Extraction and separation of vanadium from vanadium-arsenic solution using hydrophobic subeutectic solvents

Abstract

This application discloses a method for extracting and separating vanadium from a vanadium-arsenic solution using a hydrophobic low eutectic solvent, which belongs to the field of nonferrous metallurgy. The method includes a step S100 of preparing a hydrophobic low eutectic solvent in which a hydrogen bond acceptor and a hydrogen bond donor are mixed and reacted to form a hydrogen bond network, and a step S200 of extracting and separating vanadium by mixing the hydrophobic low eutectic solvent with the vanadium-arsenic solution, vibrating, allowing the mixture to stand for phase separation, and then stripping the vanadium after phase separation. The hydrogen bond acceptor includes tetrabutylammonium chloride or tetrabutylammonium bromide, and the hydrogen bond donor includes n-octanol, n-nonanol, or n-decanol. The method of the present invention can be applied to accurately separate vanadium from impurities such as arsenic and tungsten in vanadium crystals. In the process of extracting and separating vanadium and arsenic using the aforementioned hydrophobic low eutectic solvent, there is no need to deliberately adjust the pH value of the solution. The operation is simple, economical, and safe, and the safety risks in the extraction process can be greatly reduced. This shows good prospects for the extraction and separation of vanadium and arsenic.

Description

[Technical Field]

[0001] The present invention relates to the technical field of nonferrous metallurgy, and in particular to a method for extracting and separating vanadium from a vanadium-arsenic solution using a hydrophobic low eutectic solvent. [Background technology]

[0002] In coal-fired power plants, the denitrification activity of SCR catalysts gradually declines with increasing operating time due to poisoning and aging of active components. Currently, spent SCR catalysts are typically processed using an alkaline leaching-stepwise precipitation process to separate elements such as vanadium, arsenic, silicon, and phosphorus from the TiO2 support. The elements are then separated in stages based on their different solubilities under different temperatures and alkaline concentrations. Patent application number CN202110213239.7 discloses a method for separating vanadium, tungsten, and arsenic from sodium hydroxide waste and its application. In this method, the sodium hydroxide waste is evaporated and concentrated, followed by a cooling crystallization process to crystallize vanadate, tungstate, and arsenate ions, resulting in alkali-treated crystals (i.e., vanadium crystals). The vanadium crystals are then dissolved, and the sodium hydroxide concentration is adjusted to perform two causticization reactions, allowing each element to be gradually precipitated based on its different solubility under different alkaline concentrations. In this method, after obtaining vanadium crystals, multiple caustic reactions must be carried out to separate vanadium, tungsten, and arsenic, which makes the operation procedure complicated and requires repeated adjustments of the alkalinity of the solution, thereby increasing production costs.

[0003] Extraction is a common method for separating similar ions or ionic groups. However, traditional extraction methods are characterized by high extractant costs, high volatility, and poor safety, making them unsuitable for environmentally friendly production. The development of new, efficient, and environmentally friendly extractants has attracted widespread attention. Ionic liquids are a new type of extractant with low vapor pressure and high stability, but they suffer from high production costs and poor decomposition potential. Low eutectic solvents have properties similar to ionic liquids, with the advantages of extremely low vapor pressure and good thermal and chemical stability. Furthermore, low eutectic solvents are easy to prepare and have good biodegradability, attracting widespread attention from researchers. Currently, a specific extraction method suitable for the accurate separation of vanadium, arsenic, and tungsten in the purification process of vanadium crystals after alkaline treatment of waste SCR catalysts is lacking. Summary of the Invention [Problem to be solved by the invention]

[0004] To solve this problem, the present invention provides a method for extracting and separating vanadium from a vanadium-arsenic solution using a hydrophobic low eutectic solvent. The hydrophobic low eutectic solvent can be used to accurately separate vanadium, arsenic, and tungsten from vanadium crystals. Furthermore, the extraction and separation process of the present invention does not require adjusting the pH of the solution; after mixing the hydrophobic low eutectic solvent with the vanadium-arsenic solution, the target vanadium-arsenic solution system is adjusted to an appropriate range. [Means for solving the problem]

