Preparation method of high-purity vanadium pentoxide

Abstract

The invention relates to the technical field of hydrometallurgy, and discloses a preparation method of high-purity vanadium pentoxide, which comprises the following steps: S1, adding a calcium chloride solution and aluminum sulfate into a vanadium-containing leachate, stirring, standing and filtering to obtain a vanadium-containing purified solution; s2, the pH value of the vanadium-containing purified liquid obtained in the step S1 is adjusted to 2-3, the temperature is increased to 60-80 DEG C, ammonium sulfate is added, a stirring reaction is conducted in the boiling state of the solution, and ammonium polyvanadate is obtained after solid-liquid separation; s3, adding water into the ammonium polyvanadate obtained in the step S2 for slurry making and washing, filtering, and drying until the moisture is less than 1%; and S4, adding the ammonium polyvanadate washed in the step S3 into an electric rotary kiln for deamination and calcination. The invention provides a low-cost method for preparing high-purity vanadium pentoxide, and solves the technical problems of low yield and high cost of the existing high-purity vanadium pentoxide preparation process.

Description

Technical Field

[0001] The invention relates to the technical field of hydrometallurgy, and in particular to a method for preparing high-purity vanadium pentoxide. Background Art

[0002] High-purity vanadium pentoxide is an important raw material for the production of vanadium electrolyte, vanadium catalyst, vanadium functional materials and other fine chemicals, and is widely used in aerospace, energy storage, chemical industry and other fields.

[0003] In the prior art, the relevant documents of vanadium pentoxide are as follows: Patent CN117623383A discloses a method for preparing high-purity vanadium pentoxide. The method uses water to slurry the ammonium polyvanadate obtained by precipitating vanadium with acidic ammonium salt in the calcification vanadium extraction process, and then adds ammonia water to dissolve the ammonium polyvanadate after heating to 50-80°C, and then adds aluminum salt or calcium salt. After stirring and reacting for a period of time, carbon dioxide gas is continuously introduced until the pH of the solution becomes 6.5-7.5, and a purified ammonium polyvanadate liquid is obtained by solid-liquid separation; the purified ammonium polyvanadate liquid is cooled to 10-25°C to precipitate ammonium metavanadate, and the ammonium metavanadate is calcined to obtain a high-purity vanadium pentoxide product.

[0004] Patent CN118343833A discloses a method for preparing battery-grade vanadium pentoxide: sodium-roasted vanadium-containing clinker is leached in water to obtain a vanadium-containing leaching solution, the leaching solution is impurity-removed and then vanadium is precipitated through a weakly acidic ammonium salt to obtain sodium ammonium vanadate, the sodium ammonium vanadate is then re-dissolved to precipitate ammonium metavanadate, and the ammonium metavanadate is deaminated and calcined to obtain high-purity vanadium pentoxide (>99.9%).

[0005] Patent CN117383613A discloses a method for preparing vanadium pentoxide, which comprises the following steps: alkali dissolving ammonium polyvanadate or ammonium metavanadate, adding ferric sulfate and sodium sulfate to remove impurities, then adjusting the pH of the filtrate to 8.9, adding sodium dimethyldithiocarbamate, heating and adding copper sulfate to remove impurities again, adding hydrogen peroxide solution to the purified liquid for oxidation, adjusting the pH of the solution to 9.9.8 with ammonia water, adding ammonium salt to precipitate vanadium, then washing with 1wt%-3wt% ammonium chloride solution to remove potassium and sodium, and finally drying and roasting to obtain vanadium pentoxide.

[0006] Patent CN117361624A discloses a method for obtaining high-purity vanadium pentoxide. A vanadium-containing leachate is pretreated to obtain a leachate, and then sodium sulfide is added. After sufficient stirring, sodium thiocarbamide is added and the mixture is allowed to stand for aging. The first impurity removal product is filtered, and then hydrogen peroxide is added and heated for reaction. The pH is adjusted to 8 to 8.5, and then attapulgite is added. After sufficient stirring, aluminum sulfate is added. After sufficient stirring, the mixture is allowed to stand for aging. The second impurity removal product is filtered to obtain a purified leachate. The purified leachate is subjected to vanadium precipitation treatment to obtain ammonium polyvanadate precipitate, which is washed, dried and calcined to obtain vanadium pentoxide with a grade of ≥99.5%.

