A ligand, its preparation and use

Abstract

This invention discloses a ligand, its preparation method, and its application, belonging to the field of hydrometallurgical technology. The ligand provided by this invention has a main ring containing pyridine and pyrazole, and branched chains of C4, C8, and C6. 12 Straight-chain alkyl or branched C 12 Alkyl groups. When used in combination with other extractants, this ligand effectively improves the separation coefficient of nickel, cobalt, and other interfering metal ions during nickel-cobalt extraction, thereby increasing the extraction rate of nickel and cobalt, and also improving the separation coefficient between nickel and cobalt. This invention also provides a method for preparing the above-mentioned extractant and its applications.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of hydrometallurgy, in particular to a ligand, a preparation method and application thereof. BACKGROUND

[0002] Nickel and cobalt are important strategic resources, which have a wide range of applications in alloy industry, catalyst preparation, and new energy field. With the depletion of high-grade nickel and cobalt resources, the extraction and recovery of nickel and cobalt from secondary resources containing nickel and cobalt (such as waste catalysts, waste lithium-ion ternary batteries, waste hard alloys, and stainless steel containing nickel and cobalt) is an important measure for resource recycling and environmental protection. In addition, the "double carbon" policy requires industrial emissions, and the development of efficient short process extraction and purification of nickel and cobalt is increasingly important for the nickel and cobalt metallurgical industry.

[0003] The hydrometallurgical process of nickel and cobalt generally includes the following steps: leaching to make the metal enter the solution system, and then separating the target metal and impurities through crystallization, distillation, precipitation, solvent extraction, ion exchange, electrodialysis, membrane separation, etc. Among them, solvent extraction has a wide range of applications in metal ion separation in aqueous solution and heavy metal wastewater treatment due to its high extraction and separation efficiency, fast reaction speed, low process energy consumption, and easy realization of large scale, etc. such as nickel / cobalt separation, rare earth separation, and uranium element treatment in nuclear wastewater. At present, the organic phosphoric acid extractant P204 and P507 are mainly used in industrial extraction of nickel and cobalt, the former is mainly used for removing impurities in nickel and cobalt solution, and the latter is mainly used for nickel and cobalt separation. However, in the priority order of several commonly used phosphoric acid extractants for metal extraction, the priority of nickel and cobalt is relatively low, and it is very close to some metals, which has a serious co-extraction phenomenon, seriously affecting the product quality and causing complex separation process. Therefore, in a multi-metal solution system, pretreatment operation is needed to remove metals with priority before or close to nickel and cobalt, and these separation operations are complex and costly. In industry, methods such as precipitation are usually used to remove impurities with high content, but this process has problems such as high nickel loss and easy secondary pollution. Although multiple extractants can be used for multi-step extraction and separation, this method can cause mixing and mutual solubility between multiple extractants, which not only makes the extraction and separation effect worse, but also makes the extractant unable to be recycled. Therefore, changing the extraction priority order in the traditional extraction system and improving the selectivity of nickel and cobalt are the key to realizing efficient short process purification of nickel and cobalt.

[0004] The main factors affecting the extraction effect include extractants and ligands that have a synergistic effect with the extractants. Therefore, it is very important to provide extractants with better performance. SUMMARY

[0005] This invention aims to at least solve one of the technical problems existing in the prior art. To this end, this invention proposes a ligand that can effectively improve the separation coefficient of nickel, cobalt and other interfering metal ions during nickel-cobalt extraction, thereby increasing the extraction rate of nickel and cobalt, and also improving the separation coefficient between nickel and cobalt.

[0006] The present invention also provides a method for preparing the above-mentioned ligands.

[0007] The present invention also provides an organic phase comprising the above-described ligands.

[0008] The present invention also provides the application of the above-mentioned ligands in nickel / cobalt extraction.

[0009] According to an embodiment of a first aspect of the present invention, a ligand is provided having a structure as shown in Formula I:

[0010]

[0011] Where R is C4, C8, C 12 Straight-chain alkyl or branched C 12 alkyl.

[0012] The ligands according to embodiments of the present invention have at least the following beneficial effects:

[0013] The ligand designed in this invention is a bidentate pyridine ligand, which can coordinate in the inner layer of nickel and cobalt ions, displacing coordinated water molecules, and then forming a stable complex with the extractant (e.g., dinonylnaphthalenesulfonic acid anion), promoting the extraction of nickel and cobalt. At the same time, due to the limitation of R, the steric hindrance of the ligand when coordinating with metal ions is limited. When used to extract nickel and cobalt, it significantly improves the separation coefficient between nickel and cobalt and other metal ions, thereby improving the extraction efficiency of nickel and cobalt.

[0014] According to some embodiments of the present invention, in formula I, R is C 12 The ligand is a straight-chain alkyl group. As the carbon chain length of the straight-chain alkyl group increases, the steric hindrance of the ligand increases, thus enhancing its extraction inhibition effect on other impurity metal ions. Simultaneously, its hydrophobicity increases, improving the extraction rate of nickel and cobalt ions. If, with the same number of carbon chains, the number of branches increases, the steric hindrance effect will further increase, thereby reducing the extraction ratio of impurity metal ions and also decreasing the extraction rate of nickel and cobalt. Therefore, when R is C... 12 When using straight-chain alkyl groups, the separation efficiency between nickel, cobalt, and other impurity metal ions is superior, and the extraction rate of nickel and cobalt is also high. However, regardless of the group chosen for R, the ligand exhibits preferred extractability for nickel during extraction.

