Method for purifying tungsten from vanadium-containing tungstate solution

Abstract

The present invention belongs to the field of hydrometallurgy technology, and specifically relates to a method for purifying tungsten from a vanadium-containing tungstate solution. The method comprises adjusting the pH value of the vanadium-containing tungstate solution to 9-13, adding a sulfiding agent for sulfidation treatment, and incompletely sulfiding the vanadium in the vanadium-containing tungstate solution to convert it into VO2S. ‑ 、VOS2 ‑ VS3 ‑ One or more of the following. The vanadium-containing tungstate solution after sulfidation is then prepared into powdered tungstic acid, followed by pickling and ammonia dissolution to yield an ammonium tungstate solution containing vanadium ≤ 0.005 g / L. This method is thorough in extracting tungsten, simple to operate, low in cost, and readily adaptable to industrial production.

Description

Technical Field

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

[0002] Vanadium, like tungsten, is a rare, high-melting-point metal with similar chemical properties to tungsten, making it difficult to completely separate from tungsten during the extraction process. As tungsten ore resources continue to dwindle, the use of secondary tungsten resources containing impurities such as vanadium is increasing. Waste tungsten-containing metal materials primarily include tungsten-containing cemented carbide, carburizing bonding debris, tool steel, abrasives, spent catalysts, cutting materials, and filaments. A key characteristic of waste tungsten-containing metal materials is their very high tungsten content. Waste tungsten metal products often contain other valuable metal components, such as Mo, V, Co, Ni, Cu, Ta, Nb, Ti, and Re. The recovery of these valuable metals is of great significance for resource recycling and environmental protection. However, little research has been conducted on the technical processes for recovering tungsten and vanadium from waste tungsten-containing metal materials.

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

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

[0005] Patent CN104862485A describes pre-treating the waste catalyst to obtain titanium slag and vanadium-tungsten solution; extracting and separating the vanadium-tungsten solution, and reprocessing the obtained vanadium-rich raffinate to obtain vanadium pentoxide; stripping the separated tungsten-rich organic phase, and then performing a two-stage extraction to extract tungsten, and then stripping to obtain an ammonium tungstate solution, which can be further processed to produce ammonium paratungstate.

[0006] Patent CN116139851B records that the pretreated waste SCR denitration catalyst is crushed, mixed with a sodium source and calcined, and the calcined material is crushed and then soaked in water at a liquid-solid ratio of 5-8 mL:1 g; the slurry is separated into solid and liquid to obtain a filtrate and a filter residue, the filter residue is washed, and the washing liquid and the filtrate are combined; monoethanolamine and an active component source and a co-catalytic component source are added to the combined liquid to make the active component metal element in the solution 3-5wt% and the co-catalytic component metal element 1-8wt%, and stirred; the raw material solution is mixed with a titanium source, and the mixed mud is pre-extruded, extruded, dried and calcined to obtain a new denitration catalyst.

[0007] The above methods are extremely cumbersome, lengthy, and consume a large amount of reagents. Therefore, it is very necessary to design a new process for deep removal of vanadium from vanadium-containing tungstate solutions with a short process, wide adaptability, and good effect. Summary of the Invention

[0008] In order to solve the problems of incomplete vanadium removal, limited by the type of tungstate and the content of tungsten, complicated operation and high cost in the existing tungstate vanadium removal technology, the present invention aims to provide a method for purifying tungsten from a vanadium-containing tungstate solution. The method comprises adjusting the pH value of the vanadium-containing tungstate solution to 9-13, adding a sulfiding agent for sulfidation treatment, and converting the incomplete vanadium in the vanadium-containing tungstate solution into VO2S. - 、VOS2 - VS3 - The vanadium-containing tungstate solution after sulfidation treatment is prepared by preparing powdered tungstic acid, pickling and ammonia dissolution to obtain an ammonium tungstate solution with a vanadium concentration of ≤0.005g / L, wherein the vanadium is measured as V2O5.

[0009] The method for purifying tungsten from a vanadium-containing tungstate solution comprises the following steps:

[0010] S1. Obtaining a vanadium-containing tungstate solution;

[0011] S2, adding a sulfiding agent to the vanadium-containing tungstate solution to incompletely sulfidate it to obtain a sulfided liquid;

[0012] S3, mixing the thiolated liquid with dilute hydrochloric acid, stirring and heating;

[0013] S4. Filter and wash the tungstic acid, and dissolve the tungstic acid with ammonia water to obtain an ammonium tungstate solution.

[0014] As a preferred embodiment of the method for purifying tungsten from a vanadium-containing tungstate solution of the present invention, wherein: 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 .

[0015] As a preferred embodiment of the method for purifying tungsten from a vanadium-containing tungstate solution according to the present invention, step S3 is specifically as follows:

[0016] S31, the dilute hydrochloric acid and the thiolated liquid are added in sequence according to a molar ratio of hydrogen ions in the dilute hydrochloric acid to tungsten in the thiolated liquid of (4-5):1;

[0017] S32, repeating step S31 until the tungstate ions in the post-thiolation solution react completely.

