Cobalt-nickel separation system based on oxidation coordination as well as construction method and application of cobalt-nickel separation system

Abstract

The invention provides a cobalt-nickel separation system based on oxidation coordination and a construction method and application thereof.The system comprises a feeding end solution, a discharging end solution and a separation membrane, the chemical behavior difference of cobalt and nickel after oxidation coordination is amplified, separation is achieved through the size effect of a reduced graphene oxide membrane, and the separation efficiency is improved. The invention further provides a construction method of the system, the cobalt-nickel separation system based on oxidation coordination shows excellent flux and selectivity, the preparation process is safe and simple, raw materials are low in price and easy to obtain, the preparation cost is low, and large-scale preparation is easy to achieve.

Description

Technical Field

[0001] The present application relates to the technical field of membrane separation of valuable metals in waste batteries, and in particular to a cobalt-nickel separation system based on oxidative coordination, and a construction method and application thereof. Background Art

[0002] Power battery recycling is an important part of the sustainable development of the new energy industry, and is also the key to the sustainable supply of strategic mineral resources such as lithium, nickel, and cobalt. According to the estimated service life of power batteries of 4 to 8 years, the power batteries of new energy vehicles installed on a large scale around 2017 will also usher in a recycling period this year. At the same time, driven by the sharp increase in the price of lithium, cobalt, and nickel ores, the price of used power batteries has also "risen with the tide", and the discount coefficient of some batteries (the ratio of scrap price to new price) has risen from a minimum of 60% to more than 100%. In particular, with the large-scale installation of power batteries, the contradiction between the supply and demand of resources such as lithium, cobalt, and nickel will be further intensified, and the market value of power battery recycling will become more prominent.

[0003] Membrane separation technology is an emerging separation method. It is a technology that achieves selective separation of mixtures of molecules of different particle sizes at the molecular level when they pass through a semipermeable membrane. With its advantages of simple operation, low carbon and environmental protection, sustainability, and low energy consumption, it has replaced traditional dry separation, hydrometallurgy and other technologies and become an effective way to recover valuable metals from waste batteries. Membrane separation technology mainly depends on the steric effect (relying on the size difference between membrane pores and metal ions), dielectric exclusion (energy barrier for ion solvation into nanochannels, which is caused by the orientation of water molecules on the nanochannel wall), and Donan effect (electronic interaction between membrane pores and metal ions). Among them, the steric effect is the most effective method for screening metal ions.

[0004] Compared with conventional membrane separation of valuable metals, ammonia water / hydrogen peroxide is introduced as an oxidation ligand for cobalt, and the hexahydrated cobalt ions of regular octahedrons are constructed into binuclear cobalt-ammonia complexes, which amplify the charge and size differences of cobalt-nickel ions. The size effect of reduced graphene oxide and the thermodynamic drive of ammonium chloride absorption liquid are used to construct a dual-chamber separation system, which can efficiently separate cobalt-nickel metals and realize the recycling and reuse of cobalt-nickel resources. The cobalt-nickel separation system has the advantages of being environmentally friendly, low energy consumption, high flux, and high selectivity, and the dual drive of kinetics (concentration polarization) and thermodynamics (decomposition reaction) further improves the cobalt-nickel separation efficiency, providing a possibility for the recycling and utilization of cobalt-nickel resources in waste batteries. Summary of the invention

[0005] Technical problems to be solved: In order to solve the technical problems such as the large contradiction between supply and demand of resources such as lithium, cobalt and nickel in the prior art, a cobalt-nickel separation system based on oxidative coordination and its construction method and application are provided. The system can be used to efficiently recover cobalt and nickel resources in waste batteries at room temperature. It not only has a selectivity significantly higher than that of ionic liquids and single membrane materials, but also has a very high flux.

[0006] A method for constructing a cobalt-nickel separation system based on oxidative coordination, the method comprising the following steps:

[0007] The first step is to prepare a feed end solution: nickel salt or cobalt salt is dispersed in a mixed solution of ammonia water and hydrogen peroxide, and a 0.1-0.5 mol / L nickel ammonia or cobalt ammonia solution is prepared by ultrasonication for half an hour as a feed end solution;

[0008] The second step is to prepare a discharge end solution: ammonium chloride is dispersed in deionized water to obtain a 0.01-5 mol / L ammonium chloride solution as a discharge end solution;

[0009] The third step is to prepare a precursor solution: 0.6 mg of graphene oxide is added to 40 mL of deionized water according to a mass volume ratio to prepare a precursor solution;

