Method for preparing vanadium trioxide by using vanadium-rich solution
By reducing the vanadium-rich solution by phosphite, adjusting the pH value and stirring the reaction, the environmental pollution and complex operation problems in the ammonium vanadium depositing process are solved, and the preparation of high-purity vanadium trioxide is achieved. The process is simple and the cost is low. The reaction is Fast rate, product purity exceeds 99%.
Patent Information
- Application Number
- CN202411394318.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-08
- Publication Date
- 2024-12-31
AI Technical Summary
During the existing vanadium extraction process, the ammonium salt vanadium precipitation process has problems such as environmental pollution, complex operation and impurity of products, and traditional liquid phase hydrogen reduction technology requires expensive catalysts and strict conditions.
Use phosphite to reduce vanadium-rich solution, adjust the pH value to 7~12, and generate vanadium trioxide, avoid expensive catalysts and high-temperature pressurization, and obtain high-purity vanadium trioxide through stirring reaction, solid-liquid separation, washing and drying. .
The preparation of high-purity vanadium trioxide is achieved, with simple process, low cost and fast reaction rate, avoiding environmental pollution and the use of expensive catalysts, and the product purity exceeds 99%.
Smart Images
Figure CN119219058A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of hydrometallurgy, and in particular relates to a method for preparing vanadium trioxide by utilizing a vanadium-rich solution. Background Art
[0002] In the process of vanadium extraction, vanadium precipitation is an indispensable process. Currently, there are hydrolysis vanadium precipitation, calcium salt vanadium precipitation, iron salt vanadium precipitation and ammonium salt vanadium precipitation. Hydrolysis vanadium precipitation has problems such as low precipitation rate and low product purity. This process is only used in the early stage of vanadium extraction. Calcium salt vanadium precipitation and iron salt vanadium precipitation are greatly affected by raw materials and have a narrow range of applications. Among them, ammonium salt vanadium precipitation is the most widely used method at present. In the prior art, ammonium salt vanadium precipitation to prepare V2O5 involves two processes: in the first stage, ammonium salt is used to precipitate vanadium in vanadium solution to obtain ammonium vanadate solid; in the second stage, the ammonium vanadate solid is calcined to obtain V2O5 product. However, ammonium salt vanadium precipitation has environmental problems that cannot be ignored. On the one hand, the ammonia nitrogen concentration in the vanadium precipitation wastewater is seriously exceeded, and the tail water treatment and reuse are difficult; on the other hand, acidic ammonium salt vanadium precipitation also requires a subsequent calcination process, and the ammonia generated during the calcination process also has potential air pollution problems. Moreover, the above-mentioned vanadium precipitation method usually produces V2O5, not V2O3. The liquid-phase hydrogen reduction technology in the prior art is a green and environmentally friendly vanadium precipitation method that can obtain V2O3, but the reaction process requires the addition of expensive catalysts (such as PdCl2, etc.), and the process conditions need to be strictly controlled and the operation is difficult. Summary of the invention
[0003] In order to overcome the problems in the prior art, the present invention provides a method for preparing vanadium trioxide using a vanadium-rich solution. The vanadium trioxide is prepared by precipitating the vanadium-rich solution using phosphite without using an expensive catalyst. The product of the present invention has high purity, simple and easy operation, fast precipitation rate and low production cost.
[0004] In order to solve the above technical problems, the technical solution proposed by the present invention is: The present invention provides a method for preparing vanadium trioxide by using a vanadium-rich solution, comprising the following steps: The pH of the vanadium-rich solution is adjusted to 7-12, and then phosphite is added and stirred for reaction. After the reaction is completed, solid-liquid separation, washing, and drying are performed to obtain vanadium trioxide.
[0005] In the present invention, after the pH of the vanadium-rich solution is adjusted to 7-12 required for the reaction, phosphite is added to reduce the tetravalent vanadium and / or pentavalent vanadium in the solution to trivalent vanadium to generate vanadium trioxide.
[0006] As an optional embodiment, in the method provided by the present invention, the vanadium-rich solution is a solution containing tetravalent vanadium and / or pentavalent vanadium.
[0007] As an optional implementation, in the method provided by the present invention, the pH of the vanadium-rich solution is adjusted to 10-11.
[0008] As an optional embodiment, in the method provided by the present invention, the molar ratio of the phosphite to the vanadium in the vanadium-rich liquid is 0.5-2.
[0009] In the present invention, the molar ratio of phosphite to vanadium in vanadium-rich liquid is controlled to be 0.5-2 to ensure the optimal amount of phosphite as a reducing agent; exceeding this range will not produce additional beneficial effects, and will cause waste of reagents and increase costs.
[0010] As an optional embodiment, in the method provided by the present invention, the phosphite is an inorganic phosphite.
[0011] Compared with organic phosphites, the inorganic phosphites selected in the present invention have stronger reducing properties.
