Preparation method of copper-carbon composite material based on waste circuit board and low-rank coal

Abstract

The invention provides a preparation method of a copper-carbon composite material based on waste circuit boards and low-rank coal, and belongs to the technical field of solid waste resource utilization and environmental protection. The method comprises the following steps that waste circuit board powder and acid are mixed and then subjected to acid leaching, and acid leaching liquid is obtained; adjusting the pH of the pickle liquor to be alkaline, aging, and filtering to obtain copper oxide powder; and uniformly mixing the copper oxide powder with low-rank coal, and performing Joule flash evaporation treatment to obtain the copper-carbon composite material. According to the method, the preparation cost of the copper-carbon composite material is reduced, the two resources of the waste circuit board and the low-rank coal are fully utilized, remarkable economic and environment-friendly benefits are achieved, the conditions of the preparation method are green and mild, the steps are simple, the product stability is good, and large-scale production and application are facilitated.

Description

Technical Field

[0001] The invention relates to the technical field of solid waste resource utilization and environmental protection, and in particular to a method for preparing a copper-carbon composite material based on waste circuit boards and low-rank coal. Background Art

[0002] With the rapid development of electronic products, a large number of discarded electronic and electrical equipment have been generated in recent years. For all electronic devices, circuit boards are the most important component. Discarded circuit boards contain a variety of valuable metal elements, among which copper has the highest content, accounting for between 10% and 30%. As a key metal in electronic equipment, copper recycling is of great significance. In addition, discarded circuit boards also contain some harmful substances, such as tin, lead and brominated flame retardants. If these materials are not handled properly, they will cause serious pollution to the environment. Therefore, recycling metals in discarded circuit boards is not only an important challenge for environmental protection, but also an important opportunity for resource recycling.

[0003] Low-rank coal refers to coal with relatively low carbon content, usually including low-rank coal and sub-coal. Compared with high-rank coal, low-rank coal has lower calorific value, but its resource reserves are abundant and widely distributed around the world. Since low-rank coal contains more water and volatile matter, its calorific value and efficiency in energy utilization are relatively low. However, low-rank coal has unique potential in energy conversion, chemical preparation and environmental governance. In recent years, with the increase in energy demand and the improvement of environmental protection requirements, the efficient utilization of low-rank coal has gradually become a research hotspot. Especially in the fields of catalyst preparation and pollutant degradation, low-rank coal, as a cheap and abundant raw material, has great application prospects. The carbon content and structural characteristics of low-rank coal make it an ideal carrier material, and its surface activity and catalytic performance can be enhanced by different modification methods. Low-rank coal can not only be used as energy fuel, but also as an effective catalyst carrier for environmental governance such as water treatment and waste gas purification. However, the modification methods for enhancing the surface activity and catalytic performance of low-rank coal in the prior art have the disadvantages of complex processes and are difficult to achieve large-scale production and utilization. Summary of the invention

[0004] Based on the above content, the purpose of the present invention is to provide a method for preparing a copper-carbon composite material based on waste circuit boards and low-rank coal. The method provided by the present invention has a simple process and realizes efficient recycling and resource utilization of waste, thereby promoting green and sustainable development.

[0005] In order to achieve the above object, the present invention provides the following technical solutions:

[0006] One of the technical solutions of the present invention is a method for preparing a copper-carbon composite material based on waste circuit boards and low-rank coal, comprising the following steps:

[0007] Mixing the waste circuit board powder with acid and then performing acid leaching to obtain an acid leaching solution;

[0008] The pH of the acid leaching solution is adjusted to be alkaline, then aged, and then filtered to obtain copper oxide powder;

[0009] The copper oxide powder is uniformly mixed with low-rank coal and then subjected to Joule flash treatment to obtain a copper-carbon composite material.

[0010] The second technical solution of the present invention is a copper-carbon composite material prepared by the above preparation method.

[0011] A third technical solution of the present invention is an application of the copper-carbon composite material in catalytic degradation of tetracycline hydrochloride.

[0012] The present invention discloses the following technical effects:

[0013] (1) The present invention mainly utilizes copper derived from waste circuit boards and realizes the extraction of copper elements through a cyclic leaching method. This method cyclically leaches copper through a solvent, can efficiently extract copper and reduce the generation of harmful by-products, and provides a green and sustainable solution for copper recovery.

[0014] (2) The present invention uses low-rank coal as a carrier and adopts Joule flash evaporation technology to load copper elements onto the surface of the low-rank coal, and generates a copper-carbon composite material under high-temperature instantaneous heating conditions. The Joule flash evaporation technology achieves efficient combination of copper and carbon carriers through rapid heating by electric current, ensuring the uniform distribution of nano-copper particles.

