CO2 responsive microemulsion and metal ion separation method

Abstract

The invention discloses a CO2 response type microemulsion and a metal ion separation method. The CO2 response type microemulsion and metal ion separation method comprises the following steps: S1, preparation of a surfactant; S2, preparation of an oil phase and a water phase; S3, preparation of a microemulsion; according to the invention, the organic amine molecule with two or more amino groups and the organic acid molecule are self-assembled, the extraction function is retained while the response type microemulsion is constructed, and by controlling the number of amino groups of the organic amine molecule, the number and distribution of other polar groups, the alkyl chain length, the number and distribution of carboxyl groups of the organic acid molecule and the like, the response type microemulsion is obtained. According to the method, cobalt and nickel metal ions are separated and recycled by adjusting and controlling a liquid-liquid interface structure and cooperatively adjusting and controlling responsiveness and extraction performance of the microemulsion, the problem of demulsification and reverse extraction is solved, and a mild mode is adopted, namely, carbon dioxide gas is used for stimulating demulsification of the microemulsion, so that the purpose of efficient reverse extraction is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of formulation design and preparation of responsive microemulsions, and in particular to a CO2 responsive microemulsion and a metal ion separation method. Background Art

[0002] For example, Chinese patent publication number CN115433831A discloses a method for selectively extracting indium from blast furnace gas mud leachate using a microemulsion, belonging to the field of hydrometallurgical separation and extraction of indium. This method achieves selective extraction of indium by preparing a microemulsion containing di-(2-ethylhexyl) phosphate (DEHPA), sorbitan oleate (Span 80), an oil phase, and an alkaline solution, while effectively separating impurity elements such as iron.

[0003] For example, Chinese patent publication number CN105177294B discloses a microemulsion system and method for extracting and separating nickel and lithium, which utilizes saponified P204 as a surfactant, n-hexanol as a co-surfactant, and n-heptane as an organic phase to construct a stable microemulsion system.

[0004] For example, Chinese patent publication number CN109628769A describes a method for extracting light rare earth elements from acidic solutions using ionic liquid microemulsions, belonging to the fields of rare earth hydrometallurgy and ionic liquid extraction technology. This method, by adding ionic liquids to the microemulsion system to replace traditional organic solvents, addresses the issues of traditional solvents such as high volatility, toxicity, and environmental pollution, while also compensating for the high viscosity of ionic liquids.

[0005] For example, Chinese patent publication number CN115449631A describes a method for separating cobalt and nickel from a sulfuric acid leachate using a microemulsion, which belongs to the field of hydrometallurgical separation and extraction of cobalt. This method uses thiocyanate as a complexing agent to complex cobalt ions into (Co(SCN)4)2-anions, thereby creating a charge difference with the nickel ions in the solution, facilitating selective extraction. Subsequently, extraction and separation are performed using a microemulsion system comprising a quaternary ammonium salt solution, a medium-chain alcohol solution, an oil phase, a sodium salt solution, and an alkaline solution.

[0006] For example, Chinese patent publication number CN111057875B, a method for separating vanadium and chromium from solution using microemulsion, aims to solve the problems of existing processes and provide a green, environmentally friendly and energy-efficient technology;

[0007] Limitations of multi-stage stripping design: The aforementioned Chinese patent, CN115433831A, mentions efficient indium recovery through three-stage stripping. However, the multi-stage stripping design relies on good phase separation between each stage. If the phase separation is incomplete, some indium may remain in the microemulsion, reducing the overall stripping efficiency.

[0008] The current technology related to this patent does not provide a specific description of the stripping conditions (time, temperature, pH, reagent concentration, etc.), stripping mechanism, etc. If the stripping temperature is too low, it may affect the diffusion rate of metal ions, thereby affecting the stripping efficiency. If the stirring time and standing time during the stripping process are insufficient, the metal ions cannot be fully transferred to the aqueous phase. If the stirring speed is too low, the microemulsion phase may not be in sufficient contact with the stripping agent, affecting the stripping efficiency.