[0015] According to some embodiments of the present invention, the ligand is a pale yellow to yellow oily substance.

[0016] According to some embodiments of the present application, the branched C 12 Alkyl includes 2-butyl-octyl.

[0017] According to embodiments of the second aspect of the present application, there is provided a method for preparing the organic ligand, the method comprising subjecting 2-(1H-pyrazol-3-yl)pyridine and R-Br to a nucleophilic substitution reaction.

[0018] The method for preparing the organic ligand is simple and easy to implement, and facilitates large-scale use of the ligand in industry.

[0019] According to some embodiments of the present application, the 2-(1H-pyrazol-3-yl)pyridine (CAS: 75415-03-1) can be self-made or purchased commercially.

[0020] According to some embodiments of the present application, the self-made method comprises the following steps:

[0021] D1. Mixing a suspension of acetaldehyde, and sodium hydride, and tetrahydrofuran, and heating;

[0022] D2. Adding a tetrahydrofuran solution of 2-pyridinecarboxylic acid ethyl ester (CAS: 2524-52-9) dropwise to the mixture obtained in step D1, and continuing the reaction;

[0023] D3. Cooling the mixture obtained in step D2, and adjusting the pH;

[0024] D4. Extracting the mixture obtained in step D3 with diethyl ether, washing the organic phase obtained with brine, and drying and concentrating the organic phase; to obtain 3-oxo-3-(pyridin-2-yl)propanol;

[0025] D5. Reacting the mixture obtained in step D4 with hydrazine hydrate, and removing the solvent.

[0026] According to some embodiments of the present application, in step D1, the mixing method is stirring, and the time length is 10-30 min. In actual industrial production, the mixing method and time length are not strictly limited, as long as mass transfer can be sufficiently achieved.

[0027] According to some embodiments of the present application, in step D1, the target temperature of the heating is 50-70°C, for example, specifically about 60°C.

[0028] According to some embodiments of the present application, in step D2, the temperature of the continued reaction is the target temperature of the heating in step D1.

[0029] According to some embodiments of the present application, in step D2, the time length of the continued reaction is 10-30 min. For example, specifically about 20 min.

[0030] According to some embodiments of the present application, in step D3, the temperature of the mixture is cooled to a temperature of -5 to 5°C, for example, specifically about 0°C.

[0031] According to some embodiments of the present application, in step D3, the pH is adjusted to a range of 8 to 9.

[0032] According to some embodiments of the present application, in step D4, the drying method is drying with anhydrous magnesium sulfate.

[0033] According to some embodiments of the present application, the time between the end of step D4 and the beginning of step D5 is ≤ 10 min.

[0034] According to some embodiments of the present application, in step D5, the reaction time is 80 to 100 min, for example, specifically about 90 min.

[0035] According to some embodiments of the present application, in step D5, the desolvation method is distillation under reduced pressure.

[0036] According to some embodiments of the present application, the nucleophilic substitution reaction comprises the following steps:

[0037] S1. Mixing the 2-(1H-pyrazol-3-yl)pyridine, sodium hydroxide and toluene;

[0038] S2. Mixing R-Br and the mixture obtained in step S1 and refluxing.

[0039] According to some embodiments of the present application, in step S1, the mixing method is stirring. The mixing temperature is 15 to 40°C, for example, specifically about 25°C. The mixing time is 30 to 90 min, for example, specifically about 60 min.

[0040] According to some embodiments of the present application, in step S1, the molar ratio of 2-(1H-pyrazol-3-yl)pyridine to sodium hydroxide is 1:10 to 15, for example, specifically about 1:12.

[0041] According to some embodiments of the present application, in step S1, the molar ratio of 2-(1H-pyrazol-3-yl)pyridine to toluene is 1:35 to 45, for example, specifically about 1:41.

[0042] According to some embodiments of the present application, in step S1, the sodium hydroxide is added in the form of a solution thereof. The concentration of the solution is 35 to 45%, for example, specifically about 40%.

[0043] According to some embodiments of the present application, the amount of R-Br in step S2 and the amount of 2-(1H-pyrazol-3-yl)pyridine in step S1 is 5-15% excess over the stoichiometric ratio. For example, it can be specifically 10% excess. The excess is calculated based on the stoichiometric ratio, for example, 1 mol is needed for the stoichiometric acid, and the actual amount added is 1.05-1.1 mol.

[0044] According to some embodiments of the present application, in step S2, the mixing is performed by slowly adding the R-Br to the mixture obtained in step S1. This addition method can prevent safety problems caused by uncontrollable violent reactions.

[0045] According to some embodiments of the present application, the slow addition refers to an addition time of ≤2 min. For example, it can be specifically about 1 min.

[0046] According to some embodiments of the present application, in step S2, the refluxing time is 70-80 h. For example, it can be specifically about 72 h.

[0047] According to some embodiments of the present application, the nucleophilic substitution reaction further comprises purifying the ligand in step S2.

[0048] According to some embodiments of the present application, the purification method is silica gel column chromatography, toluene is used as the eluent to remove impurities in the sample, and ethyl acetate is used as the eluent to flush the product in the column. Finally, the eluent is removed by high vacuum.

[0049] According to some embodiments of the third aspect of the present application, an organic phase is provided, and the raw materials of the organic phase include the ligand, the extractant and the diluent; the extractant includes dinonyl naphthalene sulfonic acid.

