Method for purifying tungsten from vanadium-containing tungstate solution

Abstract

The invention belongs to the technical field of hydrometallurgy, and particularly relates to a method for purifying tungsten from a vanadium-containing tungstate solution, which comprises the following steps of: adjusting the pH value of the vanadium-containing tungstate solution to 9-13, adding a vulcanizing agent for vulcanizing, and converting vanadium in the vanadium-containing tungstate solution into one or more of VO2S <->, VOS2 <-> and VS3 <-> by incomplete thiolation. And the vanadium-containing tungstate solution subjected to vulcanization treatment is subjected to powdery tungstic acid preparation, acid pickling and ammonia dissolution to obtain an ammonium tungstate solution with the vanadium concentration smaller than or equal to 0.005 g / L. The method is thorough in tungsten extraction, simple to operate, low in cost and easy to realize industrial production.

Description

Technical Field

[0001] The present invention belongs to the technical field of hydrometallurgy, and particularly relates to a method for purifying tungsten from a vanadium-containing tungstate solution. Background Art

[0002] Vanadium and tungsten both belong to rare high-melting-point metals, and their chemical properties are similar to those of tungsten. It is difficult to completely separate vanadium from tungsten during the extraction process of tungsten. With the increasing depletion of tungsten ore resources, more and more secondary tungsten resources containing impurities such as vanadium are being used. The main waste tungsten-containing metal materials are: tungsten carbide, carbide bonding debris, tool steel, abrasives, waste catalysts, cutting materials, filaments, etc. An important feature of waste tungsten-containing metal materials is that the tungsten content is very high. Waste tungsten metal products often contain other valuable metal components, such as Mo, V, Co, Ni, Cu, Ta, Nb, Ti, Re, etc. Recycling these valuable metals is of great significance for resource recycling and environmental protection. However, there is little research on the technical process for recovering tungsten and vanadium from waste tungsten-containing metal materials.

[0003] Currently, patents for the recovery of tungsten and vanadium mainly focus on ion exchange and solvent extraction. Patent CN104294045B records that after adjusting the pH value of the vanadium-containing tungstate solution to 8 - 11, a sulfiding agent is added for sulfiding treatment to convert the vanadium form in the vanadium-containing tungstate solution into VS4 3- ; the sulfided vanadium-containing tungstate solution is subjected to anion adsorption and exchange through an ion exchange column filled with weakly basic anion exchange resin to obtain a tungstate solution with a vanadium concentration less than 0.01 g / L.

[0004] Patent CN107922994B records that a reducing agent suitable for reducing pentavalent vanadium to one or more lower vanadium oxidation states is used to treat tungsten-containing substances in an aqueous solution, so that tungsten can be more easily separated from vanadium, and tungsten and vanadium are separated by solvent extraction.

[0005] Patent CN104862485A records that waste catalysts are pretreated to obtain titanium slag and a vanadium-tungsten solution; the vanadium-tungsten solution is subjected to extraction separation. The obtained vanadium-rich raffinate is reprocessed to obtain vanadium pentoxide; the tungsten-rich organic phase separated is back-extracted, then subjected to two-stage extraction for tungsten extraction, and then back-extracted to obtain an ammonium tungstate solution, which can be reprocessed to produce ammonium paratungstate.

[0006] The pre-treated waste SCR denitration catalyst is crushed, mixed with a sodium source and roasted. After the roasted material is crushed, water leaching is carried out at a liquid-solid ratio of 5-8 mL:1 g. The slurry is separated into a filtrate and a filter residue, the filter residue is washed, and the washing liquid and the filtrate are combined. Monoethanolamine, an active component source, and a co-catalytic component source are added to the combined liquid so that the active component metal element in the solution is 3-5 wt%, and the co-catalytic component metal element is 1-8 wt%, and then stirred. The raw material solution is kneaded with a titanium source, and the kneaded mud is pre-extruded, extruded into a shape, dried and roasted to obtain a new denitration catalyst.

[0007] The above method has an extremely cumbersome process, a long flow, and consumes a large amount of reagents. Therefore, it is very necessary to design a new process for deep vanadium removal in vanadium-containing tungstate solutions with a short process, wide adaptability, and good effects. Summary of the Invention

[0008] Aiming at a series of defects existing in the existing vanadium removal technology for tungstate, such as incomplete vanadium removal, limitations of vanadium removal by the type and tungsten content of tungstate, complex operation, high cost, etc., the purpose of the present invention is to provide a method for purifying tungsten from vanadium-containing tungstate solutions. The method is to adjust the pH value of the vanadium-containing tungstate solution to 9-13, then add a sulfiding agent for sulfiding treatment, and incompletely thio-convert the vanadium in the vanadium-containing tungstate solution into one or more of VO2S - , VOS2 - , VS3 - . The sulfided vanadium-containing tungstate solution is used to prepare powdery tungstic acid, pickled, and ammonia-dissolved to obtain an ammonium tungstate solution with a vanadium concentration ≤ 0.005 g / L, where the vanadium is measured as V2O5.

[0009] The method for purifying tungsten from vanadium-containing tungstate solutions includes the following steps: S1. Obtain a vanadium-containing tungstate solution; S2. Add a sulfiding agent to the vanadium-containing tungstate solution to incompletely thio-convert it to obtain a thio-treated solution; S3. Mix the thio-treated solution with dilute hydrochloric acid, stir and heat; S4. Filter to obtain tungstic acid and wash it, and dissolve the tungstic acid with ammonia water to obtain an ammonium tungstate solution.

[0010] As a preferred scheme of the method for purifying tungsten from vanadium-containing tungstate solutions of the present invention, wherein: in the step S2, the molar ratio of sulfur in the sulfiding agent to vanadium in the vanadium-containing tungstate solution is (4-6):1, and the vanadium in the vanadium-containing tungstate solution is incompletely thio-converted into one or more of VO2S - , VOS2 - , VS3 - .

