Method for preparing nano-aluminum lithium material and adsorbent by laminar plasma beam

Abstract

This invention discloses a method for preparing nano-aluminum-based lithium materials and adsorbents using laminar plasma beams, belonging to the field of lithium-ion adsorption technology. This invention provides a simple, relatively mild, and highly repeatable method for preparing nano-aluminum-based lithium materials and adsorbents using plasma beams. In this invention, aluminum hydroxide and lithium chloride are mixed in a molar ratio of 2:1 to 1.3, and then evaporated and condensed by a plasma beam in a sealed space protected by an inert gas to obtain nano-aluminum-based lithium materials. These materials are then granulated with resin to obtain the adsorbent. This invention uses the controllable laminar arc heat generated by the plasma beam as a heat source, achieving physical high-temperature vaporization and simultaneous rapid condensation to form Al(OH)₂. 3 The nanomaterials with uniformly distributed LiCl molecules maximize the specific surface area of ​​the aluminum-based lithium adsorbent, resulting in superior adsorption capacity. This invention is produced in a fully enclosed manner under normal pressure, offering advantages such as safety, zero emissions, energy saving, environmental protection, short process, and continuous, efficient, and stable preparation.

Description

Method for preparing nano-aluminum-based lithium materials and adsorbents using laminar flow plasma beam Technical Field

[0001] This invention belongs to the field of lithium adsorption technology, specifically relating to a method for preparing nano-aluminum-based lithium materials and adsorbents using laminar plasma beams. Background Technology

[0002] Lithium is the lightest metal in the world. Lithium compounds are widely used in glass, enamel, welding, and also as lubricants, adsorbents, and pharmaceuticals. Currently, metallic lithium is used in lithium batteries, high-strength lithium-aluminum alloys, and many other applications, leading to a growing global demand for lithium. However, the total global terrestrial lithium resources are far from meeting the projected market demand, while the total resources of seawater, brine, and well brine are enormous. Research on lithium extraction from salt lake brine in my country started relatively late and is still in the exploratory development stage. Currently, the known methods for lithium extraction from salt lake brine mainly include precipitation, solvent extraction, roasting, and adsorbent methods. Among these, the adsorbent method has significant advantages over other methods from both economic and environmental perspectives, especially for extracting lithium from low-grade brine. The key to this method is finding adsorbents with good adsorption selectivity, high recycling rate, and relatively low cost.

[0003] Adsorbents can be classified into organic and inorganic adsorbents. Organic adsorbents are generally organic ion exchange resins, such as IR-120B cation exchange resin. Inorganic ion exchange adsorbents have high selectivity for lithium, especially some special inorganic ion exchange adsorbents with ion sieving effects, which have become the most effective adsorbents for extracting useful elements from dilute solutions. Amorphous aluminum hydroxide adsorbents are considered one of the adsorbents with the best adsorption performance and application prospects. These adsorbents generally have different compositions, and different preparation methods can lead to significant differences in their adsorption performance and number of cycles.

[0004] CN202210212896.4 discloses a method for preparing lithium adsorbents by in-situ growth on alumina spheres, comprising the following steps: S1. Etching Al2O3 spheres with acid, then cleaning and drying; S2. Wetting the dried Al2O3 spheres with LiCl solution, then drying to obtain dry LiCl-Al2O3 spheres; S3. Wetting the dry LiCl-Al2O3 spheres with AlCl3 solution to obtain wet AlCl3-LiCl-Al2O3 spheres; S4. Wetting the wet AlCl3-LiCl-Al2O3 spheres with LiOH solution, then heating and reacting at 50-80℃ to obtain LiCl·Al2(OH)6·yH2O-Al2O3 spheres; S5. Placing the LiCl·Al2(OH)6·yH2O-Al2O3 spheres in LiCl solution and allowing them to stand to obtain Li...(1-x) Cl (1-x) ·Al2(OH)6·yH2O-Al2O3 spherical lithium adsorbent.