[0007] Patent CN115010176A discloses a method for preparing high-purity vanadium pentoxide using ammonium metavanadate as a raw material, wherein the ammonium metavanadate is alkali-dissolved and H2O2 and ammonium citrate are added to precipitate vanadium to obtain an ammonium metavanadate product, and finally the ammonium metavanadate product is calcined to obtain high-purity vanadium pentoxide (>99.0%).

[0008] It can be seen from the above patent that currently high-purity powdered vanadium pentoxide is generally produced by calcining ammonium metavanadate. Compared with the technology of producing high-purity vanadium pentoxide using APV, the production of high-purity vanadium pentoxide using ammonium metavanadate mainly has the following problems: ammonium metavanadate is produced by precipitating vanadium with alkaline ammonium salts, the vanadium precipitation efficiency is low, the ammonium salt consumption is large, the residual vanadium concentration in the wastewater is high, the wastewater treatment is difficult, and the production cost is high.

[0009] Therefore, there is still room for improvement in the existing high-purity vanadium pentoxide preparation process. Summary of the invention

[0010] In view of this, the purpose of the embodiments of the present invention is to provide a method for preparing high-purity vanadium pentoxide, which solves the technical problems of low yield and high cost in the existing high-purity vanadium pentoxide preparation process.

[0011] Based on the above purpose, the embodiment of the present invention provides a method for preparing high-purity vanadium pentoxide, comprising: S1, adding calcium chloride solution and aluminum sulfate to the vanadium-containing leaching solution, stirring, standing and filtering to obtain a vanadium-containing purified solution; S2, adjusting the pH value of the vanadium-containing purified liquid obtained in step S1 to 2-3, heating the temperature to 60-80° C., adding ammonium sulfate, stirring and reacting the solution while it is boiling, and obtaining ammonium polyvanadate after solid-liquid separation; S3, adding water to the ammonium polyvanadate obtained in step S2 to make a slurry for washing, filtering, and drying until the moisture content is less than 1%; S4, adding the ammonium polyvanadate washed in step S3 into an electric rotary kiln for deammoniation and calcination.

[0012] According to one embodiment of the present invention, in step S1, the vanadium-containing leaching solution comes from the solution leached after sodium roasting, and its main components are, by mass percentage, vanadium 30-45 g / L, phosphorus ≤0.2 g / L, silicon 1.0-2.0 g / L, and the pH value of the vanadium-containing leaching solution is 9-13.

[0013] According to one embodiment of the present invention, in step S1, the concentration of the calcium chloride solution is 12% to 16%, and the volume ratio of the added calcium chloride solution is 0.6% to 0.8%.

[0014] According to one embodiment of the present invention, in step S1, the mass ratio of aluminum sulfate added is m(Al2(SO4)3) / m(Si) is 5-10.

[0015] According to one embodiment of the present invention, in step S1, the stirring time is ≥2h, and the standing time is ≥48h.

[0016] According to one embodiment of the present invention, in step S2, the amount of ammonium sulfate added is determined by the mass ratio of ammonium sulfate to vanadium in the solution, and the ammonium addition coefficient is 1.0-1.5.

[0017] According to one embodiment of the present invention, in step S3, the water is production water, the liquid-to-solid ratio of pulping and washing is 0.3-0.6 mL / g, and the temperature of the washing water is 70-90°C.

[0018] According to an embodiment of the present invention, in step S3, the drying temperature is 90-120°C.

[0019] According to one embodiment of the present invention, in step S4, the feeding frequency of adding ammonium polyvanadate into the electric rotary kiln is 6-12 Hz, the drum speed frequency is 22-25 Hz, and the negative pressure in the kiln is -16--10 Pa.

[0020] According to one embodiment of the present invention, in step S4, the calcination temperature is 580-590°C.