[0011] As a preferred embodiment of the method for purifying tungsten from a vanadium-containing tungstate solution according to the present invention, wherein: step S3 specifically comprises: S31. The dilute hydrochloric acid and the post-thiolation solution are added successively in a molar ratio of hydrogen ions in the dilute hydrochloric acid to tungsten in the post-thiolation solution of (4 - 5):1. S32. Step S31 is repeatedly executed until the tungstate ions in the post-thiolation solution completely react.

[0012] As a preferred embodiment of the method for purifying tungsten from a vanadium-containing tungstate solution according to the present invention, wherein: in step S1, the vanadium-containing tungstate solution includes: sodium vanadotungstate solution, and / or potassium vanadotungstate solution. The tungsten content of the vanadium-containing tungstate solution is 150 - 300 g / L in terms of WO3, and the vanadium content of the vanadium-containing tungstate solution is 0.1 - 2.0 g / L in terms of V2O5.

[0013] As a preferred embodiment of the method for purifying tungsten from a vanadium-containing tungstate solution according to the present invention, wherein: step S1 further includes: adjusting the pH value of the vanadium-containing tungstate solution to 9 - 13, and the substances for adjusting the pH include HCl, H2WO4, WO3 or NaOH.

[0014] As a preferred embodiment of the method for purifying tungsten from a vanadium-containing tungstate solution according to the present invention, wherein: in step S2, the sulfurizing agent includes: ammonium sulfide, sodium sulfide or sodium hydrosulfide.

[0015] As a preferred embodiment of the method for purifying tungsten from a vanadium-containing tungstate solution according to the present invention, wherein: in step S2, the sulfurizing agent is added to the vanadium-containing tungstate solution, the temperature for incomplete thiolation is 20 - 30 °C, and the reaction time is 0.5 - 12 h.

[0016] As a preferred embodiment of the method for purifying tungsten from a vanadium-containing tungstate solution according to the present invention, wherein: in step S3, the stirring speed is 200 - 500 r / min, and the heating temperature is 90 - 100 °C.

[0017] As a preferred embodiment of the method for purifying tungsten from a vanadium-containing tungstate solution according to the present invention, wherein: in step S4, the tungstic acid is powdered tungstic acid.

[0018] As a preferred embodiment of the method for purifying tungsten from a vanadium-containing tungstate solution according to the present invention, wherein: in step S4, the vanadium content of the ammonium tungstate solution is ≤ 0.005 g / L in terms of V2O5.

[0019] As a preferred embodiment of the method for purifying tungsten from a vanadium-containing tungstate solution according to the present invention, wherein: in step S4, filtration is performed during the preparation of the tungstic acid. More preferably, the filtration is hot filtration.

[0020] The beneficial effects of the present invention are as follows: The present invention adopts a scheme of incomplete thionation of vanadium. By means of hydrometallurgy, a sulfiding agent is added to the vanadium-containing tungstate solution to treat the vanadium therein, so that the vanadium is incompletely thionated into VO2S - , VOS2 - , VS3 - or one or more of them. By utilizing the different solubilities of VO2S - , VOS2 - , VS3 - under acidic conditions, it will not affect the solution system during the subsequent preparation of tungstic acid. Vanadium remains in the solution and does not need to be removed. After the prepared powdered tungstic acid is pickled and ammonia-dissolved, the ammonium tungstate solution obtained has a low vanadium content and the purification of tungsten is relatively thorough. Specific embodiments

[0021] The technical solutions in the embodiments will be clearly and completely described below. Apparently, the described embodiments are only a part of the embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0022] The present invention provides a method for purifying tungsten from a vanadium-containing tungstate solution. Through the incomplete thionation of vanadium, by means of hydrometallurgy, a sulfiding agent is added to the vanadium-containing tungstate solution to treat the vanadium therein, so that the vanadium is incompletely thionated into VO2S - , VOS2 - , VS3 - or one or more of them. By utilizing the different solubilities of VO2S - , VOS2 - , VS3 - under acidic conditions, it will not affect the solution system during the subsequent preparation of tungstic acid, and the purpose of relatively thorough purification of tungsten is achieved.

[0023] According to one aspect of the present invention, the present invention provides the following technical solutions: A method for purifying tungsten from a vanadium-containing tungstate solution, comprising the following steps: S1. Obtain a vanadium-containing tungstate solution; S2. Add a sulfiding agent to the vanadium-containing tungstate solution to make it incompletely thionated to obtain a post-thionation solution; S3. Mix the post-thionation solution with dilute hydrochloric acid, stir and heat; S4. Filter to obtain tungstic acid and wash it, and dissolve it with ammonia water to obtain an ammonium tungstate solution.

[0024] Preferably, in the step S1, the vanadium-containing tungstate solution includes: sodium vanadotungstate solution, and / or, potassium vanadotungstate solution. The tungsten content of the vanadium-containing tungstate solution is 150-300 g / L in terms of WO3, and the vanadium content of the vanadium-containing tungstate solution is 0.1-2.0 g / L in terms of V2O5. Specifically, the tungsten content can be, for example but not limited to, any one of 150 g / L, 175 g / L, 200 g / L, 225 g / L, 250 g / L, 300 g / L or the range between the two, and the vanadium content can be, for example but not limited to, any one of 0.1 g / L, 0.3 g / L, 0.5 g / L, 0.7 g / L, 1.2 g / L, 1.5 g / L, 2.0 g / L or the range between the two.

[0025] Preferably, the step S1 further includes: adjusting the pH value of the vanadium-containing tungstate solution to 9-13. The substances for adjusting the pH include: HCl, H2WO4, WO3 or NaOH. Specifically, the pH value can be, for example but not limited to, any one of 9, 9.5, 10, 10.5, 11, 11.5, 12, 13 or the range between the two.

[0026] Preferably, in the step S2, the sulfurizing agent includes: ammonium sulfide, sodium sulfide or sodium hydrosulfide. The molar ratio of sulfur in the sulfurizing agent to vanadium in the vanadium-containing tungstate solution is (4-6):1. The vanadium in the vanadium-containing tungstate solution is not completely sulfurized and converted into VO2S - , VOS2 - , VS3 - or one or several of them. The reaction temperature is 20-30 °C, and the reaction time is 0.5-12 h. Specifically, the molar ratio can be, for example but not limited to, any one of 4.0:1, 4.2:1, 4.5:1, 5.0:1, 6.0:1 or the range between the two, the reaction temperature can be, for example but not limited to, any one of 20 °C, 23 °C, 25 °C, 28 °C, 30 °C or the range between the two, and the reaction time can be, for example but not limited to, any one of 0.5 h, 1 h, 2 h, 5 h, 8 h, 10 h, 12 h or the range between the two.

