CARBOXYLIC ACID COMPOUND, AND PREPARATION METHOD THEREFOR AND APPLICATION THEREOF

Abstract

Provided are a carboxylic acid compound of formula I, and a preparation method therefor and application thereof. When being applied to the extraction and separation of metal ions, the carboxylic acid compound can achieve a high separation coefficient, low back extraction acidity, high load rate, high back extraction rate, high stability, and low water solubility, so that the extraction process is stable, and environmental pollution and components can be reduced. The present application can be used in various systems such as ternary battery recycling and battery-grade nickel sulfate preparation.

Claims

1. A carboxylic acid compound shown in formula I or a salt thereof: ##STR00015## wherein R.sub.1 and R.sub.2 are independently selected from C.sub.3-C.sub.12 linear or branched alkyl.

2. The carboxylic acid compound shown in formula I or the salt thereof according to claim 1, wherein R.sub.1 is C.sub.4-C.sub.9 linear or branched alkyl; and/or R.sub.2 is C.sub.3-C.sub.10 linear or branched alkyl; and/or the salt of the carboxylic acid compound shown in formula I is prepared by reacting the carboxylic acid compound shown in the formula I with a base according to a molar ratio of 1:1.

3. The carboxylic acid compound shown in formula I or the salt thereof according to claim 2, wherein R.sub.1 is C.sub.4-C.sub.9 linear alkyl, for example, n-butyl, n-pentyl, n-hexyl or n-octyl; and/or R.sub.2 is C.sub.6-C.sub.9 linear or branched alkyl; for example, R.sub.2 is n-hexyl, n-octyl or isooctyl (for example, ##STR00016## and/or a total carbon number n of R.sub.1 and R.sub.2 is 10-20, and for example, n is 12, 14 or 16.

4. The carboxylic acid compound shown in formula I or the salt thereof according to claim 1, wherein the carboxylic acid compound shown in formula I is selected from any one of the following compounds: ##STR00017##

5. A preparation method for the carboxylic acid compound shown in formula I according to claim 1, comprising reacting a compound shown in formula II with a compound shown in formula III in a solvent under the action of a base; ##STR00018## wherein X is halogen, and R.sub.1 and R.sub.2 are as defined by claim 1.

6. The preparation method for the carboxylic acid compound shown in formula I according to claim 5, wherein the halogen is fluorine, chlorine, bromine or iodine, for example, chlorine or bromine, or bromine; and/or the solvent is an ether solvent, for example, tetrahydrofuran; and/or the solvent and the compound shown in formula III have a volume-mass ratio of 1-10 mL/g, for example, 5.3 mL/g, 6.25 mL/g, 7.0 mL/g, 7.1 mL/g or 7.7 mL/g; and/or the base is an alkali metal or an alkali metal hydride, for example, sodium or sodium hydride; and/or the base and the compound shown in formula II have a molar ratio of (1-1.5):1, for example, 1.1:1, 1.2:1 or 1.35:1; and/or the compound shown in formula II and the compound shown in formula III have a molar ratio of 1:(1-1.5), for example, 1:1.1 or 1:1.2; and/or the reaction has a temperature of 60-70° C.; and/or the reaction has a time of 6-12 hours, for example, 10 h.

7. An extractant, comprising the carboxylic acid compound shown in formula I or the salt thereof according to claim 1.

8. The extractant according to claim 7, wherein the extractant is one or a mixture of the carboxylic acid compounds shown in formula I; and/or the carboxylic acid compound shown in formula I or the salt thereof is used as an extractant for extracting and separating an metal ion; preferably, the metal ion is one or a mixture of Ni.sup.2+, Co.sup.2+ and Mn.sup.2+, the metal ion can further comprise one or a mixture of Fe.sup.3+, Al.sup.3+, Cu.sup.2+, Zn.sup.2+, Cd.sup.2+ and Ca.sup.2+, and the metal ion can further comprise Mg.sup.2+ and/or Li.sup.+.

9. The extractant according to claim 8, wherein the extractant is selected from any one or a mixture of the following compounds: ##STR00019## and/or when the carboxylic acid compound shown in formula I or the salt thereof is used as an extractant for extracting and separating an metal ion, the metal ion is a combination of at least one of Ni.sup.2+, Co.sup.2+ and Mn.sup.2+ with at least one of Fe.sup.3+, Al.sup.3+, Cu2+, Zn.sup.2+, Cd.sup.2+, Ca.sup.2+, Mg.sup.2+ and Li.sup.+; preferably, the metal ion is a mixture of Ni.sup.2+, Co.sup.2+, Mn.sup.2+, Fe.sup.3+, Al.sup.3+, Cu.sup.2+, Zn.sup.2+, Cd.sup.2+, Ca.sup.2+, Mg.sup.2+ and Li.sup.+.

