Low-temperature cracking treatment method for copper-containing sludge synergistic resin waste

Abstract

The invention belongs to the field of sludge treatment, and provides a low-temperature cracking treatment method for copper-containing sludge synergistic resin waste. The method comprises the following steps: firstly, pretreating the copper-containing sludge to remove volatile organic compounds and moisture in the sludge and increase the exposure degree of metal oxides so as to improve the reaction activity of the copper-containing sludge; then, the resin waste is subjected to pre-degassing treatment and swelling treatment, gas and volatile substances in the resin waste are removed, part of cross-linked structures of the resin waste are destroyed, the interaction force between resin chains is reduced, the subsequent cracking efficiency is improved, and the cracking reaction performance of the resin waste is optimized. In the cracking process, the copper-containing sludge serving as a catalyst and the resin waste are subjected to low-temperature cracking synergistically, through the catalytic action of active sites on the surface of metal oxide, the cracking reaction of organic molecules is accelerated, available gas is generated, meanwhile, copper reduction is achieved, the copper-containing sludge and the resin waste can be effectively treated, and through catalytic resin cracking, the copper-containing sludge and the resin waste can be recycled. And the resource utilization rate of wastes is improved.

Description

Technical Field

[0001] The invention belongs to the field of sludge treatment and relates to a method for treating copper-containing sludge by coordinating low-temperature cracking of resin waste. Background Art

[0002] Copper-containing sludge mainly comes from wastewater treatment residues in industrial processes such as electroplating, electronic manufacturing, and metallurgy. This type of sludge not only contains high concentrations of copper, but is also accompanied by organic matter, suspended matter, a small amount of inorganic salts, etc. The treatment of copper-containing sludge usually involves complex process flows and is costly. For example, the acid leaching process not only requires a large amount of chemical reagents, but also requires subsequent treatment of the waste liquid, which increases the treatment cost. At the same time, although incineration can effectively reduce the volume of sludge, it has high energy consumption, and the reaction of copper with other impurities under high temperature conditions will affect the recovery efficiency. In addition, toxic byproducts that may be produced during the treatment process, such as flue gas and residues, require additional purification and treatment equipment, which further increases the economic burden of the overall treatment.

[0003] Epoxy resin is a thermosetting polymer with excellent mechanical properties and chemical stability. It is usually used with reinforcing components (including metal, ceramic, glass or carbon fiber) to manufacture composite materials for various fields such as aerospace, shipbuilding, automobiles, electronics, wind power generation, etc. In industrial applications, epoxy resin is cured with a hardener to form a cross-linked network structure with excellent resistance to cyclic deformation or fatigue damage. However, the cross-linked epoxy resin polymer is quite stable, so the scrapping of epoxy resin-based composite materials has become a pressing issue. In the mechanical recycling process, the resin-based composite material is ground and screened, but the cross-linked chemical structure inside the epoxy resin polymer is not destroyed during the mechanical recycling process, so the purity of the recycled epoxy resin is usually poor, which inhibits the secondary use of epoxy resin. Chemical recycling uses various chemical agents to destroy the cross-linked structure of epoxy resin. Although recycling brings about the complete degradation of epoxy resin polymer, there are a series of problems such as long operating time and waste liquid pollution. In order to completely destroy the stable cross-linked network structure of epoxy resin polymer, the pyrolysis temperature of epoxy resin is usually as high as 500-600℃, which requires a lot of energy. Therefore, there is an urgent need for a method for low-temperature cracking of copper-containing sludge and resin waste to solve the problem of high energy consumption and the need for separate treatment of copper-containing sludge and resin waste under low energy consumption conditions. Summary of the invention

[0004] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a method for low-temperature pyrolysis of copper-containing sludge in conjunction with resin waste. In view of the complex composition of the copper-containing sludge, volatile organic matter is removed through pre-oxidation treatment to increase the exposure of metal oxides; the resin waste is pulverized and pre-degassed to help remove internal volatile components and reduce the generation of harmful gases during the pyrolysis process, and then immersed in acetic acid solution for swelling treatment, so that it is easier to decompose during the low-temperature pyrolysis process, thereby meeting the needs of actual production.

[0005] To achieve this object, the present invention adopts the following technical solutions:

[0006] In a first aspect, the present invention provides a method for low-temperature pyrolysis of copper-containing sludge in combination with resin waste, the method comprising:

[0007] Step S1, placing the copper-containing sludge in a hot air dryer, fully drying it at a first temperature, screening the dried sludge with a screen after the moisture content drops below a target moisture content, and then heating it to a second temperature for pre-oxidation treatment to obtain pre-treated copper-containing sludge;

[0008] Step S2, crushing the resin waste to a target particle size, then raising the temperature to a third temperature for pre-degassing treatment, immersing in an acetic acid solution for swelling treatment after the pre-degassing treatment, and filtering to obtain pre-treated resin waste;

[0009] Step S3, mixing the pretreated copper-containing sludge and the pretreated resin waste evenly and placing them at a fourth temperature for cracking reaction, maintaining a nitrogen atmosphere, and connecting a gas collection device and a condensation system to collect cracking products.

