A tungsten extractant, a preparation method thereof and a method for extracting and separating tungsten

Abstract

The application provides a tungsten extractant, a preparation method of the tungsten extractant and a method for extracting and separating tungsten, and belongs to the field of metal extraction and separation in hydrometallurgy. The extractant is composed of a double secondary amine, a double phosphorus oxide and a diluent. The double secondary amine has a unique space structure and alkalinity. The double phosphorus oxide has different chemical structures and properties compared with P204. The synergistic effect of the double secondary amine and the double phosphorus oxide can be used to have high selectivity to tungstate in the extraction process. The tungstate containing molybdenum metal can be directly extracted, so that high-purity tungstate products are obtained by purification and separation. The extractant provided by the application does not need to be pretreated by saponification and the like, and does not need to add acid or alkali. The use of acid and alkali and the like is reduced, the environment is friendly, the requirement for equipment is low, the economy is good, the extraction process is simple and efficient. Different extractant formulations can be selected for different tungsten-molybdenum salt systems, and the extractant is flexible and changeable.

Description

Technical Field

[0001] This invention relates to the field of metal extraction and separation in hydrometallurgy, and particularly to a tungsten extractant, its preparation method, and a method for extracting and separating tungsten. Background Technology

[0002] Tungsten possesses a high melting point, high thermal stability, high hardness, high strength, strong heat and corrosion resistance, and good thermal and electrical conductivity, making it an indispensable additive in the steel industry. Tungsten metal can be used as an alloying element in the production of various alloy steels to improve their corrosion resistance. Tungsten is also an excellent chemical and petroleum catalyst, frequently used in various chemical reactions to catalyze both inorganic and organic reactions. Tungsten oxides can be used in solar cells, photocatalysis, water splitting, and electroluminescent devices. With the advancement of human technology, the application fields of tungsten continue to expand, and its application prospects are very broad.

[0003] my country accounts for approximately 80% of the world's tungsten metallurgical output. However, high-quality wolframite resources are gradually being depleted, and while scheelite reserves are large, the vast majority are complex polymetallic minerals, making it difficult to extract high-purity tungsten. Tungsten and molybdenum often coexist in mineral deposits and metallurgical intermediates. Due to their very similar chemical properties, separating tungsten and molybdenum is extremely difficult.

[0004] In the separation and purification of tungsten and molybdenum, removing trace amounts of molybdenum from tungsten solutions has always been a focus of research. Currently, the main methods for tungsten-molybdenum separation include precipitation, ion exchange, and solvent extraction. Among these, solvent extraction offers advantages such as high separation efficiency, large throughput, low production cost, and high product purity, making it increasingly popular in industry. For example, patent CN102140578B describes a tungsten-molybdenum separation process involving the cooling and crystallization of ammonium tetrathiomolybdate from a high-concentration molybdenum ammonium tungstate solution. The ammonium tungstate solution is first subjected to sulfidation treatment, causing molybdenum in the solution to preferentially form ammonium tetrathiomolybdate. Without adding any other chemical reagents, by lowering the solution temperature, ammonium tetrathiomolybdate preferentially precipitates, while tungstate does not precipitate, thus separating and purifying tungsten and molybdenum. Patent CN102925685B discloses a compound solvent for the extraction and separation of tungsten and molybdenum, which consists of a secondary carbon amine and di-(2-ethylhexyl)phosphine. A mixture of acids is used to achieve tungsten-molybdenum separation through sequential extraction, countercurrent washing, and back-extraction. Patent CN103320612B discloses a composite amine-hydroxyoxime extractant for separating tungsten and molybdenum from solutions containing tungsten-molybdate, achieving a high separation coefficient and effectively removing tungsten from sodium molybdate, thus purifying the sodium molybdate solution. Patent CN118272653A discloses the use of an amino-containing neutral phosphine extractant for separating tungsten and molybdenum; this extractant does not require pre-saponification, reducing the use of acid and alkali reagents and improving the economic efficiency of the separation process. However, the above methods suffer from low extraction efficiency, high extractant costs, and large wastewater discharge, severely limiting their industrial application.

