Benzene-ring-based mono-pyridine extraction agent, preparation method thereof and application of extraction agent in extraction and separation of copper, cobalt and nickel

Abstract

The invention discloses a benzene-ring-based mono-pyridine extraction agent, a preparation method thereof and application of the extraction agent in extraction and separation of copper, cobalt and nickel. The benzene-ring-based mono-pyridine extraction agent has the following structure: # imgabs0 #, wherein R is alkyl of C4-C9. The benzene-ring-based mono-pyridine extraction agent is obtained by a phenol compound and a pyridine compound through Williamson etherification reaction, the reaction raw materials are low in cost, the synthesis path is short, the reaction conditions are mild, the extraction agent is green and low-carbon, and the benzene-ring-based mono-pyridine extraction agent has good complexing ability on copper ions, cobalt ions and nickel ions in an ammonia solution system and can be used for preparing a high-purity benzene-ring-based mono-pyridine extraction agent. Particularly, the method has high selectivity on extraction of copper ions, cobalt ions and nickel ions under different pH conditions, and is suitable for extraction and separation of copper ions, cobalt ions and nickel ions.

Description

Technical Field

[0001] The invention relates to a benzene ring based monopyridine extractant, a preparation method of the benzene ring based monopyridine extractant, and application of the benzene ring based monopyridine extractant in selectively extracting and separating copper, cobalt and nickel in an ammonia solution, and belongs to the fields of fine chemicals and hydrometallurgy. Background Art

[0002] Copper, cobalt and nickel, as important industrial raw materials, play an important role in the fields of steel, batteries and magnetic materials. With the rapid development of the new energy industry in recent years, they have attracted widespread attention and have become indispensable basic materials and strategic resources for the development of emerging industries. In the field of modern metallurgy, the smelting technology of copper, cobalt and nickel mainly focuses on the development and utilization of high-grade mineral resources. However, due to the increasing difficulty of mining mineral resources, the gradual reduction of mineral grade and the decreasing resource reserves, the development of new technologies and process flows that are suitable for the treatment of diversified mineral resources such as low-grade complex ores, tailings, and seabed manganese nodules has become an important direction for the development of the copper, cobalt and nickel metallurgical industry.

[0003] Hydrometallurgy has become the preferred choice for the development of copper, cobalt and nickel resources due to its advantages of low cost, high utilization rate, environmental protection and ability to process a variety of mineral resources. The process includes dissolving valuable elements, separating leachate, purifying leachate and recovering copper, cobalt and nickel. Common processes include acid leaching-purification-electrodeposition, ammonia leaching-extraction-electrodeposition, bioleaching-electrodeposition, etc. The acid extraction process mainly uses leaching agents such as sulfuric acid and hydrochloric acid to treat oxidized ores or minerals that are easily soluble in acid. It has the advantages of high leaching efficiency, cheap leaching agents and simple operation. However, when treating alkaline gangue minerals, the acid consumption is high, the selectivity is poor, and the impurity content is high. It is more suitable for treating simple oxidized minerals. Ammonia extraction uses ammonia water or ammonium salts as leaching agents, which can convert valuable metal ions in the ore into complexes and separate them from the minerals. It is widely used in cobalt, nickel and copper hydrometallurgy, and is particularly suitable for treating high-alkaline gangue-type low-grade minerals. For laterite nickel ores with high magnesium oxide content, acid leaching is expensive, so ammonia leaching became the earliest wet process used to treat such ores.

[0004] For high-grade mineral leachate, it is necessary to purify and remove impurities to facilitate subsequent production. However, for low-grade mineral leachate, the concentration of copper, cobalt and nickel ions is low, and there are many calcium and magnesium impurities, which makes the subsequent process difficult. To produce high-quality products from complex minerals, it is necessary to separate copper, cobalt and nickel to increase the concentration of metal ions. Solvent extraction is an important separation technology with simple process, high separation efficiency, low investment and low energy consumption. Therefore, it is very important to develop an extraction process suitable for the separation and purification of copper, cobalt and nickel ions in ammonia systems.

[0005] In the ammonia extraction process for copper, cobalt and nickel, the selection of extractants is crucial. At present, the mainstream extractants on the market mainly include ketoximes, aldoximes and β-diketones. Ketoxime extractants are widely used in the commercial field due to their good physical properties and chemical stability, such as LIX63, LIX64, etc. They have good phase separation effect, low entrainment loss, and are easy to strip, but compared with aldoximes, their extraction capacity is slightly insufficient, the saturation capacity is low, and the kinetic process is relatively slow under low temperature conditions. Aldoxime extractants such as LIX860 and P50 stand out for their fast mass transfer kinetics and strong extraction ability. However, their stripping process is more difficult, and their chemical stability is slightly inferior to that of ketoxime extractants, so they often need to be used in combination with modifiers in practical applications. β-diketone extractants have excellent performance and perform outstandingly in high-ammonia and high-copper solutions. However, this type of extractant also has strong extraction ability for nickel and cobalt, and lacks selectivity. The existing co-extraction-selective stripping method can achieve separation and purification, but high concentrations of nickel and cobalt will reduce the copper saturation capacity, increase the number of extraction and stripping stages, lead to increased consumption of organic extractants and acids, and produce a large amount of acidic wastewater. From an economic and environmental perspective, this method is not a long-term solution. Therefore, in the wet process, how to effectively separate nickel, cobalt and copper elements in ammonia solution remains a challenging problem. To solve this problem, it is necessary to design and synthesize a low-cost and efficient extractant to promote technological progress and sustainable development. Summary of the invention

[0006] In view of the technical defects of the pyridine extractants in the prior art for selectively extracting and separating copper, cobalt, nickel, etc., the first object of the present invention is to provide a benzene ring-based monopyridine extractant, which has a good extraction effect on copper ions, cobalt ions and nickel ions in an ammonia solution system, especially different selective extraction capacities for copper ions, cobalt ions and nickel ions under different pH environments, thereby achieving selective extraction and separation of copper ions, cobalt ions and nickel ions in an ammonia solution system, and has the characteristics of good stability, large saturation capacity, good circulation performance, high extraction efficiency, etc.

