Method for preparing high-purity vanadyl sulfate through calcification roasting countercurrent leaching extraction

Abstract

The invention belongs to the technical field of high-value utilization of non-ferrous metal solid waste, and relates to a method for preparing high-purity vanadyl sulfate through calcification roasting countercurrent leaching extraction.The method comprises the steps that converter vanadium slag serves as a raw material, a calcification agent is added for roasting, and transformed vanadium slag is obtained; secondary countercurrent is conducted on the transformed vanadium slag, calcium sulfite is added in the leaching process, and reduced vanadium-containing acid leaching liquid is obtained; the leaching residues can be used for preparing ferrotitanium alloy products; vanadium and impurities are separated through the extraction circulation process of extraction, washing and reverse extraction, and the high-purity vanadyl sulfate electrolyte is prepared. According to the method, the converter vanadium slag is adopted as a raw material, and high-value utilization of the converter vanadium slag in the field of energy storage is achieved. And meanwhile, resource utilization of leaching residues obtained through secondary countercurrent leaching is achieved, and whole-process harmless treatment is achieved.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of high-value utilization of non-ferrous metal solid waste, and particularly relates to a method for preparing high-purity vanadyl sulfate through calcification roasting countercurrent leaching and extraction. BACKGROUND

[0002] With the rapid development of the new energy industry, energy storage devices such as vanadium batteries have an increasing demand for high-quality vanadyl sulfate electrolyte. Traditional preparation methods are often complex, high in cost, and strict in raw material requirements. Converter vanadium slag, as an industrial waste residue rich in vanadium, is obtained through low-acid secondary countercurrent leaching to obtain an acid leaching solution directly suitable for extraction separation pH value, which is directly and efficiently converted into vanadyl sulfate electrolyte. This not only realizes the recycling of resources and reduces production costs, but also has important significance for environmental protection. However, the existing technology has many problems in processing converter vanadium slag to prepare electrolyte, such as low vanadium leaching rate, difficulty in effectively removing impurities, and high process energy consumption, and a new optimized process is urgently needed to solve these problems.

[0003] Publication No. CN119120941A discloses a method for extracting vanadium from vanadium slag roasting products and preparing vanadium oxide vanadyl sulfate. The vanadium slag roasting products are crushed and ground, and then subjected to synchronous reduction leaching in a leaching medium. The pH of the leaching solution is adjusted to 0-5 by a pH adjuster. The leaching medium and the roasting products are in a liquid-solid ratio of 3-20:1 to obtain a leaching solution containing divalent vanadium oxide ions. This invention shortens the process flow, but still needs to add a pH adjustment link.

[0004] Publication No. CN113998735B discloses a method for producing vanadyl sulfate battery electrolyte using vanadium-containing acid leaching solution. The method needs to add a reducing agent to the vanadium-containing acid leaching solution for reduction reaction. After the reaction is completed, the pH is adjusted to 1.5-4.0, and the extraction cycle process is carried out. This method reduces the preparation of intermediate product vanadium pentoxide, but it needs to reduce the acid leaching solution first and then adjust the pH to be suitable for extraction, which increases the process flow. SUMMARY

[0005] Technical problems to be solved

[0006] In view of the above shortcomings and deficiencies of the prior art, the present application provides a method for preparing high-purity vanadyl sulfate through calcification roasting countercurrent leaching and extraction, which solves the technical problems of how to improve the recovery rate of vanadium, reduce equipment loss, reduce impurity content, simplify the process flow, reduce production cost, realize the high-value utilization of converter vanadium slag, and promote the industrialization process.

[0007] Technical scheme

[0008] In order to achieve the above purpose, the main technical scheme adopted by the present application includes:

[0009] The application provides a method for preparing high-purity vanadyl sulfate by calcification roasting countercurrent leaching and extraction, comprising the following steps:

[0010] S1, taking converter vanadium slag as raw material, adding a calcification agent to obtain a transformed vanadium slag by roasting;

[0011] S2, performing secondary countercurrent leaching of the transformed vanadium slag by using low-concentration acid, and adding calcium sulfite in the leaching process to obtain a vanadium-containing acid leaching solution after reduction;

[0012] S3, separating vanadium from impurities by an extraction-washing-back extraction cycle process to prepare high-purity vanadyl sulfate electrolyte.

