A system for recovering vanadium from AMV vanadium precipitation supernatant and a method thereof

Abstract

The present application relates to a kind of AMV vanadium precipitation upper layer liquid vanadium recovery system, comprising: reaction tank, its lower part is inverted cone body, top and AMV upper layer liquid pipe and first exhaust pipe are communicated, acid pipe is communicated with the position of being set with acid ring pipe adjacent top, side and upper layer liquid discharge pipe are communicated, inverted cone body is installed with first, second and third sight glass in sequence on one side, first agitator is installed in reaction tank, the bottom of inverted cone body is provided with first discharge port;Return dissolving tank, its top and first discharge port, second exhaust pipe, vanadium liquid pipe and liquid alkali pipe are communicated, second agitator is installed in inside, second discharge port is provided with, second discharge port is connected with pump, and pump is pumped from the return solution of second discharge port to liquid storage tank storage or AMV vanadium precipitation tank vanadium precipitation.In addition, the present application also relates to a kind of vanadium recovery method using above-mentioned system.The present application recovers the vanadium in AMV upper layer liquid, improves vanadium yield, reduces production cost.

Description

Technical Field

[0001] This invention belongs to the field of hydrometallurgical technology, and more specifically, relates to a system and method for recovering vanadium from the upper layer of AMV vanadium precipitation solution. Background Technology

[0002] The existing process for producing vanadium powder (V2O598.0-P, V2O599.0-P, V2O599.5-P, V2O599.8-P, battery grade) is as follows: vanadium slag is sodium-roasted and then leached in water to obtain a vanadium-containing leachate. The vanadium-containing leachate is purified and impurities are removed multiple times to obtain a relatively pure vanadium-containing solution. Vanadium is then precipitated from the vanadium-containing solution to obtain AMV. After drying the AMV, it is calcined in a rotary kiln to obtain vanadium powder.

[0003] The vanadium concentration in the upper layer of the AMV vanadium precipitation solution in this process is about 2.0 g / L, resulting in a low vanadium yield and high production cost in vanadium powder production.

[0004] The paper "A Method for Selectively Recovering Vanadium and Cesium from Waste Vanadium Sulfate Catalysts and the High-Quality Vanadium Aqueous Solution and Cesium Alum Prepared by This Method," authored by Quan Haoxi, discloses a wet smelting method for selectively recovering vanadium and cesium from waste vanadium sulfate catalysts, including water leaching, solid-liquid separation, vanadium solvent extraction, selective vanadium removal, and cesium alum preparation. The method involves adding an organic solvent to a vanadium-containing solution to extract vanadium into the extract, followed by back-extraction with an alkaline aqueous solution to obtain a high-quality vanadium aqueous solution. This production process is lengthy and costly; the operation is complex and involves organic solvents, requiring high levels of on-site production control.

[0005] Therefore, existing technologies need to be improved. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the present invention aims to provide a system and method for recovering vanadium from the upper layer of AMV vanadium precipitation solution. Specifically, acid is added to the upper layer of AMV vanadium precipitation solution to adjust the pH to 4-6, utilizing the NH4+ in the original solution. + Vanadium was precipitated with a weakly acidic ammonium salt, and the vanadium concentration in the upper layer decreased from 2.0 g / L to 0.6 g / L. The resulting slurry was then used as a new AMV precipitating solution for back dissolution, thereby recovering the vanadium in the upper layer of the AMV precipitating solution.

[0007] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0008] According to one aspect of the present invention, a system for recovering vanadium from the upper layer of an AMV vanadium precipitation solution is provided, comprising:

[0009] The reaction vessel has an inverted cone shape at the bottom. The top of the reaction vessel is connected to the upper liquid pipe of the AMV and the first exhaust pipe. An acid addition ring pipe is installed near the top of the reaction vessel and is connected to the acid pipe outside the reaction vessel. The side of the reaction vessel is connected to the upper liquid discharge pipe. A first sight glass, a second sight glass and a third sight glass are installed sequentially on one side of the inverted cone. A first stirrer is installed inside the reaction vessel. A first discharge port is provided at the bottom of the inverted cone of the reaction vessel.