[0027] Preferably, in the step S3, the stirring speed is 200-500 r / min, and the heating temperature is 90-100 °C. Specifically, the stirring speed can be, for example but not limited to, any one of 200 r / min, 250 r / min, 300 r / min, 350 r / min, 400 r / min, 450 r / min, 500 r / min or the range between the two, and the heating temperature can be, for example but not limited to, any one of 90 °C, 92 °C, 95 °C, 98 °C, 100 °C or the range between the two.

[0028] Preferably, step S3 is specifically as follows: S31. The dilute hydrochloric acid and the post-thiourea solution are added in sequence according to a molar ratio of hydrogen ions in the dilute hydrochloric acid to tungsten in the post-thiourea solution of (4-5):1; S32. Step S31 is repeatedly executed until the tungstate ions in the post-thiourea solution completely react. Specifically, the molar ratio of hydrogen ions in the dilute hydrochloric acid to tungsten in the post-thiourea solution can be, for example but not limited to, any one of 4.0:1, 4.2:1, 4.4:1, 4.6:1, 4.8:1, 5.0:1 or the range between the two.

[0029] Preferably, in step S4, the tungstic acid is powdered tungstic acid.

[0030] Preferably, in step S4, filtration is performed during the preparation of the tungstic acid. More preferably, the filtration is hot filtration.

[0031] Preferably, in step S4, the vanadium content in the ammonium tungstate solution is ≤0.005 g / L in terms of V2O5. Specifically, the vanadium content in terms of V2O5 can be, for example but not limited to, any one of 0.001 g / L, 0.002 g / L, 0.003 g / L, 0.004 g / L, 0.005 g / L or the range between the two.

[0032] The technical solution of the present invention will be further described below in conjunction with specific embodiments.

[0033] Example 1 A method for purifying tungsten from a vanadium-containing tungstate solution includes the following steps: Take 400 mL of a sodium vanadotungstate solution, where the tungsten content is 250.34 g / L in terms of WO3 and the vanadium content is 0.24 g / L in terms of V2O5. Stir and add dilute hydrochloric acid to adjust the pH to 10; Add a sodium sulfide solution to the sodium vanadotungstate solution and stir. The molar ratio of sulfur in the added sodium sulfide to vanadium in the sodium vanadotungstate solution is 6:1. The reaction temperature is 25 °C and the sulfidation time is 1 h. After the reaction is completed, a post-thiourea solution is obtained; Take 40 mL of hydrochloric acid with a concentration of 31 wt% and 200 mL of water, add them together into a reaction kettle, stir at a speed of 200 r / min, and heat to 95 °C. Dropwise add 80 mL of post-thiolation solution into the reaction kettle, and the dropping time is 12 min. Keep stirring at a speed of 200 r / min, maintain the temperature of the reaction kettle at 95 °C, then add 40 mL of hydrochloric acid with a concentration of 31 wt% into the reaction kettle in sequence, dropwise add 80 mL of post-thiolation solution, and repeat the above steps of adding hydrochloric acid and post-thiolation solution in sequence 4 times. Filter while it is hot to obtain powdery tungstic acid, wash it twice with hydrochloric acid with a concentration of 3 wt%, dissolve the washed powdery tungstic acid with ammonia water to obtain ammonium tungstate solution. The tungsten content in the ammonium tungstate solution is 240.71 g / L in terms of WO3, and the vanadium content in the ammonium tungstate solution is 0.002 g / L in terms of V2O5.

[0034] Example 2 A method for purifying tungsten from a vanadium-containing tungstate solution, comprising the following steps: Take 400 mL of sodium vanadotungstate solution, where the tungsten content is 153.34 g / L in terms of WO3 and the vanadium content is 0.47 g / L in terms of V2O5. Stir and add H2WO4 to adjust the pH to 13, and measure the WO3 content to be 180.32 g / L; Add sodium sulfide solution to the sodium vanadotungstate solution and stir. The molar ratio of sulfur in the added sodium sulfide to vanadium in the sodium vanadotungstate solution is 5:1. The reaction temperature is 25 °C and the sulfidation time is 3 h. After the reaction is completed, a post-thiolation solution is obtained; Take 29 mL of hydrochloric acid with a concentration of 31 wt% and 150 mL of water, add them together into a reaction kettle, stir at a speed of 200 r / min, and heat to 95 °C. Dropwise add 80 mL of post-thiolation solution into the reaction kettle, and the dropping time is 12 min. Keep stirring at a speed of 200 r / min, maintain the temperature of the reaction kettle at 95 °C, then add 29 mL of hydrochloric acid with a concentration of 31 wt% into the reaction kettle in sequence, dropwise add 80 mL of post-thiolation solution, and repeat the above steps of adding hydrochloric acid and post-thiolation solution in sequence 4 times. Filter while it is hot to obtain powdery tungstic acid, wash it twice with hydrochloric acid with a concentration of 3 wt%, dissolve the washed powdery tungstic acid with ammonia water to obtain ammonium tungstate solution. The tungsten content in the ammonium tungstate solution is 250.43 g / L in terms of WO3, and the vanadium content in the ammonium tungstate solution is 0.005 g / L in terms of V2O5.

