A new method for preparing high-purity vanadyl sulfate by short process of vanadium slag calcification roasting, acid leaching and liquid extraction and its product

Abstract

The present application relates to the technical field of high-purity vanadyl sulfate prepared by extraction method short process, in particular to a new method for preparing high-purity vanadyl sulfate by vanadium slag calcification roasting acid leaching liquid extraction method short process, at least comprising the following steps: (1) extraction: the vanadium-containing acid leaching liquid is acidified and then added into an organic phase for extraction to obtain a vanadium-rich organic phase; (2) vanadium-rich organic phase washing: the vanadium-rich organic phase is washed by multiple-stage countercurrent washing with sulfuric acid aqueous solution to obtain an acid-washed vanadium-rich organic phase, then the acid-washed vanadium-rich organic phase is preliminarily purified with a purification liquid to obtain a preliminarily purified vanadium-rich organic phase, and then pure water is added into the preliminarily purified vanadium-rich organic phase for washing and phase separation to obtain a purified vanadium-rich organic phase; (3) reverse extraction of the purified vanadium-rich organic phase: the purified vanadium-rich organic phase is added with a reverse extraction liquid for reverse extraction treatment to obtain a vanadyl sulfate aqueous solution, which has a short process flow, a small amount of reagent, a low production cost and is easy to realize industrial application.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of high-purity vanadyl sulfate prepared by extraction method, and particularly relates to a new method for preparing high-purity vanadyl sulfate by extraction method of vanadium slag calcification roasting acid leaching solution and a product thereof. BACKGROUND

[0002] In recent years, with the continuous progress of science and technology, the full vanadium redox flow battery in the field of new energy such as photovoltaic and wind power and micro-grid large-scale energy storage has become a new industry. The electrolyte is the core of the vanadium battery, and the main component is high-purity vanadyl sulfate solution. The quality of the electrolyte directly determines the energy storage capacity of the vanadium battery. How to prepare high-purity vanadyl sulfate solution at low cost and high efficiency is the key to the preparation of vanadium electrolyte, and is of great significance to the development of vanadium battery.

[0003] The traditional preparation method of high-purity vanadyl sulfate solution is to use high-purity V2O5 as raw material, add a reducing agent, reduce the pentavalent vanadium to tetravalent vanadium in a sulfuric acid system, and finally obtain high-purity vanadyl sulfate solution. However, there are several problems in preparing high-purity vanadyl sulfate solution from high-purity V2O5. First, the purity of the raw material V2O5 is required to be high, the preparation process is complex, and the cost is high. Second, high-purity sulfuric acid needs to be dissolved and a reducing agent needs to be added for reduction, and the process is also complex, which not only increases the cost, but also easily introduces impurities.

[0004] The vanadium concentration of the vanadium slag calcification roasting acid leaching solution is 28-38 g / L, the vanadium concentration is relatively high, and the content of heavy metal impurities such as Fe is relatively low, which is relatively suitable for preparing high-purity vanadyl sulfate. If the vanadium leaching solution is taken as the research object, high-purity vanadyl sulfate solution is directly prepared from the vanadium solution, and the intermediate process of preparing high-purity vanadium pentoxide solid is omitted, which will greatly shorten the preparation process of high-purity vanadyl sulfate and reduce the production cost. Therefore, it is necessary to develop a low-cost and short-process method for preparing high-purity vanadyl sulfate by taking the vanadium-containing solution as the research object. Chinese patent (publication number CN 110066929A) discloses a preparation method of vanadyl sulfate solution, which uses vanadium slag calcification roasting leaching solution or vanadium precipitation wastewater as raw material to prepare high-purity vanadyl sulfate. However, it needs to be reduced under acidic conditions and then extracted twice, and finally treated with activated carbon to obtain vanadyl sulfate solution and waste activated carbon. The production efficiency still needs to be further improved, which limits the industrialization and application. SUMMARY

[0005] In order to solve the above problems, the present application provides a new method for preparing high-purity vanadyl sulfate by extraction method of vanadium slag calcification roasting acid leaching solution, which has a short process flow, a small amount of reagent, a low production cost and is easy to realize industrial application.

[0006] In one aspect, the present application provides a new method for preparing high-purity vanadyl sulfate by extraction method of vanadium slag calcification roasting acid leaching solution, which at least includes the following steps:

[0007] (1) Extraction: After the vanadium-containing acid leaching solution is acidified, it is added to an organic phase to obtain a vanadium-rich organic phase;

[0008] (2) Washing of the vanadium-rich organic phase: After the vanadium-rich organic phase is washed by multiple stages of countercurrent washing with a sulfuric acid aqueous solution, an acid-washed vanadium-rich organic phase is obtained, and then the acid-washed vanadium-rich organic phase is preliminarily purified with a purification liquid to obtain a preliminarily purified vanadium-rich organic phase, and then the preliminarily purified vanadium-rich organic phase is washed with pure water, and after standing and phase separation, a purified vanadium-rich organic phase is obtained;

[0009] (3) Back extraction of the purified vanadium-rich organic phase: after the purified vanadium-rich organic phase is back extracted with a back extraction liquid, a vanadyl sulfate aqueous solution is obtained.

