A method for enriching and purifying vanadium by molten salt chlorination distillation

Abstract

This invention relates to a method for enriching and purifying vanadium by molten salt chlorination distillation. The technical solution is as follows: vanadium is enriched and purified using a "molten salt chlorination distillation reaction device for enriching and purifying vanadium". The specific method is as follows: a chlorinating agent is added to the molten salt device (2), heated and stirred, and the resulting chlorinated molten salt is discharged from the molten salt output pipe (14) through the second discharge valve (15) and enters the chlorination device (4) through the first pipe B from the molten salt input port (25); the solid vanadium source added to the chlorination device (4) is mixed with the chlorinated molten salt, heated and stirred to generate vanadium oxychloride gas; the vanadium oxychloride gas is discharged from the gas outlet B (35) and enters the condenser device (5) through the second pipe B from the gas inlet C (41); vanadium oxychloride liquid is obtained by condensation in the condenser (39), and the vanadium oxychloride liquid is collected through the collection tank (44). This invention has the characteristics of short process flow, good vanadium impurity separation effect, environmental friendliness, high process controllability, good safety, and high chlorination efficiency, and the vanadium oxychloride liquid obtained has high purity.

Description

Technical Field

[0001] This invention belongs to the field of vanadium enrichment and purification technology. Specifically, it relates to a method for enriching and purifying vanadium through molten salt chlorination distillation. Background Technology

[0002] Vanadium is a strategically important metal widely distributed in nature. Vanadium shale is a significant vanadium resource, and direct acid leaching is commonly used to extract vanadium from it. However, due to the complex mineral composition and low vanadium content of vanadium shale, a large number of impurities enter the leachate during the extraction process. Therefore, the enrichment and purification of vanadium shale leachate is crucial for the preparation of vanadium products. Currently, solvent extraction and ion exchange methods can be used to enrich and purify vanadium in vanadium shale leachate.

[0003] The patented technology, "Extraction Method for Vanadium from Vanadium-Containing Solution" (CN109306404B), involves countercurrent extraction of sulfuric acid from a vanadium-containing solution using an organic phase A containing an amine extractant, yielding a raw extract and a loaded organic phase A. The raw extract is then countercurrently extracted using an organic phase B containing a phosphorus extractant, yielding a raffinate and a loaded organic phase B. Finally, an aqueous sulfuric acid solution is used as a back-extraction agent to back-extract the loaded organic phase B, resulting in a lean organic phase B and a vanadium-rich solution. While this technology achieves vanadium enrichment and purification, the two countercurrent extraction stages require 2–6 stages and 3–5 stages respectively, resulting in a long process flow. Furthermore, the purity of the obtained vanadium pentoxide product is only 99%, which is low.

[0004] The patented technology, "A Method for Extracting Vanadium from Waste Hydrodesulfurization Catalyst Using Anion Exchange Resin" (CN117587267A), involves leaching ground waste hydrodesulfurization catalyst powder with sulfuric acid solution. After oxidation and neutralization of the leachate, anion exchange resin is used to adsorb vanadium compounds in the pentavalent vanadium leachate. A desorbent is then used to desorb the adsorbed vanadium compounds from the anion exchange resin, resulting in a vanadium ion-enriched solution. While this technology achieves vanadium enrichment and purification, the resulting vanadium ion-enriched solution still contains 5% iron ions, indicating poor vanadium-impurity separation.

[0005] The patented technology, "A Method for Preparing Refined Vanadium Oxide Trichloride from Vanadium-Containing Refined Tailings" (CN115947370A), uses vanadium-containing refined tailings as raw material. The tailings are treated at high temperature under an inert gas atmosphere to obtain pretreated refined tailings. After cooling, a mixture of oxygen and chlorine is continuously introduced for reaction. After the reaction, the mixed gas is discharged and condensed at low temperature to obtain liquid vanadium oxychloride trichloride. Although this technology achieves vanadium enrichment and purification, the required chlorination temperature is high, resulting in the simultaneous chlorination of some impurities, necessitating additional purification processes. Furthermore, the use of chlorine as the chlorinating agent pollutes the environment, has low process controllability, and poor safety.

[0006] The literature (Jiang Dandan. Research on the purification process of vanadium pentoxide by low-temperature chlorination of aluminum chloride [D]. University of Chinese Academy of Sciences (Institute of Process Engineering, Chinese Academy of Sciences), 2017.) discloses a process for purifying vanadium pentoxide by low-temperature chlorination of aluminum chloride. This process uses industrial-grade vanadium pentoxide as raw material and aluminum chloride and sodium chloride as chlorinating agents. High-purity vanadium oxychloride is obtained by low-temperature chlorination in a traditional small-scale distillation series reaction device, thus achieving vanadium enrichment and purification. However, the traditional small-scale distillation series reaction device used in this process is difficult to use industrially. The series placement of multiple independent devices such as distillation flasks, condensers, receiving tanks, and tail gas treatment equipment requires long pipelines and many valve connections, which increases the risk of leakage of vanadium oxychloride and results in poor safety. The lack of a stirring device in the equipment leads to a decrease in chlorination efficiency, with a vanadium extraction rate of 75% and incomplete reaction.

[0007] In summary, existing methods for enriching and purifying vanadium suffer from problems such as long process flow, poor vanadium-impurity separation, environmental unfriendliness, low process controllability, poor safety, low chlorination efficiency, and low purity. Summary of the Invention

[0008] This invention aims to overcome the shortcomings of existing technologies and provides a method for enriching and purifying vanadium by molten salt chlorination distillation, which features a short process flow, good vanadium-impurity separation effect, environmental friendliness, high process controllability, good safety, and high chlorination efficiency. The vanadium oxychloride liquid obtained by this method has high purity.

[0009] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0010] A method for enriching and purifying vanadium by molten salt chlorination distillation, wherein the equipment used in the method is a "molten salt chlorination distillation reaction device for enriching and purifying vanadium", the equipment including a molten salt device, a chlorination device, a condensation device, a high-temperature circulating oil bath A and a high-temperature circulating oil bath B;

[0011] The method for enriching and purifying vanadium by molten salt chlorination distillation is as follows:

[0012] Step 1: Preparation of chlorinated molten salt. Add chlorinating agent to the molten salt apparatus, heat the molten salt apparatus in an oil bath, set the heating temperature to 130-250℃, and react under stirring to obtain chlorinated molten salt.

[0013] Step 2: Chlorination reaction. Add molten chlorinated salt and solid vanadium source to the chlorination device, heat the chlorination device in an oil bath, set the heating temperature to 160-200℃, and react under stirring to obtain vanadium oxychloride gas.

[0014] Step 3: Condensation and collection. The obtained vanadium oxychloride gas is introduced into a condenser and condensed to obtain vanadium oxychloride liquid.

[0015] Step 1 is as follows:

[0016] Step 1.1: Add the chlorinating agent into the molten salt device through the feed port A of the molten salt device, according to the ratio of the volume of the chlorinating agent to the volume of the molten salt device being 0.3 to 0.8:1.

[0017] Step 1.2: Set the temperature of the high-temperature circulating oil bath A to 130-250℃. The heated silicone oil enters the jacket A from the oil outlet A of the oil bath through the second heat insulation pipe A from the oil inlet of the molten salt device. The silicone oil that enters the jacket A then enters the high-temperature circulating oil bath A from the oil outlet A of the molten salt device through the first heat insulation pipe A from the oil inlet A of the oil bath to circulate and heat the molten salt device.