10. An extraction composition, comprising an extractant and a diluent, wherein the extractant comprises the carboxylic acid compound shown in formula I according to claim 1 and/or the salt of the carboxylic acid compound shown in formula I according to claim 1.

11. The extraction composition according to claim 10, wherein the carboxylic acid compound shown in formula I and the salt of the carboxylic acid compound shown in formula I have a molar ratio of (0.4-9):1, for example, 1:1; preferably, the extractant comprises the carboxylic acid compound shown in formula I and the salt of the carboxylic acid compound shown in formula I, and more preferably, the carboxylic acid compound shown in formula I and the salt of the carboxylic acid compound shown in formula I have a molar ratio of (0.4-9):1; and/or the diluent is one or a mixture of solvent oil (for example, 200 # solvent oil or 260 # solvent oil), kerosene, Escaid 110, hexane, heptane and dodecane (for example, n-dodecane); preferably, the diluent is one or a mixture of solvent oil (for example, 260 # solvent oil), dodecane (for example, n-dodecane) and Escaid 110; and/or the extractant and the diluent have a molar-volume ratio of 0.1-1.5 mol/L, preferably 0.16-0.85 mol/L, for example, 0.16 mol/L, 0.33 mol/L or 0.6 mol/L.

12. An extraction method, comprising extracting an aqueous phase containing a metal ion with an organic phase containing an extractant to obtain an organic phase containing a metal ion; in the organic phase containing an extractant, the extractant comprises the carboxylic acid compound shown in formula I according to claim 1 and/or the salt of the carboxylic acid compound shown in formula I according to claim 1; in the aqueous phase containing a metal ion, the metal ion comprises one or a mixture of Ni.sup.2+, Co.sup.2+, Mn.sup.2+, Fe.sup.3+, Al.sup.3+, Cu.sup.2+, Zn.sup.2+, Cd.sup.2+ and Ca.sup.2+.

13. The extraction method according to claim 12, wherein the metal ion is a combination of at least one of Ni.sup.2+, Co.sup.2+ and Mn.sup.2+ with at least one of Fe.sup.3+, Al.sup.3+, Cu.sup.2+, Zn.sup.2+, Cd.sup.2+, Ca.sup.2+, Mg.sup.2+, and Li.sup.+; preferably, the metal ion is a mixture of Ni.sup.2+, Co.sup.2+, Mn.sup.2+, Fe.sup.3+, Al.sup.3+, Cu.sup.2+, Zn.sup.2+, Cd.sup.2+, Ca.sup.2+, Mg.sup.2+ and Li.sup.+; and/or in the organic phase containing an extractant, the carboxylic acid compound shown in formula I and the salt of the carboxylic acid compound shown in formula I have a molar ratio of (0.4-9):1, for example, 1:1; preferably, the extractant comprises the carboxylic acid compound shown in formula I and the salt of the carboxylic acid compound shown in formula I; more preferably, the carboxylic acid compound shown in formula I and the salt of the carboxylic acid compound shown in formula I have a molar ratio of (0.4-9):1; and/or the organic phase containing an extractant further comprises a diluent, wherein the diluent is one or a mixture of solvent oil (for example, 200 # solvent oil or 260 # solvent oil), kerosene, Escaid 110, hexane, heptane and dodecane (for example, n-dodecane); preferably, the diluent is one or a mixture of solvent oil (for example, 260 # solvent oil), dodecane (for example, n-dodecane) and Escaid 110; the extractant and the diluent have a molar-volume ratio of 0.1-1.5 mol/L, preferably 0.16-0.85 mol/L, for example, 0.16 mol/L, 0.33 mol/L or 0.6 mol/L; and/or the organic phase containing an extractant and the aqueous phase containing a metal ion have a volume ratio of 1:(1-10), preferably 1:(1-5), for example, 1:1, 1:2 or 1:4; and/or mass transfer is realized by shaking in the extraction method; and/or the extraction has a temperature of 10-50° C., preferably 25-40° C.; and/or the extraction has a time of 5-60 minutes, for example, 15 minutes or 30 minutes.

