Method for enriching and purifying vanadium through fused salt chlorination rectification

Abstract

The invention relates to a method for enriching and purifying vanadium through fused salt chlorination rectification. The technical scheme is as follows: the vanadium is enriched and purified by adopting a molten salt chlorination rectification reaction device for enriching and purifying the vanadium. The method specifically comprises the following steps: adding a chlorinating agent into a molten salt device (2), heating and stirring, outputting the prepared chlorinated molten salt from a molten salt output pipe (14) through a second discharge valve (15), and entering a chlorination device (4) from a molten salt input port (25) through a first pipeline B; a solid vanadium source added into the chlorination device (4) is mixed with the chlorinated fused salt, and heating and stirring are performed to generate vanadium oxytrichloride gas; vanadium oxytrichloride gas is discharged from a gas outlet B (35) and enters a condensing device (5) from a gas inlet C (41) through a second pipeline B; and condensing in a condenser (39) to obtain vanadium oxytrichloride liquid, and collecting the vanadium oxytrichloride liquid through a collecting tank (44). The method 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 prepared vanadium oxytrichloride liquid is high in purity.

Description

Technical Field

[0001] The invention belongs to the technical field of enriching and purifying vanadium, and specifically relates to a method for enriching and purifying vanadium by molten salt chlorination distillation. Background Art

[0002] Vanadium is an important metal with strategic significance and is widely distributed in nature. Among them, vanadium shale is an important vanadium ore resource. Direct acid leaching is often used to extract vanadium from vanadium shale. However, due to the complex mineral composition and low vanadium content in vanadium shale, a large amount of impurity elements enter the leachate during the vanadium extraction process. Therefore, the enrichment and purification of vanadium shale leachate is of great significance for the preparation of vanadium products. At present, solvent extraction, ion exchange and other methods can be used to enrich and purify vanadium in vanadium shale leachate.

[0003] The patented technology of "method for extracting vanadium from vanadium-containing solution" (CN109306404B) is to separate sulfuric acid from vanadium-containing solution by countercurrent extraction with organic phase A containing amine extractant to obtain extract stock solution and loaded organic phase A, countercurrent extraction with organic phase B containing phosphorus extractant to obtain raffinate and loaded organic phase B, and back-extract loaded organic phase B with aqueous sulfuric acid as back-extractant to obtain lean organic phase B and vanadium-rich solution. Although this technology can achieve vanadium enrichment and purification, the two-stage countercurrent extraction requires 2 to 6 stages and 3 to 5 stages respectively, the process flow is long, and the purity of the obtained vanadium pentoxide product is 99%, which is low.

[0004] The patented technology of "A method for extracting vanadium from hydrodesulfurization waste catalyst using anion exchange resin" (CN117587267A) uses sulfuric acid solution to leach the ground hydrodesulfurization waste catalyst powder, and uses anion exchange resin to adsorb vanadium compounds in the pentavalent vanadium leachate after oxidation and neutralization of the leachate; and uses a desorbent to desorb the anion exchange resin after adsorbing the vanadium compounds to obtain a vanadium ion-enriched solution. Although this technology achieves vanadium enrichment and purification, the obtained vanadium ion-enriched solution still contains 5% iron ions, and the vanadium impurity separation effect is poor.

[0005] The patented technology of "a method for preparing refined vanadium trichloride using vanadium-containing refined tailings" (CN115947370A) uses vanadium-containing refined tailings as raw materials, performs high-temperature treatment under inert gas to obtain pre-treated refined tailings, and continuously introduces a mixed gas of oxygen and chlorine after cooling to react. After the reaction, the mixed gas is discharged and condensed at low temperature to obtain vanadium trichloride liquid; although this technology can achieve vanadium enrichment and purification, the required chlorination temperature is relatively high, resulting in some impurities being chlorinated at the same time, and a purification process needs to be added later; chlorine is used as a chlorinating agent, which pollutes the environment, has low process controllability, and poor safety.

[0006] The document (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 monochloride. The process uses industrial-grade vanadium pentoxide as raw material, aluminum chloride and sodium chloride as chlorinating agents, and obtains high-purity vanadium trichloride by low-temperature chlorination in a traditional small-scale distillation series reaction device to achieve vanadium enrichment and purification; however, the traditional small-scale distillation series reaction device used in the process is difficult to use industrially. The series connection of multiple independent devices such as distillation flasks, condensers, receiving tanks, and tail gas treatment equipment requires longer pipelines and more valve connections, which increases the risk of leakage of vanadium trichloride and has poor safety; the equipment is not equipped with a stirring device, which will lead to a decrease in chlorination efficiency, a vanadium extraction rate of 75%, and an insufficient reaction.

[0007] In summary, the existing methods for enriching and purifying vanadium have the problems of long process flow, poor vanadium impurity separation effect, environmental unfriendliness, low process controllability, poor safety, low chlorination efficiency and low purity. Summary of the invention

[0008] The present invention aims to overcome the defects of the prior art and aims to provide a method for enriching and purifying vanadium by molten salt chlorination distillation, which 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 trichloride liquid prepared by the method has high purity.

