阅读说明：本技术 一种分离镍和镁的方法及其应用 (Method for separating nickel and magnesium and application thereof ) 是由 王雪 于 2020-11-24 设计创作，主要内容包括：本发明提供一种分离镍和镁的方法及其应用,所述分离方法包括如下步骤：(1)将高纯萃取剂和稀释剂配置成一定体积分数的萃取有机相,随后萃取有机相与碱性化合物进行皂化反应,得到皂化有机相；所述萃取剂中包含特定的羧酸类化合物BC197；(2)采用步骤(1)得到的皂化有机相对镍镁料液进行混合、萃取、分层,得到负载有机相和萃余水相；(3)用反萃剂对步骤(2)得到的负载有机相进行反萃取,得到金属离子富集溶液和再生有机相；整个分离过程操作简便、酸耗低、对环境友好；所述分离方法对镍和镁分离效果好,分离系数高,反萃酸度低,而且所用的萃取试剂水溶性低,稳定,再生后可循环使用,有利于降低分离成本,适合大批量应用。(The invention provides a method for separating nickel and magnesium and application thereof, wherein the separation method comprises the following steps: (1) preparing a high-purity extracting agent and a diluting agent into an extracted organic phase with a certain volume fraction, and then performing saponification reaction on the extracted organic phase and an alkaline compound to obtain a saponified organic phase; the extractant comprises a specific carboxylic acid compound BC 197; (2) mixing, extracting and layering the saponified organic phase-to-nickel-magnesium feed liquid obtained in the step (1) to obtain a loaded organic phase and an extracted water phase; (3) carrying out back extraction on the loaded organic phase obtained in the step (2) by using a back extractant to obtain a metal ion enriched solution and a regenerated organic phase; the whole separation process is simple and convenient to operate, low in acid consumption and environment-friendly; the separation method has good nickel and magnesium separation effect, high separation coefficient and low back extraction acidity, and the used extraction reagent has low water solubility and stability, can be recycled after regeneration, is favorable for reducing the separation cost, and is suitable for large-scale application.)

1. A method for separating nickel and magnesium and application thereof are characterized in that the separation method comprises the following steps:

(1) preparing a high-purity extracting agent and a diluting agent into an extracted organic phase with a certain volume fraction, and then performing saponification reaction on the extracted organic phase and an alkaline compound to obtain a saponified organic phase;

the high-purity extractant is a carboxylic acid compound BC197 with the structure shown in the formula I:

wherein, C₈H₁₇Is a straight or branched chain alkane group;

(2) mixing the saponified organic phase obtained in the step (1) with a nickel-magnesium feed liquid, extracting, clarifying and splitting phases to obtain a loaded organic phase and an extracted water phase; the loaded organic phase contains metallic nickel ions;

(3) carrying out back extraction on the loaded organic phase obtained in the step (2) by using a back extractant to obtain a metal ion enriched solution and a regenerated organic phase; the metal ion-enriched solution contains nickel ions.

2. The separation method according to claim 1, wherein the high-purity extractant accounts for 5-30% of the volume of the extracted organic phase;

preferably, the diluent of the high-purity extractant comprises any one of or a combination of at least two of Escaid110, solvent naphtha, toluene, hexane, heptane, dodecane or kerosene; more preferably Escaid110 and/or dodecane.

3. The separation process of any one of claims 1 to 2, wherein the basic compound of step (1) comprises an inorganic base;

preferably, the inorganic base comprises any one of sodium hydroxide, magnesium oxide, potassium hydroxide or ammonia water or a combination of at least two of the foregoing.

