Process for the separation and recovery of high concentrations of molybdenum from a solution containing tungsten and vanadium

Abstract

This invention belongs to the field of metallurgical separation technology and relates to a method for separating and recovering tungsten and vanadium from a high-concentration molybdenum solution. The method includes: adding hydrogen peroxide solution to the liquid to be treated, heating to 60-80°C and maintaining the temperature for 30-60 minutes, then adjusting the pH to 2.5-3.5, and then adding an extractant for extraction to obtain a tungsten-vanadium-containing organic phase. The extractant consists of an amine extractant, tributyl phosphate, an ionic liquid, hyperbranched polyglycerol, and a diluent. The concentration of molybdenum in the liquid to be treated is not less than 150 g / L, the concentration of tungsten is 1-10 g / L, and the concentration of vanadium is 1-10 g / L. This invention aims to solve the technical problems of low efficiency and easy emulsification in the separation of tungsten and vanadium from high-concentration molybdenum solutions.

Description

Technical Field

[0001] This invention belongs to the field of metallurgical separation technology and relates to a method for separating and recovering molybdenum from a high-concentration molybdenum solution containing tungsten and vanadium. Background Technology

[0002] Molybdenum, as an important strategic metal, is widely used in high-end manufacturing fields such as aerospace, electronics and information, metallurgy and chemicals, and new energy. Its purity directly determines the performance of the end materials. In molybdenum smelting, waste molybdenum product recycling, and related chemical production processes, high-concentration molybdenum solutions containing tungsten and vanadium impurities are often generated (molybdenum concentration is usually not less than 150 g / L), with tungsten and vanadium concentrations generally ranging from 1 to 10 g / L. Because molybdenum, tungsten, and vanadium belong to the same group and have highly similar chemical properties, they easily form structurally similar complex ions in high-molybdenum concentration systems, making efficient separation difficult and becoming a key technical bottleneck restricting the preparation of high-purity molybdenum products.

[0003] Currently, industrial methods for separating tungsten and vanadium from molybdenum solutions mainly include precipitation, traditional solvent extraction, and ion exchange. Precipitation involves adjusting the solution pH or adding specific precipitants to cause tungsten and vanadium to precipitate. However, high concentrations of molybdenum ions compete with tungsten and vanadium for reaction sites, resulting in poor precipitation selectivity, incomplete impurity removal, and loss of molybdenum ions due to encapsulation during precipitation. Subsequent solid-liquid separation is also difficult, making it unsuitable for preparing high-purity molybdenum solutions. Traditional solvent extraction, due to its ease of operation and high throughput, has become the mainstream separation technology, commonly using single or combined extractants such as amines and phosphate esters. However, in high-concentration molybdenum systems, traditional extractants lack selectivity for low-content tungsten and vanadium, easily leading to co-extraction of molybdenum with tungsten and vanadium, resulting in decreased molybdenum retention. Furthermore, the high concentration of molybdenum in the solution causes emulsification when the traditional extractant is mixed with the aqueous phase, resulting in slow stratification and significantly impacting production efficiency. Emulsification also easily leads to the loss of the organic phase, increasing processing costs. Although ion exchange can achieve a certain degree of impurity separation, high concentrations of molybdenum ions preferentially occupy the active sites of ion exchange resins, significantly reducing the adsorption capacity of tungsten and vanadium. This results in frequent resin regeneration and long processing cycles, making it only suitable for the purification of low-concentration molybdenum solutions and difficult to adapt to large-scale industrial processing of high-concentration molybdenum systems.

[0004] In summary, existing separation technologies for processing high-concentration molybdenum solutions containing tungsten and vanadium generally suffer from problems such as low separation efficiency, easy emulsification, high molybdenum loss rate, and incomplete impurity removal, failing to meet the demands of industrial production for the efficient and low-cost preparation of high-purity molybdenum products. Therefore, developing a highly selective, efficient, and non-emulsifying technology for the separation and recovery of tungsten and vanadium from high-concentration molybdenum solutions has significant industrial application value and practical significance. Summary of the Invention

[0005] Therefore, the present invention aims to develop a method for separating and recovering tungsten and vanadium from high-concentration molybdenum solutions, intending to solve the technical problems of low efficiency and easy emulsification in the separation of tungsten and vanadium from high-concentration molybdenum solutions.

