Method for extracting lithium by using lithium ion battery electrode material original halide

Abstract

The invention discloses a method for extracting lithium by using lithium ion battery electrode material original halide, which comprises the following steps: S01, mixing a lithium ion battery electrode material, water and a lithium removal agent according to a mass ratio of 1: (10-50): (0.1-5), reacting at 20-90 DEG C for 1-72 hours, and treating to obtain lithium-poor electrode powder I; s02, mixing the powder I, an activating agent and salt lake raw brine according to the mass ratio of 1: (0.1-15): (3-200), and reacting for 1-100 hours at the temperature of 5-80 DEG C to prepare a lithium-rich electrode material; and S03, the lithium-rich electrode material is subjected to lithium removal according to the step S01, a lithium-rich solution and a lithium-poor electrode material are obtained through separation, and the lithium-poor electrode material can be recycled in the step S02. According to the method, the ion screening characteristic of an electrode material crystal structure is creatively utilized, vacancy defects are formed through controllable lithium removal so as to enhance lithium ion adsorption kinetics, and meanwhile, a selective lithium transmission channel is constructed by means of transition metal valence regulation and control. Compared with a traditional process, efficient extraction of lithium resources is achieved. The process has the advantages of being environmentally friendly, low in cost and high in lithium adsorption efficiency, is suitable for the scene of extracting lithium from the salt lake original brine with different components, can promote directional migration and adsorption of lithium ions through the valence state regulation reaction of the electrode material, and provides an innovative technical scheme for extracting lithium from the salt lake original brine.

Description

Technical Field

[0001] This text relates to the technical field of lithium extraction from salt lakes, and specifically relates to a method for extracting lithium from raw brine using lithium-ion battery electrode materials. Background Art

[0003] Currently, more than 90% of the lithium extraction processes from salt lakes in China still rely on the "lithium extraction from old brine" technical route. That is, first, impurities such as 80%-90% of magnesium, calcium, etc. in the brine are removed through precipitation methods, etc., and after the magnesium-lithium ratio is significantly reduced from dozens or even hundreds of times that of the raw brine, an adsorbent is then used for lithium enrichment. The mainstream adsorbent in the industry is an aluminum-based adsorbent, which has defects such as low selectivity, easy dissolution and loss under acidic conditions, and low adsorption capacity. Among other adsorbents, titanium-based adsorbents have weak resistance to sulfate interference and a large amount of desorption wastewater, while manganese-based adsorbents face problems such as high dissolution loss rate in alkaline environments, slow adsorption kinetics, and easy introduction of impurities. Traditional adsorbents generally have common defects of poor tolerance to brine impurities and short cycle life, and the aluminum / titanium / manganese systems respectively face technical bottlenecks of low lithium-magnesium separation efficiency, high cost of high-salt wastewater treatment, and insufficient material stability.

[0004] More importantly, the current mainstream lithium extraction technology from salt lakes in China is mainly the lithium extraction from old brine technology. The production of old brine is severely limited by the potassium fertilizer production capacity of the salt lake. Therefore, the large-scale release of salt lake lithium resources depends on the breakthrough of the lithium extraction technology from raw brine of the salt lake. In recent years, the emerging direct lithium extraction from raw brine DLE technology has become the key research direction in the industry. Among them, a series of electrochemical lithium extraction technologies developed by the team of Zhao Zhongwei at Central South University (such as CN102049237A, CN113278820B, CN115818801B, CN119615286A) achieve selective capture of lithium ions in the raw brine of the salt lake by constructing an electric field to drive electrode materials (such as iron phosphate ion sieve, modified electrodes, etc.). Although this type of technology has achieved efficient separation of lithium in high magnesium-lithium ratio brine, its core relies on electrochemical processes such as electrodialysis devices, external circuit voltage regulation, or electrode polarity conversion, and there are problems such as high device construction cost (requiring supporting anion membranes, electrode components, and electric control systems) and high operating energy consumption (requiring continuous power supply to maintain the potential difference), making it difficult to adapt to large-scale industrial application scenarios. There is an urgent need to develop a new lithium extraction method with high selectivity, strong anti-interference ability, and can be mass-produced.

[0005] Therefore, the present invention has developed a method for extracting lithium from raw brine using lithium-ion battery electrode materials. By mixing the electrode material powder with an activator, the new lithium extraction method realizes efficient capture of lithium ions based on the valence state regulation mechanism, greatly simplifying the process flow compared with the electrochemical method. This technological breakthrough is expected to promote the large-scale application of the lithium extraction technology from raw brine, significantly reduce the carbon emissions generated in the pretreatment process, and provide a more economical and environmentally friendly solution for the development of salt lake lithium resources. Summary of the Invention

[0006] By using a new lithium extraction method, the electrode material powder is mixed with an activator, and based on the valence state regulation mechanism, efficient lithium ion capture is achieved, greatly simplifying the process flow compared with the electrochemical method. This technological breakthrough is expected to promote the large-scale application of the raw brine lithium extraction technology, significantly reduce the carbon emissions generated in the pretreatment process, and provide a more economical and efficient solution for the development of salt lake lithium resources.