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

[0010] A method for enriching and purifying vanadium by molten salt chlorination distillation, wherein the method for enriching and purifying vanadium by molten salt chlorination distillation adopts a "molten salt chlorination distillation reaction device for enriching and purifying vanadium", and the device comprises 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:

[0012] Step 1, preparation of chloride molten salt, adding a chlorinating agent into a molten salt device, heating the molten salt device in an oil bath, setting the heating temperature to 130-250° C., reacting under stirring conditions to obtain chloride molten salt;

[0013] Step 2, chlorination reaction, adding molten chloride and solid vanadium source into a chlorination device, heating the chlorination device in an oil bath, setting the heating temperature to 160-200° C., reacting under stirring conditions to obtain vanadium trichloride gas;

[0014] Step 3: Condensation and collection: introducing the obtained vanadium oxychloride gas into a condensation device, condensing the vanadium oxychloride gas by using the condensation device, and collecting the vanadium oxychloride liquid.

[0015] Step 1 is as follows:

[0016] Step 1.1, adding 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 of 0.3-0.8:1.

[0017] Step 1.2, set the temperature of the high-temperature circulating oil bath A to 130-250°C, and the heated silicone oil enters the interlayer A from the oil outlet A of the oil bath through the second insulation tube A from the oil inlet of the molten salt device, and the silicone oil entering the interlayer A enters the high-temperature circulating oil bath A from the oil outlet of the molten salt device through the first insulation tube 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 to 500 r / min for 30 to 60 min to obtain chlorinated molten salt.

[0019] Step 1.4, open the second discharge valve of the molten salt device, so that the chlorinated molten salt enters the chlorination device from the molten salt output pipe of the molten salt device through the first pipeline B and the molten salt input port; close the second discharge valve, open the first discharge valve, and discharge the residual chlorinated molten salt through the discharge pipe.

[0020] The details of step 2 are as follows:

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

[0022] Step 2.2, set the temperature of the high-temperature circulating oil bath B to 160-200°C, and the heated silicone oil enters the interlayer B from the oil outlet B of the oil bath through the second insulation pipe B from the oil inlet of the chlorination device, and the silicone oil entering the interlayer B enters the high-temperature circulating oil bath B from the oil outlet of the chlorination device through the first insulation pipe B from the oil inlet B of the oil bath to circulate and heat the chlorination device.

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

[0024] Step 2.4, the vanadium oxychloride gas enters the condensing device from the gas outlet B of the chlorination device through the second pipeline B and the gas inlet C; open the slag discharge valve to discharge the chlorination reaction residue through the slag discharge pipe.

[0025] The details of step 3 are as follows:

[0026] Step 3.1, input the condensing agent into the condenser from the liquid inlet at the lower end of the serpentine condensing tube of the condensing device, and then flow out from the liquid outlet at the upper end of the serpentine condensing tube, and the flow rate of the condensing agent is 1-4m / s.

[0027] Step 3.2: the vanadium trichloride gas entering the condensing device enters the condenser from the collecting tank through the gas outlet C, and condenses to obtain vanadium trichloride liquid, which flows back into the collecting tank through the gas outlet C; the tail gas is discharged from the tail gas collection pipe.

[0028] Step 3.3, opening the collecting valve of the condensing device to obtain the vanadium oxychloride liquid.

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

[0030] A molten salt chlorination distillation reaction device for enriching and purifying vanadium, comprising

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

[0032] The chlorination device is a sandwich tank with stirring, the top of which is equipped with at least a molten salt input port, a feed port B and a gas outlet B, and the bottom is equipped with at least a slag discharge pipe;

[0033] The condensation device is connected to the gas outlet B and is used to condense the gas evaporated from the chlorination device; the high-temperature circulating oil bath device is used to perform oil bath heating on the interlayers of the molten salt device and the chlorination device respectively.

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

[0035] The body A is a double-layer cylinder, and an interlayer A is provided between the outer wall and the inner wall of the body A. The interlayer A is filled with high-temperature silicone oil, and the high-temperature silicone oil heats the body A. The port of the body A is fixedly connected to the cover plate A by bolts, and a sealing ring is provided between the body A and the cover plate A.

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

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

[0038] The chlorination device is composed of a speed regulator B, a stirrer B, a body B, a cover plate B, a temperature sensor B and a motor B.

[0039] The body B is a double-layer cylinder, with an interlayer B between the outer wall and the inner wall of the body B, and high-temperature silicone oil is contained in the interlayer B, which heats the body B. The port of the body B is fixedly connected to the cover plate B by bolts, and a sealing ring is provided between the body B and the cover plate B.

[0040] One side of the center of the cover plate B is provided with a molten salt input port, an air inlet B and a feed port B in sequence from outside to inside, and the other side of the center of the cover plate B is provided with a temperature sensor through hole B and an air outlet B in sequence from inside to outside; the temperature measuring end of the temperature sensor B passes through the temperature sensor through hole B at the lower part of the inner cavity of the body B, and the wiring terminal of the temperature sensor B is externally connected to the speed regulator B. A stirrer through hole B is provided at the center of the cover plate B, the lower end of the stirrer B passes through the stirrer through hole B at the lower part of the inner cavity of the body B, a stirring paddle B is provided at the lower end of the stirrer B, the upper end of the stirrer B is connected to the output shaft of the motor B through a coupling, and the wiring terminal of the motor B is externally connected to the speed regulator B.

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

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

[0043] The condensing device consists of a collecting tank and a condenser.

[0044] The collecting tank is a hollow sphere, a collecting pipe is arranged at the bottom of the hollow sphere, a collecting valve is arranged at the pipe mouth of the collecting pipe, an air inlet C is arranged on the left side of the hollow sphere, and an air outlet C is arranged on the upper part of the hollow sphere.