14. A back extraction method, comprising mixing the organic phase containing a metal ion obtained from the extraction method according to claim 12 with an acid aqueous solution.

15. The back extraction method according to claim 14, wherein the acid aqueous solution has a molar concentration of 0.5-5 mol/L, preferably 1-3 mol/L, for example, 1 mol/L or 2 mol/L; and/or an acid in the acid aqueous solution is an inorganic acid, and the inorganic acid is preferably one or more of hydrochloric acid, sulfuric acid, phosphoric acid and nitric acid, more preferably sulfuric acid; and/or the organic phase containing a metal ion and the acid aqueous solution have a volume ratio of (1-50):1, more preferably (10-20):1, for example, 10:1 or 15:1.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0059] FIG. 1 shows extraction rate E%-pH curves of Compound BC196 for each ion.

DETAILED DESCRIPTION

[0060] The present application is further illustrated by the embodiments, but the present application is not limited by the embodiments. The experimental methods without specific conditions in the embodiments are selected from the conventional methods and conditions, or the product specifications.

[0061] The information about experiments in the embodiments is as follows.

[0062] The organic phase refers to an organic phase containing an extractant and a diluent, in which the extractant includes the carboxylic acid compound shown in formula I and the salt of the carboxylic acid compound shown in formula I.

[0063] The aqueous phase refers to an aqueous phase containing metal ions, wherein the aqueous phase containing metal ions can be prepared by the conventional methods, which, for example, include the following steps: dissolving a certain amount of a salt in deionized water and diluting the solution to a required concentration.

[0064] The ratio (O:A) refers to a volume ratio of an organic phase to an aqueous phase.

[0065] The term “saponification” refers to the replacement of a hydrogen ion in the extractant by an alkali metal ion and/or NH.sub.4.sup.+ (the obtained alkali metal ion and/or NH.sub.4.sup.+ can be exchanged with metal ions to be extracted in the aqueous phase to achieve extraction); the saponification includes the step: mixing the organic phase with the base aqueous solution. Preferably, the base aqueous solution used in the saponification can be an aqueous solution of sodium hydroxide, an aqueous solution of potassium hydroxide or ammonia.

[0066] The saponification proportion refers to the proportion of the alkali metal and/or NH.sub.4.sup.+ to the original hydrogen ion, i.e.,

η=(V.sub.base×C.sub.base)/(V.sub.org+C.sub.org)   (1).

[0067] In equation (1), V.sub.base the volume of the base aqueous solution added, C.sub.base is the concentration of the base aqueous solution added, V.sub.org is the volume of the organic phase, and C.sub.org is the extractant concentration of the organic phase.

[0068] In the embodiments of the present application, the metal ion concentration of the aqueous phase is determined by the inductively coupled plasma optical emission spectroscopy (ICP-OES), and the metal ion concentration of the organic phase is calculated by the difference subtraction method.

[0069] Potentiometric titration for acid content, with reference to the literature: Yuan Chengye, Hu Shuisheng; Studies on Organophosphorus Compounds XVI. Substituent Constants σ.sup.p for Long Chain Alkyl and Alkoxyl Groups and their Correlation with Group Connectivity [J]. Acta Chimica Sinica, 1986, 44, 590-596; potentiometric titrator: Metrohm 907 Titrando, Switzerland. The acid content is used to represent the extractant purity in the embodiments of the present application.

[0070] The distribution ratio D is a ratio of the metal ion content of the equilibrium organic phase to the metal ion content of the equilibrium aqueous phase after the first extraction (the metal ion concentration of the equilibrium aqueous phase is determined by the inductively coupled plasma optical emission spectroscopy (ICP-OES), and the metal ion concentration of the equilibrium organic phase is calculated by the difference subtraction method), i.e.,

D=C.sub.org/C.sub.aq=(C′.sub.aq−C.sub.aq)/C.sub.aq   (2)

[0071] In equation (2), C.sub.org represents the metal ion concentration of the equilibrium organic phase after the first extraction; C.sub.aq represents the metal ion concentration of the equilibrium aqueous phase after the first extraction; C′.sub.aq represents the metal ion concentration of the aqueous phase before the first extraction.