[0010] In the pretreatment process of copper-containing sludge, pre-oxidation treatment is an important step, which aims to create favorable conditions for subsequent low-temperature cracking and copper reduction recovery: copper-containing sludge usually contains a variety of organic matter. Through heat treatment in an air atmosphere, these organic matter will undergo decomposition and oxidation reactions. The organic matter in the sludge is converted into carbon dioxide and water under the action of oxygen. This process not only effectively reduces the content of organic pollutants in the sludge, but also avoids the problem of toxic gases generated by the cracking of organic matter in the subsequent cracking process. At the same time, at the pre-oxidation temperature, most volatile organic compounds (VOCs) can be completely oxidized to harmless gases and escape, reducing the generation of harmful substances in the subsequent cracking process. This also allows the inorganic components of the sludge, such as copper oxides, to be better exposed, which is convenient for subsequent metal treatment. Sludge usually contains a large amount of water, both free water and bound water. By heating, free water is first removed, and then bound water is removed at high temperature. The removal of bound water can reduce the water content in the sludge, increase the proportion of solid phase matter, and thus improve the density and reactivity of the sludge. The removal of bound water can also prevent the sludge from producing too much water vapor during the cracking process, thereby reducing energy consumption. The entire process is heated to evaporate water, and the inorganic components in the sludge are further concentrated, which is conducive to enhancing the reactivity of the sludge in subsequent cracking and reduction.

[0011] In the sludge pretreatment process, the core of pre-oxidation is to fully expose the metal components, especially copper oxides. Copper usually exists in the form of divalent copper ions, copper hydroxide or its complexes in sludge. It is converted into copper oxide through heating dehydration and oxidation reaction, which also increases the exposed surface area of ​​metal oxides in the sludge. Copper oxide, as a highly chemically active compound, can participate in redox reactions in the subsequent low-temperature cracking process and be reduced to metallic copper. Another important function of the pre-oxidation process is to remove other impurities in the sludge and prevent impurities from forming compounds with metal oxides that are not conducive to the reaction, thereby affecting the recovery rate of copper. The formation and exposure of copper oxide lays the foundation for the reduction reaction in the cracking process. After pre-oxidation treatment, the exposure and dispersion of metal oxides in the sludge, such as copper oxide, are significantly improved, making the copper in the sludge easier to be reduced during the cracking process. In addition, during the cracking process, copper oxide can also act as a catalyst to promote the cracking reaction of organic matter and produce a more efficient reaction environment. During the cracking process, copper oxide can react with the reducing gas (carbon monoxide or hydrogen) produced by cracking and eventually be reduced to metallic copper. Through this series of redox reactions, the copper in the sludge is effectively reduced to metallic copper, thereby achieving recovery. Pre-oxidation treatment not only provides a basis for copper recovery, but also reduces the generation of harmful gases and improves the environment of the cracking reaction by removing volatile organic matter and moisture in the sludge.

[0012] Pre-degassing is a key step in the pretreatment of resin waste. Its main purpose is to remove the volatile components remaining in the resin, preliminarily degrade some unstable chemical structures, and provide purer and more reactive raw materials for subsequent low-temperature cracking: Resin waste may contain some low-molecular-weight volatile organic compounds, including unreacted monomers (such as epoxy monomers or curing agent residues in epoxy resins), oligomers or incompletely reacted short-chain polymers, and residual solvents or additives in the process (such as plasticizers and stabilizers). When heated, these volatile organic compounds will evaporate or thermally decompose and escape from the waste system. At the same time, low-boiling point substances in the resin, such as solvents and small molecular monomers, will undergo phase change, from liquid or solid to gas, and then escape from the resin waste. Some unstable oligomers or monomers will undergo thermal decomposition reactions to generate smaller molecules.

[0013] During the pre-degassing process, the functional groups in the resin will begin to partially degrade or break, and some thermally unstable chemical bonds will undergo thermal cracking reactions at this temperature. The ester bonds in the resin waste may crack to generate carboxylic acids and alcohol compounds. The breakage of some polymer chains in the resin generates low molecular weight cracking products, which helps to reduce the decomposition temperature of the resin waste and promotes its easier breakage in the subsequent cracking process; the ether bonds contained in the resin are easy to break to generate alcohol compounds, which reduces the complexity of the resin molecular chain. The occurrence of this reaction also provides more reaction sites for the subsequent cracking of the resin and promotes further cracking of the macromolecular polymer chain at low temperature. During the pre-degassing process, the energy inside the resin molecular chain increases, the chain segments begin to move thermally, the polymer chain relaxes, the rigidity of the molecular chain decreases, and the structure gradually tends to loosen. The cross-linking bonds of the resin relax or break, although it will not completely destroy the three-dimensional network structure of the resin, but it will partially soften it, reducing the energy requirements in the subsequent cracking process. The temperature rise enhances the movement of the polymer molecular chain and increases the distance between the molecular chains. This relaxation effect can improve the cracking reactivity of the resin.