[0007] To achieve the above invention purposes, the specific technical solutions of the present invention are as follows:

[0008] S01. Mix the lithium ion battery electrode material, water and delithiation agent in a certain mass ratio, react at a certain temperature, filter and dry to obtain the lithium-depleted electrode powder I;

[0009] S02. Mix the powder I, activator and raw brine of the salt lake in a certain mass ratio, react at a certain temperature, filter, dry and screen to obtain the lithium-rich electrode material adsorbed with lithium ions;

[0010] S03. Delithiate the lithium-rich electrode material according to S01, separate to obtain the lithium-rich solution and the lithium-depleted electrode material, and the lithium-depleted electrode material can be recycled to step S02.

[0011] For the method of extracting lithium from raw brine using a lithium ion battery electrode material as described above, preferably, the lithium ion battery electrode material, water and delithiation agent in step S01 are mixed in a mass ratio of 1:(10 - 50):(0.1 - 5), the reaction temperature is 20 - 90 °C, the reaction time is 1 - 72 h, and the screening mesh number is 80 - 300 meshes.

[0012] For the method of extracting lithium from raw brine using a lithium ion battery electrode material as described above, preferably, the lithium ion battery electrode material in step S01 is one or more of LiMn2O4, LiFePO4, LiMn X Fe 1-X PO4, LiVPO4F, Li 1.2 Mn 0.54 Ni 0.13 Co 0.13 O2, Li2TiO3, LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2, LiNi 0.6 Co 0.2 Mn 0.2 O2, LiNi 0.8 Co 0.1 Mn 0.1 O2, Li7Ti5O 12 and one or more of them.

[0013] A method for extracting lithium from raw brine of lithium-ion battery electrode materials as described above. Preferably, the delithiation agent in step S01 is one or a mixture of two or more of potassium permanganate, hydrogen peroxide, ozone, nitric acid, sodium peroxide, acetic acid, hypochlorous acid, sulfurous acid, sodium persulfate, hydrochloric acid, sulfuric acid, oxalic acid or potassium persulfate.

[0014] A method for extracting lithium from raw brine of lithium-ion battery electrode materials as described above. Preferably, the powder I in step S02, the activator and the raw brine of the salt lake are mixed according to a mass ratio of 1:(0.1 - 15):(3 - 200), the reaction temperature is 5 - 80°C, the reaction time is 1 - 100 h, and the mesh number of the activator is 50 - 300 mesh.

[0015] A method for extracting lithium from raw brine of lithium-ion battery electrode materials as described above. Preferably, the activator in step S02 is one or more of aluminum powder, chromium powder, copper powder, iron powder, lead powder, magnesium powder, nickel powder, tin powder, zinc powder, or a combined powder of two or more of the above metals. Description of the Drawings

[0016] Figure 1 It is a technical roadmap. Detailed Embodiments

[0017] The following examples are used to illustrate the present invention, but are not used to limit the scope of the present invention.

[0018] Example 1

[0019] Using LiNi 0.6 Co 0.2 Mn 0.2 O2, mix it with water and potassium permanganate according to a mass ratio of 1:50:0.5, react at 50°C for 6 h, filter, dry and then pass through a 180-mesh sieve to obtain the lithium-depleted electrode powder I. Sieve the zinc powder through 100 mesh, and mix the powder I, zinc powder and Dongtai raw brine according to a mass ratio of 1:8:150. The main components of this brine are shown in Table 1. React at 30°C for 60 h, and after treatment, obtain the lithium-rich electrode material. Tests show that the lithium ion adsorption capacity reaches 32.16 mg / g. Mix the obtained lithium-rich electrode material with water and potassium permanganate according to a mass ratio of 1:50:0.5 to obtain the lithium-depleted electrode material for cyclic lithium extraction. The lithium ion concentration of the obtained lithium-rich solution is 3 g / L, and carbon dioxide is introduced and purified to obtain lithium carbonate products. The product indexes meet the battery-grade lithium carbonate product standards.