[0005] Therefore, how to provide a highly efficient, economical, and environmentally friendly extractant for the separation and purification of tungsten and molybdenum has become a pressing technical problem to be solved in this field. Summary of the Invention

[0006] The purpose of this invention is to provide a tungsten extractant and its preparation method, as well as a method for extracting and separating tungsten. The tungsten extractant provided by this invention does not require saponification or activation of the extractant, nor does it require the use of acids, alkalis, or oxidants when extracting and separating tungsten. At the same time, the extraction rate of tungsten is high and the purity is high. In addition, the tungsten extractant can be reused after back-extraction, which is green and environmentally friendly.

[0007] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0008] The present invention provides a tungsten extractant comprising, by volume percentage: 1-45% diamine, 10-50% diphosphorus oxide, and the balance being a diluent.

[0009] Preferably, the structure of the di-secondary amine is as follows: The n is 1 to 20; the R 1 and R 2Independently C1~C 30 Alkyl, C3-C8 cycloalkyl and C5-C 15 Any of the aryl groups.

[0010] Preferably, the structure of the diphosphorus oxide is as follows: The n is 1 to 20; the R 3 R 4 R 5 and R 6 Independently C1~C 30 Alkyl, C3-C 10 cycloalkyl and C5-C 19 Any of the aryl groups.

[0011] Preferably, the diluent comprises one or more of the following: white oil, kerosene, sulfonated kerosene, n-hexane, cyclohexane, carbon disulfide, dichloromethane, dichloroethane, chloroform, carbon tetrachloride, methyl acetate, ethyl acetate, octanol, dichlorobenzene, trichlorobenzene, toluene, and xylene.

[0012] The present invention provides a method for preparing the tungsten extractant described in the above technical solution, comprising: mixing a secondary amine, a bisphosphonate oxide and a diluent to obtain the tungsten extractant.

[0013] The present invention also provides a method for extracting and separating tungsten, which involves using a tungsten extractant to perform countercurrent extraction on the extractant, followed by back-extraction to obtain high-purity tungstate; wherein the tungsten extractant is the tungsten extractant described in the above technical solution or the tungsten extractant prepared by the preparation method described in the above technical solution.

[0014] Preferably, the volume ratio of the tungsten extractant to the extractant is 1:(1-10).

[0015] Preferably, the number of stages of the countercurrent extraction is 1 to 10; and the temperature of the countercurrent extraction is 10 to 70°C.

[0016] Preferably, the back-extraction agent used in the back-extraction includes one or more of water, ammonium carbonate solution, ammonium bicarbonate solution, ammonia solution, hydroxylamine solution, sodium carbonate solution, sodium bicarbonate solution, sodium hydroxide solution, and potassium hydroxide solution.

[0017] Preferably, the number of back-extraction stages is 1 to 5; the back-extraction temperature is 15 to 80°C.

[0018] This invention provides a tungsten extractant, comprising, by volume percentage: 1-45% di-secondary amine, 10-50% diphosphorus oxide, and the balance diluent. The extractant consists of di-secondary amine, diphosphorus oxide, and diluent. The di-secondary amine possesses a unique spatial structure and basicity, while the diphosphorus oxide exhibits a different chemical structure and properties compared to P2O4. Utilizing the synergistic effect of the di-secondary amine and diphosphorus oxide, high selectivity for tungstates is achieved during extraction, directly extracting tungstates containing molybdenum metal, thereby purifying and separating high-purity tungstate products. The extractant provided by this invention requires no pretreatment such as saponification, and does not require the addition of acids or alkalis, reducing the use of reagents such as acids and alkalis. It is environmentally friendly, has low equipment requirements, is economical, and the extraction process is simple and efficient. Different extractant formulations can be selected for different tungstomolybdate systems, making the extractant flexible and versatile. Furthermore, the diluent is inexpensive and readily available, resulting in low cost. After back-extraction, the extractant can be reused, making it green and environmentally friendly. This significantly reduces the production and use costs of tungsten extractants, enhances their market competitiveness, and facilitates large-scale industrial application. The results of the examples show that after extracting the mixed solution of sodium tungstate and sodium molybdate using the tungsten extractant provided by the present invention, the extraction rate of sodium tungstate can reach up to 99%, and the purity of sodium tungstate is high with few impurities, and the purity can reach up to 99%. Detailed Implementation

[0019] The present invention provides a tungsten extractant comprising, by volume percentage: 1-45% diamine, 10-50% diphosphorus oxide, and the balance being a diluent.