[0072] The extraction rate E is the percentage of the amount of the extracted substance transferred to organic phase from aqueous phase during the extraction process against the total amount of the extracted substances in the original aqueous phase, i.e.,

E=100%×(C′.sub.aq−C.sub.aq)/C′.sub.aq   (3)

[0073] In equation (3), C.sub.aq represents the metal ion concentration of the equilibrium aqueous phase after the first extraction; C′.sub.aq represents the metal ion concentration of the aqueous phase before the first extraction.

[0074] The separation coefficient β refers to a ratio of the distribution ratios of two substances to be separated in two phases under certain conditions, which is also known as extraction separation factor.

[0075] Raw materials for which no preparation method is provided in the embodiments are commercially available.

EXAMPLE 1

[0076] ##STR00006##

[0077] 50 g of isooctanol, 225 mL of tetrahydrofuran (THF) and 8.8 g of sodium granules were added into a three-necked flask, and reacted at 60-70° C. for 6 h; a large amount of white solid was generated and a small amount of sodium granules remained; at 60° C., 40 mL of THF solution containing 8 mol/L 2-bromooctanoic acid was added dropwise, and then reacted at 60° C. for 4 h; after cooling, THF was removed by rotary evaporation, and then 200 mL of water and 200 mL of ethyl acetate (EA) were added into the concentrated solution, shaken and allowed to form layer separation, and the aqueous layer was collected; the aqueous layer was acidified with hydrochloric acid to a pH of about 1 and extracted with ethyl acetate, and then the organic phase was washed with water twice and dried by rotary evaporation, so as to obtain 65 g of light yellow product, i.e., Compound BC195. .sup.1H NMR (400 MHz, CDCl.sub.3) δ 4.1 (1H), 3.52 (1H), 3.35 (1H), 1.82 (2H), 1.54 (3H), 1.20-1.31 (14H), 0.91 (6H), 0.87 (3H); .sup.13C NMR (101 MHz, CDCl.sub.3) δ 171 (s), 79 (s), 72 (s), 36(s), 32 (s), 29 (s), 26-28 (m), 22-23 (m), 14 (s), 11 (s); MS [M-H].sup.−: 271.

EXAMPLE 2

[0078] ##STR00007##

[0079] 28.6 g of isooctanol, 200 mL of tetrahydrofuran (THF) and 8.8 g of 60% sodium hydride (dispersed in mineral oil) were added into a three-necked flask, and reacted at 60-70° C. for 6 h; a large amount of white solid was generated and a small amount of sodium granules remained; at 60° C., 20 mL of THF solution containing 10 mol/L 2-bromohexanoic acid was added dropwise, and then reacted at 60° C. for 4 h; after cooling, THF was removed by rotary evaporation, and then 200 mL of water and 200 mL of ethyl acetate (EA) were added into the concentrated solution, shaken and allowed to form layer separation, and the aqueous layer was collected; the aqueous layer was acidified with hydrochloric acid to a pH of about 1 and extracted with ethyl acetate, and then the organic phase was washed with water twice and dried by rotary evaporation, so as to obtain 38 g of light yellow product, i.e., Compound BC196. .sup.1H NMR (400 MHz, CDCl.sub.3) δ 3.97 (1H), 3.41 (1H), 3.26 (1H), 1.70 (2H), 1.45 (3H), 1.05-1.24 (10H), 0.91 (9H); .sup.13C NMR (101 MHz, CDCl.sub.3) δ 175 (s), 82 (s), 76 (s), 40 (s), 32 (s), 30 (s), 29 (s), 27 (s), 22-23 (m), 14 (s), 11 (s); MS[M-H].sup.−: 243.

EXAMPLE 3

[0080] ##STR00008##

[0081] 32 g of n-octanol, 200 mL of tetrahydrofuran (THF) and 5.7 g of sodium granules were added into a three-necked flask, and reacted at 60-70° C. for 6 h; a large amount of white solid was generated and a small amount of sodium granules remained; at 60° C., 20 mL of THF solution containing 10 mol/L 2-bromohexanoic acid was added dropwise, and then reacted at 60° C. for 4 h; after cooling, THF was removed by rotary evaporation, and then 200 mL of water and 200 mL of ethyl acetate (EA) were added into the concentrated solution, shaken and allowed to form layer separation, and the aqueous layer was collected; the aqueous layer was acidified with hydrochloric acid to a pH of about 1 and extracted with ethyl acetate, and then the organic phase was washed with water twice and dried by rotary evaporation, so as to obtain the target compound, i.e., Compound BC191.