4. The separation method according to any one of claims 1 to 3, wherein the volume ratio of the saponified organic phase to the nickel-magnesium feed liquid in the step (2) is 1 (0.1 to 10);

preferably, the equilibrium pH value of the raffinate water phase in the step (2) is 5.0-7.8;

preferably, the mixing of step (2) is carried out under stirring conditions;

preferably, the stirring speed is 100-800 rpm/min;

preferably, the mixing time is 5-30 min;

preferably, the extraction method in the step (2) is multi-stage countercurrent fractional extraction;

preferably, the extraction stages of the multistage countercurrent fractional extraction are 2-18 stages;

preferably, the extraction in the step (2) is carried out at the temperature of 10-50 ℃;

preferably, the time for clarifying and layering in the step (2) is 2-30 min;

preferably, the nickel-magnesium system in the step (2) is a chloride system or a sulfate system, and a further preferred nickel-magnesium system is a sulfate system;

preferably, the nickel-magnesium ratio of the nickel-magnesium system in the step (2) is 1 (0.5-20);

preferably, the reaction equipment in the step (2) is a mixer-settler, a packed extraction tower, a spray extraction tower, and more preferably the reaction equipment is a mixer-settler.

5. The separation process according to any one of claims 1 to 4, wherein the stripping agent comprises an inorganic acid;

preferably, the inorganic acid comprises any one of hydrochloric acid, nitric acid or sulfuric acid or a combination of at least two thereof;

preferably, the concentration of the inorganic acid in the stripping agent is 0.5-4 mol/L, and further preferably, the concentration of the stripping agent is 2 mol/L.

6. The separation method according to any one of claims 1 to 5, wherein the number of stages of the back extraction in the step (3) is 1 to 10;

preferably, the volume ratio of the stripping agent to the loaded organic phase is 1 (0.1-10);

preferably, the back extraction also comprises a step of washing the loaded organic phase obtained in the step (2);

preferably, the washing stages are 2-16 stages;

preferably, the washing comprises washing with mineral acid and/or acidified water, nickel sulfate solution;

preferably, the pH value of the inorganic acid and/or the acidified water is 0.1-2;

preferably, the nickel sulfate solution is 0.5-20 g/L.

7. The separation method according to any one of claims 1 to 6, characterized in that the separation method comprises in particular the steps of:

(1) carrying out saponification reaction on the extracted organic phase and an alkaline compound to obtain a saponified organic phase with a saponification degree of 1-50%; the extracted organic phase comprises a diluent and a carboxylic acid compound BC197 with the structure shown in the formula I:

wherein, C₈H₁₇Is a straight or branched chain alkane group;

(2) mixing the saponified organic phase obtained in the step (1) with a nickel-magnesium feed liquid with a pH value of 2-8 according to a volume ratio of 1 (0.1-10), extracting, clarifying and phase-splitting to obtain a loaded organic phase containing nickel ions and an extracted water phase containing magnesium ions with a pH value of 5.0-7.8;

(3) washing the loaded organic phase obtained in the step (2) by using a detergent, and then back-extracting by using a back-extractant to obtain a metal ion enriched solution containing nickel ions and a regenerated organic phase; the volume ratio of the stripping agent to the loaded organic phase is 1 (0.1-10), and the regenerated organic phase can be recycled.

8. Use of the separation method according to any one of claims 1 to 7 for separating nickel and magnesium from a battery nickel cobalt manganese metal recovery system;

preferably, the battery is a ternary nickel cobalt manganese battery.

9. The application of an extraction reagent containing carboxylic acid compounds with the structure shown in the formula I in separation of nickel and magnesium.

Technical Field

The invention belongs to the technical field of metal ion separation and purification, and particularly relates to a method for separating nickel and magnesium and application thereof.

Background

At present, a new energy battery is widely applied to the fields of automobiles, energy storage, electronic equipment and the like, compared with fossil energy, the new energy battery can effectively reduce carbon emission, particularly the field of power batteries, along with the application and development of metals such as nickel and the like in the power batteries, the utilization technology of nickel metal needs to be improved to be suitable for the development of the application of the nickel metal, the nickel metal element is used as a necessary metal material for producing the power batteries, part of the nickel metal element is from laterite nickel ore and nickel sulfide ore, and part of the nickel metal element is from the recovery of waste lithium batteries. Meanwhile, heavy metals such as nickel, cobalt, manganese and the like contained in the waste batteries have serious harm to the environment, so that the precious metals contained in the waste lithium batteries are recycled, resources can be recycled, the environment can be protected, and the environment-friendly lithium battery has better environment and market prospects.

