Extracting agent for extracting and separating nickel cobalt and lithium magnesium and application thereof

Abstract

The invention discloses an extracting agent for extracting and separating nickel cobalt and lithium magnesium, which relates to the technical field of extracting agents and is a composite extracting agent consisting of an extracting agent A and a synergistic extracting agent B, the extraction agent A is tertiary carbon carboxylic acid and salt thereof, the synergistic extraction agent B is composed of a synergistic extraction agent a and a synergistic extraction agent b, the synergistic extraction agent a is naphthalene sulfonic acid and salt thereof, and the synergistic extraction agent b is alcohol R5OH. The invention provides a synergistic extraction system of nickel and cobalt. Tertiary-carbon carboxylic acid with the carbon atom number of 10-20, tertiary-carbon sulfonic acid with the carbon atom number of 10-20 and fatty alcohol with the carbon atom number of 8-16 cooperate with each other. The tertiary carbon carboxylic acid, the tertiary carbon sulfonic acid and the fatty alcohol are matched, so that the tertiary carbon carboxylic acid, the tertiary carbon sulfonic acid and the fatty alcohol have very good selectivity and relatively strong extraction capacity on nickel ions and cobalt ions; and the defects that the water solubility of an existing extraction system is high and strong acid enters a water phase when the strong acid is used for reverse extraction are effectively overcome.

Description

Technical Field

[0001] The invention relates to the technical field of extractants, and in particular to an extractant for extracting and separating nickel, cobalt, lithium and magnesium and an application thereof. Background Art

[0002] Nickel and cobalt are two important metal elements that are widely used in many industrial fields. Nickel is mainly used to manufacture stainless steel, alloy materials, batteries and other products, while cobalt is mainly used to manufacture batteries, alloys, magnetic materials and the like. However, nickel and cobalt often coexist with impurity elements such as Li, Mg, and CaMn during the recycling of primary or secondary resources, and the extraction of Ni and Co requires the separation of these impurity elements. Organic phosphoric acid is a commonly used extractant that can form complexes with metals such as nickel and cobalt, has good selectivity, and the chemical properties of organic phosphoric acid extractants are stable, not easy to decompose and fail, and can maintain the extraction effect for a long time. Common organic phosphoric acids include dibutyl phosphoric acid (D2EHPA), tributyl phosphate (TBP), etc. However, organic phosphoric acid has a high cost, and some harmful substances may be produced during the extraction agent treatment process, which has a certain impact on the environment.

[0003] CN115433832A discloses a nickel and cobalt synergistic extractant and its use, wherein the extractant comprises a long-chain monobasic fatty acid having more than 12 carbon atoms and a nitrogen-containing heterocyclic compound having more than 9 branched carbon atoms, wherein the long-chain monobasic fatty acid has a branched chain on the β-carbon or α-carbon. The synergistic extraction system can efficiently extract nickel and cobalt, and at the same time has a good removal effect on the common coexisting impurity ions of manganese, magnesium, and calcium, and overcomes the defects of large water solubility and difficult phase separation of traditional extractants. The extraction system composed of the extractant can be used to extract nickel and cobalt from nickel laterite leaching solution, extract nickel and cobalt from secondary ternary battery waste leaching solution, extract nickel from electroplating waste liquid, and extract nickel and cobalt from other nickel- and cobalt-containing feed solutions. The application of the extractant can simplify the process, improve the yield and purity of nickel and cobalt, reduce the consumption of acid and alkali reagents, and can greatly reduce the cost of nickel and cobalt extraction. However, the extraction system needs to use high-concentration sulfuric acid during stripping, resulting in high acid consumption, long extraction process, and strong acid stripping agent easily enters the water phase.