[0082] Compound BC191 .sup.1H NMR (400 MHz, CDCl.sub.3) δ 12.53 (1H), 4.01 (1H), 3.32 (2H), 1.65 (2H), 1.20-1.32 (16H), 0.89 (6H); .sup.13C NMR (101 MHz, CDCl.sub.3) δ 173 (s), 81(s), 65 (s), 32-30 (m), 22-23 (m), 14 (s); MS[M-H].sup.−: 243.

EXAMPLE 4

[0083] ##STR00009##

[0084] 32 g of n-octanol, 200 mL of tetrahydrofuran (THF) and 5.7 g of sodium granules were added into a three-necked flask, and reacted at 60-70° C. for 6 h; a large amount of white solid was generated and a small amount of sodium granules remained; at 60° C., 22 mL of THF solution containing 10 mol/L 2-bromooctanoic acid was added dropwise, and then reacted at 60° C. for 4 h; after cooling, THF was removed by rotary evaporation, and then 200 mL of water and 200 mL of ethyl acetate (EA) were added into the concentrated solution, shaken and allowed to form layer separation, and the aqueous layer was collected; the aqueous layer was acidified with hydrochloric acid to a pH of about 1 and extracted with ethyl acetate, and then the organic phase was washed with water twice and dried by rotary evaporation, so as to obtain the target compound, i.e., Compound BC192.

[0085] Compound BC192 tH NMR (400 MHz, CDCl.sub.3) δ 11.54 (1H), 3.98 (1H), 3.30 (2H), 1.63 (2H), 1.42-1.44 (4H), 1.20-1.32 (16H), 0.89 (6H); MS[M-H].sup.−: 271.

EXAMPLE 5

[0086] ##STR00010##

[0087] 28 g of n-hexanol, 200 mL of tetrahydrofuran (THF) and 6.4 g of sodium granules were added into a three-necked flask, and reacted at 60-70° C. for 6 h; a large amount of white solid was generated and a small amount of sodium granules remained; at 60° C., 20 mL of THF solution containing 10 mol/L 2-bromohexanoic acid was added dropwise, and then reacted at 60° C. for 4 h; after cooling, THF was removed by rotary evaporation, and then 200 mL of water and 200 mL of ethyl acetate (EA) were added into the concentrated solution, shaken and allowed to form layer separation, and the aqueous layer was collected; the aqueous layer was acidified with hydrochloric acid to a pH of about 1 and extracted with ethyl acetate, and then the organic phase was washed with water twice and dried by rotary evaporation, so as to obtain the target compound, i.e., Compound BC193.

[0088] Compound BC193 .sup.1H NMR (400 MHz, CDCl.sub.3) δ 12.34 (1H), 3.89 (1H), 3.29 (2H), 1.61 (2H), 1.20-1.32 (10H), 0.89 (6H); MS[M-H].sup.−: 215.

EXAMPLE 6

[0089] ##STR00011##

[0090] 28 g of n-hexanol, 200 mL of tetrahydrofuran (THF) and 6.4 g of sodium granules were added into a three-necked flask, and reacted at 60-70° C. for 6 h; a large amount of white solid was generated and a small amount of sodium granules remained; at 60° C., 22 mL of THF solution containing 10 mol/L 2-bromooctanoic acid was added dropwise, and then reacted at 60° C. for 4 h; after cooling, THF was removed by rotary evaporation, and then 200 mL of water and 200 mL of ethyl acetate (EA) were added into the concentrated solution, shaken and allowed to form layer separation, and the aqueous layer was collected; the aqueous layer was acidified with hydrochloric acid to a pH of about 1 and extracted with ethyl acetate, and then the organic phase was washed with water twice and dried by rotary evaporation, so as to obtain the target compound, i.e., Compound BC194.

[0091] Compound BC194 .sup.1H NMR (400 MHz, CDCl.sub.3) δ 12.86 (1H), 4.04 (1H), 3.37 (2H), 1.67 (2H), 1.42-1.44 (8H), 1.20-1.32 (8H), 0.89 (6H); MS[M-H].sup.−: 215.

Performance Example 1 Extraction performance of Compound BC196

[0092] Compound BC196 has a structure:

##STR00012##

[0093] (an acid content is 98%) (the acid content refers to the extractant purity).

