阅读说明：本技术 一种从水溶液中萃取分离钨、钼的方法 (Method for extracting and separating tungsten and molybdenum from aqueous solution ) 是由 张永强 孙晓 秦茹 车相静 李睿思 张艳娟 陈莹玮 于 2021-01-19 设计创作，主要内容包括：本发明涉及冶金技术领域,提供了一种从水溶液中萃取分离钨、钼的方法。本发明将钨钼混合水溶液、非离子表面活性剂、络合剂、硫酸钠和水混合,将混合液的pH值调节至≤3,得到双水相萃取体系,然后通过搅拌和静置分相,得到上相和下相,上相为富钨的非离子表面活性剂相,下相为富钼水相。在酸性条件下钨主要以仲钨酸B阴离子形态存在,而钼则以仲钼酸根离子存在,本发明利用络合剂与仲钼酸根离子形成亲水性络合物,从而将钼留在水相,仲钨酸B阴离子依靠其较强的疏水性进入非离子表面活性剂相,实现钨和钼的高效分离。本发明的萃取速率快、分离效率高、无乳化现象产生,不使用任何有毒有害、易燃易爆、易挥发的有机溶剂,操作简单,绿色环保。(The invention relates to the technical field of metallurgy, and provides a method for extracting and separating tungsten and molybdenum from an aqueous solution. The method comprises the steps of mixing tungsten-molybdenum mixed aqueous solution, nonionic surfactant, complexing agent, sodium sulfate and water, adjusting the pH value of the mixed solution to be less than or equal to 3 to obtain a double-aqueous-phase extraction system, and then stirring and standing for phase separation to obtain an upper phase and a lower phase, wherein the upper phase is tungsten-rich nonionic surfactant phase, and the lower phase is molybdenum-rich aqueous phase. Under the acidic condition, tungsten mainly exists in a form of paratungstic acid B anion, molybdenum exists in a form of paratolybdate radical ion, a complexing agent and the paratolybdate radical ion form a hydrophilic complex, so that the molybdenum is remained in a water phase, and the paratungstic acid B anion enters a nonionic surfactant phase by virtue of stronger hydrophobicity of the paratungstic acid B anion, so that the high-efficiency separation of the tungsten and the molybdenum is realized. The method has the advantages of high extraction rate, high separation efficiency, no emulsification phenomenon, no use of any toxic, harmful, flammable, explosive and volatile organic solvent, simple operation, and environmental protection.)

1. A method for extracting and separating tungsten and molybdenum from an aqueous solution is characterized by comprising the following steps:

(1) mixing a tungsten-molybdenum mixed aqueous solution, a nonionic surfactant, a complexing agent, sodium sulfate and water to obtain a mixed solution, and adjusting the pH value of the mixed solution to be less than or equal to 3 to obtain a double-water-phase extraction system; tungsten in the tungsten-molybdenum mixed aqueous solution exists in the form of paratungstic acid B;

(2) and sequentially stirring and standing the aqueous two-phase extraction system for phase splitting to obtain an upper phase and a lower phase, wherein the upper phase is a tungsten-rich nonionic surfactant phase, and the lower phase is a molybdenum-rich aqueous phase.

2. The method of claim 1, wherein the molybdenum in the mixed aqueous solution of tungsten and molybdenum is present in the form of molybdate.

3. The method of claim 1, wherein the non-ionic surfactant comprises a polyethylene glycol and/or propylene glycol block polyether.

4. The method of claim 3, wherein the polyethylene glycol comprises polyethylene glycol 4000 and/or polyethylene glycol 2000; the propylene glycol block polyether is L35.

5. The method of claim 1, wherein the complexing agent comprises sodium tartrate and/or sodium citrate.

6. The method according to claim 1, 2 or 5, wherein the mass fraction of the nonionic surfactant, the mass fraction of the tungsten element, the mass fraction of the molybdenum element, the mass fraction of the complexing agent and the mass fraction of the sodium sulfate in the mixed solution are respectively 10% to 30%, 1.0% to 3.0%, 0.1% to 2.0%, 3% to 6% and 5% to 8%, respectively.

7. The method according to claim 1, wherein the reagent for adjusting the pH value of the mixed solution is one or more of sulfuric acid, hydrochloric acid and nitric acid.

8. The method according to claim 1, wherein the stirring time is 30-60 min, and the stirring temperature is 60-80 ℃.

9. The method according to claim 1, wherein the standing phase separation time is 60-120 min, and the temperature of the standing phase separation is 60-80 ℃.