[0004] CN116356142A discloses a bipyridine-based extractant, a preparation method thereof, and an application thereof as a nickel-cobalt extractant. The bipyridine-based extractant has the following structure: wherein R is an alkyl group of C12 to C25; the preparation method thereof is to obtain the bipyridine-based extractant by reacting chloromethylpyridine hydrochloride with a primary amine compound through a bimolecular nucleophilic substitution reaction. The bipyridine-based extractant has stable physical and chemical properties, large saturation capacity, good oil solubility of the extractant, and good coordination and complexing ability for nickel (cobalt) ions. The bipyridine-based extractant can be combined with DNNSA or P204 to form a synergistic extraction system to selectively extract and separate nickel and cobalt in a complex metal ion solution system, and can also be used as a single extraction system to efficiently extract and separate nickel and cobalt in a hydrochloric acid system, and has good industrial application prospects. However, this type of catalyst also has a strong extraction ability for Ca and Mg. Therefore, the selectivity of the extraction system for extracting Ni and Co and separating Mg is also poor, making it difficult to apply in practice.

[0005] Therefore, developing new methods that can efficiently separate Ni, Co and other metal ion impurities and achieving efficient separation of Ni and Co are issues that need to be addressed urgently. Summary of the invention

[0006] The invention provides an extractant for extracting and separating nickel, cobalt, lithium and magnesium and application thereof, so as to solve the problem that the existing method cannot realize efficient separation of Ni, Co and other metal ion impurities.

[0007] In order to solve the above technical problems, the technical solution of the present invention is:

[0008] An extractant for extracting and separating nickel, cobalt, lithium and magnesium, which is a composite extractant composed of an extractant A and a synergistic extractant B;

[0009] The extractant A is a tertiary carbon carboxylic acid and its salt, and the structural formula is as follows:

[0010]

[0011] The synergistic extractant B is composed of synergistic extractant a and synergistic extractant b, wherein the synergistic extractant a is naphthalenesulfonic acid and its salt, and the structural formula is as follows:

[0012]

[0013] The co-extractant b is alcohol R5OH;

[0014] Wherein, R1 and R2 are straight or branched fatty chains with 5-10 carbon atoms respectively; the number of branches can be one or more. If there are multiple branches, the total number of carbon atoms of the multiple branches must be 5-10.

[0015] R3 and R4 are straight or branched fatty chains with 1-5 carbon atoms respectively; the number of branches can be one or more. If there are multiple branches, the total number of carbon atoms of the multiple branches must be 1-5.

[0016] R5 is a straight or branched fatty chain having 8 to 16 carbon atoms. The number of branches can be one or more. If there are multiple branches, the total number of carbon atoms of the multiple branches must be between 8 and 16.

[0017] Among them, the extractant A is a tertiary carboxylic acid and its salt. Because the tertiary carboxylic acid has an active α carbon atom and a strong active site, the reaction efficiency is high. Moreover, because it has a large steric hindrance, it overcomes the disadvantage of ordinary carboxylic acid extractants that they are easily soluble in water.

[0018] Among them, synergistic extractant a has a special large bond structure and is coupled with tert-carbonic acid. Through strong steric hindrance, the efficiency of separation of nickel-cobalt and lithium-magnesium is increased. In addition, synergistic extractant b has surface active properties and its hydrophobicity is coupled with tert-carbonic acid, further compensating for the deficiency of extractant A being slightly soluble in water.

[0019] Therefore, the extraction of nickel and cobalt by the extractant of the present invention effectively solves the problems of high water solubility of the extraction system, difficult phase separation, poor separation effect of impurity ions, etc. The synergistic extractant can be applied to the actual industrial production of Ni and Co, and can efficiently extract and separate nickel and cobalt, while having a good removal and separation effect on common coexisting impurity ions such as lithium, magnesium, iron, aluminum, calcium, manganese and chromium.

[0020] In addition, the extractant in the present invention can refer to one of nickel or cobalt, or can extract nickel and cobalt at the same time, and when nickel and cobalt are extracted at the same time, both nickel and cobalt have good extraction and separation effects.

[0021] Wherein, the molar ratio of the extractant A to the co-extractant B is 5:(1-2).

[0022] Wherein, the molar ratio of the synergistic extractant a to the synergistic extractant b in the synergistic extractant is 5:1 to 1:5.

[0023] Wherein, the extractant A is at least one of 2-methyl-2-pentylheptanoic acid, 2-methyl-2-pentylnonanoic acid, 2-hexyl-2-methyloctanoic acid, 2-hexyl-2-methylnonanoic acid, 2-heptyl-2-methylnonanoic acid, 2-heptyl-2-methyldecanoic acid, 2-(2,2-dimethylpropyl)-2,3,4-trimethylpentanoic acid, 2-(2,2-dimethylpropyl)-2,3,3-trimethylpentanoic acid, and 2-(2,2-dimethylpropyl)-2,3,3,4-tetramethylpentanoic acid or its salt.