[0005] In a first aspect, the present invention provides a method for extracting and separating vanadium from a vanadium-arsenic solution using a hydrophobic low eutectic solvent. This method includes the following steps: In S100, a hydrophobic low eutectic solvent is prepared. Specifically, a hydrogen bond acceptor and a hydrogen bond donor are mixed and reacted to form a hydrogen bond network. The hydrogen bond acceptor includes tetrabutylammonium chloride or tetrabutylammonium bromide, and the hydrogen bond donor includes one of n-octanol, n-nonanol, and n-decanol. In S200, vanadium is extracted and separated. Specifically, the hydrophobic low eutectic solvent and the vanadium-arsenic solution are mixed, vibrated, and allowed to stand for phase separation, followed by back-extraction.

[0006] The present invention first provides a hydrophobic low eutectic solvent for accurately separating vanadium, arsenic, and tungsten from vanadium crystals. The hydrogen-bond network formed by this hydrophobic low eutectic solvent can effectively extract vanadium ions from a vanadium-arsenic solution while exhibiting low reactivity to other ions. Next, the present invention enables the effective extraction of vanadium ions from a vanadium-arsenic solution by back-extraction using a NaCl solution as a back-extractant. This vanadium-arsenic solution is a dissolution medium for vanadium crystals, and exhibits a high single-stage extraction rate of vanadium. Preferably, the hydrogen-bond acceptor comprises tetrabutylammonium bromide, and the hydrogen-bond donor comprises n-octanol.

[0007] In some embodiments, in step S100, the reaction temperature is 65°C to 85°C, the reaction time is 3 to 5 hours, and the stirring speed is 100 to 200 RPM. Preferably, the reaction temperature is 70°C to 80°C, the reaction time is 4 to 5 hours, and the stirring speed is 180 to 200 RPM. When the reaction conditions between a specific hydrogen bond acceptor and a specific hydrogen bond donor are within the above ranges, the resulting hydrogen bond network is advantageous for extracting vanadium ions from the vanadium arsenic solution and has very low response to other ions.

[0008] In some embodiments, in step S100, the molar ratio of the hydrogen bond acceptor to the hydrogen bond donor is 1:(1 to 1.4). Preferably, the molar ratio of the hydrogen bond acceptor to the hydrogen bond donor is 1:1.2.

[0009] In some embodiments, the viscosity of the hydrophobic low eutectic solvent is 110 cP to 180 cP. Preferably, the viscosity of the hydrophobic low eutectic solvent is 115 cP to 130 cP. When the viscosity of the hydrophobic low eutectic solvent is appropriate, it is more advantageous for the movement of the dispersed droplets during the vibration process after mixing with the vanadium arsenic solution and for phase separation after extraction, further improving the single-stage extraction rate of vanadium.

[0010] In some embodiments, the step of mixing the hydrophobic low eutectic solvent and the vanadium arsenic solution includes mixing the hydrophobic low eutectic solvent and the vanadium arsenic solution in a volume ratio of 1:(1-2). Preferably, the hydrophobic low eutectic solvent and the vanadium arsenic solution are mixed in a volume ratio of 1:1.

[0011] In some embodiments, the vanadium ion concentration in the vanadium arsenic solution is 9 g / L to 12 g / L, the arsenic ion concentration is 8 g / L to 8.5 g / L, and the vanadium arsenic solution further includes 0.3 g / L to 0.4 g / L of tungsten ions, 0.08 g / L to 1 g / L of silicon ions, and 0.4 g / L to 0.6 g / L of phosphorus ions.

[0012] In some embodiments, in step S200, the vibration is performed at 40° C. to 60° C. for 8 to 12 minutes, and the standing time for the standing separation phase is 30 to 50 minutes.

[0013] In some embodiments, the vibration amplitude is between 38mm and 42mm and the rotation frequency is between 280RPM and 320RPM.