[0020] The tungsten extractant provided by this invention comprises 1-45% diamine by volume percentage. In this invention, the structure of the diamine is preferably... The n is preferably 1 to 20, more preferably 1 to 10; the R 1 and R 2 Independently preferred are C1 to C 30 Alkyl, C3-C8 cycloalkyl and C5-C 15 Any of the aryl groups, more preferably C4-C5 16 Alkyl, C4-C7 cycloalkyl and C5-C 10 Any of the aryl groups.

[0021] In one embodiment of the present invention, the volume percentage of the secondary amine can be 1%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, or 45%; the secondary amine can be N,N-diphenylethylenediamine (CAS: 150-61-8), N,N-dipentylethylenediamine (CAS: 88619-07-2), N,N-dihexylethylenediamine (CAS: 57413-98-6), 1,2-bis(cyclohexylamino)ethane (CAS: 811-017-5), N,N-diphenylmethyldiamine (CAS: 622-14-0), N,N-diphenylbutyldiamine (CAS: 104-69-8), N,N-dibutylethylenediamine (CAS: 4013-95-0), or N,N-diphenylbutyldiamine (CAS: 13170-61-1).

[0022] The tungsten extractant provided by this invention comprises 10-50% diphosphorus oxide by volume percentage. In this invention, the structure of the diphosphorus oxide is preferably... The n is preferably 1 to 20, more preferably 1 to 10; the R 3 R 4 R 5 and R 6 Independently preferred are C1 to C 30 Alkyl, C3-C 10 cycloalkyl and C5-C 19 Any of the aryl groups, more preferably C4-C5 12 Alkyl, C4-C8 cycloalkyl and C5-C 10 Any of the aryl groups.

[0023] In one embodiment of the present invention, the volume percentage of the bisphosphine oxide can be 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, or 50%; the bisphosphine oxide can be [4-(diphenylphosphoxy)butyl]ethylphenylphosphoxy (CAS: 91656-71-2), dibutyl[4-(butylphenylphosphoxy)butyl]phosphoxy (CAS: 199284-22-5), or butane-1,4-dimethylbis(diphenylphosphine oxide) (CAS: 4151). -27-3), 4-dimethylphosphoxy-1-diphenylphosphoxypropane (CAS: 89807-21-6), 1,2-bis(diphenylphosphoxy)ethane (CAS: 4141-50-8), 4-dimethylphosphoxy-1-diphenylphosphoxypropane (CAS: 89807-21-6), 4-dimethylphosphoxy-1-dimethylphosphoxybutane (CAS: 98543-48-7) or propane-1,3-dimethylbis(diphenylphosphine oxide) (CAS: 16524-41-7).

[0024] The tungsten extractant provided by this invention, by volume percentage, includes the balance being a diluent. In this invention, the diluent preferably comprises one or more of the following: white oil, kerosene, sulfonated kerosene, n-hexane, cyclohexane, carbon disulfide, dichloromethane, dichloroethane, chloroform, carbon tetrachloride, methyl acetate, ethyl acetate, octanol, dichlorobenzene, trichlorobenzene, toluene, and xylene; more preferably, one or more of the following: kerosene, sulfonated kerosene, cyclohexane, carbon disulfide, dichloroethane, chloroform, dichlorobenzene, trichlorobenzene, octanol, toluene, and xylene. In this invention, the diluent primarily provides a liquid environment for the diamine and diphosphorus oxides, facilitating subsequent extraction of tungstates.

[0025] This invention employs a di-secondary amine, diphosphorus oxide, and a diluent as the extractant. The di-secondary amine possesses a unique spatial structure and basicity, while the diphosphorus oxide exhibits a different chemical structure and properties compared to P2O4. Utilizing the synergistic effect of the di-secondary amine and diphosphorus oxide, high selectivity for tungstates is achieved during extraction, directly extracting tungstates containing molybdenum metal, thereby purifying and separating high-purity tungstate products. The extractant provided by this invention requires no pretreatment such as saponification, and does not require the addition of acids or alkalis, reducing the use of reagents such as acids and alkalis. It is environmentally friendly, has low equipment requirements, is economical, and the extraction process is simple and efficient. Different extractant formulations can be selected for different tungstomolybdate systems, making the extractant flexible and versatile. Furthermore, the diluent is inexpensive and readily available, resulting in low cost. After back-extraction, the extractant can be reused, making it green and environmentally friendly. This significantly reduces the production and use costs of tungsten extractants, enhances their market competitiveness, and facilitates large-scale industrial application.