[0024] Wherein, the co-extractant a is at least one of 3,6-dipropylnaphthalene-1-sulfonic acid, 3,6-dibutylnaphthalene-1-sulfonic acid, 3,6-dipentylnaphthalene-1-sulfonic acid, 6-ethyl-3-propylnaphthalene-1-sulfonic acid, 6-(prop-2-yl)-3-propylnaphthalene-1-sulfonic acid, 6-(prop-2-yl)-3-butylnaphthalene-1-sulfonic acid, and 3-(2-methylpropyl)-6-(prop-2-yl)naphthalene-1-sulfonic acid.

[0025] Wherein, the synergistic extractant b is at least one of 2-ethyloctan-1-ol, 4-methyloctan-1-ol, 2-propyloctan-1-ol, 1-decanol, isoundecan-1-ol, 12-methyltridecane-1-ol, 4-pentadecanol, 2-pentadecanol, pentadecan-8-ol and hexadecanol.

[0026] The invention also provides the application of the extractant, which is used for extracting nickel and / or cobalt from a solution containing nickel and / or cobalt, and can separate the impurity elements lithium, magnesium, iron, aluminum, calcium, manganese and chromium.

[0027] Among them, the solution containing nickel and / or cobalt includes nickel laterite leaching solution, secondary ternary battery waste leaching solution or electroplating waste liquid or nickel sulfide ore leaching solution; in the present invention, the solution containing nickel and / or cobalt is not limited to this, and can also be other slurry containing nickel and / or cobalt.

[0028] The extractant of the present invention is used to separate and recover nickel and cobalt in a nickel-cobalt-magnesium-lithium solution. The method is to use the extractant of the present invention as an organic phase, mix it with a solution containing nickel and / or cobalt after adjusting the pH (the pH value is adjusted to 3-4.5), extract, obtain a loaded organic phase containing nickel and cobalt and a raffinate containing trace amounts of lithium and magnesium, and after multi-stage extraction, the separation efficiency is: nickel is greater than 95%, cobalt is greater than 99%, lithium is less than 5%, and magnesium is less than 5%.

[0029] The organic phase containing nickel-cobalt synergistic extractant uses kerosene as diluent, and the concentration of extractant A of nickel-cobalt synergistic extractant in the organic phase is 0.1-0.2 mol / L. During the extraction process, the pH of the solution containing nickel and / or cobalt is controlled at 3-4.5, O / A is 3:1-1:3, and the phase separation time is 2-5 minutes.

[0030] Compared with the prior art, the technical solution provided by the present invention has the following beneficial effects:

[0031] The present invention provides a synergistic extraction system of nickel and cobalt, which is coordinated by tertiary carbon carboxylic acid with carbon number of 10-20, tertiary carbon sulfonic acid with carbon number of 10-20 and fatty alcohol with carbon number of 8-16. The tertiary carbon carboxylic acid, tertiary carbon sulfonic acid and fatty alcohol have good selectivity and strong extraction ability for nickel ions and cobalt ions, and effectively solve the defects of the existing extraction system that the water solubility is large and the strong acid enters the water phase due to the use of strong acid for stripping.

[0032] The extraction process of the present invention is carried out at room temperature, and the phase separation performance is good during the extraction process, the oil-water interface is clear, the phase separation time is short, and effective separation of nickel, cobalt and other impurity elements such as lithium, magnesium, iron, aluminum, calcium, manganese and chromium can be achieved. DETAILED DESCRIPTION

[0033] The following embodiments are provided for a better understanding of the present invention, but are not limited to the best mode of implementation, and do not limit the content and protection scope of the present invention. Any product identical or similar to the present invention obtained under the inspiration of the present invention or by combining the features of the present invention with other prior arts shall fall within the protection scope of the present invention.