Technical Field

The invention relates to the technical field of metallurgy, in particular to a method for extracting and separating tungsten and molybdenum from an aqueous solution.

Background

Tungsten and molybdenum, both of which are rare high-melting point metals, are indispensable parts in industrial development. Both of them have good high-temperature strength, wear resistance, corrosion resistance, heat and electricity conduction, low thermal expansion coefficient, stable chemical properties and other characteristics, so that they are widely used in many technical fields, such as metallurgy, petrochemical industry, welding, electronics, aerospace and other fields. The application field of tungsten and molybdenum is continuously expanded along with the development of science and technology, and the prospect is very wide.

Tungsten, which is reputed by the "dental industry" reputation, is known for its high melting point and high hardness, and we have most contacted the filaments in everyday life lamps and automotive lamps for tungsten products, but the use of metallic tungsten is by no means limited thereto and is also an internationally important strategic metal. Tungsten ore, which is known as "heavy stone" in ancient times, is mostly used for smelting steel and iron, and tungsten and alloys are widely used in modern technology and in metal cutting tools. The tungsten carbide alloy is used for manufacturing wear-resistant parts, and the service life of the wear-resistant parts can be prolonged. Tungsten alloy steels are used to make wear, strike and corrosion resistant structural materials for high speed drill bits, cutting tools and machinery. High tungsten content specific weight alloys for use in balance and counterbalance systems for aircraft, inertial rotating elements and gyroscopic rotors in instrumentation systems, and medical and chemical radioisotope (cobalt 60) containers, among others. Other compounds of tungsten are also used in paints, lacquers, rubbers, textiles, petroleum, chemical and other applications.

Molybdenum has small expansion coefficient, large electric conductivity and good heat-conducting property, and in the metallurgical industry, molybdenum can be used as an additive for producing various alloy steels and can be combined with tungsten, nickel, cobalt, zirconium, titanium, vanadium, rhenium and the like to form high-grade alloy so as to improve the high-temperature strength, the wear resistance and the corrosion resistance of the alloy. The molybdenum and the molybdenum alloy are also quite stable to most of liquid metal, non-metallic slag and molten glass, so that the molybdenum and the molybdenum alloy have wide application and good prospect in the fields of metallurgy, agriculture, chemical industry, aerospace and the like.

With the continuous development of scientific technology, the global demand of two metals is gradually increased, and researchers are concerned about the problem of recovering tungsten and molybdenum from different sources due to the limited ore resources, and aqueous solutions containing tungsten and molybdenum are usually generated in the tungsten ore extraction metallurgy process and the tungsten-molybdenum alloy waste recovery process. However, due to lanthanide contraction, molybdenum (VI) and tungsten (VI) ions have nearly the same ionic radius, which makes the two ions very similar in chemical properties, thereby causing great difficulty in their selective separation. Therefore, the separation of molybdenum and tungsten has always been a technical challenge for separation researchers in extractive metallurgy.

Currently, some tungsten-molybdenum extraction separation methods reported in the art are as follows: in patent 201910054703.5, trithiocyanuric acid is first sulfurized with a molybdenum-containing tungstate solution, and then a weakly basic anion exchange resin is used for ion exchange adsorption of thiomolybdate, thereby obtaining a tungstate solution; desorbing the thiomolybdate-loaded weak-base anion exchange resin by using an alkaline desorption solution to obtain a molybdate solution.

In patent 201910246806.1, firstly, adding acid to a high-concentration tungsten-molybdenum solution to adjust the pH value to 6-9, then adding ammonium salt, stirring until the ammonium salt is completely dissolved, standing for a period of time at room temperature, and filtering to obtain a sodium ammonium paratungstate double salt precipitate. Adding acid at normal temperature and filtering to prepare tungstic acid; the filtered mother liquor is ammonium molybdate solution, and ammonium tetramolybdate is prepared by acid precipitation.

In patent 201910988146.4, ethyl thioglycolate is added to a molybdenum-containing tungstate solution to perform a sulfurization reaction of molybdate radicals, the molybdate sulfide radicals are extracted and separated by using an organic phase containing a quaternary ammonium extractant, and the organic phase carrying the molybdate sulfide radicals is subjected to a back extraction separation by using an alkaline solution to obtain a molybdenum-containing solution.

In patent 202010059970.4, quaternary ammonium salt is added into a tungsten molybdate solution as a stabilizer (the stabilizer can stabilize molybdate ions in the tungsten molybdate solution, so that the efficiency of a precipitator is improved, the separation efficiency of tungsten and molybdenum is improved), the pH value is adjusted to 8-11, and then divalent manganese salt is added as the precipitator, and solid-liquid separation is performed after reaction.