[0035] Example 3 A method for purifying tungsten from a vanadium-containing tungstate solution, comprising the following steps: Take 400 mL of sodium vanadotungstate solution, where the tungsten content is 170.60 g / L in terms of WO3 and the vanadium content is 0.72 g / L in terms of V2O5. Stir and add WO3 to adjust the pH to 9, and measure the WO3 content to be 270.51 g / L; Add sodium sulfide solution to the sodium tungstate solution containing vanadium and stir. The molar ratio of sulfur in the added sodium sulfide to vanadium in the sodium tungstate solution containing vanadium is 5:1. The reaction temperature is 25 °C and the sulfidation time is 6 h. After the reaction is completed, a post-thiolation solution is obtained. Take 43 mL of hydrochloric acid with a concentration of 31 wt% and 200 mL of water, add them to the reaction kettle together, stir at a speed of 200 r / min, and heat to 95 °C. Add 80 mL of the post-thiolation solution dropwise to the reaction kettle, and the dropping time is 12 min. Keep stirring at a speed of 200 r / min and maintain the temperature of the reaction kettle at 95 °C. Then add 43 mL of hydrochloric acid with a concentration of 31 wt% to the reaction kettle in sequence, and add 80 mL of the post-thiolation solution dropwise. Repeat the above steps of adding hydrochloric acid and the post-thiolation solution in sequence 4 times. Filter while it is hot to obtain powdery tungstic acid, wash it twice with hydrochloric acid with a concentration of 3 wt%, and dissolve the washed powdery tungstic acid with ammonia water to obtain an ammonium tungstate solution. The tungsten content in the ammonium tungstate solution is 246.81 g / L in terms of WO3, and the vanadium content in the ammonium tungstate solution is 0.004 g / L in terms of V2O5.

[0036] Example 4 A method for purifying tungsten from a vanadium-containing tungstate solution, comprising the following steps: Take 400 mL of sodium tungstate solution containing vanadium, where the tungsten content is 163.41 g / L in terms of WO3 and the vanadium content is 0.204 g / L in terms of V2O5. Stir and add dilute hydrochloric acid to adjust the pH to 9. Add sodium sulfide solution to the sodium tungstate solution containing vanadium and stir. The molar ratio of sulfur in the added sodium sulfide to vanadium in the sodium tungstate solution containing vanadium is 4:1. The reaction temperature is 25 °C and the sulfidation time is 0.5 h. After the reaction is completed, a post-thiolation solution is obtained. Take 26 mL of hydrochloric acid with a concentration of 31 wt% and 200 mL of water, add them to the reaction kettle together, stir at a speed of 200 r / min, and heat to 95 °C. Add 80 mL of the post-thiolation solution dropwise to the reaction kettle, and the dropping time is 12 min. Keep stirring at a speed of 200 r / min and maintain the temperature of the reaction kettle at 95 °C. Then add 26 mL of hydrochloric acid with a concentration of 31 wt% to the reaction kettle in sequence, and add 80 mL of the post-thiolation solution dropwise. Repeat the above steps of adding hydrochloric acid and the post-thiolation solution in sequence 4 times. Filter while it is hot to obtain powdery tungstic acid, wash it twice with hydrochloric acid with a concentration of 3 wt%, and dissolve the washed powdery tungstic acid with ammonia water to obtain an ammonium tungstate solution. The tungsten content in the ammonium tungstate solution is 250.36 g / L in terms of WO3, and the vanadium content in the ammonium tungstate solution is 0.002 g / L in terms of V2O5.

[0037] Example 5 A method for purifying tungsten from a vanadium-containing tungstate solution, comprising the following steps: Take 400 mL of a vanadium-containing sodium tungstate solution, where the tungsten content is 220.33 g / L in terms of WO3 and the vanadium content is 0.421 g / L in terms of V2O5. Stir and add dilute hydrochloric acid to adjust the pH to 9; Add a sodium sulfide solution to the vanadium-containing sodium tungstate solution and stir. The molar ratio of sulfur in the added sodium sulfide to vanadium in the vanadium-containing sodium tungstate solution is 5:1. The reaction temperature is 25 °C and the sulfidation time is 0.5 h. After the reaction is completed, a post-thiolation solution is obtained; Take 35 mL of hydrochloric acid with a concentration of 31 wt% and 200 mL of water, add them together to a reaction kettle, stir at a speed of 200 r / min, and heat to 95 °C. Add 80 mL of the post-thiolation solution dropwise to the reaction kettle over 12 min. Keep stirring at a speed of 200 r / min and maintain the temperature of the reaction kettle at 95 °C. Then, add 35 mL of hydrochloric acid with a concentration of 31 wt% to the reaction kettle in sequence, and add 80 mL of the post-thiolation solution dropwise. Repeat the above steps of adding hydrochloric acid and the post-thiolation solution 4 times. Filter while it is hot to obtain powdery tungstic acid, wash it twice with hydrochloric acid with a concentration of 3 wt%. The washed powdery tungstic acid is dissolved in ammonia water to obtain an ammonium tungstate solution. The tungsten content in the ammonium tungstate solution is 240.71 g / L in terms of WO3, and the vanadium content in the ammonium tungstate solution is 0.003 g / L in terms of V2O5.

[0038] Example 6 A method for purifying tungsten from a vanadium-containing tungstate solution, comprising the following steps: Take 400 mL of a vanadium-containing sodium tungstate solution, where the tungsten content is 250.68 g / L in terms of WO3 and the vanadium content is 1.344 g / L in terms of V2O5. Stir and add dilute hydrochloric acid to adjust the pH to 9; Add a sodium sulfide solution to the vanadium-containing sodium tungstate solution and stir. The molar ratio of sulfur in the added sodium sulfide to vanadium in the vanadium-containing sodium tungstate solution is 6:1. The reaction temperature is 25 °C and the sulfidation time is 0.5 h. After the reaction is completed, a post-thiolation solution is obtained; Take 40 mL of hydrochloric acid with a concentration of 31 wt% and 200 mL of water, add them together to a reaction kettle, stir at a speed of 200 r / min, and heat to 95 °C. Add 80 mL of the post-thiolation solution dropwise to the reaction kettle over 12 min. Keep stirring at a speed of 200 r / min and maintain the temperature of the reaction kettle at 95 °C. Then, add 40 mL of hydrochloric acid with a concentration of 31 wt% to the reaction kettle in sequence, and add 80 mL of the post-thiolation solution dropwise. Repeat the above steps of adding hydrochloric acid and the post-thiolation solution 4 times. Filter while it is hot to obtain powdery tungstic acid, wash it twice with hydrochloric acid with a concentration of 3 wt%. The washed powdery tungstic acid is dissolved in ammonia water to obtain an ammonium tungstate solution. The tungsten content in the ammonium tungstate solution is 251.21 g / L in terms of WO3, and the vanadium content in the ammonium tungstate solution is 0.005 g / L in terms of V2O5.