[0018] As a preferred embodiment of the method for purifying tungsten from a vanadium-containing tungstate solution of the present invention, in step S1, the vanadium-containing tungstate solution includes: a vanadium-containing sodium tungstate solution, and / or a vanadium-containing potassium tungstate solution, the tungsten content of the vanadium-containing tungstate solution is measured as WO3 and is 150-300 g / L, and the vanadium content of the vanadium-containing tungstate solution is measured as V2O5 and is 0.1-2.0 g / L.

[0019] As a preferred embodiment of the method for purifying tungsten from a vanadium-containing tungstate solution of the present invention, step S1 further comprises adjusting the pH value of the vanadium-containing tungstate solution to 9-13, and the substance for adjusting the pH comprises HCl, H2WO4, WO3 or NaOH.

[0020] As a preferred embodiment of the method for purifying tungsten from a vanadium-containing tungstate solution according to the present invention, in step S2, the sulfiding agent includes ammonium sulfide, sodium sulfide or sodium hydrosulfide.

[0021] As a preferred embodiment of the method for purifying tungsten from a vanadium-containing tungstate solution of the present invention, in step S2, the sulfiding agent is added to the vanadium-containing tungstate solution, the temperature of the incomplete sulfidation is 20-30° C., and the reaction time is 0.5-12 h.

[0022] As a preferred embodiment of the method for purifying tungsten from a vanadium-containing tungstate solution of the present invention, in step S3, the stirring speed is 200-500 r / min, and the heating temperature is 90-100°C.

[0023] As a preferred embodiment of the method for purifying tungsten from a vanadium-containing tungstate solution of the present invention, in step S4, the tungstic acid is powdered tungstic acid.

[0024] As a preferred embodiment of the method for purifying tungsten from a vanadium-containing tungstate solution of the present invention, in step S4, the vanadium content of the ammonium tungstate solution is measured as V2O5 and is ≤0.005 g / L.

[0025] As a preferred embodiment of the method for purifying tungsten from a vanadium-containing tungstate solution of the present invention, in step S4, filtration is performed during the preparation of the tungstic acid. More preferably, the filtration is performed while hot.

[0026] The beneficial effects of the present invention are as follows:

[0027] The present invention adopts the scheme of incomplete sulfidation of vanadium. A sulfiding agent is added to the vanadium-containing tungstate solution by a hydrometallurgical method to treat the vanadium therein, so that the vanadium is incompletely sulfided into VO2S. - 、VOS2 - VS3 - One or more of them, using VO2S - 、VOS2 - VS3 - The different solubility under acidic conditions will not affect the solution system in the subsequent preparation of tungstic acid. Vanadium exists in the solution and does not need to be removed. After the prepared powdered tungstic acid is acid-washed and ammonia-dissolved, the obtained ammonium tungstate solution has a low vanadium content and the purification of tungsten is more thorough. DETAILED DESCRIPTION

[0028] The following will be a clear and complete description of the technical solutions in the embodiments. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0029] The present invention proposes a method for purifying tungsten from a vanadium-containing tungstate solution. By incomplete sulfidation of vanadium, a sulfiding agent is added to the vanadium-containing tungstate solution in a hydrometallurgical manner to treat the vanadium therein, so that the vanadium is incompletely sulfided into VO2S. - 、VOS2 - VS3 - One or more of them, using VO2S - 、VOS2 - VS3 - Their different solubilities under acidic conditions will not affect the solution system during the subsequent preparation of tungstic acid, thus achieving the goal of more thorough purification of tungsten.

[0030] According to one aspect of the present invention, the present invention provides the following technical solutions:

[0031] The method for purifying tungsten from a vanadium-containing tungstate solution comprises the following steps:

[0032] S1. Obtaining a vanadium-containing tungstate solution;

[0033] S2, adding a sulfiding agent to the vanadium-containing tungstate solution to incompletely sulfidate it to obtain a sulfided liquid;

[0034] S3, mixing the thiolated liquid with dilute hydrochloric acid, stirring and heating;

[0035] S4. Filter and wash the tungstic acid, and dissolve it with ammonia water to obtain ammonium tungstate solution.

[0036] Preferably, in step S1, the vanadium-containing tungstate solution includes: a vanadium-containing sodium tungstate solution and / or a vanadium-containing potassium tungstate solution, the tungsten content of the vanadium-containing tungstate solution being 150-300 g / L as measured by WO3, and the vanadium content of the vanadium-containing tungstate solution being 0.1-2.0 g / L as measured by V2O5. Specifically, the tungsten content may 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, and 300 g / L, or a range therebetween, and the vanadium content may 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, and 2.0 g / L, or a range therebetween.

[0037] Preferably, step S1 further comprises adjusting the pH of the vanadium-containing tungstate solution to 9-13, wherein the pH-adjusting substance comprises HCl, H2WO4, WO3, or NaOH. Specifically, the pH value may be, for example, but not limited to, any one of 9, 9.5, 10, 10.5, 11, 11.5, 12, 13, or a range therebetween.

[0038] Preferably, in step S2, the sulfiding agent includes ammonium sulfide, sodium sulfide or sodium hydrosulfide, and 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 - 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, and 6.0:1, or a range therebetween; the reaction temperature can be, for example, but not limited to, any one of 20° C., 23° C., 25° C., 28° C., and 30° C., or a range therebetween; 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, and 12 h, or a range therebetween.