The main methods for recovering noble metals such as nickel and the like from waste lithium ion batteries are an active method metallurgy method and a wet method metallurgy method. The application of pyrometallurgy is limited due to the problems of poor operating conditions, high operating temperature, high energy consumption, serious air pollution, complex driving and parking and the like; the hydrometallurgy method can be directly made into products, has the characteristics of low cost, high automation and the like, and has optimistic application prospect. The hydrometallurgical methods mainly include chemical precipitation, membrane separation, ion exchange, adsorption, and solvent extraction.

CN102814058A discloses a method for separating, enriching and purifying nickel and magnesium by using an adsorption material experiment, wherein a solution to be treated containing nickel ions and magnesium ions is adjusted to pH value of 1.0-5.5 to obtain a pickle liquor, the pickle liquor is contacted and mixed with a heavy metal adsorption material of an adsorption column, the heavy metal adsorption material can adsorb the nickel ions in the pickle liquor, the magnesium ions are remained in the pickle liquor, and the heavy metal adsorption material is washed by 5-30% sulfuric acid solution to carry out desorption operation to obtain a nickel-containing desorption liquor and an analyzed heavy metal adsorption material. And (3) carrying out electrodeposition operation by using the nickel-containing desorption solution to obtain nickel metal or nickel metal powder, wherein the desorbed heavy metal adsorption material can be recycled. The method has the advantages of convenience in operation and simplicity in equipment, but the production process of the heavy metal adsorption material is complex, the capacity and the adsorption efficiency of the heavy metal adsorption material are reduced after the heavy metal adsorption material is used for multiple times, the heavy metal adsorption material is easily affected by insoluble substances and impurities in a system, and the heavy metal adsorption material needs to be replaced and needs to be further treated after being replaced.

CN108569723A discloses a method for treating nickel-containing electroplating wastewater by a chemical precipitation method, wherein the nickel-containing electroplating wastewater enters a reactor, sodium sulfide and calcium hydroxide are added into the reactor at the same time, the full reaction is carried out under the stirring condition, the stirring is stopped after 20 minutes, after 5 days of precipitation in the reactor, the supernatant is discharged into the next reactor, after the calcium hydroxide is added again for full reaction, and after 1 day of standing, the supernatant is discharged by a drain valve. The method removes nickel in a precipitation form, simultaneously the removal rate of nickel can reach 99%, the recovery of nickel is improved on the basis of effective treatment of sewage, and the method has the advantages of simple process method and low operation cost, but the method needs huge equipment, limited treatment capacity and longer treatment time, the separation effect is poor due to impurity ions carried by nickel precipitation, and meanwhile, the nickel precipitation sludge needs to be matched with working sections such as dehydration, retreatment and the like. Otherwise, secondary pollution is easily caused.

The solvent extraction method has the characteristics of high-efficiency extraction, fine separation, energy conservation, low carbon, continuous automatic operation, easy industrialization and the like, and becomes a research hotspot for recovering noble metals such as nickel and the like from waste batteries at present. CN109055746A discloses a method for recovering valuable metals from high-nickel lithium ion battery anode waste, firstly, manganese and cobalt are selectively extracted from high-nickel leachate by using a solvent extraction method, and the extraction system is P507 or P204 or Cyanex272 and sulfonated kerosene; then, further separating nickel and lithium in the raffinate by a solvent extraction method; and finally, manganese ions are precipitated from the manganese and the cobalt obtained by extraction and separation by adopting a selective oxidation precipitation method, so that the separation of the cobalt and the manganese is realized, the method has the advantages of simple system, good separation effect and simple operation process steps, and the high-efficiency recovery of all components of nickel, cobalt, manganese and lithium resources in the high-nickel lithium ion battery waste is realized. However, the extractant selected in this method brings a lot of lithium to the nickel when extracting nickel, and a large amount of acid is needed to wash the lithium off, which results in high extraction cost of nickel, low recovery rate, and the like, and the separation efficiency of nickel and lithium is still to be improved.