[0045] The condenser consists of a condenser tube shell, a serpentine condenser tube and an exhaust gas collecting tube, wherein the serpentine condenser tube and the exhaust gas collecting tube are coaxially installed in the condenser tube shell; the lower port of the serpentine condenser tube passes through the lower part of the condenser tube shell, and the lower port of the serpentine condenser tube is the liquid inlet, and the upper port of the serpentine condenser tube passes through the upper part of the condenser tube shell, and the upper port of the serpentine condenser tube is the liquid outlet; the liquid inlet is externally connected to the liquid outlet pipe of the low-temperature coolant circulator, and the liquid outlet is externally connected to the liquid inlet pipe of the low-temperature coolant circulator.

[0046] The gas outlet C of the collecting 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 device is connected with the molten salt input port of the chlorination device through the first pipeline B, and the prepared molten salt is output from the molten salt output pipe and enters the chlorination device from the molten salt input port through the first pipeline B; the gas outlet B of the chlorination device is connected with the gas inlet C of the collection tank through the second pipeline B, and the prepared vanadium trichloride gas is output from the gas outlet B and enters the condensation device from the gas inlet C through the second pipeline B.

[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 prepared by oxidizing and then hydrolyzing vanadium from vanadium shale leaching solution; the vanadium content in the solid vanadium source is ≥10wt%.

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

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

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

[0054] Due to the adoption of the above technical solution, the present invention has the following positive effects compared with the prior art:

[0055] 1. The present invention adopts a molten salt chlorination distillation reaction device for enriching and purifying vanadium to enrich and purify vanadium. Compared with the existing solvent extraction method and ion exchange method, after the vanadium shale leachate is oxidized-hydrolyzed to precipitate vanadium, a vanadium trichloride liquid with a purity of ≥99.9% can be obtained through a single-stage chlorination distillation process. No multi-stage continuous process is required, the process flow is short, and the vanadium impurity separation effect is good; therefore, the obtained vanadium trichloride has high purity, and the purity of the further obtained vanadium pentoxide product is ≥99.9%.

[0056] 2. The present invention uses low-temperature molten salt as a chlorinating agent to destroy the structure of the solid vanadium source through infiltration to achieve the release of vanadium. The reaction temperature is 160-200°C, which is more environmentally friendly than using chlorine as a chlorinating agent, has high process controllability and good safety.

[0057] 3. The "molten salt chlorination and distillation reaction device for enriching and purifying vanadium" adopted in the present invention is a multifunctional integrated structure, which integrates a molten salt device, a chlorination device and a condensation device into one. Compared with the existing series reaction device, the number of pipelines and valves used in the present invention is reduced, and the vanadium trichloride gas is not easy to leak, and the safety is high. In addition, compared with the integrated chlorination reaction device in the prior art, the molten salt device and the chlorination device provided can also prevent the molten salt from partially volatilizing due to heat during the preparation process, and prevent the volatilized chloride from adhering to the inner wall of the chlorination device and entering the vanadium trichloride gas, thereby effectively inhibiting the reduction of the purity of the reaction product; agitators A and agitators B are respectively provided in the molten salt device and the chlorination device, and the contact areas between the molten salt and the molten salt and between the solid vanadium source and the molten salt are increased by the agitators A and the agitators B, thereby improving the molten salt preparation efficiency and the chlorination efficiency, and the vanadium extraction rate is more than 85%.

[0058] Therefore, the present invention 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 the method has high purity. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] Figure 1 It is a structural schematic diagram of a molten salt chlorination distillation reaction device for enriching and purifying vanadium adopted in the present 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 DESCRIPTION

[0065] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments, but 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 method for enriching and purifying vanadium by molten salt chlorination distillation adopts 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 A1 and a high-temperature circulating oil bath B3.

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

[0069] Step 1: Preparation of molten chloride salt

[0070] Step 1.1, adding the chlorinating agent into the molten salt device 2 through the feed port A7 of the molten salt device 2 at a ratio of the volume of the chlorinating agent to the volume of the molten salt device 2 of 0.3:1.

[0071] Step 1.2, set the temperature of the high-temperature circulating oil bath A1 to 130°C, and the heated silicone oil enters the interlayer A9 from the oil bath outlet A21 through the second insulation tube A from the oil inlet 16 of the molten salt device, and the silicone oil entering the interlayer A9 enters the high-temperature circulating oil bath A1 from the oil bath outlet 8 through the first insulation tube A from the oil bath oil inlet A20 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 chloride 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 pipeline 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, adding the solid vanadium source into the chlorination device 4 through the feed port B23 of the chlorination device 4 according to the molar ratio of vanadium in the solid vanadium source to the chlorination agent being 1:1.

[0076] Step 2.2, set the temperature of the high-temperature circulating oil bath B3 to 160°C, and the heated silicone oil enters the interlayer B27 from the oil outlet B38 of the oil bath through the second insulation pipe B from the oil inlet 32 ​​of the chlorination device, and the silicone oil entering the interlayer B27 enters the high-temperature circulating oil bath B3 from the oil outlet 26 of the chlorination device through the first insulation pipe B from the oil inlet B37 of the oil bath to circulate and heat the chlorination device 4.