[0034] Example 1

[0035] This embodiment provides an extractant for extracting and separating nickel, cobalt, and lithium and magnesium, which is a composite extractant composed of an extractant A and a synergist B; wherein the extractant A is 2-methyl-2-pentylheptanoic acid, the synergist B is composed of 3,6-dipropylnaphthalene-1-sulfonic acid and 2-ethyloctane-1-ol in a molar ratio of 2:1, and the molar ratio of the extractant A to the synergist B is 5:1.5.

[0036] Extraction operation:

[0037] The leaching solution of laterite nickel ore after precipitation and impurity removal is used for standby use. The composition of the leaching solution is 3.26g / L Ni 2+ , 0.36g / LCo 2+ , 1.78 g / L Mn 2+ , 0.54 g / L Ca 2+ , 1.26 g / L Li + , 18g / L Mg 2+ ,.

[0038] At room temperature, the extractant was mixed with diluent kerosene to obtain a synergistic extractant with an extractant A concentration of 0.15 mol / L. The leachate of the laterite nickel ore after precipitation and impurity removal was adjusted to pH 4 and then mixed with the synergistic extractant for extraction, with an O / A ratio of 2:1 and a phase separation time of 4 min. A loaded organic phase containing nickel and cobalt and a raffinate containing trace amounts of lithium and magnesium were obtained. After three-stage extraction, the separation efficiency was: 95.9% for nickel, 99.2% for cobalt, 3.4% for lithium, and 2.3% for magnesium.

[0039] Example 2

[0040] This embodiment provides an extractant for extracting and separating nickel, cobalt, lithium and magnesium, which is a composite extractant composed of an extractant A and a synergist B; wherein the extractant A is 2-methyl-2-pentylnonanoic acid, the synergist B is composed of 3,6-dibutylnaphthalene-1-sulfonic acid and 4-methyloctan-1-ol in a molar ratio of 5:1, and the molar ratio of the extractant A to the synergist B is 5:1.

[0041] Extraction operation:

[0042] The leaching solution of laterite nickel ore after precipitation and impurity removal is used for standby use. The composition of the leaching solution is 3.26g / L Ni 2+ , 0.36g / LCo 2+ , 1.78 g / L Mn 2+ , 0.54 g / L Ca 2+ , 1.26 g / L Li + , 18g / L Mg 2+ .

[0043] At room temperature, the extractant is mixed with the diluent kerosene to obtain a synergistic extractant with an extractant A concentration of 0.1 mol / L. The leachate of the laterite nickel ore after precipitation and impurity removal is adjusted to pH 4.5 and mixed with the synergistic extractant for extraction. The O / A ratio is 3:1 and the phase separation time is 5 min. The loaded organic phase containing nickel and cobalt and the raffinate containing trace amounts of lithium and magnesium are obtained. After three-stage extraction, the separation efficiency is: nickel is 96.2%, cobalt is 99.5%, lithium is 3.1%, and magnesium is 2.6%.

[0044] Example 3

[0045] This embodiment provides an extractant for extracting and separating nickel, cobalt, lithium and magnesium, which is a composite extractant composed of an extractant A and a synergist B; wherein the extractant A is 2-hexyl-2-methyloctanoic acid, the synergist B is composed of 3,6-dipentylnaphthalene-1-sulfonic acid and 2-propyloctane-1-ol in a molar ratio of 5:2, and the molar ratio of the extractant A to the synergist B is 1:5.

[0046] Extraction operation:

[0047] The leaching solution of laterite nickel ore after precipitation and impurity removal is used for standby use. The composition of the leaching solution is 3.26g / L Ni 2+ , 0.36g / LCo 2+ , 1.78 g / L Mn 2+ , 0.54 g / L Ca 2+ , 1.26 g / L Li + , 18g / L Mg 2+ .

[0048] Under room temperature, the extractant is mixed with diluent kerosene to obtain a synergistic extractant with an extractant A concentration of 0.2 mol / L. The leachate of the laterite nickel ore after precipitation and impurity removal is adjusted to pH 3 and mixed with the synergistic extractant for extraction. The O / A ratio is 1:3 and the phase separation time is 2 min. The loaded organic phase containing nickel and cobalt and the raffinate containing trace amounts of lithium and magnesium are obtained. After three-stage extraction, the separation efficiency is: nickel is 96.15%, cobalt is 99.2%, lithium is 2.6%, and magnesium is 3.2%.