[0050] The organic phase according to the embodiments of the present application has at least the following beneficial effects:

[0051] Due to the intermolecular interaction between the bidentate pyridine ligand and the extractant such as dinonyl naphthalene sulfonic acid, the molecular association formed by the two inhibits the coordination of the ligand with impurity ions, thereby realizing the preferential extraction of nickel and cobalt; further, since the extraction pH50 of nickel and cobalt is different, the step-by-step separation of nickel and cobalt can be realized by changing the pH and the formula of the organic phase.

[0052] The organic phase provided by the present application is easy to separate from the aqueous phase and is not easy to emulsify.

[0053] According to some embodiments of the present application, in the organic phase, the molar ratio of the extractant to the ligand is 0.25-4:1. For example, it can be specifically about 1:1, 1.5:1 or 2:3.

[0054] According to some embodiments of the present application, the concentration of the extractant in the organic phase is 0.01-0.5 mol / L. For example, it can be about 0.02 mol / L, 0.03 mol / L, 0.04 mol / L, 0.05 mol / L, 0.06 mol / L, 0.08 mol / L or 0.1 mol / L.

[0055] According to some embodiments of the present application, the diluent in the organic phase comprises toluene.

[0056] According to some embodiments of the fourth aspect of the present application, the organic phase is used in nickel / cobalt extraction.

[0057] Since the application adopts all the technical solutions of the ligand of the above embodiments, it has at least all the beneficial effects brought by the technical solutions of the above embodiments. Specifically, in the process of nickel / cobalt extraction, the distribution coefficient between nickel / cobalt, especially nickel, and other impurity metal ions can be improved, and the extraction efficiency of nickel / cobalt, especially nickel, can be improved; in the nickel / cobalt extraction of the present application, a strict and lengthy impurity removal process is not required, thereby significantly reducing the difficulty and time consumption of nickel / cobalt extraction.

[0058] According to some embodiments of the present application, the nickel / cobalt extraction comprises performing a first extraction on the aqueous solution to be extracted using the organic phase.

[0059] The aqueous solution to be extracted comprises at least one of nickel ions and cobalt ions.

[0060] In the application provided by the present application, a specific organic phase is used to directly extract and separate nickel and cobalt (including separating nickel / cobalt and other impurity ions, and separating nickel / cobalt), and the separation selectivity is high, and the extractant does not need to be saponified, and the nickel extraction rate is still high at pH<2.

[0061] According to some embodiments of the present application, the pH of the aqueous solution to be extracted is 1.5-3.0. For example, it can be about 2. Generally, the pH of an aqueous solution containing a large amount of metal ions is low, and therefore, if the pH of the incoming aqueous solution in actual production is not within the above range, pH adjustment is required, for example, a certain amount of sodium hydroxide can be added.

[0062] According to some embodiments of the present application, the O / A ratio of the first extraction is 0.25-4:1. For example, it can be about 0.5:1, 1:1, 2:1 or 1:3.

[0063] According to some embodiments of the present application, the first extraction is single-stage extraction.

[0064] According to some embodiments of the present application, the first extraction is performed for 25-35 minutes, for example, specifically, about 30 minutes. The time period is the time period of mixing. The mixing means includes at least one of shaking and stirring. When the mixing means is stirring, the stirring speed is 200-500 rpm, for example, specifically, about 300 rpm.

[0065] According to some embodiments of the present application, the first extraction is performed at a temperature of 15-40°C, for example, specifically, about 25°C. That is, the ambient temperature can be used, and no additional temperature adjustment is needed.

[0066] According to some embodiments of the present application, the nickel / cobalt extraction further includes stripping the primary loaded organic phase obtained from the first extraction.

[0067] According to some embodiments of the present application, in the stripping of the primary loaded organic phase, the aqueous phase used is an acid aqueous solution.

[0068] According to some embodiments of the present application, the acid aqueous solution has a H + The concentration is between 0.2-4 mol / L. For example, specifically, 0.5 mol / L, 1 mol / L or 2 mol / L.

[0069] According to some embodiments of the present application, the solute of the acid aqueous solution includes sulfuric acid.

[0070] According to some embodiments of the present application, in the stripping of the primary loaded organic phase, the O / A ratio is 1:1-5; for example, specifically, about 1:4.

[0071] According to some embodiments of the present application, in the stripping of the primary loaded organic phase, the time period is 5-20 minutes. For example, specifically, about 10 minutes. Within the above time period, the organic phase and the aqueous phase are mixed, and the mixing means includes at least one of shaking and stirring. When the mixing means is stirring, the stirring speed is 200-500 rpm, for example, specifically, about 300 rpm.

[0072] According to some embodiments of the present application, in the stripping of the primary loaded organic phase, the temperature is 15-40°C. For example, specifically, about 25°C.

[0073] According to some embodiments of the present application, the nickel / cobalt extraction further includes washing the blank organic phase obtained from the stripping to obtain a regenerated organic phase.

[0074] According to some embodiments of the present application, the nickel / cobalt extraction includes the following steps:

[0075] B1. using an organic phase to extract the aqueous solution to obtain a raffinate phase and a primary loaded organic phase;

[0076] B2. using an acid aqueous solution to back extract the primary loaded organic phase to obtain a nickel-rich aqueous phase and a blank organic phase;

[0077] B3. washing the blank organic phase obtained in step B2 to obtain a regenerated organic phase.

[0078] According to some embodiments of the present application, the nickel-rich aqueous phase can also include cobalt. Specifically, the proportion of cobalt included is determined by the O / A ratio of the first extraction in step B1 and the composition of the organic phase. In other words, the organic phase has strong affinity to both nickel ions and cobalt ions, so if the organic phase is excessive, it can extract both nickel and cobalt in the aqueous solution into the primary loaded organic phase and then into the nickel-rich aqueous phase; however, the organic phase has higher affinity to nickel ions than to cobalt ions, so by controlling the amount of the organic phase, most of the cobalt ions can be left in the raffinate phase, and the content of metal ions other than nickel in the nickel-rich aqueous phase is very low.