[0014] The purpose of immersing the resin waste in an acetic acid solution for swelling treatment is to make the resin structure looser. Most resins are three-dimensional cross-linked polymer networks. The swelling treatment will cause the solvent molecules to penetrate into the molecular gaps of the resin, causing its volume to expand and soften, thereby destroying part of its cross-linked structure. Acetic acid can diffuse into the gaps in the resin structure through molecules, resulting in a weakening of the interaction force between the resin chains, an increase in the distance between the resin molecular chains, a decrease in the rigidity of the cross-linked network, and the destruction of some cross-linked bonds. The chemical bonds in the resin are more easily broken under high temperature conditions, which reduces the decomposition temperature of the resin and improves the efficiency of subsequent cracking.

[0015] During the synergistic cracking process, there is a chemical interaction between the thermal cracking products of resin waste and the metal oxides in the copper-containing sludge. The reducing gas produced during the resin cracking process can effectively reduce the metal oxides to metallic copper, which not only recovers the metal, but also reduces the cracking temperature to a certain extent, so that the reaction can be carried out at a lower temperature and reduce energy consumption. The carbon monoxide produced by resin cracking reacts with the copper oxide in the sludge to produce metallic copper and carbon dioxide. Similarly, the hydrogen produced by cracking can also react with copper oxide to produce metallic copper and water, which not only reduces the copper oxide, but also reduces the accumulation of combustible gases such as carbon monoxide and hydrogen during the cracking process, effectively reducing safety risks; metal oxides have a catalytic effect in the cracking reaction. Metal oxides can catalyze the breaking of carbon-carbon bonds in resin cracking, promote more thorough decomposition of organic matter, and generate more small molecular products such as olefins, alkanes and aromatics. In the crystal structure of metal oxides, since oxygen and metal ions are in an incompletely coordinated state on the surface, they have unsaturated chemical bonds. These unsaturated bonds or coordinated unsaturated sites can form strong chemical adsorption with reactant molecules, which are called surface active sites. At these sites, the surface atoms of the metal oxide have higher chemical activity and can react with the incoming reactants. These surface active sites provide key reaction areas for the cracking reaction, allowing the organic molecules to be activated on the surface, thereby reducing the reaction energy barrier and accelerating the reaction.

[0016] In the cracking reaction, the organic molecules in the resin waste are adsorbed onto the active sites on the surface of the metal oxide. When the small organic molecules generated during the resin cracking process approach the metal oxide surface, they will first be adsorbed by the active sites. During the adsorption process, the metal ions on the surface of the metal oxide will interact with the electronegative atoms in the organic molecules, causing the organic molecules to rearrange on the metal surface; when the organic molecules are adsorbed on the active sites, the chemical bonds in the molecules will be polarized due to the interaction with the surface metal oxide. Specifically, the metal ions on the oxide surface can interact with the covalent bonds or polar bonds in the organic matter, weakening the strength of these chemical bonds, thereby reducing the energy barrier for their breakage; after the organic molecules are activated and cracked, the generated products will desorb from the metal oxide surface and be released into the gas phase or liquid phase. This process releases the surface active sites. The desorption of the products also avoids the saturation of the surface active sites, ensuring the continuation of the catalytic process.

[0017] A large amount of heat is released during the resin cracking process, part of which can be used to drive the reduction reaction of metal oxides in copper-containing sludge. In turn, the reduction reaction of copper oxides is endothermic, which effectively balances the energy demand of the entire system, reduces additional energy input, and enables the entire process to be carried out efficiently at a relatively low temperature; resin waste interacts with the surface active sites of metal oxides in copper-containing sludge to promote the reaction together. The reducing gas released by resin cracking reacts with metal oxides, causing the metal oxides to undergo a redox process. The reduction process of metal ions produces new active sites, which further catalyze the resin cracking reaction.