[0039] Preferably, in step S3, the stirring speed is 200-500 r / min, and the heating temperature is 90-100° C. Specifically, the stirring speed may 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, and 500 r / min, or a range therebetween, and the heating temperature may be, for example, but not limited to, any one of 90° C., 92° C., 95° C., 98° C., and 100° C., or a range therebetween.

[0040] Preferably, the step S3 is specifically as follows:

[0041] S31, the dilute hydrochloric acid and the thiolated liquid are added in sequence according to a molar ratio of hydrogen ions in the dilute hydrochloric acid to tungsten in the thiolated liquid of (4-5):1;

[0042] S32: Repeat step S31 until the tungstate ions in the post-thiolation solution are completely reacted. Specifically, the molar ratio of hydrogen ions in the dilute hydrochloric acid to tungsten in the post-thiolation 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, and 5.0:1, or a range therebetween.

[0043] Preferably, in step S4, the tungstic acid is powdered tungstic acid.

[0044] Preferably, in step S4, filtration is performed during the preparation of the tungstic acid. More preferably, the filtration is performed while hot.

[0045] Preferably, in step S4, the vanadium content of the ammonium tungstate solution is measured as V2O5 and is ≤0.005 g / L. Specifically, the vanadium content, measured as 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 a range therebetween.

[0046] The technical solution of the present invention is further described below with reference to specific embodiments.

[0047] Example 1

[0048] A method for purifying tungsten from a vanadium-containing tungstate solution comprises the following steps:

[0049] Take 400 mL of vanadium-containing sodium tungstate solution, in which the tungsten content is measured as WO3 to be 250.34 g / L and the vanadium content is measured as V2O5 to be 0.24 g / L, stir and add dilute hydrochloric acid to adjust the pH to 10;

[0050] Sodium sulfide solution is added to the vanadium-containing sodium tungstate solution and stirred. 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 1 hour. After the reaction is completed, a sulfide solution is obtained.

[0051] 40 mL of 31 wt% hydrochloric acid and 200 mL of water were added to a reactor, stirred at a speed of 200 r / min, and heated to 95°C. 80 mL of the thiolated solution was added dropwise to the reactor for 12 min. The stirring speed was maintained at 200 r / min, and the temperature of the reactor was maintained at 95°C. 40 mL of 31 wt% hydrochloric acid and 80 mL of the thiolated solution were added dropwise to the reactor. The above steps of adding hydrochloric acid and the thiolated solution were repeated 4 times. Powdered tungstic acid was filtered while hot and washed twice with 3 wt% hydrochloric acid. The washed powdered tungstic acid was dissolved in ammonia water to obtain an ammonium tungstate solution. The tungsten content in the ammonium tungstate solution was measured as WO3 and was 240.71 g / L. The vanadium content in the ammonium tungstate solution was measured as V2O5 and was 0.002 g / L.

[0052] Example 2

[0053] A method for purifying tungsten from a vanadium-containing tungstate solution comprises the following steps:

[0054] Take 400 mL of vanadium-containing sodium tungstate solution, in which the tungsten content is measured as WO3 to be 153.34 g / L and the vanadium content is measured as V2O5 to be 0.47 g / L, stir and add H2WO4 to adjust the pH to 13, and the WO3 content is measured to be 180.32 g / L;

[0055] Sodium sulfide solution is added to the vanadium-containing sodium tungstate solution and stirred. 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 3 hours. After the reaction is completed, a sulfide solution is obtained.

[0056] 29 mL of 31 wt% hydrochloric acid and 150 mL of water were added to a reactor, stirred at a speed of 200 r / min, and heated to 95°C. 80 mL of the thiolated solution was added dropwise to the reactor for 12 min. The stirring speed was maintained at 200 r / min, and the temperature of the reactor was maintained at 95°C. 29 mL of 31 wt% hydrochloric acid and 80 mL of the thiolated solution were added dropwise to the reactor. The above steps of adding hydrochloric acid and the thiolated solution were repeated 4 times. Powdered tungstic acid was filtered while hot and washed twice with 3 wt% hydrochloric acid. The washed powdered tungstic acid was dissolved in ammonia water to obtain an ammonium tungstate solution. The tungsten content in the ammonium tungstate solution was measured as WO3 and was 250.43 g / L. The vanadium content in the ammonium tungstate solution was measured as V2O5 and was 0.005 g / L.

[0057] Example 3

[0058] A method for purifying tungsten from a vanadium-containing tungstate solution comprises the following steps:

[0059] Take 400 mL of vanadium-containing sodium tungstate solution, in which the tungsten content is measured as WO3 to be 170.60 g / L and the vanadium content is measured as V2O5 to be 0.72 g / L, stir and add WO3 to adjust the pH to 9. The measured WO3 content is 270.51 g / L;

[0060] Sodium sulfide solution is added to the vanadium-containing sodium tungstate solution and stirred. 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 6 hours. After the reaction is completed, a sulfide solution is obtained.

