Dithiazole tertiary amine-phosphate ester combination extractants, their preparation and use in nickel, cobalt, manganese extraction

Abstract

This invention belongs to the field of metal extraction, specifically relating to a dithiazole tertiary amine-phosphate combination extractant, comprising a co-extractant and an extractant, wherein the co-extractant is at least one dithiazole tertiary amine having the structure of Formula 1, and the extractant is a phosphate ester extractant; wherein R1 is C 6～14 The carbon chain or oxygen-heterocarbon chain; R2 is where n1 and n2 are 0 or 1. In this invention, the combined extractant can enhance the extraction effect of nickel and cobalt under strong acid conditions. In addition, the co-extraction of manganese can be artificially adjusted by regulating the pH balance.

Description

Technical Field

[0001] This invention relates to the field of metal extraction, specifically to the extraction of nickel, cobalt, and manganese. Background Technology

[0002] Currently, my country's clean energy industry is developing rapidly, leading to a continuous increase in demand for key metals, particularly nickel and cobalt, which are crucial metals for new energy sources. Therefore, there is an urgent need to develop more efficient, cleaner, and streamlined technologies for extracting nickel and cobalt from nickel-containing resources such as laterite nickel ore, nickel-containing waste catalysts, nickel-molybdenum ore, and electroplating sludge.

[0003] Industrially, acidic phosphine extractants are commonly used to extract and separate nickel and cobalt from nickel-cobalt sulfate solutions. Generally, chemical precipitation is used to remove large amounts of iron and aluminum, followed by deep impurity removal and extraction and separation of valuable metals using acidic phosphine extractants. P204 is relatively inexpensive and has a strong impurity extraction capability, so it is often used to remove impurities. Highly selective extractants such as PC-88A and Cyanex 272 are often used to recover and separate valuable metals such as nickel and cobalt. However, traditional extractants suffer from poor selectivity. In the process of removing impurity ions such as calcium, magnesium, and manganese, multi-stage extraction is often required, and acidic phosphine extractants such as P507 and Cyanex 272 are often used for additional impurity removal. Furthermore, because traditional acidic phosphine extractants have a low separation coefficient between nickel / cobalt and impurity metal ions, co-extraction of the target metals nickel and cobalt can occur, resulting in long washing stages and low primary recovery rates of nickel and cobalt. Chinese patent ZL201310332212.5 discloses a synergistic extractant and a method for selectively extracting nickel from acidic nickel-containing aqueous solutions, solving the problem of separating nickel from base metal impurities such as iron, aluminum, manganese, magnesium, calcium, and chromium. However, the synthesis process of one of its components, naphthalenesulfonic acid, is complex and costly. Chinese patents CN107815542B / CN109097599B use the acidic phosphine-type extractant P204 instead of naphthalenesulfonic acid, enabling it to operate under lower pH conditions (~2) and achieving efficient separation of nickel from impurities such as manganese, calcium, and magnesium, thus realizing industrial application. However, it still does not fundamentally solve the problem of poor acid tolerance of one of its common components, pyridine carboxylic acid ester. Summary of the Invention

[0004] To address the shortcomings of existing traditional acidic phosphine-based extractants in terms of extraction rate and selectivity, the primary objective of this invention is to provide a dithiazole tertiary amine-phosphate combination extractant, which aims to improve the extraction rate and selectivity of the target element.

[0005] The second objective of this invention is to provide a method for preparing the aforementioned dithiazole tertiary amine-phosphate combined extractant.

[0006] A third objective of this invention is to provide a method for extracting at least one ion from nickel, cobalt, and manganese using the aforementioned combined extractant.

[0007] A dithiazole tertiary amine-phosphate combination extractant includes a co-extractant and an extractant, wherein the co-extractant is at least one dithiazole tertiary amine having the structure of Formula 1, and the extractant is a phosphate ester extractant.

[0008]

[0009] Where R1 is C 6～14 The carbon chain or oxo-carbon chain; R2 is... The n1 and n2 mentioned are 0 or 1.

