Extracting agent for extracting and separating tungsten and molybdenum and application thereof

Abstract

The invention provides an extracting agent for extracting and separating tungsten and molybdenum and application of the extracting agent, and belongs to the technical field of tungsten and molybdenum separation in hydrometallurgy. The extracting agent for extracting and separating tungsten and molybdenum, provided by the invention, comprises the following components in percentage by volume: 5-35% of bis-secondary amine, 10-45% of monophosphorus oxide and the balance of diluent. The extraction agent provided by the invention comprises the bis-secondary amine and the monophosphorus oxide, and has the advantages of high extraction efficiency, high separation coefficient, high selectivity and the like when a solution containing tungsten and molybdenum is subjected to counter-current extraction by utilizing the synergistic effect of large steric hindrance of the bis-secondary amine and Lewis alkalinity of the monophosphorus oxide. The result of the embodiment shows that the extraction rate of tungsten can reach 97% and the selectivity can reach 99% when the extraction agent provided by the invention is used for performing counter-current extraction on the solution containing tungsten and molybdenum.

Description

Technical Field

[0001] The invention belongs to the technical field of tungsten and molybdenum separation in hydrometallurgy, and specifically relates to an extractant for extracting and separating tungsten and molybdenum and application thereof. Background Art

[0002] Tungsten has high melting point, high thermal stability, high hardness, high strength, strong heat and corrosion resistance, and good thermal and electrical conductivity, and has important applications in many fields. Tungsten is mainly obtained by smelting tungsten ore. Tungsten and molybdenum are transition metal elements. They are close to each other in the periodic table and have similar properties. They are common co-existing elements in minerals. In the separation and purification of tungsten and molybdenum, removing trace amounts of molybdenum in tungsten solutions has always been a very difficult task, and it is also one of the topics that has attracted more and more attention from scientific researchers. The existing tungsten and molybdenum separation methods mainly include precipitation method, ion exchange method and solvent extraction method. Among them, the solvent extraction method has the advantages of high separation efficiency, large processing capacity, low production cost and high product purity, and is increasingly popular in industry. The extractant is the key to solving the separation and purification of tungsten and molybdenum. The extractants in the existing technology, such as complex amine-hydroxyoxime, have defects such as low extraction rate and selectivity. Therefore, there is an urgent need for an extractant with high extraction rate and selectivity for separating tungsten and molybdenum. Summary of the invention

[0003] The purpose of the present invention is to provide an extractant for extracting and separating tungsten and molybdenum and its application. The extractant provided by the present invention has a higher extraction rate and selectivity when separating tungsten and molybdenum.

[0004] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0005] The invention provides an extractant for extracting and separating tungsten and molybdenum, which comprises 5-35% of di-secondary amine, 10-45% of monophosphorus oxide and the remainder of diluent in terms of volume percentage.

[0006] Preferably, the structural formula of the di-secondary amine is as shown in Formula I:

[0007]

[0008] In the formula I, R 1 and R 2 Independently C1~C 25 Alkyl, C3~C 12 Cycloalkyl and C5~C 17 One of the aromatic groups; n is an integer from 1 to 20.

[0009] Preferably, the structural formula of the monophosphorus oxide is as shown in Formula II:

[0010]

[0011] In the formula II, R 3 , R 4 and R 5 Independently C1~C 40 Alkyl, C3~C 20 Cycloalkyl and C5~C 18 One of the aromatic groups.

[0012] Preferably, the diluent comprises one or more of white oil, kerosene, sulfonated kerosene, n-hexane, cyclohexane, carbon disulfide, dichloromethane, dichloroethane, chloroform, carbon tetrachloride, methyl acetate, ethyl acetate, octanol, hexadecanol, dichlorobenzene, trichlorobenzene, toluene and xylene.

[0013] The present invention also provides the use of the extractant for extracting and separating tungsten and molybdenum described in the above technical solution in separating tungsten and molybdenum.