[0061] 43 mL of 31 wt% hydrochloric acid and 200 mL of water were added to a reactor, stirred at a speed of 200 r / min, and heated to 95°C. 80 mL of the thiolated solution was added dropwise to the reactor for 12 min. The stirring speed was maintained at 200 r / min, and the temperature of the reactor was maintained at 95°C. 43 mL of 31 wt% hydrochloric acid and 80 mL of the thiolated solution were added dropwise to the reactor. The above steps of adding hydrochloric acid and the thiolated solution were repeated 4 times. Powdered tungstic acid was filtered while hot and washed twice with 3 wt% hydrochloric acid. The washed powdered tungstic acid was dissolved in ammonia water to obtain an ammonium tungstate solution. The tungsten content in the ammonium tungstate solution was measured as WO3 and was 246.81 g / L. The vanadium content in the ammonium tungstate solution was measured as V2O5 and was 0.004 g / L.

[0062] Example 4

[0063] A method for purifying tungsten from a vanadium-containing tungstate solution comprises the following steps:

[0064] Take 400 mL of vanadium-containing sodium tungstate solution, in which the tungsten content is measured as WO3 to be 163.41 g / L and the vanadium content is measured as V2O5 to be 0.204 g / L, stir and add dilute hydrochloric acid to adjust the pH to 9;

[0065] Sodium sulfide solution is added to the vanadium-containing sodium tungstate solution and stirred. 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 0.5h. After the reaction is completed, a sulfided liquid is obtained.

[0066] 26 mL of 31 wt% hydrochloric acid and 200 mL of water were added to a reactor, stirred at a speed of 200 r / min, and heated to 95°C. 80 mL of the thiolated solution was added dropwise to the reactor for 12 min. The stirring speed was maintained at 200 r / min, and the temperature of the reactor was maintained at 95°C. 26 mL of 31 wt% hydrochloric acid and 80 mL of the thiolated solution were added dropwise to the reactor. The above steps of adding hydrochloric acid and the thiolated solution were repeated 4 times. Powdered tungstic acid was filtered while hot and washed twice with 3 wt% hydrochloric acid. The washed powdered tungstic acid was dissolved in ammonia water to obtain an ammonium tungstate solution. The tungsten content in the ammonium tungstate solution was measured as WO3 and was 250.36 g / L. The vanadium content in the ammonium tungstate solution was measured as V2O5 and was 0.002 g / L.

[0067] Example 5

[0068] A method for purifying tungsten from a vanadium-containing tungstate solution comprises the following steps:

[0069] Take 400 mL of vanadium-containing sodium tungstate solution, in which the tungsten content is measured as WO3 to be 220.33 g / L and the vanadium content is measured as V2O5 to be 0.421 g / L, stir and add dilute hydrochloric acid to adjust the pH to 9;

[0070] Sodium sulfide solution is added to the vanadium-containing sodium tungstate solution and stirred. 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 0.5h. After the reaction is completed, a sulfided liquid is obtained.

[0071] 35 mL of 31 wt% hydrochloric acid and 200 mL of water were added to a reactor, stirred at a speed of 200 r / min, and heated to 95°C. 80 mL of the thiolated solution was added dropwise to the reactor for 12 min. The stirring speed was maintained at 200 r / min, and the temperature of the reactor was maintained at 95°C. 35 mL of 31 wt% hydrochloric acid and 80 mL of the thiolated solution were added dropwise to the reactor. The above steps of adding hydrochloric acid and the thiolated solution were repeated 4 times. Powdered tungstic acid was filtered while hot and washed twice with 3 wt% hydrochloric acid. The washed powdered tungstic acid was dissolved in ammonia water to obtain an ammonium tungstate solution. The tungsten content in the ammonium tungstate solution was measured as WO3 and was 240.71 g / L. The vanadium content in the ammonium tungstate solution was measured as V2O5 and was 0.003 g / L.

[0072] Example 6

[0073] A method for purifying tungsten from a vanadium-containing tungstate solution comprises the following steps:

[0074] Take 400 mL of vanadium-containing sodium tungstate solution, in which the tungsten content is measured as WO3 to be 250.68 g / L and the vanadium content is measured as V2O5 to be 1.344 g / L, stir and add dilute hydrochloric acid to adjust the pH to 9;

[0075] Sodium sulfide solution is added to the vanadium-containing sodium tungstate solution and stirred. 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 0.5h. After the reaction is completed, a sulfided liquid is obtained.

[0076] 40 mL of 31 wt% hydrochloric acid and 200 mL of water were added to a reactor, stirred at a speed of 200 r / min, and heated to 95°C. 80 mL of the thiolated solution was added dropwise to the reactor for 12 min. The stirring speed was maintained at 200 r / min, and the temperature of the reactor was maintained at 95°C. 40 mL of 31 wt% hydrochloric acid and 80 mL of the thiolated solution were added dropwise to the reactor. The above steps of adding hydrochloric acid and the thiolated solution were repeated 4 times. Powdered tungstic acid was filtered while hot and washed twice with 3 wt% hydrochloric acid. The washed powdered tungstic acid was dissolved in ammonia water to obtain an ammonium tungstate solution. The tungsten content in the ammonium tungstate solution was measured as WO3 and was 251.21 g / L. The vanadium content in the ammonium tungstate solution was measured as V2O5 and was 0.005 g / L.