[0014] In some embodiments, in step S200, the stripping after phase separation includes obtaining a vanadium-loaded hydrophobic low eutectic solvent (loaded organic phase) after phase separation, mixing the stripping agent and the vanadium-loaded hydrophobic low eutectic solvent in a volume ratio of (3-5):1, and vibrating the mixture for 5-10 minutes to perform stripping. The concentration of the NaCl solution used as the stripping agent is 1.5 mol / L-2 mol / L. [Effects of the Invention]

[0015] The beneficial effects of the technical solution of the present invention include at least the following: The hydrogen-bonding network formed by the hydrophobic low eutectic solvent described in this application can effectively extract vanadium ions from vanadium-arsenic solutions, while at the same time reducing the extraction rate of other ions. Furthermore, the method described in this application can be applied to accurately separate vanadium from impurity ions such as arsenic and tungsten in vanadium crystals. The use of the hydrophobic low eutectic solvent described in this application eliminates the need to adjust the pH value of the solution during the extraction and separation of vanadium and arsenic, making the operation simple, economical, and safe, significantly reducing the safety risks during the extraction process and demonstrating good prospects for the extraction and separation of vanadium and arsenic. DETAILED DESCRIPTION OF THE INVENTION

[0016] In order to further clarify the objectives, technical solutions and advantages of the present invention, the present invention will be described in more detail below in combination with examples and comparative examples. The specific examples described herein are merely for the purpose of illustrating the present invention, and are not intended to limit the present invention. A hypoeutectic solvent is a binary or ternary hypoeutectic mixture that combines a specific chemical metric ratio of hydrogen bond donors (HBDs) and hydrogen bond acceptors (HBAs). Because of the extensive hydrogen bond network present in hypoeutectic solvents, their viscosity at room temperature is several tens of times higher than that of water. The viscosity of hypoeutectic solvents can be effectively reduced by increasing the temperature or the content of hydrogen bond donors. Currently, a hypoeutectic solvent and corresponding extraction separation method specifically applicable to the precise separation of vanadium and arsenic in the purification process of vanadium crystals are lacking.

[0017] A method for extracting and separating vanadium from a vanadium-arsenic solution using a hydrophobic low eutectic solvent, comprising the steps of:

[0018] In step S100, a hydrophobic low eutectic solvent is prepared. A hydrogen bond acceptor and a hydrogen bond donor are mixed and reacted to form a hydrogen bond network. The hydrogen bond acceptor includes tetrabutylammonium chloride or tetrabutylammonium bromide, and the hydrogen bond donor includes n-octanol, n-nonanol, or n-decanol.

[0019] In the S200, vanadium is extracted and separated by mixing a hydrophobic low eutectic solvent with a vanadium-arsenic solution, extracting by shaking, allowing to stand for separation, and then back-extracting after phase separation.

[0020] In some embodiments, the hydrogen bond acceptor includes tetrabutylammonium bromide and the hydrogen bond donor includes n-octanol.

[0021] In some embodiments, in step S100, the reaction temperature of the reaction is 65° C. to 85° C., the reaction time is 3 hours to 5 hours, and the stirring speed is 100 RPM to 200 RPM.

[0022] By way of example, the reaction temperature for the reaction is 65°C, 70°C, 75°C, 80°C, 85°C, or a range consisting of any two of the foregoing values.

[0023] By way of example, the aforementioned reaction times are 3 hours, 3.5 hours, 4 hours, 4.5 hours, 5 hours, or a range consisting of any two of the foregoing values.

[0024] By way of example, the agitation speed for the aforementioned reaction is 100 RPM, 120 RPM, 140 RPM, 150 RPM, 160 RPM, 180 RPM, 200 RPM, or a range consisting of any two of the foregoing values.

[0025] In some embodiments, in step S100, the molar ratio of the hydrogen bond acceptor to the hydrogen bond donor is 1:(1 to 1.4).

[0026] Illustratively, the molar ratio of the hydrogen bond acceptor to the hydrogen bond donor is 1:1, 1:1.2, 1:1.3, 1:1.4, or a range consisting of any two of the foregoing values.

[0027] In some embodiments, the viscosity of the hydrophobic low eutectic solvent is between 110 cP and 180 cP.