[0077] Step 2.3, when the temperature sensor B33 of the chlorination device 4 reaches the set temperature of the high-temperature circulating oil bath B3, the agitator B28 starts stirring at a speed of 200r / min; the external protective gas is simultaneously input from the air inlet B24 of the chlorination device 4, and the agitator B28 stirs for 1h to obtain vanadium trichloride gas.

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

[0079] Step 3: Condensation collection

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

[0081] Step 3.2, the vanadium trichloride gas entering the condensing device 5 enters the condenser 39 from the collecting tank 44 through the gas outlet C45, and obtains the vanadium trichloride liquid after condensation. The vanadium trichloride liquid flows back into the collecting tank 44 through the gas outlet C45; the tail gas is discharged from the tail gas collecting pipe 40.

[0082] Step 3.3, opening the collecting valve 43 of the condensing device 5 to obtain the vanadium oxychloride liquid.

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

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

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

[0086] The chlorination device 4 is a sandwich tank with stirring, and is provided with at least a molten salt input port 25, a feed port B23 and a gas outlet B35 on the top, and at least a slag discharge pipe 30 on the bottom;

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

[0088] The high temperature circulating oil bath device is used to perform oil bath heating on the interlayers of the molten salt device and the chlorination device respectively.

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

[0090] like Figure 2 As shown, the body A11 is a double-layer cylinder, and an interlayer A9 is provided between the outer wall and the inner wall of the body A11. The interlayer A9 is filled with high-temperature silicone oil, and the high-temperature silicone oil heats the body A11. The port of the body A11 is fixedly connected to the cover plate A18 by bolts, and a sealing ring is provided between the 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 A18, and a temperature sensor through hole A is provided on the other side of the center of the cover A18; the temperature measuring end of the temperature sensor A17 passes through the temperature sensor through hole A at the lower part of the inner cavity of the body A11, and the wiring terminal of the sensor A17 is externally connected to the speed regulator A6. A stirrer through hole A is provided at the center of the cover A18, and the lower end of the stirrer A10 passes through the stirrer through hole A at the lower part of the inner cavity of the body A11, and a stirring paddle A is provided at the lower end of the stirrer A10, and the upper end of the stirrer A10 is connected to the output shaft of the motor A19 through a coupling, and the wiring terminal of the motor A19 is externally connected to the speed regulator A6.

[0092] like Figure 2 As shown, an oil outlet 8 of a molten salt device is provided at the upper part of one side of the circular wall outer surface of the main body A11, and an oil inlet 16 of a molten salt device is provided at the lower part of the other side of the circular wall outer surface of the main body A11; a discharge port is provided at the bottom center of the main body A11, and a discharge pipe 12 and a molten salt output pipe 14 are installed at the discharge port, a first discharge valve 13 is provided at the pipe mouth of the discharge pipe 12, and a second discharge valve 15 is provided at the pipe mouth 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 bath oil inlet A20 of the high-temperature circulating oil bath A1 through the first insulation pipe A, and the oil inlet 16 of the molten salt device is connected to the oil bath oil outlet A21 of the high-temperature circulating oil bath A1 through the second insulation pipe A.

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

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

[0096] like Figure 4 As shown, one side of the center of the cover plate B34 is provided with a molten salt input port 25, an air inlet B24 and a feed port B23 from outside to inside, and the other side of the center of the cover plate B34 is provided with a temperature sensor through hole B and an air outlet B35 from inside to outside; the temperature measuring end of the temperature sensor B33 passes through the temperature sensor through hole B at the lower part of the inner cavity of the body B29, and the connection terminal of the temperature sensor B33 is externally connected to the speed regulator B36. A stirrer through hole B is provided at the center of the cover plate B34, and the lower end of the stirrer B28 passes through the stirrer through hole B at the lower part of the inner cavity of the body B29, and a stirring paddle B is provided at the lower end of the stirrer B28. The upper end of the stirrer B28 is connected to the output shaft of the motor B22 through a coupling, and the connection terminal of the motor B22 is externally connected to the speed regulator B36.

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

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

[0099] The condensing device 5 has a structure as follows Figure 6 As shown: it consists of a collecting tank 44 and a condenser 39.

[0100] like Figure 6 As shown, the collecting tank 44 is a hollow sphere, a collecting pipe 42 is provided at the bottom of the hollow sphere, a collecting valve 43 is provided at the mouth of the collecting pipe 42, an air inlet C41 is provided on the left side of the hollow sphere, and an air outlet C45 is provided on the upper part of the hollow sphere.

[0101] like Figure 6As shown, the condenser 39 is composed of a condenser tube shell 46, a serpentine condenser tube 47 and an exhaust gas collecting tube 40, wherein the serpentine condenser tube 47 and the exhaust gas collecting tube 40 are coaxially installed in the condenser tube shell 46; the lower port of the serpentine condenser tube 47 passes through the lower part of the condenser tube shell 46, and the lower port of the serpentine condenser tube 47 is a liquid inlet, and the upper port of the serpentine condenser tube 47 passes through the upper part of the condenser tube shell 46, and the upper port of the serpentine condenser tube 47 is a liquid outlet; the liquid inlet is externally connected to the liquid outlet pipe of the low-temperature coolant circulator, and the liquid outlet is externally connected to the liquid inlet pipe of the low-temperature coolant circulator.