[0005] CN20221060638.5 discloses a high-mixing continuous rotary reactor and a method for preparing aluminum salt lithium adsorbents using the same, comprising the following steps: a) adjusting the high-mixing continuous rotary reactor to the required reaction gap using a gasket; b) introducing a pre-prepared lithium-aluminum mixed solution and an alkaline solution into the high-mixing continuous rotary reactor; c) controlling the reaction conditions to carry out the mixing reaction; d) after the reaction is completed, collecting the reaction mixture and aging and drying it to obtain the aluminum salt lithium adsorbent LiCl·mAl(OH)3·nH2O, where m is 2 to 10 and n is 0.5 to 10.

[0006] However, the two methods mentioned above are complex to operate, have low preparation efficiency, require water in the preparation process, resulting in water molecules in the obtained product, which affects product performance. Furthermore, the Li and Al raw materials cannot react completely, leading to significant waste and high production costs. Therefore, there is an urgent need to develop a new production route for aluminum-based lithium adsorbents that has the advantages of simple and flexible operation, short process, low investment, and good repeatability. Summary of the Invention

[0007] To address the problems existing in the preparation of nano-aluminum-based lithium adsorbents using current technologies, this invention first provides a method for preparing nano-aluminum-based lithium materials using laminar plasma beams, comprising the following steps:

[0008] The raw materials Al(OH)3 and LiCl are mixed evenly in a molar ratio of 2:1 to 1.3. Then, under the protection of inert gas, the mixed raw materials are sent into the reaction chamber by gas flow. The laminar plasma beam generated by the plasma generator in the reaction chamber is used as the heat source to make Al(OH)3 and LiCl undergo a high-temperature gasification reaction. After condensation and collection, nano-aluminum-based lithium materials are obtained.

[0009] In the above method for preparing nano-aluminum-based lithium materials using laminar plasma beams, the purity of Al(OH)3 is not less than 99.5%, and the particle size does not exceed 0.05 mm.

[0010] In the above method for preparing nano-aluminum lithium materials using laminar plasma beams, the purity of the LiCl is not less than 99.5%, and the particle size is not more than 0.05 mm.

[0011] In the above method for preparing nano-aluminum-based lithium materials using laminar plasma beams, the flow rate of the mixed raw materials fed into the reaction chamber via gas flow is 1 to 1.5 m / s.

[0012] In the above-mentioned method for preparing nano-aluminum-based lithium materials using laminar plasma beams, an inert gas at a temperature of 0–5°C is used to condense the material after the high-temperature gasification reaction.

[0013] In the above method for preparing nano-aluminum-based lithium materials using laminar plasma beams, the flow rate of the inert gas at a temperature of 0–5°C is 1–1.5 m / s.

[0014] In the above-mentioned method for preparing nano-aluminum-based lithium materials using laminar plasma beams, the resulting nano-aluminum-based lithium materials have a particle size of 20–100 nm and a specific surface area of ​​50–100 m². 2 / g.

[0015] The present invention also provides a method for preparing nano-aluminum-based lithium adsorbents using laminar flow plasma beams, which, based on the aforementioned method, further includes the following steps: uniformly mixing the obtained nano-aluminum-based lithium material with resin, granulating the mixture, and obtaining the nano-aluminum-based lithium adsorbent.

[0016] The beneficial effects of this invention are:

[0017] This invention utilizes laminar flow arc heating (a controllable high-temperature heat source generated by a plasma beam) as the heat source to prepare spherical nanomaterials with a particle size of 20–100 nm and a specific surface area of ​​50–100 m². 2 / g, and the resulting aluminum-based lithium adsorbent has excellent adsorption performance, with a lithium adsorption capacity of up to 12mg / g.

