Method for preparing high-purity vanadyl sulfate solution in short process

Abstract

The invention discloses a method for preparing a high-purity vanadyl sulfate solution in a short process. The method comprises the following steps: (1) pretreating stone coal vanadium ore to obtain tailing powder; (2) the tailing powder is mixed with water and concentrated sulfuric acid for curing, vanadium cured ore is obtained, water is added for leaching, and vanadium-containing leachate is obtained; (3) reducing and extracting the vanadium-containing leachate to obtain a first-section loaded organic phase; (4) carrying out reverse extraction on the first-section loaded organic phase, and extracting a reverse extraction solution to obtain a second-section loaded organic phase; and (5) carrying out reverse extraction on the second-section loaded organic phase, and separating a water phase to obtain the high-purity vanadyl sulfate solution. Starting from the stone coal vanadium ore crushing process, the high-purity electrolyte is directly prepared through the curing leaching-neutralization iron removal-two-stage extraction technology, the method has the advantages of being low in cost, environmentally friendly, short in technological process and low in agent consumption and energy consumption, the prepared high-purity vanadyl sulfate solution is high in concentration and purity, and the method is suitable for industrial production. And impurity separation and vanadium enrichment in the vanadium shale acid leaching solution are effectively realized.

Description

Technical Field

[0001] The invention relates to the technical field of liquid flow battery electrolyte, and in particular to a method for directly preparing a high-purity vanadyl sulfate solution from stone coal vanadium ore in a short process. Background Art

[0002] As energy production develops towards renewable energy, domestic and foreign institutions have gradually increased their research on energy storage methods. As an emerging energy storage technology aimed at effectively storing renewable energy, all-vanadium redox flow battery (VRFB) has been partially applied in wind and solar energy storage and power station peak regulation due to its clean, efficient, safe and long service life.

[0003] From a cost perspective, it is important to use low-purity V2O5 to synthesize vanadium electrolytes. Currently, high-purity (99.8%) V2O5 is used as a starting material, while low-purity (98%) V2O5 is usually recovered from slag or catalysts and has also been studied in the industrial sector due to its lower price. However, it is still unclear how impurities in low-purity V2O5 affect the performance of vanadium electrolytes. High-purity vanadyl sulfate solution is an intermediate raw material for the preparation of vanadium battery electrolytes. After obtaining a solution with the required vanadium concentration and impurity content, the valence state of vanadium and its proportional relationship can be adjusted to meet the requirements of vanadium battery electrolytes.

[0004] The existing methods for preparing vanadium electrolyte from stone coal vanadium ore still have the problems of complex process and high cost. For example, the Chinese patent "A method for preparing high-purity electrolyte for vanadium battery from stone coal" (CN101126124B) uses stone coal alkaline roasting and water leaching of vanadium-containing solution to obtain vanadium electrolyte through impurity removal, reduction, vanadium precipitation and sulfuric acid dissolution. This technology still needs to go through multiple reduction and oxidation precipitation and dissolution intermediate links, with complex process, high reagent consumption and energy consumption, serious pollution and high cost. Another example is the Chinese patent "A short-process method for directly preparing vanadium electrolyte from stone coal" (CN118888804A), by first alkali leaching the stone coal vanadium ore powder, then acid leaching, solid-liquid separation, to obtain saturated acid leaching solution and stone coal tailings, CO2 is introduced into the acid leaching solution to remove aluminum, hydrochloric acid is added, and ether and N,N,N',N are added. The mixed solution of '-tetrabutyl adipamide is de-ironized, then concentrated, and the valence state of vanadium ions is regulated, and finally multi-stage extraction and stripping are performed. This solution also has the problems of complex process flow, large amount of additives, high reagent consumption and high cost. Summary of the invention

[0005] The invention provides a method for preparing a high-purity vanadyl sulfate solution by a short process which can effectively shorten the process and reduce the cost, so as to solve the technical problems mentioned in the background technology.