[0077] Example 7

[0078] A method for purifying tungsten from a vanadium-containing tungstate solution comprises the following steps:

[0079] Take 400 mL of vanadium-containing sodium tungstate solution, in which the tungsten content is measured as WO3 to be 280.29 g / L and the vanadium content is measured as V2O5 to be 0.833 g / L, stir and add dilute hydrochloric acid to adjust the pH to 11;

[0080] Sodium sulfide solution is added to the vanadium-containing sodium tungstate solution and stirred. 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 0.5h. After the reaction is completed, a sulfided liquid is obtained.

[0081] 45 mL of 31 wt% hydrochloric acid and 200 mL of water were added to a reactor, stirred at a speed of 200 r / min, and heated to 95°C. 80 mL of the thiolated solution was added dropwise to the reactor for 12 min. The stirring speed was maintained at 200 r / min, and the temperature of the reactor was maintained at 95°C. 45 mL of 31 wt% hydrochloric acid and 80 mL of the thiolated solution were added dropwise to the reactor. The above steps of adding hydrochloric acid and the thiolated solution were repeated 4 times. Powdered tungstic acid was filtered while hot and washed twice with 3 wt% hydrochloric acid. The washed powdered tungstic acid was dissolved in ammonia water to obtain an ammonium tungstate solution. The tungsten content in the ammonium tungstate solution was measured as WO3 and was 253.45 g / L. The vanadium content in the ammonium tungstate solution was measured as V2O5 and was 0.003 g / L.

[0082] Example 8

[0083] A method for purifying tungsten from a vanadium-containing tungstate solution comprises the following steps:

[0084] Take 400 mL of vanadium-containing sodium tungstate solution, where the tungsten content is measured as WO3 to be 244.67 g / L and the vanadium content is measured as V2O5 to be 1.837 g / L, stir and add sodium hydroxide to adjust the pH to 13;

[0085] Sodium sulfide solution is added to the vanadium-containing sodium tungstate solution and stirred. 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 0.5h. After the reaction is completed, a sulfided liquid is obtained.

[0086] 39 mL of 31 wt% hydrochloric acid and 200 mL of water were added to a reactor, stirred at a speed of 200 r / min, and heated to 95°C. 80 mL of the thiolated solution was added dropwise to the reactor for 12 min. The stirring speed was maintained at 200 r / min, and the temperature of the reactor was maintained at 95°C. 39 mL of 31 wt% hydrochloric acid and 80 mL of the thiolated solution were added dropwise to the reactor. The above steps of adding hydrochloric acid and the thiolated solution were repeated 4 times. Powdered tungstic acid was filtered while hot and washed twice with 3 wt% hydrochloric acid. The washed powdered tungstic acid was dissolved in ammonia water to obtain an ammonium tungstate solution. The tungsten content in the ammonium tungstate solution was measured as WO3 and was 246.38 g / L. The vanadium content in the ammonium tungstate solution was measured as V2O5 and was 0.005 g / L.

[0087] Example 9

[0088] A method for purifying tungsten from a vanadium-containing tungstate solution comprises the following steps:

[0089] Take 400 mL of vanadium-containing sodium tungstate solution, in which the tungsten content is measured as WO3 to be 250.68 g / L and the vanadium content is measured as V2O5 to be 1.344 g / L, stir and add dilute hydrochloric acid to adjust the pH to 9;

[0090] Sodium sulfide solution is added to the vanadium-containing sodium tungstate solution and stirred. 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 6 hours. After the reaction is completed, a sulfide solution is obtained.

[0091] 40 mL of 31 wt% hydrochloric acid and 200 mL of water were added to a reactor, stirred at a speed of 200 r / min, and heated to 95°C. 80 mL of the thiolated solution was added dropwise to the reactor for 12 min. The stirring speed was maintained at 200 r / min, and the temperature of the reactor was maintained at 95°C. 40 mL of 31 wt% hydrochloric acid and 80 mL of the thiolated solution were added dropwise to the reactor. The above steps of adding hydrochloric acid and the thiolated solution were repeated 4 times. Powdered tungstic acid was filtered while hot and washed twice with 3 wt% hydrochloric acid. The washed powdered tungstic acid was dissolved in ammonia water to obtain an ammonium tungstate solution. The tungsten content in the ammonium tungstate solution was measured as WO3 and was 247.35 g / L. The vanadium content in the ammonium tungstate solution was measured as V2O5 and was 0.003 g / L.

[0092] Example 10

[0093] A method for purifying tungsten from a vanadium-containing tungstate solution comprises the following steps:

[0094] Take 400 mL of vanadium-containing sodium tungstate solution, in which the tungsten content is measured as WO3 to be 250.68 g / L and the vanadium content is measured as V2O5 to be 1.344 g / L, stir and add dilute hydrochloric acid to adjust the pH to 9;

[0095] Sodium sulfide solution is added to the vanadium-containing sodium tungstate solution and stirred. 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 12 hours. After the reaction is completed, a sulfide solution is obtained.