[0018] The entire process utilizes a unique laminar flow electric arc thermal plasma beam to generate a controllable high-temperature heat source, achieving physical high-temperature evaporation and rapid condensation simultaneously. This gives the entire production process advantages such as: normal pressure, fully enclosed operation, zero emissions, energy saving and environmental protection, short process flow, continuous preparation, high efficiency and stability. Attached Figure Description

[0019] Figure 1 is a schematic diagram of the process for preparing nano-aluminum-based lithium materials using laminar plasma beam according to the present invention.

[0020] Figure 2 is a scanning electron microscope image of the spherical nanoscale aluminum-based lithium material of Example 1. Detailed Implementation

[0021] Specifically, a method for preparing nano-aluminum-based lithium materials using laminar plasma beams includes the following steps:

[0022] The raw materials Al(OH)3 and LiCl are mixed evenly in a molar ratio of 2:1 to 1.3. Then, under the protection of inert gas, the mixed raw materials are sent into the reaction chamber by gas flow. The laminar plasma beam generated by the plasma generator in the reaction chamber is used as the heat source to make Al(OH)3 and LiCl undergo a high-temperature gasification reaction. After condensation and collection, nano-aluminum-based lithium materials are obtained.

[0023] Experiments revealed that plasma beams can be categorized into turbulent and laminar flows. Turbulent flows are characterized by high noise, large fluctuations, and significant axial temperature differences, resulting in large arc voltage fluctuations, energy spikes, and short equipment lifespan. In contrast, laminar flows exhibit low noise, stable parameters, small temperature gradients, and good repeatability. Utilizing the high-temperature laminar flow characteristics of plasma beams to prepare nano-aluminum-based lithium adsorbents offers advantages such as simple and flexible operation, short process flow, low investment, and good repeatability, thus demonstrating broad application prospects. Therefore, this invention employs laminar arc heat (a controllable high-temperature heat source generated by the plasma beam) as the heat source.

[0024] In this invention, the purity of Al(OH)3 is not less than 99.5% and the particle size is not more than 0.05 mm; the purity of LiCl is not less than 99.5% and the particle size is not more than 0.05 mm; the resulting nano-aluminum-based lithium material can achieve a purity of over 99.99% and has extremely low impurity content, which is beneficial to improving its adsorption performance.

[0025] In this invention, the mixed raw materials are fed into the reaction chamber by airflow at a velocity of 1 to 1.5 m / s. After gasification, the material after high-temperature gasification reaction is condensed by inert gas at a temperature of 0 to 5°C. The velocity of the inert gas at a temperature of 0 to 5°C is controlled at 1 to 1.5 m / s to achieve continuous production.

[0026] This invention strictly controls the molar ratio in advance and uses a laminar plasma beam to uniformly vaporize Al(OH)3 and LiCl at a molar ratio of 2:1 to 1.3. The raw materials react almost completely in the gaseous state, and then condense to form spherical nanomaterials with uniformly distributed Al(OH)3 and LiCl molecules, thus avoiding the problem of raw material waste. Since hollow spherical nanomaterials can be obtained, the specific surface area is maximized, which significantly improves the adsorption capacity of the material.

[0027] The present invention also provides a method for preparing nano-aluminum-based lithium adsorbents using laminar flow plasma beams, which, based on the aforementioned method, further includes the following steps: uniformly mixing the obtained nano-aluminum-based lithium material with resin, granulating the mixture, and obtaining the nano-aluminum-based lithium adsorbent.

[0028] In this invention, the resin can be a common polymer in the art, such as polystyrene resin or polyacrylate resin, and its dosage is controlled according to conventional requirements.

[0029] The present invention will be further described in detail below through embodiments, but the scope of protection of the present invention is not limited to the embodiments described herein.

[0030] In this embodiment, the laminar plasma beam used comprises two parts: a plasma power supply, which is a high-frequency inverter power module, model TCPS60KW, with a power of 60KW, manufactured by Sichuan Tiejian Technology Co., Ltd.; and a plasma beam generator, also manufactured by Sichuan Tiejian Technology Co., Ltd.