[0028] Illustratively, the viscosity of the hydrophobic low eutectic solvent is 110 cP, 115 cP, 120 cP, 125 cP, 130 cP, 135 cP, 150 cP, 160 cP, 180 cP, or a range consisting of any two of the foregoing values.

[0029] In some embodiments, the step of mixing the hydrophobic low eutectic solvent and the vanadium arsenic solution includes mixing the hydrophobic low eutectic solvent and the vanadium arsenic solution in a volume ratio of 1:(1-2).

[0030] Illustratively, the volume ratio of the hydrophobic low eutectic solvent to the vanadium arsenic solution is 1:1, 1:1.2, 1:1.4, 1:1.5, 1:1.6, 1:1.8, 1:2, or a range consisting of any two of the foregoing values.

[0031] In some embodiments, the vanadium ion concentration in the vanadium arsenic solution is 9 g / L to 12 g / L, the arsenic ion concentration is 8 g / L to 8.5 g / L, and the vanadium arsenic solution further includes 0.3 g / L to 0.4 g / L of tungsten ions, 0.08 g / L to 1 g / L of silicon ions, and 0.4 g / L to 0.6 g / L of phosphorus ions.

[0032] In some embodiments, in step S200, the vibration includes vibration for 8 to 12 minutes under conditions of 40° C. to 60° C., and the standing time of the standing separation phase is 30 to 50 minutes.

[0033] In some embodiments, the vibration amplitude is between 38mm and 42mm and the rotation frequency is between 280RPM and 320RPM.

[0034] In some embodiments, in step S200, the stripping after phase separation is performed by mixing the stripping agent and the vanadium-loaded hydrophobic low eutectic solvent in a volume ratio of (3-5):1, and vibrating the mixture for 5-10 minutes. The concentration of the NaCl solution used as the stripping agent is 1.5 mol / L-2 mol / L.

[0035] Unless otherwise specified, the reagents used in the following examples can be purchased from ordinary biochemical reagent stores, and the methods used in the following examples are all conventional methods in the art unless otherwise specified.

[0036] The vanadium crystals were dissolved, and the resulting vanadium crystal solution had a pH of 13. In the following examples and comparative examples, the vanadium crystal solution (i.e., vanadium-arsenic solution) was studied, and the contents of the main elements are shown in Table 1.

[0037] [Table 1]

[0038] Example 1 Tetrabutylammonium chloride was used as the hydrogen bond acceptor and n-octanol as the hydrogen bond donor, with a molar ratio of 1:1.2. The hydrophobic low eutectic solvent was prepared by heating at 75°C and stirring at 180 RPM for 4 hours. The prepared hydrophobic low eutectic solvent was mixed with the vanadium-arsenic solution in a 1:1 ratio and shaken at 50°C for 10 minutes at 40 mm amplitude and 300 RPM. The mixture was then allowed to stand for 30 minutes for phase separation to obtain the loaded organic phase. The vanadium-loaded low eutectic solvent was mixed with a 1.5 mol / L NaCl solution in a 4:1 ratio and shaken for 10 minutes for back-extraction. The extraction yields for each step were calculated, and the results are shown in Table 2.

[0039] <Example 2> Tetrabutylammonium chloride was used as the hydrogen bond acceptor and n-nonanol as the hydrogen bond donor. The molar ratio of hydrogen bond acceptor to hydrogen bond donor was 1:1.2. The mixture was heated to 75°C and stirred at 180 RPM for 4 hours to prepare a hydrophobic low eutectic solvent. The prepared hydrophobic low eutectic solvent was mixed with the vanadium-arsenic solution in a 1:1 ratio and shaken at 50°C for 10 minutes at a 40 mm amplitude and 300 RPM. The mixture was then allowed to stand for 30 minutes for phase separation to obtain the loaded organic phase. The vanadium-loaded low eutectic solvent was mixed with a 1.5 mol / L NaCl solution in a 4:1 ratio and shaken for 10 minutes for back-extraction. The extraction yields for each step were calculated, and the results are shown in Table 2.