[0026] The present invention also provides a method for preparing the tungsten extractant described in the above technical solution, comprising: mixing a secondary amine, a bisphosphonate oxide and a diluent to obtain the tungsten extractant.

[0027] The present invention does not have any special limitations on the specific operation of the mixing, as long as the secondary amine, the diphosphorus oxide and the diluent are mixed evenly.

[0028] The preparation method provided by this invention is simple, requires no special equipment, and is conducive to its large-scale industrial application.

[0029] The present invention also provides a method for extracting and separating tungsten, which involves using a tungsten extractant to perform countercurrent extraction on the extractant, followed by back-extraction to obtain high-purity tungstate; wherein the tungsten extractant is the tungsten extractant described in the above technical solution or the tungsten extractant prepared by the preparation method described in the above technical solution.

[0030] In this invention, the extraction solution is a mixed solution of tungstate and molybdate; the tungstate is preferably a soluble tungstate, more preferably sodium tungstate; the molybdate is preferably a soluble molybdate, more preferably sodium molybdate; the concentration of tungsten in the mixed solution is preferably 5-300 g / L, and the concentration of molybdenum is preferably 0.1-30 g / L.

[0031] In one embodiment of the present invention, the concentration of tungsten in the mixed solution can be 5 g / L, 10 g / L, 20 g / L, 30 g / L, 50 g / L, 80 g / L, 100 g / L, 150 g / L, 200 g / L, 250 g / L, or 300 g / L; and the concentration of molybdenum in the mixed solution can be 0.1 g / L, 1 g / L, 2 g / L, 3 g / L, 5 g / L, 10 g / L, 15 g / L, 20 g / L, 25 g / L, or 30 g / L.

[0032] In this invention, the volume ratio of the tungsten extractant to the extractant solution is preferably 1:(1-10), more preferably 1:(1-5). By controlling the concentrations of the tungsten extractant and the extractant solution and their volume ratio, this invention ensures that the tungsten extractant extracts the tungsten element from the extractant solution.

[0033] In one embodiment of the present invention, the volume ratio of the tungsten extractant to the extractant solution can be 1:2, 1:3 or 1:4.

[0034] In this invention, the countercurrent extraction is preferably carried out in a mixing and clarification tank, an extraction tower, or a centrifuge. This invention does not impose any special limitations on the specific model or source of the mixing and clarification tank, extraction tower, or centrifuge; commercially available mixing and clarification tanks, extraction towers, or centrifuges well-known to those skilled in the art can be used.

[0035] In this invention, the number of countercurrent extraction stages is preferably 1 to 10; the temperature of the countercurrent extraction is preferably 10 to 70°C. This invention uses countercurrent extraction to extract tungstate solutions, which can improve the extraction rate of tungsten; by controlling the number of countercurrent extraction stages and the temperature, the extraction rate of tungsten can be further improved.

[0036] In one embodiment of the present invention, the number of stages of the countercurrent extraction can be 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10; the temperature of the countercurrent extraction can be 10°C, 15°C, 20°C, 25°C, 30°C, 35°C, 40°C, 45°C, 50°C, 55°C, 60°C, 65°C, or 70°C; and the time of the countercurrent extraction can be 1 min, 3 min, 5 min, 8 min, 10 min, 12 min, 15 min, 18 min, 20 min, 25 min, 30 min, 35 min, or 40 min.

[0037] In this invention, the back-extraction agent used preferably includes one or more of water, ammonium carbonate solution, ammonium bicarbonate solution, ammonia solution, hydroxylamine solution, sodium carbonate solution, sodium bicarbonate solution, sodium hydroxide solution, and potassium hydroxide solution. This invention does not impose any particular limitation on the concentration of the ammonium carbonate solution, ammonium bicarbonate solution, ammonia solution, hydroxylamine solution, sodium carbonate solution, sodium bicarbonate solution, sodium hydroxide solution, and potassium hydroxide solution; based on the technical knowledge of those skilled in the art, any concentration sufficient to back-extract tungstate from the extractant is acceptable. As one embodiment of this invention, the mass concentration of the ammonium carbonate solution, ammonium bicarbonate solution, ammonia solution, hydroxylamine solution, sodium carbonate solution, sodium bicarbonate solution, sodium hydroxide solution, and potassium hydroxide solution can be 5%, 10%, 15%, 20%, 25%, 30%, 35%, or 40%.