[0018] Step 1.3: When the temperature sensor A in the molten salt device reaches the set temperature of the high-temperature circulating oil bath A, the stirrer A stirs at a speed of 150-500 r / min for 30-60 min to obtain chlorinated molten salt.

[0019] Step 1.4: Open the second discharge valve of the molten salt device to allow the chlorinated molten salt to enter the chlorination device from the molten salt output pipe of the molten salt device through the first pipe B and the molten salt input port; close the second discharge valve and open the first discharge valve to discharge the residual chlorinated molten salt through the discharge pipe.

[0020] Step 2 is as follows:

[0021] Step 2.1: Add the solid vanadium source to the chlorination device through the feed port B of the chlorination device, according to the molar ratio of vanadium to chlorinating agent in the solid vanadium source being 1:1 to 4.

[0022] Step 2.2: Set the temperature of the high-temperature circulating oil bath B to 160-200℃. The heated silicone oil enters the jacket B from the oil outlet B of the oil bath through the second insulation pipe B from the oil inlet of the chlorination unit. The silicone oil that enters the jacket B then enters the high-temperature circulating oil bath B from the oil outlet B of the chlorination unit through the first insulation pipe B from the oil inlet B of the oil bath to circulate and heat the chlorination unit.

[0023] Step 2.3: When the temperature sensor B of the chlorination unit reaches the set temperature of the high-temperature circulating oil bath B, the stirrer B starts stirring at a speed of 200-600 r / min; at the same time, the external protective gas is input from the air inlet B of the chlorination unit, and the stirrer B stirs for 1-3 hours to obtain vanadium oxychloride gas.

[0024] Step 2.4: The vanadium oxychloride gas enters the condenser from the outlet B of the chlorination unit through the second pipe B and the inlet C; the slag discharge valve is opened to discharge the chlorination reaction residue through the slag discharge pipe.

[0025] Step 3 is as follows:

[0026] Step 3.1: Input the refrigerant into the condenser from the liquid inlet at the lower end of the serpentine condenser tube of the condensing device, and then let it flow out from the liquid outlet at the upper end of the serpentine condenser tube. The flow rate of the refrigerant is 1 to 4 m / s.

[0027] Step 3.2: The vanadium oxychloride gas entering the condenser enters the condenser from the collection tank through the outlet C, and after condensation, vanadium oxychloride liquid is obtained. The vanadium oxychloride liquid flows back into the collection tank through the outlet C; the tail gas is discharged from the tail gas collection pipe.

[0028] Step 3.3: Open the collection valve of the condenser to obtain the vanadium oxychloride liquid.

[0029] The vanadium oxychloride liquid is mixed with a solvent to obtain a vanadium-rich solution, which is used in subsequent processes.

[0030] A molten salt chlorination distillation reactor for enriching and purifying vanadium includes...

[0031] The molten salt device is a jacketed tank with stirring, and is equipped with at least a feed port A at the top and at least a discharge pipe and a molten salt output pipe at the bottom;

[0032] The chlorination unit is a jacketed tank with stirring, and the top is equipped with at least a molten salt inlet, a feed port B and a gas outlet B, and the bottom is equipped with at least a slag discharge pipe.

[0033] A condenser, connected to outlet B, is used to condense the gas evaporated from the chlorination unit; a high-temperature circulating oil bath is used to heat the jacket of the molten salt unit and the chlorination unit respectively.

[0034] The molten salt device consists of a speed controller A, a stirrer A, a main body A, a temperature sensor A, a cover plate A, and a motor A.

[0035] The main body A is a double-layered cylindrical shape, with a sandwich layer A between the outer and inner walls of the main body A. The sandwich layer A is filled with high-temperature silicone oil, which heats the main body A. The ports of the main body A are fixedly connected to the cover plate A by bolts, and a sealing ring is provided between the main body A and the cover plate A.

[0036] A feeding port A is located on one side of the center of cover plate A, and a temperature sensor through hole A is located on the other side of the center of cover plate A. The temperature measuring end of temperature sensor A passes through the temperature sensor through hole A into the lower part of the inner cavity of body A, and the wiring terminal of sensor A is externally connected to speed controller A. A stirrer through hole A is located at the center of cover plate A, and the lower end of stirrer A passes through the stirrer through hole A into the lower part of the inner cavity of body A. A stirring paddle A is located at the lower end of stirrer A, and the upper end of stirrer A is connected to the output shaft of motor A via a coupling. The wiring terminal of motor A is externally connected to speed controller A.

[0037] A molten salt device outlet is located on the upper part of one side of the outer surface of the circular wall of body A, and a molten salt device inlet is located on the lower part of the other side of the outer surface of the circular wall of body A. A discharge port is located at the center of the bottom of body A, and the discharge port is equipped with a discharge pipe and a molten salt output pipe. A first discharge valve is located at the opening of the discharge pipe, and a second discharge valve is located at the opening of the molten salt output pipe. The molten salt device outlet is connected to the oil bath inlet A of the high-temperature circulating oil bath A through a first insulation pipe A, and the molten salt device inlet is connected to the oil bath outlet A of the high-temperature circulating oil bath A through a second insulation pipe A.

[0038] The chlorination device consists of a speed controller B, a stirrer B, a main body B, a cover plate B, a temperature sensor B, and a motor B.

[0039] The main body B is a double-layered cylindrical shape, with a sandwich layer B between the outer and inner walls of the main body B. The sandwich layer B is filled with high-temperature silicone oil, which heats the main body B. The ports of the main body B are fixedly connected to the cover plate B by bolts, and a sealing ring is provided between the main body B and the cover plate B.

[0040] On one side of the center of cover plate B, from the outside in, are arranged a molten salt inlet, an air inlet B, and a feed inlet B. On the other side of the center of cover plate B, from the inside out, are arranged a temperature sensor through-hole B and an air outlet B. The temperature measuring end of temperature sensor B passes through the temperature sensor through-hole B into the lower part of the inner cavity of body B, and the wiring terminal of temperature sensor B is externally connected to speed controller B. At the center of cover plate B, there is a stirrer through-hole B. The lower end of stirrer B passes through the stirrer through-hole B into the lower part of the inner cavity of body B. A stirring paddle B is located at the lower end of stirrer B. The upper end of stirrer B is connected to the output shaft of motor B via a coupling, and the wiring terminal of motor B is externally connected to speed controller B.

[0041] The upper part of one side of the outer surface of the circular wall of body B is provided with an oil outlet of the chlorination device, and the lower part of the other side of the outer surface of the circular wall of body B is provided with an oil inlet of the chlorination device; a slag discharge pipe is provided at the center of the bottom of body B, and a slag discharge valve is provided at the pipe opening of the slag discharge pipe.

[0042] The oil outlet of the chlorination unit is connected to the oil inlet B of the high-temperature circulating oil bath via the first insulation pipe B, and the oil inlet of the chlorination unit is connected to the oil outlet B of the high-temperature circulating oil bath via the second insulation pipe B.

[0043] The condensation device consists of a collection tank and a condenser.

[0044] The collection tank is a hollow sphere. A collection pipe is provided at the bottom of the hollow sphere, and a collection valve is provided at the opening of the collection pipe. An air inlet C is provided on the left side of the hollow sphere, and an air outlet C is provided at the top of the hollow sphere.