[0102] like Figure 6 As shown, the gas outlet C45 of the collecting tank 44 is fixedly connected to the lower end of the condenser tube shell 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 with the molten salt input port 25 of the chlorination device 4 through the first pipeline B, and the prepared molten salt flows out from the molten salt output pipe 14 and enters the chlorination device 4 from the molten salt input port 25 through the first pipeline B; the gas outlet B35 of the chlorination device 4 is connected with the gas inlet C41 of the collection tank 44 through the second pipeline B, and the prepared vanadium trichloride gas is output from the gas outlet B35 and enters the condensation device 5 from the gas inlet C41 through the second pipeline B.

[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 prepared by oxidizing and then hydrolyzing vanadium from vanadium shale leaching solution; the vanadium content in the solid vanadium source is 10wt%.

[0108] The condensing agent is ethylene glycol; the condensing temperature of the condensing agent is -10°C.

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

[0110] The dissolving agent is hydrochloric acid.

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

[0112] Example 2

[0113] A method for enriching and purifying vanadium by molten salt chlorination distillation. This embodiment is the same as embodiment 1 except for the following.

[0114] Step 1: Preparation of molten chloride salt

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

[0116] Step 1.2, set the temperature of the high-temperature circulating oil bath A1 to 170°C, and the heated silicone oil enters the interlayer A9 from the oil outlet A21 of the oil bath through the second insulation tube A from the oil inlet 16 of the molten salt device, and the silicone oil entering the interlayer A9 enters the high-temperature circulating oil bath A1 from the oil outlet 8 of the molten salt device through the first insulation tube A from the oil inlet A20 of the oil bath 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 chloride 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 pipeline 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, adding the solid vanadium source into the chlorination device 4 through the feed port B23 of the chlorination device 4 according to the molar ratio of vanadium in the solid vanadium source to the chlorinating agent of 1:2.

[0121] Step 2.2, set the temperature of the high-temperature circulating oil bath B3 to 170°C, and the heated silicone oil enters the interlayer B27 from the oil outlet B38 of the oil bath through the second insulation pipe B from the oil inlet 32 ​​of the chlorination device, and the silicone oil entering the interlayer B27 enters the high-temperature circulating oil bath B3 from the oil outlet 26 of the chlorination device through the first insulation pipe B from the oil inlet B37 of the oil bath to circulate and heat the chlorination device 4.

[0122] Step 2.3, when the temperature sensor B33 of the chlorination device 4 reaches the set temperature of the high-temperature circulating oil bath B3, the agitator B28 starts stirring at a speed of 350r / min; the external protective gas is simultaneously input from the air inlet B24 of the chlorination device 4, and the agitator B28 stirs for 1.5h to obtain vanadium trichloride gas.

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

[0124] Step 3: Condensation collection

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

[0126] Step 3.2, the vanadium trichloride gas entering the condensing device 5 enters the condenser 39 from the collecting tank 44 through the gas outlet C45, and obtains the vanadium trichloride liquid after condensation. The vanadium trichloride liquid flows back into the collecting tank 44 through the gas outlet C45; the tail gas is discharged from the tail gas collecting pipe 40.

[0127] Step 3.3, opening the collecting valve 43 of the condensing device 5 to obtain the vanadium oxychloride liquid.

[0128] The vanadium oxychloride liquid is mixed with a solvent to obtain a vanadium-rich liquid, 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 prepared by oxidizing and then hydrolyzing vanadium from vanadium shale leaching solution; the vanadium content in the solid vanadium source is 13wt%.

[0133] The condensing agent is ethylene glycol; the condensing temperature of the condensing agent 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 trichloride prepared in this embodiment was tested to have a purity of 99.923%; and the vanadium extraction rate was calculated to be 88.1%.

[0137] Example 3

[0138] A method for enriching and purifying vanadium by molten salt chlorination distillation. This embodiment is the same as embodiment 1 except for the following.

[0139] Step 1: Preparation of molten chloride salt

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

[0141] Step 1.2, set the temperature of the high-temperature circulating oil bath A1 to 210°C, and the heated silicone oil enters the interlayer A9 from the oil bath outlet A21 through the second insulation tube A from the oil inlet 16 of the molten salt device, and the silicone oil entering the interlayer A9 enters the high-temperature circulating oil bath A1 from the oil bath outlet 8 through the first insulation tube A from the oil bath oil inlet A20 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 chloride 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 pipeline 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, adding the solid vanadium source into the chlorination device 4 through the feed port B23 of the chlorination device 4 according to the molar ratio of vanadium in the solid vanadium source to the chlorination agent of 1:3.

[0146] Step 2.2, set the temperature of the high-temperature circulating oil bath B3 to 180°C, and the heated silicone oil enters the interlayer B27 from the oil outlet B38 of the oil bath through the second insulation pipe B from the oil inlet 32 ​​of the chlorination device, and the silicone oil entering the interlayer B27 enters the high-temperature circulating oil bath B3 from the oil outlet 26 of the chlorination device through the first insulation pipe B from the oil inlet B37 of the oil bath to circulate and heat the chlorination device 4.

[0147] Step 2.3, when the temperature sensor B33 of the chlorination device 4 reaches the set temperature of the high-temperature circulating oil bath B3, the agitator B28 starts stirring at a speed of 500r / min; the external protective gas is simultaneously input from the air inlet B24 of the chlorination device 4, and the agitator B28 stirs for 2h to obtain vanadium trichloride gas.