Therefore, it is important to develop a method for separating nickel and magnesium with low acid consumption, high extraction efficiency and low cost to improve the separation efficiency and recovery rate of nickel and magnesium.

Disclosure of Invention

Aiming at the defects of the prior art, the invention aims to provide a method for separating nickel and magnesium and application thereof.

In order to achieve the purpose, the invention adopts the following technical scheme:

in a first aspect, the present invention provides a method for separating nickel and magnesium and applications thereof, wherein the separation method comprises the following steps:

(1) preparing a high-purity extracting agent and a diluting agent into an extracted organic phase with a certain volume fraction, and then performing saponification reaction on the extracted organic phase and an alkaline compound to obtain a saponified organic phase;

the high-purity extractant is a carboxylic acid compound BC197 with the structure shown in the formula I:

wherein, C₈H₁₇Is a straight or branched chain alkane group.

(2) Mixing the saponified organic phase obtained in the step (1) with a nickel-magnesium feed liquid, extracting, clarifying and splitting phases to obtain a loaded organic phase and an extracted water phase; the loaded organic phase contains metallic nickel ions;

(3) carrying out back extraction on the loaded organic phase obtained in the step (2) by using a back extractant to obtain a metal ion enriched solution and a regenerated organic phase; the metal ion-enriched solution contains nickel ions.

The method for separating nickel and magnesium mainly comprises three steps, wherein in the step (1), an extraction organic phase and an alkaline compound are subjected to saponification reaction, and the water phase balance pH value of an extraction system is controlled in a proper range so as to better separate nickel and magnesium metal ions; step (2) adopting the saponified organic phase-to-nickel-magnesium feed liquid to carry out mixed extraction, clarifying and layering to obtain a loaded organic phase and an extracted water phase, wherein the extracted water phase contains magnesium ions, and nickel and magnesium are separated in the step; and (3) carrying out back extraction on the loaded organic phase by using a back extractant, so that a metal ion enriched solution containing nickel ions is obtained on one hand, and the organic phase is regenerated on the other hand, thereby being beneficial to recycling and reducing the cost. The whole separation process has low acid consumption, simple operation, low cost and good nickel and magnesium separation effect.

Preferably, the high purity extractant is present in an amount of 5 to 30% by volume of the organic phase to be extracted, for example 5%, 6%, 8%, 10%, 12%, 15%, 18%, 20%, 21%, 23%, 25%, 27% or 30%, and the specific values therebetween, including for brevity and clarity, are not exhaustive of the invention.

Preferably, the diluent comprises any one or a combination of at least two of Escaid110, mineral spirits, toluene, hexane, heptane, dodecane, or kerosene; more preferably Escaid110 and/or dodecane.

Preferably, the basic compound of step (1) comprises an inorganic base.

Preferably, the inorganic base comprises any one of sodium hydroxide, magnesium oxide, potassium hydroxide or ammonia water or a combination of at least two of the foregoing.

Preferably, the volume ratio of the saponified organic phase in the step (2) to the nickel-magnesium feed liquid is 1 (0.1-10), such as 1:0.1, 1:1, 1:1.5, 1:2, 1:2.5, 1:3, 1:3.5, 1:4, 1:4.5, 1:5, 1:5.5, 1:6, 1:6.5, 1:7, 1:7.5, 1:8, 1:8.5, 1:9, or 1: 9.5.

As a preferred technical scheme, the volume ratio of the saponified organic phase to the nickel-magnesium feed liquid in the step (2) is 1 (0.1-10), and the overlarge volume ratio causes the volume proportion of the nickel-magnesium feed liquid to be too small, so that magnesium-containing extract liquid is entrained or extracted by magnesium ions, and the later-stage metal enrichment concentration is influenced; too small a volume ratio results in insufficient extraction capacity of the extracted organic phase, resulting in incomplete extraction of metallic nickel ions and difficulty in uniform mixing.