[0040] Example 3 Tetrabutylammonium chloride was used as the hydrogen bond acceptor and n-decanol as the hydrogen bond donor, with a molar ratio of 1:1.2 between the hydrogen bond acceptor and the hydrogen bond donor. The reaction was conducted at 75°C for 4 hours with a stirring speed of 180 RPM to prepare a hydrophobic low eutectic solvent. The prepared hydrophobic low eutectic solvent was mixed with the vanadium-arsenic solution in a 1:1 ratio and shaken at ambient temperature of 50°C with a 40 mm amplitude and a 300 RPM rotation frequency for 10 minutes. The mixture was then allowed to stand for 30 minutes for phase separation to obtain the loaded organic phase. The vanadium-loaded low eutectic solvent was mixed with a 1.5 mol / L NaCl solution in a 4:1 ratio and back-extracted with shaking for 10 minutes. The extraction yields for each step were calculated, and the results are shown in Table 2.

[0041] Example 4 Tetrabutylammonium bromide was used as the hydrogen bond acceptor and n-octanol as the hydrogen bond donor, with a molar ratio of 1:1.2 between the hydrogen bond acceptor and the hydrogen bond donor. The reaction was conducted for 4 hours at 75°C with a stirring speed of 180 RPM to prepare a hydrophobic low eutectic solvent. The prepared hydrophobic low eutectic solvent was mixed with the vanadium-arsenic solution in a 1:1 ratio and shaken at ambient temperature of 50°C with a 40 mm amplitude and a 300 RPM rotation frequency for 10 minutes. The mixture was then allowed to stand for 30 minutes for phase separation to obtain the loaded organic phase. The vanadium-loaded low eutectic solvent was mixed with a 1.5 mol / L NaCl solution in a 4:1 ratio and shaken for 10 minutes for back-extraction. The extraction yields for each step were calculated, and the results are shown in Table 2.

[0042] <Example 5> Tetrabutylammonium bromide was used as the hydrogen bond acceptor and n-nonanol as the hydrogen bond donor, with a molar ratio of 1:1.2 between the hydrogen bond acceptor and the hydrogen bond donor. The reaction was conducted for 4 hours at 75°C with a stirring speed of 180 RPM to prepare a hydrophobic low eutectic solvent. The prepared hydrophobic low eutectic solvent was mixed with the vanadium-arsenic solution in a 1:1 ratio and shaken at ambient temperature of 50°C with a 40 mm amplitude and a 300 RPM rotation frequency for 10 minutes. The mixture was then allowed to stand for 30 minutes for phase separation to obtain the loaded organic phase. The vanadium-loaded low eutectic solvent was mixed with a 1.5 mol / L NaCl solution in a 4:1 ratio and shaken for 10 minutes for back-extraction. The extraction yields for each step were calculated, and the results are shown in Table 2.

[0043] Example 6 Tetrabutylammonium bromide was used as the hydrogen bond acceptor and n-decanol as the hydrogen bond donor, with a molar ratio of 1:1.2 between the hydrogen bond acceptor and the hydrogen bond donor. The reaction was conducted at 75°C for 4 hours with a stirring speed of 180 RPM to prepare a hydrophobic low eutectic solvent. The prepared hydrophobic low eutectic solvent was mixed with the vanadium-arsenic solution in a 1:1 ratio and shaken at ambient temperature of 50°C with a 40 mm amplitude and a 300 RPM rotation frequency for 10 minutes. The mixture was then allowed to stand for 30 minutes for phase separation to obtain the loaded organic phase. The vanadium-loaded low eutectic solvent was mixed with a 1.5 mol / L NaCl solution in a 4:1 ratio and shaken for 10 minutes for back-extraction. The extraction yields for each step were calculated, and the results are shown in Table 2.