[0021] The present invention has at least the following beneficial technical effects: The invention adopts sodium-treated leaching solution, removes phosphorus and desilicon from the leaching solution, and then uses acidic ammonium salt to precipitate vanadium to obtain ammonium polyvanadate. The high-purity powder obtained by drying and calcining the ammonium polyvanadate is converted into vanadium pentoxide, thereby avoiding the problems of low vanadium precipitation efficiency, large ammonium salt consumption, high residual vanadium concentration in wastewater, difficulty in wastewater treatment and high production cost in the preparation process of high-purity vanadium pentoxide. The invention provides a method for preparing high-purity vanadium pentoxide at low cost, capable of controlling the vanadium content to be ≥99% and the low-price vanadium to be controlled within ≤1.5%. DETAILED DESCRIPTION

[0022] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the embodiments of the present invention are further described in detail below in conjunction with specific embodiments.

[0024] In addition, reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present invention. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0025] The present invention provides a method for preparing high-purity vanadium pentoxide, comprising the following steps: S1, adding calcium chloride solution and aluminum sulfate to the vanadium-containing leaching solution, stirring, standing and filtering to obtain a vanadium-containing purified solution; S2, adjusting the pH value of the vanadium-containing purified liquid obtained in step S1 to 2-3, heating the temperature to 60-80° C., adding ammonium sulfate, stirring and reacting the solution while it is boiling, and obtaining ammonium polyvanadate after solid-liquid separation; S3, adding water to the ammonium polyvanadate obtained in step S2 to make a slurry for washing, filtering, and drying until the moisture content is less than 1%; S4, adding the ammonium polyvanadate washed in step S3 into an electric rotary kiln for deammoniation and calcination.

[0026] In some embodiments, in step S1, the vanadium-containing leachate is from the leachate after sodium roasting. By adding calcium chloride and aluminum sulfate to the sodium vanadium-containing leachate, impurities such as phosphorus and silicon in the vanadium-containing leachate can be efficiently removed, the purity of the vanadium-containing purified liquid can be significantly improved, and the interference of impurities on subsequent vanadium precipitation can be reduced. After static filtration, the impurities are completely separated, the loss rate of vanadium in the vanadium-containing purified liquid is low, and the extraction rate is higher than the existing process. In step S2, the pH value is adjusted to 2-3 and the solution is heated to 60-80°C to provide the best reaction conditions for ammonium sulfate vanadium precipitation, ensuring that vanadium is efficiently precipitated in the form of ammonium polyvanadate. The stirring reaction is carried out in a boiling state of the solution to improve the reaction efficiency and vanadium precipitation efficiency. It avoids the use of alkaline ammonium salt to precipitate vanadium to obtain ammonium metavanadate, resulting in low vanadium precipitation efficiency, large ammonium salt consumption, high residual vanadium concentration in wastewater, difficult wastewater treatment, and high production cost in the preparation process of high-purity vanadium pentoxide. In step S3, water slurry is used during the washing process of ammonium polyvanadate to effectively remove the attached soluble impurities, ensuring a higher product purity. In step S4, an electric rotary kiln is used to deaminate and calcine the ammonium polyvanadate, which can stably control the calcination temperature and atmosphere to ensure the high purity and high quality of vanadium pentoxide. The electric rotary kiln has high thermal efficiency, a thorough deammoniation process, reduced ammonia emissions, and reduced environmental pollution and post-processing difficulty.

[0027] The high-purity powder obtained by the above steps of the present invention is converted into vanadium pentoxide, and the vanadium content is controlled to be ≥99%, and the low-price vanadium is controlled to be within ≤1.5%. It can significantly improve the extraction efficiency and product purity of vanadium, reduce energy consumption and environmental pollution, reduce production costs, and has both high efficiency and environmental protection, and is suitable for industrial-scale Gaochun vanadium pentoxide production.

[0028] In some embodiments, in step S1, the vanadium-containing leaching solution comes from the solution leached after sodium roasting, and its main components, in terms of mass percentage, are: vanadium 30-45 g / L, phosphorus ≤0.2 g / L, silicon 1.0-2.0 g / L, and the pH value of the vanadium-containing leaching solution is 9-13.

