Vanadium liquid extractant and use thereof

Abstract

A vanadium liquid extractant and the use thereof. Raw materials for preparing the vanadium liquid extractant at least comprise the following components: organic phosphate, organic amine, and a diluent, the mass ratio of the organic phosphate, the organic amine, and the diluent being (2-4): (1-5): (5-10). By optimizing a vanadium liquid extractant formulation system, the number of extraction stages of tetravalent vanadium ions in a vanadium-containing feed liquid is reduced, and 99.5% or more impurities in the vanadium-containing feed liquid can be isolated without additionally adding an impurity removing agent or sodium hydroxide, providing a low-cost and simple-process preparation method for a vanadium electrolyte.

Description

A vanadium liquid extractant and its application Technical Field

[0001] This invention relates to the field of C22B34 / 22 technology, specifically to a vanadium liquid extractant and its application. Background Technology

[0002] Currently, the method for preparing vanadium electrolytes involves using ammonium metavanadate or vanadium pentoxide to produce high-purity vanadium pentoxide, which is then used to prepare the electrolyte through low-temperature dissolution-reduction, electrolysis, and high-temperature reduction-dissolution. However, the overall process is complex and costly. Chinese patent (publication number CN115441029A) discloses a vanadium electrolyte and its preparation method and application, but this requires the addition of multiple impurity removal agents before reduction extraction, resulting in a complex and costly process. Therefore, there is an urgent need to develop a low-cost, simple method for preparing vanadium electrolytes. Purification optimization of vanadium-containing solutions is one effective approach. Vanadium-containing solutions are typically purified using an extraction-back-extraction process, but current purification processes based on different extraction mechanisms still suffer from low extraction efficiency, complex processes, high costs, and high levels of waste. Chinese patent (authorization announcement number CN113604685B) discloses a method for preparing vanadium oxide from a vanadium-containing solution. It first adjusts the pH value with sodium hydroxide, then adds a kerosene solution of P204 or P507 as an extractant for extraction, and finally uses sulfuric acid as a back-extraction agent for back-extraction. The aim is to solve the problems of low impurity removal rate and long process. However, this purification method requires continuous consumption of sodium hydroxide and generates sodium sulfate, resulting in high costs and high levels of waste, making it unsuitable for large-scale industrial application. Chinese patent (CN 114959251 B) discloses a vanadium slag roasting and leaching method that uses P204 at an O / A (extraction ratio: organic phase volume / aqueous phase volume) of 1:5 for five extraction stages, resulting in multiple extraction stages and low extraction efficiency. Summary of the Invention

[0003] To address the aforementioned issues, this invention provides a vanadium solution extractant. By optimizing the vanadium solution extractant formulation system, the number of extraction stages for tetravalent vanadium ions in vanadium-containing solutions is significantly reduced. It can isolate over 99.5% of impurities in vanadium-containing solutions without the need for additional impurity removers or sodium hydroxide, thus providing a low-cost and simple preparation method for vanadium electrolytes.

[0004] The present invention provides a vanadium liquid extractant, the raw materials for which include at least the following components: organic phosphate ester, organic amine, and diluent, wherein the mass ratio of the organic phosphate ester, organic amine, and diluent is (2-4):(1-5):(5-10).

[0005] As a preferred technical solution, the organophosphate is selected from at least one of P507, P204, and Cyanex272, preferably P507 or P204.

[0006] As a preferred technical solution, the organic amine includes at least aliphatic tertiary amines.

[0007] As a preferred technical solution, the aliphatic tertiary amine has the structural formula N-R3, where R is C5-C6. 10 Straight-chain alkyl groups.

[0008] As a preferred technical solution, the aliphatic tertiary amine is tri-n-octylamine (TOA, CAS No. 1116-76-3) or trioctyldecyl tertiary amine (CAS No. 68814-95-9).

[0009] As a preferred technical solution, the diluent is selected from at least one of sulfonated kerosene, petroleum ether, toluene, n-octanol, benzene, chloroform, and 2-ethylhexanol, preferably sulfonated kerosene.

[0010] As a preferred technical solution, the mass ratio of the organic phosphate ester, organic amine, and diluent is 3:(1-5):7, preferably 3:(3-5):7.

