A method for preparing vanadium trioxide
By using sodium vanadate to reduce sodium vanadate with sodium succinate in a one-step process, vanadium trioxide is prepared, which solves the problems of lengthy process, high energy consumption and wastewater pollution in the existing technology. It achieves the preparation of vanadium trioxide with high purity and high yield, which is suitable for large-scale industrial production.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- 北京绿钒新能源科技有限公司
- Filing Date
- 2023-12-15
- Publication Date
- 2026-05-15
AI Technical Summary
Existing methods for preparing vanadium trioxide are lengthy, energy-intensive, have low automation, high operating costs, and pose wastewater pollution and hazards. In particular, the reduction process of vanadium pentoxide, which uses reducing gases such as H2 and CO, is highly dangerous.
Using sodium formaldehyde sulfoxylate (CH6Na2O5S) as a reducing agent, sodium vanadate is directly reduced, replacing traditional reducing gases such as H2 and CO. Vanadium trioxide is prepared in a one-step process of roasting, washing and drying, which simplifies the process and reduces energy consumption.
A low-cost, safe, and environmentally friendly method for preparing vanadium trioxide has been achieved, with a product purity of over 99.5% and a yield of up to 99%, making it suitable for large-scale industrial production.
Smart Images
Figure CN117720126B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of chemical material synthesis technology, specifically relating to a method for preparing vanadium trioxide. Background Technology
[0002] Currently, the preparation method of vanadium trioxide involves sodium roasting of vanadium slag, leaching, ammonium salt precipitation of vanadium, calcination to obtain vanadium pentoxide, and reduction of vanadium pentoxide to obtain vanadium trioxide. While this technology is relatively mature and widely used, it suffers from a lengthy process, high energy consumption, low automation, and high operating costs, and generates a large amount of wastewater during production. Furthermore, the reduction of vanadium pentoxide typically uses reducing gases such as H2 and CO, making the production process quite hazardous.
[0003] To address the above problems, this invention is proposed. Summary of the Invention
[0004] This invention provides a method for preparing vanadium trioxide, the method comprising the following steps:
[0005] (1) Sodium vanadate and sculpting powder are mixed and ball-milled to obtain a mixture powder;
[0006] (2) The mixture powder is calcined at 350-500 degrees Celsius for 2-4 hours under a nitrogen atmosphere to obtain calcined cooked material;
[0007] (3) The roasted clinker is washed and dried to obtain the final product vanadium trioxide.
[0008] Preferably, the washing process involves adding water to the roasted calcined material, raising the water temperature to 80-100°C, stirring for 1-2 hours to ensure thorough mixing and dissolution, then filtering and extracting the filter cake.
[0009] Preferably, the sodium vanadate salt is at least one of sodium metavanadate, sodium orthovanadate, sodium pyrovanadate, and sodium tetravanadate.
[0010] Preferably, the drying temperature is 60 to 120 degrees Celsius.
[0011] Preferably, the drying time is 1 to 2 hours.
[0012] Preferably, in step (1), the molar ratio of sodium vanadate to sodium chloroform is 1:1 to 1:4.
[0013] Compared with the prior art, the present invention has the following beneficial effects:
[0014] 1. This invention uses sodium formaldehyde sulfoxylate (CH6Na2O5S) as a reducing agent to directly reduce sodium vanadate, effectively replacing the reducing gases such as H2 and CO in the traditional vanadium trioxide preparation process, thus eliminating the hazards associated with using reducing gases as reducing agents. Furthermore, the method of this application eliminates the ammonium salt precipitation process of the traditional process, greatly simplifying the entire vanadium trioxide preparation process. The amount of wastewater generated during material preparation is also significantly reduced. This process features a short flow rate, low material costs, low operating costs, and environmental friendliness, making it suitable for large-scale industrial production.
[0015] 2. This application obtains the final product through reduction with sodium vanadate, rather than reduction with ammonium vanadate. Therefore, no toxic ammonia gas is generated during the reaction, thus avoiding environmental pollution.