[0007] The second object of the present invention is to provide a method for preparing a phenyl ring-based monopyridine extractant, which has the advantages of cheap raw materials, simple process route, mild reaction conditions, high yield and productivity, and is suitable for large-scale industrial production.

[0008] The third object of the present invention is to provide a benzene ring-based monopyridine extractant for use as an extractant for copper ions, cobalt ions and nickel ions. The benzene ring-based monopyridine extractant has strong selective separation and extraction efficiency for copper ions, cobalt ions and nickel ions in ammonia solution systems at different pH values, is very suitable for industrial applications for step-by-step recovery of copper, cobalt and nickel, and can effectively solve the technical problem of separation and purification of copper, cobalt and nickel in the industry.

[0009] In order to achieve the above technical purpose, the present invention provides a benzene ring-based monopyridine extractant having

[0010] The structure shown in formula 1:

[0011]

[0012] Wherein, R is a C4-C9 alkyl group.

[0013] In the benzene ring-based monopyridine extractant of the present invention, R is an alkyl group of C4 to C9, wherein the alkyl group may be a straight-chain alkyl group or a branched alkyl group, more specifically, it may be a tert-butyl group, an isooctyl group, a nonyl group, etc., and the most preferred R is a tert-butyl group or an isooctyl group. The substitution position of R is not limited and may be the ortho, meta or para position of the benzene ring. The length of the carbon chain will have a great influence on the solubility of the extractant. A carbon chain that is too short will cause the extractant to be too water-soluble, and it will not be able to form an extractant with the target metal during the extraction process and enter the oil phase. At the same time, the extractant itself is unstable and easily emulsified; a carbon chain that is too long will cause the viscosity of the extractant to increase, the complexity of the purification process will increase, and the phase separation effect will be poor during the extraction process, and three phases will be easily formed.

[0014] As a preferred embodiment, R in the benzene ring-based monopyridine extractant is tert-butyl or isooctyl.

[0015] The benzene ring monopyridine extractant of the present invention has a special molecular structure, and its main structure is a pyridine active coordination group. The benzene ring group is replaced by an ether bond on one side of the main structure. The introduction of the benzene ring group can improve the oil solubility and stability of the entire molecular structure, shorten the phase separation time after extraction, and the introduction of the alkoxy group as an electron-withdrawing group can provide the ability of the N atom to bind protons, which is conducive to the exchange of the extractant and the coordinated water molecules, thereby increasing the saturation capacity of the extractant, and the O atom has a coordination effect on the metal ion, and forms a good co-coordination with the N atom of the pyridine group, thereby improving the extraction and separation efficiency of the benzene ring monopyridine extractant for copper ions, cobalt ions, and nickel ions. The introduction of an alkyl group on the benzene ring increases the electron cloud density on the benzene ring, destroys the structure of the electron cloud uniformly distributed on the benzene ring, causes the electron cloud to migrate to the hydroxyl-containing carbon, increases the electron-withdrawing effect of the oxygen atom, and increases the reaction rate and activity of phenol and chloropyridine, and the introduction of the alkyl group increases the stability of the extractant, reduces its water solubility, and increases the phase separation performance of the extractant.

[0016] The benzene ring-based monopyridine extractant of the invention has a moderate molecular weight, a large solubility of the extractant in the organic phase, a fast extraction phase separation speed, and avoids the problems of emulsification and phase separation difficulties.

[0017] The present invention also provides a method for synthesizing a benzene ring-based monopyridine extractant, wherein the method comprises subjecting a phenol compound of formula 2 and a pyridine compound of formula 3 to a Williamson reaction to obtain;

[0018]

[0019]

[0020] in,

[0021] R is a C4-C9 alkyl group;

[0022] X is a halogen substituent, which can be a chlorine substituent or a bromine substituent.

[0023] As a preferred embodiment, the molar ratio of the phenol compound to the pyridine compound is 1:(1-2). The molar ratio of phenol to chloromethylpyridine is more preferably 1:(1.2-1.5). The phenol compound is more preferably p-tert-butylphenol, p-isooctylphenol, p-nonylphenol, etc.

[0024] As a preferred solution, the conditions of the Williamson reaction are: under the catalytic action of a base, at 60 to 90° C., for 8 to 20 hours. Further preferably, the base is a weak base, such as sodium carbonate or potassium carbonate, and the equivalent ratio of the base to chloromethylpyridine hydrochloride is 1:2. Further preferably, the solvent used in the Williamson reaction can be selected from acetonitrile, cyclohexane, benzene, etc., which can ensure a higher yield of the reaction under the preferred reaction conditions.