Preferably, the pH of the raffinate water phase in step (2) is 5.0 to 7.8, for example 5.0, 5.8, 6.0, 6.4, 6.7, 7.0, 7.1, 7.2 or 7.7, and the specific values therebetween are not exhaustive, and for brevity and clarity, the invention is not intended to be limited to the specific values included in the ranges.

As a preferred technical scheme of the invention, the pH value of the raffinate water phase is 5.0-7.8, the pH value is too small, and the nickel extraction rate is low; the pH value is too large, magnesium extracted to an organic phase in the nickel-magnesium feed liquid is increased, and the washing cost is increased.

Preferably, the extraction of step (2) is carried out under stirring conditions.

Preferably, the stirring speed in step (2) is 100-800 rpm/min, such as 120rpm/min, 140rpm/min, 150rpm/min, 300rpm/min, 500rpm/min, 700rpm/min or 790rpm/min, and the specific points between the above points are limited by space and for the sake of brevity, and the invention is not exhaustive.

Preferably, the stirring and mixing time is 3-30 min, such as 3min, 5min, 8min, 10min, 12min, 15min, 18min, 20min, 22min, 25min or 28min, and the specific values therebetween are limited by space and for brevity, the invention is not exhaustive of the specific values included in the range.

Preferably, the extraction in step (2) is a multi-stage countercurrent fractional extraction.

Preferably, the multistage countercurrent fractional extraction has extraction stages ranging from 2 to 18, such as 3, 4, 5, 6, 7, 8, 9, 12, 15 or 17, and specific points between the above points are not exhaustive for the purpose of space and simplicity.

Preferably, the layering time in step (2) is 2-50 min, such as 10min, 15min, 20min, 25min, 30min, 35min, 40min or 45min, and the specific values therebetween are limited by space and for the sake of brevity, and the invention is not exhaustive.

Preferably, the stripping agent comprises a mineral acid.

Preferably, the inorganic acid comprises any one of hydrochloric acid, nitric acid or sulfuric acid, or a combination of at least two thereof.

Preferably, the concentration of the inorganic acid in the stripping agent is 0.5-4 mol/L, such as 0.6mol/L, 0.9mol/L, 1.2mol/L, 1.5mol/L, 1.8mol/L, 2.1mol/L, 2.4mol/L, 2.7mol/L, 3mol/L, 3.3mol/L, 3.6mol/L or 3.9mol/L, and the specific values therebetween are limited by space and for the sake of brevity, and the invention is not exhaustive.

Preferably, the back extraction in the step (3) has the number of stages of 1-10, such as 2, 3, 4, 5, 6, 8 or 9 stages.

Preferably, the volume ratio of the stripping agent to the loaded organic phase is 1 (0.1-10), such as 1:0.5, 1:1, 1:1.5, 1:2, 1:2.5, 1:3, 1:3.5, 1:4, 1:4.5, 1:5, 1:5.5, 1:6, 1:6.5, 1:7, 1:7.5, 1:8, 1:8.5, 1:9 or 1: 9.5.

Preferably, the back extraction is preceded by a washing step of the loaded organic phase obtained in step (2).

Preferably, the washing stages are 2 to 16 stages, such as 3, 4, 5, 6, 7, 10, 12, 15, etc.;

preferably, the washing comprises washing with mineral acid and/or acidified water, nickel sulfate solution;

preferably, the pH of the mineral acid and/or acidified water is between 0.1 and 2, such as 0.1, 0.5, 0.7, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8 or 1.9, and the specific values therebetween are not exhaustive, and for brevity and clarity, the invention is not intended to be limited to the specific values encompassed by the scope.