[0096] 40 mL of 31 wt% hydrochloric acid and 200 mL of water were added to a reactor, stirred at a speed of 200 r / min, and heated to 95°C. 80 mL of the thiolated solution was added dropwise to the reactor for 12 min. The stirring speed was maintained at 200 r / min, and the temperature of the reactor was maintained at 95°C. 40 mL of 31 wt% hydrochloric acid and 80 mL of the thiolated solution were added dropwise to the reactor. The above steps of adding hydrochloric acid and the thiolated solution were repeated 4 times. Powdered tungstic acid was filtered while hot and washed twice with 3 wt% hydrochloric acid. The washed powdered tungstic acid was dissolved in ammonia water to obtain an ammonium tungstate solution. The tungsten content in the ammonium tungstate solution was measured as WO3 and was 248.64 g / L. The vanadium content in the ammonium tungstate solution was measured as V2O5 and was 0.002 g / L.

[0097] Example 11

[0098] A method for purifying tungsten from a vanadium-containing tungstate solution comprises the following steps:

[0099] Take 400 mL of vanadium-containing potassium tungstate solution, in which the tungsten content is measured as WO3 to be 280.29 g / L and the vanadium content is measured as V2O5 to be 0.833 g / L, stir and add dilute hydrochloric acid to adjust the pH to 11;

[0100] Sodium sulfide solution is added to the vanadium-containing potassium tungstate solution and stirred. The molar ratio of sulfur in the added sodium sulfide to vanadium in the vanadium-containing potassium tungstate solution is 4:1. The reaction temperature is 25°C and the sulfidation time is 0.5h. After the reaction is completed, a sulfide solution is obtained.

[0101] 39.5 mL of 31 wt% hydrochloric acid and 200 mL of water were added to a reactor, stirred at a speed of 200 r / min, and heated to 95°C. 80 mL of the thiolated solution was added dropwise to the reactor for 12 min. The stirring speed was maintained at 200 r / min, and the temperature of the reactor was maintained at 95°C. 39.5 mL of 31 wt% hydrochloric acid and 80 mL of the thiolated solution were added dropwise to the reactor. The above steps of adding hydrochloric acid and the thiolated solution were repeated 4 times. Powdered tungstic acid was filtered while hot and washed twice with 3 wt% hydrochloric acid. The washed powdered tungstic acid was dissolved in ammonia water to obtain an ammonium tungstate solution. The tungsten content in the ammonium tungstate solution was measured as WO3 and was 244.30 g / L. The vanadium content in the ammonium tungstate solution was measured as V2O5 and was 0.003 g / L.

[0102] Comparative Example 1

[0103] A method for purifying tungsten from a vanadium-containing tungstate solution comprises the following steps:

[0104] Take 400 mL of vanadium-containing sodium tungstate solution, in which the tungsten content is measured as WO3 to be 250.34 g / L and the vanadium content is measured as V2O5 to be 0.24 g / L, stir and add hydrochloric acid to adjust the pH to 10.

[0105] Take 200mL of 31wt% hydrochloric acid and 200mL of water, add them to a reactor and mix them evenly, then add vanadium-containing sodium tungstate solution dropwise to the reactor at a dropping speed of 6.67mL / min to obtain colloidal tungstic acid, which is washed twice with 3wt% hydrochloric acid. The washed colloidal tungstic acid is dissolved with ammonia water to obtain an ammonium tungstate solution. The tungsten content in the ammonium tungstate solution is measured as WO3 and is 210.40g / L. The vanadium content in the ammonium tungstate solution is measured as V2O5 and is 0.124g / L.

[0106] Comparative Example 2

[0107] A method for purifying tungsten from a vanadium-containing tungstate solution comprises the following steps:

[0108] Take 400 mL of vanadium-containing sodium tungstate solution, where the tungsten content is measured as WO3 to be 250.34 g / L and the vanadium content is measured as V2O5 to be 0.24 g / L, stir and add hydrochloric acid to adjust the pH to 10;

[0109] 40 mL of 31 wt% hydrochloric acid and 200 mL of water were placed in a reactor, stirred at 200 r / min, and heated to 95°C. 80 mL of vanadium-containing sodium tungstate solution was added dropwise to the reactor over a period of 12 minutes. 40 mL of 31 wt% hydrochloric acid and 80 mL of vanadium-containing sodium tungstate solution were added dropwise to the reactor in sequence, and the above steps of sequentially adding hydrochloric acid and vanadium-containing sodium tungstate solution were repeated four times. Powdered tungstic acid was filtered while hot and washed twice with 3 wt% hydrochloric acid. The washed powdered tungstic acid was dissolved in ammonia to obtain an ammonium tungstate solution, wherein the tungsten content was measured as WO3 at 230.56 g / L and the vanadium content was measured as V2O5 at 0.026 g / L.

[0110] Comparative Example 3

[0111] A method for purifying tungsten from a vanadium-containing tungstate solution comprises the following steps:

[0112] Take 400 mL of vanadium-containing sodium tungstate solution, where the tungsten content is measured as WO3 to be 234.10 g / L and the vanadium content is measured as V2O5 to be 0.630 g / L, stir and add dilute hydrochloric acid to adjust the pH to 7;

[0113] Sodium sulfide solution is added to the vanadium-containing sodium tungstate solution and stirred. 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 0.5h. After the reaction is completed, a sulfided liquid is obtained.