In patent 201610333695.4, a molybdenum-tungsten mixed solution is sulfurized, an organic phase containing a primary amine extractant is used for extraction and separation, and a negative molybdenum organic phase is washed and then subjected to back extraction and separation by using an alkaline solution to obtain a molybdate solution.

From the above, the tungsten and molybdenum separation in the field mainly adopts precipitation method, ion exchange method, solvent extraction method, etc. Among them, the precipitation method cannot realize deep separation of tungsten and molybdenum, and cannot obtain a product with high purity. The ion exchange method can deeply separate tungsten and molybdenum, but the cost is high. The solvent extraction separation method is a mature tungsten-molybdenum separation technology applied in industry at present, but most of solvents are organic solvents, so that the method has great harm to human health and can cause environmental pollution.

Disclosure of Invention

In view of the above, the present invention provides a method for extracting and separating tungsten and molybdenum from an aqueous solution, which is efficient, green, and simple to operate.

In order to achieve the above object, the present invention provides the following technical solutions:

a method for extracting and separating tungsten and molybdenum from an aqueous solution comprises the following steps:

(1) mixing a tungsten-molybdenum mixed aqueous solution, a nonionic surfactant, a complexing agent, sodium sulfate and water to obtain a mixed solution, and adjusting the pH value of the mixed solution to be less than or equal to 3 to obtain a double-water-phase extraction system; tungsten in the tungsten-molybdenum mixed aqueous solution exists in the form of paratungstic acid B;

(2) and sequentially stirring and standing the aqueous two-phase extraction system for phase splitting to obtain an upper phase and a lower phase, wherein the upper phase is a tungsten-rich nonionic surfactant phase, and the lower phase is a molybdenum-rich aqueous phase.

Preferably, the molybdenum in the tungsten-molybdenum mixed aqueous solution exists in the form of molybdate.

Preferably, the nonionic surfactant comprises a polyethylene glycol and/or propylene glycol block polyether.

Preferably, the polyethylene glycol comprises polyethylene glycol 4000 and/or polyethylene glycol 2000; the propylene glycol block polyether is L35.

Preferably, the complexing agent comprises sodium tartrate and/or sodium citrate.

Preferably, in the mixed solution, the mass fraction of the nonionic surfactant is 10-30%, the mass fraction of the tungsten element is 1.0-3.0%, the mass fraction of the molybdenum element is 0.1-2.0%, the mass fraction of the complexing agent is 3-6%, and the mass fraction of the sodium sulfate is 5-8%.

Preferably, the reagent for adjusting the pH value of the mixed solution is one or more of sulfuric acid, hydrochloric acid and nitric acid.

Preferably, the stirring time is 30-60 min, and the stirring temperature is 60-80 ℃.

Preferably, the standing phase separation time is 60-120 min, and the standing phase separation temperature is 60-80 ℃.

The invention provides a method for extracting and separating tungsten and molybdenum from an aqueous solution, which comprises the following steps: (1) mixing a tungsten-molybdenum mixed aqueous solution, a nonionic surfactant, a complexing agent, sodium sulfate and water to obtain a mixed solution, and adjusting the pH value of the mixed solution to be less than or equal to 3 to obtain a double-water-phase extraction system; tungsten in the tungsten-molybdenum mixed aqueous solution exists in the form of paratungstic acid B; (2) and sequentially stirring and standing the aqueous two-phase extraction system for phase splitting to obtain an upper phase and a lower phase, wherein the upper phase is a tungsten-rich nonionic surfactant phase, and the lower phase is a molybdenum-rich aqueous phase. Under acidic condition (pH is less than or equal to 3), tungsten exists mainly in a high polymeric state ion form (secondary tungstic acid B anion, chemical formula is H₂W₁₂O₄₂ ¹⁰-) and molybdenum as a paramolybdate ion (H)₂Mo₇O₂₄ ^4-) In the method, the complexing agent and the para-molybdate radical ions form a hydrophilic complex, so that molybdenum is left in a water phase, and para-tungstic acid B anions enter a nonionic surfactant phase by virtue of stronger hydrophobicity, so that the high-efficiency separation of tungsten (W) and molybdenum (VI) is realized. The invention has the advantages of high extraction rate, high separation efficiency, no emulsification phenomenon, and no use of any toxic, harmful, flammable, explosive and volatile organic compoundsThe solvent is simple to operate, and is green and environment-friendly. The results of the examples show that the method provided by the invention has higher extraction efficiency, the single-stage extraction rate of tungsten (W) in the upper phase is more than 93%, the single-stage extraction rate of molybdenum (VI) is less than 18%, only a small amount of molybdenum enters the upper phase, and the tungsten-molybdenum separation factor can reach 74.05 at most.