[0009] In order to overcome these disadvantages, the present invention provides a CO2-responsive microemulsion and a metal ion separation method. Summary of the Invention

[0010] The purpose of the present invention is to solve the shortcomings of the prior art and to propose a CO2-responsive microemulsion and a metal ion separation method.

[0011] In order to achieve the above object, the present invention adopts the following technical solution: a CO2-responsive microemulsion and metal ion separation method, comprising the following steps:

[0012] S1. Preparation of surfactant;

[0013] S2, preparation of oil phase and water phase;

[0014] S3, preparation of microemulsion;

[0015] S4. Preparation of ionic solution pH regulator;

[0016] S5. Preparation of ionic solution;

[0017] S6. Extraction of metal ions.

[0018] Furthermore, in step S1, the specific steps of preparing the surfactant include: at room temperature of 25°C, taking 5.05g of polyetheramine and 5.65g of oleic acid, wherein the molar ratio of the two is 1:1, mixing them in a 50ml glass sample bottle, magnetically stirring at a speed of 500rpm, and stirring for 15min to obtain a mixture A, then taking 11g of n-butanol and mixing it with the mixture A in a 50ml glass sample bottle, magnetically stirring at a speed of 500rpm, and stirring for 15min to prepare a surfactant.

[0019] Furthermore, the polyetheramine can be replaced by any one of the following materials: dodecylamine, 1,4-butanediamine, 1,10-decanediamine, triethylenetetramine, 1,8-diaminooctane, 1,7-diaminoheptane, and 1,2-diethane.

[0020] Furthermore, in step S2, the specific steps of preparing the oil phase include: taking 1g of n-heptane and 8g of surfactant and mixing them in a 50ml glass sample bottle at room temperature of 25°C, magnetically stirring at a speed of 500rpm for 15min to prepare the oil phase.

[0021] Furthermore, in step S2, the specific steps of preparing the aqueous phase include: taking 0.73 g of sodium chloride and preparing 25 ml of 0.5 M NaCl solution at room temperature (25° C.) to prepare the aqueous phase.

[0022] Furthermore, in step S3, the specific steps of preparing the microemulsion include: titrating the oil phase with the water phase, using magnetic stirring at a rotation speed of 500 rpm, to prepare a microemulsion, in which the oil phase accounts for 9.35%, the surfactant accounts for 74.83%, and the water phase accounts for 15.82%.

[0023] Furthermore, in step S4, the specific steps of preparing the ionic solution pH regulator include: taking 8.3 ml of concentrated hydrochloric acid at room temperature 25°C, dissolving it in a 100 ml volumetric flask filled with pure water, and diluting the volume to 100 ml with pure water to prepare a 1M HCl solution, taking 1 g of sodium hydroxide, dissolving it with pure water and diluting the volume to 25 ml to prepare a 1M NaOH solution, and preparing the ionic solution pH regulator.

[0024] Furthermore, in step S5, the specific steps of preparing the ionic solution include: at room temperature of 25° C., taking 0.035 g of cobalt chloride hexahydrate, nickel chloride hexahydrate, 2.9 g of sodium chloride, and 4 g of sodium thiocyanate, dissolving them with pure water, and then adjusting the volume to 100 ml, and then adjusting the pH of the ionic solution prepared in step S4 with the pH regulator. After the pH of the solution is detected in real time with a pH meter, an ionic solution is prepared.

[0025] Furthermore, in step S6, the specific steps of metal ion extraction include: at room temperature of 25°C, taking 14 ml of the ionic solution prepared in step S5 and 2 ml of the microemulsion prepared in step S3, the ratio is 7:1, mixing them in a 20 ml glass sample bottle for extraction, magnetic stirring, a speed of 500 rpm, and an extraction time of 10 min to obtain a mixture B, taking 1 ml of the lower layer liquid after extraction of the mixture B into a 10 ml centrifuge tube, diluting it with pure water to 10 ml and sealing it for storage, wherein the upper layer is the microemulsion phase, and the lower layer is the ionic solution phase after extraction, after taking the lower layer to detect the cobalt and nickel ion concentration, the extraction rate of the microemulsion for cobalt and nickel ions can be calculated, thereby measuring the extraction ability of the microemulsion for cobalt and nickel ions.