[0079] According to some embodiments of the present application, when the aqueous solution to be extracted includes nickel ions and cobalt ions, the nickel / cobalt extraction further includes using the organic phase to extract the raffinate phase obtained in the first extraction for a second time;

[0080] The organic phases used in the first extraction and the second extraction can be the same or different.

[0081] According to some embodiments of the present application, the pH of the raffinate phase is 1.5-3.0. For example, it can be about 2. If the pH of the raffinate phase changes, it needs to be adjusted, for example, sulfuric acid or sodium hydroxide can be used as a pH adjuster.

[0082] According to some embodiments of the present application, the O / A ratio of the second extraction is 0.25-4:1. For example, it can be about 0.5:1, 1:1, 2:1 or 1:3.

[0083] Specifically, the conditions of the second extraction and the first extraction can be the same or different. If it is only to separate nickel / cobalt and other impurity ions, the same conditions can be used for extraction. If it is to improve the separation efficiency between nickel and cobalt, the composition of the organic phase and the aqueous phase needs to be fine-tuned according to the pH50 of nickel and cobalt.

[0084] According to some embodiments of the present application, the nickel / cobalt extraction further includes back extracting the secondary loaded organic phase obtained in the second extraction. The aqueous phase used is an acid aqueous solution; further, the H +The concentration is between 0.2-4 mol / L; further, in the stripping, the O / A ratio is 1:1-5; for example, it can be about 1:4.

[0085] The stripping of the primary loaded organic phase and the secondary loaded organic phase can be the same or different.

[0086] According to some embodiments of the present application, the aqueous solution to be extracted further comprises at least one of Mn 2+ , Mg 2+ , Al 3+ , Ca 2+ , Zn 2+ and Fe 3+ . In the organic phase used in the present application, specific ligands and extractants are used, and after the combination and cooperation of the two, even if there are a large number of metal ions similar to nickel and cobalt in the solution, nickel and cobalt can be extracted by simple extraction, without the need for complex impurity removal.

[0087] According to some embodiments of the present application, when the aqueous solution to be extracted contains both nickel and cobalt, the step of nickel / cobalt extraction is:

[0088] B1. First extraction is performed on the aqueous solution to be extracted using an organic phase, to obtain a raffinate phase and a primary loaded organic phase;

[0089] B2. Stripping is performed on the primary loaded organic phase using an aqueous acid solution; a nickel-rich aqueous phase and a blank organic phase are obtained;

[0090] B3. The blank organic phase obtained in step B2 is washed to obtain a regenerated organic phase.

[0091] Second extraction is performed on the raffinate phase using an organic phase, to obtain an impurity aqueous phase and a secondary loaded organic phase;

[0092] B4. Stripping is performed on the secondary loaded organic phase using an aqueous acid solution; a cobalt-rich aqueous phase and a blank organic phase are obtained.

[0093] B5. The blank organic phase obtained in step B4 is washed to obtain a regenerated organic phase.

[0094] Thus, the regenerated organic phase can be returned to step B1 and step B3 for first extraction or second extraction, and the raw material is recycled, which significantly improves the raw material cost in the application and reduces the negative impact of waste raw materials on the environment.

[0095] Through two simple extractions, not only can nickel, cobalt and other impurity metal ions be separated, but also nickel and cobalt can be simply separated, and compared with traditional extraction, the process and cost of nickel / cobalt extraction are significantly reduced. If separation of nickel and cobalt is not required, only first extraction is needed, and second extraction is not required.

[0096] The order of steps B1-B5 is only for convenience of description, and is not strictly limited, as long as the actual feasible logic is met, for example, the first extraction should be earlier than the second extraction; each extraction should be earlier than the corresponding stripping; and each stripping should be earlier than the washing of the blank organic phase. Overall, the order of steps can be adjusted according to the equipment conditions and site conditions in actual production.

[0097] According to some embodiments of the present application, the washing in steps B3 and B5 refers to washing with pure water. Therefore, the organic phase containing the ligand has a simple rebirth method and is easy to operate, which further reduces the difficulty of nickel / cobalt extraction.

[0098] According to some embodiments of the present application, in step B3, the impurity aqueous phase contains almost all impurity ions except nickel and cobalt.

[0099] Overall, the present application provides an application of the organic phase containing the ligand in the extraction of nickel / cobalt, specifically a high-efficiency and short-process extraction method for selectively extracting and purifying nickel and cobalt from a sulfuric acid medium acidic polymetallic solution. In particular, the effective separation of nickel and cobalt ions from impurity metal ions can be directly realized without solution pretreatment and saponification of the organic phase. The present application has the advantages of simple operation, high extraction efficiency, good separation effect, low operation cost, recyclable organic phase, and easy industrialization.

[0100] Unless otherwise specified, the meaning of "about" in the present application actually represents an allowable error within ±2%, for example, about 100 actually means 100±2%*100.

[0101] Unless otherwise specified, "between" in the present application includes the numbers, for example, "between 2-3" includes the end values 2 and 3.