[0010] The pH of the vanadium-containing acid leaching solution in step (1) is 2.8-3.0 at 25°C, and the acid leaching solution contains elements including V, Mn, Mg, Ti, P, Fe, Cr, Ca, Si, Al, NH4 + , and one or more of the above.

[0011] The vanadium-containing acid leaching solution in step (1) is a vanadium slag calcification roasting acid leaching solution, and the pH of the vanadium slag calcification roasting acid leaching solution is 2.8-3.0 at 25°C. The vanadium slag calcification roasting acid leaching solution contains elements including V, Mn, Mg, Ti, P, Fe, Cr, Ca, Si, Al, NH4 + .

[0012] As a preferred technical solution, the acidification treatment in step (1) is specifically adjusting the pH of the vanadium-containing acid leaching solution to 1.8-2.0.

[0013] As a preferred technical solution, the organic phase in step (1) includes an organic amine extractant, an alcohol regulator, and an inert diluent, wherein the organic amine extractant is selected from at least one of trioctylamine and tri-n-octylamine, the alcohol regulator is selected from one of isooctanol, isodecanol, and secondary octanol, and the inert diluent is one of an alkane, benzene, carbon tetrachloride, and kerosene.

[0014] Most preferably, the organic phase is a combination of trioctylamine (N235), isooctanol, and sulfonated kerosene. Preferably, the volume ratio of the trioctylamine (N235), isooctanol, and sulfonated kerosene is (1.5-2):1:(7-7.5).

[0015] As a preferred technical solution, the volume ratio of the vanadium-containing acid leaching solution to the organic phase in step (1) is (4-5):1.

[0016] As a preferred technical solution, the organic phase in step (1) has been pre-acidified to transform N235.

[0017] Preferably, the extraction in step (1) is: stirring for 3-5 min at 20-30℃, and obtaining the vanadium-rich organic phase after phase separation.

[0018] The vanadium-containing acid leaching solution, especially the vanadium slag calcification roasting acid leaching solution, has a high vanadium concentration, but still contains some impurity elements, which affects the subsequent preparation of high-purity vanadyl sulfate solution meeting the application requirements of vanadium battery electrolyte. The elements contained in the actual vanadium slag calcification roasting acid leaching solution include V, Mn, Mg, Ti, P, Fe, Cr, Ca, Si, Al, NH4 + , which greatly increases the processing difficulty. In order to prepare high-purity vanadyl sulfate solution from vanadium slag calcification roasting acid leaching solution containing multiple impurity elements, the inventors first optimize the pH of the vanadium slag calcification roasting acid leaching solution to 1.8-2.0, so as to reduce the extraction of impurity ions in the vanadium slag calcification roasting acid leaching solution into the vanadium-rich organic phase as much as possible. When the pH of the vanadium slag calcification roasting acid leaching solution is less than 1.8, three phases are generated during the extraction process, and the extraction cannot be carried out. When the pH is greater than 2.0, the impurity ion concentration in the high-purity vanadyl sulfate solution is high, which cannot meet the requirements of vanadium battery electrolyte. This is determined by the trioctyldecyl tertiary amine + isooctanol + sulfonated kerosene extraction system in the present application.

[0019] As a preferred technical solution, the concentration of the sulfuric acid aqueous solution in step (2) is 65-75 g / L.

[0020] As a preferred technical solution, the volume ratio of the sulfuric acid aqueous solution to the vanadium-rich organic phase in step (2) is 1:1.

[0021] As a preferred technical solution, the multi-stage countercurrent washing in step (2) is three-stage countercurrent washing, the washing temperature is 20-30℃, and the washing time is 5-10 min.

[0022] As a preferred technical solution, the purification solution in step (2) is a sulfuric acid aqueous solution containing hydrogen peroxide, the concentration of hydrogen peroxide in the sulfuric acid aqueous solution containing hydrogen peroxide is 110-150 g / L (based on the volume of the sulfuric acid aqueous solution), and the concentration of sulfuric acid is 80-120 g / L.

[0023] As a preferred technical solution, the volume ratio of the purification solution to the vanadium-rich organic phase after acid washing in step (2) is 1:(2.5-3).

[0024] As a preferred technical solution, the preliminary purification treatment in step (2) is: stirring and reacting for 2-3 h at 70-90℃, cooling and standing after the reaction is completed, and obtaining the preliminary purified vanadium-rich organic phase after phase separation.

[0025] Further, by matching the optimization of the washing mode, especially after adopting the aqueous sulfuric acid solution with a concentration of 65-75 g / L to carry out three-stage countercurrent washing on the vanadium-rich organic phase, then adopting the aqueous sulfuric acid solution containing hydrogen peroxide to stir and react the acid-washed vanadium-rich organic phase at 70-90 DEG C for 2-3 h, the impurity ion types in the vanadium-rich organic phase are effectively reduced, and the loss of vanadium is also as small as possible, so that the preliminarily purified vanadium-rich organic phase is obtained, and finally, the vanadium-rich organic phase containing impurities is washed by pure water to become a purified vanadium-rich organic phase, and the purified organic phase has removed most of the main impurity ions such as manganese, iron and titanium, and the content of other impurity ions is extremely low.

