A method for preparing aluminum powder using waste aluminum-plastic composites

Abstract

This invention belongs to the field of aluminum powder preparation technology, and relates to a method for preparing aluminum powder from waste aluminum-plastic composites. The addition of fatty alcohol polyoxyethylene ether in this invention causes bubble collapse during the aluminum-plastic separation process. After distributing on the bubble surface, it attracts the hydrophobic end of a quaternary ammonium cationic surfactant, making it hydrophilic and allowing it to enter the aqueous phase, thus achieving a defoaming effect. This invention utilizes the quaternary ammonium cationic surfactant, through adsorption bridging and adsorption charge neutralization, to destabilize the dye molecules in the aluminum-plastic composite and separate them from water, thereby achieving a decolorization effect on the dye molecules on the plastic surface and significantly reducing the impurity content on the separated aluminum-plastic surface. This invention's recycling and preparation method is simple, with minimal aluminum powder loss, and is suitable for large-scale environmentally friendly industrial production.

Description

Technical Field

[0001] This invention belongs to the field of aluminum powder preparation technology, and relates to a method for preparing aluminum powder using waste aluminum-plastic composites. Background Technology

[0002] With my country's rapid economic development and accelerating industrialization and urbanization, resource consumption has increased year by year, leading to growing environmental pressures and resource bottlenecks. In recent years, the consumption of paper-plastic-aluminum composite packaging has gradually increased, and its proportion in urban solid waste has become increasingly larger.

[0003] Because paper-plastic-aluminum composite packaging is still mixed in with household waste and is difficult to classify and recycle separately, a complete waste classification mechanism has not yet been established in China. The raw materials of paper-plastic-aluminum are long-fiber pulp, polyethylene and high-quality aluminum foil, which have good recycling value after one use. At present, the alkaline solution immersion method is commonly used in the aluminum powder recycling process. The aluminum-plastic film is immersed in alkaline solution and drained. The aluminum foil and alkaline solution react fully to generate aluminum salts. Some of the aluminum salts remain in the alkaline solution, while the rest remain on the plastic, resulting in a relatively serious loss of aluminum. Summary of the Invention

[0004] The purpose of this invention is to address the aforementioned problems in the existing technology by proposing an environmentally friendly and efficient method for preparing aluminum powder from waste aluminum-plastic composites.

[0005] The objective of this invention can be achieved through the following technical solution: a method for preparing aluminum powder using waste aluminum-plastic composite, the method comprising the following steps: preheating the waste aluminum-plastic composite while introducing softening gas, then adding an aluminum-plastic separator and stirring evenly, then separating the aluminum and plastic, then centrifuging and crushing, washing with diluted aluminum-plastic separator, and finally washing with deionized water to obtain aluminum powder.

[0006] In the above-mentioned method for preparing aluminum powder using waste aluminum-plastic composite, the preheating temperature is 100-120℃ and the time is 3-5h.

[0007] In the above-mentioned method for preparing aluminum powder using waste aluminum-plastic composite, the softening gas is water vapor.

[0008] In the above-mentioned method for preparing aluminum powder using waste aluminum-plastic composite, the mass ratio of waste aluminum-plastic composite to aluminum-plastic separator is (3-5):1.

[0009] The present invention also provides an aluminum-plastic separator, wherein the aluminum-plastic separator comprises the following raw materials in the indicated mass fractions: 50-80 parts sodium bicarbonate, 15-18 parts sodium percarbonate, 20-30 parts ethanol, 8-10 parts fatty alcohol polyoxyethylene ether, 5-8 parts bleaching agent, 0.05-0.1 parts quaternary ammonium cationic surfactant, and 100-150 parts water.