[0015] (3) The Joule flash evaporation preparation method has controllable conditions, is fast, and has simple steps. It can efficiently synthesize carbon-loaded nanomaterials in a short time, has high production efficiency, and can meet the needs of large-scale production. Through this method, not only the preparation cost of copper-carbon composite materials is reduced, but also the two resources of waste circuit boards and low-rank coal are fully utilized, which has significant economic and environmental benefits. The preparation method is green, mild, simple, and has good product stability, which is conducive to large-scale production and application. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. 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 creative work.

[0017] Figure 1 is the XRD pattern of the copper oxide nanoparticles obtained in Examples 1-3;

[0018] Figure 2FTIR analysis chart of the copper-carbon composite material obtained in Example 1-3;

[0019] Figure 3 This is a scanning electron microscope analysis image of the copper-carbon composite material obtained in Example 1;

[0020] Figure 4 This is the XPS analysis diagram of the copper-carbon composite material obtained in Example 1, wherein (a) is Cu2p and (b) is O1s;

[0021] Figure 5 This is the XPS analysis diagram of the copper-carbon composite material obtained in Example 2, wherein (a) is Cu2p and (b) is O1s;

[0022] Figure 6 This is the XPS analysis diagram of the copper-carbon composite material obtained in Example 3, wherein (a) is Cu2p and (b) is O1s;

[0023] Figure 7 (a), (b) and (c) are respectively graphs showing the degradation rates of tetracycline hydrochloride by the copper-carbon composite materials obtained in Example 1, Example 2 and Example 3;

[0024] Figure 8 The present invention is a process flow chart for preparing a copper-carbon composite material based on waste circuit boards and low-rank coal;

[0025] Fig. 9 This is a cyclic stability diagram of the copper-carbon composite material obtained in Example 1 of the present invention. DETAILED DESCRIPTION

[0026] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but should be understood as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0027] It should be understood that the terms described in the present invention are only for describing a particular embodiment and are not intended to limit the present invention. In addition, for the numerical range in the present invention, it should be understood that each intermediate value between the upper and lower limits of the scope is also specifically disclosed. The intermediate value in any stated value or stated range, and each smaller range between any other stated value or intermediate value in the described range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0028] Unless otherwise indicated, all technical and scientific terms used herein have the same meanings as those generally understood by those skilled in the art. Although the present invention describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of a conflict with any incorporated document, the content of this specification shall prevail.

[0029] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments of the present invention description without departing from the scope or spirit of the present invention. Other embodiments derived from the present invention description will be apparent to the skilled artisan. The present invention description and examples are exemplary only.

[0030] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0031] Joule flash technology is a technology that heats materials through electric current, which can quickly reach high temperature and react in a very short time. The instantaneous high temperature and high pressure conditions make it possible to synthesize some materials that are difficult to synthesize under conventional methods, especially nanomaterials and metal composite materials. The present invention uses Joule flash technology to evenly disperse reactants on a nanoscale, synthesize materials with uniform particle size and high surface activity, and is suitable for the preparation of functional materials such as catalysts. The present invention uses Joule flash technology to prepare copper-carbon composite materials from copper and low-rank coal derived from waste circuit boards, which is of great significance. This not only effectively recovers copper in waste circuit boards and reduces environmental pollution, but also makes full use of low-rank coal resources. This method provides a new way for the recycling of waste resources and the development of copper-carbon composite materials, which meets the needs of green chemistry and sustainable development.

[0032] The first aspect of the present invention provides a method for preparing a copper-carbon composite material based on waste circuit boards and low-rank coal, comprising the following steps:

[0033] Mixing the waste circuit board powder with acid and then performing acid leaching to obtain an acid leaching solution;

[0034] The pH of the acid leaching solution is adjusted to be alkaline, then aged, and then filtered to obtain copper oxide powder;

[0035] The copper oxide powder is uniformly mixed with low-rank coal and then subjected to Joule flash treatment to obtain a copper-carbon composite material.

[0036] In some embodiments of the present invention, before acid leaching after mixing the waste circuit board powder with acid, the step of passing the waste circuit board powder through a 1 mm sieve is also included.

[0037] In some embodiments of the present invention, the acid is nitric acid; the concentration of the nitric acid is 3-4 mol / L; the acid leaching time is 12-24 h, and the number of acid leaching is 8-10 times.

[0038] In some embodiments of the present invention, the pH is 8.5-10.5; and the alkali solution used to adjust the pH is sodium hydroxide solution.

[0039] In some embodiments of the present invention, the concentration of the sodium hydroxide solution is 1-2 mol / L.

[0040] In some embodiments of the present invention, the aging temperature is 95-105° C. and the time is 4-7 hours.

[0041] In some embodiments of the present invention, the mass ratio of the copper oxide powder to low-rank coal is 1:2-1:6.