[0006] In order to solve the above technical problems, the technical solution proposed by the present invention is: A method for preparing a high-purity vanadyl sulfate solution in a short process comprises the following steps: (1) Pre-treating stone coal vanadium ore to obtain tailings powder; (2) mixing the tailings powder with water and concentrated sulfuric acid for aging to obtain a vanadium ore, and then adding water to the vanadium ore for leaching, and separating the solid and liquid when the leaching reaches equilibrium to obtain a vanadium-containing leachate; (3) adding a reducing agent to the vanadium-containing leaching solution for reduction to obtain a first-stage extraction stock solution, and extracting the first-stage extraction stock solution with an extractant A to obtain a first-stage loaded organic phase; (4) stripping the first-stage loaded organic phase with a stripping agent, separating the aqueous phase to obtain a stripping solution, adjusting the pH of the stripping solution and extracting with an extractant B to obtain a second-stage loaded organic phase; (5) The second-stage loaded organic phase is stripped using a stripping agent, and the aqueous phase is separated to obtain the high-purity vanadium oxysulfate solution.

[0007] The invention directly prepares a high-purity vanadyl sulfate solution that meets the electrolyte requirements through aging, iron removal and two-stage extraction. First, a vanadium-containing leaching solution is prepared through an aging process. During the aging process, concentrated sulfuric acid will destroy the crystal structure of silicate minerals. Through high temperature and long-term aging, H + Ions enter the lattice of mica and other minerals, causing acid decomposition of vanadium-containing minerals. 3+ Oxidized to soluble V 4+ , molten material appeared on the surface of the mineral, and its main components were KAl(SO4)2, KFe(SO4)2, and KV(SO4)2, indicating that V, Al, Fe and other elements were converted into soluble sulfates during sulfuric acid aging, and then leached by stirring at room temperature to make V 4+Vanadium in the form of vanadium can be leached, and vanadium enters the liquid in the form of vanadyl sulfate. The main chemical components and contents of the vanadium-containing leaching solution are: V is 1.0-3.0 g / L, Al is 4.0-10.0 g / L, Fe is 2.0-5.0 g / L, Mg is 4.0-10.0 g / L, Na is 0.01-0.08 g / L, K is 2.0-6.0 g / L, Ca is 0.1-0.8 g / L, Si is 0.001-0.030 g / L, the concentrations of Si, P and Na impurities in the leaching solution are low, the V leaching effect is good, it does not pollute the environment, and is friendly to the equipment. Then, through the two-stage extraction method, the washing of the loaded organic phase is strengthened, the stripping process is controlled, and the first-stage stripping solution is selected as the means of producing high-purity vanadium sulphate solution products. The goal of preparing vanadium electrolyte from vanadium resources of stone coal vanadium ore in a short process is successfully achieved, avoiding the use of a large amount of reagents and high-temperature reactions, thereby reducing the cost of reagent consumables and streamlining the process flow. It has the characteristics of low cost, environmental friendliness, short process flow, low reagent consumption and low energy consumption. The main components and contents of the high-purity vanadium sulphate solution finally obtained are: V(Ⅳ) is 90-220 g / L, Al concentration is ≤10 mg / L, Fe concentration is ≤60 mg / L, Mg concentration is ≤10 mg / L, Na concentration is ≤50 mg / L, K concentration is ≤10 mg / L, Ca concentration is ≤50 mg / L, and Si concentration is ≤10 mg / L, which meets the national requirements for secondary electrolyte products.

[0008] As a further preferred embodiment of the above technical solution, in step (2), the amount of water added in the aging operation is 20% to 40% of the mass of the tailings powder, and the amount of concentrated sulfuric acid added is 20% to 60% of the mass of the tailings powder.

[0009] As a further preferred embodiment of the above technical solution, in step (2), the temperature of the aging operation is 100-180° C., and the time of the aging operation is 6-24 hours.

[0010] As a further preferred embodiment of the above technical solution, in step (2), the mass ratio of water to vanadium mature ore in the leaching operation is (1-2):1, the leaching temperature is 25-100°C, and the leaching time is 60-360 min.