[0025] The specific reaction equation of the synthesis process of the benzene ring-based monopyridine extractant of the present invention is as follows (taking p-tert-butylphenol and 2-chloromethylpyridine hydrochloride as examples for illustration):

[0026]

[0027] The specific preparation method of the benzene ring monopyridine extractant provided by the present invention is as follows (taking the optimal synthesis method as an example for illustration, taking p-tert-butylphenol and 2-chloromethylpyridine hydrochloride as examples for illustration): 1eq tert-butylphenol and 1.5eq chloromethylpyridine hydrochloride are dissolved in 2eq acetonitrile and added into a three-necked flask, and 1% to 3% tetrabutylammonium bromide is added under the catalysis of 1eq potassium carbonate, and the reaction is stopped after 20h at 80°C, and the solvent acetonitrile in the organic phase is recovered by a rotary evaporator at 100°C, and the resultant is dissolved in cyclohexane, and washed 4 to 5 times with 1mol / L sulfuric acid and an appropriate amount of pure water, and the organic phase and the aqueous phase are separated, and the cyclohexane is recovered by a rotary evaporator to obtain a benzene ring monopyridine extractant BMPY, with a yield of 91.52%, a yield of 86.33%, and a product purity of ≥95%. The specific structural formula is as follows:

[0028]

[0029] The present invention also provides an application of a benzene ring-based monopyridine extractant, which is applied as an extractant for copper ions, cobalt ions and nickel ions.

[0030] As a preferred solution, the extractant is used for the stepwise extraction and separation of copper ions, cobalt ions and nickel ions in an ammonia solution system. In the ammonia solution system, copper ions, cobalt ions and nickel ions exist mainly in the form of free ions and ammonia complexes in the ammonia solution.

[0031] As a preferred solution, copper ions are first extracted under the condition of pH>7 and ≤7.5, cobalt ions are then extracted under the condition of pH>8 and ≤9.5, and nickel ions are then extracted under the condition of pH>10 and ≤10.5. The optimal pH values ​​for extracting copper ions, cobalt ions and nickel ions from an ammonia solution by the benzene ring-based monopyridine extractant of the present invention are 7.3, 9.50 and 10.30, respectively.

[0032] As a preferred scheme, an organic phase containing the extractant is used to extract an ammonia solution system containing copper ions, cobalt ions and nickel ions in steps under different pH conditions from low to high to obtain a copper-loaded organic phase, a cobalt-loaded organic phase and a nickel-loaded organic phase, respectively. The copper-loaded organic phase, the cobalt-loaded organic phase and the nickel-loaded organic phase are washed and stripped to obtain a copper-rich stripping solution, a cobalt-rich stripping solution and a nickel-rich stripping solution.

[0033] As a preferred solution, the concentration of the extractant in the organic phase containing the extractant is 0.5-0.8 mol / L. It is further preferred that the concentration of the benzene ring monopyridine extractant is 0.75 mol / L. The organic phase also contains a phase regulator and a diluent; the phase regulator is at least one of n-octanol, isooctyl alcohol, sec-octanol, and TBP, and the phase regulator accounts for 5% to 20% of the volume of the organic phase. The organic phase also contains an organic diluent, specifically at least one of sulfonated kerosene, high carbon alcohol, solvent oil, and kerosene, and the content of the organic diluent accounts for 70% to 90% of the volume of the organic phase. The extraction system composed of the benzene ring monopyridine extractant, appropriate isooctyl alcohol and solvent oil has a significant effect on the extraction and separation of copper ions, cobalt ions, and nickel ions in ammonia solution.

[0034] As a preferred solution, the concentrations of copper ions, cobalt ions and nickel ions in the ammonia solution system containing copper ions, cobalt ions and nickel ions are all less than 20 g / L. The anions in the ammonia solution system are mainly sulfate ions.

[0035] As a preferred solution, the extraction adopts a multi-stage countercurrent extraction method, the extraction stages are 1 to 4, and the oil-water volume flow ratio is 1:3 to 3:1.

[0036] As a preferred solution, the stripping agent is an acid solution with a concentration of 1 to 1.2 mol / L.

[0037] As a preferred solution, the washing adopts a sulfuric acid solution with a concentration of 0.1 to 0.2 mol / L as a washing liquid. The washing process mainly removes some impurity ions extracted or entrained by the benzene ring monopyridine extractant, and the non-target metal ions in the loaded organic phase can be returned to the extraction tank after washing treatment for cyclic extraction. The washing liquid is at least one of sulfuric acid, hydrochloric acid, and nitric acid solution.

[0038] As a preferred solution, the washing adopts multi-stage countercurrent washing, the washing stages are 1 to 3, and the volumes of the copper-loaded organic phase, the cobalt-loaded organic phase, the nickel-loaded organic phase and the washing liquid are 10:1, 5:1, and 5:1 respectively.

[0039] As a preferred solution, the stripping agent is a sulfuric acid solution with a concentration of 1 to 1.2 mol / L. The stripping solution is at least one of sulfuric acid, hydrochloric acid and nitric acid solution.

[0040] As a preferred solution, the stripping adopts multi-stage countercurrent stripping, the stripping stage number is 1 to 3, and the volume of the copper-loaded organic phase, the cobalt-loaded organic phase, the nickel-loaded organic phase and the stripping agent is 5:1.

[0041] The method for using a benzene ring-based monopyridine extractant provided by the present invention in extracting and separating copper ions, cobalt ions, and nickel ions in an ammonia solution system comprises the following steps:

[0042] 1) The pH of the solution for extracting copper, cobalt and nickel is 7 to 10.5, and the concentration of copper, cobalt and nickel is 0 to 20 g / L;

[0043] 2) The organic phase modified and diluted by the benzene ring monopyridine extractant is stirred, and then the solutions containing copper, cobalt and nickel are extracted at pH = 7.3, 9.50 and 10.30 respectively, so that copper, cobalt and nickel enter the organic phase respectively, and the impurity metals remain in the aqueous phase, thereby achieving deep separation of copper, cobalt and nickel in copper, cobalt and nickel ammonia solutions of different pH.