[0042] In some embodiments of the present invention, the Joule flash treatment is performed at a temperature of 1100° C. to 2100° C. and for a time of 10 s to 20 s.

[0043] A second aspect of the present invention provides a copper-carbon composite material prepared by the above preparation method.

[0044] The third aspect of the present invention provides an application of the copper-carbon composite material in catalytic degradation of tetracycline hydrochloride.

[0045] In some embodiments of the present invention, the dosage of the copper-carbon composite material is 0.2 g / L.

[0046] The technical solutions described in the present invention, unless otherwise specified, are all conventional solutions in the art, and the reagents or raw materials used, unless otherwise specified, are purchased from commercial channels or have been disclosed.

[0047] In order to better understand the present invention, the content of the present invention is further explained below in conjunction with the embodiments, but the content of the present invention is not limited to the following embodiments.

[0048] The industrial and elemental analysis of the low-rank coal in the embodiment is shown in Figure 1. The discarded circuit board is a discarded power bank motherboard, in which the copper content is higher than 17%, and the XRF analysis is shown in Figure 2.

[0049] Table 1

[0050]

[0051] Table 2

[0052]

[0053] Example 1

[0054] A method for preparing a copper-carbon composite material based on waste circuit boards and low-rank coal, comprising the following steps:

[0055] (1) placing waste circuit board powder in a nitric acid solution for cyclic leaching, the leaching time is 12 hours, the number of leaching times is 8 times; the nitric acid concentration is 4 mol / L, and after the reaction is completed, sodium hydroxide is added until the solution pH is 10.5; then the solution is aged in an oven at a temperature of 105° C. for 4 hours, and then filtered to obtain copper oxide nanoparticles;

[0056] (2) Ultrasonic mixing of copper oxide nanoparticles and low-rank coal in a mass ratio of 1:2, taking 0.7g of the mixture, placing it in a quartz tube with an inner diameter of 12mm, plugging both sides of the quartz tube with a diameter of 12mm, slowly compressing the quartz plug, and measuring the resistance of the sample until the resistance is about 2Ω, stopping the compression, closing the vacuum box, and using a vacuum pump to evacuate the air pressure in the vacuum box to 0.02 atmospheres. Set the flash temperature to 1100℃ and the flash time to 15s. After 20s of stage heating, the temperature reaches 1100℃ and lasts for 15s. After the flash is completed, wait for the sample to cool to room temperature, pour out the reacted powder in the quartz tube, which is the copper-carbon composite material (denoted as pch / hm-12-1100-15).

[0057] Example 2

[0058] A method for preparing a copper-carbon composite material based on waste circuit boards and low-rank coal, comprising the following steps:

[0059] (1) placing waste circuit board powder in a nitric acid solution for cyclic leaching, the leaching time is 12 hours, the number of leaching times is 8 times; the nitric acid concentration is 4 mol / L, and after the reaction is completed, sodium hydroxide is added until the solution pH is 10.5; then the solution is aged in an oven at a temperature of 105° C. for 4 hours, and then filtered to obtain copper oxide nanoparticles;

[0060] (2) Ultrasonic mixing of copper oxide nanoparticles and low-rank coal in a mass ratio of 1:2, taking 0.7 g of the mixture, placing it in a quartz tube with an inner diameter of 12 mm, plugging both sides of the quartz tube with a graphite plug of 12 mm in diameter, slowly compressing the quartz plug, and measuring the resistance of the sample until the resistance is about 2Ω, stopping the compression, closing the vacuum box, and using a vacuum pump to evacuate the air pressure in the vacuum box to 0.02 atmospheres. The flash evaporation temperature is set to 1600°C and the flash evaporation time is 15s. After a 20s stage heating, the temperature reaches 1600°C and lasts for 15s. After the flash evaporation is completed, wait for the sample to cool to room temperature, pour out the reacted powder in the quartz tube, which is the copper-carbon composite material (denoted as pch / hm-12-1600-15). (That is, the difference from Example 1 is that the flash evaporation temperature is 1600°C)

[0061] Example 3

[0062] A method for preparing a copper-carbon composite material based on waste circuit boards and low-rank coal, comprising the following steps:

[0063] (1) placing waste circuit board powder in a nitric acid solution for cyclic leaching, the leaching time is 12 hours, the number of leaching times is 8 times; the nitric acid concentration is 4 mol / L, and after the reaction is completed, sodium hydroxide is added until the solution pH is 10.5; then the solution is aged in an oven at a temperature of 105° C. for 4 hours, and then filtered to obtain copper oxide nanoparticles;