[0049] Example 4

[0050] This embodiment provides an extractant for extracting and separating nickel, cobalt, lithium and magnesium, which is a composite extractant composed of an extractant A and a synergist B; wherein the extractant A is 2-hexyl-2-methylnonanoic acid, the synergist B is composed of 6-ethyl-3-propylnaphthalene-1-sulfonic acid and 1-decanol in a molar ratio of 5:1, and the molar ratio of the extractant A to the synergist B is 1:3.

[0051] Extraction operation:

[0052] Take the sulfuric acid leaching solution of NCM battery for use. The composition of the leaching solution is 20.12g / L Ni 2+ , 13.78g / L Co 2+ , 14.26 g / L Mn 2+ , 0.56 g / L Ca 2+ , 0.86g / L Li + , 0.78 g / L Mg 2+ .

[0053] At room temperature, the extractant is mixed with the diluent kerosene to obtain a synergistic extractant with an extractant A concentration of 0.12 mol / L. The leachate of the laterite nickel ore after precipitation and impurity removal is adjusted to pH 3.5 and mixed with the synergistic extractant for extraction. The O / A ratio is 1:1 and the phase separation time is 3 minutes. The loaded organic phase containing nickel and cobalt and the raffinate containing trace amounts of lithium and magnesium are obtained. After three-stage extraction, the separation efficiency is: nickel is 97.1%, cobalt is 99.4%, lithium is 2.4%, and magnesium is 3.0%.

[0054] Example 5

[0055] This embodiment provides an extractant for extracting and separating nickel, cobalt, and lithium and magnesium, which is a composite extractant composed of an extractant A and a synergist B; wherein the extractant A is 2-heptyl-2-methylnonanoic acid, the synergist B is composed of 6-(propan-2-yl)-3-propylnaphthalene-1-sulfonic acid and isoundecane-1-ol in a molar ratio of 5:2, and the molar ratio of the extractant A to the synergist B is 3:1.

[0056] Extraction operation:

[0057] Take the sulfuric acid leaching solution of NCM battery for use. The composition of the leaching solution is 20.12g / L Ni 2+ , 13.78g / L Co 2+ , 14.26 g / L Mn 2+ , 0.56 g / L Ca 2+ , 0.86g / L Li + , 0.78 g / L Mg 2+ .

[0058] At room temperature, the extractant is mixed with the diluent kerosene to obtain a synergistic extractant with an extractant A concentration of 0.18 mol / L. The leachate of the laterite nickel ore after precipitation and impurity removal is adjusted to pH 4.2 and mixed with the synergistic extractant for extraction. The O / A ratio is 1:2 and the phase separation time is 3 min. The loaded organic phase containing nickel and cobalt and the raffinate containing trace amounts of lithium and magnesium are obtained. After three-stage extraction, the separation efficiency is: nickel is 95.9%, cobalt is 99.7%, lithium is 2.1%, and magnesium is 2.9%.

[0059] Example 6

[0060] This embodiment provides an extractant for extracting and separating nickel, cobalt, and lithium and magnesium, which is a composite extractant composed of an extractant A and a synergist B; wherein the extractant A is 2-heptyl-2-methyldecanoic acid, the synergist B is composed of 6-(propan-2-yl)-3-butylnaphthalene-1-sulfonic acid and 12-methyltridecane-1-ol in a molar ratio of 5:2, and the molar ratio of the extractant A to the synergist B is 4:1.

[0061] Extraction operation:

[0062] Take the sulfuric acid leaching solution of NCM battery for use. The composition of the leaching solution is 20.12g / L Ni 2+ , 13.78g / L Co 2+ , 14.26 g / L Mn 2+ , 0.56 g / L Ca 2+ , 0.86g / L Li + , 0.78 g / L Mg 2+ .