[0018] As a preferred technical solution of the present invention, in step S1, the feeding amount of the copper-containing sludge is 30-50kg, for example, it can be 30kg, 32kg, 34kg, 36kg, 38kg, 40kg, 42kg, 44kg, 46kg, 48kg or 50kg, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0019] In some optional instances, the first temperature is 100-120°C, for example, it can be 100°C, 102°C, 104°C, 106°C, 108°C, 110°C, 112°C, 114°C, 116°C, 118°C or 120°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0020] In some optional examples, the drying time is 4-6h, for example, it can be 4.0h, 4.2h, 4.4h, 4.6h, 4.8h, 5.0h, 5.2h, 5.4h, 5.6h, 5.8h or 6.0h, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0021] In some optional instances, the target moisture content is 15-20%, for example, it can be 15%, 15.5%, 16.0%, 16.5%, 17.0%, 17.5%, 18.0%, 18.5%, 19.0%, 19.5% or 20.0%, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0022] In some optional examples, the aperture of the sieve is 2-5 mm, for example, it can be 2.0 mm, 2.3 mm, 2.6 mm, 2.9 mm, 3.2 mm, 3.5 mm, 3.8 mm, 4.1 mm, 4.4 mm, 4.7 mm or 5.0 mm, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0023] In some optional instances, the second temperature is 300-310°C, for example, it can be 300°C, 301°C, 302°C, 303°C, 304°C, 305°C, 306°C, 307°C, 308°C, 309°C or 310°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0024] In some optional examples, the pre-oxidation treatment time is 1-2h, for example, it can be 1.0h, 1.1h, 1.2h, 1.3h, 1.4h, 1.5h, 1.6h, 1.7h, 1.8h, 1.9h or 2.0h, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0025] As a preferred technical solution of the present invention, in step S2, the feeding amount of the resin waste is 10-20kg, for example, it can be 10kg, 11kg, 12kg, 13kg, 14kg, 15kg, 16kg, 17kg, 18kg, 19kg or 20kg, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0026] In some optional instances, the target particle size is 3-5 mm, for example, 3.0 mm, 3.2 mm, 3.4 mm, 3.6 mm, 3.8 mm, 4.0 mm, 4.2 mm, 4.4 mm, 4.6 mm, 4.8 mm or 5.0 mm, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0027] In some optional instances, the third temperature is 260-280°C, for example, it can be 260°C, 262°C, 264°C, 266°C, 268°C, 270°C, 272°C, 274°C, 276°C, 278°C or 280°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0028] In some optional examples, the pre-degassing time is 1-2h, for example, it can be 1.0h, 1.1h, 1.2h, 1.3h, 1.4h, 1.5h, 1.6h, 1.7h, 1.8h, 1.9h or 2.0h, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0029] In some optional examples, the mass fraction of the acetic acid solution is 5-10wt.%, for example, it can be 5.0wt.%, 5.5wt.%, 6.0wt.%, 6.5wt.%, 7.0wt.%, 7.5wt.%, 8.0wt.%, 8.5wt.%, 9.0wt.%, 9.5wt.% or 10.0wt.%, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0030] In some optional examples, the volume of the acetic acid solution is 1-1.5 L, for example, it can be 1.0 L, 1.05 L, 1.10 L, 1.15 L, 1.20 L, 1.25 L, 1.30 L, 1.35 L, 1.40 L, 1.45 L or 1.50 L, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0031] In some optional examples, the swelling treatment time is 12-14h, for example, it can be 12.0h, 12.2h, 12.4h, 12.6h, 12.8h, 13.0h, 13.2h, 13.4h, 13.6h, 13.8h or 14.0h, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0032] As a preferred technical solution of the present invention, in step S3, the feeding amount of the pretreated copper-containing sludge is 20-30kg, for example, it can be 20kg, 21kg, 22kg, 23kg, 24kg, 25kg, 26kg, 27kg, 28kg, 29kg or 30kg, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0033] In some optional examples, the feeding amount of the pretreated resin waste is 20-30kg, for example, it can be 20kg, 21kg, 22kg, 23kg, 24kg, 25kg, 26kg, 27kg, 28kg, 29kg or 30kg, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0034] In some optional instances, the fourth temperature is 350-400°C, for example, it can be 350°C, 355°C, 360°C, 365°C, 370°C, 375°C, 380°C, 385°C, 390°C, 395°C or 400°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0035] In some optional examples, the heating rate of the fourth temperature is 10° C. / min.