[0010] Step 4: Dissolve 160 μL of concentrated ammonia water and 6 mg of glucose in the precursor solution prepared in the third step according to the mass volume ratio, heat in an oven at 80 to 120° C. for 30 to 60 minutes, and naturally cool to room temperature to obtain a reduced graphene oxide dispersion;

[0011] Step 5: Using the dopamine-treated nylon membrane as a substrate, pouring the prepared reduced graphene oxide dispersion into the membrane and vacuum filtering for 1 to 3 days to obtain a reduced graphene oxide membrane;

[0012] Step 6: Add a feed end solution to one end of the H-type electrolytic cell and add a discharge end solution to the other end, and separate the feed end solution and the discharge end solution with the prepared reduced graphene oxide membrane;

[0013] Step 7: Add magnets at both ends and stir at a speed of 500-600 rad / s for 1 hour. Driven by osmotic pressure, metal ions diffuse from the feed end to the discharge end.

[0014] Furthermore, the mixed solution of ammonia water and hydrogen peroxide in the first step is prepared by uniformly mixing 20-25 mL of 25 wt % concentrated ammonia water and 0.01-5 mL of 30 wt % hydrogen peroxide.

[0015] Furthermore, the pore size of the nylon membrane is 0.2 μm.

[0016] Furthermore, the preparation method of the dopamine-treated nylon membrane in the fifth step is:

[0017] S1: Add 0.1 mol / L hydrochloric acid solution to 85.3 mL of deionized water to make up to 100 mL;

[0018] S2: Add 0.6057 g of tris(hydroxymethyl)aminomethane to the solution of S1, and stir to make the solution evenly dispersed;

[0019] S3: Add 200 mg of dopamine hydrochloride into the evenly dispersed solution of S2 and fully dissolve it to prepare a dopamine solution;

[0020] S4: Soak the nylon membrane in the dopamine solution and shake it overnight on an oscillator at a shaking rate of 100 to 180 rad / min to fully treat the nylon membrane.

[0021] The present application also discloses a cobalt-nickel separation system based on oxidative coordination, which consists of a feed end solution, a discharge end solution and a separation membrane; the feed end solution is a nickel ammonia or cobalt ammonia solution, the discharge end solution is an ammonium chloride solution, the separation membrane is a reduced graphene oxide membrane, and the concentration of metal ions in the feed end solution is 0.01 to 0.5 mol / L.

[0022] The present application also discloses the application of a cobalt-nickel separation system based on oxidative coordination in ore smelting and purification, so as to achieve the selective extraction of nickel and the selective retention of cobalt.

[0023] Principle explanation: Using ammonia water and hydrogen peroxide as oxidative coordination agents, the cobalt-ammonia complex formed is significantly larger than the nickel-ammonia complex and carries a more positive charge, which amplifies the charge and size differences of the cobalt and nickel ions. The size effect of reduced graphene oxide can efficiently separate cobalt and nickel metals, thereby achieving the recycling and reuse of cobalt and nickel resources. Compared with the existing cobalt-nickel separation system, the cobalt-nickel separation system based on oxidative coordination prepared in this application has higher flux and selectivity and is environmentally friendly, and has good application prospects.

[0024] Beneficial effects:

[0025] 1. A method for constructing a cobalt-nickel separation system based on oxidative coordination. The raw materials required for this method, such as nickel salt, cobalt salt, ammonium chloride, ammonia water, hydrogen peroxide, etc., are all bulk commercial products with low cost;

[0026] 2. The construction method of the cobalt-nickel separation system based on oxidation coordination has a simple and safe preparation process and is easy to realize industrial production;

[0027] 3. The cobalt-nickel separation system based on oxidation coordination in the present application has high flux and good selectivity. Compared with conventional cobalt-nickel separation membranes, the cobalt-nickel separation system based on oxidation coordination provided in the present application has significantly improved selectivity;

[0028] 4. The reduced graphene oxide membrane for the cobalt-nickel separation system provided in this application has good stability, and the selectivity does not change significantly after ten cycles;

[0029] 5. The preparation method of the cobalt-nickel separation system provided in this application requires raw materials such as nickel salts and cobalt salts, which are all bulk commercial products with low cost;

[0030] 6. The method for constructing a cobalt-nickel separation system based on oxidative coordination provided in the present application has the advantages of simple and safe preparation process and is easy to achieve large-scale preparation.