[0011] The vanadium extractant provided by this invention, by compounding P507 or P204 with aliphatic tertiary amines in a certain ratio and then diluting it to a specific concentration with sulfonated kerosene, effectively overcomes the problems of low extraction efficiency, complex process flow, high cost, and high levels of waste in existing processes, and is easy to promote and apply on a large scale industrial basis. In particular, the vanadium extractant compounded with P507 or P204, tri-n-octylamine, and sulfonated kerosene in a mass ratio of 3:(3-5):7 effectively isolates 1-5 wt% of tetravalent vanadium ions in vanadium-containing solutions from impurities such as sodium, magnesium, silicon, and calcium, achieving an extraction rate of ≥99.0% after 2-3 consecutive extractions.

[0012] Another aspect of the present invention provides an application of a vanadium solution extractant, used for the extraction of tetravalent vanadium ions from a vanadium-containing solution. The extraction method for tetravalent vanadium ions from the vanadium-containing solution includes at least the following steps:

[0013] (1) Extraction: Add vanadium extractant to vanadium-containing liquid and extract continuously 2-10 times to obtain the extract phase;

[0014] (2) Back-extraction: The extractant phase is back-extracted with sulfuric acid aqueous solution to obtain a high-purity tetravalent vanadium ion solution.

[0015] As a preferred technical solution, the volume ratio of the vanadium-containing liquid to the vanadium extractant is (0.5-2):1, preferably 1:1.

[0016] As a preferred technical solution, the concentration of the sulfuric acid aqueous solution is 1.5-3 mol / L, and the temperature of the back-extraction is 50-70℃.

[0017] As a preferred technical solution, the concentration of tetravalent vanadium ions in the vanadium-containing liquid is 1-5 wt%.

[0018] As a preferred technical solution, the vanadium-containing liquid also includes sodium ions, magnesium ions, silicon ions, and calcium ions.

[0019] As a preferred technical solution, the concentration of tetravalent vanadium ions in the vanadium-containing liquid is 1.8 wt%, the concentration of sodium ions is 43722.74 mg / L, the concentration of magnesium ions is 1374.74 mg / L, the concentration of silicon ions is 975.4 mg / L, the concentration of calcium ions is 712.16 mg / L, and the balance is water.

[0020] The vanadium liquid extractant provided by this invention can be reused repeatedly, and it can maintain a high extraction efficiency during reuse. The extraction rate remains above 99.5% after multiple reuses, which is highly economical.

[0021] By using the vanadium extractant provided by this invention to perform an extraction-back-extraction process on vanadium-containing liquid, a high-purity tetravalent vanadium ion solution can be obtained. After evaporating and concentrating the high-purity tetravalent vanadium ion solution and then performing charging electrolysis, a vanadium electrolyte product can be prepared. Beneficial effects

[0022] 1. This invention provides a vanadium solution extractant. By optimizing the formulation system of the vanadium solution extractant, the number of extraction stages of tetravalent vanadium ions in the vanadium-containing solution is greatly reduced. It can isolate more than 99.5% of impurities in the vanadium-containing solution without the need to add additional impurity removers or sodium hydroxide, providing a low-cost and simple preparation method for vanadium electrolyte.

[0023] 2. The vanadium liquid extractant provided by the present invention, by compounding P507 or P204 with fatty tertiary amines in a certain ratio and then diluting it with sulfonated kerosene to a specific concentration, effectively overcomes the problems of low extraction efficiency, complex process flow, high cost and high waste in the existing process, and is easy to realize large-scale industrial promotion and application.

[0024] 3. The present invention uses a vanadium extractant composed of P507 or P204, tri-octylamine, and sulfonated kerosene in a mass ratio of 3:(3-5):7. This extractant effectively isolates 1-5 wt% of tetravalent vanadium ions in the vanadium-containing liquid from impurities such as sodium, magnesium, silicon, and calcium. An extraction rate of ≥99.0% can be achieved by continuous extraction 2-3 times.

[0025] 4. The vanadium liquid extractant provided by the present invention can be reused repeatedly, and the vanadium liquid extractant can maintain a high extraction efficiency during the reuse process. The extraction rate is still above 99.5% after multiple reuses, which has extremely high economic efficiency.