[0029] In some embodiments, in step S1, the concentration of the calcium chloride solution is 12% to 16%, and the volume ratio of the added calcium chloride solution is 0.6% to 0.8%.

[0030] In some embodiments, in step S1, the mass ratio of aluminum sulfate added is m(Al2(SO4)3) / m(Si) is 5~10.

[0031] In some embodiments, in step S1, the stirring time is ≥2 h, and the standing time is ≥48 h.

[0032] In some embodiments, in step S2, the amount of ammonium sulfate added is determined by the ratio of the mass of ammonium sulfate to the mass of vanadium in the solution, and the ammonium addition coefficient is 1.0 to 1.5. Further, the amount of ammonium sulfate added is determined by comparing with the mass of vanadium in the solution, for example, when the ammonium addition coefficient is 1.0, the amount of ammonium sulfate added is equal to the mass of vanadium in the solution, and when the ammonium addition coefficient is 1.5, the amount of ammonium sulfate added is 1.5 times the mass of vanadium in the solution. According to process requirements, the amount of ammonium sulfate added can be adjusted between 1 and 1.5 times the mass of vanadium in the solution to achieve the best reaction effect and vanadium precipitation efficiency.

[0033] In some embodiments, in step S3, the water is production water, the liquid-to-solid ratio of slurry washing is 0.3-0.6 mL / g, and the temperature of the washing water is 70-90°C.

[0034] In some embodiments, in step S3, the drying temperature is 90-120°C.

[0035] In some embodiments, in step S4, the feeding frequency of adding ammonium polyvanadate to the electric rotary kiln is 6-12 Hz, the drum speed frequency is 22-25 Hz, and the negative pressure in the kiln is -16--10 Pa.

[0036] In some embodiments, in step S4, the calcination temperature is 580-590°C.

[0037] The invention adopts sodium-treated leaching solution, removes phosphorus and desilicon from the leaching solution, and then uses acidic ammonium salt to precipitate vanadium to obtain ammonium polyvanadate. The high-purity powder obtained by drying and calcining the ammonium polyvanadate is converted into vanadium pentoxide, thereby avoiding the problems of low vanadium precipitation efficiency, large ammonium salt consumption, high residual vanadium concentration in wastewater, difficulty in wastewater treatment and high production cost in the preparation process of high-purity vanadium pentoxide. The invention provides a method for preparing high-purity vanadium pentoxide at low cost, capable of controlling the vanadium content to be ≥99% and the low-price vanadium to be controlled within ≤1.5%.

[0038] The present invention is further explained below in conjunction with specific embodiments and comparative examples.

[0039] Example 1 A 15% calcium chloride solution and aluminum sulfate at a volume ratio of 0.8% and a m(Al2(SO4)3) / m(Si) of 6 were added to the vanadium-containing leaching solution, and the mixture was stirred for 2 hours. After standing for 48 hours, the mixture was filtered to obtain a vanadium-containing purified solution. The pH value of the purified solution was adjusted to 2.0, the temperature was heated to 70°C, ammonium sulfate was added at an ammonium addition coefficient of 1.0, and the solution was stirred for reaction for 40 minutes under boiling conditions, and ammonium polyvanadate was obtained by solid-liquid separation. The prepared ammonium polyvanadate was added with 85°C production water at a liquid-to-solid ratio of 0.6L / kg for pulping, washing and filtration, and the filtered ammonium polyvanadate was passed into a flash drying process and dried at a temperature of 100°C. Finally, ammonium polyvanadate is added into the rotary kiln at a feeding frequency of 10 Hz, the drum speed frequency of the rotary kiln is controlled to be 22 Hz, and the negative pressure in the kiln is -16~-10 Pa for calcination. The composition of the high-purity vanadium pentoxide produced is as follows, in terms of mass percentage: V2O5: 99.33%, Si: 0.061%, P: 0.004%, S: 0.077%; K2O: 0.08%, Na2O: 0.226%, Fe: 0.025%, As: 0.005%, V2O4: 1.37%, Cr: 0.049%, Al: 0.011%, Ca: 0.018%.