[0013] Optionally, the calcification agent in S1 comprises a calcium salt type calcification agent and an organic type calcification agent calcium gluconate, the calcium salt type calcification agent comprises CaO, Ca 12 H 22 O 14 Ca.

[0014] Optionally, the roasting temperature in S1 is 700-1200 DEG C, the roasting time is 20-180 min, and the calcium-vanadium ratio after adding the calcification agent is (1:1)-(1:20).

[0015] Optionally, the adding mode of the calcification agent in S1 is mechanical stirring mixing, ball milling mixing or airflow mixing; when the mechanical stirring mixing is used, the stirring time is 10-120 min and the stirring rate is 100-5000 r / min; when the ball milling mixing is used, the rotation speed is 40-90% of the critical rotation speed, the grinding time is 10-120 min, and the ball-to-material ratio is (3:1)-(10:1); when the airflow mixing is used, the airflow speed is 10-80 m / s, and the mixing time is 10 s-20 min.

[0016] Optionally, in S2, the low-concentration acid used in the secondary countercurrent leaching is one or more of sulfuric acid, phosphoric acid, oxalic acid, hydrochloric acid, nitric acid and citric acid, and the concentration is 0.5-1.5 mol / L; the temperature of the secondary countercurrent leaching is 10-100 DEG C.

[0017] Optionally, in the extraction-washing-back extraction process in S3, the extractant is a mixed solution of P204 and sulfonated kerosene in a volume ratio of (1:3)-(1:5).

[0018] Optionally, the dilute sulfuric acid solution is used as the washing agent in the washing process, and the concentration is 0.5-1 mol / L.

[0019] Optionally, the sulfuric acid solution with a concentration of 2-3 mol / L is used as the back extraction agent.

[0020] Optionally, the method further comprises:

[0021] The leaching residue obtained by leaching is prepared into ferrotitanium alloy products by adopting an electric arc furnace smelting method, and the smelting temperature is controlled at 1600-1800 DEG C.

[0022] Beneficial effects

[0023] The beneficial effects of the present application are that the method for preparing high-purity vanadyl sulfate by calcification roasting countercurrent leaching and extraction provided by the present application uses converter vanadium slag as raw material, realizes high-value utilization of converter vanadium slag in the energy storage field, realizes resource utilization of the leaching residue obtained by secondary countercurrent leaching, and realizes harmless treatment in the whole process. The method shortens the process flow of vanadyl sulfate preparation, reduces acid concentration and equipment loss by performing secondary countercurrent leaching on the calcification roasting transformed vanadium slag, cancels the pH adjustment process link, and provides a new possibility for preparing vanadyl sulfate electrolyte from converter vanadium slag. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 A process flow diagram of the method for preparing high-purity vanadyl sulfate by calcification roasting countercurrent leaching and extraction provided by the present application is provided. DETAILED DESCRIPTION

[0025] In order to better explain the present application, the following will be described in detail in combination with the accompanying drawings and specific embodiments. Although the exemplary embodiments of the present application are shown in the drawings, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided to enable a clearer, more thorough understanding of the present application and to convey the complete scope of the present application to those skilled in the art.

[0026] Embodiment 1

[0027] In combination Figure 1 The present embodiment provides a method for preparing high-purity vanadyl sulfate by calcification roasting countercurrent leaching and extraction, comprising:

[0028] S1, using converter vanadium slag as raw material, adding a calcifying agent to obtain transformed vanadium slag by calcination;

[0029] S2, performing secondary countercurrent leaching of the transformed vanadium slag with low-concentration acid, and adding calcium sulfite during the leaching process to obtain a reduced vanadium-containing acid leaching solution;

[0030] S3, separating vanadium and impurities by an extraction cycle process of extraction-washing-back extraction to prepare high-purity vanadyl sulfate electrolyte.

[0031] Calcium sulfite is directly added to the leaching process without increasing additional impurities.

[0032] Optionally, the calcifying agent in S1 comprises CaO, C 12 H 22 O 14 Ca.

[0033] Optionally, the calcifying agent in S1 is added by mechanical stirring mixing, ball milling mixing or airflow mixing; when added by mechanical stirring mixing, the stirring time is 10-120 min and the stirring speed is 100-5000 r / min; when added by ball milling mixing, the rotation speed is 40-90% of the critical rotation speed, the grinding time is 10-120 min and the ball-to-material ratio is (3:1)-(10:1); when added by airflow mixing, the airflow speed is 10-80 m / s and the mixing time is 10 s-20 min.