Detailed Description

The invention provides a method for extracting and separating tungsten and molybdenum from an aqueous solution, which comprises the following steps:

(1) mixing a tungsten-molybdenum mixed aqueous solution, a nonionic surfactant, a complexing agent, sodium sulfate and water to obtain a mixed solution, and adjusting the pH value of the mixed solution to be less than or equal to 3 to obtain a double-water-phase extraction system; tungsten in the tungsten-molybdenum mixed aqueous solution exists in the form of paratungstic acid B;

(2) and sequentially stirring and standing the aqueous two-phase extraction system for phase splitting to obtain an upper phase and a lower phase, wherein the upper phase is a tungsten-rich nonionic surfactant phase, and the lower phase is a molybdenum-rich aqueous phase.

The method comprises the step of mixing tungsten and molybdenum mixed aqueous solution, a nonionic surfactant, a complexing agent, sodium sulfate and water to obtain mixed solution. In the invention, the tungsten in the tungsten-molybdenum mixed solution is paratungstic acid B (H)₂W₁₂O₄₂ ^10-) In the form of molybdate, the molybdenum is preferably in the form of molybdate (MoO)₄ ^2-) In particular in the form of sodium molybdate; in a specific embodiment of the present invention, the tungsten-molybdenum mixed aqueous solution may specifically be a tungsten-molybdenum mixed aqueous solution generated in a tungsten ore extraction metallurgy process or a tungsten-molybdenum alloy scrap recovery process. In the specific embodiment of the invention, the aqueous solution of paratungstic acid B and the aqueous solution of sodium tungstate are mixed to simulate the tungsten-molybdenum mixed aqueous solution in actual production.

In the embodiment of the invention, if the tungsten in the original mixed aqueous solution of tungsten and molybdenum is paratungstic acid A (W)₇O₂₄ ^6-) In the form of (1), the invention preferably uses active SiO₂Catalyzing the paratungstic acid A in the mixed aqueous solution into paratungstic acid B, and then performing subsequent extraction; in the present invention, if tungsten is present as paratungstic acid AIn the method, the complexing agent and the tungsten and the molybdenum are subjected to a complexing reaction, and most of the tungsten and the molybdenum are left in a water phase finally, so that the tungsten is completely converted into the form of the paratungstic acid B, and then the extraction is carried out, and the separation efficiency and the extraction effect can be improved; the present invention does not require particular conditions for extraction, and methods known to those skilled in the art can be used.

In the present invention, the nonionic surfactant preferably comprises a polyethylene glycol and/or propylene glycol block polyether; the polyethylene glycol comprises polyethylene glycol 4000((PEG4000)) and/or polyethylene glycol 2000((PEG2000)), and the propylene glycol block polyether is preferably L35.

In the present invention, the complexing agent preferably comprises sodium tartrate and/or sodium citrate.

In the present invention, the water is preferably deionized water.

In the embodiment of the present invention, it is preferable that the complexing agent is dissolved in a part of water, the complexing agent aqueous solution is obtained by dissolving sodium sulfate in a part of water to obtain a sodium sulfate aqueous solution, and then the nonionic surfactant, the tungsten-molybdenum mixed aqueous solution, the complexing agent aqueous solution, the sodium sulfate aqueous solution and the remaining water are mixed to obtain a mixed solution. In the present invention, the sodium sulfate has an effect of promoting phase separation of the system.

In the present invention, in the mixed solution, the mass fraction of the nonionic surfactant is preferably 10% to 30%, more preferably 15% to 25%, the mass fraction of the tungsten element is preferably 1.0% to 3.0%, more preferably 1.5% to 2.5%, the mass fraction of the molybdenum element is preferably 0.1% to 2.0%, more preferably 0.5% to 1.5%, the mass fraction of the complexing agent is preferably 3% to 6%, more preferably 4% to 5%, and the mass fraction of the sodium sulfate is preferably 5% to 8%, more preferably 6% to 7%.