[0040] Example 2 A 15% calcium chloride solution and aluminum sulfate at a concentration of 8 at a volume ratio of 0.8% are added to the vanadium-containing leaching solution, and the mixture is stirred for 2 hours. After standing for 48 hours, the mixture is filtered to obtain a vanadium-containing purified solution. The pH value of the purified solution is adjusted to 2.5, the temperature is heated to 70°C, ammonium sulfate is added at an ammonium addition coefficient of 1.0, and the solution is stirred for reaction for 40 minutes under boiling conditions, and ammonium polyvanadate is obtained by solid-liquid separation. The prepared ammonium polyvanadate is added with 85°C production water at a liquid-to-solid ratio of 0.6L / kg for pulping, washing and filtration, and the filtered ammonium polyvanadate is passed into a flash drying process and dried at a temperature of 100°C. Finally, ammonium polyvanadate was added into the rotary kiln at a feeding frequency of 6 Hz, the drum speed of the rotary kiln was controlled to be 22 Hz, and the negative pressure in the kiln was -16~-10 Pa for calcination. The components of the high-purity vanadium pentoxide produced were as follows, in terms of mass percentage: V2O5: 99.13%, Si: 0.035%, P: 0.004%, S: 0.09%; K2O: 0.228%, Na2O: 0.0.309%, Fe: 0.013%, As: 0.003%, V2O4: 0.87%, Cr: 0.054%, Al: 0.001%, Ca: 0.003%.

[0041] Example 3 A 15% calcium chloride solution and aluminum sulfate at a volume ratio of 0.8% and a m(Al2(SO4)3) / m(Si) ratio of 10 were added to the vanadium-containing leaching solution, and the mixture was stirred for 2 hours. After standing for 48 hours, the mixture was filtered to obtain a vanadium-containing purified solution. The pH value of the purified solution was adjusted to 2-3, the temperature was heated to 70°C, and ammonium sulfate was added at an ammonium addition coefficient of 1.5. The solution was stirred and reacted for 40 minutes under boiling conditions, and ammonium polyvanadate was obtained by solid-liquid separation. The prepared ammonium polyvanadate was pulped, washed and filtered by adding 85°C production water at a liquid-solid ratio of 0.6L / kg. The filtered ammonium polyvanadate was passed into a flash drying process and dried at a temperature of 100°C. Finally, ammonium polyvanadate is added into the rotary kiln at a feeding frequency of 8 Hz, the drum speed frequency of the rotary kiln is controlled to be 22 Hz, and the negative pressure in the kiln is -16~-10 Pa for calcination. The composition of the high-purity vanadium pentoxide produced is as follows, in terms of mass percentage: V2O5: 99.13%, Si: 0.016%, P: 0.004%, S: 0.066%; K2O: 0.22%, Na2O: 0.37%, Fe: 0.013%, As: 0.003%, V2O4: 0.1.18%, Cr: 0.051%, Al: 0.001%, Ca: 0.003%.

[0042] Example 4 A 15% calcium chloride solution and aluminum sulfate at a concentration of 10 were added to the vanadium-containing leaching solution at a volume ratio of 0.8%, and the mixture was stirred for 2 hours. After standing for 48 hours, the mixture was filtered to obtain a vanadium-containing purified solution. The pH value of the purified solution was adjusted to 2-3, the temperature was heated to 70°C, ammonium sulfate was added at an ammonium addition coefficient of 1.5, and the solution was stirred for 40 minutes under boiling conditions, and ammonium polyvanadate was obtained by solid-liquid separation. The prepared ammonium polyvanadate was added with 85°C production water at a liquid-to-solid ratio of 0.6L / kg for pulping, washing and filtration, and the filtered ammonium polyvanadate was The mixture is flash dried at 100°C, and finally ammonium polyvanadate is added into the rotary kiln at a feeding frequency of 10 Hz. The drum speed of the rotary kiln is controlled to be 25 Hz, and the negative pressure in the kiln is -16 to -10 Pa for calcination. The components of the high-purity vanadium pentoxide produced are as follows: V2O5: 99.11%, Si: 0.02%, P: 0.003%, S: 0.063%; K2O: 0.25%, Na2O: 0.418%, Fe: 0.01%, As: 0.003%, V2O 4： 0.1.30%, Cr: 0.057%, Al: 0.001%, Ca: 0.003%.