[0044] Example 7 Tetrabutylammonium bromide was used as the hydrogen bond acceptor and n-octanol as the hydrogen bond donor, with a 1:1 molar ratio of hydrogen bond acceptor to hydrogen bond donor. The reaction was conducted at 75°C for 4 hours with a stirring speed of 180 RPM to prepare a hydrophobic low eutectic solvent. The prepared hydrophobic low eutectic solvent was mixed with the vanadium-arsenic solution in a 1:1 ratio and shaken at ambient temperature of 50°C with a 40 mm amplitude and a 300 RPM rotation frequency for 10 minutes. The mixture was then allowed to stand for 30 minutes for phase separation to obtain the loaded organic phase. The vanadium-loaded low eutectic solvent was mixed with a 1.5 mol / L NaCl solution in a 4:1 ratio and shaken for 10 minutes for back-extraction. The extraction yields for each step were calculated, and the results are shown in Table 2.

[0045] Example 8 Tetrabutylammonium bromide was used as the hydrogen bond acceptor and n-octanol as the hydrogen bond donor, with a molar ratio of 1:1.1 between the hydrogen bond acceptor and the hydrogen bond donor. The reaction was conducted for 4 hours at 75°C with a stirring speed of 180 RPM to prepare a hydrophobic low eutectic solvent. The prepared hydrophobic low eutectic solvent was mixed with the vanadium-arsenic solution in a 1:1 ratio and shaken at ambient temperature of 50°C with a 40 mm amplitude and a 300 RPM rotation frequency for 10 minutes. The mixture was then allowed to stand for 30 minutes for phase separation to obtain the loaded organic phase. The vanadium-loaded low eutectic solvent was mixed with a 1.5 mol / L NaCl solution in a 4:1 ratio and shaken for 10 minutes for back-extraction. The extraction yields for each step were calculated, and the results are shown in Table 2.

[0046] Example 9 Tetrabutylammonium bromide was used as the hydrogen bond acceptor and n-octanol as the hydrogen bond donor, with a molar ratio of 1:1.3 between the hydrogen bond acceptor and the hydrogen bond donor. The reaction was conducted at 75°C for 4 hours with a stirring speed of 180 RPM to prepare a hydrophobic low eutectic solvent. The prepared hydrophobic low eutectic solvent was mixed with the vanadium arsenic solution in a 1:1 ratio and shaken at ambient temperature of 50°C with a 40 mm amplitude and a 300 RPM rotation frequency for 10 minutes. The mixture was then allowed to stand for 30 minutes for phase separation to obtain the loaded organic phase. The vanadium-loaded low eutectic solvent was mixed with a 1.5 mol / L NaCl solution in a 4:1 ratio and shaken for 10 minutes for back-extraction. The extraction yields for each step were calculated, and the results are shown in Table 2.

[0047] Example 10 Tetrabutylammonium bromide was used as the hydrogen bond acceptor and n-octanol as the hydrogen bond donor, with a molar ratio of 1:1.4 between the hydrogen bond acceptor and the hydrogen bond donor. The reaction was conducted at 75°C for 4 hours with a stirring speed of 180 RPM to prepare a hydrophobic low eutectic solvent. The prepared hydrophobic low eutectic solvent was mixed with the vanadium-arsenic solution in a 1:1 ratio and shaken at ambient temperature of 50°C with a 40 mm amplitude and a 300 RPM rotation frequency for 10 minutes. The mixture was then allowed to stand for 30 minutes for phase separation to obtain the loaded organic phase. The vanadium-loaded low eutectic solvent was mixed with a 1.5 mol / L NaCl solution in a 4:1 ratio and shaken for 10 minutes for back-extraction. The extraction yields for each step were calculated, and the results are shown in Table 2.

[0048] Example 11 Tetrabutylammonium bromide was used as the hydrogen bond acceptor and n-octanol as the hydrogen bond donor, with a molar ratio of 1:1.2 between the hydrogen bond acceptor and the hydrogen bond donor. The reaction was conducted for 4 hours at 65°C with a stirring speed of 180 RPM to prepare a hydrophobic low eutectic solvent. The prepared hydrophobic low eutectic solvent was mixed with the vanadium arsenic solution in a 1:1 ratio and shaken at ambient temperature of 50°C with a 40 mm amplitude and a 300 RPM rotation frequency for 10 minutes. The mixture was then allowed to stand for 30 minutes for phase separation to obtain the loaded organic phase. The vanadium-loaded low eutectic solvent was mixed with a 1.5 mol / L NaCl solution in a 4:1 ratio and shaken for 10 minutes for back-extraction. The extraction yields for each step were calculated, and the results are shown in Table 2.