And (3) obtaining a mixed solution, and adjusting the pH value of the mixed solution to be less than or equal to 3, preferably to be 1-3, more preferably to be 1.5-2.5 to obtain a double-water-phase extraction system. In the invention, the reagent for adjusting the pH value of the mixed solution is preferably one or more of sulfuric acid, hydrochloric acid and nitric acid; the invention has no special requirements on the concentrations of the sulfuric acid, the hydrochloric acid and the nitric acid,the pH value of the mixed solution can be adjusted to be within a required range. Under the condition that the pH value is less than or equal to 3, the tungsten in the solution is made into paratungstic acid B (H)₂W₁₂O₄₂ ^10-) Is stable in the form of molybdenum in the form of paramolybdate ion (H)₂Mo₇O₂₄ ^4-) The form (2) exists stably.

After the double-water-phase extraction system is obtained, the double-water-phase extraction system is sequentially stirred and kept stand for phase splitting to obtain an upper phase and a lower phase, wherein the upper phase is a tungsten-rich nonionic surfactant phase, and the lower phase is a molybdenum-rich water phase. In the invention, the stirring time is preferably 30-60 min, more preferably 40-50 min, and the stirring temperature is preferably 60-80 ℃, more preferably 65-75 ℃; the time for standing and phase separation is preferably 60-120 min, more preferably 80-100 min, and the temperature for standing and phase separation is preferably 60-80 ℃, more preferably 65-75 ℃. In a specific embodiment of the invention, preferably, the aqueous two-phase extraction system is stirred by a constant-temperature magnetic stirrer at 60-80 ℃, after the stirring is stopped, the system is placed in a constant-temperature water bath kettle, standing phase splitting is carried out under a heat preservation condition, after standing phase splitting, an upper phase and a lower phase are formed, the upper phase is a tungsten-rich nonionic surfactant phase, the lower phase is a molybdenum-rich aqueous phase, and the upper phase and the lower phase can be separated through liquid separation.

During stirring, the complexing agent and the secondary molybdate radical ions form a complex, the complex has strong hydrophilicity, so that molybdenum is left in a water phase, the secondary tungstic acid B has strong hydrophobicity, enters an anionic surfactant phase, and tungsten and molybdenum can be separated by standing and phase splitting.

The technical solution of the present invention will be clearly and completely described below with reference to the embodiments of the present invention.

Example 1

(1) Mixing and stirring uniformly a nonionic surfactant PEG4000, a tungsten-containing aqueous solution (a paratungstic acid B solution), a molybdenum-containing aqueous solution (a sodium molybdate solution), a complexing agent solution (a sodium tartrate solution), a sodium sulfate aqueous solution and deionized water to obtain a mixed solution, wherein the nonionic surfactant PEG4000 accounts for 20 mass percent, the tungsten accounts for 2.0 mass percent, the molybdenum accounts for 0.5 mass percent, the sodium tartrate accounts for 5 mass percent, the sodium sulfate accounts for 6 mass percent, and the pH value of the mixed solution is adjusted to 1.0 by using sulfuric acid with the concentration of 6mol/L to obtain a two-aqueous-phase extraction system;

(2) and (2) putting the aqueous two-phase extraction system obtained in the step (1) into a constant-temperature magnetic stirrer, stirring at the set temperature of 80 ℃ for 30min, standing in a constant-temperature water bath kettle at the temperature of 80 ℃ after stirring, and carrying out phase separation for 120min to obtain an upper phase and a lower phase, wherein the upper phase is a tungsten-rich nonionic surfactant phase, and the lower phase is a molybdenum-rich aqueous phase.

The contents of tungsten and molybdenum in the aqueous phase were measured by an inductively coupled plasma mass spectrometer, and then the extraction rates of tungsten and molybdenum (i.e., the mass percentage of tungsten or molybdenum extracted to the upper phase to the mixed solution) and the separation factors of tungsten and molybdenum were calculated, resulting in a tungsten extraction rate of 93.03% and a molybdenum extraction rate of 23.39%, and a tungsten-molybdenum separation factor of 47.48 (separation factor: distribution coefficient of W/distribution coefficient of Mo, distribution coefficient: upper phase metal concentration/lower phase metal concentration).