[0014] Preferably, the application comprises the following steps:

[0015] (1) subjecting an extractant for extracting and separating tungsten and molybdenum to countercurrent extraction with a solution containing tungsten and molybdenum to obtain an extract;

[0016] (2) The extract obtained in step (1) is subjected to countercurrent stripping with a stripping agent to obtain a tungsten-containing solution and an extracting agent.

[0017] Preferably, in step (1), the volume ratio of the extractant for extracting and separating tungsten and molybdenum to the solution containing tungsten and molybdenum is (1-5):1.

[0018] Preferably, the number of stages of countercurrent extraction in step (1) is 1 to 15, and the temperature of countercurrent extraction is 10 to 70°C.

[0019] Preferably, the stripping agent in step (2) comprises one or more of water, sodium hydroxide solution, potassium hydroxide solution, aqueous ammonia solution, ammonium carbonate solution, ammonium bicarbonate solution, hydroxylamine solution, sodium carbonate solution and sodium bicarbonate solution.

[0020] Preferably, the number of stages of countercurrent stripping in step (2) is 1 to 3, and the temperature of countercurrent stripping is 15 to 75°C.

[0021] The present invention provides an extractant for extracting and separating tungsten and molybdenum, which comprises 5 to 35% of a di-secondary amine, 10 to 45% of a monophosphorus oxide, and the remainder of a diluent, by volume percentage. The extractant provided by the present invention comprises a di-secondary amine and a monophosphorus oxide, and utilizes the synergistic effect of the large steric hindrance of the di-secondary amine and the Lewis basicity of the monophosphorus oxide to have the advantages of high extraction rate, high separation coefficient, and high selectivity when countercurrent extraction is performed on a solution containing tungsten and molybdenum. The results of the embodiment show that when the extractant provided by the present invention is used to perform countercurrent extraction on a solution containing tungsten and molybdenum, the extraction rate of tungsten can reach 97%, and the selectivity can reach 99%. DETAILED DESCRIPTION

[0022] The invention provides an extractant for extracting and separating tungsten and molybdenum, which comprises 5-35% of di-secondary amine, 10-45% of monophosphorus oxide and the remainder of diluent in terms of volume percentage.

[0023] Unless otherwise specified, the present invention has no particular limitation on the sources of the components, and commercially available products known to those skilled in the art may be used.

[0024] The extractant provided by the present invention comprises 5-35% of di-secondary amine by volume percentage. As an embodiment, the volume percentage of the di-secondary amine can be specifically 5%, 10%, 15%, 20%, 25%, 30% or 35%.

[0025] In the present invention, the structural formula of the di-secondary amine is preferably as shown in Formula I:

[0026]

[0027] In the present invention, in the formula I, R 1 and R 2 Preferably, C1 to C 25 Alkyl, C3~C 12 Cycloalkyl and C5~C 17 As an embodiment, the R 1 and R 2 Specifically, each of them can be independently phenyl, butyl, pentyl, hexyl or cyclohexyl.

[0028] In the present invention, in the formula I, n is preferably an integer from 1 to 20. As an embodiment, n can be specifically 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 or 20.

[0029] The present invention controls the structure and dosage of the di-secondary amine within the above range, and can utilize the large steric hindrance of the di-secondary amine and the synergistic effect of the monophosphorus oxide to further improve the extraction rate, selectivity and separation coefficient.

[0030] The extractant provided by the present invention further comprises 10-45% of monophosphorus oxide by volume percentage. As an embodiment, the volume percentage of the monophosphorus oxide can be specifically 10%, 15%, 20%, 25%, 30%, 35%, 40% or 45%.

[0031] In the present invention, the structural formula of the monophosphorus oxide is preferably as shown in Formula II:

[0032]

[0033] In the present invention, in the formula II, R 3 , R 4 and R 5 Preferably, C1 to C 40 Alkyl, C3~C 20 Cycloalkyl and C5~C 18 As an embodiment, the R 3 , R 4 and R 5 Specifically, they may independently be cyclohexyl, propyl, methyl, ethyl, phenyl, isobutyl, cyclopentyl, butyl or 4-tert-butylcyclohexyl.