[0010] This invention provides a combined extractant of a compound of Formula 1 and a phosphate ester extractant, which can improve its structural stability and acid resistance, and improve the extraction effect of target elements such as nickel and cobalt, based on the special R2-N(R1)-R2 spatial binding domain constructed synergistically within the Formula 1 molecule and the intermolecular synergy between Formula 1 and the phosphate ester.

[0011] In this invention, Formula 1 and its combination with phosphate ester extractants are key to synergistically improving the nickel-cobalt extraction effect and selectivity.

[0012] In this invention, the co-extractant comprises structures of formula 1-A and / or formula 1-B;

[0013]

[0014] In this invention, in R1, the carbon chain is a saturated carbon chain; the oxocarbon chain is a carbon chain with alkoxy substituents, and may further be C 6～12 Alkyl groups;

[0015] In this invention, R2 is...

[0016] In this invention, the extractant is a compound having the structure of Formula 2;

[0017]

[0018] R3 and R4 are C individually. 6～14 alkyl or C 6～14 The alkoxy group; M is one of hydrogen ion, calcium ion, magnesium ion, ammonium ion or alkali metal ion, and n is the valence number of M.

[0019] In this invention, the molar ratio of the co-extractant and the extractant is 1 to 8:1; more specifically, it is 2 to 6:1.

[0020] The present invention also provides a co-extraction organic phase comprising the aforementioned dithiazole tertiary amine-phosphate combination extractant and diluent.

[0021] In this invention, the diluent is a conventional component capable of dissolving the extraction composition and having hydrophobic properties, such as sulfonated kerosene, No. 260 solvent oil, aviation kerosene, Escaid 110, C 8～ C 13 One or more of the higher alcohols;

[0022] In this invention, the concentration of the dithiazole tertiary amine-phosphate combined extractant in the co-extracted organic phase is above 0.5 M, more specifically 0.7–5 M, and more specifically 1–3.5 M. Further, the concentration of the dithiazole tertiary amine is 1–3 M.

[0023] The present invention also provides a method for extracting metal N ions, wherein the dithiazole tertiary amine-phosphate combined extractant is used to extract an aqueous solution containing metal N ions to obtain a loaded organic phase loaded with the metal N ions, wherein the metal N ions include at least one of nickel ions, cobalt ions, and manganese ions.

[0024] In this invention, the metal N ions include nickel ions and cobalt ions; further, manganese ions are selectively included.

[0025] This invention enables highly efficient and selective extraction of nickel-cobalt binary elements. Furthermore, when the metal N ions include nickel-cobalt-manganese ternary elements, the extraction behavior of manganese can be selectively controlled by adjusting the extraction stage conditions, such as the equilibrium pH. This facilitates the artificial control of the extraction behavior of manganese and nickel-cobalt. For example, research in this invention shows that when the equilibrium pH of the extraction stage is ≤3 (further, it can be 1–2.5), nickel-cobalt extraction can be achieved, while avoiding the co-extraction of manganese. However, when the equilibrium pH is greater than or equal to 4 (further, it can be 4.5–6.5), ternary co-extraction of nickel-cobalt-manganese can be achieved.

[0026] In this invention, the aqueous solution to be extracted is an acidic aqueous solution containing dissolved metal N ions;

[0027] In this invention, the acidic aqueous solution contains at least one of sulfate, nitrate, and chloride ions.

[0028] In this invention, the pH of the acidic aqueous solution is less than or equal to 7;

[0029] In this invention, the aqueous solution to be extracted is also permitted to contain one or more impurity ions, including calcium and magnesium ions; these impurities are enriched in the extraction residue through the extraction process. The extraction composition of this invention, in addition to exhibiting excellent extraction effect on the target metal N ions, also has low extraction activity against impurity ions, thus achieving highly selective extraction of the target ions.