Preferably, the nickel sulfate solution is 0.5-20 g/L; e.g., 0.5g/L, 1g/L, 3g/L, 5g/L, 12g/L, 13g/L, 15g/L, 17g/L, 18g/L, or 19g/L, and the specific values therebetween, are not intended to be limiting in space and for the sake of brevity and not to be exhaustive of the invention in any way including the specific values recited herein.

Preferably, the separation method specifically comprises the following steps:

(1) carrying out saponification reaction on the extracted organic phase and an alkaline compound to obtain a saponified organic phase; the extraction organic phase comprises a diluent and a carboxylic acid compound BC197 which comprises a structure shown as a formula I:

wherein, the branched chain C₈H₁₇Being straight-chain alkane radicals

(2) Extracting and layering the saponified organic phase-to-nickel-magnesium feed liquid obtained in the step (1) according to the volume ratio of 1 (0.1-10) to obtain a nickel ion-containing loaded organic phase and a magnesium ion-containing extraction water phase with the pH value of 5.0-7.8;

(3) washing the loaded organic phase obtained in the step (2) by using a detergent, and then back-extracting by using a back-extractant to obtain a metal ion enriched solution containing nickel ions and a regenerated organic phase; the volume ratio of the stripping agent to the loaded organic phase is 1 (0.1-10), and the regenerated organic phase can be recycled.

In a second aspect, the present invention provides a use of the separation method according to the first aspect for separating nickel and magnesium from a battery recycle waste liquid.

Preferably, the battery is a ternary nickel-cobalt-manganese ion battery.

In a third aspect, the invention provides an application of an extraction reagent containing carboxylic acid compounds with the structure shown in formula I in separation of nickel and magnesium.

Compared with the prior art, the invention has the following beneficial effects:

the method for separating nickel and magnesium provided by the invention comprises the steps of firstly saponifying an extraction organic phase containing carboxylic acid compounds with specific structures to obtain a saponified organic phase, then extracting nickel-magnesium material liquid by utilizing the saponified organic phase to separate nickel and magnesium, and finally back-extracting the extracted organic phase containing nickel to obtain a regenerated organic phase and a metal ion enriched solution.

Detailed Description

The technical solution of the present invention is further explained by the following embodiments. It should be understood by those skilled in the art that the examples are only for the understanding of the present invention and should not be construed as the specific limitations of the present invention.

Preparation example 1

A carboxylic acid compound BC197 has the following structure:

wherein, C₈H₁₇Is a straight or branched chain alkane group;

the preparation method comprises the following steps:

in a 250mL round bottom flask was added 25g (0.15mol) of methyl tetrahydrophthalic anhydride, 100mL of toluene, 25mL (0.19mol) of isooctanol, a few drops of concentrated sulfuric acid, heated to 80 ℃ and stirred for 1.5h, the reaction was stopped and the remaining isooctanol was distilled off to give 25.7g of product in about 58% yield.

Characterization data:¹H NMR(400MHz,CDCl₃)δ11.5(1H),5.6(1H),3.9(1H),3.1(2H),2.8(1H),2.2(4H),1.9(3H),1.5(3H),1.2(6H),0.89(3H),0.85(3H)；MS:296.2。

preparation example 2:

a250 mL round bottom flask was charged with 25g (0.15mol) of methyl tetrahydrophthalic anhydride, 100mL of toluene, 25mL (0.19mol) of octanol, a few drops of concentrated sulfuric acid, heated to 80 ℃ and stirred for 1.5h, the reaction was stopped and the remaining isooctanol was distilled off to give 27.2g of product in about 61% yield.