[0034] The present invention controls the structure and dosage of the monophosphorus oxide within the above range, and can utilize the synergistic effect of the Lewis basicity of the monophosphorus oxide and the di-secondary amine to further improve the extraction rate, selectivity and separation coefficient.

[0035] Calculated by volume percentage, the extractant provided by the present invention also includes a balance of diluent.

[0036] In the present invention, the diluent preferably includes one or more of white oil, kerosene, sulfonated kerosene, n-hexane, cyclohexane, carbon disulfide, methylene chloride, ethylene dichloride, chloroform, carbon tetrachloride, methyl acetate, ethyl acetate, octanol, hexadecanol, dichlorobenzene, trichlorobenzene, toluene and xylene. The present invention controls the amount and type of the diluent within the above range, so that each component can be fully dissolved.

[0037] The invention adopts di-secondary amine and monophosphorus oxide as extractants, and utilizes the synergistic effect of the large steric hindrance of the di-secondary amine and the Lewis basicity of the monophosphorus oxide to perform countercurrent extraction on a solution containing tungsten and molybdenum, thereby having the advantages of high extraction rate, high separation coefficient and high selectivity; at the same time, the extractant has the advantages of low price and small organic phase loss, and is an extractant with great industrial use.

[0038] The present invention has no special limitation on the preparation method of the extractant for extracting and separating tungsten and molybdenum, as long as the components can be mixed evenly.

[0039] The present invention also provides the use of the extractant for extracting and separating tungsten and molybdenum described in the above technical solution in separating tungsten and molybdenum.

[0040] In the present invention, the application preferably comprises the following steps:

[0041] (1) subjecting an extractant for extracting and separating tungsten and molybdenum to countercurrent extraction with a solution containing tungsten and molybdenum to obtain an extract;

[0042] (2) The extract obtained in step (1) is subjected to countercurrent stripping with a stripping agent to obtain a tungsten-containing solution and an extracting agent.

[0043] The present invention preferably performs countercurrent extraction on the extractant for extracting and separating tungsten and molybdenum with the solution containing tungsten and molybdenum to obtain an extract.

[0044] The present invention has no special limitation on the source of the solution containing tungsten and molybdenum. The solution containing tungsten and molybdenum from which tungsten and molybdenum need to be separated can be selected according to actual needs.

[0045] In the present invention, the volume ratio of the extractant for extracting and separating tungsten and molybdenum to the solution containing tungsten and molybdenum is preferably (1-5): 1. As an embodiment, the volume ratio of the extractant for extracting and separating tungsten and molybdenum to the solution containing tungsten and molybdenum can be specifically 1:1, 1:2, 1:3, 1:4 or 1:5.

[0046] In the present invention, the number of stages of the countercurrent extraction is preferably 1 to 15. As an embodiment, the number of stages of the countercurrent extraction can be specifically 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14 or 15.

[0047] In the present invention, the temperature of the countercurrent extraction is preferably 10-70° C. As an embodiment, the temperature of the countercurrent extraction can be specifically 10° C., 20° C., 30° C., 40° C., 50° C., 60° C. or 70° C.

[0048] In the present invention, the countercurrent extraction time is preferably 5 to 40 minutes.

[0049] The present invention controls various parameters during countercurrent extraction within the above ranges, which can further improve the extraction rate.

[0050] In the present invention, in the countercurrent extraction process, tungsten is extracted into the extractant to obtain an extract.

[0051] After obtaining the extract, the present invention preferably performs countercurrent stripping of the extract with a stripping agent to obtain a tungsten-containing solution and an extracting agent.

[0052] In the present invention, the stripping agent preferably includes one or more of water, sodium hydroxide solution, potassium hydroxide solution, aqueous ammonia solution, ammonium carbonate solution, ammonium bicarbonate solution, hydroxylamine solution, sodium carbonate solution and sodium bicarbonate solution.