Example 2

(1) Mixing and stirring uniformly a nonionic surfactant PEG2000, a tungsten-containing aqueous solution (a paratungstic acid B solution), a molybdenum-containing aqueous solution (a sodium molybdate solution), a complexing agent solution (a sodium citrate solution), a sodium sulfate aqueous solution and deionized water to obtain a mixed solution, wherein the nonionic surfactant PEG2000 accounts for 20 mass percent, the tungsten accounts for 2.0 mass percent, the molybdenum accounts for 0.5 mass percent, the sodium citrate accounts for 3 mass percent, the sodium sulfate accounts for 8 mass percent, and the pH value of the mixed solution 1 is adjusted to 2.0 by using sulfuric acid with the concentration of 6mol/L to obtain a double-aqueous-phase extraction system;

(2) and (2) putting the aqueous two-phase extraction system obtained in the step (1) into a constant-temperature magnetic stirrer, stirring at the set temperature of 70 ℃ for 60min, standing in a constant-temperature water bath at the temperature of 70 ℃ after stirring, and carrying out phase separation for 120min to obtain an upper phase and a lower phase, wherein the upper phase is a tungsten-rich nonionic surfactant phase, and the lower phase is a molybdenum-rich aqueous phase.

The contents of tungsten and molybdenum in the aqueous phase are tested by adopting an inductively coupled plasma mass spectrometer, and then the extraction rates of the tungsten and the molybdenum and the separation factor of the tungsten and the molybdenum are calculated, so that the extraction rate of the tungsten is 93.70%, the extraction rate of the molybdenum is 18.97%, and the separation factor of the tungsten and the molybdenum is 74.05.

Example 3

(1) Mixing and stirring uniformly a non-ionic surfactant L35, a tungsten-containing aqueous solution (a paratungstic acid B solution), a molybdenum-containing aqueous solution (a sodium molybdate solution), a complexing agent solution (a sodium citrate solution), a sodium sulfate aqueous solution and deionized water to obtain a mixed solution, wherein the non-ionic surfactant L35 accounts for 10% by mass, the tungsten accounts for 3.0% by mass, the molybdenum accounts for 0.1% by mass, the sodium citrate accounts for 4% by mass, the sodium sulfate accounts for 7% by mass, and the pH value of the mixed solution is adjusted to 3.0 by using sulfuric acid with the concentration of 6mol/L to obtain a double-aqueous-phase extraction system;

(2) and (2) putting the aqueous two-phase extraction system obtained in the step (1) into a constant-temperature magnetic stirrer, stirring at the set temperature of 80 ℃ for 30min, standing in a constant-temperature water bath kettle at the temperature of 80 ℃ after stirring, and carrying out phase separation for 60min to obtain an upper phase and a lower phase, wherein the upper phase is a tungsten-rich nonionic surfactant phase, and the lower phase is a molybdenum-rich aqueous phase.

The contents of tungsten and molybdenum in the aqueous phase are tested by adopting an inductively coupled plasma mass spectrometer, and then the extraction rates of the tungsten and the molybdenum and the separation factor of the tungsten and the molybdenum are calculated, so that the extraction rate of the tungsten is 93.18 percent, the extraction rate of the molybdenum is 22.09 percent, and the separation factor of the tungsten and the molybdenum is 48.54.

Example 4

(1) Mixing and stirring uniformly a nonionic surfactant PEG4000, a tungsten-containing aqueous solution (a paratungstic acid B solution), a molybdenum-containing aqueous solution (a sodium molybdate solution), a complexing agent solution (a sodium tartrate solution), a sodium sulfate aqueous solution and deionized water to obtain a mixed solution, wherein the nonionic surfactant PEG4000 accounts for 30 mass percent, the tungsten accounts for 1.0 mass percent, the molybdenum accounts for 0.1 mass percent, the sodium tartrate accounts for 6 mass percent, the sodium sulfate accounts for 5 mass percent, and the pH value of the mixed solution is adjusted to 2.0 by using sulfuric acid with the concentration of 6mol/L to obtain a double-aqueous-phase extraction system;

(2) and (2) putting the aqueous two-phase extraction system obtained in the step (1) into a constant-temperature magnetic stirrer, stirring at the set temperature of 60 ℃ for 60min, standing in a constant-temperature water bath at the temperature of 60 ℃ after stirring, and carrying out phase separation for 120min to obtain an aqueous two-phase system with an upper phase of a tungsten-loaded nonionic surfactant phase and a lower phase of a molybdenum-rich aqueous phase.

The contents of tungsten and molybdenum in the water phase are tested by adopting an inductively coupled plasma mass spectrometer, and then the extraction rates of the tungsten and the molybdenum and the separation factor of the tungsten and the molybdenum are calculated, so that the extraction rate of the tungsten is 92.79%, the extraction rate of the molybdenum is 17.39%, and the separation factor of the tungsten and the molybdenum is 67.64.