[0044] 3) The loaded organic phase is washed with a detergent, and then stripped with a stripping agent to obtain a copper-rich stripping solution, a cobalt-rich stripping solution, and a nickel-rich stripping solution, respectively. The blank organic phase after stripping is recycled to the extraction stage.

[0045] The technical principle of the benzene ring-based monopyridine extractant of the present invention for extracting, separating and purifying copper ions, cobalt ions and nickel ions in ammonia solutions containing copper ions, cobalt ions and nickel ions at different pH values ​​is as follows: when the pH value in the solution is in a range favorable for the formation of complex ions of low-valent metals, divalent copper ions, cobalt ions and nickel ions can react with ammonia to form different ammonia complexes. eq Next, Cu 2+ 、Ni 2+ and Co 2+ The complexes with ammonia have different forms, and the stability and affinity of the complexes with the extractant are different, resulting in different extraction efficiencies of various metals. 2+ 、Ni 2 + 、Co 2+ pH eq When Cu is greater than 7.3, 9.5, and 10.3, respectively, 2+ 、Ni 2+ 、Co 2+ The complexation with diamine, triamine, tetraamine, and pentaamine complexes of ammonia is activated, resulting in a decrease in the concentration of free metal ions. This leads to a significant decrease in the extraction efficiency. Therefore, the extraction process is dominated by a single free metal ion because there is enough OH - , but lacks the complexed free metal ions to achieve complete extraction.

[0046] At low pH, the metal ions of the extractant are coordinated, and the metal ammonia complex is hydrolyzed, the previous ammonia complex is hydrolyzed, and the extraction efficiency increases. However, as the pH rises, the free ammonia in the solution increases, which is not conducive to the dissociation of the ammonia complexes of copper ions, cobalt ions, and nickel ions, inhibiting the reaction activity and resulting in a decrease in extraction efficiency. Another reason for the decrease may be that the free ammonia in the solution competes with the extractant to bind to the metal ions.

[0047] It is particularly noteworthy that although nickel ions, cobalt ions and copper ions can be extracted together by the extractant, copper ions can reach extraction equilibrium faster than nickel ions and cobalt ions. This is because copper ions are four-coordinate structures and form (Cu(NH3)4 2+ ), with a planar square structure, BMPY is more likely to replace the inner layer coordinated water molecules, and the copper ammonia complex structure is also easier to coordinate under this structure. The nickel ion and cobalt ion form a hexacoordinate structure (Ni(NH3)6 2+ ), (Co(NH3)6 2+ ) complex, with a higher stability constant (K[Co(NH3)6 2+ ]=1035.2,K[Ni(NH3)6 2+]=108.74), forming a more stable complex with ammonia. The extraction rate of copper ions is lower than that of copper ions, indicating that the extraction rate of valuable metals in ammonia solution mainly depends on their form.

[0048] Compared with the existing technology, the technical solution of the present invention brings the following beneficial technical effects:

[0049] 1) Compared with the existing mainstream copper, cobalt and nickel extractants, the benzene ring-based monopyridine extractant provided by the present invention has lower raw material cost, simple process route, short process, mild conditions, stable reaction, and is suitable for large-scale industrial application.

[0050] 2) The method for extracting and separating copper ions, cobalt ions and nickel ions in an ammonia solution system using a benzene ring-based monopyridine extractant of the present invention has high selectivity, large saturation capacity and high separation coefficient, and is suitable for extracting and separating copper ions, cobalt ions and nickel ions in high-nickel-cobalt and low-copper feed solutions and high-copper and low-nickel-cobalt feed solutions, and has good application prospects.

[0051] 3) The present invention can obtain copper-rich, cobalt-rich and nickel-rich sulfuric acid purification solutions respectively.

[0052] 4) The extraction process of the benzene ring-based monopyridine extractant of the present invention is carried out at room temperature. After the extraction is completed, the phase separation speed is fast, the phase separation time is short, the oil-water phases are obvious, and no third phase is generated, thereby effectively achieving extraction, separation, and purification.

[0053] 5) The benzene ring-based monopyridine extractant of the present invention consumes only inorganic acid and alkali during the extraction and separation process, the reagent is cheap and safe, the operating cost is low, the operating environment is good, it meets environmental protection requirements, and reduces production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Figure 1 This is the H1 NMR spectrum of the Williamson reaction product in Example 1.

[0055] Figure 2 is the carbon nuclear magnetic resonance spectrum (C1 NMR) of the Williamson reaction product in Example 1.

[0056] Figure 3 This is the high resolution mass spectrum (HRMS) of the Williamson reaction product in Example 1.

[0057] Figure 4 This is a graph showing the effect of equilibrium pH on the extraction rates of copper ions, cobalt ions and nickel ions during the extraction and separation of copper ions, cobalt ions and nickel ions using 2-((4-butylphenoxy)methyl)pyridine in Example 5.

[0058] Figure 5This is a graph showing the effect of 2-((4-butylphenoxy)methyl)pyridine on the extraction rates of copper ions, cobalt ions and nickel ions during the extraction and separation of copper ions, cobalt ions and nickel ions in Example 6.

[0059] Figure 6 This is a graph showing the effect of extraction time on the extraction rates of copper ions, cobalt ions and nickel ions during the extraction and separation of copper ions, cobalt ions and nickel ions using 2-((4-butylphenoxy)methyl)pyridine in Example 7.

[0060] Figure 7 This is a graph showing the effect of the concentration of the extractant on the extraction rate of copper ions, cobalt ions and nickel ions during the extraction and separation of copper ions, cobalt ions and nickel ions using 2-((4-butylphenoxy)methyl)pyridine in Example 8.