[0053] In the present invention, the mass concentration of the sodium hydroxide solution is preferably 10-35%; the mass concentration of the potassium hydroxide solution is preferably 10-35%; the mass concentration of the ammonia solution is preferably 10-30%; the mass concentration of the ammonium carbonate solution is preferably 20-45%; the mass concentration of the ammonium bicarbonate solution is preferably 20-45%; the mass concentration of the hydroxylamine solution is preferably 25-40%; the mass concentration of the sodium carbonate solution is preferably 20-30%; the mass concentration of the sodium bicarbonate solution is preferably 20-30%.

[0054] In the present invention, the volume ratio of the extract to the stripping agent is preferably (2-6): 1. As an embodiment, the volume ratio of the extract to the stripping agent may be specifically 2:1, 3:1, 4:1, 5:1 or 6:1.

[0055] In the present invention, the number of stages of the countercurrent stripping is preferably 1 to 3. As an embodiment, the number of stages of the countercurrent stripping can be specifically 1, 2 or 3.

[0056] In the present invention, the temperature of the countercurrent stripping is preferably 15 to 75° C. As an embodiment, the temperature of the countercurrent stripping may be specifically 15° C., 20° C., 25° C., 30° C., 35° C., 40° C., 45° C., 50° C., 55° C., 60° C., 65° C., 70° C. or 75° C.

[0057] In the present invention, the countercurrent stripping time is preferably 1 to 10 minutes.

[0058] The present invention controls various parameters during countercurrent stripping within the above ranges, which can further improve the extraction rate.

[0059] In the present invention, in the countercurrent stripping process, tungsten in the extract is stripped into the stripping agent to obtain a tungsten-containing solution.

[0060] In the present invention, the extractant obtained by the countercurrent stripping is preferably recycled.

[0061] In the present invention, the countercurrent extraction and countercurrent stripping are preferably carried out in a mixing and settling tank, an extraction tower or a centrifugal extractor. The present invention has no particular limitation on the type of the mixing and settling tank, the extraction tower or the centrifugal extractor, and any equipment familiar to those skilled in the art can be used.

[0062] The extraction process of the invention is simple, and only has two processes, extraction and back extraction. The extractant does not need to be pretreated by saponification, etc., thus reducing the use of acid and alkali reagents, having low requirements on equipment and good economy.

[0063] The technical solutions in the present invention will be described clearly and completely below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0064] Example 1

[0065] An extractant for extracting and separating tungsten and molybdenum, which is composed of 5% of di-secondary amine N,N-diphenylbutanediamine (CAS: 13170-61-1), 10% of monophosphorus oxide tricyclohexylphosphorus oxide (CAS: 13689-19-5) and the balance of diluent dichloromethane, by volume percentage;

[0066] The preparation method of the extractant for extracting and separating tungsten and molybdenum is as follows: N,N-diphenylbutanediamine, tricyclohexylphosphine and dichloromethane are mixed at room temperature and stirred evenly to obtain the extractant.

[0067] Application Example 1

[0068] (1) The extractant in Example 1 and a solution containing sodium tungstate and sodium molybdate (tungsten ion concentration of 19.0 g / L, molybdenum ion concentration of 1.3 g / L) are subjected to countercurrent extraction using a centrifugal extractor, the volume ratio of the extractant to the solution containing sodium tungstate and sodium molybdate is 1:1, the number of countercurrent extraction stages is 4, the temperature of the countercurrent extraction is 15° C., and the time of the countercurrent extraction is 9 min, to obtain an extract;

[0069] (2) The extract obtained in step (1) and the stripping agent (water) are subjected to countercurrent stripping using a centrifugal extractor, the volume ratio of the extract to the stripping agent is 2:1, the number of the countercurrent stripping is 1, the temperature of the countercurrent stripping is 20° C., and the time of the countercurrent stripping is 3 min, to obtain a tungsten-containing solution.