[0045] The condenser consists of a condenser tube shell, a serpentine condenser tube, and a tail gas collection pipe. The serpentine condenser tube and the tail gas collection pipe are coaxially installed inside the condenser tube shell. The lower end of the serpentine condenser tube extends out of the lower part of the condenser tube shell and serves as the liquid inlet. The upper end of the serpentine condenser tube extends out of the upper part of the condenser tube shell and serves as the liquid outlet. The liquid inlet is connected to the outlet pipe of the low-temperature coolant circulator, and the liquid outlet is connected to the inlet pipe of the low-temperature coolant circulator.

[0046] The outlet C of the collection tank is fixedly connected to the lower end of the condenser tube shell of the condenser.

[0047] The molten salt output pipe of the molten salt unit is connected to the molten salt input port of the chlorination unit through the first pipe B. The produced molten salt is output from the molten salt output pipe and enters the chlorination unit through the first pipe B from the molten salt input port. The gas outlet B of the chlorination unit is connected to the gas inlet C of the collection tank through the second pipe B. The produced vanadium oxychloride gas is output from the gas outlet B and enters the condensation unit through the second pipe B from the gas inlet C.

[0048] The chlorinating agent is aluminum chloride, or a mixture of aluminum chloride and sodium chloride, or a mixture of aluminum chloride and zinc chloride.

[0049] The silicone oil is methyl silicone oil or phenyl silicone oil.

[0050] The solid vanadium source is obtained by oxidizing and then hydrolyzing vanadium from vanadium shale leachate; the vanadium content in the solid vanadium source is ≥10wt%.

[0051] The condenser is one of water, ethanol, and ethylene glycol; the condensation temperature of the condenser is -10 to 20°C.

[0052] The protective gas is nitrogen or argon; the flow rate of the protective gas is 5–20 L / min.

[0053] The solvent is one of water, hydrochloric acid, and sulfuric acid.

[0054] By adopting the above technical solution, the present invention has the following advantages compared with the prior art:

[0055] 1. This invention employs a molten salt chlorination distillation reactor for vanadium enrichment and purification. Compared with existing solvent extraction and ion exchange methods, after vanadium shale leachate undergoes oxidation-hydrolysis precipitation of vanadium, a single-stage chlorination distillation process can produce vanadium oxychloride liquid with a purity ≥99.9%. This eliminates the need for multi-stage continuous processes, resulting in a shorter process flow and better vanadium impurity separation. Consequently, the obtained vanadium oxychloride has high purity, and the further obtained vanadium pentoxide product has a purity ≥99.9%.

[0056] 2. This invention uses low-temperature molten salt as a chlorinating agent, which destroys the structure of the solid vanadium source through wetting, thereby releasing vanadium. The reaction temperature is 160–200℃, which is more environmentally friendly than using chlorine gas as a chlorinating agent, and the process has high controllability and good safety.

[0057] 3. The "molten salt chlorination distillation reaction device for enriching and purifying vanadium" used in this invention is a multi-functional integrated structure, combining the molten salt device, chlorination device, and condensation device into one unit. Compared with existing series reaction devices, this invention reduces the number of pipes and valves used, makes vanadium oxychloride gas less prone to leakage, and ensures high safety. Furthermore, compared with the integrated chlorination reaction device in the prior art, the molten salt device and chlorination device can also prevent some chlorides from volatilizing due to heat during the preparation of molten salt, preventing the volatilized chlorides from adhering to the inner wall of the chlorination device and entering the vanadium oxychloride gas, thereby effectively inhibiting the reduction of the purity of the reaction product. Stirrer A and stirrer B are respectively installed in the molten salt device and the chlorination device. Stirrer A and stirrer B increase the contact area between molten salts and between the solid vanadium source and the molten salt, improving the molten salt preparation efficiency and chlorination efficiency, with a vanadium extraction rate of over 85%.

[0058] Therefore, this invention has the advantages of short process flow, good vanadium impurity separation effect, environmental friendliness, high process controllability, good safety and high chlorination efficiency. The vanadium oxychloride liquid prepared by this method has high purity. Attached Figure Description

[0059] Figure 1 This is a schematic diagram of a molten salt chlorination distillation reactor for enriching and purifying vanadium used in this invention.

[0060] Figure 2 for Figure 1 An enlarged schematic diagram of a molten salt device 2 is shown;

[0061] Figure 3 for Figure 1 An enlarged schematic diagram of a high-temperature circulating oil bath A1 is shown.

[0062] Figure 4 for Figure 1 An enlarged schematic diagram of a chlorination device 4 is shown;

[0063] Figure 5 for Figure 1 An enlarged schematic diagram of another high-temperature circulating oil bath, B3, is shown.

[0064] Figure 6 for Figure 1 An enlarged schematic diagram of a condensation device 5 is shown. Detailed Implementation

[0065] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but this is not intended to limit the scope of protection thereof.

[0066] Example 1

[0067] A method for enriching and purifying vanadium by molten salt chlorination distillation. The equipment used in the method is a "molten salt chlorination distillation reaction apparatus for enriching and purifying vanadium", which includes a molten salt apparatus 2, a chlorination apparatus 4, a condensation apparatus 5, a high-temperature circulating oil bath A1, and a high-temperature circulating oil bath B3.

[0068] The method for enriching and purifying vanadium by molten salt chlorination distillation is as follows:

[0069] Step 1: Preparation of molten chloride salt

[0070] Step 1.1: Add the chlorinating agent into the molten salt device 2 through the feed port A7 of the molten salt device 2 according to the ratio of the volume of the chlorinating agent to the volume of the molten salt device 2 being 0.3:1.

[0071] Step 1.2: Set the temperature of the high-temperature circulating oil bath A1 to 130℃. The heated silicone oil enters the jacket A9 from the oil outlet A21 of the oil bath through the second heat insulation pipe A and the oil inlet 16 of the molten salt device. The silicone oil that enters the jacket A9 then enters the high-temperature circulating oil bath A1 from the oil outlet 8 of the molten salt device through the first heat insulation pipe A and the oil inlet A20 of the oil bath, so as to circulate and heat the molten salt device 2.

[0072] Step 1.3: When the temperature sensor A17 in the molten salt device 2 reaches the set temperature of the high-temperature circulating oil bath A1, the stirrer A10 stirs at a speed of 150 r / min for 30 min to obtain chlorinated molten salt.

[0073] Step 1.4: Open the second discharge valve 15 of the molten salt device 2, so that the chlorinated molten salt enters the chlorination device 4 from the molten salt output pipe 14 of the molten salt device 2 through the first pipe B and the molten salt input port 25; close the second discharge valve 15, open the first discharge valve 13, and discharge the residual chlorinated molten salt through the discharge pipe 12.

[0074] Step 2, chlorination reaction

[0075] Step 2.1: Add the solid vanadium source to the chlorination device 4 through the feed port B23, according to the molar ratio of vanadium to chlorinating agent in the solid vanadium source being 1:1.

[0076] Step 2.2: Set the temperature of the high-temperature circulating oil bath B3 to 160℃. The heated silicone oil enters the jacket B27 from the oil bath outlet B38 through the second insulation pipe B and the chlorination unit inlet 32. The silicone oil that enters the jacket B27 then enters the high-temperature circulating oil bath B3 from the chlorination unit outlet 26 through the first insulation pipe B and the oil bath inlet B37, thus circulating and heating the chlorination unit 4.