[0006] On one hand, the present invention relates to a method for separating and recovering high-concentration molybdenum solutions containing tungsten and vanadium, comprising: adding hydrogen peroxide solution to the liquid to be treated, heating to 60-80°C and maintaining for 30-60 min, then adjusting the pH to 2.5-3.5, and then adding an extractant for extraction and separation to obtain an organic phase containing tungsten and vanadium;

[0007] The extractant consists of an amine extractant, tributyl phosphate, an ionic liquid, hyperbranched polyglycerol, and a diluent. The concentration of molybdenum in the liquid to be treated is not less than 150 g / L, the concentration of tungsten is 1~10 g / L, and the concentration of vanadium is 1~10 g / L.

[0008] Furthermore, in the method for separating and recovering high-concentration molybdenum solutions containing tungsten and vanadium provided by the present invention, the mass concentration of the hydrogen peroxide solution is 15-30%.

[0009] Furthermore, in the method for separating and recovering molybdenum from a high-concentration molybdenum solution containing tungsten and vanadium provided by the present invention, the volume ratio of the liquid to be treated to the hydrogen peroxide solution is 1:0.05~0.15.

[0010] Furthermore, in the method for separating and recovering molybdenum from a high-concentration molybdenum solution containing tungsten and vanadium provided by the present invention, the extractant, by volume percentage, consists of 15-25% amine extractant, 5-10% tributyl phosphate, 3-8% ionic liquid, 2-5% hyperbranched polyglycerol, and the remainder being diluent.

[0011] Furthermore, in the method for separating and recovering molybdenum from a high-concentration molybdenum solution containing tungsten and vanadium provided by the present invention, the ionic liquid is selected from at least one of 1-butyl-3-methylimidazolium tetrafluoroborate, 1-octyl-3-methylimidazolium tetrafluoroborate, and 1-butyl-3-methylimidazolium hexafluorophosphate.

[0012] Furthermore, in the method for separating and recovering molybdenum from a high-concentration molybdenum solution containing tungsten and vanadium provided by the present invention, the amine extractant is N-1923 extractant or TOA extractant.

[0013] Furthermore, in the method for separating and recovering molybdenum from a high-concentration molybdenum solution containing tungsten and vanadium provided by the present invention, the diluent is sulfonated kerosene.

[0014] Furthermore, in the method for separation and recovery from a high-concentration molybdenum solution containing tungsten and vanadium provided by the present invention, the O / A ratio of the extracted components is 1:3~5.

[0015] Furthermore, in the method for separating and recovering molybdenum from a high-concentration molybdenum solution containing tungsten and vanadium provided by the present invention, the extraction and separation temperature is 25~35℃.

[0016] Furthermore, in the method for separating and recovering molybdenum from a high-concentration molybdenum solution containing tungsten and vanadium provided by the present invention, the extraction and separation time does not exceed 20 minutes.

[0017] Compared with the prior art, the technical solution provided by the present invention has at least the following beneficial effects or advantages: (1) High separation efficiency and good selectivity. Through the synergistic effect of hydrogen peroxide pretreatment and composite extraction system, tungsten and vanadium can be extracted efficiently and selectively. The extraction rates of tungsten and vanadium can reach more than 97%, while the molybdenum retention rate is higher than 99%. Impurities are thoroughly removed, meeting the requirements for the preparation of high-purity molybdenum.