[0070] The tungsten-containing solution (sodium tungstate solution) obtained in Application Example 1 is directly measured by an ICP-MS instrument to determine the contents of sodium tungstate and sodium molybdate in the solution to obtain the purity of the tungsten-containing solution.

[0071] The extraction rate in Application Example 1 is 73%, and the purity of the tungsten-containing solution (sodium tungstate) is 80%.

[0072] Comparative Example 1

[0073] An extractant, calculated by volume percentage, consists of 15% of di-secondary amine N,N-diphenylbutanediamine (CAS: 13170-61-1) and the balance of diluent dichloromethane;

[0074] The preparation method of the extractant is as follows: N,N-diphenylbutanediamine and dichloromethane are mixed at room temperature and stirred evenly to obtain the extractant.

[0075] Comparative application example 1

[0076] The extractant of Example 1 in Application Example 1 was replaced by the extractant of Comparative Example 1, and other parameters were the same as those in Application Example 1 to obtain a tungsten-containing solution.

[0077] The extraction rate in Comparative Application Example 1 is 33%, and the purity of the tungsten-containing solution is 65%.

[0078] Comparative Example 2

[0079] An extractant, which, by volume percentage, consists of 15% of tricyclohexylphosphine oxide (CAS: 13689-19-5) and the remainder of diluent dichloromethane;

[0080] The preparation method of the extractant is as follows: tricyclohexylphosphine and dichloromethane are mixed at room temperature and stirred evenly to obtain the extractant.

[0081] Comparative Application Example 2

[0082] The extractant of Example 1 in Application Example 1 is replaced by the extractant of Comparative Example 2, and other parameters are the same as those in Application Example 1 to obtain a tungsten-containing solution.

[0083] The extraction rate in Comparative Application Example 2 is 23%, and the purity of the tungsten-containing solution is 66%.

[0084] Example 2

[0085] An extractant for extracting and separating tungsten and molybdenum, which is composed of 10% of di-secondary amine N,N-diphenylpropylenediamine (CAS: 104-69-8), 15% of monophosphorus oxide dipropyl cyclohexylphosphorus oxide (CAS: 73986-82-0) and the balance of diluent kerosene, by volume percentage;

[0086] The preparation method of the extractant for extracting and separating tungsten and molybdenum is as follows: N,N-diphenylpropylenediamine, dipropylcyclohexylphosphine and kerosene are mixed at room temperature, and stirred evenly to obtain the extractant.

[0087] Application Example 2

[0088] (1) The extractant in Example 2 and a solution containing sodium tungstate and sodium molybdate (tungsten ion concentration of 35.0 g / L, molybdenum ion concentration of 2.3 g / L) are subjected to countercurrent extraction using a centrifugal extractor, the volume ratio of the extractant to the solution containing sodium tungstate and sodium molybdate is 2:1, the number of countercurrent extraction stages is 5, the temperature of the countercurrent extraction is 20°C, and the time of the countercurrent extraction is 10 min, to obtain an extract;

[0089] (2) The extract obtained in step (1) and the stripping agent (ammonium carbonate solution, mass concentration of 25%) are subjected to countercurrent stripping by a centrifugal extractor, the volume ratio of the extract to the stripping agent is 3:1, the number of countercurrent stripping stages is 2, the temperature of the countercurrent stripping is 30° C., and the time of the countercurrent stripping is 2 min, to obtain a tungsten-containing solution.

[0090] The extraction rate in Application Example 2 is 87%, and the purity of the tungsten-containing solution is 85%.

[0091] Example 3

[0092] An extractant for extracting and separating tungsten and molybdenum, which is composed of 15% of di-secondary amine N,N-diphenylethylenediamine (CAS: 150-61-8), 20% of monophosphorus oxide methyl dicyclohexylphosphorus oxide (CAS: 42366-52-9) and the balance of diluent cyclohexane, by volume percentage;

[0093] The preparation method of the extractant for extracting and separating tungsten and molybdenum is as follows: N,N-diphenylethylenediamine, methyldicyclohexylphosphine and cyclohexane are mixed at room temperature and stirred evenly to obtain the extractant.