[0026] 5. By using the vanadium extractant provided by this invention to perform an extraction-back-extraction process on vanadium-containing liquid, a high-purity tetravalent vanadium ion solution can be obtained. After evaporating and concentrating the high-purity tetravalent vanadium ion solution and then performing charging electrolysis, vanadium electrolyte products can be prepared. Detailed Implementation

[0027] Example 1

[0028] Example 1 of the present invention provides a vanadium liquid extractant, the raw materials for which include the following components: organic phosphate ester, organic amine, and diluent, wherein the mass ratio of organic phosphate ester, organic amine, and diluent is 3:3:7.

[0029] The organic phosphate ester is P507.

[0030] The organic amine is tri-n-octylamine (TOA, CAS number 1116-76-3).

[0031] The diluent is sulfonated kerosene (260#).

[0032] Example 1 of the present invention provides a method for extracting tetravalent vanadium ions from a vanadium-containing solution, comprising the following steps:

[0033] (1) Extraction: Add vanadium extractant to 200 mL of vanadium-containing liquid and extract three times continuously at 25±5℃. The extraction rate of the first extraction was 73.6%, the total extraction rate of the second extraction was 98.6%, and the total extraction rate after three extractions was 99.5%. The content of tetravalent vanadium ions in the raffinate after three extractions was 0.016 wt%, and the extract phase was obtained.

[0034] (2) Back-extraction: The extract phase was back-extracted with sulfuric acid aqueous solution. The back-extraction rate was 99.5%. The concentration of sodium ions, magnesium ions, silicon ions and calcium ions in the back-extraction solution (high-purity tetravalent vanadium ion solution) was 15.12 mg / L, 2.42 mg / L, 1.71 mg / L and 3.45 g / L. The impurities in the vanadium-containing solution were isolated by extraction-back-extraction at a rate of over 99.5%.

[0035] The vanadium-containing liquid contains 1.8 wt% tetravalent vanadium ions, 43722.74 mg / L sodium ions, 1374.74 mg / L magnesium ions, 975.4 mg / L silicon ions, and 712.16 mg / L calcium ions, with the remainder being water.

[0036] The volume ratio of the vanadium-containing liquid to the vanadium extractant is 1:1.

[0037] The concentration of the sulfuric acid aqueous solution is 2 mol / L, and the temperature of the back-extraction is 60°C.

[0038] Example 2

[0039] Example 2 of the present invention provides a vanadium extractant, the specific implementation of which is the same as that of Example 1, except that the mass ratio of the organic phosphate ester, organic amine, and diluent is 3:5:7. The extraction method for tetravalent vanadium ions from the vanadium-containing solution includes the following steps:

[0040] (1) Extraction: Add vanadium extractant to 200 mL of vanadium-containing liquid and extract twice at 25±5℃. The first extraction rate was 84.2% and the second total extraction rate was 99.0%. The content of tetravalent vanadium ions in the raffinate after the two extractions was 0.053 wt%, and the extract phase was obtained.

[0041] (2) Back-extraction: The extract phase was back-extracted with sulfuric acid aqueous solution. The back-extraction rate was 99.5%. The concentrations of impurities in the back-extraction solution were 11.24 mg / L, 1.94 mg / L, 1.83 mg / L, and 3.45 mg / L. The impurities in the vanadium-containing solution were isolated by extraction-back-extraction at a rate of over 99.5%.

[0042] Example 3

[0043] Example 3 of the present invention provides a vanadium extractant, the specific implementation of which is the same as that of Example 1, except that the mass ratio of the organic phosphate ester, organic amine, and diluent is 3:1:7. The extraction method for tetravalent vanadium ions from the vanadium-containing solution includes the following steps:

[0044] (1) Extraction: Add vanadium extractant to 200 mL of vanadium-containing liquid and extract 6 times continuously at 25±5℃. The extraction rate of the first extraction is 28.8%, the total extraction rate of the second extraction is 46.6%, and the total extraction rate after 6 extractions is 99.2%. The content of tetravalent vanadium ions in the raffinate after 6 extractions is 0.046 wt%, and the extract phase is obtained.