[0063] At room temperature, the extractant is mixed with the diluent kerosene to obtain a synergistic extractant with an extractant A concentration of 0.16 mol / L. The leachate of the laterite nickel ore after precipitation and impurity removal is adjusted to pH 3.8 and mixed with the synergistic extractant for extraction. The O / A ratio is 1:2 and the phase separation time is 3 min. The loaded organic phase containing nickel and cobalt and the raffinate containing trace amounts of lithium and magnesium are obtained. After three-stage extraction, the separation efficiency is: nickel is 96.2%, cobalt is 99.5%, lithium is 2.3%, and magnesium is 2.8%.

[0064] Example 7

[0065] This embodiment provides an extractant for extracting and separating nickel, cobalt, and lithium and magnesium, which is a composite extractant composed of an extractant A and a synergist B; wherein the extractant A is 2-(2,2-dimethylpropyl)-2,3,4-trimethylpentanoic acid, the synergist B is composed of 3-(2-methylpropyl)-6-(prop-2-yl)naphthalene-1-sulfonic acid and 4-pentadecanol in a molar ratio of 5:1, and the molar ratio of the extractant A to the synergist B is 1:2.

[0066] Extraction operation:

[0067] Take the nickel sulfide ore wastewater for use. The nickel-containing wastewater composition is 0.35g / L Ni 2+ , 0.12g / L Co 2+ , 1.22g / LLi + , 1.36 g / L Mg 2+ .

[0068] The leaching solution of laterite nickel ore after precipitation and impurity removal is used for standby use. The composition of the leaching solution is 3.26g / L Ni 2+ , 0.36g / LCo 2+ , 1.78 g / L Mn 2+ , 0.54 g / L Ca 2+ , 18g / L Mg 2+ .

[0069] At room temperature, the extractant is mixed with the diluent kerosene to obtain a synergistic extractant with an extractant A concentration of 0.15 mol / L. The leachate of the laterite nickel ore after precipitation and impurity removal is adjusted to pH 4.1 and mixed with the synergistic extractant for extraction. The O / A ratio is 1:2 and the phase separation time is 4 minutes. The loaded organic phase containing nickel and cobalt and the raffinate containing trace amounts of lithium and magnesium are obtained. After three-stage extraction, the separation efficiency is: nickel is 96.4%, cobalt is 99.5%, lithium is 2.1%, and magnesium is 2.4%.

[0070] Example 8

[0071] This embodiment provides an extractant for extracting and separating nickel, cobalt, lithium and magnesium, which is a composite extractant composed of an extractant A and a synergist B; wherein the extractant A is 2-(2,2-dimethylpropyl)-2,3,3-trimethylpentanoic acid, the synergist B is composed of 3,6-dibutylnaphthalene-1-sulfonic acid and hexadecanol in a molar ratio of 5:1, and the molar ratio of the extractant A to the synergist B is 1:4.

[0072] Extraction operation:

[0073] Take the nickel sulfide ore wastewater for use. The nickel-containing wastewater composition is 0.35g / L Ni2+ , 0.12g / L Co 2+ , 1.22g / LLi + , 1.36 g / L Mg 2+ .

[0074] At room temperature, the extractant was mixed with the diluent kerosene to obtain a synergistic extractant with an extractant A concentration of 0.14 mol / L. The leachate of the laterite nickel ore after precipitation and impurity removal was adjusted to pH 4 and mixed with the synergistic extractant for extraction. The O / A ratio was 3:2 and the phase separation time was 4 min. The loaded organic phase containing nickel and cobalt and the raffinate containing trace amounts of lithium and magnesium were obtained. After three-stage extraction, the separation efficiency was: 96.3% for nickel, 99.6% for cobalt, 2.9% for lithium and 3.2% for magnesium.

[0075] Example 9

[0076] This embodiment provides an extractant for extracting and separating nickel, cobalt, and lithium and magnesium, which is a composite extractant composed of an extractant A and a synergist B; wherein the extractant A is 2-(2,2-dimethylpropyl)-2,3,3,4-tetramethylpentanoic acid, the synergist B is composed of 3,6-dibutylnaphthalene-1-sulfonic acid and pentadecane-8-ol in a molar ratio of 5:1, and the molar ratio of the extractant A to the synergist B is 1:4.

[0077] Extraction operation:

[0078] Take the nickel sulfide ore wastewater for use. The nickel-containing wastewater composition is 0.35g / L Ni 2+ , 0.12g / L Co 2+ , 1.22g / LLi + , 1.36 g / L Mg 2+ .