[0038] In this invention, the number of back-extraction stages is preferably 1 to 5; the back-extraction temperature is preferably 15 to 80°C. This invention does not have a specific limitation on the back-extraction time; based on the technical knowledge of those skilled in the art, it is sufficient to allow the tungstate to be back-extracted from the extractant. This invention can improve the back-extraction efficiency by controlling the back-extraction temperature.

[0039] In one embodiment of the present invention, the number of back-extraction stages can be 1, 2, 3, 4, or 5; the back-extraction temperature can be 15°C, 20°C, 25°C, 30°C, 35°C, 40°C, 45°C, 50°C, 55°C, 60°C, 65°C, 70°C, 75°C, or 80°C; and the back-extraction time can be 1 min, 2 min, 3 min, 4 min, 5 min, 6 min, 7 min, 8 min, 9 min, or 10 min.

[0040] In this invention, the tungsten extractant after back-extraction is preferably recycled. The tungsten extractant provided by this invention, after back-extraction, contains very few impurities and can be reused for countercurrent extraction of the extractant, thereby reducing production costs.

[0041] The extraction and separation method for tungsten provided by this invention has a simple extraction process with only two steps: extraction and back-extraction. The equipment used is conventional, and the extraction conditions are simple, requiring only room temperature or appropriate heating. The extractant does not require pretreatment such as saponification, which reduces the use of reagents such as acids and alkalis. It has low equipment requirements and is economical.

[0042] The technical solutions of this invention will be clearly and completely described below with reference to the embodiments thereof. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0043] Example 1

[0044] A tungsten extractant, by volume percentage, comprises: 1% diamine, 10% diphosphorus oxide, and the balance being a diluent;

[0045] The secondary amine is N,N-diphenylethylenediamine (CAS: 150-61-8), the bisphosphonate is [4-(diphenylphosphonoxy)butyl]ethylphenylphosphonoxy (CAS: 91656-71-2), and the diluent is sulfonated kerosene.

[0046] The tungsten extractant is prepared by mixing a secondary amine, a phosphorus oxide, and a diluent at room temperature and stirring until homogeneous.

[0047] Application Example 1

[0048] A method for extracting and separating tungsten involves using the tungsten extractant of Example 1 in a centrifugal extractor to perform countercurrent extraction of the extractant solution, followed by back-extraction to obtain high-purity tungstate.

[0049] The extraction solution is a mixed solution of sodium tungstate and sodium molybdate; the concentration of tungsten in the mixed solution is 10 g / L and the concentration of molybdenum is 2 g / L.

[0050] The volume ratio of the tungsten extractant to the extractant solution is 1:1.

[0051] The countercurrent extraction process consists of 4 stages, with a temperature of 20°C and a extraction time of 9 minutes.

[0052] The back-extraction agent used is water, the back-extraction stage is 1, the back-extraction temperature is 20℃, the back-extraction time is 3min, and the tungsten extractant after back-extraction is recycled.

[0053] Example 2

[0054] A tungsten extractant, by volume percentage, comprises: 5% diamine, 20% diphosphorus oxide, and the balance being a diluent;

[0055] The secondary amine is N,N-dipentylethylenediamine (CAS: 88619-07-2), the bisphosphonate is dibutyl[4-(butylphenylphosphoxy)butyl]phosphoxy (CAS: 199284-22-5), and the diluent is xylene;

[0056] The tungsten extractant is prepared by mixing a secondary amine, a phosphorus oxide, and a diluent at room temperature and stirring until homogeneous.

[0057] Application Example 2

[0058] A method for extracting and separating tungsten involves using the tungsten extractant of Example 2 in a centrifugal extractor to perform countercurrent extraction of the extractant solution, followed by back-extraction to obtain high-purity tungstate.