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

[0149] Step 3: Condensation collection

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

[0151] Step 3.2, the vanadium trichloride gas entering the condensing device 5 enters the condenser 39 from the collecting tank 44 through the gas outlet C45, and obtains the vanadium trichloride liquid after condensation. The vanadium trichloride liquid flows back into the collecting tank 44 through the gas outlet C45; the tail gas is discharged from the tail gas collecting pipe 40.

[0152] Step 3.3, opening the collecting valve 43 of the condensing device 5 to obtain the vanadium oxychloride liquid.

[0153] The vanadium oxychloride liquid is mixed with a solvent to obtain a vanadium-rich liquid, 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 prepared by oxidizing and then hydrolyzing vanadium from vanadium shale leaching solution; the vanadium content in the solid vanadium source is 15wt%.

[0158] The condensing agent is ethanol; the condensing temperature of the condensing agent is 10°C.

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

[0160] The dissolving agent is sulfuric acid.

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

[0162] Example 4

[0163] A method for enriching and purifying vanadium by molten salt chlorination distillation. This embodiment is the same as embodiment 1 except for the following.

[0164] Step 1: Preparation of molten chloride salt

[0165] Step 1.1, adding the chlorinating agent into the molten salt device 2 through the feed port A7 of the molten salt device 2 at a ratio of the volume of the chlorinating agent to the volume of the molten salt device 2 of 0.8:1.

[0166] Step 1.2, set the temperature of the high-temperature circulating oil bath A1 to 250°C, and the heated silicone oil enters the interlayer A9 from the oil bath outlet A21 through the second insulation tube A from the oil inlet 16 of the molten salt device, and the silicone oil entering the interlayer A9 enters the high-temperature circulating oil bath A1 from the oil bath outlet 8 through the first insulation tube A from the oil bath oil inlet A20 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 chloride 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 pipeline 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, adding the solid vanadium source into the chlorination device 4 through the feed port B23 of the chlorination device 4 according to the molar ratio of vanadium in the solid vanadium source to the chlorination agent of 1:4.

[0171] Step 2.2, set the temperature of the high-temperature circulating oil bath B3 to 200°C, and the heated silicone oil enters the interlayer B27 from the oil bath outlet B38 through the second insulation pipe B from the oil inlet 32 ​​of the chlorination device, and the silicone oil entering the interlayer B27 enters the high-temperature circulating oil bath B3 from the oil bath outlet 26 of the chlorination device through the first insulation pipe B from the oil bath inlet B37 to circulate and heat the chlorination device 4.

[0172] Step 2.3, when the temperature sensor B33 of the chlorination device 4 reaches the set temperature of the high-temperature circulating oil bath B3, the agitator B28 starts stirring at a speed of 600r / min; the external protective gas is simultaneously input from the air inlet B24 of the chlorination device 4, and the agitator B28 stirs for 3h to obtain vanadium trichloride gas.

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

[0174] Step 3: Condensation collection

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

[0176] Step 3.2, the vanadium trichloride gas entering the condensing device 5 enters the condenser 39 from the collecting tank 44 through the gas outlet C45, and obtains the vanadium trichloride liquid after condensation. The vanadium trichloride liquid flows back into the collecting tank 44 through the gas outlet C45; the tail gas is discharged from the tail gas collecting pipe 40.

[0177] Step 3.3, opening the collecting valve 43 of the condensing device 5 to obtain the vanadium oxychloride liquid.

[0178] The vanadium oxychloride liquid is mixed with a solvent to obtain a vanadium-rich liquid, 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 prepared by oxidizing and then hydrolyzing vanadium from vanadium shale leaching solution; the vanadium content in the solid vanadium source is 18wt%.

[0183] The condensing agent is water; the condensing temperature of the condensing agent 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 trichloride prepared in this embodiment was tested to have a purity of 99.931%; and the vanadium extraction rate was calculated to be 86.8%.

[0187] Compared with the prior art, this specific implementation has the following positive effects:

[0188] 1. This specific implementation method adopts a molten salt chlorination distillation reaction device for enriching and purifying vanadium to enrich and purify vanadium. Compared with the existing solvent extraction method and ion exchange method, the vanadium shale leachate is subjected to oxidation-hydrolysis vanadium precipitation and then to a single-stage chlorination distillation process to obtain a vanadium trichloride liquid with a purity of ≥99.9%. There is no need for a multi-stage continuous process, the process flow is short, and the vanadium impurity separation effect is good; therefore, the obtained vanadium trichloride has a high purity, and the purity of the further obtained vanadium pentoxide product is ≥99.9%.

[0189] 2. This specific implementation method uses low-temperature molten salt as a chlorinating agent to destroy the structure of the solid vanadium source through infiltration to achieve the release of vanadium. The reaction temperature is 160-200°C, which is more environmentally friendly than using chlorine as a chlorinating agent, has high process controllability and good safety.