[0045] (2) Back-extraction: The extract phase was back-extracted with sulfuric acid aqueous solution. The back-extraction rate was 99.5%. The concentrations of impurities in the back-extraction solution were 21.24 mg / L, 2.56 mg / L, 1.66 mg / L, and 2.93 mg / L. The impurities in the vanadium-containing solution were isolated by extraction-back-extraction at a rate of over 99.5%.

[0046] Example 4

[0047] Example 4 of the present invention provides a vanadium extractant, the specific implementation of which is the same as that of Example 1, except that P507 is replaced by P204. The extraction method for tetravalent vanadium ions in the vanadium-containing solution includes the following steps:

[0048] (1) Extraction: Add vanadium extractant to 200 mL of vanadium-containing liquid and extract three times continuously at 25±5℃. The extraction rate of the first extraction was 72.8%, the total extraction rate of the second extraction was 97.5%, and the total extraction rate after three extractions was 99.4%. The content of tetravalent vanadium ions in the raffinate after three extractions was 0.023 wt%, and the extract phase was obtained.

[0049] (2) Back-extraction: The extract phase was back-extracted with sulfuric acid aqueous solution. The back-extraction rate was 99.5%. The concentrations of impurities in the back-extraction solution were 16.47 mg / L, 2.21 mg / L, 1.44 mg / L, and 2.36 mg / L. The impurities in the vanadium-containing solution were isolated by extraction-back-extraction at a rate of over 99.5%.

[0050] Example 5

[0051] Example 5 of the present invention provides a vanadium liquid extractant, the specific implementation of which is the same as that of Example 1, except that the extraction method for tetravalent vanadium ions in the vanadium-containing liquid includes the following steps:

[0052] (1) Extraction: Add vanadium extractant to 100 mL (108.1 g) of vanadium-containing solution and extract three times consecutively at 25±5℃. After the first extraction, 101.7 g of raffinate (containing 0.5456 wt% tetravalent vanadium ions) was obtained, with an extraction rate of 72.4%. After the second extraction, 95.6 g of raffinate (containing 0.0545 wt% tetravalent vanadium ions) was obtained, with a total extraction rate of 97.4%. After a total of three extractions, 92.5 g of raffinate (containing 0.01165 wt% tetravalent vanadium ions) was obtained, with a total extraction rate of 99.3%, and the extract phase was obtained.

[0053] (2) Back-extraction: The extract phase was back-extracted four times with sulfuric acid aqueous solution (125 mL each time), with a back-extraction rate of 99.5%, yielding a total of 570 g of back-extraction solution. The content of tetravalent vanadium ions in the back-extraction solution was 0.3357 wt%, the purity of sulfuric acid oxyvanadium was 99.986%, and the back-extraction rate was 99.5%. The concentrations of impurities in the back-extraction solution were 15.36 mg / L for sodium ions, 2.46 mg / L for magnesium ions, 1.65 mg / L for silicon ions, and 2.33 mg / L for calcium ions. The impurities in the vanadium-containing solution were isolated at a rate of over 99.5% after extraction-back-extraction.

[0054] (3) The back-extraction extractant phase is reused. The back-extraction extractant phase is used to extract the vanadium-containing liquid. The extraction phase O / A = 1. After three consecutive extractions, the vanadium content in the raffinate is detected and the total extraction rate is calculated. Then, the back-extraction phase is back-extracted with 2 mol / L sulfuric acid solution. The back-extraction extractant phase is used to extract the vanadium-containing liquid again. The vanadium extractant is used repeatedly for eight times. The total extraction rate after three consecutive extractions is calculated. The results are shown in Table 1.

[0055] Table 1

[0056] Data analysis shows that the extraction efficiency is advanced when the extractant is reused. The quality of the raffinate remains almost unchanged after eight cycles, meaning that TOA is not consumed during the process (unlike traditional NaOH, which is continuously consumed), and the extraction rate remains above 99.5% after multiple extractions.

[0057] Example 6

[0058] Example 6 of the present invention provides a vanadium liquid extractant and its application, comprising the following steps:

[0059] (1) Multi-stage countercurrent extraction: Vanadium-containing feed solution (same as in Example 1) and vanadium extractant (same as in Example 1) are processed in a 1:1 ratio through a three-stage countercurrent extraction device. After the two phases are balanced, the raffinate contains 0.015845 wt% vanadium and the vanadium-loaded extractant contains 2.1956 wt% vanadium.