[0102] Other features and advantages of the present application will be set forth in the description that follows, and in part will become apparent to those skilled in the art from the description, or can be learned by practice of the application. BRIEF DESCRIPTION OF DRAWINGS

[0103] The above and / or additional aspects and advantages of the present application will become apparent and be readily understood from the description that follows, including the appended drawings, in which:

[0104] Figure 1 is the nuclear magnetic hydrogen spectrum of the ligand obtained in Example 2 of the present application;

[0105] Figure 2 is the nuclear magnetic carbon spectrum of the ligand obtained in Example 2 of the present application;

[0106] Figure 3is the attenuated total reflection infrared spectrum of the ligand obtained in Example 3 of the present application.

[0107] Figure 4 is a flow diagram of the extraction in the application example of the present application. DETAILED DESCRIPTION

[0108] The concept and the technical effects of the present application will be described in detail below in combination with the embodiments, so as to fully understand the purpose, features and effects of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments of the present application, other embodiments obtained by those skilled in the art without creative labor are within the protection scope of the present application.

[0109] In the description of the present application, the description of the terms "one embodiment", "some embodiments", "exemplary embodiment", "example", "specific example" or "some examples" means that the specific features, structures, materials or characteristics described in combination with the embodiment or example are contained in at least one embodiment or example of the present application. In the present specification, the exemplary description of the above terms does not necessarily mean the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0110] If no special description, the distribution ratio D, separation coefficient β, extraction rate E x (%) and stripping rate E s (%) are calculated according to formula (1)-(5) respectively:

[0111] D = C MO / C MA (1);

[0112] β Ni / M =D Ni / D M (2);

[0113] β Co / M =D Co / D M (3);

[0114] E x =C M0 -C MA / C M0 (4);

[0115] E s =C Ms V Ms / C MO V O (5);

[0116] wherein C MO , C MA respectively represent the concentration of metal ion M in the loaded organic phase and the raffinate phase (mol / L); β Ni / M , β Co / M respectively represent the separation coefficient of Ni, Co and impurity M; D Ni , D Co , D M respectively represent the distribution ratio of Ni, Co and impurity M; C M0 , in formula (4) represents the initial concentration of metal ion M in the aqueous solution to be extracted (mol / L); C Ms , in formula (5) represents the concentration of metal ion in the stripping solution (mol / L); V s , V O respectively represent the volume of the stripping solution and the loaded organic phase.

[0117] Example 1

[0118] In this example, a ligand with R being a C4 linear alkyl group was prepared, and the specific steps were as follows:

[0119] S1. 2-(1H-pyrazol-3-yl)pyridine was stirred and mixed with a sodium hydroxide solution in toluene at room temperature (about 25°C) for 1 h; the molar ratio of 2-(1H-pyrazol-3-yl)pyridine, sodium hydroxide and toluene was 1:12:41; the mass of 2-(1H-pyrazol-3-yl)pyridine was 1 g; the concentration of the sodium hydroxide solution used in this example was 40%.

[0120] S2. A slight excess (10% excess over the stoichiometric amount required) of bromobutane (CAS: 109-65-9) was slowly added (added at a uniform speed within 1-2 min) to the mixture obtained in step S1, and refluxed for 72 h;

[0121] S3. Impurities in the sample were removed by silica gel column chromatography with toluene as the eluent, and the product was eluted with ethyl acetate; finally, the eluent was removed by high vacuum to obtain a bidentate ligand in the form of a light yellow oil.

[0122] Examples 2-4 each prepared a ligand with R being a C8 linear alkyl group, a C 12 linear alkyl group, and a C 12 branched alkyl group, and the difference between the specific and Example 1 was as follows:

[0123] In Example 2, bromobutane in step S2 was replaced with an equivalent amount of bromooctane (CAS: 111-83-1);

[0124] In Example 3, the bromobutane in Step S2 is replaced by an equal amount of bromododecane (CAS: 112-29-8);

[0125] In Example 4, the bromobutane in Step S2 is replaced by an equal amount of 2-butyl-1-bromooctane (CAS: 85531-02-8).

[0126] Test Example 1

[0127] This example tests the infrared and nuclear magnetic results of the ligands obtained in Examples 1-4 to prove that the corresponding ligands are indeed synthesized according to the present application. The results of the ligand obtained in Example 2 are shown below. Figures 1-3 Since the results are similar, the results of Example 1 and Examples 3-4 are not described in detail here.

[0128] Example 5

[0129] This example provides a set of organic phases, the specific compositions of which are shown in Table 1.

[0130] Table 1 Composition of the organic phase in Example 5

[0131]

[0132] Application Example 1

[0133] This example uses the C8 organic phase obtained in Example 5 (referred to as Group C in this example), a 0.05 mol / L solution of dinonylnaphthalene sulfonic acid in toluene (referred to as Group A in this example), and a 0.05 mol / L solution of the ligand obtained in Example 2 in toluene (referred to as Group B in this example) as the organic phase to perform one extraction on an aqueous solution to be extracted, and calculates the extraction rates of nickel, cobalt and impurity ions, as well as the distribution ratio and distribution coefficient of nickel, cobalt and other impurity ions. Specifically:

[0134] The composition of the aqueous solution to be extracted is: Ni 2+ 0.508 g / L, Fe 3+ 0.410 g / L, Al 3+ 0.078 g / L, Ca 2+ 0.056 g / L, Co 2+ 0.053 g / L, Zn 2+ 0.034 g / L, Mg 2+ 4.086 g / L, and the pH value of the feed solution is 2.53; it is a sulfuric acid leaching solution of laterite nickel ore.

[0135] The extraction is single-stage extraction, the O / A ratio is 1:1, and the temperature is 25°C; the mixing time is 30 min, and the mixing method is stirring at a speed of 300 rpm.