[0011] As a further preferred embodiment of the above technical solution, in step (3), before reducing the vanadium-containing leaching solution, the pH of the vanadium-containing leaching solution is adjusted to 1.8-2.3; and the reducing agent includes at least one of iron powder, hydrazine hydrate, sodium sulfite, oxalic acid, sodium thiosulfate, citric acid and sulfurous acid.

[0012] As a further preferred embodiment of the above technical solution, in step (3), the extractant A is a P204 extraction system, comprising the following components in parts by weight: 10 to 40 parts of di(2-ethylhexyl) phosphate, 3 to 10 parts of tributyl phosphate and 50 to 87 parts of sulfonated kerosene and solvent oil.

[0013] As a further preferred embodiment of the above technical solution, in step (3), when the first-stage extraction stock solution is extracted with the extractant A, the extraction phase ratio is O / A=1:(1-5); and the extraction time is 2-20 min.

[0014] As a further preferred embodiment of the above technical solution, in step (4), the pH of the stripping solution is adjusted to 2.0-3.2.

[0015] As a further preferred embodiment of the above technical solution, in step (4), the extractant B is a P507 extraction system, comprising the following components in parts by weight: 10 to 40 parts of 2-ethylhexyl mono-2-ethylhexyl phosphate, 3 to 10 parts of tributyl phosphate and 50 to 87 parts of sulfonated kerosene and solvent oil.

[0016] As a further preferred embodiment of the above technical solution, in step (4), when the stripping solution is extracted with extractant B, the extraction phase ratio is O / A=1:(1-5); and the extraction time is 2-20 min.

[0017] As a further preferred embodiment of the above technical solution, after obtaining the first-stage loaded organic phase and the second-stage loaded organic phase, the first-stage loaded organic phase and the second-stage loaded organic phase are washed multiple times with sulfuric acid-acidified water, the pH of the sulfuric acid-acidified water is 1.8~3.0, the washing phase ratio O / A=10:(1~2), the washing time is 6~10 min, and the number of washing times is 1~5 times.

[0018] As a further preferred embodiment of the above technical solution, in step (4) and step (5), the stripping agent is a sulfuric acid solution, the concentration of the sulfuric acid solution is 1-6 mol / L, the stripping ratio O / A=1-5, and the stripping time is 5-20 min.

[0019] As a further preferred embodiment of the above technical solution, in step (1), the pretreatment of the stone coal vanadium ore includes crushing, ball milling, drying and screening in sequence, and the particle size of the obtained tailings powder is 100-400 mesh.

[0020] The present invention has the following beneficial effects: The present invention starts from the stone coal vanadium ore crushing process, and directly prepares a high-purity electrolyte through a mature leaching-neutralization and iron removal-two-stage extraction process. It has the characteristics of low cost, environmental friendliness, short process flow, low reagent consumption and low energy consumption. The prepared high-purity vanadium oxysulfate solution has high concentration and high purity, and effectively realizes the separation of impurities and the enrichment of vanadium in the vanadium shale acidic leaching solution. DETAILED DESCRIPTION

[0021] The present invention is described in detail below in conjunction with the embodiments thereof, but the present invention can be implemented in many different ways as defined and covered by the claims.