[0018] (2) Strong anti-emulsification and rapid phase separation. The introduction of ionic liquid and hyperbranched polyglycerol into the extractant significantly enhances the stability of the system. The phase separation time after extraction is short (usually no more than 20 minutes), effectively overcoming the technical problem of easy emulsification of high-concentration molybdenum systems, and is suitable for continuous industrial operation.

[0019] (3) The process is highly adaptable and easy to operate. The method steps are clear, and efficient separation can be achieved under mild conditions. It is suitable for high-concentration solutions with molybdenum concentrations of not less than 150 g / L and has good prospects for industrial application. Detailed Implementation

[0020] The technical solution of the present invention will be described below with reference to embodiments. However, the present invention is not limited to the following embodiments. Unless otherwise specified, the experimental and detection methods described in each embodiment are conventional methods; the reagents and materials described are commercially available unless otherwise specified. Unless otherwise specified, all percentages in the following embodiments refer to weight percentages. Unless otherwise specified, all proportions in the following embodiments refer to weight ratios.

[0021] The liquid to be treated in the following examples is a high-concentration sodium molybdate solution containing tungsten and vanadium, wherein the molybdenum concentration is 150.7 g / L (prepared from sodium molybdate dihydrate), the tungsten concentration is 10.0 g / L (prepared from sodium tungstate dihydrate), and the vanadium concentration is 9.7 g / L (prepared from sodium metavanadate dihydrate).

[0022] Example 1 This embodiment provides a method for separating and recovering high-concentration molybdenum solutions containing tungsten and vanadium.

[0023] Step 1, Oxidation treatment: Slowly add a 20% hydrogen peroxide solution to the filtered liquid to be treated, with a volume ratio of liquid to hydrogen peroxide solution of 1:0.1 and a dropping rate of 2 mL / min. Stir with a magnetic stirrer while adding the solution. After the addition is complete, transfer the mixture to a constant temperature oil bath and heat it to 70°C. Maintain the temperature for 45 minutes while continuously stirring to ensure a complete oxidation reaction.

[0024] Step 2, pH adjustment: Cool the oxidized mixture to room temperature, slowly add 0.5 mol / L dilute sulfuric acid solution to adjust the pH of the solution to 3.0. During the addition process, adjust the stirring rate to 200 r / min to avoid excessive local pH fluctuations.

[0025] Step 3, Extraction and Separation: Transfer the pH-adjusted solution to a 2000mL separatory funnel, add the extractant for extraction and separation; control the extraction temperature at 30℃, the extraction time at 8min, and allow the layers to separate for 14min; the O / A ratio of the extraction and separation is 1:4; the extractant, by volume percentage, consists of 20% N-1923 extractant, 7% tributyl phosphate, 5% 1-butyl-3-methylimidazolium tetrafluoroborate, 3% hyperbranched polyglycerol (branching degree 8~10) and 65% sulfonated kerosene. The extractant is dehydrated before use (add anhydrous calcium chloride, let stand for 24h, and filter to remove water).

[0026] Step 4, Detection Results: After stratification, the upper layer is an organic phase containing tungsten and vanadium, and the lower layer is a high-purity molybdenum solution. Both phases are collected separately, and the concentrations of molybdenum, tungsten, and vanadium in both phases are detected using ICP-OES. The extraction rate and retention rate are calculated as follows: Tungsten extraction rate = (mass of tungsten in the organic phase / total mass of tungsten in the feed solution) × 100%, Vanadium extraction rate = (mass of vanadium in the organic phase / total mass of vanadium in the feed solution) × 100%, Molybdenum retention rate = (mass of molybdenum in the aqueous phase / total mass of molybdenum in the feed solution) × 100%. The results show that the tungsten extraction rate is 98.2%, the vanadium extraction rate is 97.5%, and the molybdenum retention rate is 99.3%, achieving efficient separation and recovery of tungsten, vanadium, and molybdenum. The tungsten and vanadium impurity content in the separated molybdenum solution is less than 0.1 g / L.

[0027] Example 2 This embodiment provides a method for separating and recovering high-concentration molybdenum solutions containing tungsten and vanadium.