[0077] Step 2.3: When the temperature sensor B33 of the chlorination unit 4 reaches the set temperature of the high-temperature circulating oil bath B3, the stirrer B28 starts stirring at a speed of 200 r / min; at the same time, the external protective gas is input from the air inlet B24 of the chlorination unit 4, and the stirrer B28 stirs for 1 hour to obtain vanadium oxychloride gas.

[0078] Step 2.4: The vanadium oxychloride gas enters the condenser 5 from the outlet B35 of the chlorination device 4 through the second pipe B and the inlet C41; open the slag discharge valve 31 to discharge the chlorination reaction residue through the slag discharge pipe 30.

[0079] Step 3: Condensation and Collection

[0080] Step 3.1: The refrigerant is fed into the condenser 39 from the liquid inlet at the lower end of the serpentine condenser tube 47 of the condensing device 5, and then flows out from the liquid outlet at the upper end of the serpentine condenser tube 47. The flow rate of the refrigerant is 1 m / s.

[0081] Step 3.2: The vanadium oxychloride gas entering the condenser 5 enters the condenser 39 from the collection tank 44 through the outlet C45. After condensation, vanadium oxychloride liquid is obtained. The vanadium oxychloride liquid flows back into the collection tank 44 through the outlet C45. The tail gas is discharged from the tail gas collection pipe 40.

[0082] Step 3.3: Open the collection valve 43 of the condenser 5 to obtain the vanadium oxychloride liquid.

[0083] The vanadium oxychloride liquid is mixed with a solvent to obtain a vanadium-rich solution, which is used in subsequent processes.

[0084] The specific structures of the molten salt unit 2, chlorination unit 4, and condensation unit 5 in the "molten salt chlorination distillation reaction apparatus for enriching and purifying vanadium" used in this embodiment are as follows:

[0085] The molten salt device 2 is a jacketed tank with stirring, and is equipped with at least a feed port A7 at the top and at least a discharge pipe 12 and a molten salt output pipe 14 at the bottom;

[0086] The chlorination unit 4 is a jacketed tank with stirring, and the top is equipped with at least a molten salt inlet 25, a feed inlet B23 and a gas outlet B35, and the bottom is equipped with at least a slag discharge pipe 30.

[0087] Condensation device 5, connected to outlet B, is used to condense the gas evaporated from the chlorination device;

[0088] A high-temperature circulating oil bath device is used to heat the jacket of the molten salt unit and the chlorination unit respectively.

[0089] The structure of the molten salt device 2 is as follows: Figure 2 As shown: It consists of a speed controller A6, a stirrer A10, a main body A11, a temperature sensor A17, a cover plate A18, and a motor A19.

[0090] like Figure 2 As shown, the main body A11 is a double-layered cylindrical shape. A sandwich layer A9 is provided between the outer and inner walls of the main body A11. The sandwich layer A9 is filled with high-temperature silicone oil, which heats the main body A11. The port of the main body A11 is fixedly connected to the cover plate A18 by bolts, and a sealing ring is provided between the main body A11 and the cover plate A18.

[0091] like Figure 2 As shown, a feeding port A7 is provided on one side of the center of the cover plate A18, and a temperature sensor through hole A is provided on the other side of the center of the cover plate A18. The temperature measuring end of the temperature sensor A17 passes through the temperature sensor through hole A and is located in the lower part of the inner cavity of the body A11. The wiring terminal of the sensor A17 is externally connected to a speed controller A6. A stirrer through hole A is provided at the center of the cover plate A18. The lower end of the stirrer A10 passes through the stirrer through hole A and is located in the lower part of the inner cavity of the body A11. The lower end of the stirrer A10 is provided with a stirring paddle A. The upper end of the stirrer A10 is connected to the output shaft of the motor A19 through a coupling. The wiring terminal of the motor A19 is externally connected to a speed controller A6.

[0092] like Figure 2 As shown, the upper part of one side of the outer surface of the circular wall of the main body A11 is provided with an oil outlet 8 for the molten salt device, and the lower part of the other side of the outer surface of the circular wall of the main body A11 is provided with an oil inlet 16 for the molten salt device; a discharge port is provided at the center of the bottom of the main body A11, the discharge port is equipped with a discharge pipe 12 and a molten salt output pipe 14, a first discharge valve 13 is provided at the opening of the discharge pipe 12, and a second discharge valve 15 is provided at the opening of the molten salt output pipe 14.

[0093] like Figure 1 , Figure 2 and Figure 3 As shown, the oil outlet 8 of the molten salt device is connected to the oil inlet A20 of the high-temperature circulating oil bath A1 through the first heat-insulating pipe A, and the oil inlet 16 of the molten salt device is connected to the oil outlet A21 of the high-temperature circulating oil bath A1 through the second heat-insulating pipe A.

[0094] The structure of the chlorination unit 4 is as follows: Figure 4 As shown: It consists of a speed controller B36, a stirrer B28, a main body B29, a cover plate B34, a temperature sensor B33, and a motor B22.

[0095] like Figure 4 As shown, the main body B29 is a double-layered cylindrical shape, with a sandwich layer B27 between the outer and inner walls of the main body B29. The sandwich layer B27 is filled with high-temperature silicone oil, which heats the main body B29. The port of the main body B29 is fixedly connected to the cover plate B34 by bolts, and a sealing ring is provided between the main body B29 and the cover plate B34.

[0096] like Figure 4 As shown, on one side of the center of cover plate B34, from the outside to the inside, there are sequentially arranged molten salt inlet 25, air inlet B24, and feed inlet B23. On the other side of the center of cover plate B34, from the inside to the outside, there are sequentially arranged temperature sensor through hole B and air outlet B35. The temperature measuring end of temperature sensor B33 passes through the temperature sensor through hole B into the lower part of the inner cavity of body B29, and the wiring terminal of temperature sensor B33 is externally connected to speed controller B36. At the center of cover plate B34, there is a stirrer through hole B. The lower end of stirrer B28 passes through the stirrer through hole B into the lower part of the inner cavity of body B29. The lower end of stirrer B28 is equipped with a stirring paddle B. The upper end of stirrer B28 is connected to the output shaft of motor B22 through a coupling. The wiring terminal of motor B22 is externally connected to speed controller B36.

[0097] like Figure 4 As shown, the upper part of one side of the outer surface of the circular wall of the main body B29 is provided with an oil outlet 26 of the chlorination device, and the lower part of the other side of the outer surface of the circular wall of the main body B29 is provided with an oil inlet of the chlorination device; a slag discharge pipe 30 is provided at the center of the bottom of the main body B29, and a slag discharge valve 31 is provided at the pipe opening of the slag discharge pipe 30.

[0098] like Figure 1 , Figure 4 and Figure 5 As shown, the oil outlet 26 of the chlorination unit is connected to the oil inlet B37 of the high-temperature circulating oil bath B3 through the first heat-insulating pipe B, and the oil inlet 32 ​​of the chlorination unit is connected to the oil outlet B38 of the high-temperature circulating oil bath B3 through the second heat-insulating pipe B.

[0099] The structure of the condensation device 5 is as follows: Figure 6 As shown: It consists of a collection tank 44 and a condenser 39.

[0100] like Figure 6 As shown, the collection tank 44 is a hollow sphere. A collection pipe 42 is provided at the bottom of the hollow sphere, and a collection valve 43 is provided at the opening of the collection pipe 42. An air inlet C41 is provided on the left side of the hollow sphere, and an air outlet C45 is provided at the top of the hollow sphere.