[0030] In this invention, the aqueous solution to be extracted is an acid leaching solution containing metal N ions, for example, it can be a nickel-cobalt-containing acid leaching solution after iron and aluminum removal from laterite nickel ore, or an acid leaching solution for nickel-cobalt-manganese ternary cathode material.

[0031] In this invention, the aqueous solution to be extracted and the co-extraction organic phase described in this invention are mixed and contacted to obtain a supported organic phase loaded with the metal N ions.

[0032] In this invention, the O / A ratio during the extraction process is 1 / 5 to 10 / 1;

[0033] In this invention, the temperature during the extraction stage is 10–60°C;

[0034] In this invention, the extraction method is single-stage or multi-stage countercurrent extraction.

[0035] In this invention, the supported organic phase is back-extracted with acid to obtain a back-extracting solution enriched with the organic ions.

[0036] In this invention, the acid solution is H + Sulfuric acid, hydrochloric acid, or nitric acid solutions with concentrations between 0.5 and 4.0 mol / L;

[0037] In this invention, the O / A ratio of the back-extracted material is 1 / 1 to 10 / 1;

[0038] In this invention, the back-extraction temperature is 10–60°C.

[0039] Beneficial effects

[0040] The dithiazole tertiary amine-phosphate ester combined extractant provided by this invention has a significant synergistic effect on the extraction of target metal N ions in acidic solutions compared with single phosphate ester (salt) extractants, while exhibiting a significant reverse synergistic extraction effect on impurity ions such as magnesium and calcium ions. This greatly improves the selectivity for target metal N ions, thereby achieving efficient separation of target metal N ions from impurity ions such as magnesium and calcium ions.

[0041] Furthermore, in this invention, the extraction behavior of metallic Mn can be controlled as needed by adjusting the pH balance, thereby making it suitable for different application scenarios. Attached Figure Description

[0042] Figure 1 The hydrogen spectrum of formula 1-A-1;

[0043] Figure 2 The chromatogram is for formula 1-A-1; Detailed Implementation

[0044] To better understand the present invention, the present invention will be further described below through specific embodiments, but the listed embodiments do not limit the scope of protection of the present invention.

[0045] Formula 1 of the present invention can be obtained by nucleophilic substitution reaction of the secondary amine raw material of Formula 3 and the raw material of Formula 4 under the action of an acid-binding agent;

[0046]

[0047] The selection range of R1 and R2 in Equations 3 and 4 is the same as that in Equation 1, and X is a halogen.

[0048] Equation 3 can be expressed as R1-(CH2) n1 NH2 and formula 4 undergo a nucleophilic substitution reaction in the presence of an acid-binding agent to obtain the product. The nucleophilic reaction method and approach described herein can refer to the conventional nucleophilic reactions of amines and halogenated reagents.

[0049] In this invention, two-stage nucleophilic substitution reactions can be carried out in one pot. For example, formula 3 and formula 4 in a theoretical amount or more can be subjected to a one-pot two-stage affinity substitution to obtain the target extractant.

[0050] The following are typical examples of extractants:

[0051] Preparation of Formula 1-A-1 extractant

[0052] First, 4-(chloromethyl)thiazole hydrochloride (81.72 g, 0.48 mol, excess coefficient 1.2) and K₂CO₃ (60.8 g, 0.44 mol) were mixed and stirred. Then, the mixture was transferred to a 1 L round-bottom flask, and 600 mL of acetonitrile was added as a reaction solvent to promote the substitution reaction due to its high polarity. The entire reaction system was stirred, and the temperature was raised to 90 °C in an oil bath. Octylamine (26 g, 0.2 mol) was slowly added dropwise to the reaction system over 2 hours to avoid side reactions leading to the formation of a single thiazole derivative and to ensure complete substitution of octylamine. The entire reaction system was stirred and refluxed in an oil bath at 90 °C for 24 hours, followed by TCL monitoring until the reaction was complete. It is noteworthy that small amounts of deionized water should be added multiple times during the reaction to facilitate the reaction of potassium carbonate in a saturated solution, allowing the potassium chloride product to transfer to the saturated aqueous phase, thereby accelerating the reaction towards the product. At the end of the reaction, the aqueous phase saturated with potassium chloride was removed while hot using a separatory funnel, and the solvent acetonitrile in the remaining organic phase was distilled under reduced pressure at 85°C. Small amounts of mixed potassium carbonate, potassium chloride, and the reactant n-octylamine were washed away with weakly acidic water. Taking advantage of the polarity difference, small amounts of residual thiazole reactants were removed from the product with n-hexane, and n-hexane was then evaporated to give the final product. The product yield was ≥90%, and the purity was ≥95%.