[0094] Compound BC196 was dissolved in a diluent, 260 # solvent oil, and prepared as a 0.6 mol/L organic phase, and a mixed sulfate solution was prepared as an aqueous phase, which contained 0.02 mol/L Cu.sup.2+, Zn.sup.2+, Fe.sup.3+, Al.sup.3+, Cd.sup.2+, Ni.sup.2+, Co.sup.2+, Mn.sup.2+, Ca.sup.2+, Mg.sup.2+ and Li.sup.+. The organic phase was firstly saponified by 11.9 mol/L sodium hydroxide aqueous solution with a saponification rate of 0-70%, the initial pH of the aqueous phase remained unchanged at 2.08, and the aqueous phase was extracted by the organic phase with different saponification degree at a volume ratio of 1:1, the equilibrium time was 15 min and the temperature was 25° C.

[0095] After extraction, the extraction rate and equilibrium pH were plotted to obtain the extraction rate E%-pH curve of Compound BC196 for each ion. The results are shown in FIG. 1 and Table 1. The separation coefficient of Compound BC196 between various ions is shown in Table 2.

TABLE-US-00001 TABLE 1 Extraction rate E % of Compound BC196 for each ion Equilibrium Extraction Rate E % pH Fe.sup.3+ Cu.sup.2+ Ca.sup.2+ Al.sup.3+ Cd.sup.2+ Zn.sup.2+ Ni.sup.2+ Co.sup.2+ Mn.sup.2+ Mg.sup.2+ Li.sup.+ 4.5 90.2 95.0 71.5 26.3 76.0 62.0 42.5 34.5 27.5 1.6 2.3

TABLE-US-00002 TABLE 2 Separation Coefficient of Compound BC196 between various ions Separation Coefficient β Cu.sup.2+ Ca.sup.2+ Al.sup.3+ Cd.sup.2+ Zn.sup.2+ Ni.sup.2+ Co.sup.2+ Mn.sup.2+ Mg.sup.2+ Ca.sup.2+ 7.57 Al.sup.3+ 53.22 7.03 Cd.sup.2+ 6.00 0.79 0.11 Zn.sup.2+ 11.64 1.54 0.22 1.94 Ni.sup.2+ 25.71 3.40 0.48 4.29 2.21 Co.sup.2+ 36.05 4.76 0.68 6.01 3.10 1.40 Mn.sup.2+ 50.13 6.62 0.94 8.36 4.31 1.95 1.39 Mg.sup.2+ 1165.64 153.93 21.90 194.29 100.12 45.34 32.33 23.25 Li.sup.+ 808.51 106.77 15.19 134.77 69.447 31.45 22.43 16.13 0.69

[0096] It can be seen from FIG. 1 and Table 1 that the extraction sequence of Compound BC196 goes: Fe.sup.2+, Cu.sup.2+, Ca.sup.2+, Al.sup.2+, Cd.sup.2+, Zn.sup.2+, Ni.sup.2+, Co.sup.2+, Mn.sup.2+, Mg.sup.2+ and Li.sup.2+; when the equilibrium pH value is 4.5, the extraction rate of Compound BC196 for Zn is about 65%, the extraction rate for Ni, Co and Mn is 25-45%, and Mg can hardly be extracted. It can be seen from Table 2 that the separation coefficients of Zn for Ni, Co, Mn are 2.21, 3.10 and 4.31 respectively, and the separation coefficients of Ni, Co, Mn for Mg are 45.34, 32.33 and 23.25 respectively. It can be seen that Compound BC196 extracts nickel, cobalt and manganese before magnesium ions, and nickel, cobalt and manganese have high separation degree from impurity metal ions such as magnesium and zinc. The above results show that, compared with the reported extractants P204, P507 and C272, Compound BC196 has better ion selectivity, which can synchronously recycle nickel, cobalt and manganese, and has feasible application value in the recovery of positive electrode materials of lithium-ion batteries.

Performance Comparative Example 1

[0097] This comparative example differs from Performance Example 1 in that Compound BC196 was replaced by Extractant CA12 (commercially available, with an acid content of 98%). The results are shown in Table 3.

TABLE-US-00003 TABLE 3 Separation coefficients of Compounds BC196 and CA12 for each ion Metal ion System pH β.sub.Ni/Co β.sub.Ni/Mn β.sub.Ni/Mg β.sub.Ni/Zn Compound BC196 4.5 1.40 1.95 45.34 2.21 CA12 4.5 1.08 1.41 31.98 1.66

[0098] As can be seen from Table 3 that the separation coefficients of Compound BC196 for each ion are higher by about 20-30% compared with CA12 under the same test condition. Under the pH condition of about 4.5, the separation coefficients of Compound BC196 for Ni/Mg and Ni/Zn are 45.34 and 2.21, respectively, while the separation coefficients of CA12 for Ni/Mg and Ni/Zn are 31.98 and 1.66, respectively, which indicates that Compound BC196 has better ion separation performance than CA12.