[0031] 7. This application achieves a cobalt-nickel separation selectivity of nearly 40, achieving a separation performance far exceeding that of conventional diffusion systems, and provides a new idea for the recycling of cobalt and nickel resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 This is a schematic diagram of the cobalt-nickel separation system based on oxidative coordination in Example 1 of the present application;

[0033] Figure 2 This is a scanning electron microscope image of a cross section of the reduced graphene oxide film material in Example 1 of the present application;

[0034] Figure 3 The X-ray diffraction spectra before and after the separation experiment of the reduced graphene oxide membrane material in Example 1 of the present application;

[0035] Figure 4 This is a comparison chart of the separation performance of cobalt and nickel in different separation systems in Comparative Example 1 of the present application;

[0036] Figure 5 This is a performance comparison diagram of the cobalt-nickel separation system based on oxidation coordination in Comparative Example 2 of the present application applied to different metal ion concentrations;

[0037] Figure 6 This is a performance comparison of the cobalt-nickel separation system based on oxidative coordination in Comparative Example 3 of the present application when applied to different ammonium chloride concentrations. DETAILED DESCRIPTION

[0038] The following are only embodiments of the present invention, and are not intended to limit the scope of the present invention. The present invention can be implemented in different forms, and all contents made using the contents of the present invention specification are included in the scope of patent protection of the present invention. The embodiments are provided to make the contents disclosed in the present invention more thorough and comprehensive.

[0039] Unless otherwise specified, all numbers appearing in the specification and claims of this application, such as active components, temperature, time, pressure, etc., should not be understood as absolutely precise values. Due to the standard deviation of the measurement technology, the measured values ​​inevitably have certain experimental errors.

[0040] Unless otherwise specified, the raw materials and reagents in the examples of this application can be purchased through commercial channels. The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0041] Example 1

[0042] A method for constructing a cobalt-nickel separation system based on oxidative coordination, the method comprising the following steps:

[0043] The first step is to prepare a feed end solution: nickel salt or cobalt salt is dispersed in a mixed solution of ammonia water and hydrogen peroxide, and a 0.01-0.5 mol / L nickel ammonia or cobalt ammonia solution is prepared by ultrasonication for half an hour as a feed end solution; a mixed solution of ammonia water and hydrogen peroxide is prepared by uniformly mixing 20-25 mL of 25 wt% concentrated ammonia water and 0.01-5 mL of 30 wt% hydrogen peroxide;

[0044] The second step is to prepare a discharge end solution: ammonium chloride is dispersed in deionized water to obtain a 1 mol / L ammonium chloride solution as a discharge end solution;

[0045] The third step is to prepare a precursor solution: 0.6 mg of graphene oxide is added to 40 mL of deionized water according to a mass volume ratio to prepare a precursor solution;

[0046] Step 4: Dissolve 160 μL of concentrated ammonia water and 6 mg of glucose in the precursor solution prepared in the third step according to the mass volume ratio, heat in an oven at 80 to 120° C. for 30 to 60 minutes, and naturally cool to room temperature to obtain a reduced graphene oxide dispersion;

[0047] Step 5: Add 0.1 mol / L hydrochloric acid solution to 85.3 mL of deionized water to make up to 100 mL;

[0048] Step 6: Add 0.6057 g of tris(hydroxymethyl)aminomethane to the fixed volume solution of S1, and stir to make the solution evenly dispersed;

[0049] Step 7: Add 200 mg of dopamine hydrochloride into the evenly dispersed solution of S2 and fully dissolve it to prepare a dopamine solution;

[0050] Step 8: Soak the nylon membrane in the dopamine solution and shake it overnight on an oscillator at a shaking rate of 100 to 180 rad / min to fully treat the nylon membrane;

[0051] Step 9: The nylon membrane treated with dopamine in the eighth step is used as a substrate, and the obtained reduced graphene oxide dispersion is poured into the reduced graphene oxide dispersion for vacuum filtration for 1 to 3 days to obtain a reduced graphene oxide membrane; the pore size of the nylon membrane is 0.2 μm;

[0052] Step 10: Add a feed end solution to one end of the H-type electrolytic cell and add a discharge end solution to the other end, and separate the feed end solution and the discharge end solution with the prepared reduced graphene oxide membrane;

[0053] Step 11: Add magnets at both ends and stir at a speed of 500-600 rad / s for 1 hour. Driven by osmotic pressure, metal ions diffuse from the feed end to the discharge end.

[0054] Comparative Example 1

[0055] This comparative example uses two different solution systems as the cobalt-nickel separation system, specifically:

[0056] This comparative example is basically the same as Example 1, except that: the first solution system is a solution at the feed end using deionized water, and the solution at the discharge end using deionized water; the second solution system is a mixed solution of ammonia water and hydrogen peroxide for the feed end solution, and the solution at the discharge end using deionized water.