[0028] Step 1, Oxidation treatment: Slowly add a 15% hydrogen peroxide solution to the filtered liquid to be treated, with a volume ratio of liquid to hydrogen peroxide solution of 1:0.05 and a dropping rate of 1.5 mL / min. Stir with a magnetic stirrer while adding the solution. After the addition is complete, transfer the solution to a constant temperature oil bath and heat it to 60°C. Maintain the temperature for 30 minutes while stirring continuously to ensure a complete oxidation reaction.

[0029] Step 2, pH adjustment: Cool the oxidized mixture to room temperature, slowly add 0.5 mol / L dilute sulfuric acid solution to adjust the pH of the solution to 2.5. During the addition process, the stirring rate is 200 r / min to avoid local pH fluctuations.

[0030] Step 3, Extraction and Separation: Transfer the liquid to a 2000mL separatory funnel, add the extractant for extraction and separation; control the extraction temperature at 25℃, the extraction time at 20min, and allow it to stand for 18min to separate the layers; the O / A ratio of the extraction and separation is 1:3 (the minimum limit of the claim, i.e., 367mL of extractant is added, and the volume of the liquid is 1100mL); the extractant, by volume percentage, consists of 15% TOA extractant, 5% tributyl phosphate, 3% 1-octyl-3-methylimidazolium tetrafluoroborate, 2% hyperbranched polyglycerol, and 75% sulfonated kerosene, and the extractant is used after dehydration treatment with anhydrous calcium chloride.

[0031] Step 4, Detection Results: After stratification, the organic phase and aqueous phase were collected separately. The concentrations of molybdenum, tungsten, and vanadium in the two phases were detected by ICP-OES. The relevant indicators were calculated: the tungsten extraction rate was 97.1%, the vanadium extraction rate was 96.3%, and the molybdenum retention rate was 99.0%. The contents of tungsten and vanadium impurities in the separated molybdenum solution were both less than 0.2 g / L, achieving effective separation and recovery of tungsten, vanadium, and molybdenum.

[0032] Example 3 This embodiment provides a method for separating and recovering high-concentration molybdenum solutions containing tungsten and vanadium.

[0033] Step 1, Oxidation treatment: Slowly add a 30% hydrogen peroxide solution to the filtered liquid to be treated, with a volume ratio of liquid to hydrogen peroxide solution of 1:0.15 and a dropping rate of 2.5 mL / min. Stir with a magnetic stirrer while adding the solution. After the addition is complete, transfer the solution to a constant temperature oil bath and heat it to 80°C. Maintain the temperature for 60 min while stirring continuously to ensure that the tungsten and vanadium impurities are fully oxidized.

[0034] Step 2, pH adjustment: Cool the oxidized mixture to room temperature, slowly add 0.5 mol / L dilute sulfuric acid solution dropwise to adjust the pH of the solution to 3.5. During the dropwise addition, the stirring rate is 200 r / min to ensure uniform pH adjustment.

[0035] Step 3, Extraction and Separation: Transfer the liquid to a 2000mL separatory funnel, add the extractant for extraction and separation; control the extraction temperature at 35℃, extract for 5min, and allow to stand for 16min to separate the layers; the O / A ratio of the extraction and separation is 1:3; the extractant, by volume percentage, consists of 25% N-1923 extractant, 10% tributyl phosphate, 8% 1-butyl-3-methylimidazolium tetrafluoroborate, 5% hyperbranched polyglycerol and 52% sulfonated kerosene, and is used after dehydration treatment with anhydrous calcium chloride.

[0036] Step 4, Detection Results: After separation, the organic phase and aqueous phase were collected separately. The concentrations of molybdenum, tungsten, and vanadium in the two phases were detected by ICP-OES. The relevant indicators were calculated as follows: the tungsten extraction rate was 98.8%, the vanadium extraction rate was 97.9%, the molybdenum retention rate was 99.5%, and the content of tungsten and vanadium impurities in the separated molybdenum solution was less than 0.08 g / L.