[0026] As a preferred technical solution, the stripping solution in step (3) is high-concentration aqueous sulfuric acid solution containing hydrogen peroxide, the concentration of hydrogen peroxide in the high-concentration aqueous sulfuric acid solution containing hydrogen peroxide is 200-250 g / L (based on the volume of the aqueous sulfuric acid solution), and the concentration of sulfuric acid is 230-250 g / L.

[0027] As a preferred technical solution, the volume ratio of the stripping solution and the purified vanadium-rich organic phase in step (3) is 1:(2.4-3).

[0028] As a preferred technical solution, the temperature of the stripping treatment is 85 DEG C-90 DEG C, and the time is 20 min-30 min.

[0029] Finally, the purified vanadium-rich organic phase is stirred and reacted at 85 DEG C-90 DEG C for 20 min-30 min using high-concentration aqueous sulfuric acid solution containing hydrogen peroxide, vanadyl ions in the organic phase are reduced to tetravalent vanadium cations, vanadium enters the aqueous phase, and no new impurities are introduced, and finally, a high-purity vanadyl sulfate solution is formed.

[0030] The present application realizes a short process for preparing a high-purity vanadyl sulfate aqueous solution meeting the requirements of vanadium battery electrolyte from vanadium slag calcification roasting acid leaching solution containing various impurities by optimizing the design method including extraction, washing of vanadium-rich organic phase and stripping of purified vanadium-rich organic phase, without performing multiple extraction-stripping steps, avoiding the introduction of additional impurities, greatly improving production efficiency and production economy, and having extremely high market promotion value.

[0031] In the present application, the hydrogen peroxide is hydrogen peroxide with a mass concentration of 30%, and the sulfuric acid is sulfuric acid with a mass concentration of 98%.

[0032] The present application also provides a high-purity vanadyl sulfate aqueous solution prepared by a short process of vanadium slag calcification roasting acid leaching solution extraction method, wherein the content of main impurity elements is: Mn≤5 mg / L, Ti≤30 mg / L, Fe≤50 mg / L, which meets the electrolyte standard GB / T37204-2018 for all-vanadium liquid flow battery.

[0033] The third aspect of the present application provides a high-purity vanadyl sulfate aqueous solution prepared by a short process of vanadium slag calcification roasting acid leaching liquid extraction method for application in a vanadium battery.

[0034] Advantages

[0035] 1. The present application provides a new method for preparing high-purity vanadyl sulfate by a short process of vanadium slag calcification roasting acid leaching liquid extraction method, which has a short process, low reagent consumption, low production cost, and is easy to realize industrial application.

[0036] 2. In order to prepare high-purity vanadyl sulfate solution from vanadium slag calcification roasting acid leaching liquid containing various impurity elements, the pH of the vanadium slag calcification roasting acid leaching liquid is optimized to 1.8-2.0 to reduce the extraction of impurity ions in the vanadium slag calcification roasting acid leaching liquid into the vanadium-rich organic phase as much as possible.

[0037] 3. Further, by optimizing the washing method, especially by first using a 65-75 g / L sulfuric acid aqueous solution to perform three-stage countercurrent washing of the vanadium-rich organic phase to obtain the acid-washed vanadium-rich organic phase, and then using a hydrogen peroxide-containing sulfuric acid aqueous solution to stir and react the acid-washed vanadium-rich organic phase at 70-90°C for 2-3 h, the types of impurity ions in the vanadium-rich organic phase are effectively reduced, and the loss of vanadium is also as small as possible, obtaining a preliminarily purified vanadium-rich organic phase.

[0038] 4. Finally, the purified vanadium-rich organic phase is stirred and reacted with a high-concentration hydrogen peroxide-containing sulfuric acid aqueous solution at 85-90°C for 20-30 min, the vanadyl ions in the organic phase are reduced to tetravalent vanadium cations, and vanadium enters the aqueous phase without introducing new impurities, finally forming a high-purity vanadyl sulfate solution.

[0039] 5. The present application optimizes the design method including extraction, washing of vanadium-rich organic phase, and purification of vanadium-rich organic phase stripping steps, realizes a short process for preparing high-purity vanadyl sulfate aqueous solution meeting the requirements of vanadium battery electrolyte from vanadium slag calcification roasting acid leaching liquid containing various impurities, does not need to perform multiple extraction-stripping steps, avoids the introduction of additional impurities, greatly improves production efficiency and production economy, and has extremely high market promotion value. DETAILED DESCRIPTION

[0040] Example 1

[0041] Example 1 of the present application provides a new method for preparing high-purity vanadyl sulfate by a short process of vanadium slag calcification roasting acid leaching liquid extraction method, which includes the following steps:

[0042] (1) Extraction: After acidification treatment, the vanadium-containing acid leaching liquid is added to the organic phase for extraction to obtain a vanadium-rich organic phase;

[0043] (2) The acid-washed vanadium-rich organic phase is obtained by multi-stage countercurrent washing of the vanadium-rich organic phase with a sulfuric acid aqueous solution, and then the acid-washed vanadium-rich organic phase is preliminarily purified with a purification liquid to obtain a preliminarily purified vanadium-rich organic phase, and then 150 mL of pure water is added to the preliminarily purified vanadium-rich organic phase for washing for 10 min, and the purified vanadium-rich organic phase is obtained after phase separation.