[0036] In some optional examples, the cleavage reaction time is 1-2h, for example, it can be 1.0h, 1.1h, 1.2h, 1.3h, 1.4h, 1.5h, 1.6h, 1.7h, 1.8h, 1.9h or 2.0h, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0037] Compared with the prior art, the present invention has the following beneficial effects:

[0038] (1) The present invention proposes to carry out low-temperature pyrolysis treatment of copper-containing sludge and resin waste in a coordinated manner, and the metal oxides in the sludge are used as catalysts to promote the pyrolysis reaction of the resin waste, while achieving the reduction of copper in the sludge. The reducing gas generated during the resin pyrolysis process can further promote the metal reduction reaction, forming a synergistic effect and improving the overall efficiency of the pyrolysis reaction. Not only can the two wastes be treated at the same time, but also a higher resource utilization rate can be achieved through the interaction between the wastes;

[0039] (2) The present invention pre-oxidizes the copper-containing sludge and heats it in an air atmosphere to remove volatile organic matter and moisture in the sludge, thereby increasing the exposure of the metal oxides and forming more active sites on their surface, thereby improving the catalytic activity of the metal oxides in the cracking reaction. At the same time, the resin waste is crushed, pre-degassed and swollen to make its internal structure looser, which is beneficial to the conduction of heat and the diffusion of reactants during the cracking process, thereby significantly improving the cracking efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 A flow chart of a method for treating copper-containing sludge in cooperation with resin waste at low temperature cracking provided in Examples 1-8 of the present invention;

[0041] Figure 2 This is a SEM image of the resin waste obtained in Example 1 of the present invention after swelling treatment by immersion in acetic acid solution. DETAILED DESCRIPTION

[0042] The technical solution of the present invention is described in detail below in conjunction with specific embodiments and their accompanying drawings. The embodiments recorded herein are specific embodiments of the present invention, which are used to illustrate the concept of the present invention; these descriptions are explanatory and exemplary and should not be construed as limitations on the embodiments of the present invention and the scope of protection of the present invention. In addition to the embodiments recorded herein, those skilled in the art can also adopt other obvious technical solutions based on the contents disclosed in the claims of this application and its specification, including technical solutions that adopt any obvious replacements and modifications to the embodiments recorded herein.

[0043] The chemical reagents used in the examples and comparative examples of the present invention are all commercially available products, and their brands, specifications and manufacturer information are as follows:

[0044] Acetic acid, mass fraction 36wt.%, Shandong Xinhe New Materials Co., Ltd.;

[0045] Other raw materials can be purchased from the market.

[0046] Example 1

[0047] This embodiment provides a method for treating copper-containing sludge by cooperating with resin waste at low temperature cracking, such as Figure 1 As shown, the method specifically comprises the following steps:

[0048] Step S1, placing 32 kg of copper-containing sludge in a hot air dryer, fully drying at 105° C. for 4.3 hours, and after the moisture content is reduced to below 17%, sieving the dried sludge using a sieve with a pore size of 2 mm, and then heating to 305° C. for pre-oxidation treatment for 1.3 hours to obtain pre-treated copper-containing sludge;

[0049] Step S2, crushing 12 kg of resin waste into a particle size of 3.5 mm, then raising the temperature to 265° C. for pre-degassing treatment for 1.1 h, immersing in 1.1 L, 6.5 wt.% acetic acid solution for swelling treatment for 12.6 h, and filtering to obtain pre-treated resin waste;

[0050] Step S3, 25 kg of pretreated copper-containing sludge and 22 kg of pretreated resin waste are mixed evenly and placed at 360° C. for a cracking reaction for 1.3 h, a nitrogen atmosphere is maintained, and a gas collection device and a condensation system are connected to collect cracking products.

[0051] Figure 2 (a) and (b) are both resin wastes after swelling treatment by immersion in acetic acid solution. It can be seen that the cross-linked structure of the resin is destroyed after swelling treatment.

[0052] Example 2

[0053] This embodiment provides a method for treating copper-containing sludge by cooperating with resin waste at low temperature cracking, such as Figure 1 As shown, the method specifically comprises the following steps:

[0054] Step S1, placing 36 kg of copper-containing sludge in a hot air dryer, fully drying at 108° C. for 4.7 hours, and after the moisture content is reduced to below 16%, sieving the dried sludge using a sieve with a pore size of 3 mm, and then heating it to 303° C. for pre-oxidation treatment for 1.5 hours to obtain pre-treated copper-containing sludge;

[0055] Step S2, crushing 14 kg of resin waste into a particle size of 4.5 mm, then raising the temperature to 269° C. for pre-degassing treatment for 1.4 h, immersing in 1.2 L, 6.0 wt.% acetic acid solution for swelling treatment for 12.3 h, and filtering to obtain pre-treated resin waste;

[0056] Step S3, 22 kg of pretreated copper-containing sludge and 24 kg of pretreated resin waste are mixed evenly and placed at 370° C. for a cracking reaction for 1.5 h, a nitrogen atmosphere is maintained, and a gas collection device and a condensation system are connected to collect cracking products.