[0010] The addition of fatty alcohol polyoxyethylene ether in this invention causes bubble collapse during aluminum-plastic separation. After distributing on the bubble surface, it attracts the hydrophobic end of the quaternary ammonium cationic surfactant, making it hydrophilic and allowing it to enter the aqueous phase, thus achieving a defoaming effect. Simultaneously, the ether bonds in the fatty alcohol polyoxyethylene ether are not easily destroyed by acids or alkalis, exhibiting high stability and easy biodegradability, without causing additional pollution.

[0011] In one of the aluminum-plastic separators mentioned above, the pH value of the aluminum-plastic separator is 7.5-8.

[0012] In one of the aluminum-plastic separators mentioned above, the bleaching agent is sodium perborate.

[0013] In the above-mentioned method for preparing aluminum powder using waste aluminum-plastic composite, the diluted aluminum-plastic separator is water and aluminum-plastic separator in a mass ratio of (3-5):1.

[0014] Compared with existing technologies, this invention has the following beneficial effects: The addition of fatty alcohol polyoxyethylene ether in this invention causes bubble collapse during aluminum-plastic separation. After distributing on the bubble surface, it attracts the hydrophobic end of the quaternary ammonium cationic surfactant, making it hydrophilic and allowing it to enter the aqueous phase, thus achieving a defoaming effect. This invention utilizes the quaternary ammonium cationic surfactant, through adsorption bridging and adsorption charge neutralization, to destabilize the dye molecules in the aluminum-plastic composite and separate them from water, thereby achieving a decolorization effect on the dye molecules on the plastic surface and significantly reducing the impurity content on the separated aluminum-plastic surface. The preparation method of this invention is simple, with low aluminum powder loss, making it suitable for large-scale environmentally friendly industrial production. Detailed Implementation

[0015] The following are specific embodiments of the present invention, which further describe the technical solution of the present invention, but the present invention is not limited to these embodiments.

[0016] Example 1:

[0017] 480 kg of waste aluminum-plastic composite was preheated at 120°C for 5 hours while steam was introduced. Then, a separating agent was added at a mass ratio of 4:1 and stirred evenly. Aluminum-plastic separation was then performed, followed by centrifugation. The aluminum powder was obtained by washing with diluted aluminum-plastic separating agent and then with deionized water.

[0018] The separating agent is composed of the following raw materials in parts by weight: 60 parts sodium bicarbonate, 16 parts sodium percarbonate, 25 parts ethanol, 8 parts fatty alcohol polyoxyethylene ether, 6 parts sodium perborate, 0.08 parts quaternary ammonium cationic surfactant, and 120 parts water.

[0019] The diluted aluminum-plastic separator is water and aluminum-plastic separator in a mass ratio of 4:1.

[0020] Example 2:

[0021] 480 kg of waste aluminum-plastic composite was preheated at 120°C for 5 hours while steam was introduced. Then, a separating agent was added at a mass ratio of 4:1 and stirred evenly. Aluminum-plastic separation was then performed, followed by centrifugation. The aluminum powder was obtained by washing with diluted aluminum-plastic separating agent and then with deionized water.

[0022] The separating agent is composed of the following raw materials in parts by weight: 50 parts sodium bicarbonate, 15 parts sodium percarbonate, 20 parts ethanol, 8 parts fatty alcohol polyoxyethylene ether, 5 parts sodium perborate, 0.05 parts quaternary ammonium cationic surfactant, and 100 parts water.

[0023] The diluted aluminum-plastic separator is water and aluminum-plastic separator in a mass ratio of 4:1.

[0024] Example 3:

[0025] 480 kg of waste aluminum-plastic composite was preheated at 120°C for 5 hours while steam was introduced. Then, a separating agent was added at a mass ratio of 4:1 and stirred evenly. Aluminum-plastic separation was then performed, followed by centrifugation. The aluminum powder was obtained by washing with diluted aluminum-plastic separating agent and then with deionized water.

[0026] The separating agent is composed of the following raw materials in parts by weight: 80 parts sodium bicarbonate, 18 parts sodium percarbonate, 30 parts ethanol, 10 parts fatty alcohol polyoxyethylene ether, 8 parts sodium perborate, 0.1 parts quaternary ammonium cationic surfactant, and 150 parts water.