Characterization data:¹H NMR(400MHz,CDCl₃)δ10.4(1H),5.3(1H),3.7(1H),2.7(1H),2.3(2H),2.0(2H),1.65(3H),1.4(4H),1.3(8H),0.87(3H)；MS:296.2。

example 1

A method for separating nickel and magnesium and application thereof are disclosed, which comprises the following steps:

(1) dissolving carboxylic acid compound BC197 obtained in preparation example 1 in diluent Escaid110 to enable the volume percentage content of a high-purity extracting agent in the Escaid110 to be 25%, adding 10mol/L NaOH solution, and mixing to obtain a saponified organic phase with the saponification degree of 30%, wherein the saponified organic phase is used as an organic phase system;

(2) taking a nickel-magnesium feed liquid as an aqueous phase system (1.70 g/L nickel, 19g/L magnesium and 5.20 pH value, specifically derived from an intermediate material in nickel purification of a waste lithium ion battery anode material leaching liquid), respectively flowing in from two ends of an extractor with a saponified organic phase obtained in the step (1) (the flow ratio of the saponified organic phase to the nickel-magnesium feed liquid is 1:4), mixing and keeping the mixing speed at 600rpm/min, the mixing time at 15min and the temperature at 25 ℃, carrying out multi-stage countercurrent fractional extraction, wherein the extraction stage number is 10 stages, standing for 22min, and layering to obtain a nickel ion-loaded organic phase and a magnesium ion-containing outlet aqueous phase (namely an extraction residual aqueous phase) with the pH value of 7;

(3) carrying out 10-stage countercurrent washing on the loaded organic phase obtained in the step (2) by using a sulfuric acid solution with the pH value of 1, and then carrying out back extraction by using sulfuric acid with the concentration of 2mol/L, wherein the number of the back extraction stages is 6; the flow ratio of the detergent sulfuric acid solution to the loaded organic phase is 1:0.2, and the flow ratio of the 2mol/L sulfuric acid to the loaded organic phase is 1:10, so that a metal ion enriched solution and a regenerated organic phase are obtained.

Example 2

A method for separating nickel and magnesium and application thereof are disclosed, which comprises the following steps:

(1) dissolving carboxylic acid compound BC197 obtained in preparation example 1 in Escaid110, wherein the volume percentage of BC196 in the Escaid110 is 25%, adding 10mol/L NaOH solution, and mixing to obtain a saponified organic phase with the saponification degree of 23%, wherein the saponified organic phase is used as an organic phase system;

(2) taking a nickel-magnesium feed liquid as an aqueous phase system (containing 1.70g/L of nickel, 19g/L of magnesium and having a pH value of 5.20, specifically derived from an intermediate material in nickel purification of a waste lithium ion battery anode material leaching solution), respectively flowing the nickel-magnesium feed liquid and the saponified organic phase in the step (1) from two ends of an extractor (the volume ratio of the saponified organic phase to the nickel-magnesium feed liquid is 1:5), mixing and keeping the mixing speed at 760rpm/min, the mixing time at 5min and the temperature at 25 ℃, performing multi-stage countercurrent fractional extraction, wherein the extraction stages are 12 stages, standing for 10min, and layering to obtain a nickel ion-loaded organic phase and a magnesium ion-containing raffinate aqueous phase with a pH value of 7.4;

(3) carrying out 18-stage countercurrent washing on the loaded organic phase obtained in the step (2) by using sulfuric acid with the pH value of 0.9, and then carrying out back extraction by using sulfuric acid with the concentration of 2mol/L, wherein the number of the back extraction stages is 6; the flow ratio of the washing sulfuric acid to the loaded organic phase is 1:0.25, and the flow ratio of the 2mol/L sulfuric acid to the loaded organic phase is 1:10, so that a metal ion enriched solution and a regenerated organic phase are obtained.

Example 3

A method for separating nickel and magnesium and application thereof are disclosed, which comprises the following steps:

(1) dissolving carboxylic acid compound BC197 obtained in preparation example 1 in dodecane, wherein the volume percentage of the carboxylic acid compound in the dodecane is 25%, adding an ammonia water solution with the concentration of 11mol/L, and mixing to obtain a saponified organic phase with the saponification degree of 30%, wherein the saponified organic phase is used as an organic phase system;