[0020] Table 1 Main components of Dongtai raw brine (g / L)

[0021]

[0022] Example 2

[0023] Mix LiFePO4, water and sodium persulfate in a mass ratio of 1:33:1.19, react at 60 °C for 1 h, filter, dry, and then pass through a 200-mesh sieve to obtain the lithium-deficient electrode powder I. Pass aluminum powder through a 200-mesh sieve, take powder I, aluminum powder and Yiliping raw brine and mix them in a mass ratio of 1:0.2:100. The main components of this brine are shown in Table 2. React at 40 °C for 50 h, filter, dry, and then pass through a 150-mesh sieve to obtain the lithium-rich electrode material. After testing, the lithium ion adsorption capacity reaches 16.68 mg / g. Mix the obtained lithium-rich electrode material, water and sodium persulfate in a mass ratio of 1:33:1.19 to obtain the lithium-deficient electrode material for cyclic lithium extraction. The lithium ion concentration of the obtained lithium-rich solution is 1 g / L. Add sodium carbonate and purify to obtain lithium carbonate products, and the product indexes meet the battery-grade lithium carbonate product standards.

[0024] Table 2 Main components of Yiliping raw brine (g / L)

[0025]

[0026] Example 3

[0027] Take the lithium ion battery electrode material (LiMn2O4 and LiFePO4 are mixed in a ratio of 1:1), and mix it with water and the delithiation agent (a mixed solution of sulfuric acid and hydrogen peroxide, mass ratio 1:1) in a mass ratio of 1:40:2. React at 80 °C for 12 h, filter and dry, and then pass through a 250-mesh sieve to obtain the lithium-deficient electrode powder I. Pass magnesium powder through a 100-mesh sieve, and mix powder I, magnesium powder and Zabuye raw brine in a mass ratio of 1:3:80. The main components of this brine are shown in Table 3. React at 50 °C for 24 h, and process to obtain the lithium-rich electrode material. After measurement, the lithium ion adsorption capacity reaches 36.81 mg / g. Mix the obtained lithium-rich electrode material, water and the delithiation agent (a mixed solution of sulfuric acid and hydrogen peroxide, mass ratio 1:1) in a mass ratio of 1:40:2 to obtain the lithium-deficient electrode material for cyclic lithium extraction. The lithium ion concentration of the obtained lithium-rich solution is 5 g / L. Pass carbon dioxide and purify to obtain lithium carbonate products, and the product indexes meet the battery-grade lithium carbonate product standards.

[0028] Table 3 Main components of Zabuye raw brine (g / L)

[0029]

Claims

1. A method for extracting lithium from the original brine of lithium-ion battery electrode materials, characterized in that, The method includes the following steps: S01. Mix the lithium-ion battery electrode material, water, and delithiation agent in a certain mass ratio, react at a certain temperature, filter, and dry to obtain powder I of the lithium-depleted electrode; S02. Mix powder I, the activator, and the original brine of the salt lake in a certain mass ratio, react at a certain temperature, filter, and dry to obtain the lithium-rich electrode material that adsorbs lithium; S03. Delithiate the lithium-rich electrode material according to S01, separate to obtain a lithium-containing solution and a lithium-depleted electrode material, and the lithium-depleted electrode material can be returned to step S02 for recycling.

2. The method for extracting lithium from raw brine using lithium-ion battery electrode materials according to claim 1, characterized in that, In step S01, the lithium-ion battery electrode material, water, and delithiation agent are mixed in a mass ratio of 1:(10-50):(0.1-5), the reaction temperature is 20-90 °C, the reaction time is 1-72 h, and the mesh number of powder I for sieving is 80-300 meshes.

3. A method for extracting lithium from raw brine using lithium-ion battery electrode materials according to claim 1, characterized in that, The lithium-ion battery electrode material in the step S01 is one or more of LiMn2O4, LiFePO4, LiMn X Fe 1-X PO4, LiVPO4F, Li 1.2 Mn 0.54 Ni 0.13 Co 0.13 O2, Li2TiO3, LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2, LiNi 0.6 Co 0.2 Mn 0.2 O2, LiNi 0.8 Co 0.1 Mn 0.1 O2, Li7Ti5O 12 and the like.

4. A method for extracting lithium from raw brine using lithium-ion battery electrode materials according to claim 1, characterized in that, The delithiation agent in step S01 is one or two or more of potassium permanganate, hydrogen peroxide, ozone, nitric acid, sodium peroxide, acetic acid, hypochlorous acid, sulfurous acid, sodium persulfate, hydrochloric acid, sulfuric acid, oxalic acid, or potassium persulfate.

5. A method for extracting lithium from raw brine using lithium-ion battery electrode materials according to claim 1, characterized in that, In step S02, powder I, the activator, and the original brine of the salt lake are mixed in a mass ratio of 1:(0.1-15):(3-200), the reaction temperature is 5-80 °C, the reaction time is 1-100 h, and the mesh number of the activator is 50-300 meshes.

6. A method for extracting lithium from raw brine using lithium-ion battery electrode materials according to claim 1, characterized in that, The activator in step S02 is one or more of aluminum powder, chromium powder, copper powder, iron powder, lead powder, magnesium powder, nickel powder, tin powder, zinc powder, or a combination of alloy powders of two or more of the above metals.

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