[0022] Embodiment 1: The method for preparing a high-purity vanadyl sulfate solution by a short process of this embodiment comprises the following steps: (1) crushing, ball milling, drying and sieving the stone coal vanadium ore to obtain tailings powder; the particle size of the tailings powder is 100 mesh; (2) The tailings powder in step (1) is mixed with pure water and concentrated sulfuric acid, wherein the amount of pure water added is 20% of the mass of the tailings powder, the amount of concentrated sulfuric acid added is 20% of the mass of the tailings powder, the aging temperature is 100°C, and the aging time is 6 hours to obtain vanadium ore; (3) leaching the vanadium mature ore in step (2) with pure water, wherein the mass ratio of pure water to vanadium mature ore is 3, the leaching temperature is 25° C., and the leaching time is 60 min. When the leaching reaches equilibrium, the solid and liquid are separated to obtain a vanadium-containing leachate; The main chemical components of the vanadium-containing leaching solution are: V is 1.12 g / L, Al is 4.21 g / L, Fe is 2.65 g / L, Mg is 4.87 g / L, Na is 0.01 g / L, K is 2.13 g / L, Ca is 0.16 g / L, and Si is 0.001 g / L; (4) The vanadium-containing leaching solution in step (3) is neutralized by adding a pH adjuster, wherein the pH adjuster is sodium hydroxide, and the pH is adjusted to 1.8, and then a reducing agent, iron powder, is added to reduce Fe 3+ , and obtain a section of extract solution; (5) The extract solution in step (4) is extracted with a P204 extraction system. The composition ratio of the P204 extraction system is 10% di(2-ethylhexyl) phosphate + 3% tributyl phosphate + 87% (sulfonated kerosene + 260# solvent oil), and the extraction phase ratio is O / A=2; the extraction time is 2 min, and the loaded organic phase is obtained by phase separation. The loaded organic phase is then washed once with sulfuric acid acidified water. The pH of the sulfuric acid acidified water is 1.8, the washing phase ratio is O / A=10:1, and the washing time is 6 min. The washed loaded organic phase is obtained by phase separation.

[0023] (6) The first loaded organic phase after washing in step (5) is stripped with a stripping agent, wherein the stripping agent is sulfuric acid with a concentration of 1 mol / L, the stripping phase ratio O / A=5, the stripping time is 5 min, and the phases are separated to obtain a stripping solution; (7) The pH of the first stripping solution in step (6) is first adjusted to obtain a second stripping solution, and then extracted with a P507 extraction system. The pH of the second stripping solution is 2.0. The composition ratio of the P507 extraction system is 10% 2-ethylhexyl phosphate mono-2-ethylhexyl ester + 3% tributyl phosphate + 87% (sulfonated kerosene + 260# solvent oil), and the extraction phase ratio is O / A=3; the extraction time is 2 min, and the loaded organic phase is obtained by phase separation. The loaded organic phase is then washed once with sulfuric acid acidified water. The pH of the sulfuric acid acidified water is 1.8, the washing phase ratio is O / A=10:1, and the washing time is 6 min. The washed second stripping organic phase is obtained by phase separation; (8) The second-stage loaded organic phase in step (7) is stripped with a stripping agent, wherein the stripping agent is sulfuric acid with a concentration of 1 mol / L, the stripping ratio O / A=3, the stripping time is 5 min, and the phases are separated to obtain a high-purity vanadium sulfate solution that meets the national requirements for secondary electrolyte products.

[0024] The main chemical components of high-purity vanadyl sulfate solution are: V(Ⅳ) is 90.5 g / L, Al concentration is 9.0 mg / L, Fe concentration is 48.6 mg / L, Mg concentration is 8.3 mg / L, Na concentration is 48.4 mg / L, K concentration is 6.5 mg / L, Ca concentration is 46.6 mg / L, Si concentration is 0.8 mg / L, etc., which meets the national requirements for secondary electrolyte products.