[0059] The extraction solution is a mixed solution of sodium tungstate and sodium molybdate; the concentration of tungsten in the mixed solution is 30 g / L and the concentration of molybdenum is 3 g / L.

[0060] The volume ratio of the tungsten extractant to the extractant solution is 2:1.

[0061] The countercurrent extraction process consists of 5 stages, the temperature is 25°C, and the extraction time is 10 min.

[0062] The back-extraction agent used is an ammonium carbonate solution with a mass concentration of 25%. The back-extraction stage is 2 stages, the back-extraction temperature is 30°C, and the back-extraction time is 2 minutes. The tungsten extractant after back-extraction is recycled.

[0063] Example 3

[0064] A tungsten extractant, by volume percentage, comprises: 15% diamine, 25% diphosphorus oxide, and the balance being a diluent;

[0065] The secondary amine is N,N-dihexylethylenediamine (CAS: 57413-98-6), the bisphosphide is butane-1,4-dimethylbis(diphenylphosphine oxide) (CAS: 4151-27-3), and the diluent is carbon disulfide.

[0066] The tungsten extractant is prepared by mixing a secondary amine, a phosphorus oxide, and a diluent at room temperature and stirring until homogeneous.

[0067] Application Example 3

[0068] A method for extracting and separating tungsten involves using the tungsten extractant of Example 3 in a centrifugal extractor to perform countercurrent extraction on the extractant, followed by back-extraction to obtain high-purity tungstate.

[0069] The extraction solution is a mixed solution of sodium tungstate and sodium molybdate; the concentration of tungsten in the mixed solution is 70 g / L and the concentration of molybdenum is 1 g / L.

[0070] The volume ratio of the tungsten extractant to the extractant solution is 3:1.

[0071] The countercurrent extraction process consists of 7 stages, the temperature is 35°C, and the extraction time is 10 min.

[0072] The back-extraction agent used is ammonia water with a mass concentration of 20%. The back-extraction stage is 1, the back-extraction temperature is 45°C, and the back-extraction time is 2 minutes. The tungsten extractant after back-extraction is recycled.

[0073] Example 4

[0074] A tungsten extractant, by volume percentage, comprises: 20% diamine, 40% diphosphorus oxide, and the balance being a diluent;

[0075] The secondary amine is 1,2-bis(cyclohexylamino)ethane (CAS: 811-017-5), the bisphosphonate is 4-dimethylphosphonoxy-1-diphenylphosphonoxypropane (CAS: 89807-21-6), and the diluent is chloroform;

[0076] The tungsten extractant is prepared by mixing a secondary amine, a phosphorus oxide, and a diluent at room temperature and stirring until homogeneous.

[0077] Application Example 4

[0078] A method for extracting and separating tungsten involves using the tungsten extractant of Example 4 in a centrifugal extractor for countercurrent extraction of the extractant solution, followed by back-extraction to obtain high-purity tungstate.

[0079] The extraction solution is a mixed solution of sodium tungstate and sodium molybdate; the concentration of tungsten in the mixed solution is 75 g / L and the concentration of molybdenum is 13 g / L.

[0080] The volume ratio of the tungsten extractant to the extractant solution is 2:1.

[0081] The countercurrent extraction process consists of 4 stages, with a temperature of 29°C and a extraction time of 6 minutes.

[0082] The back-extraction agent used is hydroxylamine solution with a mass concentration of 30%. The back-extraction stage is 1, the back-extraction temperature is 33°C, and the back-extraction time is 1 min. The tungsten extractant after back-extraction is recycled.

[0083] Example 5

[0084] A tungsten extractant, by volume percentage, comprises: 30% diamine, 50% diphosphorus oxide, and the balance being a diluent;

[0085] The secondary amine is N,N-diphenylmethyldiamine (CAS: 622-14-0), the bisphosphide is 1,2-bis(diphenylphosphoxy)ethane (CAS: 4141-50-8), and the diluent is cyclohexane;

[0086] The tungsten extractant is prepared by mixing a secondary amine, a phosphorus oxide, and a diluent at room temperature and stirring until homogeneous.

[0087] Application Example 5

[0088] A method for extracting and separating tungsten involves using the tungsten extractant of Example 5 in an extraction tower for countercurrent extraction of the extractant solution, followed by back-extraction to obtain high-purity tungstate.