[0136] In this example, the extraction rates of the metal ions are shown in Table 2, and the distribution ratio and separation coefficient are shown in Table 3.

[0137] Table 2 extraction rate of metal ions in application example 1

[0138] Group A B C Ni extraction rate (%) 47.9 14.3 89.8 Fe extraction rate (%) 62.6 16.9 6.83 Al extraction rate (%) 78.2 12.4 3.85 Ca extraction rate (%) 61.4 18.2 7.14 Co extraction rate (%) 50.0 14.1 20.8 Zn extraction rate (%) 50.1 14.5 8.57 Mg extraction rate (%) 43.6 13.7 1.76

[0139] Table 3 separation coefficient between nickel, cobalt and other metal ions in application example

[0140]

[0141] In Table 3, the subscripts 1-3 of the distribution ratio and the separation coefficient correspond to groups A-C, respectively.

[0142] According to the above results, it can be seen that the extraction of nickel using dinonylnaphthalene sulfonic acid or pyridylpyrazole bidentate ligand (Example 2) alone shows poor selectivity, wherein the extraction ability of dinonylnaphthalene sulfonic acid alone is stronger, and the priority order is Al>Fe>Ca>Zn>Co>Ni>Mg, and the extraction ability of pyridylpyrazole bidentate ligand is weaker, and the extraction ability of the contained metals is relatively close; however, when the mixed system of the two is used for extracting nickel, the extraction rate of Ni is close to 90%, while the extraction rates of Fe, Al, Ca, Zn and Mg impurity metals are lower than 10%, and nickel and cobalt are slightly co-extracted. Thus, it is shown that in the organic phase provided by the present application, the extraction agent and the ligand have synergy, which collectively improves the extraction rate of nickel and inhibits the extraction of other metals.

[0143] It can also be found from the results that the separation coefficient of Ni and other metal impurities is ≥90, and even close to 500, and the separation coefficient between Ni and Co is above 30. Therefore, the organic phase provided by the present application has obvious synergistic extraction effect on nickel, and the single-stage extraction process can better separate Ni from other metals, including the separation between nickel and cobalt.

[0144] Application Example 2

[0145] In this example, the four organic phases obtained in Example 5 were used for single-stage extraction of laterite sulfuric acid leaching solution (same as in application example 1) to verify the extraction effect of ligand branched type on metal ions in the aqueous solution to be extracted. The extraction conditions were the same as in application example 1. The results are shown in Table 4.

[0146] Table 4 performance of organic phase containing different ligands

[0147] Organic phase number [C4] [C8] C 12 ]]> branched C 12 ]] Ni extraction rate (%) 82.32 89.8 91.54 87.36 Fe extraction rate (%) 7.21 6.83 6.07 6.23 Al extraction rate (%) 4.44 3.85 3.69 3.90 Ca extraction rate (%) 9.93 7.14 7.05 7.85 Co extraction rate (%) 25.58 20.8 19.87 21.54 Zn extraction rate (%) 10.70 8.57 6.48 7.39 Mg extraction rate (%) 2.62 1.76 1.65 1.81

[0148] The results showed that with increasing alkyl chain length, the steric hindrance further enhanced the ligand's ability to suppress impurities. Simultaneously, the increased hydrophobicity of the L ligand promoted Ni extraction. However, if the alkyl chain had large branched structures, the steric hindrance effect would be further increased, leading to a decrease in the overall metal extraction rate, but without altering the preferential extraction of Ni. Therefore, the design of the ligand structure can adjust the steric hindrance and alkyl chain structure of the ligand molecule to promote the system's suppression of impurities and enhance nickel extraction.

[0149] Application Example 3

[0150] This example uses the C8 organic-based laterite sulfuric acid leachate obtained in Example 5 (same as Application Example 1) for single-stage extraction to verify the effect of the O / A ratio on the extraction efficiency. The extraction conditions, except for the O / A ratio, are the same as in Application Example 1. The correspondence between the results and the O / A ratio is shown in Table 5.

[0151] Table 5. Effect of O / A ratio on extraction efficiency

[0152]

[0153]

[0154] The results showed that the extraction rates of nickel and cobalt decreased significantly with decreasing O / A ratio, while the extraction rates of other impurities did not change much. However, the extraction rates of nickel and cobalt remained higher than those of other impurities. This may be because, when the aqueous solution and organic phase are matched in a specific ratio, an O / A ratio of approximately 1:1 precisely reaches the saturation loading of the organic phase relative to nickel. Reducing the amount of organic phase will decrease the extraction rates of nickel and cobalt. Considering the separation factors of nickel and cobalt, the system achieves the best separation effect for each metal when O / A = 1:1, with a nickel extraction rate close to 90%, a cobalt extraction rate around 20%, and other impurity metals around 10%. Single-stage extraction can achieve preliminary separation of nickel, cobalt, and other metallic impurities. However, this ratio is affected by the composition of the aqueous solution and the organic phase; if these conditions change, the ratio may also change.

[0155] Application Example 4

[0156] In this example, the C8 organic phase obtained in Example 5 (referred to as Group C in this example) and a toluene solution of 0.05 mol / L dinonylnaphthalenesulfonic acid (referred to as Group A in this example) were used as the organic phases to perform single-stage extraction on the sulfuric acid leaching solution of lateritic nickel ore (with the same composition as in Application Example 1, and pH as shown in Table 6) to verify the effect of the pH of the aqueous solution to be extracted on the extraction rate. The specific extraction conditions were the same as in Application Example 1. The results are shown in Table 6.