[0025] Embodiment 2: The method for preparing a high-purity vanadyl sulfate solution by a short process of this embodiment comprises the following steps: (1) The stone coal vanadium ore is crushed, ball-milled, dried and sieved to obtain tailings powder; the particle size of the tailings powder is 200 mesh; (2) The tailings powder in step (1) is mixed with pure water and concentrated sulfuric acid, wherein the amount of pure water added is 30% by weight of the tailings powder, the amount of concentrated sulfuric acid added is 60% by weight of the tailings powder, the aging temperature is 150° C., and the aging time is 15 h, to obtain a vanadium ore; (3) leaching the vanadium mature ore in step (2) with pure water, wherein the mass ratio of pure water to vanadium mature ore is 2, the leaching temperature is 100° C., and the leaching time is 360 min. When the leaching reaches equilibrium, the solid and liquid are separated to obtain a vanadium-containing leachate; The main chemical components of the vanadium-containing leaching solution are: V is 2.21 g / L, Al is 6.78 g / L, Fe is 3.58 g / L, Mg is 7.97 g / L, Na is 0.06 g / L, K is 3.07 g / L, Ca is 0.53 g / L, and Si is 0.003 g / L; (4) The vanadium-containing leaching solution in step (3) is neutralized by adding a pH adjuster, wherein the pH adjuster is potassium hydroxide, and the pH is adjusted to 2.0, and then a reducing agent, oxalic acid, is added to reduce Fe 3+ , and obtain a section of extract solution; (5) The extract solution in step (4) is extracted with a P204 extraction system. The composition ratio of the P204 extraction system is 25% di(2-ethylhexyl) phosphate + 5% tributyl phosphate + 70% (sulfonated kerosene + 260# solvent oil), and the extraction phase ratio is O / A = 1:3; the extraction time is 2 min, and the loaded organic phase is obtained by phase separation. The loaded organic phase is then washed once with sulfuric acid acidified water. The pH of the sulfuric acid acidified water is 1.8, the washing phase ratio is O / A = 10:1, and the washing time is 6 min. The washed loaded organic phase is obtained by phase separation.

[0026] (6) The first loaded organic phase after washing in step (5) is stripped with a stripping agent, wherein the stripping agent is sulfuric acid with a concentration of 3 mol / L, the stripping phase ratio O / A=4, the stripping time is 5 min, and the phases are separated to obtain a stripping solution; (7) The pH of the first stripping solution in step (6) is first adjusted to obtain a second stripping solution, and then extracted with a P507 extraction system. The pH of the second stripping solution is 3.2. The composition ratio of the P507 extraction system is 10% 2-ethylhexyl phosphate mono-2-ethylhexyl ester + 3% tributyl phosphate + 87% (sulfonated kerosene + 260# solvent oil), and the extraction phase ratio is O / A=1; the extraction time is 10 min, and the loaded organic phase is obtained by phase separation. The loaded organic phase is then washed three times with sulfuric acid acidified water. The pH of the sulfuric acid acidified water is 2.1, the washing phase ratio is O / A=5:1, and the washing time is 8 min. The washed second stripping organic phase is obtained by phase separation; (8) The second-stage loaded organic phase in step (7) is stripped with a stripping agent, wherein the stripping agent is sulfuric acid with a concentration of 3 mol / L, the stripping ratio O / A=5, the stripping time is 10 min, and the phases are separated to obtain a high-purity vanadium sulfate solution that meets the national requirements for secondary electrolyte products.

[0027] The main chemical components of high-purity vanadyl sulfate solution are: V(Ⅳ) is 112.69 g / L, Al concentration is 4.16 mg / L, Fe concentration is 51.84 mg / L, Mg concentration is 3.77 mg / L, Na concentration is 42.24 mg / L, K concentration is 3.71 mg / L, Ca concentration is 46.47 mg / L, Si concentration is 0.8 mg / L, etc., which meets the national requirements for secondary electrolyte products.