[0034] Optionally, the calcifying agent in S1 is added by mechanical stirring mixing, ball milling mixing or airflow mixing; when added by mechanical stirring mixing, the stirring time is 10-120 min and the stirring speed is 100-5000 r / min; when added by ball milling mixing, the rotation speed is 40-90% of the critical rotation speed, the grinding time is 10-120 min and the ball-to-material ratio is (3:1)-(10:1); when added by airflow mixing, the airflow speed is 10-80 m / s and the mixing time is 10 s-20 min.

[0035] Optionally, in S2, the low-concentration acid used in the secondary countercurrent leaching is one or more of sulfuric acid, phosphoric acid, oxalic acid, hydrochloric acid, nitric acid and citric acid, and the concentration is 0.5-1.5 mol / L; the temperature of the secondary countercurrent leaching is 10-100℃.

[0036] Optionally, in S2, the low-concentration acid used in the secondary countercurrent leaching is one or more of sulfuric acid, phosphoric acid, oxalic acid, hydrochloric acid, nitric acid and citric acid, and the concentration is 0.5-1.5 mol / L; the temperature of the secondary countercurrent leaching is 10-100℃. Figure 1 , the secondary countercurrent leaching process comprises adding a low-concentration acid to the transformed vanadium slag to obtain a first leaching residue and a secondary leaching solution, purifying the secondary leaching solution to obtain a vanadyl sulfate electrolyte, adding a new low-concentration acid to the first leaching residue as a leaching agent to obtain a secondary leaching residue and a primary leaching solution, extracting a rich-iron residue from the secondary leaching residue, and adding the primary leaching solution to the transformed vanadium slag to repeat the above process.

[0037] By precisely controlling the acid concentration, the effective leaching of vanadium elements in the transformed vanadium slag can be ensured, and equipment corrosion and unnecessary side reactions caused by excessively high acid concentration can be avoided. In this temperature range, the rate and efficiency of the leaching reaction can achieve a good balance, which is conducive to improving the content of vanadium loaded in the leaching solution, the PH value and the leaching rate of vanadium.

[0038] Optionally, in the extraction-washing-reverse extraction process in S3, the extractant is a mixed solution of P204 (di-(2-ethylhexyl) phosphoric acid) and sulfonated kerosene in a volume ratio of (1:3)-(1:5).

[0039] The extractant system has good selectivity and extraction capacity for vanadium.

[0040] Optionally, the washing process uses a dilute sulfuric acid solution as the washing agent, with a concentration of 0.5 mol / L-1 mol / L. This can effectively wash away the impurity ions in the loaded organic phase.

[0041] Optionally, the stripping uses a sulfuric acid solution with a concentration of 2 mol / L-3 mol / L as the stripping agent. This can efficiently strip the vanadium from the loaded organic phase into the aqueous phase, obtaining a high-purity vanadyl sulfate electrolyte.

[0042] Optionally, the method further comprises:

[0043] The leaching residue obtained by leaching is prepared into ferrotitanium alloy products using an electric arc furnace smelting method, with a smelting temperature controlled at 1600℃-1800℃.

[0044] By precisely controlling the smelting temperature, the titanium and iron in the leaching residue can be fully fused, obtaining ferrotitanium alloy products that meet the quality standards.

[0045] The method uses converter vanadium slag as raw material, realizing high-value utilization of converter vanadium slag in the energy storage field. At the same time, the leaching residue obtained by secondary countercurrent leaching realizes resource utilization, realizing harmless treatment throughout the process. The advantage is that this process can be carried out at room temperature and does not generate intermediate product V2O5, and the energy consumption of the entire process is low, compared with the traditional vanadium extraction process, the energy consumption is reduced by 30%-40%. At the same time, through the comprehensive utilization of converter vanadium slag, the solid waste discharge is reduced, and the environmental pollution is reduced, which has significant environmental benefits. And through the impurity removal pretreatment and multiple purification of the leaching solution, the prepared vanadyl sulfate electrolyte has high purity and can meet the production requirements of high-performance energy storage batteries, providing high-quality raw materials for the energy storage field, and has a broad market application prospect.