[0010] The top of the remelting tank is connected to the first discharge port via a bottom flow valve. The top of the remelting tank is also connected to the second exhaust pipe, vanadium liquid pipe, and liquid alkali pipe. A second stirrer is installed inside the remelting tank, and a second discharge port is provided at the bottom of the remelting tank. The second discharge port is connected to a pump via a bottom valve. The pump pumps the remelting solution from the second discharge port to a storage tank for storage or to an AMV vanadium precipitation tank for vanadium precipitation.

[0011] In one embodiment of the present invention, a first level gauge is installed on the top of the reaction vessel, and a second level gauge is installed on the top of the remelting vessel.

[0012] In one embodiment of the present invention, a first pH meter and a first thermometer are also installed on the side of the reaction vessel, and a second pH meter and a second thermometer are installed on the side of the remelting vessel.

[0013] In one embodiment of the present invention, a support is also provided inside the reaction vessel to support the acid addition loop pipe.

[0014] In one embodiment of the present invention, the support is composed of a plurality of studs evenly distributed on the inner wall of the reaction vessel and protruding on the same horizontal plane.

[0015] In one embodiment of the present invention, the acid-adding ring tube is an acid-resistant plastic tube and has a plurality of uniformly distributed small holes located directly below the liquid surface.

[0016] In one embodiment of the present invention, a first inclined branch pipe with an inclination angle of ≥5° is provided on the outer wall side of the reaction vessel, and the upper liquid discharge pipe is connected to the first inclined branch pipe.

[0017] In one embodiment of the present invention, three second inclined branch pipes with an inclination angle ≥30° are provided on the outer wall side of the inverted cone, and the first sight mirror, the second sight mirror and the third sight mirror are respectively installed on the corresponding second inclined branch pipes.

[0018] According to another aspect of the present invention, a method for recovering vanadium using a system for recovering vanadium from the AMV vanadium precipitation supernatant as described above is provided, comprising the following steps:

[0019] 1) Add the AMV supernatant and dilute acid to the reaction vessel to carry out the reaction;

[0020] 2) The gas after the reaction in the reaction tank is completed is discharged through the first exhaust pipe, the obtained upper liquid is discharged through the upper liquid discharge pipe, and the obtained slurry is discharged into the return tank;

[0021] 3) Add vanadium solution and liquid alkali to the remelting tank for adjustment and reaction;

[0022] 4) The gas produced after the reaction in the remelting tank is completed is discharged through the second exhaust pipe, and the remelting solution in the remelting tank is pumped back to the storage tank for storage or to the AMV vanadium precipitation tank for vanadium precipitation.

[0023] In one embodiment of the present invention, when the pH of the reflux solution in the reflux tank is ≥9.0, the reflux solution is pumped to a storage tank for storage or to an AMV vanadium precipitation tank for vanadium precipitation.

[0024] By adopting the above technical solution, the present invention has the following advantages compared with the prior art:

[0025] (1) This invention makes full use of NH4 in the upper layer of AMV + Due to its high content, acid is added to adjust the pH of the solution to 4-6. Under weakly acidic conditions, vanadium in the upper layer of AMV reacts with NH4+. + The slurry recombines to form solid particles, which settle at the bottom of the tank. After the bottom slurry is recovered, an alkaline solution is added to it for back dissolution to generate a new vanadium-containing solution. The pH value of the sodium vanadium solution is 10.5-11.5, which is then used as the alkaline solution for back dissolution of the bottom slurry.

[0026] (2) This invention makes full use of the material characteristics in its own production process, without introducing new reagents and impurities, recovers vanadium in the upper layer of AMV, improves vanadium yield, and reduces production costs.

[0027] (3) The equipment integration and technology described in this invention can be industrialized, with low labor intensity, high degree of automation, and low production cost. Attached Figure Description

[0028] Figure 1 A schematic diagram of the system for recovering vanadium from the upper layer of AMV vanadium precipitation solution provided by the present invention is shown.

[0029] Figure 2 A schematic flowchart of the method for recovering vanadium from the upper layer of AMV vanadium precipitation solution provided by the present invention is shown.