[0190] 3. The "molten salt chlorination and distillation reaction device for enriching and purifying vanadium" adopted in this specific embodiment is a multifunctional integrated structure, which integrates the molten salt device 2, the chlorination device 4 and the condensation device 5 into one. Compared with the existing series reaction device, the number of pipelines and valves used in this specific embodiment is reduced, the vanadium trichloride gas is not easy to leak, and the safety is high; compared with the integrated chlorination reaction device in the prior art, the molten salt device 2 and the chlorination device 4 provided can also prevent the molten salt from partially volatilizing due to heat during the preparation process, and prevent the volatilized chloride from adhering to the inner wall of the chlorination device 4 and entering the vanadium trichloride gas, thereby effectively inhibiting the reduction of the purity of the reaction product; agitators A10 and B28 are respectively provided in the molten salt device 2 and the chlorination device 4, and the contact areas between the molten salt and the molten salt and between the solid vanadium source and the molten salt are increased by the agitators A10 and B28, thereby improving the molten salt preparation efficiency and the chlorination efficiency, and the vanadium extraction rate is more than 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 adopts a device called "molten salt chlorination distillation reaction device for enriching and purifying vanadium", which comprises 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: Step 1, preparation of chloride molten salt, adding a chlorinating agent into a molten salt device (2), heating the molten salt device (2) in an oil bath, setting the heating temperature to 130-250° C., reacting under stirring to obtain chloride molten salt; Step 2, chlorination reaction, adding molten chloride and solid vanadium source into the chlorination device (4), heating the chlorination device (4) in an oil bath, setting the heating temperature to 160-200° C., reacting under stirring conditions to obtain vanadium trichloride gas; Step 3, condensation and collection, introducing the obtained vanadium oxychloride gas into a condensation device (5), condensing the vanadium oxychloride gas by using the condensation device (5), and collecting the vanadium oxychloride liquid.

2. The method for enriching and purifying vanadium by molten salt chlorination distillation according to claim 1, characterized in that: Step 1 is as follows: Step 1.1, adding the chlorinating agent into the molten salt device (2) through the feed port A (7) of the molten salt device (2) at a ratio of the volume of the chlorinating agent to the volume of the molten salt device (2) of 0.3 to 0.8:1; Step 1.2, setting the temperature of the high-temperature circulating oil bath A (1) to 130-250° C., the heated silicone oil enters the interlayer A (9) from the oil bath outlet A (21) through the second insulation pipe A from the oil inlet (16) of the molten salt device, and the silicone oil entering the interlayer A (9) enters the high-temperature circulating oil bath A (1) from the oil bath outlet A (8) through the first insulation pipe A from the oil bath inlet A (20), so as 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 to 500 r / min for 30 to 60 min 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 flows from the molten salt output pipe (14) of the molten salt device (2) through the first pipeline B and the molten salt input port (25) into the chlorination device (4).

3. The method for enriching and purifying vanadium by molten salt chlorination distillation according to claim 1, characterized in that: The details of step 2 are as follows: Step 2.1, adding the solid vanadium source into the chlorination device (4) through the feed port B (23) of the chlorination device (4) according to the molar ratio of vanadium in the solid vanadium source to the chlorination agent of 1:1 to 4; Step 2.2, setting the temperature of the high-temperature circulating oil bath B (3) to 160-200° C., the heated silicone oil enters the interlayer B (27) from the oil bath outlet B (38) through the second insulation pipe B from the oil inlet (32) of the chlorination device, and the silicone oil entering the interlayer B (27) enters the high-temperature circulating oil bath B (3) from the oil bath outlet B (26) of the chlorination device through the first insulation pipe B from the oil bath inlet B (37), so as to circulate and heat the chlorination device (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 to 600 r / min; the external protective gas is simultaneously input from the air inlet B (24) of the chlorination device (4), and the stirrer B (28) stirs for 1 to 3 hours to obtain vanadium trichloride gas; Step 2.4, the vanadium oxychloride gas enters the condensing device (5) from the gas outlet B (35) of the chlorination device (4) through the second pipeline B and the gas inlet C (41).

4. The method for enriching and purifying vanadium by molten salt chlorination distillation according to claim 1, characterized in that: The details of step 3 are as follows: Step 3.1, inputting the condensing agent into the condenser (39) from the liquid inlet at the lower end of the serpentine condensing tube (47) of the condensing device (5), and then flowing out from the liquid outlet at the upper end of the serpentine condensing tube (47), wherein the flow rate of the condensing agent is 1 to 4 m / s; Step 3.2, the vanadium oxychloride gas entering the condensing device (5) enters the condenser (39) from the collecting tank (44) through the gas outlet C (45), and is condensed to obtain a vanadium oxychloride liquid, and the vanadium oxychloride liquid flows back into the collecting tank (44) through the gas outlet C (45); Step 3.3, opening the collecting valve (43) of the condensing device (5) to obtain the vanadium oxychloride liquid.