[0027] The diluted aluminum-plastic separator is water and aluminum-plastic separator in a mass ratio of 4:1.

[0028] Comparative Example 1:

[0029] The only difference from Example 1 is that water vapor was not introduced.

[0030] Comparative Example 2:

[0031] The only difference from Example 1 is that diluted aluminum-plastic separator was not used for washing.

[0032] Table 1: Results of aluminum-plastic separation in Examples 1-3

[0033]

[0034] In summary, the addition of fatty alcohol polyoxyethylene ether in this invention causes bubble collapse during the aluminum-plastic separation process. After distributing on the bubble surface, it attracts the hydrophobic end of the quaternary ammonium cationic surfactant, making it hydrophilic and allowing it to enter the aqueous phase, thus achieving a defoaming effect. Simultaneously, the ether bonds in the fatty alcohol polyoxyethylene ether are not easily destroyed by acids or alkalis, exhibiting high stability and easy biodegradability without causing additional pollution. This invention utilizes the adsorption bridging and adsorption charge neutralization effects of the quaternary ammonium cationic surfactant to destabilize dye molecules and separate them from water, thereby achieving a decolorization effect on the dye molecules on the plastic surface and significantly reducing the impurity content on the separated aluminum-plastic surface.

[0035] The embodiments described herein cover any points not exhaustively within the scope of the technical claims of this invention, as well as new technical solutions formed by equivalent substitutions of one or more technical features in the embodiments. These are all within the scope of the claims of this invention. Furthermore, in all listed or unlisted embodiments of this invention, each parameter in the same embodiment merely represents an instance (i.e., a feasible solution) of its technical solution, and there is no strict coordination or limitation relationship between the parameters. The parameters can be substituted for each other without violating axioms and the claims of this invention, unless otherwise stated.

[0036] The technical means disclosed in this invention are not limited to those described above, but also include technical solutions composed of any combination of the above technical features. The above descriptions are specific embodiments of this invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of this invention, and these improvements and modifications are also considered within the scope of protection of this invention.

[0037] The specific embodiments described herein are merely illustrative of the spirit of the invention. Those skilled in the art to which this invention pertains may make various modifications or additions to the described specific embodiments or use similar methods to substitute them, without departing from the spirit of the invention or exceeding the scope defined by the appended claims.

Claims

1. A method for producing aluminum powder using waste aluminum laminate, characterized by, The method comprises the following steps: preheating the waste aluminum plastic composite, while softening gas is introduced, then adding aluminum plastic separating agent for uniform stirring, then aluminum plastic separation, then centrifugal crushing, washing with diluted aluminum plastic separating agent, and finally washing with deionized water to obtain aluminum powder; The aluminum plastic separating agent comprises the following raw materials in mass fraction: 50-80 parts of sodium bicarbonate, 15-18 parts of sodium percarbonate, 20-30 parts of ethanol, 8-10 parts of fatty alcohol polyoxyethylene ether, 5-8 parts of bleaching agent, 0.05-0.1 parts of quaternary ammonium cationic surfactant, and 100-150 parts of water; The pH of the aluminum plastic separating agent is 7.5-8. The bleaching agent is sodium perborate. The diluted aluminum plastic separating agent is water and aluminum plastic separating agent with a mass ratio of (3-5):

1.

2. The method of claim 1, wherein the aluminum powder is prepared by using the waste aluminum-plastic composite. The preheating temperature is 100-120℃, and the time is 3-5h.

3. The method of claim 1, wherein the aluminum powder is prepared by using the waste aluminum-plastic composite. The softening gas is water vapor.

4. The method of claim 1, wherein the aluminum powder is prepared by using the waste aluminum-plastic composite. The mass ratio of the waste aluminum plastic composite to the aluminum plastic separating agent is (3-5):1.

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