[0037] Example 4 This embodiment provides a method for separating and recovering high-concentration molybdenum solutions containing tungsten and vanadium.

[0038] Step 1, Oxidation treatment: Slowly add a 28% hydrogen peroxide solution to the filtered liquid to be treated, with a volume ratio of liquid to hydrogen peroxide solution of 1:0.12 and a dropping rate of 2.5 mL / min. Stir with a magnetic stirrer while adding the solution. After the addition is complete, transfer the solution to a constant temperature oil bath and heat it to 75°C. Maintain the temperature for 50 min while continuously stirring to ensure that tungsten and vanadium are fully oxidized to an extractable form.

[0039] Step 2, pH adjustment: Cool the oxidized mixture to room temperature, slowly add 0.5 mol / L dilute sulfuric acid solution dropwise to adjust the pH of the solution to 3.2. During the dropwise addition, the stirring rate is 200 r / min to ensure that the pH is stable within the target range.

[0040] Step 3, Extraction and Separation: Transfer the liquid to a 2000mL separatory funnel, add the extractant for extraction and separation; control the extraction temperature at 33℃, the extraction time at 7min, and allow the mixture to stand for 20min to separate into layers; the O / A ratio of the extracted liquid is 1:4.5; the extractant, by volume percentage, consists of 22% N-1923 extractant, 8% tributyl phosphate, 6% mixed ionic liquid (1-butyl-3-methylimidazolium tetrafluoroborate and 1-octyl-3-methylimidazolium tetrafluoroborate mixed in a 1:1 volume ratio, all of which are analytical grade with a purity of 99.5%), 4% hyperbranched polyglycerol, and 60% sulfonated kerosene. The extractant is used after being dehydrated by anhydrous calcium chloride, and the mixed ionic liquid is stirred evenly in advance for later use.

[0041] Step 4, Detection Results: After separation, the organic phase and aqueous phase were collected separately. The concentrations of molybdenum, tungsten, and vanadium in the two phases were detected by ICP-OES. The relevant indicators were calculated as follows: the tungsten extraction rate was 98.5%, the vanadium extraction rate was 97.6%, the molybdenum retention rate was 99.4%, and the content of tungsten and vanadium impurities in the separated molybdenum solution was less than 0.1 g / L.

[0042] Comparative Example 1 This comparative example is the same as Example 3, except that the extractant, by volume percentage, consists of 25% N-1923 extractant, 10% tributyl phosphate, 5% hyperbranched polyglycerol, and 60% sulfonated kerosene.

[0043] The same experimental steps and detection methods were followed as in Example 3. After separation, the organic and aqueous phases were collected, and relevant indicators were calculated by ICP-OES analysis: tungsten extraction rate was 84.6%, vanadium extraction rate was 82.8%, molybdenum retention rate was 98.7%, and the tungsten impurity content in the separated molybdenum solution was 0.85 g / L and the vanadium impurity content was 0.72 g / L. Compared with Example 3, due to the lack of ionic liquid in the extractant, the extraction rates of tungsten and vanadium decreased significantly (by 14.2% and 15.1%, respectively), and the impurity removal effect was significantly worse. This indicates that ionic liquid plays a key role in the selective extraction of tungsten and vanadium, effectively improving separation efficiency and impurity removal. In addition, in Comparative Example 1, emulsification occurred during the extraction and separation step, and the settling time was 64 min.

[0044] Comparative Example 2 This comparative example is the same as Example 3, except that the extractant, by volume percentage, consists of 25% N-1923 extractant, 10% tributyl phosphate, 8% 1-butyl-3-methylimidazolium tetrafluoroborate and 57% sulfonated kerosene.