[0053] In the embodiments, the distribution ratio D, separation coefficient β, synergistic coefficient R, extraction rate E1 (%), and back-extraction rate E2 (%) are calculated according to equations (1) to (5), respectively:

[0054] D = C MO / C MR (1)

[0055] βA / B=DA / DB(2)

[0056] R=D 12 / (D1+D2)(3)

[0057] E1=(C F -C R ) / C F ×100%(4)

[0058] E2 = C S / (C O ×R)×100%(5)

[0059] In equation (1), C MO C MR β represents the concentration (g / L) of metal ion M in the supported organic phase and the raffinate, respectively; in equation (2), β A / B D represents the separation coefficient between A and impurity B. A D BRepresent the distribution ratios of A and impurity B, respectively; in equation (3), D 12 The ratio of the mixed organic components to the metal is represented by D1 and D2, which are the ratios of the individual components to the metal; in equation (4), C F C R The concentrations (g / L) of metal ions in the feed solution and raffinate are respectively represented; in formula (5), C S C O The concentrations (g / L) of metal ions in the back-extraction solution and the supported organic phase are respectively, and R represents the ratio of the volumetric flow rates of the organic phase and the aqueous phase.

[0060] In this invention, P204, P507, and Cyanex272 are used by default in their non-saponifiable acid form.

[0061] Example 1

[0062] Aqueous phase: Sulfuric acid leaching solution of laterite nickel ore after hydrolysis to remove iron and aluminum (ionic composition and concentration are the same as in Table 1).

[0063] Organic phase: Organic phase A: 0.2 mol / L P2O4;

[0064] Organic phase B: 0.2 mol / L P507;

[0065] Organic phase C: 0.2 mol / L Cyanex 272;

[0066] Organic phase D: 0.5 mol / L Formula 1-A-1;

[0067] Organic phase E: 0.2 mol / L P₂O₄ + 0.5 mol / L Formula 1-A-1;

[0068] Organic phase F: 0.2 mol / L P507 + 0.5 mol / L Formula 1-A-1;

[0069] Organic phase G: 0.2 mol / L Cyanex 272+ and 0.5 mol / L Formula 1-A-1;

[0070] Organic phase H: 0.7M P2O4;

[0071] Organic phase I: 0.7M P507;

[0072] Organic phase J: 0.7 M Cyanex 272

[0073] Organic phase K: Formula 1-A-1 of 0.7 M;

[0074] Organic phase L: Comparative formula A (0.7M) The preparation method is the same as Formula 1-A-1, the only difference being that the amount of thiazole raw material is halved:

[0075] In the above organic phases, the diluent is No. 260 solvent oil.

[0076] Extraction and separation: Single-stage extraction using a separatory funnel, with a ratio of O / A = 1:1, extraction and back-extraction temperatures of 40℃, and an equilibrium pH of 2 (±0.03); extraction time of 5 min. The experimental results are as follows.