[0114] 37 mL of 31 wt% hydrochloric acid and 200 mL of water were added to a reactor, stirred at a speed of 200 r / min, and heated to 95°C. 80 mL of the thiolated solution was added dropwise to the reactor for 12 min. The stirring speed was maintained at 200 r / min, and the temperature of the reactor was maintained at 95°C. 37 mL of 31 wt% hydrochloric acid and 80 mL of the thiolated solution were added dropwise to the reactor. The above steps of adding hydrochloric acid and the thiolated solution were repeated 4 times. Powdered tungstic acid was filtered while hot and washed twice with 3 wt% hydrochloric acid. The washed powdered tungstic acid was dissolved in ammonia water to obtain an ammonium tungstate solution. The tungsten content in the ammonium tungstate solution was measured as WO3 and was 244.63 g / L. The vanadium content in the ammonium tungstate solution was measured as V2O5 and was 0.010 g / L.

[0115] Comparative Example 4

[0116] A method for purifying tungsten from a vanadium-containing tungstate solution comprises the following steps:

[0117] Take 400 mL of vanadium-containing sodium tungstate solution, where the tungsten content is measured as WO3 to be 241.65 g / L and the vanadium content is measured as V2O5 to be 0.630 g / L, stir and add sodium hydroxide to adjust the pH to 14;

[0118] Sodium sulfide solution is added to the vanadium-containing sodium tungstate solution and stirred. 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 0.5h. After the reaction is completed, a sulfided liquid is obtained.

[0119] 38.5 mL of 31 wt% hydrochloric acid and 200 mL of water were added to a reactor, stirred at a speed of 200 r / min, and heated to 95°C. 80 mL of the thiolated solution was added dropwise to the reactor for 12 min. The stirring speed was maintained at 200 r / min, and the temperature of the reactor was maintained at 95°C. 38.5 mL of 31 wt% hydrochloric acid and 80 mL of the thiolated solution were added dropwise to the reactor. The above steps of adding hydrochloric acid and the thiolated solution were repeated 4 times. Powdered tungstic acid was filtered while hot and washed twice with 3 wt% hydrochloric acid. The washed powdered tungstic acid was dissolved in ammonia water to obtain an ammonium tungstate solution. The tungsten content in the ammonium tungstate solution was measured as WO3 and was 255.36 g / L. The vanadium content in the ammonium tungstate solution was measured as V2O5 and was 0.031 g / L.

[0120] Comparative Example 5

[0121] A method for purifying tungsten from a vanadium-containing tungstate solution comprises the following steps:

[0122] Take 400 mL of vanadium-containing sodium tungstate solution, in which the tungsten content is measured as WO3 to be 250.68 g / L and the vanadium content is measured as V2O5 to be 1.344 g / L, stir and add dilute hydrochloric acid to adjust the pH to 9;

[0123] Sodium sulfide solution is added to the vanadium-containing sodium tungstate solution and stirred. The molar ratio of sulfur in the added sodium sulfide to vanadium in the vanadium-containing sodium tungstate solution is 2:1. The reaction temperature is 25°C and the sulfidation time is 0.5h. After the reaction is completed, a sulfided liquid is obtained.

[0124] 40 mL of 31 wt% hydrochloric acid and 200 mL of water were added to a reactor, stirred at a speed of 200 r / min, and heated to 95°C. 80 mL of the thiolated solution was added dropwise to the reactor for 12 min. The stirring speed was maintained at 200 r / min, and the temperature of the reactor was maintained at 95°C. 40 mL of 31 wt% hydrochloric acid and 80 mL of the thiolated solution were added dropwise to the reactor. The above steps of adding hydrochloric acid and the thiolated solution were repeated 4 times. Powdered tungstic acid was filtered while hot and washed twice with 3 wt% hydrochloric acid. The washed powdered tungstic acid was dissolved in ammonia water to obtain an ammonium tungstate solution. The tungsten content in the ammonium tungstate solution was measured as WO3 and was 245.06 g / L. The vanadium content in the ammonium tungstate solution was measured as V2O5 and was 0.094 g / L.

[0125] Comparative Example 6

[0126] A method for purifying tungsten from a vanadium-containing tungstate solution comprises the following steps:

[0127] Take 400 mL of vanadium-containing sodium tungstate solution, in which the tungsten content is measured as WO3 to be 250.68 g / L and the vanadium content is measured as V2O5 to be 1.344 g / L, stir and add dilute hydrochloric acid to adjust the pH to 9;

[0128] Sodium sulfide solution is added to the vanadium-containing sodium tungstate solution and stirred. The molar ratio of sulfur in the added sodium sulfide to vanadium in the vanadium-containing sodium tungstate solution is 9:1. The reaction temperature is 25°C and the sulfidation time is 0.5h. After the reaction is completed, a sulfided liquid is obtained.