[0079] At room temperature, the extractant was mixed with the diluent kerosene to obtain a synergistic extractant with an extractant A concentration of 0.15 mol / L. The leachate of the laterite nickel ore after precipitation and impurity removal was adjusted to pH 4.2 and mixed with the synergistic extractant for extraction. The O / A ratio was 1:3 and the phase separation time was 3 min. The loaded organic phase containing nickel and cobalt and the raffinate containing trace amounts of lithium and magnesium were obtained. After three-stage extraction, the separation efficiency was: 96.5% for nickel, 99.2% for cobalt, 2.3% for lithium and 2.8% for magnesium.

[0080] Comparative Example 1

[0081] This embodiment provides an extractant for extracting and separating nickel, cobalt, lithium and magnesium. The extractant is 2-methyl-2-pentylheptanoic acid.

[0082] Extraction operation:

[0083] The leaching solution of laterite nickel ore after precipitation and impurity removal is used for standby use. The composition of the leaching solution is 3.26g / L Ni 2+ , 0.36g / LCo 2+ , 1.78 g / L Mn 2+ , 0.54 g / L Ca 2+ , 1.26g / L Li + , 18g / L Mg 2+ ,.

[0084] At room temperature, the extractant was mixed with diluent kerosene to obtain a synergistic extractant with an extractant A concentration of 0.15 mol / L. The leachate of the laterite nickel ore after precipitation and impurity removal was adjusted to pH 4 and then mixed with the synergistic extractant for extraction, with an O / A ratio of 2:1 and a phase separation time of 4 min. A loaded organic phase containing nickel and cobalt and a raffinate containing trace amounts of lithium and magnesium were obtained. After three-stage extraction, the separation efficiency was: 46.8% for nickel, 49.2% for cobalt, 6.9% for lithium, and 6.2% for magnesium.

[0085] Comparative Example 2

[0086] This embodiment provides an extractant for extracting and separating nickel, cobalt, and lithium and magnesium, which is a composite extractant composed of an extractant A and a synergist B; wherein the extractant A is 2-methyl-2-pentylheptanoic acid, the synergist B is 3,6-dipropylnaphthalene-1-sulfonic acid, and the molar ratio of the extractant A to the synergist B is 5:1.5.

[0087] Extraction operation:

[0088] The leaching solution of laterite nickel ore after precipitation and impurity removal is used for standby use. The composition of the leaching solution is 3.26g / L Ni 2+ , 0.36g / LCo 2+ , 1.78 g / L Mn 2+ , 0.54 g / L Ca 2+ , 1.26g / L Li + , 18g / L Mg 2+ ,.

[0089] At room temperature, the extractant was mixed with diluent kerosene to obtain a synergistic extractant with an extractant A concentration of 0.15 mol / L. The leachate of the laterite nickel ore after precipitation and impurity removal was adjusted to pH 4 and then mixed with the synergistic extractant for extraction, with an O / A ratio of 2:1 and a phase separation time of 4 min. A loaded organic phase containing nickel and cobalt and a raffinate containing trace amounts of lithium and magnesium were obtained. After three-stage extraction, the separation efficiency was: 49.8% for nickel, 51.2% for cobalt, 5.4% for lithium, and 6.3% for magnesium.

[0090] Comparative Example 3

[0091] This embodiment provides an extractant for extracting and separating nickel, cobalt, and lithium and magnesium, which is a composite extractant composed of an extractant A and a synergist B; wherein the extractant A is 2-methyl-2-pentylheptanoic acid, the synergist B is 2-ethyloctan-1-ol, and the molar ratio of the extractant A to the synergist B is 5:1.5.

[0092] Extraction operation:

[0093] The leaching solution of laterite nickel ore after precipitation and impurity removal is used for standby use. The composition of the leaching solution is 3.26g / L Ni 2+ , 0.36g / LCo 2+ , 1.78 g / L Mn 2+ , 0.54 g / L Ca 2+ , 1.26g / L Li + , 18g / L Mg 2+ ,.