Performance Example 2 Back Extraction Performance of Compound BC196 Loaded with Metal Ions

[0099] Compound BC196 was dissolved in dodecane and prepared as a 0.33 mol/L organic phase, and the aqueous phase used a 0.02 mol/L Ni.sup.2+ sulfate solution to be a feed solution. The organic 20 phase was saponified with 9 mol/L ammonia, the saponification proportion was 50%, the saponified organic phase extracted the feed solution with a phase ratio of 1:4, the equilibrium time was 15 min and the temperature was 25° C. The organic phase loaded with Ni was obtained, which had a Ni content of 0.08 mol/L.

[0100] The organic phase loaded with Ni was back-extracted with 1 mol/L sulfuric acid aqueous solution, and during the back extraction, the phase ratio was 10:1, and the back extraction rate was more than 99%.

[0101] However, the P507 organic phase loaded with Ni is generally back-extracted with 2 mol/L sulfuric acid, and the first back extraction rate is about 85%. The above results show that when the carboxylic acid compound of the present application is applied to the extraction of metal ions, a higher back extraction rate can be obtained on the premise of lower back extraction acidity.

Performance Example 3 Saturation Capacity of Compound BC196 for Ni.SUP.2+

[0102] Test Method: Compound BC196 was dissolved in dodecane and prepared as a 0.6 mol/L organic phase. A 50 g/L NiSO.sub.4 aqueous solution was prepared as an aqueous phase.

[0103] 10 mL of the organic phase was added into a 50 mL separatory funnel, and saponified to a proportion of 60% with 10 mol/L NaOH aqueous solution, and with no need to wait the saponified organic phase to separate layers, 10 mL of aqueous phase was added directly, shaken and mixed for 15 min; the aqueous phase was separated, and then a fresh 50 g/L NiSO4 aqueous phase (10 mL) was added, shaken and mixed for 15 min; the above operation was repeatedly carried out until the ion concentration in the aqueous phase did not change, and then the metal concentration of the organic phase was the saturation capacity of the extractant. The organic phase was back-extracted and the saturation capacity of Compound BC196 for Ni.sup.2+ was obtained to be 16 g/L.

Performance Example 4 Back Extraction Performance of Compound BC195 Loaded with Metal Ions

[0104] Compound BC195 has a structure:

##STR00013##

(an acid content is 95%).

[0105] Compound BC195 was dissolved in Escaid 110 and prepared as a 0.16 mol/L organic phase, and a 0.02 mol/L Ni.sup.2+ sulfate solution was prepared as a feed liquid. The organic phase was saponified to a proportion of 50% with 10 mol/L NaOH aqueous solution, and the saponified organic phase extracted the feed solution with a phase ratio of 1:2, the equilibrium time was 15 min and the temperature was 25° C. The organic phase loaded with Ni was obtained, which had a Ni content of 0.04 mol/L.

[0106] The organic phase loaded with Ni was back-extracted with 1 mol/L sulfuric acid aqueous solution, and during the back extraction, the phase ratio was 15:1, and the back extraction rate was more than 99%.

[0107] However, the P507 organic phase loaded with Ni is generally back-extracted with 2 mol/L sulfuric acid, and the first back extraction rate is about 85%. The above results show that when the carboxylic acid compound of the present application is applied to the extraction of metal ions, a higher back extraction rate can be obtained on the premise of lower back extraction acidity.

Performance Example 5 Solubility Test of Extractant BC199 and Extractant CA12 in Extraction Systems

[0108] Extractant BC199 is obtained by mixing the following compounds with a molar ratio of 1:1:1:1:

##STR00014##

(an acid content is 99%).

[0109] Extraction: Extractant BC199 and diluent Escaid 110 were prepared to a 0.6 mol/L solution as an organic phase, each compound has a concentration of 0.15 mol/L in the organic phase, and an aqueous phase was a 0.2 mol/L NiSO.sub.4 aqueous solution; 100 mL of the organic phase was added into a 250 mL separatory funnel, and 10 mol/L sodium hydroxide aqueous solution was added for saponification to a proportion of 24%, 100 mL of the aqueous phase was added, extraction equilibrium was carried out for 30 min, and the temperature was 25° C.