[0030] List of reference numerals

[0031] 1 Flow meter, 2 AMV upper liquid pipe, 3 First liquid level gauge, 4 First stirrer, 5 First vent pipe, 6 Acid pipe, 7 Support, 8 Reaction tank, 9 First pH meter, 10 First thermometer, 11 Acid addition loop pipe, 12 Upper liquid discharge pipe, 13 First sight glass, 14 Second sight glass, 15 Third sight glass, 16 Underflow valve, 17 Second vent pipe, 18 Second stirrer, 19 Second liquid level gauge, 20 Vanadium liquid pipe, 21 Liquid alkali pipe, 22 Redissolution tank, 23 Second pH meter, 24 Second thermometer, 25 Tank bottom valve, 26 Pump, 27 First inclined branch pipe, 28 Second inclined branch pipe, 29 First discharge port, 30 Second discharge port. Detailed Implementation

[0032] It should be understood that the embodiments of the invention shown in the exemplary embodiments are merely illustrative. Although only a few embodiments have been described in detail in this invention, those skilled in the art will readily recognize that various modifications are possible without substantially departing from the teachings of the invention. Accordingly, all such modifications should be included within the scope of the invention. Other substitutions, modifications, variations, and deletions can be made to the design, operating conditions, and parameters of the following exemplary embodiments without departing from the spirit of the invention.

[0033] like Figure 1 As shown, the present invention provides a system for recovering vanadium from the upper layer of an AMV vanadium precipitation solution, comprising:

[0034] The reaction vessel 8 has an inverted cone shape at its lower part. The top of the reaction vessel 8 is connected to the upper liquid pipe 2 of the AMV and the first exhaust pipe 5. A support 7 is installed near the top of the reaction vessel 8, and an acid adding ring pipe 11 is supported on the support 7. The acid adding ring pipe 11 is connected to the acid pipe 6 outside the reaction vessel. A first inclined branch pipe 27 is installed on one side of the reaction vessel 8, and the first inclined branch pipe 27 is connected to the upper liquid discharge pipe 12. A first pH meter 9 and a first thermometer 10 are installed on the other side of the reaction vessel 8. A second inclined branch pipe 28 is installed on one side of the inverted cone shape. A first sight glass 13, a second sight glass 14 and a third sight glass 15 are installed on the corresponding second inclined branch pipe 28. A first stirrer 4 is installed inside the reaction vessel 8. A first discharge port 29 is installed at the bottom of the inverted cone shape of the reaction vessel 8.

[0035] The top of the remelting tank 22 is connected to the first outlet 29 via the bottom flow valve 16. The top of the remelting tank 22 is connected to the second exhaust pipe 17, the vanadium liquid pipe 20, and the liquid alkali pipe 21. The interior of the remelting tank 22 is equipped with a second stirrer 18. The side of the remelting tank 22 is equipped with a second pH meter 23 and a second thermometer 24. The bottom of the remelting tank 22 is provided with a second outlet 30. The second outlet 30 is connected to a pump 26 via a bottom valve 25. The pump 26 pumps the remelting solution from the second outlet 30 to a storage tank for storage or to an AMV vanadium precipitation tank for vanadium precipitation.

[0036] In the above system, preferably, a first level gauge 1 is installed on the top of the reaction tank 8, and a second level gauge 19 is installed on the top of the remelting tank 22.

[0037] In the above system, preferably, the support 7 is composed of a plurality of studs that are evenly distributed on the inner wall of the reaction vessel 8 and protrude on the same horizontal plane.

[0038] In the above system, preferably, the acid-adding ring tube is an acid-resistant plastic tube and has multiple evenly distributed small holes located directly below the liquid surface.

[0039] In the above system, preferably, the inclination angle of the first inclined branch pipe 27 is ≥5°, and the inclination angle of the second inclined branch pipe is ≥30°.