[0012] As an optional embodiment, in the method provided by the present invention, the phosphite is selected from one or both of sodium phosphite and potassium phosphite.
[0013] As an optional embodiment, in the method provided by the present invention, the stirring speed during the reaction is 100-400 rpm, and the reaction time is 0.5-3 h.
[0014] As an optional embodiment, in the method provided by the present invention, sodium hydroxide or sulfuric acid solution is used to adjust the pH of the vanadium-rich solution.
[0015] Compared with the prior art, the present invention has the following beneficial effects: Compared with the traditional method of using reducing gases such as hydrogen as reducing agents, the present invention uses phosphite as a reducing agent, which has high reactivity, fast reaction rate and short time. The reaction product of phosphite is hydrogen phosphate, which can buffer the pH of the system. Compared with the traditional ammonium salt precipitation of vanadium, the present invention only requires one stage of reduction precipitation, the process flow is simple and easy to operate, and V2O3 can be prepared without the use of pressure, high temperature and other measures. In addition, the present invention has low production cost, and the reaction process does not require the addition of expensive catalysts to accelerate the reaction. After solid-liquid separation, washing and drying of the precipitated product, a high-purity vanadium trioxide product (purity> 99%) can be obtained. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.
[0017] Figure 1 It is a process flow chart of the present invention. DETAILED DESCRIPTION
[0018] In order to facilitate the understanding of the present invention, the present invention will be described more comprehensively and meticulously below in conjunction with the accompanying drawings and preferred embodiments of the present invention, but the protection scope of the present invention is not limited to the following specific embodiments.
[0019] Unless otherwise defined, all professional terms used below have the same meanings as those generally understood by those skilled in the art. The professional terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the scope of protection of the present invention.
[0020] Unless otherwise specified, various raw materials, reagents, instruments and equipment used in the present invention can be purchased from the market or prepared by existing methods.
[0021] Example 1 A method for preparing vanadium trioxide using a vanadium-rich solution, such as Figure 1 As shown, the following steps are included: The vanadium content of the vanadium-rich solution used is 1 mol / L, of which V(IV) accounts for 100%.
[0022] The pH value of the vanadium-rich solution is adjusted to 8 using sodium hydroxide or sulfuric acid solution, 0.5 mol / L sodium phosphite is added, the stirring speed is 300 rpm, the reaction time is 2 h, and after the reaction is completed, solid-liquid separation, washing, and drying are performed to obtain vanadium trioxide.
[0023] The experimental results are: the vanadium precipitation rate is 93.52% and the purity of vanadium trioxide is 97.18%.
[0024] Example 2 The vanadium content of the vanadium-rich solution used is 1 mol / L, of which V(IV) accounts for 100%.
[0025] The pH value of the vanadium-rich solution is adjusted to 9 using sodium hydroxide or sulfuric acid solution, 0.5 mol / L sodium phosphite is added, the stirring speed is 300 rpm, the reaction time is 2 h, and after the reaction is completed, solid-liquid separation, washing, and drying are performed to obtain vanadium trioxide.
[0026] The experimental results are: the vanadium precipitation rate is 95.27% and the purity of vanadium trioxide is 98.25%.
[0027] Example 3 The vanadium content of the vanadium-rich solution used is 1 mol / L, of which V(IV) accounts for 100%.
[0028] The pH value of the vanadium-rich solution is adjusted to 10 using sodium hydroxide or sulfuric acid solution, 0.5 mol / L sodium phosphite is added, the stirring speed is 300 rpm, the reaction time is 2 h, and after the reaction is completed, solid-liquid separation, washing, and drying are performed to obtain vanadium trioxide.
[0029] The experimental results are: the vanadium precipitation rate is 97.26%, and the purity of vanadium trioxide is 99.13%.
[0030] Example 4 The vanadium content of the vanadium-rich solution used is 1 mol / L, of which V(IV) accounts for 100%.
[0031] The pH value of the vanadium-rich solution is adjusted to 10 using sodium hydroxide or sulfuric acid solution, 0.5 mol / L sodium phosphite is added, the stirring speed is 400 rpm, the reaction time is 2 h, and after the reaction is completed, solid-liquid separation, washing, and drying are performed to obtain vanadium trioxide.
[0032] The experimental results are: the vanadium precipitation rate is 97.88% and the purity of vanadium trioxide is 99.16%.
[0033] Example 5 The vanadium content of the vanadium-rich solution used is 1 mol / L, of which V(IV) accounts for 100%.
[0034] The pH value of the vanadium-rich solution is adjusted to 10 using sodium hydroxide or sulfuric acid solution, 0.5 mol / L sodium phosphite is added, the stirring speed is 300 rpm, the reaction time is 3 h, and after the reaction is completed, solid-liquid separation, washing, and drying are performed to obtain vanadium trioxide.
[0035] The experimental results are: the vanadium precipitation rate is 97.76% and the purity of vanadium trioxide is 99.15%.