[0101] like Figure 6As shown, the condenser 39 consists of a condenser tube housing 46, a serpentine condenser tube 47, and a tail gas collection pipe 40. The serpentine condenser tube 47 and the tail gas collection pipe 40 are coaxially installed inside the condenser tube housing 46. The lower port of the serpentine condenser tube 47 extends out of the lower part of the condenser tube housing 46 and serves as the liquid inlet. The upper port of the serpentine condenser tube 47 extends out of the upper part of the condenser tube housing 46 and serves as the liquid outlet. The liquid inlet is connected to the outlet pipe of the low-temperature coolant circulator, and the liquid outlet is connected to the inlet pipe of the low-temperature coolant circulator.

[0102] like Figure 6 As shown, the outlet C45 of the collection tank 44 is fixedly connected to the lower end of the condenser tube housing 46 of the condenser 39.

[0103] like Figure 1 , Figure 2 , Figure 4 and Figure 6 As shown, the molten salt output pipe 14 of the molten salt device 2 is connected to the molten salt inlet 25 of the chlorination device 4 through the first pipe B. The molten salt produced flows out from the molten salt output pipe 14 and enters the chlorination device 4 through the first pipe B from the molten salt inlet 25. The gas outlet B35 of the chlorination device 4 is connected to the gas inlet C41 of the collection tank 44 through the second pipe B. The vanadium oxychloride gas produced is output from the gas outlet B35 and enters the condensation device 5 through the second pipe B from the gas inlet C41.

[0104] In this embodiment:

[0105] The chlorinating agent is aluminum chloride.

[0106] The silicone oil is methyl silicone oil.

[0107] The solid vanadium source is obtained by oxidizing and hydrolyzing vanadium from vanadium shale leachate; the vanadium content in the solid vanadium source is 10 wt%.

[0108] The condenser is ethylene glycol; the condensation temperature of the condenser is -10℃.

[0109] The protective gas is nitrogen; the flow rate of the protective gas is 5 L / min.

[0110] The solvent is hydrochloric acid.

[0111] The vanadium oxychloride prepared in this embodiment was tested and found to have a purity of 99.917%; the calculated vanadium extraction rate was 86.3%.

[0112] Example 2

[0113] A method for enriching and purifying vanadium by molten salt chlorination distillation. This embodiment is identical to Embodiment 1 except as described below.

[0114] Step 1: Preparation of molten chloride salt

[0115] Step 1.1: Add the chlorinating agent into the molten salt device 2 through the feed port A7, according to the ratio of the volume of the chlorinating agent to the volume of the molten salt device 2 being 0.5:1.

[0116] Step 1.2: Set the temperature of the high-temperature circulating oil bath A1 to 170℃. The heated silicone oil enters the jacket A9 from the oil outlet A21 of the oil bath through the second heat insulation pipe A and the oil inlet 16 of the molten salt device. The silicone oil that enters the jacket A9 then enters the high-temperature circulating oil bath A1 from the oil outlet 8 of the molten salt device through the first heat insulation pipe A and the oil inlet A20 of the oil bath, so as to circulate and heat the molten salt device 2.

[0117] Step 1.3: When the temperature sensor A17 in the molten salt device 2 reaches the set temperature of the high-temperature circulating oil bath A1, the stirrer A10 stirs at a speed of 250 r / min for 40 min to obtain chlorinated molten salt.

[0118] Step 1.4: Open the second discharge valve 15 of the molten salt device 2, so that the chlorinated molten salt enters the chlorination device 4 from the molten salt output pipe 14 of the molten salt device 2 through the first pipe B and the molten salt input port 25; close the second discharge valve 15, open the first discharge valve 13, and discharge the residual chlorinated molten salt through the discharge pipe 12.

[0119] Step 2, chlorination reaction

[0120] Step 2.1: Add the solid vanadium source to the chlorination device 4 through the feed port B23, according to the molar ratio of vanadium to chlorinating agent in the solid vanadium source being 1:2.

[0121] Step 2.2: Set the temperature of the high-temperature circulating oil bath B3 to 170℃. The heated silicone oil enters the jacket B27 from the oil bath outlet B38 through the second insulation pipe B and the chlorination unit inlet 32. The silicone oil that enters the jacket B27 then enters the high-temperature circulating oil bath B3 from the chlorination unit outlet 26 through the first insulation pipe B and the oil bath inlet B37, thus circulating and heating the chlorination unit 4.

[0122] Step 2.3: When the temperature sensor B33 of the chlorination unit 4 reaches the set temperature of the high-temperature circulating oil bath B3, the stirrer B28 starts stirring at a speed of 350 r / min; at the same time, the external protective gas is input from the air inlet B24 of the chlorination unit 4, and the stirrer B28 stirs for 1.5 hours to obtain vanadium oxychloride gas.

[0123] Step 2.4: The vanadium oxychloride gas enters the condenser 5 from the outlet B35 of the chlorination device 4 through the second pipe B and the inlet C41; open the slag discharge valve 31 to discharge the chlorination reaction residue through the slag discharge pipe 30.

[0124] Step 3: Condensation and Collection

[0125] Step 3.1: The refrigerant is fed into the condenser 39 from the liquid inlet at the lower end of the serpentine condenser tube 47 of the condensing device 5, and then flows out from the liquid outlet at the upper end of the serpentine condenser tube 47. The flow rate of the refrigerant is 2m / s.

[0126] Step 3.2: The vanadium oxychloride gas entering the condenser 5 enters the condenser 39 from the collection tank 44 through the outlet C45. After condensation, vanadium oxychloride liquid is obtained. The vanadium oxychloride liquid flows back into the collection tank 44 through the outlet C45. The tail gas is discharged from the tail gas collection pipe 40.

[0127] Step 3.3: Open the collection valve 43 of the condenser 5 to obtain the vanadium oxychloride liquid.

[0128] The vanadium oxychloride liquid is mixed with a solvent to obtain a vanadium-rich solution, which is used in subsequent processes.

[0129] In this embodiment:

[0130] The chlorinating agent is a mixture of aluminum chloride and sodium chloride.

[0131] The silicone oil is phenyl silicone oil.

[0132] The solid vanadium source is obtained by oxidizing and hydrolyzing vanadium from vanadium shale leachate; the vanadium content in the solid vanadium source is 13 wt%.

[0133] The condenser is ethylene glycol; the condensation temperature of the condenser is 0°C.

[0134] The protective gas is argon; the flow rate of the protective gas is 10 L / min.

[0135] The solvent is water.

[0136] The vanadium oxychloride obtained in this embodiment was tested and found to have a purity of 99.923%; the calculated vanadium extraction rate was 88.1%.

[0137] Example 3

[0138] A method for enriching and purifying vanadium by molten salt chlorination distillation. This embodiment is identical to Embodiment 1 except as described below.

[0139] Step 1: Preparation of molten chloride salt

[0140] Step 1.1: Add the chlorinating agent into the molten salt device 2 through the feed port A7, according to the ratio of the volume of the chlorinating agent to the volume of the molten salt device 2 being 0.7:1.

[0141] Step 1.2: Set the temperature of the high-temperature circulating oil bath A1 to 210℃. The heated silicone oil enters the jacket A9 from the oil outlet A21 of the oil bath through the second heat insulation pipe A and the oil inlet 16 of the molten salt device. The silicone oil that enters the jacket A9 then enters the high-temperature circulating oil bath A1 from the oil outlet 8 of the molten salt device through the first heat insulation pipe A and the oil inlet A20 of the oil bath, so as to circulate and heat the molten salt device 2.