[0077] Table 1 Comparison of the effects of single acidic phosphine extractants and synergistic extraction systems

[0078]

[0079] The results showed that at pH 2 (less than or equal to 3), the addition of Formula 1-A-1 significantly enhanced the extraction rate of nickel and cobalt ions compared to single acidic phosphine extractants P204, P507, and Cyanex272. Calculations showed that in the P204 system, the synergistic coefficients of the mixed extractant for nickel and cobalt reached 81.71 and 129.10, respectively, while exhibiting significant anti-synergistic extraction effects for calcium, magnesium, and manganese ions. In the P507 system, the synergistic coefficients of the mixed extractant for nickel and cobalt reached 16.35 and 21.83, respectively. In the Cyanex272 system, the synergistic coefficients of the mixed extractant for nickel and cobalt reached 10.33 and 13.30, respectively, indicating increased separation efficiency of nickel and cobalt from other metal ions. The novel synergistic extraction system, consisting of a double chelating extractant and three acidic phosphine extractants—P204, P507, and Cyanex272—can achieve preferential extraction of nickel and cobalt, and effectively separate nickel and cobalt from manganese, calcium, and magnesium.

[0080] Example 2

[0081] Aqueous phase: Sulfuric acid leaching solution of laterite nickel ore after hydrolysis to remove iron and aluminum, Ca 2+ 0.60 g / L, Co 2+ 0.94 g / L, Mg 2+ 0.35 g / L, Mn 2+ 1.01 g / L, Ni 2+ : 0.94g / L.

[0082] Organic phases: A: a single extractant of 0.2 mol / L P204; B: 1.0 mol / L of Formula 1-A-1; C: a synergistic extraction system consisting of a combination of 0.2 mol / L P204 and 1.0 mol / L of Formula 1-A-1 extractants. The saponification rate of P204 used was 50%, and the diluent was a mixed solvent of sulfonated kerosene and isooctanol (isooctanol content was 15 v%).

[0083] Extraction and separation: single-stage extraction using a separatory funnel, with a ratio of O / A = 1:1, an extraction time of 5 min, an extraction temperature and a back-extraction temperature of 25 °C, and an extraction equilibrium pH of 1.50.

[0084] Back-extraction agent: The supported organic phase is back-extracted using 1 / 2 volume of 2.0 mol / L sulfuric acid.

[0085] Table 2. Comparison of the effects of the P204 extraction system and the synergistic extraction system

[0086]

[0087]

[0088] The results showed that, under high acid conditions (pH ≤ 3), the extraction rates of cobalt and nickel by P2O4 alone were 3.08% and 0.17%, respectively, while the extraction rates of cobalt and nickel by the mixed organic phase under the same conditions increased to 86.51% and 74.81%, respectively. On the other hand, the addition of Formula 1-A-1 significantly increased the separation coefficients of nickel and cobalt from impurities such as manganese, calcium, and magnesium ions, significantly enhancing the selectivity for nickel and cobalt ions and enabling efficient separation of nickel and cobalt from manganese, calcium, and magnesium.

[0089] Example 3

[0090] Aqueous phase: Mixed sulfates containing nickel and cobalt (content and concentration in Table 3).

[0091] Organic phase: The aqueous phase was extracted with 0.5 mol / L P507 + 3 mol / L Formula 1-A-1 combined extractant, and the diluent was sulfonated kerosene.

[0092] Extraction and separation: Single-stage extraction using a separatory funnel, with a ratio of O / A = 2:1, an extraction time of 5 min, an extraction and back-extraction temperature of 50℃, and an extraction equilibrium pH of 1.28. The extraction results are as follows.

[0093] Table 3. Extraction effect of the novel synergistic extraction system P507

[0094]

[0095] As can be seen from the table, under high acid conditions (pH ≤ 3), the synergistic system of P507 and Formula 1-A-1 can achieve efficient co-extraction of nickel and cobalt, with extraction rates of 92.04% and 88.67% for cobalt and nickel, respectively, indicating good nickel-cobalt extraction effect. At the same time, the calculated separation coefficient results show that the synergistic extraction system can achieve good separation effect of nickel and cobalt from manganese, calcium and magnesium.

[0096] Example 4

[0097] Aqueous phase: a mixed nitrate solution of nickel, manganese, calcium and magnesium metal ions (see Table 4).

[0098] Organic phase: 0.5 mol / L P204 and formula 1-A-12.0 mol / L, with No. 260 solvent oil as the diluent.