[0028] Embodiment 3: The method for preparing a high-purity vanadyl sulfate solution by a short process of this embodiment comprises the following steps: (1) The stone coal vanadium ore is crushed, ball-milled, dried and sieved to obtain tailings powder; the particle size of the tailings powder is 400 mesh; (2) The tailings powder in step (1) is mixed with pure water and concentrated sulfuric acid, wherein the amount of pure water added is 40% by weight of the tailings powder, the amount of concentrated sulfuric acid added is 40% by weight of the tailings powder, the aging temperature is 180° C., and the aging time is 24 h to obtain vanadium ore; (3) leaching the vanadium mature ore in step (2) with pure water, wherein the mass ratio of pure water to vanadium mature ore is 1, the leaching temperature is 40° C., and the leaching time is 120 min. When the leaching reaches equilibrium, the solid and liquid are separated to obtain a vanadium-containing leachate; The main chemical components of the vanadium-containing leaching solution are: V is 2.98 g / L, Al is 7.43 g / L, Fe is 4.16 g / L, Mg is 6.62 g / L, Na is 0.048 g / L, K is 5.63 g / L, Ca is 0.55 g / L, and Si is 0.016 g / L; (4) The vanadium-containing leaching solution in step (3) is neutralized by adding a pH adjuster, wherein the pH adjuster is sodium carbonate, and the pH is adjusted to 2.3, and then a reducing agent, sodium thiosulfate, is added to reduce Fe 3+ , and obtain a section of extract solution; (5) The extract solution in step (4) is extracted with a P204 extraction system. The composition ratio of the P204 extraction system is 40% di(2-ethylhexyl) phosphate + 10% tributyl phosphate + 50% (sulfonated kerosene + 260# solvent oil), and the extraction phase ratio is O / A=1;2; the extraction time is 20 min, and the loaded organic phase is obtained by phase separation. The loaded organic phase is then washed 5 times with sulfuric acid acidified water. The pH of the sulfuric acid acidified water is 3.0. The washing phase ratio is O / A=10:1. The washing time is 10 min, and the washed loaded organic phase is obtained by phase separation.

[0029] (6) The first loaded organic phase washed in step (5) is stripped with a stripping agent, wherein the stripping agent is sulfuric acid with a concentration of 4 mol / L, the stripping phase ratio O / A=3, the stripping time is 20 min, and phase separation is performed to obtain a stripping solution; (7) The pH of the first stripping solution in step (6) is first adjusted to obtain a second stripping solution, and then extracted with a P507 extraction system. The pH of the second stripping solution is 2.4. The composition ratio of the P507 extraction system is 40% 2-ethylhexyl phosphate mono-2-ethylhexyl ester + 10% tributyl phosphate + 50% (sulfonated kerosene + 260# solvent oil), and the extraction phase ratio is O / A = 1:4; the extraction time is 20 min, and the loaded organic phase is obtained by phase separation. The loaded organic phase is then washed 5 times with sulfuric acid acidified water. The pH of the sulfuric acid acidified water is 3.0, the washing phase ratio is O / A = 4:1, and the washing time is 10 min. The washed second stripping organic phase is obtained by phase separation; (8) The second-stage loaded organic phase in step (7) is stripped with a stripping agent, wherein the stripping agent is sulfuric acid with a concentration of 4 mol / L, the stripping ratio O / A=3, the stripping time is 20 min, and the phases are separated to obtain a high-purity vanadium sulfate solution that meets the national requirements for secondary electrolyte products.

[0030] The main chemical components of high-purity vanadyl sulfate solution are: V(Ⅳ) is 209.43 g / L, Al concentration is 2.89 mg / L, Fe concentration is 40.42 mg / L, Mg concentration is 2.64 mg / L, Na concentration is 22.18 mg / L, K concentration is less than 0.5 mg / L, Ca concentration is 28.77 mg / L, Si concentration is less than 0.5 mg / L, etc., which meets the national requirements for first-class electrolyte.

[0031] The above are only preferred embodiments of the present invention, and the protection scope of the present invention is not limited to the above embodiments. For those skilled in the art, improvements and changes obtained without departing from the technical concept of the present invention should also be regarded as the protection scope of the present invention.

[0032] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A method for preparing high-purity vanadyl sulfate solution in a short process, characterized in that: The following steps are involved: (1) Pre-treating stone coal vanadium ore to obtain tailings powder; (2) mixing the tailings powder with water and concentrated sulfuric acid for aging to obtain a vanadium ore, and then adding water to the vanadium ore for leaching, and separating the solid and liquid when the leaching reaches equilibrium to obtain a vanadium-containing leachate; (3) adding a reducing agent to the vanadium-containing leaching solution for reduction to obtain a first-stage extraction stock solution, and extracting the first-stage extraction stock solution with an extractant A to obtain a first-stage loaded organic phase; (4) stripping the first-stage loaded organic phase with a stripping agent, separating the aqueous phase to obtain a stripping solution, adjusting the pH of the stripping solution and extracting with an extractant B to obtain a second-stage loaded organic phase; (5) The second-stage loaded organic phase is stripped using a stripping agent, and the aqueous phase is separated to obtain the high-purity vanadium oxysulfate solution.