[0039] Example 7 A method for purifying tungsten from a vanadium tungstate solution, comprising the following steps: Take 400 mL of a sodium vanadium tungstate solution, where the tungsten content is 280.29 g / L in terms of WO3 and the vanadium content is 0.833 g / L in terms of V2O5. Stir and add dilute hydrochloric acid to adjust the pH to 11; Add a sodium sulfide solution to the sodium vanadium tungstate solution and stir. The molar ratio of sulfur in the added sodium sulfide to vanadium in the sodium vanadium tungstate solution is 4:1. The reaction temperature is 25 °C and the sulfidation time is 0.5 h. After the reaction is completed, a post-sulfidation solution is obtained; Take 45 mL of hydrochloric acid with a concentration of 31 wt% and 200 mL of water, add them to a reaction kettle together, stir at a speed of 200 r / min, and heat to 95 °C. Dropwise add 80 mL of the post-sulfidation solution to the reaction kettle, and the dropping time is 12 min; Keep stirring at a speed of 200 r / min and maintain the temperature of the reaction kettle at 95 °C. Then add 45 mL of hydrochloric acid with a concentration of 31 wt% to the reaction kettle in sequence, and dropwise add 80 mL of the post-sulfidation solution. Repeat the above steps of adding hydrochloric acid and the post-sulfidation solution 4 times; Filter while it is hot to obtain powdery tungstic acid, wash it 2 times with hydrochloric acid with a concentration of 3 wt%. The washed powdery tungstic acid is dissolved in ammonia water to obtain an ammonium tungstate solution. The tungsten content in the ammonium tungstate solution is 253.45 g / L in terms of WO3, and the vanadium content in the ammonium tungstate solution is 0.003 g / L in terms of V2O5.

[0040] Example 8 A method for purifying tungsten from a vanadium tungstate solution, comprising the following steps: Take 400 mL of a sodium vanadium tungstate solution, where the tungsten content is 244.67 g / L in terms of WO3 and the vanadium content is 1.837 g / L in terms of V2O5. Stir and add sodium hydroxide to adjust the pH to 13; Add a sodium sulfide solution to the sodium vanadium tungstate solution and stir. The molar ratio of sulfur in the added sodium sulfide to vanadium in the sodium vanadium tungstate solution is 4:1. The reaction temperature is 25 °C and the sulfidation time is 0.5 h. After the reaction is completed, a post-sulfidation solution is obtained; Take 39 mL of hydrochloric acid with a concentration of 31 wt% and 200 mL of water, add them together into the reaction kettle, stir at a speed of 200 r / min, and heat to 95 °C. Dropwise add 80 mL of post-thiourea solution into the reaction kettle, and the dropping time is 12 min. Keep stirring at a speed of 200 r / min, maintain the temperature of the reaction kettle at 95 °C, then add 39 mL of hydrochloric acid with a concentration of 31 wt% into the reaction kettle in sequence, dropwise add 80 mL of post-thiourea solution, and repeat the above steps of adding hydrochloric acid and post-thiourea solution in sequence 4 times. Filter while it is hot to obtain powdery tungstic acid, wash it 2 times with hydrochloric acid with a concentration of 3 wt%, dissolve the washed powdery tungstic acid with ammonia water to obtain ammonium tungstate solution, the tungsten content in the ammonium tungstate solution is 246.38 g / L in terms of WO3, and the vanadium content in the ammonium tungstate solution is 0.005 g / L in terms of V2O5.

[0041] Example 9 A method for purifying tungsten from a vanadium-containing tungstate solution, comprising the following steps: Take 400 mL of sodium vanadotungstate solution, wherein the tungsten content is 250.68 g / L in terms of WO3 and the vanadium content is 1.344 g / L in terms of V2O5, stir and add dilute hydrochloric acid to adjust the pH to 9; Add sodium sulfide solution to the sodium vanadotungstate solution and stir. The molar ratio of sulfur in the added sodium sulfide to vanadium in the sodium vanadotungstate solution is 4:1, the reaction temperature is 25 °C, and the sulfidation time is 6 h. After the reaction is completed, a post-thiourea solution is obtained; Take 40 mL of hydrochloric acid with a concentration of 31 wt% and 200 mL of water, add them together into the reaction kettle, stir at a speed of 200 r / min, and heat to 95 °C. Dropwise add 80 mL of post-thiourea solution into the reaction kettle, and the dropping time is 12 min. Keep stirring at a speed of 200 r / min, maintain the temperature of the reaction kettle at 95 °C, then add 40 mL of hydrochloric acid with a concentration of 31 wt% into the reaction kettle in sequence, dropwise add 80 mL of post-thiourea solution, and repeat the above steps of adding hydrochloric acid and post-thiourea solution in sequence 4 times. Filter while it is hot to obtain powdery tungstic acid, wash it 2 times with hydrochloric acid with a concentration of 3 wt%, dissolve the washed powdery tungstic acid with ammonia water to obtain ammonium tungstate solution, the tungsten content in the ammonium tungstate solution is 247.35 g / L in terms of WO3, and the vanadium content in the ammonium tungstate solution is 0.003 g / L in terms of V2O5.