[0040] like Figure 2 As shown, the present invention also provides a method for recovering vanadium using the AMV vanadium precipitation supernatant system described above, comprising the following steps:

[0041] 1) Add the AMV supernatant and dilute acid to the reaction vessel to carry out the reaction;

[0042] 2) After the reaction is complete, the gas in the reaction tank is discharged through the first exhaust pipe, the obtained upper liquid is discharged through the upper liquid discharge pipe, and the obtained slurry is discharged into the remelting tank;

[0043] 3) Add vanadium solution and liquid alkali to the remelting tank for adjustment and reaction;

[0044] 4) The gas produced after the reaction in the remelting tank is completed is discharged through the second exhaust pipe, and the remelting solution in the remelting tank is pumped back to the storage tank for storage or to the AMV vanadium precipitation tank for vanadium precipitation.

[0045] In the above method, preferably, when the pH of the returned solution in the return solution tank is ≥9.0, the returned solution is pumped to the storage tank for storage or to the AMV vanadium precipitation tank for vanadium precipitation.

[0046] The technical solutions of the present invention will be described in detail below through specific embodiments.

[0047] like Figure 1-2As shown, the first flow meter is installed on the AMV upper liquid pipe 2 to measure the AMV upper liquid entering the reaction tank 8. The first level gauge 3 is installed on the top of the reaction tank 8 to measure the liquid level change inside the reaction tank 8. When the solution level in the reaction tank 8 submerges the lower blades of the first stirrer 4 and the probe of the first pH meter 9, the first stirrer 4 is turned on to stir the liquid in the reaction tank 8. The valve on the acid pipe 6 is opened to add acid to the solution in the reaction tank 8 through the acid adding ring pipe 11, and the pH value is controlled at 5.5-6.5. When the liquid level in the reaction tank 8 reaches the specified level, the liquid supply is stopped. Generally, the empty space in the reaction tank 8 is reserved at 500mm. The first exhaust pipe 5 is located on the top of the reaction tank 8 and connected to the degassing main pipe to remove the gas generated during the vanadium precipitation process. The first pH meter 9 and the first thermometer 10 are installed on the side of the reaction tank 8 to measure the pH value and temperature of the solution in the reaction tank 8, respectively. The support 7 consists of multiple protruding supports evenly distributed on the inner wall of the reaction vessel 8 at the same horizontal plane. This support 7 supports the acid-adding ring pipe 11. The acid-adding ring pipe 11 is preferably made of acid-resistant plastic. It is connected to the acid pipe 6 and is approximately 200mm from the top of the reaction vessel 8. The acid-adding ring pipe 11 has multiple evenly distributed φ6mm small holes located directly below the liquid surface. The total area of ​​all the small holes on the acid-adding ring pipe 11 is greater than the cross-sectional area of ​​the pipe to prevent pressure buildup and jetting. Preferably, the added acid is dilute sulfuric acid, which is prepared by mixing pure water and 98% concentrated sulfuric acid in a certain proportion. Directly adding concentrated sulfuric acid will cause the solution in the reaction vessel 8 to react violently, produce a large amount of fumes, and be prone to hydrolysis; too low a sulfuric acid concentration will result in a large amount of wastewater, which is not conducive to low-cost manufacturing. Therefore, the preferred ratio is pure water to 98% concentrated sulfuric acid of 1:1-3:1 (volume ratio). The ideal temperatures for both the AMV supernatant and dilute sulfuric acid are below 30°C (room temperature). The preferred conditions for vanadium precipitation are: room temperature for both the AMV supernatant and dilute sulfuric acid; dilute acid; multi-point acid addition via a loop; and stirring. These conditions are designed to ensure stable pH control during vanadium precipitation and to prevent a rapid precipitation reaction.

[0048] When the liquid level in reaction tank 8 is 500mm from the top of the tank, stop the AMV upper layer liquid inlet and continue stirring. Add acid to adjust the pH of the solution to 4.5-5.0, then continue stirring for 1 hour, while controlling the final pH of the solution to 4.5-5.0. After stirring for 1 hour, stop the first stirrer 4. After the solution in reaction tank 8 has stood for 2 hours, open the valve on the upper layer liquid discharge pipe 12 to drain the upper layer liquid from reaction tank 8.