[0044] (3) The purified vanadium-rich organic phase is back-extracted by adding a back-extraction liquid to the purified vanadium-rich organic phase, and then a vanadyl sulfate aqueous solution is obtained.

[0045] The vanadium-containing acid leaching solution in step (1) is a vanadium slag calcification roasting acid leaching solution, the pH of the vanadium slag calcification roasting acid leaching solution is 2.98 at 25°C, and the elemental composition of the acid leaching solution is shown in Table 1.

[0046] Table 1

[0047]

[0048] The acidification treatment in step (1) is specifically adjusting the pH of 600 mL of the vanadium-containing acid leaching solution to 2.0.

[0049] The organic phase is a combination of tricaprylyl tertiary amine (N235), isooctanol, and sulfonated kerosene. The volume ratio of the tricaprylyl tertiary amine (N235), isooctanol, and sulfonated kerosene is 1.5:1:7.5.

[0050] The volume ratio of the vanadium-containing acid leaching solution and the organic phase in step (1) is 4:1.

[0051] The organic phase in step (1) has been pre-acidified to convert N235.

[0052] The extraction in step (1) is stirring for 5 min at 25°C, and then 150 mL of a vanadium-rich organic phase is obtained after phase separation.

[0053] The concentration of the sulfuric acid aqueous solution in step (2) is 65 g / L.

[0054] The volume ratio of the sulfuric acid aqueous solution and the vanadium-rich organic phase in step (2) is 1:1.

[0055] The multi-stage countercurrent washing in step (2) is three-stage countercurrent washing, the washing temperature is 25°C, and the washing time is 10 min, and then 150 mL of an acid-washed vanadium-rich organic phase is obtained.

[0056] The purification liquid in step (2) is a sulfuric acid aqueous solution containing hydrogen peroxide, the concentration of hydrogen peroxide in the sulfuric acid aqueous solution containing hydrogen peroxide is 120 g / L (based on the volume of the sulfuric acid aqueous solution), and the concentration of sulfuric acid is 80 g / L.

[0057] The volume ratio of the stripping solution to the purified vanadium-rich organic phase in step (3) is 1:3.

[0058] The preliminary purification treatment in step (2) is stirring and reacting for 2h at 80℃, and after the reaction is completed, cooling and standing, and phase separation to obtain 150mL of the preliminary purified vanadium-rich organic phase.

[0059] The stripping solution in step (3) is a high-concentration sulfuric acid aqueous solution containing hydrogen peroxide, and the concentration of hydrogen peroxide in the high-concentration sulfuric acid aqueous solution containing hydrogen peroxide is 200g / L (based on the volume of the sulfuric acid aqueous solution), and the concentration of sulfuric acid is 230g / L.

[0060] The volume ratio of the stripping solution to the purified vanadium-rich organic phase in step (3) is 1:3.

[0061] The temperature of the stripping treatment is 85℃, and the time is 30min.

[0062] The organic phase (containing 15% N235 extraction organic phase) in this embodiment extracts 30% of vanadium in the acidic vanadium solution, and the final vanadium recovery rate of the prepared product vanadyl sulfate is 85.8%.

[0063] The hydrogen peroxide in this embodiment is hydrogen peroxide with a mass concentration of 30%, and the sulfuric acid is sulfuric acid with a mass concentration of 98%.

[0064] Example 2

[0065] Example 2 of the present application provides a new method for preparing high-purity vanadyl sulfate by a short process of vanadium slag calcification roasting and acid leaching liquid extraction, which comprises the following steps:

[0066] (1) Extraction: After acidification treatment, the vanadium-containing acid leaching liquid is added into the organic phase for extraction to obtain a vanadium-rich organic phase;

[0067] (2) Washing of the vanadium-rich organic phase: After multi-stage countercurrent washing of the vanadium-rich organic phase with sulfuric acid aqueous solution, an acid-washed vanadium-rich organic phase is obtained, and then the acid-washed vanadium-rich organic phase is subjected to preliminary purification treatment with a purification solution to obtain a preliminary purified vanadium-rich organic phase, and then 120mL of purified water is added to the preliminary purified vanadium-rich organic phase for washing for 10min, and after standing and phase separation, a purified vanadium-rich organic phase of 120mL is obtained.

[0068] (3) Stripping of the purified vanadium-rich organic phase: after adding a stripping solution to the purified vanadium-rich organic phase for stripping treatment, a vanadyl sulfate aqueous solution is obtained.