[0099] Extraction and separation: 10-stage cross-flow extraction, relative O / A = 1:1, extraction time 5 min, extraction and back-extraction temperature 50℃, equilibrium pH 1.28.

[0100] Back-extraction agent: Back-extraction was performed using 3 mol / L sulfuric acid, which constituted 1 / 4 volume of the organic phase. The experimental results are as follows.

[0101] Table 4 shows the nickel extraction effect of the 1-A-1-phosphate ester combination extractant.

[0102]

[0103] The results showed that under high acid conditions (pH ≤ 3), after 10 stages of cross-flow extraction, the nickel content in the back-extraction solution reached 42.96 g / L, while the content of other metal ions was low (< 40 ppm). Compared with the aqueous feed solution, the mass ratios of Ni / Ca, Ni / Mg, and Ni / Mn metals in the back-extraction solution increased by 1120.32, 4018.01, and 1725.12 times, respectively, indicating good separation of nickel from impurities.

[0104] Example 5

[0105] Aqueous phase: A mixed nitrate solution of cobalt, manganese, calcium, and magnesium metal ions.

[0106] Organic phase: 0.5 mol / L P507, formula 1-A-12.0 mol / L, diluent is n-decyl alcohol.

[0107] Extraction and separation: 10-stage cross-flow extraction, relative O / A = 1:1, extraction time 5 min, extraction and back-extraction temperature 20℃, equilibrium pH 1.24.

[0108] Back-extraction agent: Back-extraction was performed using 3 mol / L sulfuric acid in 1 / 4 volume of the organic phase. The experimental results are as follows.

[0109] Table 5 shows the cobalt extraction effect of the formula 1-A-1-phosphate ester combination extractant.

[0110]

[0111] The results showed that under high acid conditions (pH ≤ 3), after 10 stages of cross-flow extraction, the cobalt concentration in the back-extraction solution was 45.29 g / L, while the contents of other metal ions were low (< 30 ppm). Compared with the aqueous feed solution, the Co / Ca, Co / Mg, and Co / Mn metal mass ratios in the back-extraction solution increased by 1280.81, 6460.38, and 2391.53 times, respectively, indicating good separation of cobalt from impurity metal ions.

[0112] Example 6

[0113] Aqueous phase: The sulfuric acid leaching solution of laterite nickel ore after hydrolysis to remove iron and aluminum contains 0.26 g / L calcium, 0.57 g / L cobalt, 9.41 g / L magnesium, 1.44 g / L manganese, and 4.89 g / L nickel.

[0114] Organic phases: 0.2 mol / L P204, 0.2 mol / L P507, 0.2 mol / L C272; diluent: sulfonated kerosene. Formula 1-A-1 was added at concentrations of 0.2 mol / L and 0.4 mol / L, respectively. The diluent was the same as in Example 1.

[0115] Extraction and separation: single-stage extraction, relative O / A = 1:1, extraction time 7 min, extraction temperature 20℃, equilibrium pH 3.0.

[0116] Table 6 shows the extraction effects of Formula 1-A-1-phosphate ester combination extractants on nickel and cobalt.

[0117]

[0118] The results showed that, under high acid conditions, compared with single phosphine-type extractants such as P204, P507, and C272, it was not able to efficiently and selectively extract nickel and cobalt containing nickel, cobalt, manganese, calcium, and magnesium when used alone. However, after adding formula 1-A-1, it was able to achieve efficient synergistic extraction of nickel and cobalt and inhibit the extraction of impurity ions such as manganese, calcium, and magnesium.

[0119] Example 6

[0120] Aqueous phase: Acid leaching solution of high-magnesium laterite nickel ore after hydrolysis to remove iron and aluminum, with a pH of 1.19.

[0121] Organic phase: 0.3 mol / L P2O4 + 1.2 mol / L Formula 1-A-1 synergistic extraction system, with sulfonated kerosene and 2-octanol mixed solvent (2-octanol content 15 vol%) as diluent.