[0049] When the liquid level in the reaction tank 8 is at the upper liquid discharge pipe 12, find the change in liquid level displayed by the first level gauge 3 when the slurry level drops from the first sight glass 13 to the second sight glass 14; when the liquid level in the reaction tank 8 is at the upper liquid discharge pipe 12, also find the change in liquid level displayed by the first level gauge 3 when the slurry level drops from the second sight glass 14 to the third sight glass 15. The upper liquid discharge pipe 12 is connected to the first inclined branch pipe 27 on the outer wall of the reaction tank 8. The first inclined branch pipe 27 is inclined upward with an inclination angle ≥5° to avoid particulate material settling at the pipe opening and reduce vanadium loss when discharging the upper liquid. The first sight glass 13, the second sight glass 14, and the third sight glass 15 are connected to the corresponding second inclined branch pipes 28 on the outer wall of the inverted cone-shaped body at the bottom of the reaction vessel 8. These second inclined branch pipes 28 are inclined upward with an inclination angle of ≥30° to ensure that the material deposited on the second inclined branch pipes 28 can fall off during the process of opening the bottom flow valve 16 to discharge the slurry in the reaction vessel 8, thereby facilitating observation.

[0050] After the solution in reaction tank 8 has been allowed to stand for 2 hours, the slurry level at the bottom of reaction tank 8 is checked using the first sight glass 13, the second sight glass 14, and the third sight glass 15. When the slurry level at the bottom of reaction tank 8 is below the third sight glass 15, the slurry in reaction tank 8 should not be discharged. After draining the upper liquid through the upper liquid drain pipe 12, continue adding AMV upper liquid and start the first stirrer 4. The slurry in reaction tank 8 serves as seed crystals for the next AMV upper liquid vanadium precipitation operation. When the slurry level at the bottom of reaction tank 8 is between the first sight glass 14 and the third sight glass 15, the slurry in reaction tank 8 can be discharged according to the actual situation. When the slurry level at the bottom of the reaction tank 8 is between the first sight glass 13 and the second sight glass 14 or above the first sight glass 13, open the underflow valve 16 to discharge the slurry in the reaction tank 8 into the remelting tank 22. When the slurry level is between the second sight glass 14 and the third sight glass 15, close the underflow valve 16 to ensure the amount of seed crystals for the next AMV upper layer vanadium precipitation operation.

[0051] The outlet of the underflow valve 16 is connected to the top of the remelting tank 22. The second vent pipe 17 is located on the top of the remelting tank 22 and connected to the degassing main pipe to remove gases generated during the remelting process. The second level gauge 19 is installed on the top of the remelting tank 22 to measure changes in the liquid level within the tank. The vanadium liquid pipe 20 and the alkali liquid pipe 21 are located on the top of the remelting tank 22, conveying the alkaline solution used as the remelting slurry. The second pH meter 23 and the second thermometer 24 are installed on the lower side wall of the remelting tank 22 to measure the pH value and temperature of the solution within the tank, respectively.

[0052] After the slurry in reaction tank 8 is discharged into the return tank 22, the valve on the vanadium liquid pipe 20 is opened to add vanadium liquid to the return tank 22. When the liquid submerges the lower blades of the second agitator 18, the second agitator 18 is started. When the liquid level in the return tank 22 is 500mm from the top of the tank, the valve on the vanadium liquid pipe 20 is closed. After stirring for 0.5h, if the pH of the solution in the return tank 22 is ≥9.0, the bottom valve 25 is opened and the pump 26 is started to transport the return solution in the return tank 22 to the storage tank for storage or to the AMV vanadium precipitation tank for vanadium precipitation. If the pH of the solution in the return tank 22 is <9.0, the valve on the liquid alkali pipe 21 is opened to add liquid alkali until the pH is 9.0-9.5. After stirring for 0.5h, the bottom valve 25 is opened and the pump 26 is started to transport the return solution in the return tank 22 to the storage tank for storage or to the AMV vanadium precipitation tank for vanadium precipitation.

[0053] In the above-mentioned apparatus and method, preferably, the reaction vessel 8 has a cylindrical diameter of 3.0m, a height of 3.5m, and a bottom conical taper of 60°, and the remelting vessel 22 has a cylindrical diameter of 3.0m, a height of 3.5m, and an elliptical arc bottom (0.6m high).