[0060] (2) Multi-stage countercurrent extraction: 1.5 mol / L sulfuric acid aqueous solution and a 4-stage countercurrent extraction device are used to extract the vanadium-loaded extractant phase. The back-extraction temperature is 60℃, with a phase O / A ratio of 2. After the two phases are in equilibrium, an extractant with a vanadium content of 0.0243% (recycled) and a vanadium oxysulfate aqueous solution with a vanadium content of 3.8425 wt% (high-purity tetravalent vanadium ion solution) are obtained.

[0061] (3) Concentration: The vanadium oxysulfate solution with a vanadium content of 3.8425 wt% was dehydrated by vacuum distillation, and then the residual extractant was adsorbed by activated carbon. The sample was sent for testing to obtain a qualified vanadium electrolyte product.

[0062] Comparative Example 1

[0063] Comparative Example 1 of the present invention provides a vanadium extractant, the specific implementation of which is the same as that of Example 1, except that its preparation raw materials include the following components: an organic phosphate ester and a diluent, wherein the mass ratio of the organic phosphate ester to the diluent is 3:7. The extraction method for tetravalent vanadium ions in the vanadium-containing solution includes the following steps:

[0064] (1) Extraction: Add vanadium extractant to 200 mL of vanadium-containing liquid and extract 8 times continuously at 25±5℃. The extraction rate of the first extraction is 25.1%, the total extraction rate of the second extraction is 30.1%, and the total extraction rate after 8 extractions is 57%. The content of tetravalent vanadium ions in the raffinate after 8 extractions is 0.9474 wt%, and the extract phase is obtained. No subsequent back-extraction step is performed.

[0065] Comparative Example 2

[0066] Comparative Example 2 of the present invention provides a vanadium extractant, the specific implementation of which is the same as that of Example 1, except that its preparation raw materials include the following components: an organic phosphate ester and a diluent, wherein the mass ratio of the organic phosphate ester to the diluent is 3:7. The extraction method for tetravalent vanadium ions from the vanadium-containing solution includes the following steps:

[0067] (1) Extraction: A 30% sodium hydroxide aqueous solution was added to the vanadium extractant for saponification, and then used for extraction of 200 mL of vanadium-containing solution. The extraction was carried out 8 times at 25±5℃. The extraction rate was 45.1% in the first extraction and 60% in the second extraction. The total extraction rate after 8 extractions was 77.2%. The content of tetravalent vanadium ions in the raffinate after 8 extractions was 0.4940 wt%. The extract phase was obtained, and no subsequent back-extraction step was performed.

[0068] Comparative Example 3

[0069] Comparative Example 3 of the present invention provides a vanadium extractant, the specific implementation of which is the same as that of Example 1, except that TOA is replaced by TBP. The extraction method for tetravalent vanadium ions in the vanadium-containing solution includes the following steps:

[0070] (1) Extraction: Add vanadium extractant to 200 mL of vanadium-containing solution and extract 8 times continuously at 25±5℃. The extraction rate of the first extraction is 25.1%, the total extraction rate of the second extraction is 30.4%, and the total extraction rate after 8 extractions is 73.1%. The content of tetravalent vanadium ions in the raffinate after 8 extractions is 0.4837 wt%, and the extract phase is obtained. No subsequent back-extraction step is performed.

[0071] Comparative Example 4

[0072] Comparative Example 4 of the present invention provides a vanadium extractant, the specific implementation of which is the same as that of Example 1, except that its preparation raw materials include the following components: organic phosphate ester and organic amine, wherein the mass ratio of organic phosphate ester to organic amine is 5:5. The extraction method for tetravalent vanadium ions in the vanadium-containing solution includes the following steps:

[0073] (1) Extraction: Add vanadium extractant to 200mL of vanadium-containing liquid. During the extraction process at 25±5℃, a black viscous material appears, which cannot be effectively extracted. No subsequent back-extraction step is performed.