[0142] Step 1.3: When the temperature sensor A17 in the molten salt device 2 reaches the set temperature of the high-temperature circulating oil bath A1, the stirrer A10 stirs at a speed of 400 r / min for 50 min to obtain chlorinated molten salt.

[0143] Step 1.4: Open the second discharge valve 15 of the molten salt device 2, so that the chlorinated molten salt enters the chlorination device 4 from the molten salt output pipe 14 of the molten salt device 2 through the first pipe B and the molten salt input port 25; close the second discharge valve 15, open the first discharge valve 13, and discharge the residual chlorinated molten salt through the discharge pipe 12.

[0144] Step 2, chlorination reaction

[0145] Step 2.1: Add the solid vanadium source to the chlorination device 4 through the feed port B23, according to the molar ratio of vanadium to chlorinating agent in the solid vanadium source being 1:3.

[0146] Step 2.2: Set the temperature of the high-temperature circulating oil bath B3 to 180℃. The heated silicone oil enters the jacket B27 from the oil outlet B38 of the oil bath through the second insulation pipe B and the oil inlet 32 ​​of the chlorination unit. The silicone oil that enters the jacket B27 then enters the high-temperature circulating oil bath B3 from the oil outlet 26 of the chlorination unit through the first insulation pipe B and the oil inlet B37 of the oil bath, so as to circulate and heat the chlorination unit 4.

[0147] Step 2.3: When the temperature sensor B33 of the chlorination unit 4 reaches the set temperature of the high-temperature circulating oil bath B3, the stirrer B28 starts stirring at a speed of 500 r / min; at the same time, the external protective gas is input from the air inlet B24 of the chlorination unit 4, and the stirrer B28 stirs for 2 hours to obtain vanadium oxychloride gas.

[0148] Step 2.4: The vanadium oxychloride gas enters the condenser 5 from the outlet B35 of the chlorination device 4 through the second pipe B and the inlet C41; open the slag discharge valve 31 to discharge the chlorination reaction residue through the slag discharge pipe 30.

[0149] Step 3: Condensation and Collection

[0150] Step 3.1: The refrigerant is fed into the condenser 39 from the liquid inlet at the lower end of the serpentine condenser tube 47 of the condensing device 5, and then flows out from the liquid outlet at the upper end of the serpentine condenser tube 47. The flow rate of the refrigerant is 3m / s.

[0151] Step 3.2: The vanadium oxychloride gas entering the condenser 5 enters the condenser 39 from the collection tank 44 through the outlet C45. After condensation, vanadium oxychloride liquid is obtained. The vanadium oxychloride liquid flows back into the collection tank 44 through the outlet C45. The tail gas is discharged from the tail gas collection pipe 40.

[0152] Step 3.3: Open the collection valve 43 of the condenser 5 to obtain the vanadium oxychloride liquid.

[0153] The vanadium oxychloride liquid is mixed with a solvent to obtain a vanadium-rich solution, which is used in subsequent processes.

[0154] In this embodiment:

[0155] The chlorinating agent is a mixture of aluminum chloride and sodium chloride.

[0156] The silicone oil is methyl silicone oil.

[0157] The solid vanadium source is obtained by oxidizing and hydrolyzing vanadium from vanadium shale leachate; the vanadium content in the solid vanadium source is 15 wt%.

[0158] The condenser is ethanol; the condensation temperature of the condenser is 10°C.

[0159] The protective gas is nitrogen; the flow rate of the protective gas is 15 L / min.

[0160] The solvent is sulfuric acid.

[0161] The vanadium oxychloride obtained in this embodiment was tested and found to have a purity of 99.945%; the calculated vanadium extraction rate was 87.5%.

[0162] Example 4

[0163] A method for enriching and purifying vanadium by molten salt chlorination distillation. This embodiment is identical to Embodiment 1 except as described below.

[0164] Step 1: Preparation of molten chloride salt

[0165] Step 1.1: Add the chlorinating agent into the molten salt device 2 through the feed port A7 of the molten salt device 2 according to the ratio of the volume of the chlorinating agent to the volume of the molten salt device 2 being 0.8:1.

[0166] Step 1.2: Set the temperature of the high-temperature circulating oil bath A1 to 250℃. The heated silicone oil enters the jacket A9 from the oil outlet A21 of the oil bath through the second heat insulation pipe A and the oil inlet 16 of the molten salt device. The silicone oil that enters the jacket A9 then enters the high-temperature circulating oil bath A1 from the oil outlet 8 of the molten salt device through the first heat insulation pipe A and the oil inlet A20 of the oil bath, so as to circulate and heat the molten salt device 2.

[0167] Step 1.3: When the temperature sensor A17 in the molten salt device 2 reaches the set temperature of the high-temperature circulating oil bath A1, the stirrer A10 stirs at a speed of 500 r / min for 60 min to obtain chlorinated molten salt.

[0168] Step 1.4: Open the second discharge valve 15 of the molten salt device 2, so that the chlorinated molten salt enters the chlorination device 4 from the molten salt output pipe 14 of the molten salt device 2 through the first pipe B and the molten salt input port 25; close the second discharge valve 15, open the first discharge valve 13, and discharge the residual chlorinated molten salt through the discharge pipe 12.

[0169] Step 2, chlorination reaction

[0170] Step 2.1: Add the solid vanadium source to the chlorination device 4 through the feed port B23, according to the molar ratio of vanadium to chlorinating agent in the solid vanadium source being 1:4.

[0171] Step 2.2: Set the temperature of the high-temperature circulating oil bath B3 to 200℃. The heated silicone oil enters the jacket B27 from the oil outlet B38 of the oil bath through the second insulation pipe B and the oil inlet 32 ​​of the chlorination unit. The silicone oil that enters the jacket B27 then enters the high-temperature circulating oil bath B3 from the oil outlet 26 of the chlorination unit through the first insulation pipe B and the oil inlet B37 of the oil bath, so as to circulate and heat the chlorination unit 4.

[0172] Step 2.3: When the temperature sensor B33 of the chlorination unit 4 reaches the set temperature of the high-temperature circulating oil bath B3, the stirrer B28 starts stirring at a speed of 600 r / min; at the same time, the external protective gas is input from the air inlet B24 of the chlorination unit 4, and the stirrer B28 stirs for 3 hours to obtain vanadium oxychloride gas.

[0173] Step 2.4: The vanadium oxychloride gas enters the condenser 5 from the outlet B35 of the chlorination device 4 through the second pipe B and the inlet C41; open the slag discharge valve 31 to discharge the chlorination reaction residue through the slag discharge pipe 30.

[0174] Step 3: Condensation and Collection

[0175] Step 3.1: The refrigerant is fed into the condenser 39 from the liquid inlet at the lower end of the serpentine condenser tube 47 of the condensing device 5, and then flows out from the liquid outlet at the upper end of the serpentine condenser tube 47. The flow rate of the refrigerant is 4 m / s.

[0176] Step 3.2: The vanadium oxychloride gas entering the condenser 5 enters the condenser 39 from the collection tank 44 through the outlet C45. After condensation, vanadium oxychloride liquid is obtained. The vanadium oxychloride liquid flows back into the collection tank 44 through the outlet C45. The tail gas is discharged from the tail gas collection pipe 40.