[0054] After implementing this invention, the vanadium concentration in the upper layer of AMV can be reduced to 0.6 g / L.

[0055] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of the present invention. Any modifications or equivalent substitutions made to the present invention without departing from the spirit and scope thereof should be covered within the protection scope of the claims of the present invention.

Claims

1. A system for recovering vanadium from the upper layer of an AMV vanadium precipitation solution, characterized in that, Include: The reaction vessel has an inverted conical lower part. The top of the reaction vessel is connected to the upper liquid pipe of the AMV and the first exhaust pipe. An acid addition ring pipe is installed near the top of the reaction vessel and is connected to an acid pipe outside the reaction vessel. The side of the reaction vessel is connected to the upper liquid discharge pipe. A first sight glass, a second sight glass and a third sight glass are installed sequentially on one side of the inverted conical body. A first stirrer is installed inside the reaction vessel. A first discharge port is provided at the bottom of the inverted conical body of the reaction vessel. The remelting tank has its top connected to the first discharge port via a bottom flow valve. The top of the remelting tank is also connected to the second exhaust pipe, the vanadium liquid pipe, and the liquid alkali pipe. A second stirrer is installed inside the remelting tank. A second discharge port is provided at the bottom of the remelting tank. The second discharge port is connected to a pump via a bottom valve. The pump pumps the remelting solution from the second discharge port to a storage tank for storage or to an AMV vanadium precipitation tank for vanadium precipitation. The acid-adding ring tube is an acid-resistant plastic tube, and the acid-adding ring tube has multiple evenly distributed small holes near the liquid surface. The total area of ​​all the small holes on the acid-adding ring tube is greater than the cross-sectional area of ​​the acid-adding ring tube. A first inclined branch pipe with an inclination angle of ≥5° is provided on the outer wall side of the reaction vessel, and the upper liquid discharge pipe is connected to the first inclined branch pipe. The outer wall of the inverted cone is provided with three second inclined branch pipes with an inclination angle of ≥30°, and the first sight mirror, the second sight mirror and the third sight mirror are respectively installed on the corresponding second inclined branch pipes.

2. The system for recovering vanadium from the upper layer of AMV vanadium precipitation liquid according to claim 1, characterized in that, A first level gauge is installed on the top of the reaction vessel, and a second level gauge is installed on the top of the remelting vessel.

3. The system for recovering vanadium from the upper layer of AMV vanadium precipitation liquid according to claim 1, characterized in that, A first pH meter and a first thermometer are also installed on the side of the reaction vessel, and a second pH meter and a second thermometer are installed on the side of the remelting vessel.

4. The system for recovering vanadium from the upper layer of AMV vanadium precipitation liquid according to claim 1, characterized in that, The reaction vessel is also equipped with a support frame, which supports the acid addition loop pipe.

5. The system for recovering vanadium from the upper layer of AMV vanadium precipitation liquid according to claim 4, characterized in that, The support consists of multiple studs that are evenly distributed on the inner wall of the reaction vessel and protrude on the same horizontal plane.

6. A method for recovering vanadium using the AMV vanadium precipitation supernatant system as described in any one of claims 1-5, characterized in that, Includes the following steps: 1) Add the AMV supernatant and dilute acid to the reaction vessel to carry out the reaction; 2) The gas produced after the reaction in the reaction tank is completed is discharged through the first exhaust pipe, the obtained upper liquid is discharged through the upper liquid discharge pipe, and the obtained slurry is discharged into the return tank; 3) Add vanadium solution and liquid alkali to the remelting tank for adjustment and reaction; 4) The gas produced after the reaction in the remelting tank is completed is discharged through the second exhaust pipe, and the remelting solution in the remelting tank is pumped back to the storage tank for storage or to the AMV vanadium precipitation tank for vanadium precipitation.

7. The method according to claim 6, characterized in that, When the pH of the reflux solution in the reflux tank is ≥9.0, the reflux solution is pumped to the storage tank for storage or to the AMV vanadium precipitation tank for vanadium precipitation.

Images