[0042] Example 10 A method for purifying tungsten from a vanadium-containing tungstate solution, comprising the following steps: Take 400 mL of sodium vanadotungstate solution, wherein the tungsten content is 250.68 g / L in terms of WO3 and the vanadium content is 1.344 g / L in terms of V2O5, stir and add dilute hydrochloric acid to adjust the pH to 9; Add sodium sulfide solution to the sodium tungstate solution containing vanadium and stir. The molar ratio of sulfur in the added sodium sulfide to vanadium in the sodium tungstate solution containing vanadium is 4:1. The reaction temperature is 25 °C and the sulfidation time is 12 h. After the reaction is completed, a post-thiolation solution is obtained. Take 40 mL of hydrochloric acid with a concentration of 31 wt% and 200 mL of water, add them to the reaction kettle together, stir at a speed of 200 r / min, and heat to 95 °C. Add 80 mL of the post-thiolation solution dropwise to the reaction kettle, and the dropping time is 12 min. Keep stirring at a speed of 200 r / min and maintain the temperature of the reaction kettle at 95 °C. Then add 40 mL of hydrochloric acid with a concentration of 31 wt% to the reaction kettle in turn, and add 80 mL of the post-thiolation solution dropwise. Repeat the above steps of adding hydrochloric acid and the post-thiolation solution 4 times. Filter while it is hot to obtain powdery tungstic acid, wash it twice with hydrochloric acid with a concentration of 3 wt%. The washed powdery tungstic acid is dissolved in ammonia water to obtain an ammonium tungstate solution. The tungsten content in the ammonium tungstate solution is 248.64 g / L in terms of WO3, and the vanadium content in the ammonium tungstate solution is 0.002 g / L in terms of V2O5.

[0043] Example 11 A method for purifying tungsten from a vanadium-containing tungstate solution, comprising the following steps: Take 400 mL of a potassium vanadotungstate solution, where the tungsten content is 280.29 g / L in terms of WO3 and the vanadium content is 0.833 g / L in terms of V2O5. Stir and add dilute hydrochloric acid to adjust the pH to 11. Add sodium sulfide solution to the potassium vanadotungstate solution and stir. The molar ratio of sulfur in the added sodium sulfide to vanadium in the potassium vanadotungstate solution is 4:1. The reaction temperature is 25 °C and the sulfidation time is 0.5 h. After the reaction is completed, a post-thiolation solution is obtained. Take 39.5 mL of hydrochloric acid with a concentration of 31 wt% and 200 mL of water, add them to the reaction kettle together, stir at a speed of 200 r / min, and heat to 95 °C. Add 80 mL of the post-thiolation solution dropwise to the reaction kettle, and the dropping time is 12 min. Keep stirring at a speed of 200 r / min and maintain the temperature of the reaction kettle at 95 °C. Then add 39.5 mL of hydrochloric acid with a concentration of 31 wt% to the reaction kettle in turn, and add 80 mL of the post-thiolation solution dropwise. Repeat the above steps of adding hydrochloric acid and the post-thiolation solution 4 times. Filter while it is hot to obtain powdery tungstic acid, wash it twice with hydrochloric acid with a concentration of 3 wt%. The washed powdery tungstic acid is dissolved in ammonia water to obtain an ammonium tungstate solution. The tungsten content in the ammonium tungstate solution is 244.30 g / L in terms of WO3, and the vanadium content in the ammonium tungstate solution is 0.003 g / L in terms of V2O5.

[0044] Comparative Example 1 A method for purifying tungsten from a vanadium-containing tungstate solution, comprising the following steps: Take 400 mL of a vanadium-containing sodium tungstate solution, where the tungsten content is 250.34 g / L in terms of WO3 and the vanadium content is 0.24 g / L in terms of V2O5. Stir and add hydrochloric acid to adjust the pH to 10.

[0045] Take 200 mL of hydrochloric acid with a concentration of 31 wt% and 200 mL of water, add them to a reaction kettle and mix evenly. Then, dropwise add the vanadium-containing sodium tungstate solution into the reaction kettle at a set dropping rate of 6.67 mL / min to obtain colloidal tungstic acid. Wash it twice with hydrochloric acid with a concentration of 3 wt%. The washed colloidal tungstic acid is dissolved in ammonia water to obtain an ammonium tungstate solution. The tungsten content in the ammonium tungstate solution is 210.40 g / L in terms of WO3, and the vanadium content in the ammonium tungstate solution is 0.124 g / L in terms of V2O5.

[0046] Comparative Example 2 A method for purifying tungsten from a vanadium-containing tungstate solution, comprising the following steps: Take 400 mL of a vanadium-containing sodium tungstate solution, where the tungsten content is 250.34 g / L in terms of WO3 and the vanadium content is 0.24 g / L in terms of V2O5. Stir and add hydrochloric acid to adjust the pH to 10; Take 40 mL of hydrochloric acid with a concentration of 31 wt% and 200 mL of water, put them together into a reaction kettle, stir at a speed of 200 r / min, and heat to 95 °C. Dropwise add 80 mL of the vanadium-containing sodium tungstate solution to the reaction kettle, and the dropping time is 12 minutes. Then, sequentially add 40 mL of hydrochloric acid with a concentration of 31 wt% to the reaction kettle and dropwise add 80 mL of the vanadium-containing sodium tungstate solution. Repeat the above steps of sequentially adding hydrochloric acid and the vanadium-containing sodium tungstate solution 4 times. Filter while it is hot to obtain powdery tungstic acid, wash it twice with hydrochloric acid with a concentration of 3 wt%. The washed powdery tungstic acid is dissolved in ammonia water to obtain an ammonium tungstate solution. The tungsten content is 230.56 g / L in terms of WO3, and the vanadium content is 0.026 g / L in terms of V2O5.

[0047] Comparative Example 3 A method for purifying tungsten from a vanadium-containing tungstate solution, comprising the following steps: Take 400 mL of a vanadium-containing sodium tungstate solution, where the tungsten content is 234.10 g / L in terms of WO3 and the vanadium content is 0.630 g / L in terms of V2O5. Stir and add dilute hydrochloric acid to adjust the pH to 7; Add a sodium sulfide solution to the vanadium-containing sodium tungstate solution and stir. The molar ratio of sulfur in the added sodium sulfide to vanadium in the vanadium-containing sodium tungstate solution is 4:1. The reaction temperature is 25 °C, and the sulfidation time is 0.5 h. After the reaction is completed, a post-sulfurized solution is obtained; Take 37 mL of hydrochloric acid with a concentration of 31 wt% and 200 mL of water, add them together into a reaction kettle, stir at a speed of 200 r / min, and heat to 95 °C. Dropwise add 80 mL of post-thiourea solution into the reaction kettle, and the dropping time is 12 min. Keep stirring at a speed of 200 r / min, maintain the temperature of the reaction kettle at 95 °C, then add 37 mL of hydrochloric acid with a concentration of 31 wt% into the reaction kettle in sequence, dropwise add 80 mL of post-thiourea solution, and repeat the above steps of adding hydrochloric acid and post-thiourea solution in sequence 4 times. Filter while it is hot to obtain powdery tungstic acid, wash it twice with hydrochloric acid with a concentration of 3 wt%, dissolve the washed powdery tungstic acid with ammonia water to obtain ammonium tungstate solution, the tungsten content in the ammonium tungstate solution is 244.63 g / L in terms of WO3, and the vanadium content in the ammonium tungstate solution is 0.010 g / L in terms of V2O5.