[0026] Beneficial effects of the present invention:

[0027] This CO2-responsive microemulsion and metal ion separation method utilizes organic amine molecules with two or more amino groups and organic acid molecules to self-assemble, retaining the extraction function while constructing a responsive microemulsion. By controlling the number of amino groups, the number and distribution of other polar groups, and the alkyl chain length of the organic amine molecules, and the number and distribution of carboxyl groups of the organic acid molecules, the liquid-liquid interface structure is regulated, and the responsiveness and extraction performance of the microemulsion are synergistically regulated to achieve the separation and recovery of cobalt and nickel metal ions. This method solves the problem of demulsification and stripping, and adopts a "gentle" approach, namely using carbon dioxide gas to stimulate microemulsion demulsification, so as to achieve the purpose of efficient stripping. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solution of the present invention, the following is a brief introduction to the drawings required for use in the description of the specific implementation methods. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0029] Figure 1 Schematic diagram showing the effect of extraction time on extraction rate of the present invention;

[0030] Figure 2 Schematic diagram showing the effect of extraction time on extraction rate of the present invention;

[0031] Figure 3 Schematic diagram of a comparative experiment of the oil phase to surfactant mass ratio of 1:6 and 1:8 according to the present invention;

[0032] Figure 4 Schematic diagram of a comparative experiment of the oil phase to surfactant mass ratio of 1:6 and 1:8 according to the present invention;

[0033] Figure 5 Schematic diagram of the effect of NaSCN molar concentration on extraction rate of the present invention.

[0034] Figure 6 Schematic diagram showing the effect of NaSCN molar concentration on extraction rate of the present invention;

[0035] Figure 7 Schematic diagram showing the effect of the pH of the ion solution on the extraction rate of the present invention;

[0036] Figure 8 Schematic diagram showing the effect of the pH of the ion solution on the extraction rate of the present invention;

[0037] Figure 9 Flowchart of the present invention. DETAILED DESCRIPTION

[0038] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0039] like Figure 1-8 As shown, the present invention has the following specific embodiments.

[0040] Example 1

[0041] A CO2-responsive microemulsion and metal ion separation method comprises the following steps:

[0042] S1. Preparation of surfactant;

[0043] S2, preparation of oil phase and water phase;

[0044] S3, preparation of microemulsion;

[0045] S4. Preparation of ionic solution pH regulator;

[0046] S5. Preparation of ionic solution;

[0047] S6. Extraction of metal ions.

[0048] In step S1, the specific steps of preparing the surfactant include: taking 5.05g of polyetheramine and 5.65g of oleic acid at a molar ratio of 1:1 at room temperature of 25°C, mixing the mixture in a 50ml glass sample bottle, magnetically stirring at a speed of 500rpm, and stirring for 15min to obtain a mixture A, then taking 11g of n-butanol and mixing the mixture A in a 50ml glass sample bottle, magnetically stirring at a speed of 500rpm, and stirring for 15min to prepare a surfactant.

[0049] The polyetheramine can be replaced by any one of the following materials: dodecylamine, 1,4-butanediamine, 1,10-decanediamine, triethylenetetramine, 1,8-diaminooctane, 1,7-diaminoheptane, and 1,2-diethane.

[0050] In step S2, the specific steps of preparing the oil phase include: taking 1g of n-heptane and 8g of surfactant and mixing them in a 50ml glass sample bottle at room temperature of 25°C, magnetically stirring at a speed of 500rpm for 15 minutes to prepare the oil phase.

[0051] In step S2, the specific steps of preparing the aqueous phase include: taking 0.73 g of sodium chloride and preparing 25 ml of 0.5 M NaCl solution at room temperature (25° C.) to prepare the aqueous phase.

[0052] In step S2, the specific steps of preparing the aqueous phase include: taking 0.73 g of sodium chloride and preparing 25 ml of 0.5 M NaCl solution at room temperature (25° C.) to prepare the aqueous phase.