[0046] Example 2

[0047] In this embodiment, a company's 100 g converter vanadium slag is used as raw material. Calcium oxide is used as calcium agent, and the calcium-vanadium ratio is 1:5. The mixing is carried out by mechanical stirring mixing method, the stirring time is 10 min, and the stirring rate is 4000 r / min. The mixed raw material is calcined in a tube furnace at 900 ℃ for 60 min to obtain a transformed vanadium slag. A 1 mol / L sulfuric acid solution is used as a low-concentration acid, and a secondary countercurrent leaching is carried out at a temperature of 30 ℃, while calcium sulfite is added, and the molar ratio of calcium sulfite to vanadium in the transformed vanadium slag is 1.2:1, and the leaching time is 40 min, to obtain a reduced vanadium-containing acid leaching solution. The element concentration (mg / L) of the leaching solution is shown in Table 1. The extractant is a mixed solution of P204 and sulfonated kerosene in a volume ratio of 1:3, which is subjected to extraction-washing-reverse extraction process, the washing is carried out with 0.5 mol / L dilute sulfuric acid solution, and the reverse extraction is carried out with 2 mol / L sulfuric acid solution. Finally, a high-purity vanadyl sulfate electrolyte is obtained. The composition (mg / L) of the prepared vanadyl sulfate electrolyte is shown in Table 2, which meets the requirements of the national standard (GB / T37204-2018).

[0048] Table 1

[0049]

[0050] Table 2

[0051]

[0052] Example 2

[0053] A converter vanadium slag of 120 g is weighed, the calcium-vanadium ratio is 1:5, and the mass of added calcium oxide is 24 g. The mixture is fully mixed by ball milling, the rotation speed is 90% of the critical rotation speed, the grinding time is 15 min, and the ball-to-material ratio is 10:1. The transformed vanadium slag is obtained by calcining at 900 ℃ for 90 min. A 0.5 mol / L oxalic acid solution is used as a low-concentration acid, and a secondary countercurrent leaching is carried out at a temperature of 20 ℃, while calcium sulfite is added, and the molar ratio of calcium sulfite to vanadium in the transformed vanadium slag is 1.3:1, and the leaching time is 4 h, to obtain a vanadium-containing acid leaching solution. The extractant is a mixed solution of P204 and sulfonated kerosene in a volume ratio of 1:4, the washing is carried out with 0.7 mol / L dilute sulfuric acid solution, and the reverse extraction is carried out with 2.5 mol / L sulfuric acid solution, to obtain a vanadyl sulfate electrolyte. The leaching residue is smelted in an electric arc furnace at 1500 ℃ to obtain a titanium-iron alloy.

[0054] Example 3

[0055] A converter vanadium slag of 80 g is weighed, and calcium gluconate (C 12 H 22 O 14Ca) as the calcining agent, the ratio of calcium to vanadium is 1:4. The mixture is mixed by air flow mixing method, the air flow speed is 80 m / s, and the mixing time is 10 s. The transformed vanadium slag is obtained by calcining at 750 °C for 2.5 h. The 1 mol / L hydrochloric acid solution is used as the low concentration acid, the molar ratio of the added calcium sulfite to the vanadium in the transformed vanadium slag is 1.4:1, and the leaching is performed at 40 °C for 2.5 h to obtain the vanadium-containing acid leaching solution. The mixed solution of P204 and sulfonated kerosene with a volume ratio of 1:5 is used as the extractant, the 1 mol / L dilute sulfuric acid solution is used for washing, and the 3 mol / L sulfuric acid solution is used for back extraction to obtain the high-purity vanadyl sulfate electrolyte.

[0056] Example 4

[0057] The converter vanadium slag of 150 g is taken, the ratio of calcium to vanadium is 1:20, 7.5 g of calcium oxide is added, the mixture is mixed by mechanical stirring, the stirring time is 120 min, and the stirring speed is 100 r / min. The transformed vanadium slag is obtained by calcining at 850 °C for 2 h. The 1 mol / L phosphoric acid solution is used as the low concentration acid, the molar ratio of the added calcium sulfite to the vanadium in the transformed vanadium slag is 1.5:1, and the leaching is performed at 50 °C for 3.5 h to obtain the vanadium-containing acid leaching solution. The mixed solution of P204 and sulfonated kerosene with a volume ratio of 1:3.5 is used as the extractant, the 0.8 mol / L dilute sulfuric acid solution is used for washing, and the 2.2 mol / L sulfuric acid solution is used for back extraction to prepare the vanadyl sulfate electrolyte.