Example 5

(1) Mixing and stirring uniformly a nonionic surfactant PEG2000, a tungsten-containing aqueous solution (a paratungstic acid B solution), a molybdenum-containing aqueous solution (a sodium molybdate solution), a complexing agent solution (a sodium tartrate solution), a sodium sulfate aqueous solution and deionized water to obtain a mixed solution, wherein the nonionic surfactant PEG2000 accounts for 30 mass percent, the tungsten accounts for 3.0 mass percent, the molybdenum accounts for 2.0 mass percent, the sodium tartrate accounts for 3 mass percent, the sodium sulfate accounts for 8 mass percent, and the pH value of the mixed solution is adjusted to 2.0 by using sulfuric acid with the concentration of 6mol/L to obtain a double-aqueous-phase extraction system;

(2) and (2) putting the aqueous two-phase extraction system obtained in the step (1) into a constant-temperature magnetic stirrer, stirring at the set temperature of 80 ℃ for 30min, standing in a constant-temperature water bath kettle at the temperature of 80 ℃ after stirring, and carrying out phase separation for 120min to obtain an upper phase and a lower phase, wherein the upper phase is a tungsten-rich nonionic surfactant phase, and the lower phase is a molybdenum-rich aqueous phase.

The contents of tungsten and molybdenum in the aqueous phase are tested by adopting an inductively coupled plasma mass spectrometer, and then the extraction rates of the tungsten and the molybdenum and the separation factor of the tungsten and the molybdenum are calculated, so that the extraction rate of the tungsten is 91.56 percent, the extraction rate of the molybdenum is 22.10 percent, and the separation factor of the tungsten and the molybdenum is 48.27.

Example 6

(1) Mixing and stirring uniformly a nonionic surfactant L35, a tungsten-containing aqueous solution (a paratungstic acid B solution), a molybdenum-containing aqueous solution (a sodium molybdate solution), a complexing agent solution (a sodium citrate solution), a sodium sulfate aqueous solution and deionized water to obtain a mixed solution, wherein the nonionic surfactant L35 accounts for 10 mass percent, the tungsten mass percent is 2.0 mass percent, the molybdenum mass percent is 1.0 mass percent, the sodium citrate mass percent is 4 mass percent, the sodium sulfate mass percent is 7 mass percent, and the pH value of the mixed solution is adjusted to 3.0 by using sulfuric acid with the concentration of 6mol/L to obtain a double-aqueous-phase extraction system;

(2) and (2) putting the aqueous two-phase extraction system obtained in the step (1) into a constant-temperature magnetic stirrer, stirring at the set temperature of 70 ℃ for 30min, standing in a constant-temperature water bath at the temperature of 70 ℃ after stirring, and carrying out phase separation for 120min to obtain an upper phase and a lower phase, wherein the upper phase is a tungsten-rich nonionic surfactant phase, and the lower phase is a molybdenum-rich aqueous phase.

The contents of tungsten and molybdenum in the aqueous phase were tested by an inductively coupled plasma mass spectrometer, and then the extraction rates of tungsten and molybdenum and the separation factor of tungsten and molybdenum were calculated, with the results that the extraction rate of tungsten was 91.46%, the extraction rate of molybdenum was 19.37%, and the separation factor of tungsten and molybdenum was 49.89.

Comparative example 1

(1) Mixing and stirring uniformly a nonionic surfactant polyethylene glycol (PEG2000), a tungsten-containing aqueous solution (a paratungstic acid B solution), a molybdenum-containing aqueous solution (a sodium molybdate solution), a sodium sulfate aqueous solution and deionized water to obtain a mixed solution, wherein the nonionic surfactant PEG2000 accounts for 20 mass percent, the tungsten accounts for 2.0 mass percent, the molybdenum accounts for 0.5 mass percent and the sodium sulfate accounts for 10 mass percent in the mixed solution, and the pH value of the mixed solution is adjusted to 3.0 by using sulfuric acid with the concentration of 6mol/L to obtain a double-aqueous-phase extraction system;

(2) and (2) putting the mixed system in the step (1) into a constant-temperature magnetic stirrer for stirring, setting the temperature to be 40 ℃, stirring for 30min, standing in a constant-temperature water bath kettle at 40 ℃ after stirring, and carrying out phase separation for 60min to obtain an upper phase and a lower phase.

The contents of tungsten and molybdenum in the aqueous phase are tested by adopting an inductively coupled plasma mass spectrometer, and then the extraction rates of the tungsten and the molybdenum and the separation factor of the tungsten and the molybdenum are calculated, so that the extraction rate of the tungsten is 98.65 percent, the extraction rate of the molybdenum is 97.48 percent, and the separation factor of the tungsten and the molybdenum is 1.36.