[0094] Application Example 3

[0095] (1) The extractant in Example 3 and a solution containing sodium tungstate and sodium molybdate (tungsten ion concentration of 69.0 g / L, molybdenum ion concentration of 1.1 g / L) are subjected to countercurrent extraction using a centrifugal extractor, the volume ratio of the extractant to the solution containing sodium tungstate and sodium molybdate is 3:1, the number of countercurrent extraction stages is 6, the temperature of the countercurrent extraction is 25° C., and the time of the countercurrent extraction is 9 min, to obtain an extract;

[0096] (2) The extract obtained in step (1) and the stripping agent (ammonia water, mass concentration of 30%) are subjected to countercurrent stripping by a centrifugal extractor, the volume ratio of the extract to the stripping agent is 3:1, the number of countercurrent stripping stages is 2, the temperature of the countercurrent stripping is 30° C., and the time of the countercurrent stripping is 1 min, to obtain a tungsten-containing solution.

[0097] The extraction rate in Application Example 3 is 91%, and the purity of the tungsten-containing solution is 97.5%.

[0098] Example 4

[0099] An extractant for extracting and separating tungsten and molybdenum, which is composed of 20% of di-secondary amine N,N-diphenylmethanediamine (CAS: 622-14-0), 25% of monophosphorus oxide diethylcyclohexylphosphorus oxide (CAS: 13689-18-4) and the balance of diluent toluene, by volume percentage;

[0100] The preparation method of the extractant for extracting and separating tungsten and molybdenum is as follows: N,N-diphenylmethanediamine, diethylcyclohexylphosphine and toluene are mixed at room temperature and stirred evenly to obtain the extractant.

[0101] Application Example 4

[0102] (1) The extractant in Example 4 and a solution containing sodium tungstate and sodium molybdate (tungsten ion concentration of 83.0 g / L, molybdenum ion concentration of 11.2 g / L) were subjected to countercurrent extraction using a centrifugal extractor, the volume ratio of the extractant to the solution containing sodium tungstate and sodium molybdate was 2:1, the number of countercurrent extraction stages was 4, the temperature of the countercurrent extraction was 29° C., and the time of the countercurrent extraction was 5 min, to obtain an extract;

[0103] (2) The extract obtained in step (1) and the stripping agent (hydroxylamine solution, mass concentration of 35%) are subjected to countercurrent stripping by a centrifugal extractor, the volume ratio of the extract to the stripping agent is 4:1, the number of the countercurrent stripping is 1, the temperature of the countercurrent stripping is 33° C., and the time of the countercurrent stripping is 1 min, to obtain a tungsten-containing solution.

[0104] The extraction rate in Application Example 4 is 88%, and the purity of the tungsten-containing solution is 90%.

[0105] Example 5

[0106] An extractant for extracting and separating tungsten and molybdenum, which is composed of 25% of di-secondary amine N,N-dibutylethylenediamine (CAS: 4013-95-0), 30% of monophosphorus oxide triphenylphosphine (CAS: 791-28-6) and the balance of diluent chloroform, by volume percentage;

[0107] The preparation method of the extractant for extracting and separating tungsten and molybdenum is as follows: N,N-dibutylethylenediamine, triphenylphosphine and chloroform are mixed at room temperature and stirred evenly to obtain the extractant.

[0108] Application Example 5

[0109] (1) The extractant in Example 5 and a solution containing sodium tungstate and sodium molybdate (tungsten ion concentration of 79.0 g / L, molybdenum ion concentration of 4.4 g / L) are subjected to countercurrent extraction using a centrifugal extractor, the volume ratio of the extractant to the solution containing sodium tungstate and sodium molybdate is 2:1, the number of countercurrent extraction stages is 4, the temperature of the countercurrent extraction is 60°C, and the time of the countercurrent extraction is 10 min, to obtain an extract;

[0110] (2) The extract obtained in step (1) is subjected to countercurrent stripping with a stripping agent (sodium hydroxide solution, with a mass concentration of 15%) using a centrifugal extractor, the volume ratio of the extract to the stripping agent is 5:1, the number of countercurrent stripping is 1, the temperature of the countercurrent stripping is 63° C., and the time of the countercurrent stripping is 1 min, to obtain a tungsten-containing solution.