[0058] Example 5

[0059] The converter vanadium slag of 110 g is taken, the ratio of calcium to vanadium is 1:10, 7.4 g of CaO and 20 g of calcium gluconate (Ca(C 12 H 22 O 14 The mixed calcining agent of CaO and Ca(C

[0060] It is apparent that those skilled in the art can make various modifications and variations to the present application without departing from the spirit and scope of the present application. Thus, the present application should be construed to encompass all such modifications and variations as fall within the scope of the present claims and their equivalents.

[0061] Although the embodiments of the present application have been shown and described above, it is to be understood that the above-described embodiments are merely exemplary and are not to be taken in a limiting sense, but the scope of the present application is not to be understood to be limited to the above-described embodiments but can be variously changed, modified, replaced and varied by those skilled in the art within the scope of the present application.

Claims

1. A method for preparing high-purity vanadyl sulfate by calcination roasting and countercurrent leaching extraction, characterized in that: include: S1, using converter vanadium slag as raw material, adding a calcifying agent and roasting to obtain transformation vanadium slag; S2, performing secondary countercurrent leaching of the transformed vanadium slag with low-concentration acid, and adding calcium sulfite during the leaching process to obtain a reduced vanadium-containing acid leaching solution; S3, through the extraction cycle process of extraction-washing-strip extraction, vanadium is separated from impurities to prepare a high-purity vanadyl sulfate electrolyte.

2. The method for preparing high-purity vanadyl sulfate by calcination roasting countercurrent leaching extraction according to claim 1, characterized in that: The calcifying agent in S1 includes CaO, C 12 H 22 O 14 One of the Ca.

3. The method for preparing high-purity vanadyl sulfate by calcination roasting countercurrent leaching extraction according to claim 2, characterized in that: In S1, the calcination temperature is 700° C.-1200° C., the calcination time is 20 min-180 min, and the calcium-vanadium ratio after adding the calcifying agent is (1:1)-(1:20).

4. The method for preparing high-purity vanadyl sulfate by calcination roasting countercurrent leaching extraction according to claim 3, characterized in that: The calcifying agent is added to S1 by mechanical stirring, ball milling or air flow mixing; when mechanical stirring is used, the stirring time is 10 min-120 min, and the stirring rate is 100 r / min-5000 r / min; when ball milling is used, the rotation speed is 40%-90% of the critical speed, the grinding time is 10 min-120 min, and the ball-to-material ratio is (3:1)-(10:1); when air flow is used, the air flow velocity is 10 m / s-80 m / s, and the mixing time is 10 s-20 min.

5. The method for preparing high-purity vanadyl sulfate by calcination roasting countercurrent leaching extraction according to claim 4, characterized in that: In S2, the low-concentration acid used in the secondary countercurrent leaching is one or more of sulfuric acid, phosphoric acid, oxalic acid, hydrochloric acid, nitric acid, and citric acid, with a concentration of 0.5 mol / L-1.5 mol / L; the temperature of the secondary countercurrent leaching is 10°C-100°C.

6. The method for preparing high-purity vanadyl sulfate by calcination roasting countercurrent leaching extraction according to claim 6, characterized in that: In the S3 extraction-washing-stripping process, the extractant is a mixed solution of P204 and sulfonated kerosene in a volume ratio of (1:3) to (1:5).

7. The method for preparing high-purity vanadyl sulfate by calcination roasting countercurrent leaching extraction according to claim 7, characterized in that: The washing process uses a dilute sulfuric acid solution as a detergent with a concentration of 0.5 mol / L-1 mol / L.

8. The method for preparing high-purity vanadyl sulfate by calcination roasting countercurrent leaching extraction according to claim 8, characterized in that: The back extraction uses a sulfuric acid solution with a concentration of 2mol / L-3mol / L as the back extraction agent.

9. The method for preparing high-purity vanadyl sulfate by calcination roasting countercurrent leaching extraction according to claim 1, characterized in that: The method further comprises: smelting the leached slag obtained by leaching in an electric arc furnace, with the smelting temperature controlled at 1600° C.-1800° C. to prepare a titanium-ferroalloy product.

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