[0177] Step 3.3: Open the collection valve 43 of the condenser 5 to obtain the vanadium oxychloride liquid.

[0178] The vanadium oxychloride liquid is mixed with a solvent to obtain a vanadium-rich solution, which is used in subsequent processes.

[0179] In this embodiment:

[0180] The chlorinating agent is a mixture of aluminum chloride and zinc chloride.

[0181] The silicone oil is phenyl silicone oil.

[0182] The solid vanadium source is obtained by oxidizing and hydrolyzing vanadium from vanadium shale leachate; the vanadium content in the solid vanadium source is 18 wt%.

[0183] The condenser is water; the condensation temperature of the condenser is 20°C.

[0184] The protective gas is argon; the flow rate of the protective gas is 20 L / min.

[0185] The solvent is water.

[0186] The vanadium oxychloride prepared in this embodiment was tested and found to have a purity of 99.931%; the calculated vanadium extraction rate was 86.8%.

[0187] This specific implementation method has the following advantages compared with the prior art:

[0188] 1. This specific embodiment uses a molten salt chlorination distillation reactor to enrich and purify vanadium. Compared with existing solvent extraction and ion exchange methods, after oxidation-hydrolysis precipitation of vanadium in vanadium shale leachate, a single-stage chlorination distillation process can produce vanadium oxychloride liquid with a purity ≥99.9%. This eliminates the need for multi-stage continuous processes, resulting in a shorter process flow and better vanadium impurity separation. Therefore, the obtained vanadium oxychloride has high purity, and the further obtained vanadium pentoxide product has a purity ≥99.9%.

[0189] 2. This specific embodiment uses low-temperature molten salt as the chlorinating agent, which destroys the structure of the solid vanadium source through wetting, thereby releasing vanadium. The reaction temperature is 160-200℃, which is more environmentally friendly than using chlorine gas as the chlorinating agent, and the process has high controllability and good safety.

[0190] 3. The "molten salt chlorination distillation reactor for enriching and purifying vanadium" adopted in this specific embodiment is a multi-functional integrated structure, integrating the molten salt device 2, the chlorination device 4, and the condensation device 5 into one unit. Compared with the existing series-connected reactors, this specific embodiment reduces the number of pipelines and valves used, making it less prone to leakage of vanadium oxychloride gas and ensuring high safety. In addition, compared with the integrated chlorination reactor in the prior art, the molten salt device 2 and the chlorination device 4 can also prevent some chlorides from volatilizing due to heat during the preparation of molten salt, preventing the volatilized chlorides from adhering to the inner wall of the chlorination device 4 and entering the vanadium oxychloride gas, thereby effectively inhibiting the reduction of the purity of the reaction product. Stirrers A10 and B28 are respectively installed in the molten salt device 2 and the chlorination device 4. Stirrers A10 and B28 increase the contact area between molten salts and between the solid vanadium source and the molten salt, improving the molten salt preparation efficiency and chlorination efficiency, with a vanadium extraction rate of over 85%.

[0191] Therefore, this specific implementation method has the characteristics of short process flow, good vanadium impurity separation effect, environmental friendliness, high process controllability, good safety and high chlorination efficiency. The vanadium oxychloride liquid prepared by this method has high purity.

Claims

1. A method for enriching and purifying vanadium by molten salt chlorination distillation, characterized in that, The method for enriching and purifying vanadium by molten salt chlorination distillation uses a "molten salt chlorination distillation reaction device for enriching and purifying vanadium", which includes a molten salt device (2), a chlorination device (4), a condensation device (5), a high-temperature circulating oil bath A (1), and a high-temperature circulating oil bath B (3). The method for enriching and purifying vanadium by molten salt chlorination distillation is as follows: Step 1: Preparation of chlorinated molten salt. Chlorinating agent is added to molten salt device (2). Molten salt device (2) is heated in an oil bath. The heating temperature is set to 130~250℃. The reaction is carried out under stirring to obtain chlorinated molten salt. Step 2, chlorination reaction: Add molten chlorinated salt and solid vanadium source to chlorination device (4), heat chlorination device (4) in an oil bath, set the heating temperature to 160~200℃, react under stirring to obtain vanadium oxychloride gas; Step 3: Condensation and collection. The obtained vanadium oxychloride gas is introduced into the condensation device (5) and condensed using the condensation device (5) to collect the vanadium oxychloride liquid. Step 1 is as follows: Step 1.1: According to the ratio of the volume of chlorinating agent to the volume of molten salt device (2) being 0.3~0.8:1, add the chlorinating agent into the molten salt device (2) through the feed port A (7) of the molten salt device (2); Step 1.2: Set the temperature of the high-temperature circulating oil bath A (1) to 130~250℃. The heated silicone oil enters the jacket A (9) from the oil bath outlet A (21) through the second heat insulation pipe A and the oil inlet (16) of the molten salt device. The silicone oil that enters the jacket A (9) then enters the high-temperature circulating oil bath A (1) from the oil bath outlet A (8) through the first heat insulation pipe A and the oil inlet A (20) of the oil bath device to circulate and heat the molten salt device (2). Step 1.3: When the temperature sensor A (17) in the molten salt device (2) reaches the set temperature of the high temperature circulating oil bath A (1), the stirrer A (10) stirs at a speed of 150~500r / min for 30~60min to obtain chlorinated molten salt. Step 1.4: Open the second discharge valve (15) of the molten salt device (2) so that the chlorinated molten salt enters the chlorination device (4) from the molten salt output pipe (14) of the molten salt device (2) through the first pipe B and the molten salt input port (25).

2. The method for enriching and purifying vanadium by molten salt chlorination distillation according to claim 1, characterized in that, Step 2 is as follows: Step 2.1: According to the molar ratio of vanadium to chlorinating agent in the solid vanadium source being 1:1~4, the solid vanadium source is added to the chlorination device (4) through the feed port B (23). Step 2.2: Set the temperature of the high-temperature circulating oil bath B(3) to 160~200℃. The heated silicone oil enters the jacket B(27) from the oil bath outlet B(38) through the second heat insulation pipe B from the chlorination unit inlet (32). The silicone oil that enters the jacket B(27) then enters the high-temperature circulating oil bath B(3) from the chlorination unit outlet (26) through the first heat insulation pipe B from the oil bath inlet B(37) to circulate and heat the chlorination unit (4). Step 2.3: When the temperature sensor B (33) of the chlorination device (4) reaches the set temperature of the high-temperature circulating oil bath B (3), the stirrer B (28) starts stirring at a speed of 200~600r / min; at the same time, the external protective gas is input from the air inlet B (24) of the chlorination device (4), and the stirrer B (28) stirs for 1~3 hours to obtain vanadium oxychloride gas; Step 2.4: The vanadium oxychloride gas enters the condenser (5) from the outlet B (35) of the chlorination device (4) through the second pipe B and the inlet C (41).

3. The method for enriching and purifying vanadium by molten salt chlorination distillation according to claim 1, characterized in that, Step 3 is as follows: Step 3.1: The refrigerant is fed into the condenser (39) from the liquid inlet at the lower end of the serpentine condenser tube (47) of the condensing device (5), and then flows out from the liquid outlet at the upper end of the serpentine condenser tube (47). The flow rate of the refrigerant is 1~4m / s. Step 3.2: The vanadium trichloride gas entering the condenser (5) enters the condenser (39) from the collection tank (44) through the outlet C (45), and after condensation, vanadium trichloride liquid is obtained. The vanadium trichloride liquid flows back into the collection tank (44) through the outlet C (45). Step 3.3: Open the collection valve (43) of the condenser (5) to obtain the vanadium oxychloride liquid.