[0036] Example 6 The vanadium content of the vanadium-rich solution used is 1 mol / L, of which V(IV) accounts for 100%.
[0037] The pH value of the vanadium-rich solution is adjusted to 11 using sodium hydroxide or sulfuric acid solution, 0.5 mol / L sodium phosphite is added, the stirring speed is 300 rpm, the reaction time is 2 h, and after the reaction is completed, solid-liquid separation, washing, and drying are performed to obtain vanadium trioxide.
[0038] The experimental results are: the vanadium precipitation rate is 96.24% and the purity of vanadium trioxide is 99.06%.
[0039] Example 7 The vanadium content of the vanadium-rich solution used is 1 mol / L, of which V(IV) accounts for 100%.
[0040] The pH value of the vanadium-rich solution is adjusted to 10 using sodium hydroxide or sulfuric acid solution, and 0.75 mol / L sodium phosphite is added. The stirring speed is 300 rpm and the reaction time is 2 h. After the reaction is completed, solid-liquid separation, washing and drying are performed to obtain vanadium trioxide.
[0041] The experimental results are: the vanadium precipitation rate is 99.35%, and the purity of vanadium trioxide is 99.25%.
[0042] Example 8 The vanadium content of the vanadium-rich solution used is 1 mol / L, of which V(IV) accounts for 100%.
[0043] The pH value of the vanadium-rich solution is adjusted to 10 using sodium hydroxide or sulfuric acid solution, 1 mol / L sodium phosphite is added, the stirring speed is 300 rpm, the reaction time is 2 h, and after the reaction is completed, solid-liquid separation, washing, and drying are performed to obtain vanadium trioxide.
[0044] The experimental results are: the vanadium precipitation rate is 99.46% and the purity of vanadium trioxide is 99.34%.
[0045] Example 9 The V content in the vanadium-rich solution used is 1 mol / L, of which V (V) accounts for 100%.
[0046] The pH value of the vanadium-rich solution is adjusted to 10 using sodium hydroxide or sulfuric acid solution, 2 mol / L sodium phosphite is added, the stirring speed is 300 rpm, the reaction time is 2 h, and after the reaction is completed, solid-liquid separation, washing, and drying are performed to obtain vanadium trioxide.
[0047] The experimental results are: the vanadium precipitation rate is 99.42% and the purity of vanadium trioxide is 99.31%.
[0048] Example 10 The V content in the vanadium-rich solution used is 1 mol / L, of which V(IV) accounts for 50% and V(V) accounts for 50%.
[0049] The pH value of the vanadium-rich solution is adjusted to 10 using sodium hydroxide or sulfuric acid solution, 2 mol / L sodium phosphite is added, the stirring speed is 300 rpm, the reaction time is 2 h, and after the reaction is completed, solid-liquid separation, washing, and drying are performed to obtain vanadium trioxide.
[0050] The experimental results are: the vanadium precipitation rate is 99.48% and the purity of vanadium trioxide is 99.35%.
[0051] The above contents are further detailed descriptions of the present invention in combination with specific preferred embodiments, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. For ordinary technicians in the field to which the present invention belongs, several simple deductions or substitutions can be made without departing from the concept of the present invention, which should be regarded as falling within the scope of protection of the present invention.
Claims
1. A method for preparing vanadium trioxide using a vanadium-rich solution, characterized in that: The following steps are involved: The pH of the vanadium-rich solution is adjusted to 7-12, and then phosphite is added and stirred for reaction. After the reaction is completed, solid-liquid separation, washing, and drying are performed to obtain vanadium trioxide.
2. The method for preparing vanadium trioxide using a vanadium-rich solution according to claim 1, characterized in that: The vanadium-rich solution is a solution containing tetravalent vanadium and / or pentavalent vanadium.
3. The method for preparing vanadium trioxide using a vanadium-rich solution according to claim 1, characterized in that: Adjust the pH of the vanadium-rich solution to 10-11.
4. The method for preparing vanadium trioxide using a vanadium-rich solution according to claim 1, characterized in that: The molar ratio of the phosphite to the vanadium in the vanadium-rich solution is 0.5-2.
5. The method for preparing vanadium trioxide using vanadium-rich solution according to claim 1, characterized in that: The phosphite is an inorganic phosphite.
6. The method for preparing vanadium trioxide using a vanadium-rich solution according to any one of claims 1 to 5, characterized in that: The phosphite is selected from one or both of sodium phosphite and potassium phosphite.
7. The method for preparing vanadium trioxide using a vanadium-rich solution according to claim 1, characterized in that: The stirring speed during the reaction is 100~400 rpm, and the reaction time is 0.5~3 h.
8. The method for preparing vanadium trioxide using vanadium-rich solution according to claim 1, characterized in that: Sodium hydroxide or sulfuric acid solution is used to adjust the pH of the vanadium-rich solution.