[0122] Back-extraction agent: 1 mol / L sulfuric acid; detergent: 0.2 mol / L sulfuric acid; extraction reaction time: 7 min; temperature: 30℃.

[0123] Table 7. Results of continuous extraction experiments

[0124]

[0125] Extraction and separation: Under high acid conditions, the feed solution enters from the 5th stage mixing chamber, and the extractant enters the extraction tank in reverse from the 1st stage mixing chamber. The extraction reaction occurs in the 1st to 5th stage mixing chambers, with the O / A flow rate ratio controlled at 1:1. The nickel-cobalt-rich organic phase is washed in the 6th to 8th stage mixing chambers of the washing section, with the O / A flow rate ratio at 1:4. The washed organic phase is then back-extracted in the 9th to 11th stage mixing chambers, with the O / A flow rate ratio at 1:8. A nickel sulfate and cobalt mixed solution is obtained from the outlet of the 9th stage.

[0126] Example 7

[0127] Examples 1-6 demonstrate that, under acidic conditions (pH < 3.0), the 1-A-1-phosphate ester combination extractant can achieve the extraction and separation of nickel, cobalt, manganese, calcium, magnesium, and other metals. However, for leachate from spent ternary lithium batteries, manganese, as a valuable metal, also needs to be recovered. Currently, no commercially available extraction system can achieve efficient co-extraction of nickel, cobalt, and manganese. The 1-A-1-phosphate ester can achieve this effect.

[0128] Aqueous phase: After recovering lithium from the sulfuric acid leaching solution of a waste ternary battery, it contains Ca 0.26g / L, Co 4.43g / L, Mg 0.41g / L, Mn 3.61g / L, and Ni 12.23g / L.

[0129] Organic phase: Single phosphate ester extractant (0.5 mol / L)

[0130] Phosphate ester (0.5 mol / L) + dithiazole tertiary amine (Formula 1-A-1) (1.0 mol / L) combined extractant:

[0131] The diluent was the same as in Example 6. The O / A ratio was 1:1, and extraction was performed at room temperature for 7 minutes.

[0132] The results of the extraction experiment are shown in Table 8.

[0133] Table 8. Results of nickel-cobalt-manganese co-extraction experiments using dithiazole tertiary amine (Formula 1-A-1)-phosphate combined extractant.

[0134]

[0135]

[0136] Traditional acidic phosphine-based extractants cannot achieve co-extraction of nickel, cobalt, and manganese. While they show good extraction efficiency for manganese at pH > 4.0, their selectivity for nickel and cobalt is insufficient. Experimental results show that the addition of dithiazole tertiary amine (Formula 1-A-1) significantly enhances the extraction efficiency of phosphine-based extractants for nickel and cobalt. By controlling the pH to > 4.0 during the extraction process of the dithiazole tertiary amine (Formula 1-A-1)-phosphate ester combined extractant, co-extraction of nickel, cobalt, and manganese can be achieved, enabling their separation from calcium and magnesium.

Claims

1. A dithiazole tertiary amine-phosphate combination extractant, characterized in that, It includes a co-extractant and an extractant, wherein the co-extractant is at least one dithiazole tertiary amine having the structure of Formula 1, and the extractant is a phosphate ester extractant; ； Formula 1 Where R1 is C 6~14 The carbon chain or oxo-carbon chain; R2 is... The n1 and n2 mentioned above are 0 or 1.

2. The dithiazole tertiary amine-phosphate combination extractant as described in claim 1, characterized in that, The co-extractant comprises structures of formula 1-A and / or formula 1-B; Formula 1-A; Formula 1-B.

3. The dithiazole tertiary amine-phosphate combined extractant as described in claim 2, characterized in that, In R1, the carbon chain is a saturated carbon chain; the oxocarbon chain is a carbon chain with alkoxy substituents.

4. The dithiazole tertiary amine-phosphate combination extractant as described in claim 3, characterized in that, R1 is C 6~12 Alkyl groups.