5. 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), the chlorination device (4), the condensation device (5), the high-temperature circulating oil bath A (1) and the high-temperature circulating oil bath B (3) are as follows: The molten salt device (2) is composed of a speed regulator A (6), an agitator A (10), a body A (11), a temperature sensor A (17), a cover plate A (18) and a motor A (19); The body A (11) is in a double-layer cylindrical shape, and an interlayer A (9) is provided between the outer wall and the inner wall of the body A (11), and the interlayer A (9) is filled with high-temperature silicone oil, and the high-temperature silicone oil heats the body A (11); the port of the body A (11) is fixedly connected to the cover plate A (18) by bolts, and a sealing ring is provided between the 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); a temperature measuring end of the temperature sensor A (17) passes through the temperature sensor through hole A at the lower part of the inner cavity of the body A (11), and a connection terminal of the sensor A (17) is externally connected to a speed regulator A (6); a stirrer through hole A is provided at the center of the cover plate A (18), a lower end of the stirrer A (10) passes through the stirrer through hole A at the lower part of the inner cavity of the body A (11), a stirring paddle A is provided at the lower end of the stirrer A (10), an upper end of the stirrer A (10) is connected to an output shaft of a motor A (19) through a coupling, and a connection terminal of the motor A (19) is externally connected to a speed regulator A (6); An oil outlet (8) of a molten salt device is provided at the upper portion of one side of the circular wall outer surface of the body A (11), and an oil inlet (16) of a molten salt device is provided at the lower portion of the other side of the circular wall outer surface of the body A (11); a discharge port is provided at the center of the bottom of the body A (11), and a discharge pipe (12) and a molten salt output pipe (14) are installed at the discharge port; a first discharge valve (13) is provided at the pipe mouth of the discharge pipe (12), and a second discharge valve (15) is provided at the pipe mouth of the molten salt output pipe (14); The oil outlet (8) of the molten salt device is connected to the oil bath oil inlet (20) of the high-temperature circulating oil bath A (1) through the first insulation pipe A, and the oil inlet (16) of the molten salt device is connected to the oil bath oil outlet (21) of the high-temperature circulating oil bath A (1) through the second insulation pipe A; The chlorination device (4) is composed 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 body B (29) is in a double-layer cylindrical shape. An interlayer B (27) is provided between the outer wall and the inner wall of the body B (29). High-temperature silicone oil is contained in the interlayer B (27). The high-temperature silicone oil heats the body B (11). The port of the body B (29) is fixedly connected to the cover plate B (34) by bolts. A sealing ring is provided between the body B (29) and the cover plate B (34). A molten salt input port (25), an air inlet B (24) and a feeding port B (23) are sequentially arranged on one side of the center of the cover plate B (34) from outside to inside, and a temperature sensor through hole B and an air outlet B (35) are sequentially arranged on the other side of the center of the cover plate B (34) from inside to outside; a temperature measuring end of the temperature sensor B (33) passes through the temperature sensor through hole B at the lower part of the inner cavity of the body B (29), and a connection terminal of the temperature sensor B (33) is externally connected to a speed regulator B (36); a stirrer through hole B is arranged at the center of the cover plate B (34), a lower end of the stirrer B (28) passes through the stirrer through hole B at the lower part of the inner cavity of the body B (29), a stirring paddle B is arranged at the lower end of the stirrer B (28), an upper end of the stirrer B (28) is connected to an output shaft of a motor B (22) through a coupling, and a connection terminal of the motor B (22) is externally connected to a speed regulator B (36); An oil outlet (26) for the chlorination device is provided at the upper portion of one side of the circular wall outer surface of the body B (29), and an oil inlet (32) for the chlorination device is provided at the lower portion of the other side of the circular wall outer surface of the body B (29); a slag discharge pipe (30) is provided at the center of the bottom of the body B (29), and a slag discharge valve (31) is provided at the pipe mouth of the slag discharge pipe (30); The oil outlet (26) of the chlorination device is communicated with the oil bath oil inlet (37) of the high-temperature circulating oil bath B (3) through the first insulation pipe B, and the oil inlet (32) of the chlorination device is communicated with the oil bath oil outlet (38) of the high-temperature circulating oil bath B (3) through the second insulation pipe B; The condensing device (5) is composed of a collecting tank (44) and a condenser (39); The collecting tank (44) is a hollow sphere, a collecting pipe (42) is provided at the bottom of the hollow sphere, a collecting valve (43) is provided at the pipe mouth of the collecting pipe (42), an air inlet C (41) is provided on the left side of the hollow sphere, and an air outlet C (45) is provided on the upper part of the hollow sphere; The condenser (39) is composed of a condenser tube shell (46), a serpentine condenser tube (47) and an exhaust gas collecting tube (40), wherein the serpentine condenser tube (47) and the exhaust gas collecting tube (40) are coaxially installed in the condenser tube shell (46); the lower port of the serpentine condenser tube (47) passes through the lower part of the condenser tube shell (46), and the lower port of the serpentine condenser tube (47) is a liquid inlet; the upper port of the serpentine condenser tube (47) passes through the upper part of the condenser tube shell (46), and the upper port of the serpentine condenser tube (47) is a liquid outlet; the liquid inlet is externally connected to the liquid outlet pipe of the low-temperature coolant circulator, and the liquid outlet is externally connected to the liquid inlet pipe of the low-temperature coolant circulator; The gas outlet C (45) of the collecting 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 a first pipe B, and the prepared molten salt is output from the molten salt output pipe (14) and enters the chlorination device (4) from the molten salt input port (25) through the first pipe B; the gas outlet B (35) of the chlorination device (4) is connected to the gas inlet C (41) of the collection tank (44) through a second pipe B, and the prepared vanadium oxychloride gas is output from the gas outlet B (35) and enters the condensation device (5) from the gas inlet C (41) through the second pipe B.

6. 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.

7. 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.

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

9. The method for enriching and purifying vanadium by molten salt chlorination distillation according to claim 1, characterized in that The condensing agent is one of water, ethanol and ethylene glycol; the condensing temperature of the condensing agent is -10 to 20°C.

10. The method for enriching and purifying vanadium by molten salt chlorination distillation according to claim 1, characterized in that The protective gas is nitrogen or argon; the flow rate of the protective gas is 5 to 20 L / min.

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