[0048] Comparative Example 4 A method for purifying tungsten from a vanadium-containing tungstate solution, comprising the following steps: Take 400 mL of sodium vanadotungstate solution, where the tungsten content is 241.65 g / L in terms of WO3 and the vanadium content is 0.630 g / L in terms of V2O5, stir and add sodium hydroxide to adjust the pH to 14; Add sodium sulfide solution to the sodium vanadotungstate solution and stir. The molar ratio of sulfur in the added sodium sulfide to vanadium in the sodium vanadotungstate solution is 4:1, the reaction temperature is 25 °C, the sulfidation time is 0.5 h, and a post-thiourea solution is obtained after the reaction is completed; Take 38.5 mL of hydrochloric acid with a concentration of 31 wt% and 200 mL of water, add them together into a reaction kettle, stir at a speed of 200 r / min, and heat to 95 °C. Dropwise add 80 mL of post-thiourea solution into the reaction kettle, and the dropping time is 12 min. Keep stirring at a speed of 200 r / min, maintain the temperature of the reaction kettle at 95 °C, then add 38.5 mL of hydrochloric acid with a concentration of 31 wt% into the reaction kettle in sequence, dropwise add 80 mL of post-thiourea solution, and repeat the above steps of adding hydrochloric acid and post-thiourea solution in sequence 4 times. Filter while it is hot to obtain powdery tungstic acid, wash it twice with hydrochloric acid with a concentration of 3 wt%, dissolve the washed powdery tungstic acid with ammonia water to obtain ammonium tungstate solution, the tungsten content in the ammonium tungstate solution is 255.36 g / L in terms of WO3, and the vanadium content in the ammonium tungstate solution is 0.031 g / L in terms of V2O5.

[0049] Comparative Example 5 A method for purifying tungsten from a vanadium-containing tungstate solution, comprising the following steps: Take 400 mL of sodium vanadotungstate solution, where the tungsten content is 250.68 g / L in terms of WO3 and the vanadium content is 1.344 g / L in terms of V2O5, stir and add dilute hydrochloric acid to adjust the pH to 9; Add sodium sulfide solution to the sodium tungstate solution containing vanadium and stir. The molar ratio of sulfur in the added sodium sulfide to vanadium in the sodium tungstate solution containing vanadium is 2:1. The reaction temperature is 25 °C, and the sulfidation time is 0.5 h. After the reaction is completed, a post-thiolation solution is obtained. Take 40 mL of hydrochloric acid with a concentration of 31 wt% and 200 mL of water, add them to the reaction kettle together, stir at a speed of 200 r / min, and heat to 95 °C. Add 80 mL of the post-thiolation solution dropwise to the reaction kettle, and the dropping time is 12 min. Keep stirring at a speed of 200 r / min and maintain the temperature of the reaction kettle at 95 °C. Then add 40 mL of hydrochloric acid with a concentration of 31 wt% to the reaction kettle in sequence, and add 80 mL of the post-thiolation solution dropwise. Repeat the above steps of adding hydrochloric acid and the post-thiolation solution in sequence 4 times. Filter while it is hot to obtain powdery tungstic acid, wash it twice with hydrochloric acid with a concentration of 3 wt%, and dissolve the washed powdery tungstic acid with ammonia water to obtain an ammonium tungstate solution. The tungsten content in the ammonium tungstate solution is 245.06 g / L in terms of WO3, and the vanadium content in the ammonium tungstate solution is 0.094 g / L in terms of V2O5.

[0050] Comparative Example 6 A method for purifying tungsten from a vanadium-containing tungstate solution, comprising the following steps: Take 400 mL of sodium tungstate solution containing vanadium, where the tungsten content is 250.68 g / L in terms of WO3 and the vanadium content is 1.344 g / L in terms of V2O5, stir and add dilute hydrochloric acid to adjust the pH to 9. Add sodium sulfide solution to the sodium tungstate solution containing vanadium and stir. The molar ratio of sulfur in the added sodium sulfide to vanadium in the sodium tungstate solution containing vanadium is 9:1. The reaction temperature is 25 °C, and the sulfidation time is 0.5 h. After the reaction is completed, a post-thiolation solution is obtained. Take 40 mL of hydrochloric acid with a concentration of 31 wt% and 200 mL of water, add them to the reaction kettle together, stir at a speed of 200 r / min, and heat to 95 °C. Add 80 mL of the post-thiolation solution dropwise to the reaction kettle, and the dropping time is 12 min. Keep stirring at a speed of 200 r / min and maintain the temperature of the reaction kettle at 95 °C. Then add 40 mL of hydrochloric acid with a concentration of 31 wt% to the reaction kettle in sequence, and add 80 mL of the post-thiolation solution dropwise. Repeat the above steps of adding hydrochloric acid and the post-thiolation solution in sequence 4 times. Filter while it is hot to obtain powdery tungstic acid, wash it twice with hydrochloric acid with a concentration of 3 wt%, and dissolve the washed powdery tungstic acid with ammonia water to obtain an ammonium tungstate solution. The tungsten content in the ammonium tungstate solution is 246.91 g / L in terms of WO3, and the vanadium content in the ammonium tungstate solution is 0.053 g / L in terms of V2O5.

[0051] Example 1 is different from Comparative Example 1 in that Example 1 adopted the operations of sulfidation and batch addition, while Comparative Example 1 did not. Colloidal tungstic acid was obtained. The colloidal tungstic acid has strong adsorption and is difficult to filter. High-purity ammonium tungstate solution cannot be obtained by ammonia dissolution with ammonia water.