[0069] The vanadium-containing acid leaching liquid in step (1) is the same as in Example 1.

[0070] The acidification treatment in step (1) is specifically adjusting the pH of 600mL of vanadium-containing acid leaching liquid to 1.8.

[0071] The organic phase is a combination of trioctyldecyl tertiary amine (N235), iso-octanol, and sulfonated kerosene. The volume ratio of trioctyldecyl tertiary amine (N235), iso-octanol, and sulfonated kerosene is 2.0:1:7.0.

[0072] The volume ratio of the vanadium-containing acid leaching solution and the organic phase in step (1) is 5:1.

[0073] The organic phase in step (1) has been pre-acidified to transform N235.

[0074] The extraction in step (1) is stirring for 3 min at 25°C, and 120 mL of vanadium-rich organic phase is obtained after phase separation.

[0075] The concentration of the aqueous sulfuric acid solution in step (2) is 75 g / L.

[0076] The volume ratio of the aqueous sulfuric acid solution and the vanadium-rich organic phase in step (2) is 1:1.

[0077] The multi-stage countercurrent washing in step (2) is three-stage countercurrent washing, the washing temperature is 25°C, the washing time is 10 min, and 120 mL of the vanadium-rich organic phase after acid washing is obtained.

[0078] The purification liquid in step (2) is an aqueous sulfuric acid solution containing hydrogen peroxide, the concentration of hydrogen peroxide in the aqueous sulfuric acid solution containing hydrogen peroxide is 133 g / L (based on the volume of the aqueous sulfuric acid solution), and the concentration of sulfuric acid is 120 g / L.

[0079] The volume ratio of the purification liquid and the vanadium-rich organic phase after acid washing in step (2) is 45:120.

[0080] The preliminary purification treatment in step (2) is stirring at 80°C for 3 h, and after the reaction is completed, the reaction is cooled and allowed to stand, and 120 mL of the preliminary purified vanadium-rich organic phase is obtained after phase separation.

[0081] The stripping liquid in step (3) is a high-concentration aqueous sulfuric acid solution containing hydrogen peroxide, the concentration of hydrogen peroxide in the high-concentration aqueous sulfuric acid solution containing hydrogen peroxide is 240 g / L (based on the volume of the aqueous sulfuric acid solution), and the concentration of sulfuric acid is 250 g / L.

[0082] The volume ratio of the stripping liquid and the purified vanadium-rich organic phase in step (3) is 1:2.4.

[0083] The temperature of the stripping treatment is 90°C, and the time is 20 min.

[0084] The organic phase (containing 20% N235 extraction organic phase) in this example extracts 40% of the vanadium in the acidic vanadium solution, and the final vanadium recovery rate of the prepared product vanadyl sulfate is 88.2%.

[0085] The hydrogen peroxide in the embodiment is hydrogen peroxide with a mass concentration of 30%, and the sulfuric acid is sulfuric acid with a mass concentration of 98%.

[0086] Embodiment 3

[0087] The embodiment 3 of the present application provides a new method for preparing high-purity vanadyl sulfate by short process of vanadium slag calcification roasting acid leaching liquid extraction, comprising the following steps:

[0088] (1) Extraction: After the vanadium-containing acid leaching liquid is acidified and treated, it is added into an organic phase to extract to obtain a vanadium-rich organic phase;

[0089] (2) Washing of the vanadium-rich organic phase: After the vanadium-rich organic phase is washed by multiple stages of countercurrent washing with a sulfuric acid aqueous solution, an acid-washed vanadium-rich organic phase is obtained, and then the acid-washed vanadium-rich organic phase is subjected to preliminary purification treatment with a purification liquid to obtain a preliminarily purified vanadium-rich organic phase, and then 140 mL of pure water is added to the preliminarily purified vanadium-rich organic phase for washing for 10 min, and after standing and phase separation, a purified vanadium-rich organic phase of 140 mL is obtained.

[0090] (3) Reverse extraction of the purified vanadium-rich organic phase: after adding a reverse extraction liquid to the purified vanadium-rich organic phase for reverse extraction treatment, a vanadyl sulfate aqueous solution is obtained.

[0091] The vanadium-containing acid leaching liquid in step (1) is the same as in embodiment 1.

[0092] The acidification treatment in step (1) is specifically: the pH of 600 mL of the vanadium-containing acid leaching liquid is adjusted to 1.9.

[0093] The organic phase is a combination of trioctyldecyl tertiary amine (N235), isooctanol and sulfonated kerosene. The volume ratio of the trioctyldecyl tertiary amine (N235), isooctanol and sulfonated kerosene is 1.7:1:7.3.

[0094] The volume ratio of the vanadium-containing acid leaching liquid to the organic phase in step (1) is 4.3:1.

[0095] The organic phase in step (1) has been pre-acidified to transform N235.

[0096] The extraction in step (1) is: stirring for 4 min at 25°C, and after phase separation, 140 mL of a vanadium-rich organic phase is obtained.