[0129] 40 mL of 31 wt% hydrochloric acid and 200 mL of water were added to a reactor, stirred at a speed of 200 r / min, and heated to 95°C. 80 mL of the thiolated solution was added dropwise to the reactor for 12 min. The stirring speed was maintained at 200 r / min, and the temperature of the reactor was maintained at 95°C. 40 mL of 31 wt% hydrochloric acid and 80 mL of the thiolated solution were added dropwise to the reactor. The above steps of adding hydrochloric acid and the thiolated solution were repeated 4 times. Powdered tungstic acid was filtered while hot and washed twice with 3 wt% hydrochloric acid. The washed powdered tungstic acid was dissolved in ammonia water to obtain an ammonium tungstate solution. The tungsten content in the ammonium tungstate solution was measured as WO3 and was 246.91 g / L. The vanadium content in the ammonium tungstate solution was measured as V2O5 and was 0.053 g / L.

[0130] The difference between Example 1 and Comparative Example 1 is that Example 1 adopts the operation of sulfurization and batch addition, while Comparative Example 1 does not adopt the operation, and colloidal tungstic acid is obtained. Colloidal tungstic acid has strong adsorption and is difficult to filter. Ammonia solution cannot obtain a high-purity ammonium tungstate solution.

[0131] The difference between Example 1 and Comparative Example 2 is that Example 1 adopts a sulfidation operation, while Comparative Example 2 does not. The vanadium content of the finally obtained ammonium tungstate solution is greater than 0.005 g / L. It can be seen that the vanadium removal effect is not good without the sulfidation operation.

[0132] In Example 4, Example 5, Example 6, Comparative Example 5 and Comparative Example 6, the sulfiding agent was added in a molar ratio of 4:1, 5:1 and 6:1 between the sulfur in the sulfiding agent and the vanadium in the vanadium-containing tungstate solution, respectively, to obtain an ammonium tungstate solution having a vanadium concentration of less than 0.005 g / L. Comparative Examples 5 and 6 were respectively added in a molar ratio of 2:1 and 9:1 between the sulfur in the sulfiding agent and the vanadium in the vanadium-containing tungstate solution, to obtain an ammonium tungstate solution having a vanadium concentration greater than 0.005 g / L. This shows that only by adding the sulfiding agent in a molar ratio of (4 to 6):1 between the sulfur in the sulfiding agent and the vanadium in the vanadium-containing tungstate solution can an ammonium tungstate solution having a vanadium concentration of less than 0.005 g / L be obtained, and the vanadium removal is more thorough.

[0133] In Example 6, Example 7, Example 8, Comparative Example 3 and Comparative Example 4, Example 6, Example 7 and Example 8 were operated at pH 9, 11 and 13, respectively, to obtain ammonium tungstate solutions with a vanadium concentration of less than 0.005 g / L. Comparative Example 3 and Comparative Example 4 were operated at pH 7 and 14, respectively, to obtain ammonium tungstate solutions with a vanadium concentration greater than 0.005 g / L. This shows that only when the solution is in the pH range of 9 to 13 can an ammonium tungstate solution with a vanadium concentration of less than 0.005 g / L be obtained, and the removal of vanadium is more thorough.

[0134] The present invention adopts the scheme of incomplete sulfidation of vanadium. A sulfiding agent is added to the vanadium-containing tungstate solution by a hydrometallurgical method to treat the vanadium therein, so that the vanadium is incompletely sulfided into VO2S. - 、VOS2 - VS3 - One or more of them, using VO2S - 、VOS2 - VS3 - Their different solubilities under acidic conditions will not affect the solution system in the subsequent preparation of tungstic acid. Vanadium exists in the solution, so tungstate can be prepared into tungstic acid without removing the vanadium. After acid washing and ammonia dissolution, the obtained ammonium tungstate solution has a low vanadium content and the purification of tungsten is more thorough.

[0135] The above description is only a preferred embodiment of the present invention and does not limit the patent scope of the present invention. All equivalent structural transformations made by using the contents of the present invention specification under the inventive concept of the present invention, or direct / indirect application in other related technical fields are 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: The steps include: S1. Obtaining a vanadium-containing tungstate solution; S2, adding a sulfiding agent to the vanadium-containing tungstate solution to incompletely sulfide it to obtain a sulfide solution, wherein the vanadium in the vanadium-containing tungstate solution is incompletely sulfide-converted into VO2S - 、VOS2 - VS3 - One or more of the following; S3, mixing the thiolated liquid with dilute hydrochloric acid, stirring and heating; S4. Filter and wash the tungstic acid, and dissolve the tungstic acid with 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.

3. The method for purifying tungsten from a vanadium-containing tungstate solution according to claim 1, characterized in that: The step S3 is specifically as follows: S31, the dilute hydrochloric acid and the thiolated liquid are added in sequence according to a molar ratio of hydrogen ions in the dilute hydrochloric acid to tungsten in the thiolated liquid of (4-5):1; S32, repeating 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, characterized in that: In step S1, the vanadium-containing tungstate solution includes: a vanadium-containing sodium tungstate solution and / or a vanadium-containing potassium tungstate solution, the tungsten content of the vanadium-containing tungstate solution is measured as WO3 and is 150-300 g / L, and the vanadium content of the vanadium-containing tungstate solution is measured as V2O5 and is 0.1-2.0 g / L.

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

6. The method for purifying tungsten from a vanadium-containing tungstate solution according to claim 1, characterized in that: In step S2, the sulfiding 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 sulfidation 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, characterized in that: 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 the 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 measured as V2O5 and is ≤0.005 g / L.