[0157] Table 6 Effect of pH on extraction rate

[0158]

[0159] The above results show that the single dinonyl naphthalene sulfonic acid extractant cannot achieve selective separation of nickel under any pH condition. The organic phase provided by the present application can still extract 46% of nickel under the condition that the initial pH of the aqueous solution to be extracted is 1.67, and the co-extraction rate of the remaining impurities is low. When the initial pH of the aqueous solution to be extracted is 2.01, the extraction efficiency of nickel is about 65%, and when the initial pH of the aqueous solution to be extracted is 3.00, the extraction rate of nickel exceeds 90%, and the extraction of other impurity ions does not significantly increase; this conforms to the extraction mechanism of cation exchange of acidic extractant; thus, it is expected to achieve selective extraction of nickel in the pH range of 1.5-2.0.

[0160] Application Example 5

[0161] This example back extracts the loaded organic phase obtained in group C of application example 1, and verifies the influence of the composition of the aqueous phase used for back extraction on the back extraction efficiency, specifically:

[0162] The O / A ratio of back extraction is 1:1, the mixing time is 30 min, the stirring speed is 300 r / min, and the temperature is 25°C.

[0163] The aqueous phase used for back extraction is a sulfuric acid aqueous solution, and the sulfuric acid concentration and extraction effect are shown in Table 7.

[0164] Table 7 Influence of concentration of aqueous phase used for back extraction on back extraction efficiency

[0165] Sulfuric acid concentration (mol / L) 0.1 0.25 0.5 1.0 2.0 Co stripping rate 61.36 64.68 72.60 75.39 78.86 Ni stripping rate 25.68 59.85 81.26 86.79 97.86

[0166] The results show that with the increase of acidity, the back extraction efficiency of nickel and cobalt increases to a certain extent. Considering the cost and the effect of nickel-cobalt separation, 2 mol / L of sulfuric acid aqueous solution is a relatively appropriate concentration choice. However, the acid concentration of the aqueous phase used for back extraction can also be adjusted according to actual conditions.

[0167] Application Example 6

[0168] This example performs a second extraction on the raffinate phase obtained in group C of application example 1, and back extracts the secondary loaded organic phase obtained, wherein:

[0169] The composition of the raffinate phase is: Ni 2+ 0.052 g / L, Fe 3+ 0.382 g / L, Al 3+ 0.075 g / L, Ca 2+ 0.052 g / L, Co 2+ 0.042 g / L, Zn 2+ 0.031 g / L, Mg 2+ 4.014 g / L, and the pH of the feed solution is adjusted to 2.50.

[0170] Extraction: C8 group organic phase in Example 5 was used, O / A ratio was 1:1, mixing time was 30 min, stirring rate was 300 r / min, and temperature was 25℃.

[0171] Stripping: aqueous phase was 2 mol / L sulfuric acid, O / A ratio was 1:1, mixing time was 10 min, stirring rate was 300 r / min, and temperature was 25℃, and single-stage stripping was performed.

[0172] The flowchart of the combination of the extraction process of Group C in Application Example 1, the stripping process of Application Example 5, and the process of this example is shown in Figure 4 The results of the extraction and stripping of this example are shown in Table 8.

[0173] Table 8 Results of the second extraction and stripping

[0174]

[0175] According to the above results, in the cobalt extraction, the extraction rate of the remaining nickel in the raffinate is close to 100%, and the extraction rate of cobalt can reach 65%; although nickel is still preferentially extracted, the nickel content in the raffinate is low, and the extraction rate of other impurity metals is all below 10%, so the extractant system can preferentially extract nickel and further extract and separate cobalt. That is, the process provided in the application can realize the preliminary separation of nickel and cobalt, and realize the efficient separation of nickel / cobalt and other impurities. The extraction process is very short, which can reduce the capital cost and time cost of nickel and cobalt hydrometallurgy. Figure 4 According to the above results, in the cobalt extraction, the extraction rate of the remaining nickel in the raffinate is close to 100%, and the extraction rate of cobalt can reach 65%; although nickel is still preferentially extracted, the nickel content in the raffinate is low, and the extraction rate of other impurity metals is all below 10%, so the extractant system can preferentially extract nickel and further extract and separate cobalt. That is, the process provided in the application can realize the preliminary separation of nickel and cobalt, and realize the efficient separation of nickel / cobalt and other impurities. The extraction process is very short, which can reduce the capital cost and time cost of nickel and cobalt hydrometallurgy.

[0176] Application Example 7

[0177] This example verifies the influence of the molar ratio of the ligand and the extractant in the organic phase on the extraction effect, specifically:

[0178] Aqueous solution to be extracted: waste ternary lithium ion battery sulfuric acid leaching solution, containing Ni 2+ 0.696 g / L, Co 2+ 0.309 g / L, Mn 2+ 0.311 g / L, Mg 2+ 0.022 g / L, Zn 2+ 0.091 g / L, Fe 3+ 0.108 g / L, Al 3+ 0.015 g / L, and pH is 2.53.

[0179] Organic phase: C8, C8-1, C8-2, C8-3, C8-4 in Example 5, and 0.1 mol / L of dinonyl naphthalene sulfonic acid toluene solution, and 0.1 mol / L of the ligand obtained in Example 2 toluene solution.

[0180] The extraction was carried out under the same conditions as in Application Example 1. The test results are shown in Table 9.