[0097] The concentration of the sulfuric acid aqueous solution in step (2) is 70 g / L.

[0098] The volume ratio of the sulfuric acid aqueous solution to the vanadium-rich organic phase in step (2) is 1:1.

[0099] The multistage countercurrent washing in step (2) is three-stage countercurrent washing, the washing temperature is 25℃, and the washing time is 10 min, to obtain 120 mL of the post-acid washing vanadium-rich organic phase.

[0100] The purification liquid in step (2) is a hydrogen peroxide-containing sulfuric acid aqueous solution, the concentration of hydrogen peroxide in the hydrogen peroxide-containing sulfuric acid aqueous solution is 113 g / L (based on the volume of the sulfuric acid aqueous solution), and the concentration of sulfuric acid is 100 g / L.

[0101] The volume ratio of the purification liquid to the post-acid washing vanadium-rich organic phase in step (2) is 55:140.

[0102] The preliminary purification treatment in step (2) is stirring reaction at 80℃ for 2.5 h, cooling and standing after the reaction is completed, and phase separation to obtain 140 mL of the preliminary purified vanadium-rich organic phase.

[0103] The stripping liquid in step (3) is a high-concentration hydrogen peroxide-containing sulfuric acid aqueous solution, the concentration of hydrogen peroxide in the high-concentration hydrogen peroxide-containing sulfuric acid aqueous solution is 204 g / L (based on the volume of the sulfuric acid aqueous solution), and the concentration of sulfuric acid is 240 g / L.

[0104] The volume ratio of the stripping liquid to the purified vanadium-rich organic phase in step (3) is 55:140.

[0105] The temperature of the stripping treatment is 88℃, and the time is 30 min.

[0106] The organic phase (containing 17% N235 extraction organic phase) in the embodiment extracts 34.46% of vanadium in the acidic vanadium solution, and the final vanadium recovery rate of the prepared product vanadyl sulfate is 87.6%.

[0107] The hydrogen peroxide in the embodiment is hydrogen peroxide with a mass concentration of 30%, and the sulfuric acid is sulfuric acid with a mass concentration of 98%.

[0108] Embodiment 4

[0109] Embodiment 4 of the present application provides a new method for preparing high-purity vanadyl sulfate by a short process of vanadium slag calcification roasting acid leaching liquid extraction, which comprises the following steps:

[0110] (1) Extraction: after acidizing treatment, the vanadium-containing acid leaching liquid is added into an organic phase for extraction to obtain a vanadium-rich organic phase;

[0111] (2) Washing of the vanadium-rich organic phase: after multistage countercurrent washing of the vanadium-rich organic phase with a sulfuric acid aqueous solution, a post-acid washing vanadium-rich organic phase is obtained, then a preliminary purification treatment of the post-acid washing vanadium-rich organic phase is performed with a purification liquid to obtain a preliminary purified vanadium-rich organic phase, and then 150 mL of purified water is added into the preliminary purified vanadium-rich organic phase for washing for 10 min, standing and phase separation to obtain 150 mL of a purified vanadium-rich organic phase.

[0112] (3) Purification of the vanadium-rich organic phase: the purified vanadium-rich organic phase is back-extracted with a back-extraction solution to obtain a vanadyl sulfate aqueous solution.

[0113] The vanadium-containing acid leaching solution in step (1) is the same as in Example 1.

[0114] The acidification treatment in step (1) is specifically adjusting the pH of 600 mL of the vanadium-containing acid leaching solution to 2.0.

[0115] The organic phase is a combination of trioctyldecyl tertiary amine (N235), isooctanol, and sulfonated kerosene. The volume ratio of the trioctyldecyl tertiary amine (N235), isooctanol, and sulfonated kerosene is 1.8:1:7.2.

[0116] The volume ratio of the vanadium-containing acid leaching solution and the organic phase in step (1) is 4:1.

[0117] The organic phase in step (1) has been pre-acidified to convert N235.

[0118] The extraction in step (1) is stirring for 4 min at 25°C, and after phase separation, 150 mL of a vanadium-rich organic phase is obtained.

[0119] The concentration of the sulfuric acid aqueous solution in step (2) is 70 g / L.

[0120] The volume ratio of the sulfuric acid aqueous solution and the vanadium-rich organic phase in step (2) is 1:1.

[0121] The multi-stage countercurrent washing in step (2) is three-stage countercurrent washing, the washing temperature is 25°C, and the washing time is 10 min, obtaining 150 mL of the acid-washed vanadium-rich organic phase.

[0122] The purification solution in step (2) is a sulfuric acid aqueous solution containing hydrogen peroxide, the concentration of hydrogen peroxide in the sulfuric acid aqueous solution containing hydrogen peroxide is 112 g / L (based on the volume of the sulfuric acid aqueous solution), and the concentration of sulfuric acid is 100 g / L.

[0123] The volume ratio of the purification solution and the acid-washed vanadium-rich organic phase in step (2) is 1:2.5.