Comparative example 2

(1) Mixing and stirring uniformly a non-ionic surfactant propylene glycol block polyether (L35), a tungsten-containing aqueous solution (a solution of paratungstic acid B), a molybdenum-containing aqueous solution (a solution of sodium molybdate), a sodium sulfate aqueous solution and deionized water to obtain a mixed solution, wherein the non-ionic surfactant L35 accounts for 20% by mass, the tungsten accounts for 2.0% by mass, the molybdenum accounts for 0.5% by mass and the sodium sulfate accounts for 10% by mass, and the pH value of the mixed solution is adjusted to 3.0 by using sulfuric acid with the concentration of 6mol/L to obtain a double-aqueous-phase extraction system;

(2) and (2) putting the aqueous two-phase extraction system obtained in the step (1) into a constant-temperature magnetic stirrer for stirring, setting the temperature to be 40 ℃, stirring for 30min, standing in a constant-temperature water bath kettle at 40 ℃ after stirring, and carrying out phase separation for 60min to obtain an upper phase and a lower phase.

The contents of tungsten and molybdenum in the aqueous phase are tested by adopting an inductively coupled plasma mass spectrometer, and then the extraction rates of the tungsten and the molybdenum and the separation factor of the tungsten and the molybdenum are calculated, so that the extraction rate of the tungsten is 98.33 percent, the extraction rate of the molybdenum is 97.17 percent, and the separation factor of the tungsten and the molybdenum is 1.66 percent.

Comparative example 3

(1) Mixing and stirring uniformly nonionic surfactant polyethylene glycol octyl phenyl ether (Triton X-100), a tungsten-containing aqueous solution (a solution of paratungstic acid B), a molybdenum-containing aqueous solution (a solution of sodium molybdate), a sodium sulfate aqueous solution and deionized water to obtain a mixed solution, wherein the mass fraction of the nonionic surfactant polyethylene glycol octyl phenyl ether in the mixed solution is 20%, the mass fraction of tungsten is 2.0%, the mass fraction of molybdenum is 0.5%, the mass fraction of sodium sulfate is 10%, and regulating the pH value of the mixed solution 1 to be 6.60 by using sulfuric acid with the concentration of 6mol/L to obtain a double-water-phase extraction system;

(2) and (2) putting the aqueous two-phase extraction system obtained in the step (1) into a constant-temperature magnetic stirrer for stirring, setting the temperature to be 40 ℃, stirring for 30min, standing in a constant-temperature water bath kettle at 40 ℃ after stirring, and carrying out phase separation for 60min to obtain an upper phase and a lower phase.

The contents of tungsten and molybdenum in the aqueous phase are tested by adopting an inductively coupled plasma mass spectrometer, and then the extraction rates of the tungsten and the molybdenum and the separation factor of the tungsten and the molybdenum are calculated, so that the extraction rate of the tungsten is 98.64 percent, the extraction rate of the molybdenum is 97.73 percent, and the separation factor of the tungsten and the molybdenum is 0.96 percent.

Comparative example 4

(1) Mixing and stirring uniformly a nonionic surfactant polyethylene glycol (PEG2000), a tungsten-containing aqueous solution (a solution of paratungstic acid A), a molybdenum-containing aqueous solution (a solution of sodium molybdate), a complexing agent solution (a solution of sodium citrate), a sodium sulfate aqueous solution and deionized water to obtain a mixed solution, wherein the nonionic surfactant PEG2000 accounts for 20 mass percent, the tungsten accounts for 2.0 mass percent, the molybdenum accounts for 0.5 mass percent, the sodium citrate accounts for 3 mass percent, the sodium sulfate accounts for 8 mass percent, and sulfuric acid with the concentration of 6mol/L is used for adjusting the pH value of the mixed solution to 3.0 to obtain a double-aqueous-phase extraction system;

(2) and (2) putting the aqueous two-phase extraction system obtained in the step (1) into a constant-temperature magnetic stirrer for stirring, setting the temperature at 80 ℃, stirring for 30min, standing in a constant-temperature water bath kettle at 80 ℃ after stirring, and carrying out phase separation for 60min to obtain an upper phase and a lower phase.

The contents of tungsten and molybdenum in the aqueous phase are tested by adopting an inductively coupled plasma mass spectrometer, and then the extraction rates of the tungsten and the molybdenum and the separation factor of the tungsten and the molybdenum are calculated, so that the extraction rate of the tungsten is 16.09%, the extraction rate of the molybdenum is 4.45%, and the separation factor of the tungsten and the molybdenum is 1.94.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.