[0110] Oil content test: 50 mL of the aqueous phase reaching equilibrium was added into a 100 mL separatory funnel, and then added with a proper amount of HCl to adjust the pH value of the aqueous phase less than or equal to 2. The 25 mL of tetrafluoroethylene was accurately transferred into the separatory funnel with a pipette, shaken for 10 min and then allowed to stand. The tetrachloroethylene in the lower part of the separatory funnel was discharged into a conical flask, then anhydrous sodium sulfate was added into the conical flask to about 1 g/L and shaken, and the sodium sulfate should not agglomerate to ensure that the water in tetrachloroethylene was removed completely. With tetrachloroethylene as a blank group, the oil content in the sample was determined by infrared oil meter.

Performance Comparative Example 2

[0111] This comparative example differs from Performance Example 5 in that Compound BC199 was replaced by Extractant CA12 (commercially available, with an acid content of 98%). The solubility of Extractant CA12 in the extraction system was tested.

[0112] The test results of Performance Example 5 and Performance Comparative Example 2 are shown in Table 4.

TABLE-US-00004 TABLE 4 Solubility of Extractant BC199 and CA12 in extraction systems Extractant Blank CA12 BC199 Diluent Equilibrium pH of the System 8.09 8.20 — Organic Compound Content mg/L 6000 120 45

[0113] Through the above tests, it can be seen that the oil content extracted after the blank diluent (with no extractant added, and other operations were the same as Performance Example 5) reached equilibrium with the water phase is 45 mg/L, the oil content extracted after Extractant BC199 reached extraction equilibrium at pH 8.20 is about 120 mg/L, and the oil content extracted after CA12 reached extraction equilibrium at pH 8.09 is about 6000 mg/L. The results show that CA12 has a large dissolution loss in the extraction system, which causes an unstable process operation, and Extractant BC199 solves the problem of large extractant solubility in aqueous phase when used for extraction and separation of metal ions, which greatly reduces the process cost and ensures stable process operation.

Performance Example 6

[0114] Compound BC195 and diluent Escaid 110 were prepared into a 0.62 mol/L solution, and an aqueous phase was a magnesium-enriched nickel chloride solution containing 1.33 g/L Ni and 4 g/L Mg; 100 mL of the organic phase was added in a 250 mL separatory funnel, 10 mol/L sodium hydroxide aqueous solution was added for saponification to a saponification proportion of 24%, and after the saponification, 100 mL of the aqueous phase was added, extraction equilibrium was carried out for 30 min, and the temperature was 25° C.

[0115] Oil content test: the aqueous phase was separated out and added with H.sub.2SO.sub.4, and the [H.sup.+] concentration of the aqueous phase solution was about 1 mol/L. The CH.sub.2Cl.sub.2 was used for extraction (30 mL×3), and the CH.sub.2Cl.sub.2 layer was collected, dried with 1 g anhydrous Na.sub.2SO.sub.4 to remove the water in CH.sub.2Cl.sub.2, and filtered; the filtrate was subjected to rotary evaporation, and then the residue was dried with an oil pump for 30 min. The oil content which CH.sub.2Cl.sub.2 extracted out in the system was obtained by weighing the flask before and after the rotary evaporation.

Performance Comparative Example 3

[0116] This comparative example differs from Performance Example 6 in that Compound BC195 was replaced by Extractant CA12 (commercially available, with an acid content of 98%).

[0117] The test results of Performance Example 6 and Performance Comparative Example 3 are shown in Table 5.

TABLE-US-00005 TABLE 5 Solubility of Compound BC195 and Compound CA12 in extraction systems Compound Blank CA12 BC195 Diluent Equilibrium pH 7.15 7.23 — Organic Compound Content mg/L 4180 75 45

[0118] Through the above tests, it can be seen that the oil content extracted after the blank diluent (with no extractant added, and other operations were the same as Performance Example 6) reached equilibrium with the water phase is 45 mg/L, the oil content extracted after Compound BC195 reached extraction equilibrium at pH 7.2 is about 75 mg/L, and the oil content for CA12 is about 4180 mg/L. CA12 has a large dissolution loss in the extraction system. Compound BC195 solves the problem of large extractant solubility in aqueous phase when used for extraction and separation of metal ions, which ensures stable process operation and reduces the process cost.