(2) taking a nickel-magnesium feed liquid as an aqueous phase system (containing 1.70g/L of nickel, 19g/L of magnesium and having a pH value of 5.20, specifically derived from an intermediate material in the nickel purification of a waste lithium ion battery anode material leaching solution), respectively flowing into the saponification organic phase from two ends of an extractor (the volume ratio of the saponification organic phase to the nickel-magnesium feed liquid is 1:4.5) in the step (1), mixing and keeping the stirring speed at 800rpm/min, the mixing time at 5min and the temperature at 25 ℃, carrying out multi-stage countercurrent fractional extraction, wherein the extraction stages are 6 stages, clarifying and layering for 10min to obtain a nickel ion-loaded organic phase and a magnesium ion-containing raffinate aqueous phase with a pH value of 6.8;

(3) carrying out 8-stage countercurrent washing on the loaded organic phase obtained in the step (2) by using sulfuric acid with the pH value of 1.0, and then carrying out back extraction by using sulfuric acid with the concentration of 2.5mol/L for 4 times; the flow ratio of the washing sulfuric acid to the loaded organic phase is 1:5, and the flow ratio of the 3mol/L sulfuric acid to the loaded organic phase is 1:10, so that the metal ion negative electrode solution and the regenerated organic phase are obtained.

Example 4

A method for separating nickel and magnesium and its use, which differs from example 1 only in that: the sulfuric acid detergent in step (3) was replaced with 1.0g/L nickel sulfate solution, and the amounts of other components and experimental conditions were the same as in example 1.

Comparative example 1

A method for separating nickel and magnesium and its use, which differs from example 1 only in that: the carboxylic acid compound BC197 in the step (1) is replaced by an equal amount of the extractant P507 (2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester), and the amounts of other components and experimental conditions are the same as those in the example 1.

Comparative example 2

A method for separating nickel and magnesium and its use, which differs from example 1 only in that: the carboxylic acid compound BC197 in step (1) was replaced by an equal amount of extractant C272 (bis- (2, 4, 4-trimethyl) pentylphosphonic acid), and the amounts of other components and experimental conditions were the same as in example 1.

And (3) performance testing:

the proportion of saponification refers to the alkali metal NH in the extractant⁺ ₄And/or Na⁺The ratio of the original hydrogen ions, i.e., (V base XC base)/(V having XC) X100% (1)

In the formula (1), V is the volume mL of the added alkali aqueous solution, C is the concentration mol/L of the alkali in the added alkali aqueous solution, V is the volume mL of the organic phase, and C is the concentration mol/L of the extractant in the organic phase.

In the examples of the present invention, the content of metal ions in the aqueous phase was measured by inductively coupled plasma emission spectrometry (ICP-OES), and then the content of metal ions in the organic phase was determined by the subtraction method.

The extracted aqueous phase and the metal ion-enriched solution obtained in the step (2) of the extraction method described in examples 1 to 4 and comparative examples 1 to 2 were tested according to the above test methods, and the results are shown in table 1.

TABLE 1

As can be seen from the data in Table 1, the method for separating nickel and magnesium and the application thereof provided by the invention have better separation effect compared with the prior art. Specifically, the purity of nickel in the metal ion enriched solution obtained in example 1 is as high as 99.9%, and the content of nickel in the extracted water phase is less than 0.5mg/L, which means that compared with the nickel and magnesium separation method (comparative example 1 and comparative example 2) provided in the prior art, the purity of nickel in the metal ion enriched solution is improved by 0.5-1.4%, and the content of nickel in the extracted water phase is reduced by 84-91%, which indicates that the nickel and magnesium separation method and the nickel and magnesium separation effect applied by the method provided by the invention are better.

The applicant states that the present invention is illustrated by the above examples as a method for separating nickel and magnesium and its application, but the present invention is not limited to the above process steps, i.e. it is not meant that the present invention must rely on the above process steps for its implementation. It will be apparent to those skilled in the art that any modification of the present invention, equivalent substitutions of selected materials and additions of auxiliary components, selection of specific modes and the like, which are within the scope and disclosure of the present invention, are contemplated by the present invention.