[0064] (2) Ultrasonic mixing of copper oxide nanoparticles and low-rank coal in a mass ratio of 1:2, taking 0.7 g of the mixture, placing it in a quartz tube with an inner diameter of 12 mm, plugging both sides of the quartz tube with a graphite plug of 12 mm in diameter, slowly compressing the quartz plug, and measuring the resistance of the sample until the resistance is about 2Ω, stopping the compression, closing the vacuum box, and using a vacuum pump to evacuate the air pressure in the vacuum box to 0.02 atmospheres. The flash evaporation temperature is set to 2100°C and the flash evaporation time is 15s. After a 20s stage heating, the temperature reaches 1100°C and lasts for 15s. After the flash evaporation is completed, wait for the sample to cool to room temperature, pour out the reacted powder in the quartz tube, which is the copper-carbon composite material (denoted as pch / hm-12-2100-15). (That is, the difference from Example 1 is that the flash evaporation temperature is 2100°C)

[0065] Effect verification

[0066] Figure 1This is the XRD diagram of the copper oxide nanoparticles obtained in Examples 1-3 (in the figure, pch / hm-12-1100-15 represents the copper oxide nanoparticles in Example 1, pch / hm-12-1600-15 represents the copper oxide nanoparticles in Example 2, and pch / hm-12-2100-15 represents the copper oxide nanoparticles in Example 3). It can be seen that the main component of the prepared copper oxide nanoparticles is Cu(0).

[0067] Figure 2 This is the FTIR analysis chart of the copper-carbon composite material obtained in Example 1-3. It can be seen that the main functional groups of the copper-carbon composite material are: -OH, CH, C=C and Cu-O-Cu.

[0068] Figure 3 This is a scanning electron microscope analysis diagram of the copper-carbon composite material obtained in Example 1. It can be seen that the surface of the copper-carbon composite material is rough and the nano copper particles are evenly distributed on the surface of the carbon element.

[0069] Figure 4 , 5 6 are XPS analysis diagrams of the copper-carbon composite material obtained in Examples 1-3. Figure 4-Figure 6 Cu2p( Figure 4-Figure 6 Figure (a)) and O1s( Figure 4-Figure 6 As can be seen from Figure (b) in the figure, Cu exists in the form of Cu(0) and there is a Cu-OC bond, which proves that the copper element is successfully loaded on the surface of the carbon material.

[0070] Figure 7 (a), (b) and (c) are respectively the degradation rate diagrams of tetracycline hydrochloride by the copper-carbon composite material obtained in Example 1, Example 2 and Example 3. It can be seen that the degradation rate of tetracycline hydrochloride reaches more than 90% in 60 minutes (90% in Example 1, 91% in Example 2, and 92% in Example 3), which proves that the prepared material has good catalytic performance. The experimental parameters are tetracycline hydrochloride: 30 mg / L; catalyst dosage: 0.2 g / L; PMS dosage: 0.3 g / L; ph = 6.3; shaking table speed: 150 rpm; temperature: 25 ° C.

[0071] Fig. 9 The cyclic stability effect of the catalyst is demonstrated. As shown in the figure, after 5 cycles, the degradation rate of tetracycline hydrochloride by the catalyst can reach 82% within 60 minutes, proving that the prepared material has good stability.

[0072] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for preparing a copper-carbon composite material based on waste circuit boards and low-rank coal, characterized in that: The following steps are involved: Mixing the waste circuit board powder with acid and then performing acid leaching to obtain an acid leaching solution; The pH of the acid leaching solution is adjusted to be alkaline, then aged, and then filtered to obtain copper oxide powder; The copper oxide powder is uniformly mixed with low-rank coal and then subjected to Joule flash treatment to obtain a copper-carbon composite material.

2. The method for preparing a copper-carbon composite material based on waste circuit boards and low-rank coal according to claim 1, characterized in that: The acid is nitric acid; the concentration of the nitric acid is 3-4 mol / L; the acid leaching time is 12h-24h, and the number of acid leaching is 8-10 times.

3. The method for preparing the copper-carbon composite material based on waste circuit boards and low-rank coal according to claim 1, characterized in that: The pH value is 8.5-10.5; the alkali solution used to adjust the pH value is sodium hydroxide solution.

4. The method for preparing a copper-carbon composite material based on waste circuit boards and low-rank coal according to claim 1, characterized in that: The aging temperature is 95-105° C. and the aging time is 4-7 hours.

5. The method for preparing the copper-carbon composite material based on waste circuit boards and low-rank coal according to claim 1, characterized in that: The mass ratio of the copper oxide powder to the low-rank coal is 1:2-1:

6.

6. The method for preparing the copper-carbon composite material based on waste circuit boards and low-rank coal according to claim 1, characterized in that: The Joule flash treatment is performed at a temperature of 1100° C. to 2100° C. and for a time of 10 s to 20 s.

7. A copper-carbon composite material prepared by the preparation method according to any one of claims 1 to 6.

8. Use of the copper-carbon composite material according to claim 7 in catalytic degradation of tetracycline hydrochloride.

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