[0089] The extraction solution is a mixed solution of sodium tungstate and sodium molybdate; the concentration of tungsten in the mixed solution is 55 g / L and the concentration of molybdenum is 4 g / L.

[0090] The volume ratio of the tungsten extractant to the extractant solution is 2:1.

[0091] The countercurrent extraction process consists of three stages, with a temperature of 60°C and a extraction time of 10 minutes.

[0092] The back-extraction agent used is a sodium hydroxide solution with a mass concentration of 15%. The back-extraction stage is 1 stage, the back-extraction temperature is 65°C, and the back-extraction time is 1 minute. The tungsten extractant after back-extraction is recycled.

[0093] Example 6

[0094] A tungsten extractant, by volume percentage, comprises: 25% diamine, 46% diphosphorus oxide, and the balance being a diluent;

[0095] The secondary amine is N,N-diphenylbutanediamine (CAS: 104-69-8), the bisphosphonate is 4-dimethylphosphonoxy-1-diphenylphosphonoxypropane (CAS: 89807-21-6), and the diluent is a mixture of chloroform and trichlorobenzene in a volume ratio of 1:1.

[0096] The tungsten extractant is prepared by mixing a secondary amine, a phosphorus oxide, and a diluent at room temperature and stirring until homogeneous.

[0097] Application Example 6

[0098] A method for extracting and separating tungsten involves countercurrent extraction of the extractant to be extracted in an extraction tower using the tungsten extractant of Example 6, followed by back-extraction to obtain high-purity tungstate.

[0099] The extraction solution is a mixed solution of sodium tungstate and sodium molybdate; the concentration of tungsten in the mixed solution is 100 g / L and the concentration of molybdenum is 3 g / L.

[0100] The volume ratio of the tungsten extractant to the extractant solution is 5:1.

[0101] The countercurrent extraction process consists of three stages, with a temperature of 48°C and a extraction time of 20 minutes.

[0102] The back-extraction agent used is a potassium hydroxide solution with a mass concentration of 25%. The back-extraction stage is 1, the back-extraction temperature is 50°C, and the back-extraction time is 5 minutes. The tungsten extractant after back-extraction is recycled.

[0103] Example 7

[0104] A tungsten extractant, by volume percentage, comprises: 45% diamine, 50% diphosphorus oxide, and the balance being a diluent;

[0105] The secondary amine is N,N-dibutylethylenediamine (CAS: 4013-95-0), the bisphosphonate is 4-dimethylphosphonoxy-1-dimethylphosphonoxybutane (CAS: 98543-48-7), and the diluent is a mixture of sulfonated kerosene and dichloroethane in a volume ratio of 2:1.

[0106] The tungsten extractant is prepared by mixing a secondary amine, a phosphorus oxide, and a diluent at room temperature and stirring until homogeneous.

[0107] Application Example 7

[0108] A method for extracting and separating tungsten involves countercurrent extraction of the extractant to be extracted in a mixing and clarifying tank using the tungsten extractant of Example 7, followed by back-extraction to obtain high-purity tungstate.

[0109] The extraction solution is a mixed solution of sodium tungstate and sodium molybdate; the concentration of tungsten in the mixed solution is 240 g / L and the concentration of molybdenum is 25 g / L.

[0110] The volume ratio of the tungsten extractant to the extractant solution is 1:1.

[0111] The countercurrent extraction process consists of 6 stages, with a temperature of 25°C and a extraction time of 15 minutes.

[0112] The back-extraction agent used is a sodium bicarbonate solution with a mass concentration of 20%. The back-extraction process consists of three stages, with a back-extraction temperature of 35°C and a back-extraction time of 3 minutes. The tungsten extractant after back-extraction is recycled.

[0113] Example 8

[0114] A tungsten extractant, by volume percentage, comprises: 40% diamine, 45% diphosphorus oxide, and the balance being a diluent;

[0115] The secondary amine is N,N-diphenylbutanediamine (CAS: 13170-61-1), the bisphosphonate is propane-1,3-dimethylbis(diphenylphosphine oxide) (CAS: 16524-41-7), and the diluent is a mixture of toluene and carbon tetrachloride in a volume ratio of 2:1.

[0116] The tungsten extractant is prepared by mixing a secondary amine, a phosphorus oxide, and a diluent at room temperature and stirring until homogeneous.