[0057] Comparative Example 2

[0058] This comparative example changes the metal ion concentration of the feed end solution, specifically:

[0059] This comparative example is basically the same as Example 1, except that 0.01 mol / L, 0.05 mol / L or 0.5 mol / L nickel ammonia or cobalt ammonia solution is used instead of 0.1 mol / L nickel ammonia or cobalt ammonia solution as the feed end solution.

[0060] Comparative Example 3

[0061] This comparative example changes the concentration of ammonium chloride in the solution at the discharge end, specifically:

[0062] This comparative example is basically the same as Example 1, except that 0.01 mol / L, 0.1 mol / L, 0.5 mol / L, 3 mol / L or 5 mol / L ammonium chloride solution is used instead of 1 mol / L ammonium chloride solution as the discharge end solution.

[0063] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with this technology to understand the contents of the present invention and implement them accordingly. They cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for constructing a cobalt-nickel separation system based on oxidative coordination, characterized in that: The construction method comprises the following steps: The first step is to prepare a feed end solution: nickel salt or cobalt salt is dispersed in a mixed solution of ammonia water and hydrogen peroxide, and a 0.01-0.5 mol / L nickel ammonia or cobalt ammonia solution is prepared by ultrasonication for half an hour as a feed end solution; The second step is to prepare a discharge end solution: ammonium chloride is dispersed in deionized water to obtain a 0.01-5 mol / L ammonium chloride solution as a discharge end solution; The third step is to prepare a precursor solution: 0.6 mg of graphene oxide is added to 40 mL of deionized water according to a mass volume ratio to prepare a precursor solution; Step 4: Dissolve 160 μL of concentrated ammonia water and 6 mg of glucose in the precursor solution prepared in the third step according to the mass volume ratio, heat in an oven at 80 to 120° C. for 30 to 60 minutes, and naturally cool to room temperature to obtain a reduced graphene oxide dispersion; Step 5: Using the dopamine-treated nylon membrane as a substrate, pouring the prepared reduced graphene oxide dispersion into the membrane and vacuum filtering for 1 to 3 days to obtain a reduced graphene oxide membrane; Step 6: Add a feed end solution to one end of the H-type electrolytic cell and add a discharge end solution to the other end, and separate the feed end solution and the discharge end solution with the prepared reduced graphene oxide membrane; Step 7: Add magnets at both ends and stir at a speed of 500-600 rad / s for 1 hour. Driven by osmotic pressure, metal ions diffuse from the feed end to the discharge end.

2. The method for constructing a cobalt-nickel separation system based on oxidative coordination according to claim 1, characterized in that: In the first step, the mixed solution of ammonia water and hydrogen peroxide is prepared by uniformly mixing 20-25 mL of 25 wt% concentrated ammonia water and 0.01-5 mL of 30 wt% hydrogen peroxide.

3. The method for constructing a cobalt-nickel separation system based on oxidative coordination according to claim 1, characterized in that: The pore size of the nylon membrane is 0.2 μm.

4. The method for constructing a cobalt-nickel separation system based on oxidative coordination according to claim 1, characterized in that: The preparation method of the dopamine-treated nylon membrane in the fifth step is: S1: Add 0.1 mol / L hydrochloric acid solution to 85.3 mL of deionized water to make up to 100 mL; S2: Add 0.6057 g of tris(hydroxymethyl)aminomethane to the solution of S1, and stir to make the solution evenly dispersed; S3: Add 200 mg of dopamine hydrochloride into the evenly dispersed solution of S2 and fully dissolve it to prepare a dopamine solution; S4: Soak the nylon membrane in the dopamine solution and shake it overnight on an oscillator at a shaking rate of 100 to 180 rad / min to fully treat the nylon membrane.

5. A cobalt-nickel separation system based on oxidation coordination obtained by the construction method according to any one of claims 1 to 3, characterized in that: The cobalt-nickel separation system based on oxidative coordination is composed of a feed end solution, a discharge end solution and a separation membrane; the feed end solution is a nickel ammonia or cobalt ammonia solution, the discharge end solution is an ammonium chloride solution, and the separation membrane is a reduced graphene oxide membrane. The concentration of the metal ions in the feed end solution is 0.01-0.5 mol / L.

6. Application of the cobalt-nickel separation system based on oxidation coordination according to claim 4 in ore smelting and purification, characterized in that: Achieve selective extraction of nickel and selective retention of cobalt.

Images