[0049] Example 12 Tetrabutylammonium bromide was used as the hydrogen bond acceptor and n-octanol as the hydrogen bond donor, with a molar ratio of 1:1.2 between the hydrogen bond acceptor and the hydrogen bond donor. The reaction was conducted for 4 hours at 85°C with a stirring speed of 180 RPM to prepare a hydrophobic low eutectic solvent. The prepared hydrophobic low eutectic solvent was mixed with the vanadium-arsenic solution in a 1:1 ratio and shaken at ambient temperature of 50°C with a 40 mm amplitude and a 300 RPM rotation frequency for 10 minutes. The mixture was then allowed to stand for 30 minutes for phase separation to obtain the loaded organic phase. The vanadium-loaded low eutectic solvent was mixed with a 1.5 mol / L NaCl solution in a 4:1 ratio and shaken for 10 minutes for back-extraction. The extraction yields for each step were calculated, and the results are shown in Table 2.

[0050] Example 13 Tetrabutylammonium bromide was used as the hydrogen bond acceptor and n-octanol as the hydrogen bond donor, with a molar ratio of 1:1.2 between the hydrogen bond acceptor and the hydrogen bond donor. The reaction was conducted for 5 hours at 75°C with a stirring speed of 130 RPM to prepare a hydrophobic low eutectic solvent. The prepared hydrophobic low eutectic solvent was mixed with the vanadium arsenic solution in a 1:1 ratio and shaken at ambient temperature of 45°C with a 40 mm amplitude and a 300 RPM rotation frequency for 8 minutes. The mixture was then allowed to stand for 45 minutes for phase separation to obtain the loaded organic phase. The vanadium-loaded low eutectic solvent was mixed with a 1.8 mol / L NaCl solution in a 5:1 ratio and back-extracted with shaking for 10 minutes. The extraction yields for each step were calculated, and the results are shown in Table 2.

[0051] <Comparative Example 1> Tetrapropylammonium chloride was used as the hydrogen bond acceptor and n-octanol as the hydrogen bond donor, with a molar ratio of 1:1.2 between the hydrogen bond acceptor and the hydrogen bond donor. The reaction was conducted for 4 hours at 75°C with a stirring speed of 180 RPM to prepare a hydrophobic low eutectic solvent. The prepared hydrophobic low eutectic solvent was mixed with the vanadium-arsenic solution in a 1:1 ratio and shaken at ambient temperature of 50°C with a 40 mm amplitude and a 300 RPM rotation frequency for 10 minutes. The mixture was then allowed to stand for 30 minutes for phase separation to obtain the loaded organic phase. The vanadium-loaded low eutectic solvent was mixed with a 1.5 mol / L NaCl solution in a 4:1 ratio and back-extracted with shaking for 10 minutes. The extraction yields for each step were calculated, and the results are shown in Table 2.

[0052] <Comparative Example 2> Tetrabutylammonium chloride was used as the hydrogen bond acceptor and n-hexanol as the hydrogen bond donor, with a molar ratio of 1:1.2 between the hydrogen bond acceptor and the hydrogen bond donor. The reaction was conducted for 4 hours at 75°C with a stirring speed of 180 RPM to prepare a hydrophobic low eutectic solvent. The prepared hydrophobic low eutectic solvent was mixed with the vanadium-arsenic solution in a 1:1 ratio and shaken at ambient temperature of 50°C with a 40 mm amplitude and a rotation frequency of 300 RPM for 10 minutes. The mixture was then allowed to stand for 30 minutes for phase separation to obtain the loaded organic phase. The vanadium-loaded low eutectic solvent was mixed with a 1.5 mol / L NaCl solution in a 4:1 ratio and shaken for 10 minutes for back-extraction. The extraction yields for each step were calculated, and the results are shown in Table 2.

