 solution can ensure that the purity of vanadium recovered from the oil phase is high.)

[0201] S3, Selecting a back-extraction agent to back-extract the oil phase, wherein S3 includes:

[0202] The washed loaded organic phase (oil phase) was back-extracted with H2SO4 solution to obtain back-extraction residue and blank organic phase. The back-extraction agent used was oxalic acid solution with a concentration of 3.0 mol / L. The back-extraction temperature was 25℃. The volume ratio of the loaded organic phase (oil phase) to the oxalic acid solution during back-extraction was 1:2. The back-extraction time was 12 min and the phase separation time was 5 min.

[0203] The blank organic phase obtained by back-extraction is recycled as an extraction solvent.

[0204] S4. Add ammonia water as a precipitant to the back-extraction residue. The concentration of the precipitant is 3.0 mol / L. The amount added is 1.5 according to the molar ratio of vanadium in the ammonia water back-extraction residue. After stirring evenly, let it stand to precipitate. After filtering and separating the precipitated solid phase, dry it to remove moisture. Then, introduce oxygen and calcine it at 550℃ for 2.5 h. After calcination, vanadium pentoxide with high purity can be obtained.

[0205] In this embodiment, the vanadium recovery rate in the acidic vanadium solution was 85.1%, and the purity of the vanadium pentoxide obtained after calcination was 90.6%.

[0206] A comparison of the examples and comparative examples revealed that the vanadium recovery rate in the acidic vanadium solution in Examples 1-6 was over 97%, and the purity of the vanadium pentoxide obtained after calcination was over 99%. In contrast, the vanadium recovery rate in the acidic vanadium solution in the comparative examples was below 86%, and the purity of the vanadium pentoxide obtained after calcination was below 90%. This indicates that a suitable extractant can increase the vanadium recovery rate and the purity of the vanadium pentoxide obtained after calcination of the back-extraction residue.

[0207] The various embodiments of the present invention have now been described in detail. While some specific embodiments of the invention have been described in detail by way of examples, those skilled in the art should understand that the above examples are for illustrative purposes only and not for limiting the scope of the invention. Those skilled in the art should understand that modifications can be made to the above embodiments or equivalent substitutions can be made to some technical features without departing from the scope and spirit of the invention. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any manner.

Claims

1. A method for separating cations from acidic vanadium solution, characterized in that, Includes the following steps: S1. Vanadium slag is roasted and then acid-leached to obtain acidic vanadium solution. S2. An extraction solvent is selected to extract the acidic vanadium solution, yielding an oil phase and an aqueous phase; S3. Select a back-extraction agent to back-extract the oil phase, obtain back-extraction residue and blank organic phase, and collect the back-extraction residue; S4. The precipitate and back-extracted residue is dried and calcined to obtain vanadium pentoxide; The extraction solvent includes: an extractant, a diluent, and a modifier; The extractant comprises one or more of anthraquinones and their derivatives and 1,4-anthraquinones and their derivatives.

2. The method for separating cations from acidic vanadium solution according to claim 1, characterized in that, The anthraquinones and their derivatives include structures of the following formula (I): （I）； R1 to R8 are independently selected from H and C1 to C. 16 Alkyl groups, -OH groups, -X groups; X is selected from F, Cl, or Br; The 1,4-anthradinone and its derivatives comprise the structure of formula (II): (II); Among them, R9~R 16 Independently selected from H, C1~C 16 Alkyl groups, -OH groups, -X groups; X is selected from F, Cl, or Br.

3. The method for cation separation in acidic vanadium solution according to claim 1, characterized in that, The extractant comprises one or more of the following: 9,10-anthraquinone, 1,4-anthradinone, 2-methylanthraquinone, 2,6-dihydroxyanthraquinone, 1-hydroxyanthraquinone, 2-tert-butylanthraquinone, and 1,5-dibromoanthra-9,10-dione.

4. The method for separating cations from acidic vanadium solution according to claim 1, characterized in that, The modifier includes: tributyl phosphate.

5. The method for separating cations from acidic vanadium solution according to claim 1, characterized in that, The diluent includes one or more of the following: kerosene, sulfonated kerosene, 260# solvent oil, acetone oxime, methanol, and ethyl acetate.

6. The method for separating cations from acidic vanadium solution according to claim 2, characterized in that, The stripping agent includes one or more of the following: sulfuric acid, hydrochloric acid, nitric acid, phosphoric acid, oxalic acid, ethanol, ammonium carbonate, ammonium chloride, and ammonium nitrate.

7. The method for cation separation in acidic vanadium solution according to claim 2, characterized in that, During extraction, the amount of extraction solvent is controlled at 10% to 50% of the oil phase volume, the volume ratio of oil phase to water phase is controlled at (0.5:1) to (2:1), the pH of the system is controlled at 1.0 to 2.5, the time is controlled at 8 to 10 min, and the temperature is controlled at 15 to 30℃.

8. The method for cation separation in acidic vanadium solution according to claim 4, characterized in that, The concentration of the stripping agent is in the range of 0.5~5.0 mol / L, the volume ratio of the blank organic phase to the stripping agent is controlled at (0.5:1)~(2:1), the time is controlled at 8~10 min, and the temperature is controlled at 15~30℃.

9. The method for separating cations from acidic vanadium solution according to claim 4, characterized in that, The acidic vanadium solution in S1 also undergoes a filtration step and / or a settling step. The filtration step includes filtration after adding flocculant or direct filtration. The filtration step uses a precision filter, a centrifugal filter, or a membrane filter. The settling time in the settling step is ≥6 hours.

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