[0057] Example 3

[0058] This embodiment provides a method for treating copper-containing sludge by cooperating with resin waste at low temperature cracking, such as Figure 1 As shown, the method specifically comprises the following steps:

[0059] Step S1, placing 40 kg of copper-containing sludge in a hot air dryer, fully drying at 113° C. for 4.9 hours, and after the moisture content is reduced to below 15%, sieving the dried sludge using a sieve with a pore size of 4 mm, and then heating to 300° C. for pre-oxidation treatment for 1.7 hours to obtain pre-treated copper-containing sludge;

[0060] Step S2, crushing 11 kg of resin waste into a particle size of 4.0 mm, then raising the temperature to 272° C. for pre-degassing treatment for 1.2 hours, immersing in 1.3 L, 5.0 wt.% acetic acid solution for swelling treatment for 12.8 hours, and filtering to obtain pre-treated resin waste;

[0061] Step S3, 23 kg of pretreated copper-containing sludge and 21 kg of pretreated resin waste are mixed evenly and placed at 375° C. for a cracking reaction for 1.6 h, while maintaining a nitrogen atmosphere, and connecting a gas collection device and a condensation system to collect cracking products.

[0062] Example 4

[0063] This embodiment provides a method for treating copper-containing sludge by cooperating with resin waste at low temperature cracking, such as Figure 1 As shown, the method specifically comprises the following steps:

[0064] Step S1, placing 42 kg of copper-containing sludge in a hot air dryer, fully drying at 115° C. for 5.2 hours, and after the moisture content is reduced to below 18%, sieving the dried sludge using a sieve with a pore size of 3 mm, and then heating to 306° C. for pre-oxidation treatment for 1.7 hours to obtain pre-treated copper-containing sludge;

[0065] Step S2, crushing 16 kg of resin waste into a particle size of 3.0 mm, then raising the temperature to 275° C. for pre-degassing treatment for 1.5 h, immersing in 1.5 L, 7.0 wt.% acetic acid solution for swelling treatment for 13.3 h, and filtering to obtain pre-treated resin waste;

[0066] Step S3, 26 kg of pretreated copper-containing sludge and 25 kg of pretreated resin waste are mixed evenly and placed at 380° C. for a cracking reaction for 1.4 h, a nitrogen atmosphere is maintained, and a gas collection device and a condensation system are connected to collect cracking products.

[0067] Example 5

[0068] This embodiment provides a method for treating copper-containing sludge by cooperating with resin waste at low temperature cracking, such as Figure 1 As shown, the method specifically comprises the following steps:

[0069] Step S1, placing 45 kg of copper-containing sludge in a hot air dryer, fully drying at 107° C. for 5.5 hours, and after the moisture content is reduced to below 19%, sieving the dried sludge using a sieve with a pore size of 4 mm, and then heating it to 302° C. for pre-oxidation treatment for 1.8 hours to obtain pre-treated copper-containing sludge;

[0070] Step S2, crushing 14 kg of resin waste into a particle size of 4.5 mm, then raising the temperature to 273° C. for pre-degassing treatment for 1.7 hours, immersing in 1.2 L, 8.0 wt.% acetic acid solution for swelling treatment for 12.5 hours, and filtering to obtain pre-treated resin waste;

[0071] Step S3, 21 kg of pretreated copper-containing sludge and 23 kg of pretreated resin waste are mixed evenly and placed at 370° C. for a cracking reaction for 1.2 h, a nitrogen atmosphere is maintained, and a gas collection device and a condensation system are connected to collect cracking products.

[0072] Example 6

[0073] This embodiment provides a method for treating copper-containing sludge by cooperating with resin waste at low temperature cracking, such as Figure 1 As shown, the method specifically comprises the following steps:

[0074] Step S1, placing 36 kg of copper-containing sludge in a hot air dryer, fully drying at 111° C. for 5.1 hours, and after the moisture content is reduced to below 18%, sieving the dried sludge using a sieve with a pore size of 5 mm, and then heating it to 306° C. for pre-oxidation treatment for 1.5 hours to obtain pre-treated copper-containing sludge;

[0075] Step S2, crushing 13 kg of resin waste into a particle size of 3.5 mm, then raising the temperature to 270° C. for pre-degassing treatment for 1.3 h, immersing in 1.4 L, 9.0 wt.% acetic acid solution for swelling treatment for 13.1 h, and filtering to obtain pre-treated resin waste;

[0076] Step S3, 26 kg of pretreated copper-containing sludge and 27 kg of pretreated resin waste are mixed evenly and placed at 390° C. for a cracking reaction for 1.3 h, a nitrogen atmosphere is maintained, and a gas collection device and a condensation system are connected to collect cracking products.