[0053] [Table 2]

[0054] As can be seen from Table 2, Example 4 is the optimal example. Specifically, when the hydrogen bond acceptor is tetrabutylammonium bromide and the hydrogen bond donor is n-octanol, tetrabutylammonium bromide and n-octanol are mixed in a molar ratio of 1:1.2 and reacted for 4 hours at 75°C and 180 RPM. The resulting hydrophobic low eutectic solvent has the most favorable vanadium extraction effect, with a single-stage vanadium extraction rate of 80.21%. Replacing tetrabutylammonium bromide with tetrabutylammonium chloride results in a higher single-stage vanadium extraction rate of over 75%, whereas replacing tetrabutylammonium bromide with tetrapropylammonium chloride results in a single-stage vanadium extraction rate of only 45.78%. When other fatty alcohols (e.g., n-nonanol and n-decanol) are used, the single-stage extraction rate of vanadium reaches over 65%, while when n-hexanol is used, the single-stage extraction rate of vanadium reaches only 38.54%. This shows that the hydrogen bond network formed by suitable hydrogen bond donors and hydrogen bond acceptors under certain reaction conditions is more favorable for the extraction of vanadium from vanadium arsenic solution.

[0055] The above-described contents are only preferred embodiments of the present invention, and do not limit the present invention. All modifications, equivalent replacements and improvements made within the spirit and principle of the present invention are included in the protection scope of the present invention.

Claims

1. A method for extracting and separating vanadium from a vanadium-arsenic solution using a hydrophobic low eutectic solvent, comprising: A step S100 of preparing a hydrophobic low eutectic solvent in which a hydrogen bond acceptor and a hydrogen bond donor are mixed and reacted to form a hydrogen bond network; and a vanadium extraction and separation step S200 of mixing the hydrophobic low eutectic solvent and the vanadium-arsenic solution, vibrating, allowing to stand for phase separation, and then back-extracting the vanadium after phase separation; the hydrogen bond acceptor comprises tetrabutylammonium chloride or tetrabutylammonium bromide; The hydrogen bond donor includes any one of n-octanol, n-nonanol, and n-decanol. A method for extracting and separating vanadium from a vanadium-arsenic solution using a hydrophobic low eutectic solvent.

2. 2. The method of claim 1, wherein in step S100, the molar ratio of the hydrogen bond acceptor to the hydrogen bond donor is 1:(1 to 1.4).

3. The method of claim 2, wherein in step S100, the molar ratio of the hydrogen bond acceptor to the hydrogen bond donor is 1:1.

2.

4. 2. The method according to claim 1, wherein in step S100, the reaction temperature is 65°C to 85°C, the reaction time is 3 hours to 5 hours, and the stirring speed is 100 RPM to 200 RPM.

5. 2. The method of claim 1, wherein the hydrophobic low eutectic solvent has a viscosity of 110 cP to 180 cP.

6. 6. The method of claim 5, wherein the hydrophobic low eutectic solvent has a viscosity of 115 cP to 130 cP.

7. 2. The method of claim 1, wherein in step S200, mixing the hydrophobic low eutectic solvent and the vanadium arsenic solution comprises mixing the hydrophobic low eutectic solvent and the vanadium arsenic solution in a volume ratio of 1:(1-2).

8. 2. The method according to claim 1, wherein the vanadium arsenic solution has a vanadium ion concentration of 9 g / L to 12 g / L and an arsenic ion concentration of 8 g / L to 8.5 g / L.

9. 2. The method according to claim 1, wherein in step S200, the vibration is performed under conditions of 40°C to 60°C, and the standing time for the standing separation is 30 minutes to 50 minutes.

10. 10. The method according to claim 1, wherein in step S200, the stripping after phase separation is performed by obtaining a vanadium-loaded hydrophobic low eutectic solvent, mixing the stripping agent and the vanadium-loaded hydrophobic low eutectic solvent in a volume ratio of (3-5):1, and vibrating the mixture for 5-10 minutes to perform stripping.

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