[0031] In the examples, the purity of Al(OH)3 is not less than 99.5% and the particle size is not more than 0.05 mm, and the purity of LiCl is not less than 99.5% and the particle size is not more than 0.05 mm.

[0032] Example 1

[0033] Al(OH)3 and LiCl were mixed uniformly in a stirrer at a molar ratio of 2:1.2 for 10 minutes. The mixture was then stored in a powder material container (vacuum-evacuated and nitrogen-protected) under nitrogen protection at room temperature. During operation, valves 2 and 3 were opened to feed the powder material into the nano-reaction chamber at a flow rate of 1 m / s. A plasma generator was installed at the front end of the nano-reaction chamber, and the plasma beam generator was externally powered. The laminar plasma beam generated by the plasma generator entered the nano-reaction chamber. The entire plasma generator and nano-reaction chamber were located within a sealed material collection container filled with protective gas. A low-temperature condensing protective gas (temperature 0–5℃) was introduced at the rear end of the nano-reaction chamber, and the flow rate of the low-temperature condensing gas was controlled at 1 m / s. The generated new material was cooled and collected to obtain spherical nanoscale aluminum-based lithium material with a yield of 100%. Analysis showed that the particle size was 20–100 nm and the specific surface area was 85–100 m² / s. 2 / g.

[0034] The obtained spherical nanomaterials and resin were mixed evenly and granulated to obtain an aluminum-based lithium adsorbent. The particle size was found to be less than 0.1 mm and the lithium adsorption capacity reached 12 mg / g.

[0035] Table 1. Impurities in Aluminum-based Lithium Adsorbents

[0036]

[0037]

Claims

1. A method for preparing nano-aluminum-based lithium materials using laminar flow plasma beam, characterized in that: Includes the following steps: The raw materials Al(OH)3 and LiCl are mixed evenly in a molar ratio of 2:1 to 1.

3. Then, under the protection of inert gas, the mixed raw materials are sent into the reaction chamber by gas flow. The laminar plasma beam generated by the plasma generator in the reaction chamber is used as the heat source to make Al(OH)3 and LiCl undergo a high-temperature gasification reaction. After condensation and collection, nano-aluminum-based lithium materials are obtained.

2. The method for preparing nano-aluminum-based lithium materials using laminar plasma beam according to claim 1, characterized in that: The purity of the Al(OH)3 is not less than 99.5%, and the particle size does not exceed 0.05 mm.

3. The method for preparing nano-aluminum-based lithium materials using laminar plasma beam according to claim 1, characterized in that: The purity of the LiCl is not less than 99.5%, and the particle size is not more than 0.05 mm.

4. The method for preparing nano-aluminum-based lithium materials using laminar plasma beam according to claim 1, characterized in that: The flow rate of the mixed raw materials into the reaction chamber via airflow is 1 to 1.5 m / s.

5. The method for preparing nano-aluminum-based lithium materials using laminar plasma beam according to claim 1, characterized in that: An inert gas at a temperature of 0–5°C is used to condense the material after the high-temperature gasification reaction.

6. The method for preparing nano-aluminum-based lithium materials using laminar plasma beam according to claim 5, characterized in that: The flow rate of the inert gas at a temperature of 0–5°C is 1–1.5 m / s.

7. The method for preparing nano-aluminum-based lithium materials using laminar plasma beams according to any one of claims 1 to 6, characterized in that: The obtained nano-aluminum-based lithium materials have a particle size of 20–100 nm and a specific surface area of ​​50–100 m². 2 / g.

8. A method for preparing nano-aluminum-based lithium adsorbents using laminar flow plasma beams, characterized in that: Based on any one of claims 1 to 7, the method further includes the following step: mixing the obtained nano-aluminum lithium material and resin evenly, and granulating the mixture to obtain a nano-aluminum lithium adsorbent.

Images