[0061] Figure 8 This is a graph showing the effect of total ammonia concentration on the extraction rates of copper ions, cobalt ions and nickel ions during the extraction and separation of copper ions, cobalt ions and nickel ions using 2-((4-butylphenoxy)methyl)pyridine in Example 9.

[0062] Fig. 9 This is a full flow chart of "extraction-washing-strip extraction" in the process of extracting and separating copper ions, cobalt ions and nickel ions using 2-((4-butylphenoxy)methyl)pyridine in Example 10. DETAILED DESCRIPTION

[0063] In order to better understand the present invention, the present invention is further described below through specific implementation methods, but the examples listed do not limit the protection scope of the present invention.

[0064] Example 1

[0065] Preparation of 2-((4-butylphenoxy)methyl)pyridine:

[0066] First, 30.1g (0.2mol) of p-tert-butylphenol was dissolved in 80ml acetonitrile and added to a three-necked round-bottom flask. Then the reactant was stirred at 70°C, and 180ml of an aqueous solution containing 53.0g (0.5mol) potassium carbonate and 1.0g tetrabutylammonium bromide was slowly added. After standing for 0.5 hours, 100ml of anhydrous methanol solution dissolved with 65.6g (0.4mol) 2-(chloromethyl) pyridine hydrochloride was gradually added dropwise, and thin layer chromatography was used to monitor the reaction process. After the reaction was completed, the residual catalyst was removed by filtration, and the excess solvent was removed by vacuum distillation to obtain a brown viscous liquid. Then it was dissolved with an appropriate amount of tetrachloroethane, acid washed with 10% dilute sulfuric acid solution, washed with saturated sodium chloride solution, washed with water to neutrality, dried with anhydrous magnesium chloride, and the organic phase was collected and distilled under reduced pressure. After final drying, 55.0g of light yellow viscous liquid (BMPY) (yield 95.87%, purity greater than 95%) was obtained.

[0067] Example 2

[0068] Preparation of 2-((4-octylphenoxy)methyl)pyridine:

[0069] First, 41.2g (0.2mol) of 4-tert-octylphenol was dissolved in 80ml acetonitrile and added to a three-necked round-bottomed flask. Then the reactant was stirred at 70°C, and 180ml of an aqueous solution containing 53.0g (0.5mol) potassium carbonate and 1.0g tetrabutylammonium bromide was slowly added. After standing for 0.5 hours, 100ml of anhydrous methanol solution dissolved with 65.6g (0.4mol) 2-(chloromethyl) pyridine hydrochloride was gradually added dropwise, and thin layer chromatography was used to monitor the reaction process. After the reaction was completed, the residual catalyst was removed by filtration, and the excess solvent was removed by vacuum distillation to obtain a brown viscous liquid. Then it was dissolved with an appropriate amount of tetrachloroethane, acid washed with 10% dilute sulfuric acid solution, washed with saturated sodium chloride solution, washed with water to neutrality, dried with anhydrous magnesium chloride, and the organic phase was collected and vacuum distilled. After final drying, 62.12g of dark yellow viscous liquid (yield 96.12%, purity greater than 95%) was obtained.

[0070] Example 3

[0071] Preparation of 2-((4-nonylphenoxy)methyl)pyridine:

[0072] First, 44.1g (0.2mol) of p-nonylphenol was dissolved in 80ml acetonitrile and added to a three-necked round-bottomed flask. Then the reactant was stirred at 70°C, and 180ml of an aqueous solution containing 53.0g (0.5mol) potassium carbonate and 1.0g tetrabutylammonium bromide was slowly added. After standing for 0.5 hours, 100ml of anhydrous methanol solution dissolved with 65.6g (0.4mol) 2-(chloromethyl) pyridine hydrochloride was gradually added dropwise, and thin layer chromatography was used to monitor the reaction process. After the reaction was completed, the residual catalyst was removed by filtration, and the excess solvent was removed by vacuum distillation to obtain a brown viscous liquid. Then it was dissolved with an appropriate amount of tetrachloroethane, acid washed with 10% dilute sulfuric acid solution, washed with saturated sodium chloride solution, washed with water to neutrality, dried with anhydrous magnesium chloride, and the organic phase was collected and vacuum distilled. After final drying, 64.55g of dark yellow paste liquid was obtained. (yield 95.88%, purity greater than 95%).

[0073] Example 4

[0074] Scale-up experimental preparation of 2-((4-butylphenoxy)methyl)pyridine:

[0075] First, 150.2g (1mol) of p-tert-butylphenol was dissolved in 200ml of acetonitrile and added to a three-necked round-bottom flask. Then the reactant was stirred at 70°C, and 180ml of an aqueous solution containing 138g (1mol) of potassium carbonate and 3.0g of tetrabutylammonium bromide was slowly added. After standing for 0.5 hours, 2ml of anhydrous methanol solution dissolved with 164g (1mol) of 2-(chloromethyl)pyridine hydrochloride was gradually added dropwise, and thin layer chromatography was used to monitor the reaction process. After the reaction was completed, the residual catalyst was removed by filtration, and the excess solvent was removed by vacuum distillation to obtain a brown viscous liquid. Then it was dissolved with an appropriate amount of tetrachloroethane, acid washed with 10% dilute sulfuric acid solution, washed with saturated sodium chloride solution, washed with water to neutrality, dried with anhydrous magnesium chloride, and the organic phase was collected and vacuum distilled. After final drying, 228.95g of light yellow viscous liquid BMPY (yield 95.87%, purity greater than 95%) was obtained.