[0124] The preliminary purification treatment in step (2) is stirring and reacting at 80°C for 2.5 h, after the reaction is completed, cooling and standing, and phase separation to obtain 150 mL of the preliminary purified vanadium-rich organic phase.

[0125] The back-extraction solution in step (3) is a high-concentration sulfuric acid aqueous solution containing hydrogen peroxide, the concentration of hydrogen peroxide in the high-concentration sulfuric acid aqueous solution containing hydrogen peroxide is 240 g / L (based on the volume of the sulfuric acid aqueous solution), and the concentration of sulfuric acid is 230 g / L.

[0126] The volume ratio of the stripping solution and the purified vanadium-rich organic phase in step (3) is 1:3.

[0127] The stripping treatment is performed at a temperature of 88°C for 30 min.

[0128] The organic phase (containing 18% N235 extraction organic phase) in the example extracts 36.49% vanadium in the acidic vanadium solution, and the final vanadium recovery rate of the prepared vanadyl sulfate product is 86.9%.

[0129] The hydrogen peroxide in the example is hydrogen peroxide with a mass concentration of 30%, and the sulfuric acid is sulfuric acid with a mass concentration of 98%.

[0130] Comparative Example 1

[0131] The comparative example 1 of the present application provides a preparation method of a vanadyl sulfate solution, and the specific implementation is the same as that of example 1, except that in step (1) extraction, the vanadium-containing acid leaching solution is not subjected to acidification treatment and is directly added into the organic phase for extraction to obtain a vanadium-rich organic phase.

[0132] The organic phase (containing 15% N235 extraction organic phase) in the example extracts 30% vanadium in the acidic vanadium solution, and the final vanadium recovery rate of the prepared vanadyl sulfate product is 86.2%.

[0133] Comparative Example 2

[0134] The comparative example 2 of the present application provides a preparation method of a vanadyl sulfate solution, and the specific implementation is the same as that of example 1, except that in step (2) vanadium-rich organic phase washing, the vanadium-rich organic phase is not subjected to multi-stage countercurrent washing with an aqueous sulfuric acid solution, but is directly subjected to preliminary purification treatment with a purification solution to obtain a preliminarily purified vanadium-rich organic phase, and then 150 mL of pure water is added to the preliminarily purified vanadium-rich organic phase for washing for 10 min, and after standing and phase separation, 150 mL of purified vanadium-rich organic phase is obtained, and the volume ratio of the purification solution to the vanadium-rich organic phase is 1:3.

[0135] The organic phase (containing 15% N235 extraction organic phase) in the example extracts 30% vanadium in the acidic vanadium solution, and the final vanadium recovery rate of the prepared vanadyl sulfate product is 86.9%.

[0136] Comparative Example 3

[0137] The comparative example 3 of the present application provides a preparation method of vanadyl sulfate solution, the specific embodiment of which is the same as that of the example 1, except that in step (2) the washing of the vanadium-rich organic phase: the vanadium-rich organic phase is subjected to multi-stage countercurrent washing with an aqueous sulfuric acid solution to obtain an acid-washed vanadium-rich organic phase, and then the acid-washed vanadium-rich organic phase is not subjected to preliminary purification treatment with a purification liquid, but 150 mL of pure water is directly added to the acid-washed vanadium-rich organic phase for washing for 10 min, and after standing and phase separation, 150 mL of the purified vanadium-rich organic phase is obtained.

[0138] The organic phase (containing 15% N235 extraction organic phase) in the example extracts 30% of vanadium in the acidic vanadium solution, and the final vanadium recovery rate of the prepared product vanadyl sulfate is 95.2%.

[0139] Comparative example 4

[0140] The comparative example 4 of the present application provides a preparation method of vanadyl sulfate solution, the specific embodiment of which is the same as that of the example 1, except that in step (2) the washing of the vanadium-rich organic phase: the vanadium-rich organic phase is not subjected to multi-stage countercurrent washing with an aqueous sulfuric acid solution to obtain a vanadium-rich organic phase, and the vanadium-rich organic phase is also not subjected to preliminary purification treatment with a purification liquid, but 150 mL of pure water is directly added to the vanadium-rich organic phase for washing for 10 min, and after standing and phase separation, 150 mL of the purified vanadium-rich organic phase is obtained.

[0141] The organic phase (containing 15% N235 extraction organic phase) in the example extracts 30% of vanadium in the acidic vanadium solution, and the final vanadium recovery rate of the prepared product vanadyl sulfate is 95.2%.

[0142] Performance test method

[0143] The vanadyl sulfate solutions of examples 1-4 and comparative examples 1-4 are subjected to ammonium ferrous sulfate titration to determine the concentration of vanadium in the solutions. The ICP (inductively coupled plasma emission spectrometer) is used to test the impurity element content in the vanadyl sulfate solutions obtained by the examples, and the element content of the vanadyl sulfate solutions is shown in Tables 2 and 3.