[0074] Comparative Example 5

[0075] Comparative Example 5 of the present invention provides a vanadium extractant, the specific implementation of which is the same as that of Example 1, except that the mass ratio of the organic phosphate ester, organic amine, and diluent is 6:1:14. The extraction method for tetravalent vanadium ions from the vanadium-containing solution includes the following steps:

[0076] (1) Extraction: Add vanadium extractant to 200 mL of vanadium-containing solution and extract 8 times continuously at 25±5℃. The extraction rate of the first extraction is 21.2%, the total extraction rate of the second extraction is 36.4%, and the total extraction rate after 8 extractions is 92.1%. The content of tetravalent vanadium ions in the raffinate after 8 extractions is 0.1427 wt%, and the extract phase is obtained. No subsequent back-extraction step is performed.

[0077] Comparative Example 6

[0078] Comparative Example 6 of the present invention provides a vanadium extractant, the specific implementation of which is the same as that of Example 1, except that the organic amine is replaced with dodecyl alcohol. The mass ratio of the organic phosphate ester, dodecyl alcohol, and diluent is 3:1:6. The extraction method of tetravalent vanadium ions in the vanadium-containing solution includes the following steps:

[0079] (1) Extraction: Add vanadium extractant to 200 mL of vanadium-containing liquid and extract at 25±5℃. After the first extraction, the content of tetravalent vanadium ions in the raffinate is 1.1407 wt%, and the extraction rate is 22%. The total extraction rate of the second extraction is 31.3%. The extraction rate of a single batch is too low, so no further extraction is performed.

[0080] Comparative Example 7

[0081] Comparative Example 7 of the present invention provides a vanadium liquid extractant, the specific implementation of which is the same as that of Example 1, except that the organic amine is replaced with isobutyl ketone. The mass ratio of the organic phosphate ester, isobutyl ketone, and diluent is 3:1:6. The extraction method of tetravalent vanadium ions in the vanadium-containing liquid includes the following steps: (1) Extraction: Add vanadium liquid extractant to 200 mL of vanadium-containing liquid and extract at 25±5℃. After the first extraction, the tetravalent vanadium ion content in the raffinate is 1.1462 wt%, and the extraction rate is 23.3%. The total extraction rate of the second extraction is 30.6%. The single batch extraction rate is too low, so no further extraction is performed.

Claims

1. A vanadium liquid extractant, characterized in that, The raw materials for its preparation include at least the following components: organic phosphate ester, organic amine, and diluent, wherein the mass ratio of the organic phosphate ester, organic amine, and diluent is (2-4):(1-5):(5-10).

2. The vanadium extractant according to claim 1, characterized in that, The organophosphate is selected from at least one of P507, P204, and Cyanex272.

3. The vanadium extractant according to claim 2, characterized in that, The organic amines include at least aliphatic tertiary amines.

4. The vanadium extractant according to claim 3, characterized in that, The structural formula of the fatty tertiary amine is N-R3, where R is C5-C6. 10 Straight-chain alkyl groups.

5. The vanadium extractant according to claim 4, characterized in that, The diluent is selected from at least one of sulfonated kerosene, petroleum ether, toluene, n-octanol, benzene, chloroform, and 2-ethylhexanol.

6. The vanadium extractant according to claim 5, characterized in that, The mass ratio of the organic phosphate ester, organic amine, and diluent is 3:(1-5):

7.

7. The application of a vanadium extractant according to any one of claims 1-6, characterized in that, It is used for the extraction of tetravalent vanadium ions from vanadium-containing solutions.

8. The application of the vanadium extractant according to claim 7, characterized in that, The extraction method for tetravalent vanadium ions from the vanadium-containing solution includes at least the following steps: (1) Extraction: Add vanadium extractant to vanadium-containing liquid and extract continuously 2-10 times to obtain the extract phase; (2) Back-extraction: The extractant phase is back-extracted with sulfuric acid aqueous solution to obtain a high-purity tetravalent vanadium ion solution.

9. The application of the vanadium extractant according to claim 8, characterized in that, The volume ratio of the vanadium-containing liquid to the vanadium extractant is (0.5-2):

1.

10. The application of the vanadium extractant according to claim 9, characterized in that, The high-purity tetravalent vanadium ion solution is used in the preparation of vanadium electrolyte products.

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