[0053] In step S3, the specific steps of preparing the microemulsion include: titrating the oil phase with the water phase, using magnetic stirring at a speed of 500 rpm, to prepare a microemulsion, wherein the oil phase accounts for 9.35%, the surfactant accounts for 74.83%, and the water phase accounts for 15.82%.

[0054] In step S4, the specific steps of preparing the ionic solution pH regulator include: taking 8.3 ml of concentrated hydrochloric acid at room temperature of 25° C., dissolving it in a 100 ml volumetric flask filled with pure water, and diluting the volume to 100 ml with pure water to prepare a 1M HCl solution; taking 1 g of sodium hydroxide, dissolving it in pure water and diluting the volume to 25 ml to prepare a 1M NaOH solution, and preparing the ionic solution pH regulator.

[0055] In step S5, the specific steps of preparing the ionic solution include: taking 0.035g of cobalt chloride hexahydrate, nickel chloride hexahydrate, 2.9g of sodium chloride, and 4g of sodium thiocyanate at room temperature of 25°C, dissolving them in pure water, and then adjusting the volume to 100ml, then adjusting the pH of the ionic solution with the pH regulator prepared in step S4, and detecting the pH of the solution in real time with a pH meter to prepare the ionic solution.

[0056] In step S6, the specific steps of metal ion extraction include: taking 14 ml of the ionic solution prepared in step S5 and 2 ml of the microemulsion prepared in step S3 at a ratio of 7:1 at room temperature of 25° C., mixing them in a 20 ml glass sample bottle for extraction, magnetic stirring at a speed of 500 rpm, and an extraction time of 10 minutes to obtain a mixture B, taking 1 ml of the lower layer liquid after the extraction of the mixture B into a 10 ml centrifuge tube, diluting it with pure water to 10 ml and sealing it for storage, wherein the upper layer is the microemulsion phase and the lower layer is the ionic solution phase after extraction, and after taking the lower layer to detect the cobalt and nickel ion concentration, the extraction rate of the microemulsion for cobalt and nickel ions can be calculated, thereby measuring the extraction ability of the microemulsion for cobalt and nickel ions.

[0057] Example 2

[0058] like Figure 1-2 As shown in Figure 2, the effect of extraction time on extraction rate was studied:

[0059] 1. Take 5.05g D-230 and 5.65g oleic acid (molar ratio of 1:1) and stir to mix;

[0060] 2. Take 11g of n-butanol and mix it evenly with the above system;

[0061] 3. n-heptane as the oil phase and 0.5M NaCl solution as the water phase;

[0062] 4. Mix the oil phase and the surfactant in a mass ratio of 1:4, titrate with the aqueous phase, and prepare a microemulsion for extraction.

[0063] 5. Prepare ionic solution samples by dissolving 100 mg / L CoCl2, 100 mg / L NiCl2, 0.5 M NaCl, and 0.5 M NaSCN in deionized water;

[0064] 6. Adjust the pH of the ionic solution to 1 with 1M HCl solution;

[0065] 7. Extraction was performed using a microemulsion with an oil phase to surfactant mass ratio of 1:4;

[0066] 8. The aqueous solution and microemulsion were mixed at room temperature in a volume ratio of 7:1, magnetically stirred at a speed of 500 rpm, and the extraction time was controlled as the only variable (2 min, 10 min, 30 min, 50 min).

[0067] In this embodiment, the extraction time is controlled as the only variable, and 10 minutes is selected as the most suitable extraction time.