[0076] Example 5

[0077] 200mL of simulated leaching solution containing 1g / L copper, cobalt and nickel was prepared as the aqueous phase to be extracted, and the ammonia concentration and initial pH were controlled by a ternary (ammonia + ammonium sulfite + ammonium carbonate) system and 1mol / L sodium hydroxide. An organic phase was prepared, wherein the organic phase contained 0.75mol / L BMPY, the diluent was solvent oil, and the polar modifier was 20% isooctyl alcohol by volume, with a phase ratio of 1:1. Under the conditions that the pH of the aqueous phase was 7.3, 9.5, and 10.3 and the total ammonia concentration was 1mol / L, the three aqueous phases with different pH values ​​were contacted with the organic phase respectively, and after oscillation in a water bath at room temperature of 25°C for 10min, the layers were allowed to stand and separate. After the phase separation was complete, the metal ion concentration in the raffinate was determined by inductively coupled plasma emission spectroscopy (ICP-OES), and the metal ion concentration in the organic phase was obtained by subtraction.

[0078] from Figure 4 The results of the extraction experiment show that the equilibrium pH has a great influence on the extraction and separation efficiency of nickel, cobalt and manganese in ammonia solution. When the pH ranges from 4 to 11, the extraction rate of copper, cobalt and nickel by BMPY shows a trend of first increasing and then decreasing, and the extraction order of the three metals is Cu>Co>Ni. According to the gradual extraction of target metals at different pH values, pH 7.3, 9.5 and 10.3 were selected as the optimal pH to extract copper, nickel and cobalt. The reason may be that at low pH, the extractant coordinates with the valuable metal in the outer layer, and at the same time, the metal ammonia complex is hydrolyzed, the previous ammonia complex is hydrolyzed, and the extraction efficiency increases. However, with the increase of pH, the free ammonia in the solution increases, which is not conducive to the dissociation of the ammonia complexes of copper, cobalt and nickel, inhibits the reaction activity, and leads to a decrease in the extraction efficiency. In addition, another reason for the decrease may be that the free ammonia in the solution competes with the extractant to bind metal ions.

[0079] Comparative Example 1

[0080] 200mL of simulated leaching solution of sulfate system containing 1g / L copper, cobalt and nickel was prepared as the aqueous phase to be extracted, and 1mol / L dilute sulfuric acid and 1mol / L sodium hydroxide were used to control the ammonia concentration and initial pH. An organic phase was prepared, wherein the organic phase contained 0.75mol / L 2-((4-octylphenoxy)methyl)pyridine, the diluent was solvent oil, and the polar modifier was 20% isooctyl alcohol by volume, with a phase ratio of 1:1. Under the conditions of aqueous phase pH of 1, 2, 3, 4, 5, 6, and 7, the aqueous phases of different pH were contacted with the organic phase respectively, and after oscillation in a water bath at room temperature of 25°C for 10min, the phases were allowed to stand and separate. After the phase separation was complete, the metal ion concentration in the raffinate was determined by inductively coupled plasma optical emission spectroscopy (ICP-OES), and the metal ion concentration in the organic phase was obtained by subtraction. After measurement, the extraction rates of copper, cobalt and nickel were basically consistent with the results of the BMPY extraction experiment. However, during the phase separation process after shaking, a third phase was generated between the organic phase and the aqueous phase, and the elimination time of the third phase under heating was 1 hour. The phase separation effect was poor, which was not conducive to the full-process extraction process.

[0081] Comparative Example 2

[0082] 200mL of simulated leaching solution of sulfate system containing 1g / L copper, cobalt and nickel was prepared as the aqueous phase to be extracted, and 1mol / L dilute sulfuric acid and 1mol / L sodium hydroxide were used to control the ammonia concentration and initial pH. The organic phase was prepared, wherein the organic phase contained 0.75mol / L 2-((4-nonylphenoxy)methyl)pyridine, the diluent was solvent oil, and the polar modifier was 20% isooctyl alcohol by volume, with a relative ratio of 1:1. Under the conditions of aqueous phase pH of 1, 2, 3, 4, 5, 6, and 7, the aqueous phases of different pH were contacted with the organic phase respectively, and the phases were allowed to stand for stratification after oscillation in a water bath at room temperature of 25°C for 10min. After the phase separation was complete, the metal ion concentration in the raffinate was determined by inductively coupled plasma emission spectroscopy (ICP-OES), and the metal ion concentration in the organic phase was obtained by subtraction. After measurement, the extraction efficiency of copper, cobalt and nickel was basically consistent with the results of subsequent BMPY extraction experiments. However, the viscosity of the organic phase itself is too high, and purification is more troublesome during the synthesis process. During the preparation of the organic phase, the stirring time of the organic phase was too long, and due to the high viscosity, it was severely adhered to the aqueous phase during the phase separation process, and the phase separation time was long, which was not conducive to the full-process extraction process.

[0083] Comparative Example 3

[0084] 200mL of simulated leaching solution of the sulfate system containing 1g / L copper, cobalt and nickel was prepared as the aqueous phase to be extracted, and 1mol / L dilute sulfuric acid and 1mol / L sodium hydroxide were used to control the ammonia concentration and the initial pH. The organic phase was prepared, wherein the organic phase contained 0.75mol / L BMPY, the diluent was solvent oil, and the polar modifier was 20% isooctyl alcohol by volume, with a phase ratio of 1:1. Under the conditions of aqueous phase pH of 1, 2, 3, 4, 5, 6, and 7, the aqueous phases with different pH values ​​were contacted with the organic phase respectively, and after oscillation in a water bath at room temperature of 25°C for 10 minutes, the aqueous phases were allowed to stand and separate. After the phase separation was complete, the metal ion concentration in the raffinate was determined by inductively coupled plasma emission spectroscopy (ICP-OES), and the metal ion concentration in the organic phase was obtained by subtraction. After measurement, it was found that under the sulfate system, when the pH was in the range of 1 to 7, the extraction rates of copper, cobalt and nickel metals by BMPY were all below 10%, and β Cu / Ni , β Cu / Co , β Co / Ni The separation coefficient is low and cannot meet the extraction and separation requirements.