[0117] Application Example 8

[0118] A method for extracting and separating tungsten involves countercurrent extraction of the extractant to be extracted in a mixing and clarifying tank using the tungsten extractant of Example 8, followed by back-extraction to obtain high-purity tungstate.

[0119] The extraction solution is a mixed solution of sodium tungstate and sodium molybdate; the concentration of tungsten in the mixed solution is 180 g / L and the concentration of molybdenum is 13 g / L.

[0120] The volume ratio of the tungsten extractant to the extractant solution is 2:1.

[0121] The countercurrent extraction process consists of 6 stages, with a temperature of 25°C and a extraction time of 35 min.

[0122] The back-extraction agent used is an ammonium carbonate solution with a mass concentration of 25%. The back-extraction stage is 2 stages, the back-extraction temperature is 30°C, and the back-extraction time is 10 minutes. The tungsten extractant after back-extraction is recycled.

[0123] The extraction rates and purities of sodium tungstate obtained from Examples 1-8 are shown in Table 1.

[0124] Table 1 shows the extraction rate and purity of sodium tungstate obtained from Application Examples 1-8.

[0125] Example Sodium tungstate extraction rate / % Sodium tungstate purity / % Application Example 1 85 88 Application Example 2 97 98 Application Example 3 99 99 Application Example 4 88 89 Application Example 5 91 90 Application Example 6 91 93 Application Example 7 89 95 Application Example 8 92 99

[0126] The purity was tested using an ICP-MS instrument to determine the content of sodium tungstate and sodium molybdate in the solution, thus obtaining the purity of sodium tungstate.

[0127] As shown in Table 1, after extracting the mixed solution of sodium tungstate and sodium molybdate using the tungsten extractant provided by the present invention, the extraction rate of sodium tungstate is ≥85%, and can reach up to 99%. Sodium tungstate has high purity and few impurities, with a purity of ≥88% and up to 99%. This indicates that the tungsten extractant provided by the present invention can be used for the extraction of tungsten and can achieve a very good extraction effect.

[0128] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A tungsten extractant, comprising, by volume percentage: 1-45% diamine, 10-50% diphosphorus oxide, and the balance being a diluent; The structure of the di-secondary amine is as follows: The n is 1~20; the R 1 and R 2 Independently C1~C 30 Alkyl, C3-C8 cycloalkyl and C5-C 15 Any of the aryl groups, The structure of the diphosphide oxide is as follows: The n is 1~20; the R 3 R 4 R 5 and R 6 Independently C1~C 30 Alkyl, C3~C 10 cycloalkyl and C5~C 19 Any of the aryl groups.

2. The tungsten extractant according to claim 1, characterized in that, The diluent includes one or more of the following: white oil, kerosene, sulfonated kerosene, n-hexane, cyclohexane, carbon disulfide, dichloromethane, dichloroethane, chloroform, carbon tetrachloride, methyl acetate, ethyl acetate, octanol, dichlorobenzene, trichlorobenzene, toluene, and xylene.

3. A method for preparing the tungsten extractant according to any one of claims 1 to 2, comprising: The tungsten extractant is obtained by mixing the diamine, diphosphorus oxide and diluent.

4. A method for extracting and separating tungsten, characterized in that, The extract to be extracted is subjected to countercurrent extraction using a tungsten extractant, followed by back-extraction to obtain high-purity tungstate; the tungsten extractant is the tungsten extractant according to any one of claims 1 to 2 or the tungsten extractant prepared by the preparation method according to claim 3.

5. The method according to claim 4, characterized in that, The volume ratio of the tungsten extractant to the extractant is 1:(1~10).

6. The method according to claim 4, characterized in that, The countercurrent extraction has 1 to 10 stages; the temperature of the countercurrent extraction is 10 to 70°C.

7. The method according to claim 4, characterized in that, The back-extraction agent used in the back-extraction includes one or more of the following: water, ammonium carbonate solution, ammonium bicarbonate solution, ammonia solution, hydroxylamine solution, sodium carbonate solution, sodium bicarbonate solution, sodium hydroxide solution, and potassium hydroxide solution.

8. The method according to claim 4, characterized in that, The number of back-extraction stages is 1 to 5; the back-extraction temperature is 15 to 80°C.

Images