4. The method for enriching and purifying vanadium by molten salt chlorination distillation according to claim 1, characterized in that: The specific structures of the molten salt device (2), chlorination device (4), condensation device (5), high-temperature circulating oil bath A (1), and high-temperature circulating oil bath B (3) are as follows: The molten salt device (2) consists of a speed regulator A (6), a stirrer A (10), a body A (11), a temperature sensor A (17), a cover plate A (18), and a motor A (19); The main body A (11) is a double-layered cylindrical shape. A sandwich layer A (9) is provided between the outer wall and the inner wall of the main body A (11). The sandwich layer A (9) is filled with high-temperature silicone oil, which heats the main body A (11). The port of the main body A (11) is fixedly connected to the cover plate A (18) by bolts. A sealing ring is provided between the main body A (11) and the cover plate A (18). A feeding port A (7) is provided on one side of the center of the cover plate A (18), and a temperature sensor through hole A is provided on the other side of the center of the cover plate A (18); the temperature measuring end of the temperature sensor A (17) passes through the temperature sensor through hole A and is located in the lower part of the inner cavity of the body A (11), and the wiring terminal of the sensor A (17) is connected to the speed regulator A (6); a stirrer through hole A is provided at the center of the cover plate A (18), and the lower end of the stirrer A (10) passes through the stirrer through hole A and is located in the lower part of the inner cavity of the body A (11). The lower end of the stirrer A (10) is provided with a stirring paddle A, and the upper end of the stirrer A (10) is connected to the output shaft of the motor A (19) through a coupling. The wiring terminal of the motor A (19) is connected to the speed regulator A (6). The upper part of one side of the outer surface of the circular wall of the main body A (11) is provided with an oil outlet (8) for the molten salt device, and the lower part of the other side of the outer surface of the circular wall of the main body A (11) is provided with an oil inlet (16) for the molten salt device; the bottom center of the main body A (11) is provided with a discharge port, which is equipped with a discharge pipe (12) and a molten salt output pipe (14). The discharge pipe (12) is provided with a first discharge valve (13) at the pipe opening, and the molten salt output pipe (14) is provided with a second discharge valve (15) at the pipe opening; The oil outlet (8) of the molten salt device is connected to the oil inlet A (20) of the high-temperature circulating oil bath A (1) through the first heat insulation pipe A, and the oil inlet (16) of the molten salt device is connected to the oil outlet A (21) of the high-temperature circulating oil bath A (1) through the second heat insulation pipe A. The chlorination device (4) consists of a speed regulator B (36), a stirrer B (28), a body B (29), a cover plate B (34), a temperature sensor B (33), and a motor B (22); The main body B (29) is a double-layered cylindrical shape. A sandwich layer B (27) is provided between the outer wall and the inner wall of the main body B (29). The sandwich layer B (27) is filled with high-temperature silicone oil, which heats the main body B (29). The port of the main body B (29) is fixedly connected to the cover plate B (34) by bolts. A sealing ring is provided between the main body B (29) and the cover plate B (34). A molten salt inlet (25), an air inlet (24), and a feed inlet (23) are arranged sequentially from the outside to the inside on one side of the center of the cover plate B (34). A temperature sensor through hole B and an air outlet B (35) are arranged sequentially from the inside to the outside on the other side of the center of the cover plate B (34). The temperature measuring end of the temperature sensor B (33) passes through the temperature sensor through hole B and is located in the lower part of the inner cavity of the body B (29). The wiring terminal of the temperature sensor B (33) is connected to a speed regulator B (36). A stirrer through hole B is provided at the center of the cover plate B (34). The lower end of the stirrer B (28) passes through the stirrer through hole B and is located in the lower part of the inner cavity of the body B (29). A stirring paddle B is provided at the lower end of the stirrer B (28). The upper end of the stirrer B (28) is connected to the output shaft of the motor B (22) through a coupling. The wiring terminal of the motor B (22) is connected to a speed regulator B (36). The upper part of one side of the outer surface of the circular wall of the main body B (29) is provided with an oil outlet (26) of the chlorination device, and the lower part of the other side of the outer surface of the circular wall of the main body B (29) is provided with an oil inlet (32) of the chlorination device; a slag discharge pipe (30) is provided at the bottom center of the main body B (29), and a slag discharge valve (31) is provided at the pipe opening of the slag discharge pipe (30). The chlorination unit's oil outlet (26) is connected to the oil bath inlet B (37) of the high-temperature circulating oil bath B (3) through the first heat-insulating pipe B, and the chlorination unit's oil inlet (32) is connected to the oil bath outlet B (38) of the high-temperature circulating oil bath B (3) through the second heat-insulating pipe B. The condensation device (5) consists of a collection tank (44) and a condenser (39); The collection tank (44) is a hollow sphere. A collection pipe (42) is provided at the bottom of the hollow sphere. A collection valve (43) is provided at the opening of the collection pipe (42). An air inlet C (41) is provided on the left side of the hollow sphere. An air outlet C (45) is provided at the top of the hollow sphere. The condenser (39) consists of a condenser shell (46), a serpentine condenser (47), and a tail gas collection pipe (40). The serpentine condenser (47) and the tail gas collection pipe (40) are coaxially installed inside the condenser shell (46). The lower end of the serpentine condenser (47) extends out of the lower part of the condenser shell (46) and is the liquid inlet. The upper end of the serpentine condenser (47) extends out of the upper part of the condenser shell (46) and is the liquid outlet. The liquid inlet is connected to the outlet pipe of the low-temperature coolant circulator, and the liquid outlet is connected to the inlet pipe of the low-temperature coolant circulator. The outlet C (45) of the collection tank (44) is fixedly connected to the lower end of the condenser tube shell (46) of the condenser (39); The molten salt output pipe (14) of the molten salt device (2) is connected to the molten salt input port (25) of the chlorination device (4) through the first pipe B. The molten salt produced is output from the molten salt output pipe (14) and enters the chlorination device (4) through the first pipe B from the molten salt input port (25). The gas outlet B (35) of the chlorination device (4) is connected to the gas inlet C (41) of the collection tank (44) through the second pipe B. The vanadium oxychloride gas produced is output from the gas outlet B (35) and enters the condensation device (5) through the second pipe B from the gas inlet C (41).

5. The method for enriching and purifying vanadium by molten salt chlorination distillation according to claim 1, characterized in that... The chlorinating agent is aluminum chloride, or a mixture of aluminum chloride and sodium chloride, or a mixture of aluminum chloride and zinc chloride.

6. The method for enriching and purifying vanadium by molten salt chlorination distillation according to claim 1, characterized in that... The silicone oil is methyl silicone oil or phenyl silicone oil.

7. The method for enriching and purifying vanadium by molten salt chlorination distillation according to claim 1, characterized in that... The solid vanadium source is obtained by oxidizing and hydrolyzing vanadium from vanadium shale leachate; the vanadium content in the solid vanadium source is ≥10wt%.

8. The method for enriching and purifying vanadium by molten salt chlorination distillation according to claim 2, characterized in that... The protective gas is nitrogen or argon; the flow rate of the protective gas is 5~20 L / min.

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