[0111] The extraction rate in Application Example 5 is 91%, and the purity of the tungsten-containing solution is 90%.

[0112] Example 6

[0113] An extractant for extracting and separating tungsten and molybdenum, which is composed of 30% of di-secondary amine N,N-dipentylethylenediamine (CAS: 88619-07-2), 35% of monophosphorus oxide diisobutylcyclohexylphosphorus oxide (CAS: 52911-34-9) and the remainder of a diluent (cyclohexane and kerosene in a volume ratio of 2:1) by volume percentage;

[0114] The preparation method of the extractant for extracting and separating tungsten and molybdenum is as follows: N,N-dipentylethylenediamine, diisobutylcyclohexylphosphine, cyclohexane and kerosene are mixed at room temperature and stirred evenly to obtain the extractant.

[0115] Application Example 6

[0116] (1) The extractant in Example 6 and a solution containing sodium tungstate and sodium molybdate (tungsten ion concentration of 108.0 g / L, molybdenum ion concentration of 2.8 g / L) were subjected to countercurrent extraction using a centrifugal extractor, the volume ratio of the extractant to the solution containing sodium tungstate and sodium molybdate was 5:1, the number of countercurrent extraction stages was 3, the temperature of the countercurrent extraction was 34° C., and the time of the countercurrent extraction was 15 min, to obtain an extract;

[0117] (2) The extract obtained in step (1) and a stripping agent (potassium hydroxide solution, with a mass concentration of 20%) are subjected to countercurrent stripping using a centrifugal extractor, the volume ratio of the extract to the stripping agent is 4:1, the number of countercurrent stripping is 1, the temperature of the countercurrent stripping is 42° C., and the time of the countercurrent stripping is 5 min, to obtain a tungsten-containing solution.

[0118] The extraction rate in Application Example 6 is 89%, and the purity of the tungsten-containing solution is 94%.

[0119] Example 7

[0120] An extractant for extracting and separating tungsten and molybdenum, which is composed of 35% of di-secondary amine N,N-dihexylethylenediamine (CAS: 57413-98-6), 40% of monophosphorus oxide dibutylcyclopentylphosphorus oxide (CAS: 17636-47-4) and the remainder of a diluent (dichlorobenzene and chloroform in a volume ratio of 4:1) by volume percentage;

[0121] The preparation method of the extractant for extracting and separating tungsten and molybdenum is as follows: N,N-dihexylethylenediamine, dibutylcyclopentylphosphine, dichlorobenzene and chloroform are mixed at room temperature, and stirred evenly to obtain the extractant.

[0122] Application Example 7

[0123] (1) The extractant in Example 7 and a solution containing sodium tungstate and sodium molybdate (tungsten ion concentration of 274.0 g / L, molybdenum ion concentration of 22.0 g / L) were subjected to countercurrent extraction using a centrifugal extractor, the volume ratio of the extractant to the solution containing sodium tungstate and sodium molybdate was 1:1, the number of countercurrent extraction stages was 6, the temperature of the countercurrent extraction was 49° C., and the time of the countercurrent extraction was 11 min, to obtain an extract;

[0124] (2) The extract obtained in step (1) and the stripping agent (sodium bicarbonate solution, mass concentration of 20%) are subjected to countercurrent stripping by a centrifugal extractor, the volume ratio of the extract to the stripping agent is 5:1, the number of countercurrent stripping stages is 3, the temperature of the countercurrent stripping is 53° C., and the time of the countercurrent stripping is 3 min, to obtain a tungsten-containing solution.

[0125] The extraction rate in Application Example 7 is 82%, and the purity of the tungsten-containing solution is 91.5%.