[0144] Table 2

[0145] Example V concentration / g / L Mn concentration / mg / L Ti concentration / mg / L Fe concentration / mg / L Example 1 76.50 0.028 22.47 49.89 Example 2 80.20 0.029 24.59 49.62 Example 3 78.90 0.031 30.0 48.89 Example 4 77.60 0.029 29.9 36.5 Comparative Example 1 77.30 0.032 86.77 50.0 Comparative Example 2 76.52 0.035 29.98 85.92 Comparative Example 3 76.65 47.13 28.8 49.3 Comparative Example 4 77.80 53.22 59.9 95.07

[0146] Table 3

[0147] Ingredient / mg / L V / g / L Mn Mg Ti Fe P Cr Al Ca Example 1 76.5 0.028 <0.01 22.47 49.89 0.015 0.01 0.001 0.001 Ingredient / mg / L As Si K Na Cu NH4 + ]]> Example 1 <0.001 <0.005 <0.001 <0.001 <0.001 0.1

[0148] As shown in the test results of the examples in Tables 2 and 3, the vanadyl sulfate prepared using the present invention's short-process method of calcining, roasting, and acid leaching has a V concentration of ≥1.5 mol / L, and its impurity content meets the requirements of GB / T37204-2018. Therefore, the vanadyl sulfate prepared using the present invention's short-process method of calcining, roasting, and acid leaching meets the requirements of GB / T37204-2018, the standard for electrolytes for all-vanadium redox flow batteries.

Claims

1. A novel method for preparing high-purity vanadyl sulfate by a short-process method of vanadium slag calcination roasting and acid leaching extraction, characterized in that: At least the following steps are included: (1) Extraction: The vanadium-containing acid leaching solution is acidified and then added to the organic phase for extraction to obtain a vanadium-rich organic phase; (2) Washing of the vanadium-rich organic phase: The vanadium-rich organic phase is subjected to multi-stage countercurrent washing with a sulfuric acid aqueous solution to obtain an acid-washed vanadium-rich organic phase, and then the acid-washed vanadium-rich organic phase is subjected to preliminary purification treatment with a purification liquid to obtain a preliminary purified vanadium-rich organic phase, and then pure water is added to the preliminary purified vanadium-rich organic phase for washing, and the phases are allowed to stand for phase separation to obtain a purified vanadium-rich organic phase; (3) Back-extraction of the purified vanadium-rich organic phase: adding a stripping solution to the purified vanadium-rich organic phase for back-extraction to obtain a vanadyl sulfate aqueous solution; The acidification treatment in step (1) is specifically as follows: adjusting the pH of the vanadium-containing acid leaching solution to 1.8-2.0; The organic phase in step (1) comprises an organic amine extractant, an alcohol regulator and an inert diluent, wherein the organic amine extractant is selected from at least one of trioctyldecyl tertiary amine and tri-n-octylamine, the alcohol regulator is selected from one of isooctyl alcohol, isodecanol and sec-octanol, and the inert diluent is one of alkanes, benzene, carbon tetrachloride and kerosene.

2. The novel method for preparing high-purity vanadyl sulfate by a short-process method of vanadium slag calcination roasting and acid leaching extraction according to claim 1, characterized in that: The pH of the vanadium-containing acid leaching solution in step (1) is 2.8-3.0 at 25°C, and the elements contained in the acid leaching solution include V, Mn, Mg, Ti, P, Fe, Cr, Ca, Si, Al, NH4 + One or more of .

3. The novel method for preparing high-purity vanadyl sulfate by a short-process method of vanadium slag calcination roasting and acid leaching extraction according to claim 1, characterized in that: The concentration of the sulfuric acid aqueous solution in step (2) is 65-75 g / L.

4. The novel method for preparing high-purity vanadyl sulfate by a short-process method of vanadium slag calcination roasting and acid leaching extraction according to claim 1, characterized in that: The purification liquid in step (2) is an aqueous solution of sulfuric acid containing hydrogen peroxide.

5. The novel method for preparing high-purity vanadyl sulfate by a short-process method of vanadium slag calcination roasting and acid leaching extraction according to claim 1, characterized in that: The preliminary purification treatment in step (2) is as follows: stirring the reaction at 70-90° C. for 2-3 hours, cooling and standing after the reaction, and phase separation to obtain a preliminary purified vanadium-rich organic phase.

6. The novel method for preparing high-purity vanadyl sulfate by a short-process method of vanadium slag calcination roasting and acid leaching extraction according to claim 1, characterized in that: In step (3), the stripping solution is a high-concentration sulfuric acid aqueous solution containing hydrogen peroxide, wherein the concentration of hydrogen peroxide in the high-concentration sulfuric acid aqueous solution containing hydrogen peroxide is 200-250 g / L, and the concentration of sulfuric acid is 230-250 g / L.

7. The novel method for preparing high-purity vanadyl sulfate by a short-process method of vanadium slag calcination roasting and acid leaching extraction according to claim 1, characterized in that: The stripping treatment is performed at a temperature of 85° C. to 90° C. and for a time of 20 min to 30 min.

8. A high-purity vanadyl sulfate aqueous solution prepared by the method according to any one of claims 1 to 7.

Images