[0068] Example 3

[0069] like Figure 3-4 , do a comparative experiment with the mass ratio of oil phase to surfactant of 1:6 and 1:8:

[0070] 1. Take 5.05g D-230 and 5.65g oleic acid (molar ratio of 1:1) and stir to mix;

[0071] 2. Take 11g of n-butanol and mix it evenly with the above system;

[0072] 3. n-heptane as the oil phase and 0.5M NaCl solution as the water phase;

[0073] 4. Mix the oil phase and surfactant in a mass ratio of 1:6 or 1:8, titrate with the aqueous phase, and prepare a microemulsion for extraction;

[0074] 5. Prepare ionic solution samples by dissolving 100 mg / L CoCl2, 100 mg / L NiCl2, 0.5 M NaCl, and 0.5 M NaSCN in deionized water;

[0075] 6. Adjust the pH of the ionic solution to 0.73 with 1 M HCl solution;

[0076] 7. Extraction was performed using a microemulsion with an oil phase to surfactant mass ratio of 1:6 or 1:8;

[0077] 8. Mix the aqueous solution and microemulsion in a volume ratio of 7:1 at room temperature, stir magnetically at a speed of 500 rpm, and extract for 10 min.

[0078] In this embodiment, the most suitable ratio of oil phase to surfactant is selected as 1:8.

[0079] Example 4

[0080] like Figure 5-6 , study the effect of NaSCN molar concentration on extraction rate:

[0081] 1. Take 5.05g D-230 and 5.65g oleic acid (molar ratio of 1:1) and stir to mix;

[0082] 2. Take 11g of n-butanol and mix it evenly with the above system;

[0083] 3. n-heptane as the oil phase and 0.5M NaCl solution as the water phase;

[0084] 4. Mix the oil phase and the surfactant in a mass ratio of 1:8, titrate with the aqueous phase, and prepare a microemulsion for extraction.

[0085] 5. Prepare ion solution samples by dissolving 100 mg / L CoCl2, 100 mg / L NiCl2, 0.5 M NaCl, and 0.25 M and 0.5 M NaSCN in deionized water, respectively;

[0086] 6. Adjust the pH of the ionic solution to 0.76 with 1 M HCl solution;

[0087] 7. Extraction was performed using a microemulsion with an oil phase to surfactant mass ratio of 1:8;

[0088] 8. Mix the aqueous solution and microemulsion in a volume ratio of 7:1 at room temperature, stir magnetically at a speed of 500 rpm, and extract for 10 min.

[0089] In this embodiment, the most suitable molar concentration of NaSCN is selected to be 0.5 mol / L.

[0090] Example 5

[0091] like Figure 7-8 , study the effect of ion solution pH on extraction rate:

[0092] 1. Take 5.05g D-230 and 5.65g oleic acid (molar ratio of 1:1) and stir to mix;

[0093] 2. Take 11g of n-butanol and mix it evenly with the above system;

[0094] 3. n-heptane as the oil phase and 0.5M NaCl solution as the water phase;

[0095] 4. Mix the oil phase and the surfactant in a mass ratio of 1:8, titrate with the aqueous phase, and prepare a microemulsion for extraction.

[0096] 5. Prepare ionic solution samples by dissolving 100 mg / L CoCl2, 100 mg / L NiCl2, 0.5 M NaCl, and 0.5 M NaSCN in deionized water;

[0097] 6. Adjust the pH of the ion solution to 0.5, 0.6, 0.7, 0.8, and 0.9 using 1 M HCl solution and 1 M NaOH solution;

[0098] 7. Use a microemulsion with an oil phase to surfactant mass ratio of 1:8 for extraction. Mix ionic solutions of different pH values with the microemulsion in a volume ratio of 7:1 at room temperature, stir magnetically at a speed of 500 rpm, and extract for 10 min.

[0099] In this embodiment, the most suitable pH value for the microemulsion with an oil phase to surfactant mass ratio of 1:8 was selected to be 0.9.

[0100] The preferred embodiments of the present invention disclosed above are intended only to help illustrate the present invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the present invention to specific embodiments. Obviously, many modifications and variations are possible based on the contents of this specification. These embodiments are selected and described in detail in this specification to better explain the principles and practical applications of the present invention, thereby enabling those skilled in the art to better understand and utilize the present invention. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A CO2-responsive microemulsion and metal ion separation method, characterized in that: The following steps are involved: S1. Preparation of surfactant; S2, preparation of oil phase and water phase; S3, preparation of microemulsion; S4. Preparation of ionic solution pH regulator; S5. Preparation of ionic solution; S6. Extraction of metal ions.