[0094] At room temperature, the extractant was mixed with diluent kerosene to obtain a synergistic extractant with an extractant A concentration of 0.15 mol / L. The leachate of the laterite nickel ore after precipitation and impurity removal was adjusted to pH 4 and then mixed with the synergistic extractant for extraction, with an O / A ratio of 2:1 and a phase separation time of 4 min. A loaded organic phase containing nickel and cobalt and a raffinate containing trace amounts of lithium and magnesium were obtained. After three-stage extraction, the separation efficiency was: 55.9% for nickel, 59.2% for cobalt, 6.4% for lithium, and 6.3% for magnesium.

[0095] Although the embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and cannot be understood as limiting the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention without departing from the principles and purpose of the present invention. The protection scope of the present invention is defined by the claims and their equivalent technical solutions.

Claims

1. An extractant for extracting and separating nickel, cobalt, lithium and magnesium, characterized in that: It is a composite extractant composed of extractant A and synergistic extractant B; The extractant A is a tertiary carbon carboxylic acid and its salt, and the structural formula is as follows: The synergistic extractant B is composed of synergistic extractant a and synergistic extractant b, wherein the synergistic extractant a is naphthalenesulfonic acid and its salt, and the structural formula is as follows: The co-extractant b is alcohol R5OH; Wherein, R1 and R2 are straight or branched aliphatic chains with 5 to 10 carbon atoms; R3 and R4 are straight or branched aliphatic chains with 1 to 5 carbon atoms; R5 is a straight or branched aliphatic chain having 8 to 16 carbon atoms.

2. The extractant for extracting and separating nickel, cobalt, lithium and magnesium according to claim 1, characterized in that: The molar ratio of the extractant A to the co-extractant B is 5:(1-2).

3. The extractant for extracting and separating nickel, cobalt, lithium and magnesium according to claim 1, characterized in that: The molar ratio of the synergistic extractant a to the synergistic extractant b in the synergistic extractant is 5:1 to 1:

5.

4. The extractant for extracting and separating nickel, cobalt, lithium and magnesium according to claim 1, characterized in that: The extractant A is at least one of 2-methyl-2-pentylheptanoic acid, 2-methyl-2-pentylnonanoic acid, 2-hexyl-2-methyloctanoic acid, 2-hexyl-2-methylnonanoic acid, 2-heptyl-2-methylnonanoic acid, 2-heptyl-2-methyldecanoic acid, 2-(2,2-dimethylpropyl)-2,3,4-trimethylpentanoic acid, 2-(2,2-dimethylpropyl)-2,3,3-trimethylpentanoic acid, and 2-(2,2-dimethylpropyl)-2,3,3,4-tetramethylpentanoic acid or a salt thereof.

5. The extractant for extracting and separating nickel, cobalt, lithium and magnesium according to claim 1, characterized in that: The co-extractant a is at least one of 3,6-dipropylnaphthalene-1-sulfonic acid, 3,6-dibutylnaphthalene-1-sulfonic acid, 3,6-dipentylnaphthalene-1-sulfonic acid, 6-ethyl-3-propylnaphthalene-1-sulfonic acid, 6-(prop-2-yl)-3-propylnaphthalene-1-sulfonic acid, 6-(prop-2-yl)-3-butylnaphthalene-1-sulfonic acid, and 3-(2-methylpropyl)-6-(prop-2-yl)naphthalene-1-sulfonic acid.

6. The extractant for extracting and separating nickel, cobalt, lithium and magnesium according to claim 1, characterized in that: The synergist b is at least one of 2-ethyloctan-1-ol, 4-methyloctan-1-ol, 2-propyloctan-1-ol, 1-decanol, isoundecan-1-ol, 12-methyltridecane-1-ol, 4-pentadecanol, 2-pentadecanol, pentadecan-8-ol and hexadecanol.

7. Use of the extractant according to any one of claims 1 to 6, characterized in that: It is used to extract nickel and / or cobalt from solutions containing nickel and / or cobalt, and can separate impurity elements such as lithium, magnesium, iron, aluminum, calcium, manganese and chromium.

8. The use of the extractant according to claim 7, characterized in that: The solution containing nickel and / or cobalt includes nickel laterite leaching solution, secondary ternary battery waste leaching solution or electroplating waste solution or nickel sulfide ore leaching solution.

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