[0052] Example 1 is different from Comparative Example 2 in that Example 1 adopted the operation of sulfidation, while Comparative Example 2 did not. The vanadium content in the finally obtained ammonium tungstate solution is greater than 0.005 g / L. It can be seen that the removal effect of vanadium without sulfidation operation is not good.

[0053] In Example 4, Example 5, Example 6, Comparative Example 5 and Comparative Example 6, in Example 4, Example 5 and Example 6, the sulfiding agent was added at a ratio of the molar ratio of sulfur in the sulfiding agent to vanadium in the vanadium-containing tungstate solution of 4:1, 5:1, and 6:1 respectively, and ammonium tungstate solution with vanadium concentration less than 0.005 g / L was obtained. In Comparative Example 5 and Comparative Example 6, the sulfiding agent was added at a ratio of the molar ratio of sulfur in the sulfiding agent to vanadium in the vanadium-containing tungstate solution of 2:1 and 9:1 respectively, and ammonium tungstate solution with vanadium concentration greater than 0.005 g / L was obtained. It is shown that ammonium tungstate solution with vanadium concentration less than 0.005 g / L can be obtained only when the sulfiding agent is added at a ratio of the molar ratio of sulfur in the sulfiding agent to vanadium in the vanadium-containing tungstate solution of (4-6):1, and the removal of vanadium is relatively complete.

[0054] In Example 6, Example 7, Example 8, Comparative Example 3 and Comparative Example 4, in Example 6, Example 7 and Example 8, the operations were carried out under the conditions of pH 9, 11 and 13 respectively, and ammonium tungstate solution with vanadium concentration less than 0.005 g / L was obtained. In Comparative Example 3 and Comparative Example 4, the operations were carried out under the conditions of pH 7 and 14 respectively, and ammonium tungstate solution with vanadium concentration greater than 0.005 g / L was obtained. It is shown that ammonium tungstate solution with vanadium concentration less than 0.005 g / L can be obtained only when the solution is in the range of pH 9-13, and the removal of vanadium is relatively complete.

[0055] The present invention adopts the scheme of incomplete thioation of vanadium. The sulfiding agent is added to the vanadium-containing tungstate solution by hydrometallurgy method to treat the vanadium therein, so that the vanadium is incompletely thioated into VO2S - , VOS2 - , VS3 - or one or more of them. By using the different solubilities of VO2S - , VOS2 - , VS3 - under acidic conditions, it will not affect the solution system during the subsequent preparation of tungstic acid. Vanadium exists in the solution. Without removing vanadium, tungstic acid can be prepared from tungstate. After pickling and ammonia dissolution, the vanadium content in the obtained ammonium tungstate solution is low, and the purification of tungsten is relatively complete.

[0056] The above are only the preferred embodiments of the present invention, and do not limit the patent scope of the present invention accordingly. Any equivalent structural transformation made by using the content of the specification of the present invention under the inventive concept of the present invention, or any direct / indirect application in other related technical fields shall be included in the patent protection scope of the present invention.

Claims

1. A method for purifying tungsten from a vanadium-containing tungstate solution, characterized in that, It includes the following steps: S1. Obtain a vanadium-containing tungstate solution; S2. Add a sulfurizing agent to the vanadium-containing tungstate solution to make it incompletely thiolated to obtain a post-thiolation solution; S3. Mix the post-thiolation solution with dilute hydrochloric acid, stir and heat; S4. Filter to obtain tungstic acid and wash it. The tungstic acid is dissolved in ammonia water to obtain an ammonium tungstate solution.

2. The method for purifying tungsten from a vanadium-containing tungstate solution according to claim 1, characterized in that, In step S2, the molar ratio of sulfur in the sulfiding agent to vanadium in the vanadium-containing tungstate solution is (4-6):1, and the vanadium in the vanadium-containing tungstate solution is incompletely sulfided and converted into VO2S - 、VOS2 - VS3 - One or more of the .

3. The method for purifying tungsten from a vanadium-containing tungstate solution according to claim 1, characterized in that, The specific content of step S3 is as follows: S31. The dilute hydrochloric acid and the post-thiolation solution are added sequentially according to the molar ratio of hydrogen ions in the dilute hydrochloric acid to tungsten in the post-thiolation solution of (4-5):1; S32. Repeat step S31 until the tungstate ions in the post-thiolation solution react completely.

4. The method for purifying tungsten from a vanadium-containing tungstate solution according to claim 1, wherein, In step S1, the vanadium-containing tungstate solution includes: a sodium vanadium tungstate solution, and / or, a potassium vanadium tungstate solution. The tungsten content of the vanadium-containing tungstate solution is 150-300 g / L in terms of WO3, and the vanadium content of the vanadium-containing tungstate solution is 0.1-2.0 g / L in terms of V2O5.

5. The method for purifying tungsten from a vanadium-containing tungstate solution according to claim 1, characterized in that, Step S1 further includes: adjusting the pH value of the vanadium-containing tungstate solution to 9-13. The substances for adjusting the pH include HCl, H2WO4, WO3 or NaOH.

6. The method for purifying tungsten from a vanadium-containing tungstate solution according to claim 1, wherein In step S2, the sulfurizing agent includes: ammonium sulfide, sodium sulfide or sodium hydrosulfide.

7. The method for purifying tungsten from a vanadium-containing tungstate solution according to claim 1, characterized in that, In step S2, the temperature of the incomplete thiolation is 20-30 °C, and the reaction time is 0.5-12 h.

8. The method for purifying tungsten from a vanadium-containing tungstate solution according to claim 1, wherein In step S3, the stirring speed is 200-500 r / min, and the heating temperature is 90-100 °C.

9. The method for purifying tungsten from a vanadium-containing tungstate solution according to claim 1, characterized in that, In step S4, the tungstic acid is powdered tungstic acid.

10. The method for purifying tungsten from a vanadium-containing tungstate solution according to claim 1, characterized in that, In step S4, the vanadium content of the ammonium tungstate solution is ≤0.005 g / L in terms of V2O5.