[0126] Example 8

[0127] An extractant for extracting and separating tungsten and molybdenum, which is composed of 20% of di-secondary amine 1,2-bis(cyclohexylamino)ethane (CAS: 811-017-5), 45% of monophosphorus oxide tris(4-tert-butylcyclohexyl)phosphine (CAS: 786697-23-2) and the remainder of a diluent (cyclohexane and sulfonated kerosene in a volume ratio of 3:1) by volume percentage;

[0128] The preparation method of the extractant for extracting and separating tungsten and molybdenum is as follows: 1,2-bis(cyclohexylamino)ethane, tri(4-tert-butylcyclohexyl)phosphine, cyclohexane and sulfonated kerosene are mixed at room temperature and stirred evenly to obtain the extractant.

[0129] Application Example 8

[0130] (1) The extractant in Example 8 and a solution containing sodium tungstate and sodium molybdate (tungsten ion concentration of 174.0 g / L, molybdenum ion concentration of 15.6 g / L) were subjected to countercurrent extraction using a centrifugal extractor, the volume ratio of the extractant to the solution containing sodium tungstate and sodium molybdate was 2:1, the number of countercurrent extraction stages was 9, the temperature of the countercurrent extraction was 40° C., and the time of the countercurrent extraction was 35 min to obtain an extract;

[0131] (2) The extract obtained in step (1) and the stripping agent (ammonium carbonate solution, mass concentration of 25%) are subjected to countercurrent stripping by a centrifugal extractor, the volume ratio of the extract to the stripping agent is 3:1, the number of countercurrent stripping stages is 2, the temperature of the countercurrent stripping is 45° C., and the time of the countercurrent stripping is 10 min, to obtain a tungsten-containing solution.

[0132] The extraction rate in Application Example 8 is 97%, and the purity of the tungsten-containing solution is 99%.

[0133] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. An extractant for extracting and separating tungsten and molybdenum, which comprises 5-35% of di-secondary amine, 10-45% of monophosphorus oxide and the remainder of diluent, calculated by volume percentage.

2. The extractant according to claim 1, characterized in that The structural formula of the di-secondary amine is shown in Formula I: In the formula I, R 1 and R 2 Independently C1~C 25 Alkyl, C3~C 12 Cycloalkyl and C5~C 17 One of the aromatic groups; n is an integer from 1 to 20.

3. The extractant according to claim 1, characterized in that The structural formula of the monophosphorus oxide is shown in Formula II: In the formula II, R 3 , R 4 and R 5 Independently C1~C 40 Alkyl, C3~C 20 Cycloalkyl and C5~C 18 One of the aromatic groups.

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

5. Use of the extractant for extracting and separating tungsten and molybdenum according to any one of claims 1 to 4 in separating tungsten and molybdenum.

6. The use according to claim 5, characterized in that: The following steps are involved: (1) subjecting an extractant for extracting and separating tungsten and molybdenum to countercurrent extraction with a solution containing tungsten and molybdenum to obtain an extract; (2) The extract obtained in step (1) is subjected to countercurrent stripping with a stripping agent to obtain a tungsten-containing solution and an extracting agent.

7. The use according to claim 6, characterized in that: In the step (1), the volume ratio of the extractant for extracting and separating tungsten and molybdenum to the solution containing tungsten and molybdenum is (1-5):

1.

8. The use according to claim 6, characterized in that: In the step (1), the number of stages of countercurrent extraction is 1 to 15, and the temperature of countercurrent extraction is 10 to 70°C.

9. The use according to claim 6, characterized in that: The stripping agent in step (2) includes one or more of water, sodium hydroxide solution, potassium hydroxide solution, aqueous ammonia solution, ammonium carbonate solution, ammonium bicarbonate solution, hydroxylamine solution, sodium carbonate solution and sodium bicarbonate solution.

10. The use according to claim 6, characterized in that: The number of stages of countercurrent stripping in step (2) is 1 to 3, and the temperature of countercurrent stripping is 15 to 75°C.

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