[0077] Example 7

[0078] This embodiment provides a method for treating copper-containing sludge by cooperating with resin waste at low temperature cracking, such as Figure 1 As shown, the method specifically comprises the following steps:

[0079] Step S1, placing 41 kg of copper-containing sludge in a hot air dryer, fully drying at 110° C. for 5.4 hours, and after the moisture content is reduced to below 17%, sieving the dried sludge using a sieve with a pore size of 3 mm, and then heating it to 301° C. for pre-oxidation treatment for 1.7 hours to obtain pre-treated copper-containing sludge;

[0080] Step S2, crushing 18 kg of resin waste into a particle size of 4.0 mm, then raising the temperature to 274° C. for pre-degassing treatment for 1.6 hours, immersing in 1.2 L, 8.5 wt.% acetic acid solution for swelling treatment for 13.5 hours, and filtering to obtain pre-treated resin waste;

[0081] Step S3, 22 kg of pretreated copper-containing sludge and 24 kg of pretreated resin waste are mixed evenly and placed at 370° C. for a cracking reaction for 1.7 h, while maintaining a nitrogen atmosphere, and connecting a gas collection device and a condensation system to collect cracking products.

[0082] Example 8

[0083] This embodiment provides a method for treating copper-containing sludge by cooperating with resin waste at low temperature cracking, such as Figure 1 As shown, the method specifically comprises the following steps:

[0084] Step S1, placing 38 kg of copper-containing sludge in a hot air dryer, fully drying at 114° C. for 5.7 hours, and after the moisture content is reduced to below 16%, sieving the dried sludge using a sieve with a pore size of 4 mm, and then heating it to 306° C. for pre-oxidation treatment for 1.4 hours to obtain pre-treated copper-containing sludge;

[0085] Step S2, crushing 14 kg of resin waste into a particle size of 4.5 mm, then raising the temperature to 270° C. for pre-degassing treatment for 1.5 h, immersing in 1.3 L, 7.5 wt.% acetic acid solution for swelling treatment for 12.7 h, and filtering to obtain pre-treated resin waste;

[0086] Step S3, 27 kg of pretreated copper-containing sludge and 28 kg of pretreated resin waste are mixed evenly and placed at 375° C. for a cracking reaction for 1.4 h, a nitrogen atmosphere is maintained, and a gas collection device and a condensation system are connected to collect cracking products.

[0087] Comparative Example 1

[0088] This embodiment provides a method for low-temperature pyrolysis treatment of copper-containing sludge in conjunction with resin waste. The difference from Example 1 is that in step S1, the pre-oxidation treatment temperature is adjusted to 325°C. Compared with Example 1, the pre-oxidation treatment temperature is increased by 20°C. Other process parameters and operating conditions are exactly the same as those in Example 1.

[0089] Comparative Example 2

[0090] This embodiment provides a method for low-temperature cracking treatment of copper-containing sludge in conjunction with resin waste. The difference from Example 1 is that in step S1, the pre-oxidation treatment temperature is adjusted to 285°C. Compared with Example 1, the pre-oxidation treatment temperature is reduced by 20°C. The other process parameters and operating conditions are exactly the same as those in Example 1.

[0091] Comparative Example 3

[0092] This embodiment provides a method for treating copper-containing sludge in conjunction with resin waste at low temperature cracking. The difference from Embodiment 1 is that in step S2, the mass fraction of the acetic acid solution is adjusted to 11.5 wt.%, and the mass fraction of the acetic acid solution is increased by 5 wt.% relative to Embodiment 1. The other process parameters and operating conditions are exactly the same as those in Embodiment 1.

[0093] Comparative Example 4

[0094] This embodiment provides a method for treating copper-containing sludge in conjunction with resin waste at low temperature cracking. The difference from Embodiment 1 is that in step S2, the mass fraction of the acetic acid solution is adjusted to 1.5 wt.%, which is reduced by 5 wt.% compared with Embodiment 1. Other process parameters and operating conditions are exactly the same as those in Embodiment 1.

[0095] The gas products of low-temperature pyrolysis of copper-containing sludge and resin waste are mainly H2, CH4, CO2 and CO. Only the four gases are counted here, and the pyrolysis gas is detected and analyzed using a gas chromatograph (GC-9790plus, Fuli).

[0096] Table 1: Table of products of low temperature pyrolysis of copper-containing sludge and resin waste in Examples 1-8 and Comparative Examples 1-4

[0097]

[0098]

[0099] It can be seen from the data of Example 1, Comparative Example 1 and Comparative Example 2 that the mass fraction of cracked coke in Comparative Example 1 is lower than that in Example 1, and the proportion of H2 and CH4 in Comparative Example 1 in the cracked gas is lower than that in Example 1, and the proportion of CO2 and CO is higher than that in Example 1; the mass fraction of cracked coke in Comparative Example 2 is higher than that in Example 1, and the proportion of H2 and CH4 in Comparative Example 2 in the cracked gas is lower than that in Example 1, and the proportion of CO2 and CO is higher than that in Example 1. In Comparative Example 1, the pre-oxidation treatment temperature of the copper-containing sludge is too high, resulting in excessive oxidation of organic matter and metal organic matter in the copper-containing sludge, generating more oxidizing gas, and reducing the ratio of combustible gas H2 and CH4; in Comparative Example 2, the pre-oxidation treatment temperature of the copper-containing sludge is too low, the metal oxide cannot be fully exposed, the catalytic effect of copper oxide is insufficient, the mass fraction of coke increases, the cracking is not sufficient, and the ratio of combustible gas H2 and CH4 decreases.