5. The dithiazole tertiary amine-phosphate combination extractant as described in claim 2, characterized in that, R2 is , or .

6. The dithiazole tertiary amine-phosphate combination extractant as described in claim 1, characterized in that, The extractant is a compound having the structure of Formula 2; Formula 2 R3 and R4 are C individually. 6~14 alkyl or C 6~14 The alkoxy group; M is one of hydrogen ion, calcium ion, magnesium ion, ammonium ion or alkali metal ion, and n is the valence number of M.

7. The dithiazole tertiary amine-phosphate combination extractant according to any one of claims 1 to 6, characterized in that, The molar ratio of the co-extractant to the extractant is 1~8:

1.

8. The dithiazole tertiary amine-phosphate combination extractant as described in claim 7, characterized in that, The molar ratio of the co-extractant to the extractant is 2~6:

1.

9. A co-extracted organic phase, characterized in that, It comprises the dithiazole tertiary amine-phosphate combination extractant and diluent as described in any one of claims 1 to 8.

10. The co-extracted organic phase as described in claim 9, characterized in that, The diluents include sulfonated kerosene, No. 260 solvent oil, aviation kerosene, Escaid 110, and C. 8~ C 13 One or more of the higher alcohols.

11. The co-extracted organic phase as described in claim 9 or 10, characterized in that, The concentration of the dithiazole tertiary amine-phosphate combination extractant is above 0.5M.

12. The co-extracted organic phase as described in claim 11, characterized in that, The concentration of the dithiazole tertiary amine-phosphate combination extractant is 0.7~5M.

13. The co-extracted organic phase as described in claim 12, characterized in that, The concentration of the dithiazole tertiary amine-phosphate combination extractant is 1~3.5M.

14. A method for extracting metal N ions, characterized in that, The aqueous solution containing metal N ions is extracted using the dithiazole tertiary amine-phosphate combined extractant according to any one of claims 1 to 8 to obtain a loaded organic phase loaded with the metal N ions, wherein the metal N ions include at least one of nickel ions, cobalt ions, and manganese ions.

15. The extraction method as described in claim 14, characterized in that, The metal N ions include nickel ions and cobalt ions.

16. The extraction method as described in claim 15, characterized in that, The metal N ions also include manganese ions.

17. The extraction method as described in claim 14, characterized in that, The aqueous solution to be extracted is an acidic aqueous solution containing dissolved metal N ions.

18. The extraction method as described in claim 17, characterized in that, The acidic aqueous solution contains at least one of sulfate, nitrate, and chloride ions.

19. The extraction method as described in claim 18, characterized in that, The pH of the acidic aqueous solution is less than or equal to 7.

20. The extraction method according to claim 14, characterized in that, The aqueous solution to be extracted also contains one or more impurities, including calcium and magnesium ions; these impurities are enriched in the extraction residue through the extraction process.

21. The extraction method as described in claim 14, characterized in that, The equilibrium pH for extraction is ≤3, or greater than or equal to 4.

22. The extraction method as described in claim 14, characterized in that, The aqueous solution to be extracted is mixed and contacted with the co-extraction organic phase according to any one of claims 9 to 13 to obtain a supported organic phase loaded with the metal N ions.

23. The extraction method as described in claim 22, characterized in that, The O / A ratio during the extraction process is 1 / 5 to 10 / 1; The temperature during the extraction stage is 10~60℃; The extraction method is single-stage or multi-stage countercurrent extraction.

24. The extraction method according to any one of claims 14 to 23, characterized in that, The supported organic phase is back-extracted using an acid solution to obtain a back-extracting solution enriched with the metal ions.

25. The extraction method as described in claim 24, characterized in that, The acid solution is H + Sulfuric acid, hydrochloric acid, or nitric acid solutions with concentrations between 0.5 and 4.0 mol / L; The O / A ratio of the back-extraction is 1 / 1 to 10 / 1; The temperature for back-extraction is 10~60℃.

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