[0181] Table 9 Influence of organic phase composition on extraction effect

[0182] Organic phase number Dinonylnaphthalene sulfonic acid [C8-1] [C8-2] [C8] [C8-3] [C8-4] Ligand Ni extraction rate (%) 47.87 58.84 80.87 82.47 67.11 45.61 14.28 Co extraction rate (%) 49.99 38.13 31.14 16.05 15.68 12.00 14.07 Mn extraction rate (%) 52.24 35.35 13.40 4.70 4.50 5.66 13.52 Mg extraction rate (%) 43.62 28.17 10.48 4.50 4.38 5.58 13.67 Zn extraction rate (%) 50.15 36.35 20.24 5.42 5.58 6.02 14.48 Fe extraction rate (%) 62.58 43.44 17.92 6.35 6.28 10.98 16.90 Al extraction rate (%) 78.21 56.31 17.12 5.18 4.73 6.41 12.35

[0183] The results of this example are similar to those obtained in Application Example 1: no metal separation performance for the extractant and the ligand alone, but when the molar ratio of the extractant / ligand is between 1 and 1.5:1, the extraction efficiency of nickel is significantly improved, and the separation ability from other metals is increased, indicating that the organic phase provided by the application has a preferential extraction and separation ability for nickel in the sulfuric acid leaching solution of the waste ternary lithium ion battery.

[0184] Application Example 8

[0185] This example verifies the influence of the concentration of the extractant and the ligand in the organic phase on the extraction effect, specifically:

[0186] The aqueous solution to be extracted: sulfuric acid leaching solution of waste hydrogenation catalyst, containing Ni 2+ 0.562 g / L, Al 3+ 9.37 g / L, Fe 3+ 0.056 g / L, and the pH of the feed solution was 2.97.

[0187] Organic phase: the molar ratio of dinonylnaphthalene sulfonic acid and the ligand obtained in Example 2 was 1:1; the total concentration of dinonylnaphthalene sulfonic acid and the ligand was 0.0.04 mol / L, 0.08 mol / L, 0.12 mol / L, 0.16 mol / L, and 0.20 mol / L, respectively.

[0188] The specific conditions of the extraction were the same as in Application Example 1. The test results are shown in Table 10.

[0189] Table 10 Influence of organic phase concentration on extraction effect

[0190]

[0191]

[0192] The results show that dinonylnaphthalene sulfonic acid and the ligand provided by the application have strong preferential extraction ability for nickel ions in the sulfuric acid leaching solution of the waste hydrogenation catalyst, and as the concentration increases, the nickel extraction rate is significantly improved, but the co-extraction of Al and Fe impurities is less.

[0193] From all the application examples, it can be seen that the organic phase provided by the application has high universality, and can achieve separation between nickel and cobalt regardless of the source of the aqueous solution to be extracted, and can also achieve separation between nickel, cobalt and other impurities, and the key is that the extraction rate of nickel and cobalt is high.

[0194] The embodiments of the present application are described in detail above with reference to the accompanying drawings, but the present application is not limited to the above-described embodiments, and various changes can be made within the knowledge of those skilled in the art without departing from the spirit of the present application. Furthermore, the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

Claims

1. A ligand, characterized in that, The ligand has a structure as shown in formula I: wherein R is a linear or branched chain C 12 alkyl group or a branched C 12 alkyl group.

2. A method of preparing a ligand as claimed in claim 1, characterized in that, The preparation method comprises subjecting 2-(1H-pyrazol-3-yl)pyridine and R-Br to nucleophilic substitution reaction.

3. An organic phase characterized in that, The raw material of the organic phase comprises ligand, extractant and diluent; the extractant comprises dinonyl naphthalene sulfonic acid; The ligand has a structure as shown in formula I: Where R is C4, C8, C 12 Straight-chain alkyl or branched C 12 alkyl; The molar ratio of the extractant and the ligand is 1-1.5:

1.

4. The organic phase according to claim 3, characterized in that, The concentration of the extractant in the organic phase is 0.01-0.5 mol / L.

5. Use of an organic phase as claimed in claim 3 or 4 in nickel / cobalt extraction, characterized in that, The nickel / cobalt extraction comprises subjecting the organic phase to first extraction on the aqueous solution to be extracted; The aqueous solution to be extracted comprises at least one of nickel ion and cobalt ion.

6. Use according to claim 5, characterized in that, The pH of the aqueous solution to be extracted is 1.5-3.

0.

7. Use according to claim 5, characterized in that, The O / A ratio of the first extraction is 0.25-4:

1.

8. Use according to claim 5, characterized in that, When the aqueous solution to be extracted comprises nickel ion and cobalt ion; the nickel / cobalt extraction further comprises subjecting the organic phase to second extraction on the raffinate phase obtained from the first extraction.

9. Use according to claim 5, characterized in that, The nickel / cobalt extraction further comprises subjecting the primary loaded organic phase obtained from the first extraction to stripping.

10. Use according to claim 9, characterized in that, In the stripping of the primary loaded organic phase, the aqueous phase used is acid aqueous solution.

11. Use according to claim 10, characterized in that, H + concentration between 0.2 and 4 mol / L.

12. The use according to claim 9, characterized in that, In the stripping of the primary loaded organic phase, the O / A ratio is 1:1-5.

13. The use according to claim 9, characterized in that, The nickel / cobalt extraction further comprises subjecting the blank organic phase obtained from the stripping to washing, to obtain regenerated organic phase.

14. The use according to any one of claims 5 to 13, characterized in that, The aqueous solution to be extracted also includes at least one of Mn 2 + , Mg 2+ , Al 3+ , Ca 2+ , Zn 2+ , and Fe 3+ .

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