[0100] It can be seen from the data of Example 1, Comparative Example 3 and Comparative Example 4 that the mass fraction of cracked coke in Comparative Example 3 is lower than that in Example 1. In the cracked gas, the proportion of H2 and CH4 in Comparative Example 3 is lower than that in Example 1, and the proportion of CO2 and CO is higher than that in Example 1; the mass fraction of cracked coke in Comparative Example 4 is higher than that in Example 1. In the cracked gas, the proportion of H2 and CH4 in Comparative Example 4 is lower than that in Example 1, and the proportion of CO2 and CO is higher than that in Example 1. In Comparative Example 3, high concentration of acetic acid may cause excessive dissolution of resin waste, and the mass fraction of coke is reduced, but the mass fraction of acetic acid solution is too high, which may lead to more oxidizing gas generation, and the overall cracking gas ratio increases, but the ratio of combustible gas H2 and CH4 decreases; in Comparative Example 4, the mass fraction of acetic acid solution is too low, and the cross-linked structure of the resin is not fully destroyed, resulting in insufficient subsequent cracking, more oxidizing gas generation, a decrease in the ratio of H2 and CH4, and an increase in the mass fraction of coke.

[0101] The applicant declares that the above is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention shall fall within the protection scope and disclosure scope of the present invention.

Claims

1. A method for treating copper-containing sludge by low-temperature pyrolysis of resin waste, characterized in that: The method is: Step S1, placing the copper-containing sludge in a hot air dryer, fully drying it at a first temperature, screening the dried sludge with a screen after the moisture content drops below a target moisture content, and then heating it to a second temperature for pre-oxidation treatment to obtain pre-treated copper-containing sludge; Step S2, crushing the resin waste to a target particle size, then raising the temperature to a third temperature for pre-degassing treatment, immersing in an acetic acid solution for swelling treatment after the pre-degassing treatment, and filtering to obtain pre-treated resin waste; Step S3, mixing the pretreated copper-containing sludge and the pretreated resin waste evenly and placing them at a fourth temperature for cracking reaction, maintaining a nitrogen atmosphere, and connecting a gas collection device and a condensation system to collect cracking products.

2. The method for treating copper-containing sludge by low-temperature pyrolysis of resin waste according to claim 1, characterized in that: In step S1: The feeding amount of the copper-containing sludge is 30-50kg; The first temperature is 100-120°C.

3. The method for treating copper-containing sludge by low-temperature pyrolysis of resin waste according to claim 1, characterized in that: In step S1: The drying time is 4-6h; The target moisture content is 15-20%.

4. The method for treating copper-containing sludge by low-temperature pyrolysis of resin waste according to claim 1, characterized in that: In step S1: The pore size of the sieve is 2-5 mm; The second temperature is 300-310°C; The pre-oxidation treatment time is 1-2h.

5. The method for treating copper-containing sludge by low-temperature pyrolysis of resin waste according to claim 1, characterized in that: In step S2: The resin waste is epoxy resin, and the feeding amount is 10-20kg; The target particle size is 3-5 mm.

6. The method for treating copper-containing sludge by low-temperature pyrolysis of resin waste according to claim 1, characterized in that: In step S2: The third temperature is 260-280°C; The pre-degassing treatment time is 1-2h.

7. The method for treating copper-containing sludge by low-temperature pyrolysis of resin waste according to claim 1, characterized in that: In step S2: The mass fraction of the acetic acid solution is 5-10wt.%, and the volume is 1-1.5L; The swelling treatment time is 12-14 hours.

8. The method for treating copper-containing sludge by low-temperature pyrolysis of resin waste according to claim 1, characterized in that: In step S3: The feeding amount of the pre-treated copper-containing sludge is 20-30 kg; The feeding amount of the pre-treated resin waste is 20-30kg.

9. The method for treating copper-containing sludge by low-temperature pyrolysis of resin waste according to claim 1, characterized in that: In step S3: The fourth temperature is 350-400° C.; The heating rate of the fourth temperature is 10°C / min.

10. The method for treating copper-containing sludge by cooperating with resin waste at low temperature cracking according to claim 1, characterized in that: In step S3, the cleavage reaction time is 1-2h.

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