[0016] 3. This application unexpectedly discovered that succulent has extremely strong reducing properties and a high reduction rate. Compared with the reduction of ammonium vanadate by oxalic acid, it can reduce the reaction temperature by about 100 degrees Celsius, which greatly reduces energy consumption.
[0017] 4. The reducing agent of this invention is inexpensive and readily available.
[0018] 5. In particular, the inventive point of this application lies in the fact that the conventional technical means of preparing vanadium trioxide using sodium roasting of vanadium slag followed by leaching and ammonium salt precipitation to obtain ammonium polyvanadate is an indispensable step. This application directly uses the sodium vanadate obtained from sodium roasting of vanadium slag as a raw material and reduces it with sodium silicate in one step to obtain vanadium trioxide. Those skilled in the art typically use ammonium vanadate as a raw material for direct pyrolysis or reduction (e.g., gaseous products such as ammonia can be directly removed) to maintain the purity of the product, and have never considered directly reducing the sodium vanadate obtained from sodium roasting of vanadium slag.
[0019] 6. Furthermore, since the purity of raw materials such as vanadium pentoxide, ammonium polyvanadate, and ammonium metavanadate is generally between 98% and 99%, the impurities cannot be removed by calcination. Therefore, after calcination and reduction, the purity of the vanadium trioxide product obtained by traditional processes will not exceed 99% due to the lack of subsequent impurity removal processes. In contrast, this invention uses sodium vanadate as a raw material. Due to the strong reducing properties of sodium carbonate, it directly reduces sodium vanadate to vanadium trioxide and soluble impurities during the reaction. After reduction by sodium carbonate and subsequent washing with water, the resulting impurities are soluble sodium salts (sodium sulfate, sodium carbonate, and sodium bicarbonate, etc.), all of which are soluble in water and can be largely removed by filtration, resulting in a vanadium trioxide product with a purity of over 99.5%.
[0020] 7. This application also has the unexpected effect of producing vanadium trioxide with a yield of over 99%. Attached Figure Description
[0021] Figure 1 This is a SEM image of the vanadium trioxide powder prepared in Example 1.
[0022] Figure 2 This is the XRD pattern of the vanadium trioxide powder prepared in Example 1. Detailed Implementation
[0023] The present invention will be described below with reference to specific embodiments, but the implementation of the present invention is not limited thereto. Experimental methods not specifically described in the embodiments generally use conventional conditions and conditions described in the manual, or conditions recommended by the manufacturer. The general equipment, materials, reagents, etc., used are all commercially available unless otherwise specified. The raw materials required in the following embodiments and comparative examples are all commercially available.
[0024] This invention utilizes a highly reducing agent, sodium formaldehyde sulfoxylate (CH6Na2O5S), thoroughly mixed with vanadate. Under high temperature conditions, the sodium formaldehyde sulfoxylate undergoes a reduction reaction with the sodium vanadate to obtain a reduced clinker. The resulting clinker is then dissolved in water to dissolve impurities. The filtered product is dried to obtain vanadium trioxide. This invention eliminates the need for high-temperature decomposition technology and the addition of reducing gases. The reducing agent used is low-cost, the process is simple, safe, and commercially viable, making it suitable for large-scale industrial production.
[0025] The preparation method of sodium vanadate in the following examples and comparative examples is as follows: Sodium vanadate is obtained by sodium roasting of vanadium slag. Specifically, existing technologies can be used, such as adding sodium chloride and / or sodium carbonate to vanadium-containing materials or pre-decarbonized vanadium-containing materials, grinding and mixing them, roasting them, then leaching the roasted material with water, removing impurities from the leachate, and then evaporating and concentrating it to obtain sodium vanadate. By controlling the pH value of the solution, sodium metavanadate and sodium polyvanadates with different degrees of polymerization can be obtained. The purity of both sodium metavanadate and sodium polyvanadates with different degrees of polymerization is above 99%.