[0085] Example 6

[0086] 200mL of simulated leaching solution containing 1g / L copper, cobalt and nickel was prepared as the aqueous phase to be extracted, and the ammonia concentration and initial pH were controlled by ammonia and ammonium salt system and 1mol / L sodium hydroxide. The organic phase was prepared, wherein the organic phase contained 0.75mol / L BMPY, the diluent was solvent oil, and the polar modifier was 20% isooctyl alcohol by volume, and the phase ratios were 1:3, 1:2, 1:1, 2:1, and 3:1, respectively. Under the conditions that the pH of the aqueous phase was 7.3, 9.5, and 10.3 and the total ammonia concentration was 1mol / L, the three aqueous phases with different pH values ​​were contacted with the organic phase at different ratios, and the phases were allowed to stand and separate after oscillation in a water bath at room temperature of 25°C for 10min. After the phase separation was complete, the metal ion concentration in the raffinate was determined by inductively coupled plasma emission spectroscopy (ICP-OES), and the metal ion concentration in the organic phase was obtained by subtraction.

[0087] exist Figure 5 It can be found that as the O / A ratio increases, the concentration of the extractant in the solution increases, which increases the extraction efficiency of copper, cobalt and nickel. When the O / A ratio is greater than 1, the extraction efficiency of the three target metals tends to be balanced at the optimal pH, the target metals in the aqueous phase are basically extracted, and the excess BMPY begins to extract other impurity ions.

[0088] Example 7

[0089] 200mL of simulated leaching solution containing 1g / L copper, cobalt and nickel was prepared as the aqueous phase to be extracted, and the ammonia concentration and initial pH were controlled by ammonia and ammonium salt system and 1mol / L sodium hydroxide. An organic phase was prepared, wherein the organic phase contained 0.75mol / L BMPY, the diluent was solvent oil, and the polar modifier was 20% isooctyl alcohol by volume, with a phase ratio of 1:1. Under the conditions of aqueous phase pH of 7.3, 9.5, and 10.3 and a total ammonia concentration of 1mol / L, the three aqueous phases with different pH values ​​were contacted with the organic phases respectively, and the aqueous phases were oscillated in a water bath at room temperature of 25°C for 0 to 25min and then allowed to stand for stratification. After the phase separation was complete, the metal ion concentration in the raffinate was determined by inductively coupled plasma emission spectroscopy (ICP-OES), and the metal ion concentration in the organic phase was obtained by subtraction.

[0090] exist Figure 6 The extraction kinetics of the reaction can be observed, and the extraction process reaches equilibrium in 5 to 10 minutes.

[0091] Example 8

[0092] 200mL of simulated leaching solution containing 1g / L copper, cobalt and nickel was prepared as the aqueous phase to be extracted, and the ammonia concentration and initial pH were controlled by ammonia and ammonium salt system and 1mol / L sodium hydroxide. An organic phase was prepared, wherein the organic phase contained 0-0.8mol / L BMPY, the diluent was solvent oil, and the polar modifier was 20% isooctyl alcohol by volume, with a phase ratio of 1:1. Under the conditions of aqueous phase pH of 7.3, 9.5, and 10.3 and a total ammonia concentration of 1mol / L, the three aqueous phases with different pH values ​​were contacted with the organic phases respectively, and the phases were allowed to stand and separate after oscillation in a water bath at room temperature of 25°C for 10min. After the phase separation was complete, the metal ion concentration in the raffinate was determined by inductively coupled plasma emission spectroscopy (ICP-OES), and the metal ion concentration in the organic phase was obtained by subtraction.

[0093] like Figure 7 As shown in the figure, when the concentration of the extractant increases, the extraction efficiency begins to gradually increase, which can be attributed to the binding capacity contributed by the newly added free BMPY. However, considering the cost caused by the additional consumption of the extractant, and the increase in the viscosity of the organic phase with the increase in the concentration of BMPY in kerosene, which hinders the diffusion of metal ions and makes phase separation difficult, the O / A ratio of 1:1 is considered to be the best. On this basis, the optimal extraction conditions were determined to be 25°C, 10min of oscillation time, O / A = 1:1, and an extractant concentration of 0.75mol / L for extraction experiments.

[0094] Example 9

[0095] 200mL of simulated leaching solution containing 1g / L copper, cobalt and nickel was prepared as the aqueous phase to be extracted, and the ammonia concentration and initial pH were controlled by ammonia and ammonium salt system and 1mol / L sodium hydroxide. An organic phase was prepared, wherein the organic phase contained 0.75mol / L BMPY, the diluent was solvent oil, and the polar modifier was 20% isooctyl alcohol by volume, with a phase ratio of 1:1. Under the conditions that the pH of the aqueous phase was 7.3, 9.5, and 10.3 and the total ammonia concentration was 1.2-2.8mol / L, the three aqueous phases with different pH values ​​were contacted with the organic phases under different ammonia concentrations, and the aqueous phases were shaken in a water bath at room temperature of 25°C for 10min and then allowed to stand for stratification. After the phase separation was complete, the metal ion concentration in the raffinate was determined by inductively coupled plasma emission spectroscopy (ICP-OES), and the metal ion concentration in the organic phase was obtained by subtraction.