2. A CO2-responsive microemulsion and metal ion separation method according to claim 1, characterized in that: In step S1, the specific steps of preparing the surfactant include: taking 5.05g of polyetheramine and 5.65g of oleic acid at a molar ratio of 1:1 at room temperature of 25°C, mixing the mixture in a 50ml glass sample bottle, magnetically stirring at a speed of 500rpm, and stirring for 15min to obtain a mixture A, then taking 11g of n-butanol and mixing the mixture A in a 50ml glass sample bottle, magnetically stirring at a speed of 500rpm, and stirring for 15min to prepare a surfactant.

3. A CO2-responsive microemulsion and metal ion separation method according to claim 2, characterized in that: The polyetheramine can be replaced by any one of the following materials: dodecylamine, 1,4-butanediamine, 1,10-decanediamine, triethylenetetramine, 1,8-diaminooctane, 1,7-diaminoheptane, and 1,2-diethane.

4. A CO2-responsive microemulsion and metal ion separation method according to claim 3, characterized in that: In step S2, the specific steps of preparing the oil phase include: taking 1g of n-heptane and 8g of surfactant and mixing them in a 50ml glass sample bottle at room temperature of 25°C, magnetically stirring at a speed of 500rpm for 15 minutes to prepare the oil phase.

5. A CO2-responsive microemulsion and metal ion separation method according to claim 4, characterized in that: In step S2, the specific steps of preparing the aqueous phase include: taking 0.73 g of sodium chloride and preparing 25 ml of 0.5 M NaCl solution at room temperature (25° C.) to prepare the aqueous phase.

6. A CO2-responsive microemulsion and metal ion separation method according to claim 5, characterized in that: In step S3, the specific steps of preparing the microemulsion include: titrating the oil phase with the water phase, using magnetic stirring at a speed of 500 rpm, to prepare a microemulsion, wherein the oil phase accounts for 9.35%, the surfactant accounts for 74.83%, and the water phase accounts for 15.82%.

7. A CO2-responsive microemulsion and metal ion separation method according to claim 6, characterized in that: In step S4, the specific steps of preparing the ionic solution pH regulator include: taking 8.3 ml of concentrated hydrochloric acid at room temperature of 25° C., dissolving it in a 100 ml volumetric flask filled with pure water, and diluting the volume to 100 ml with pure water to prepare a 1M HCl solution; taking 1 g of sodium hydroxide, dissolving it in pure water and diluting the volume to 25 ml to prepare a 1M NaOH solution, and preparing the ionic solution pH regulator.

8. A CO2-responsive microemulsion and metal ion separation method according to claim 7, characterized in that: In step S5, the specific steps of preparing the ionic solution include: taking 0.035g of cobalt chloride hexahydrate, nickel chloride hexahydrate, 2.9g of sodium chloride, and 4g of sodium thiocyanate at room temperature of 25°C, dissolving them in pure water, and then adjusting the volume to 100ml, then adjusting the pH of the ionic solution with the pH regulator prepared in step S4, and detecting the pH of the solution in real time with a pH meter to prepare the ionic solution.

9. A CO2-responsive microemulsion and metal ion separation method according to claim 8, characterized in that: In step S6, the specific steps of metal ion extraction include: taking 14 ml of the ionic solution prepared in step S5 and 2 ml of the microemulsion prepared in step S3 at a ratio of 7:1 at room temperature of 25° C., mixing them in a 20 ml glass sample bottle for extraction, magnetic stirring at a speed of 500 rpm, and an extraction time of 10 minutes to obtain a mixture B, taking 1 ml of the lower layer liquid after the extraction of the mixture B into a 10 ml centrifuge tube, diluting it with pure water to 10 ml and sealing it for storage, wherein the upper layer is the microemulsion phase and the lower layer is the ionic solution phase after extraction, and after taking the lower layer to detect the cobalt and nickel ion concentration, the extraction rate of the microemulsion for cobalt and nickel ions can be calculated, thereby measuring the extraction ability of the microemulsion for cobalt and nickel ions.

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