[0043] The above are exemplary embodiments disclosed in the present invention, but it should be noted that various changes and modifications may be made without departing from the scope disclosed in the embodiments of the present invention as defined in the claims. The functions, steps and / or actions of the method claims according to the disclosed embodiments described herein do not need to be performed in any particular order. In addition, although the elements disclosed in the embodiments of the present invention may be described or required in individual form, they may also be understood as multiple unless explicitly limited to the singular.

[0044] It should be understood that, as used herein, the singular forms "a", "an" are intended to include the plural forms as well, unless the context clearly supports an exception. It should also be understood that, as used herein, "and / or" refers to any and all possible combinations including one or more of the associated listed items.

[0045] The serial numbers of the embodiments disclosed in the above embodiments of the present invention are only for description and do not represent the advantages or disadvantages of the embodiments.

[0046] A person skilled in the art should understand that the discussion of any of the above embodiments is only exemplary and is not intended to imply that the scope of the disclosure of the embodiments of the present invention (including the claims) is limited to these examples; under the concept of the embodiments of the present invention, the technical features in the above embodiments or different embodiments can also be combined, and there are many other changes in different aspects of the above embodiments of the present invention, which are not provided in detail for the sake of simplicity. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the embodiments of the present invention should be included in the protection scope of the embodiments of the present invention.

Claims

1. A method for preparing high-purity vanadium pentoxide, characterized in that: include: S1, adding calcium chloride solution and aluminum sulfate to the vanadium-containing leaching solution, stirring, standing and filtering to obtain a vanadium-containing purified solution; S2, adjusting the pH value of the vanadium-containing purified liquid obtained in step S1 to 2-3, heating the temperature to 60-80° C., adding ammonium sulfate, stirring and reacting the solution while it is boiling, and obtaining ammonium polyvanadate after solid-liquid separation; S3, adding water to the ammonium polyvanadate obtained in step S2 to make a slurry for washing, filtering, and drying until the moisture content is less than 1%; S4, adding the ammonium polyvanadate washed in step S3 into an electric rotary kiln for deammoniation and calcination.

2. The method according to claim 1, characterized in that In step S1, the vanadium-containing leaching solution comes from the solution leached after sodium roasting, and its main components are, by mass percentage, vanadium 30-45 g / L, phosphorus ≤0.2 g / L, silicon 1.0-2.0 g / L, and the pH value of the vanadium-containing leaching solution is 9-13.

3. The method according to claim 1, characterized in that In step S1, the concentration of the calcium chloride solution is 12% to 16%, and the volume ratio of the added calcium chloride solution is 0.6% to 0.8%.

4. The method according to claim 1, characterized in that: In step S1, the mass ratio of aluminum sulfate added is m(Al2(SO4)3) / m(Si) is 5~10.

5. The method according to claim 1, characterized in that In step S1, the stirring time is ≥2 h, and the standing time is ≥48 h.

6. The method according to claim 1, characterized in that In step S2, the amount of ammonium sulfate added is determined by the mass ratio of ammonium sulfate to vanadium in the solution, and the ammonium addition coefficient is 1.0-1.

5.

7. The method according to claim 1, characterized in that In step S3, the water is production water, the liquid-solid ratio of pulping and washing is 0.3-0.6 mL / g, and the temperature of the washing water is 70-90°C.

8. The method according to claim 1, characterized in that In step S3, the drying temperature is 90-120°C.

9. The method according to claim 1, characterized in that: In step S4, the feeding frequency of adding ammonium polyvanadate into the electric rotary kiln is 6-12 Hz, the drum speed frequency is 22-25 Hz, and the negative pressure in the kiln is -16--10 Pa.

10. The method according to claim 1, characterized in that In step S4, the calcination temperature is 580-590°C.