[0026] Example 1
[0027] A method for preparing vanadium trioxide:
[0028] 1. Weigh 1 mol of sodium metavanadate (NaVO3) and 1 mol of sodium chloroform in a beaker, mix them thoroughly, and obtain a mixture.
[0029] 2. Then, the obtained mixture is loaded into a stainless steel ball mill jar, and the ball mill jar is placed in a planetary ball mill for ball milling at a speed of 300 rpm for 2 hours to fully mix the two and obtain a mixture powder.
[0030] 3. The obtained mixture powder is placed in a tube furnace with a flowing nitrogen atmosphere (50 ml / min) and calcined at 350°C for 4 hours to obtain calcined clinker, which consists of vanadium trioxide and soluble sodium salt.
[0031] 4. Add water to the roasted clinker and raise the water temperature to 80℃. Stir for 1 hour to ensure thorough mixing and dissolution. Then filter the mixture; soluble sodium salt impurities will dissolve in the filtrate. Extract the vanadium trioxide filter cake.
[0032] 5. The obtained filter cake was dried at 60℃ for 2 hours. After drying, the material was pulverized to obtain the final product, black vanadium trioxide powder, with a flaky structure. ICP-AES analysis showed that the product purity was greater than 99.6%, and the yield of vanadium trioxide was 99.1%. The yield of vanadium trioxide was calculated as: 2n(vanadium trioxide) / n(sodium metavanadate); where n is the amount of substance.
[0033] Example 2
[0034] A method for preparing vanadium trioxide:
[0035] 1. Weigh 1 mol of sodium orthovanadate (Na3VO4) and 1.5 mol of sodium chloroform in a beaker, mix them thoroughly, and obtain a mixture.
[0036] 2. Then, the obtained mixture is loaded into a stainless steel ball mill jar, and the ball mill jar is placed in a planetary ball mill for ball milling at a speed of 300 rpm for 2 hours to fully mix the two and obtain a mixture powder.
[0037] 3. The obtained mixture powder is placed in a tube furnace with a flowing nitrogen atmosphere (50 ml / min) and calcined at 400°C for 3 hours to obtain calcined clinker, which consists of vanadium trioxide and soluble sodium salt.
[0038] 4. Add water to the roasted clinker and raise the water temperature to 80℃. Stir for 1.5 hours to ensure thorough mixing and dissolution. Then filter the mixture; soluble sodium salt impurities will dissolve in the filtrate. Extract the vanadium trioxide filter cake.
[0039] 5. The obtained filter cake was dried at 120℃ for 1 hour. After drying, the material was crushed to obtain the final product, black vanadium trioxide powder, which has a flaky structure. ICP-AES analysis showed that the purity of the product was greater than 99.7% and the yield was 99.3%.
[0040] The yield of vanadium trioxide is calculated as: 2n(vanadium trioxide) / n(sodium orthovanadate); where n is the amount of substance.
[0041] Example 3
[0042] A method for preparing vanadium trioxide:
[0043] 1. Weigh 1 mol of sodium pyrovanadate (Na4V2O7) and 2 mol of sodium chloroform in a beaker, mix them thoroughly, and obtain a mixture.
[0044] 2. Then, the obtained mixture is loaded into a stainless steel ball mill jar, and the ball mill jar is placed in a planetary ball mill for ball milling at a speed of 300 rpm for 2 hours to fully mix the two and obtain a mixture powder.
[0045] 3. The obtained mixture powder is placed in a tube furnace with a flowing nitrogen atmosphere (50 ml / min) and calcined at 450°C for 3 hours to obtain calcined clinker, which consists of vanadium trioxide and soluble sodium salt.
[0046] 4. Add water to the roasted clinker and raise the water temperature to 90℃. Stir for 1.8 hours to ensure thorough mixing and dissolution. Then filter the mixture; soluble sodium salt impurities will dissolve in the filtrate. Extract the vanadium trioxide filter cake.