[0096] like Figure 8 As shown in the figure, ammonia concentration is very important for the extraction of copper, nickel and cobalt metals. Sufficient ammonia is usually required to ensure a high recovery rate. This is related to the form of metal ions in the solution and the competitive effect of free ammonia in the ammonia ion complex solution on the extraction. The extraction efficiency of metals decreases with the increase of ammonia concentration. When the total ammonia concentration increases from 1.2 mol to 2.8 mol, the extraction rate of copper decreases from 94.7% to 88.7%, and the extraction rates of nickel and cobalt also decrease significantly. The reduction in the extraction efficiency of metal ions is mainly due to the complexation of copper, cobalt and nickel ions with free ammonia in the aqueous phase to form stable metal-ammine complexes. They have higher stability constants, which hinder the extraction of metals. Therefore, in order to ensure the efficient extraction of target metal ions, the total concentration of ammonia is controlled at 1.2 mol / L.

[0097] Example 10

[0098] Under the optimal conditions: total ammonia concentration of 1.2 mol / L, temperature of 25°C, oscillation time of 10 min, O / A=1:1, BMPY concentration of 0.75 mol / L, pH values ​​of copper, cobalt and nickel in the extracted aqueous phase were 7.3, 9.5 and 10.3 respectively. In two actual feed solutions of high nickel cobalt and low copper and high copper and low nickel cobalt, the extraction isotherms of copper, cobalt and nickel were determined, and the McCabe-Thiele diagram was drawn accordingly. According to the figure, the theoretical extraction order is 4. Therefore, based on the washing and stripping data in the table, an "extraction-washing-stripping" process flow was designed to gradually extract copper, cobalt and nickel at different pH values. Fig. 9As shown in the figure, in the extraction stage, alkali is used to adjust the pH to keep it stable. At the same time, a three-stage stripping process section is designed, and a three-stage washing is designed before stripping to remove impurities. Sulfuric acid and hydrochloric acid are commonly used stripping agents, but the chloride ions in hydrochloric acid may replace the water molecules in the extraction complex to form a new complex. To avoid this phenomenon, different concentrations of sulfuric acid are used for washing-stripping. According to the flow chart, the entire process realizes green and clean production. The waste generated in this process section can flow into the next process section for continued extraction. Through the three-stage extraction process, copper, cobalt, and nickel are recovered respectively, and impurity metals are collected at the end of the process section. This process effectively realizes the one-step direct separation of copper, cobalt, and nickel. At the same time, no saponifier is used, no high-salt wastewater is generated, and the production cost is reduced, which is in line with sustainable development.

[0099] Table 1 Liquid content

[0100]

[0101] Table 2 “Extraction-Washing-Stripping” Experimental Data

[0102]

[0103]

[0104]

Claims

1. A phenyl ring-based monopyridine extractant, characterized in that: It has the structure shown in formula 1: Wherein, R is a C4-C9 alkyl group.

2. The benzene ring-based monopyridine extractant according to claim 1, characterized in that: The R is tert-butyl, isooctyl or nonyl.

3. A method for synthesizing a benzene ring-based monopyridine extractant according to claim 1 or 2, characterized in that: The phenol compound of formula 2 and the pyridine compound of formula 3 are reacted by Williamson reaction to obtain; in, R is a C4-C9 alkyl group; X is a halogen substituent.

4. The method for synthesizing a benzene ring-based monopyridine extractant according to claim 3, characterized in that: The molar ratio of the phenol compound to the pyridine compound is 1:(1-2).

5. The method for synthesizing a benzene ring-based monopyridine extractant according to claim 3 or 4, characterized in that: The conditions of the Williamson reaction are: reacting at 60-90° C. for 8-20 hours under the catalysis of a base.

6. The use of a benzene ring-based monopyridine extractant according to claim 1 or 2, characterized in that: Used as an extractant for copper ions, cobalt ions and nickel ions.

7. The use of a benzene ring-based monopyridine extractant according to claim 6, characterized in that: The extractant is used for step-by-step extraction and separation of copper ions, cobalt ions and nickel ions in an ammonia solution system.

8. The use of a benzene ring-based monopyridine extractant according to claim 7, characterized in that: First, copper ions are extracted under the condition of pH>7 and ≤7.5, then cobalt ions are extracted under the condition of pH>8 and ≤9.5, and finally nickel ions are extracted under the condition of pH>10 and ≤10.

5.

9. The use of a benzene ring-based monopyridine extractant according to any one of claims 6 to 8, characterized in that: An organic phase containing the extractant is used to extract an ammonia solution system containing copper ions, cobalt ions and nickel ions in steps under different pH conditions from low to high to obtain a copper-loaded organic phase, a cobalt-loaded organic phase and a nickel-loaded organic phase respectively. The copper-loaded organic phase, the cobalt-loaded organic phase and the nickel-loaded organic phase are washed and stripped respectively to obtain a copper-rich stripping solution, a cobalt-rich stripping solution and a nickel-rich stripping solution.

10. The use of a benzene ring-based monopyridine extractant according to claim 9, characterized in that: The concentration of the extractant in the organic phase containing the extractant is 0.5-0.8 mol / L; The concentrations of copper ions, cobalt ions and nickel ions in the ammonia solution system containing copper ions, cobalt ions and nickel ions are all no higher than 20 g / L; The ammonia concentration in the ammonia solution system is 1.2 to 2.8 mol / L; The extraction adopts a multi-stage countercurrent extraction method, the extraction stages are 1 to 4, the oil-water volume flow ratio is 1:3 to 3:1; the extraction time is not more than 25 minutes; The stripping adopts an acid solution with a concentration of 1 to 1.2 mol / L as a stripping agent.

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