2. The method for preparing high-purity vanadyl sulfate solution by a short process according to claim 1, characterized in that: In step (2), the amount of water added during the aging operation is 20% to 40% of the mass of the tailings powder, and the amount of concentrated sulfuric acid added is 20% to 60% of the mass of the tailings powder.

3. The method for preparing high-purity vanadyl sulfate solution by a short process according to claim 1, characterized in that: In step (2), the temperature of the aging operation is 100-180° C., and the aging operation time is 6-24 hours.

4. The method for preparing high-purity vanadyl sulfate solution by a short process according to claim 1, characterized in that: In step (2), the mass ratio of water to vanadium mature ore in the leaching operation is (1-2):1, the leaching temperature is 25-100°C, and the leaching time is 60-360 min.

5. The method for preparing high-purity vanadyl sulfate solution by a short process according to any one of claims 1 to 4, characterized in that: In step (3), before reducing the vanadium-containing leaching solution, the pH of the vanadium-containing leaching solution is adjusted to 1.8-2.3; the reducing agent includes at least one of iron powder, hydrazine hydrate, sodium sulfite, oxalic acid, sodium thiosulfate, citric acid and sulfurous acid.

6. The method for preparing high-purity vanadyl sulfate solution by a short process according to any one of claims 1 to 4, characterized in that: In step (3), the extractant A is a P204 extraction system, comprising the following components in parts by weight: 10 to 40 parts of di(2-ethylhexyl) phosphate, 3 to 10 parts of tributyl phosphate, and 50 to 87 parts of sulfonated kerosene and solvent oil.

7. The method for preparing high-purity vanadyl sulfate solution by a short process according to claim 6, characterized in that: In step (3), when the first-stage extraction solution is extracted with the extractant A, the extraction phase ratio is O / A=1:(1-5); and the extraction time is 2-20 min.

8. The method for preparing high-purity vanadyl sulfate solution by a short process according to any one of claims 1 to 4, characterized in that: In step (4), the pH of the stripping solution is adjusted to 2.0-3.

2.

9. The method for preparing high-purity vanadyl sulfate solution by a short process according to any one of claims 1 to 4, characterized in that: In step (4), the extractant B is a P507 extraction system, comprising the following components in parts by weight: 10 to 40 parts of 2-ethylhexyl mono-2-ethylhexyl phosphate, 3 to 10 parts of tributyl phosphate, and 50 to 87 parts of sulfonated kerosene and solvent oil.

10. The method for preparing high-purity vanadyl sulfate solution by a short process according to claim 9, characterized in that: In step (4), when the stripping solution is extracted with extractant B, the extraction phase ratio is O / A=1:(1-5); and the extraction time is 2-20 min.

11. The method for preparing high-purity vanadyl sulfate solution by a short process according to any one of claims 1 to 4, characterized in that: After obtaining the first-stage loaded organic phase and the second-stage loaded organic phase, the first-stage loaded organic phase and the second-stage loaded organic phase are washed multiple times with sulfuric acid-acidified water, the pH of the sulfuric acid-acidified water is 1.8-3.0, the washing phase ratio O / A=10:(1-2), the washing time is 6-10 min, and the number of washing times is 1-5 times.

12. The method for preparing high-purity vanadyl sulfate solution by a short process according to any one of claims 1 to 4, characterized in that: In step (4) and step (5), the stripping agent is a sulfuric acid solution, the concentration of the sulfuric acid solution is 1-6 mol / L, the stripping ratio O / A is 1-5, and the stripping time is 5-20 min.

13. The method for preparing high-purity vanadyl sulfate solution by a short process according to any one of claims 1 to 4, characterized in that: In step (1), the pretreatment of the stone coal vanadium ore includes crushing, ball milling, drying and screening in sequence, and the particle size of the obtained tailings powder is 100-400 mesh.