[0047] 5. The obtained filter cake was dried at 100℃ for 1.5 hours. After drying, the material was pulverized to obtain the final product, black vanadium trioxide powder, with a flaky structure. ICP-AES analysis showed that the product purity was greater than 99.6% and the yield was 99.2%. The yield of vanadium trioxide was calculated as: n(vanadium trioxide) / n(sodium pyrovanadate); where n is the amount of substance.
[0048] Example 4
[0049] A method for preparing vanadium trioxide:
[0050] 1. Weigh 1 mol of sodium tetravanadate (Na₂V₄O₂) into a beaker. 11 ) and 4 mol of white powder, and after mixing them thoroughly, a mixture is obtained.
[0051] 2. Then, the obtained mixture is loaded into a stainless steel ball mill jar, and the ball mill jar is placed in a planetary ball mill for ball milling at a speed of 300 rpm for 2 hours to fully mix the two and obtain a mixture powder.
[0052] 3. The obtained mixture powder is placed in a tube furnace with a flowing nitrogen atmosphere (100 ml / min) and calcined at 500°C for 2 hours to obtain calcined clinker, which consists of vanadium trioxide and soluble sodium salt.
[0053] 4. Add water to the roasted clinker and raise the water temperature to 100℃. Stir for 2 hours to ensure thorough mixing and dissolution. Then filter the mixture; soluble sodium salt impurities will dissolve in the filtrate. Extract the vanadium trioxide filter cake.
[0054] 5. The obtained filter cake was dried at 110℃ for 2 hours. The dried material was then pulverized to obtain the final product, black vanadium trioxide powder, with a flaky structure. ICP-AES analysis showed that the product purity was greater than 99.5%, and the yield was 99.3%. The yield of vanadium trioxide was calculated as: n(vanadium trioxide) / 2n(sodium pyrovanadate); where n is the amount of substance.
[0055] Comparative Example 1
[0056] 20g of sodium vanadate (Na4V2O7) was placed in a ceramic boat and fed into a tube furnace. A mixture of hydrogen and carbon monoxide (volume ratio 1:1) was introduced at a rate of 10ml / min. After reduction at 600℃ for 3 hours, the mixture was continued to be introduced and the furnace cooled to room temperature. The reduction product was washed twice with distilled water and then placed back into the ceramic boat. It was then dried in a tube furnace at 150℃ under a reducing atmosphere to obtain vanadium trioxide with a purity of 99.1%, with a yield of 77%. The yield of vanadium trioxide was calculated as: n(vanadium trioxide) / 2n(sodium vanadate); where n is the amount of substance.
[0057] Therefore, the purity and yield of the vanadium trioxide product in Comparative Example 1 are far lower than those in this application, and the reduction temperature is as high as 600℃, resulting in significant energy waste.
Claims
1. A method for preparing vanadium trioxide, characterized in that, The preparation method includes the following steps: (1) Mix sodium vanadate and succulent powder, and ball mill to obtain a mixture powder; (2) The mixture powder is roasted in a tube furnace at 350-500 degrees Celsius for 2-4 hours under a nitrogen atmosphere to obtain roasted clinker; (3) The roasted clinker is washed and dried to obtain the final product vanadium trioxide; In step (1), the molar ratio of sodium vanadate to sodium chloroform is 1:1 to 1:
4. The sodium vanadate salt is at least one of sodium metavanadate, sodium orthovanadate, sodium pyrovanadate, and sodium tetravanadate.
2. The method for preparing vanadium trioxide according to claim 1, characterized in that, The specific washing operation is as follows: add water to the roasted calcined material, raise the water temperature to 80-100℃, stir for 1-2 hours to fully mix and dissolve, then filter and extract the filter cake.
3. The method for preparing vanadium trioxide according to claim 2, characterized in that, The drying temperature is 60~120 degrees Celsius, and the drying time is 1~2 hours.