[0045] The same experimental steps and detection methods were performed as in Example 3. After separation, the organic and aqueous phases were collected, and relevant indicators were calculated by ICP-OES analysis: tungsten extraction rate was 90.3%, vanadium extraction rate was 88.5%, molybdenum retention rate was 98.9%, and the tungsten impurity content in the separated molybdenum solution was 0.42 g / L and the vanadium impurity content was 0.35 g / L. Compared with Example 3, due to the lack of hyperbranched polyglycerol in the extractant, the tungsten and vanadium extraction rates decreased (by 8.5% and 9.4%, respectively), and the impurity removal effect was not good. This indicates that hyperbranched polyglycerol can help improve the stability and separation selectivity of the extractant, and synergistically work with ionic liquids to further optimize the separation effect of tungsten, vanadium, and molybdenum. In addition, in Comparative Example 2, emulsification occurred during the extraction and separation step, and the settling time was 47 min.

[0046] As described above, the basic principles, main features, and advantages of the present invention have been well described. The above embodiments and specifications are merely descriptions of preferred embodiments of the present invention, and the present invention is not limited to the above embodiments. Various changes and improvements made to the technical solutions of the present invention by those skilled in the art without departing from the spirit and scope of the present invention should fall within the protection scope defined by the present invention.

Claims

1. A method for separating and recovering molybdenum from a high-concentration molybdenum solution containing tungsten and vanadium, characterized in that, include: After adding hydrogen peroxide solution to the liquid to be treated, heat to 60~80℃ and maintain for 30~60 min, then adjust the pH to 2.5~3.5, and then add extractant to extract and separate to obtain the organic phase containing tungsten and vanadium; The extractant consists of an amine extractant, tributyl phosphate, an ionic liquid, hyperbranched polyglycerol, and a diluent. The concentration of molybdenum in the liquid to be treated is not less than 150 g / L, the concentration of tungsten is 1~10 g / L, and the concentration of vanadium is 1~10 g / L.

2. The method for separating and recovering molybdenum from a high-concentration molybdenum solution containing tungsten and vanadium according to claim 1, characterized in that, The mass concentration of the hydrogen peroxide solution is 15-30%.

3. The method for separating and recovering molybdenum from a high-concentration molybdenum solution containing tungsten and vanadium according to claim 2, characterized in that, The volume ratio of the liquid to be treated to the hydrogen peroxide solution is 1:0.05~0.

15.

4. The method for separating and recovering molybdenum from a high-concentration molybdenum solution containing tungsten and vanadium according to claim 1, characterized in that, The extractant, by volume percentage, consists of 15-25% amine extractant, 5-10% tributyl phosphate, 3-8% ionic liquid, 2-5% hyperbranched polyglycerol, and the remainder being diluent.

5. The method for separating and recovering molybdenum from a high-concentration molybdenum solution containing tungsten and vanadium according to claim 1, characterized in that, The ionic liquid is selected from at least one of 1-butyl-3-methylimidazolium tetrafluoroborate, 1-octyl-3-methylimidazolium tetrafluoroborate, and 1-butyl-3-methylimidazolium hexafluorophosphate.

6. The method for separating and recovering molybdenum from a high-concentration molybdenum solution containing tungsten and vanadium according to claim 1, characterized in that, The amine extractant is either N-1923 extractant or TOA extractant.

7. The method for separating and recovering molybdenum from a high-concentration molybdenum solution containing tungsten and vanadium according to claim 1, characterized in that, The diluent is sulfonated kerosene.

8. The method for separating and recovering molybdenum from a high-concentration molybdenum solution containing tungsten and vanadium according to claim 1, characterized in that, The O / A ratio of the extracted and separated components is 1:3~5.

9. The method for separating and recovering molybdenum from a high-concentration molybdenum solution containing tungsten and vanadium according to claim 1, characterized in that, The extraction and separation temperature is 25~35℃.

10. The method for separating and recovering molybdenum from a high-concentration molybdenum solution containing tungsten and vanadium according to claim 1, characterized in that, The extraction and separation time shall not exceed 20 minutes.