Method for comprehensively recovering waste nickel net by carbonylation method

Abstract

The invention discloses a method for comprehensively recycling a waste nickel net through a carbonylation method. According to the method, after the waste nickel net is subjected to mechanical crushing, screening, cleaning and drying pretreatment, a carbonyl compound removal tower of a vertical structure is filled with the waste nickel net, multiple material layers are arranged in the tower, and all the material layers are filled with pretreated waste nickel net particles. The carbonylation synthesis production exhaust gas is introduced into the tower, under the conditions that the temperature is 300-450 DEG C and the pressure is 0.1-0.2 MPa, waste nickel net particles are used as a reaction matrix, pyrolytic deposition of carbonyl compounds in the exhaust gas is achieved, and meanwhile nickel resources are recycled. And purifying the gas subjected to pyrolysis deposition to obtain high-purity CO, recycling the high-purity CO in the carbonylation synthesis process, participating the nickel-deposited material in the carbonylation synthesis reaction, and carrying out rectification decomposition to obtain a high-purity carbonyl product. According to the method, collaborative recycling of the waste nickel net and the carbonylation synthesis exhaust gas is achieved, the resource utilization rate is high, and the method is environmentally friendly, economical and remarkable in industrial application value.

Description

Technical Field

[0001] This invention belongs to the interdisciplinary field of waste nickel resource recycling and carbonyl metallurgy, specifically involving a method for the comprehensive recycling of waste nickel wire mesh using carbonylation, applicable to resource recycling and green production scenarios in multiple fields such as nickel metallurgy, chemical catalysis, and environmental governance. Background Technology

[0002] Waste nickel mesh is a typical solid waste generated by industries such as nickel catalytic reactions, chemical equipment filtration, and metallurgical purification. Its nickel metal content is usually no less than 80%, and in some high-end applications, the nickel content of waste nickel mesh even exceeds 95%, making it extremely valuable for recycling. However, existing waste nickel mesh recycling technologies have many insurmountable drawbacks, failing to achieve a synergistic balance between efficient resource recovery and environmental governance.

[0003] Current mainstream recycling technologies are mainly divided into two categories: pyrometallurgical and hydrometallurgical processes. Pyrometallurgical recycling processes extract nickel metal through high-temperature roasting and smelting. Although this can achieve preliminary nickel recovery, it suffers from extremely high energy consumption. Processing each ton of scrap nickel mesh requires more than 500 kg of standard coal, and SO2 and NO are easily generated during the high-temperature process. x The presence of acidic gases and heavy metal fumes causes serious air pollution, requiring high costs for subsequent environmental remediation. The wet recycling process relies on strong acids such as sulfuric acid and hydrochloric acid to leach nickel ions, which is not only highly corrosive to production equipment and increases equipment maintenance costs, but also generates a large amount of nickel-containing wastewater. If not properly treated, it can easily lead to nickel pollution of soil and water bodies, posing serious ecological risks.

[0004] Meanwhile, the carbonyl metallurgical industry (such as the production of carbonyl nickel and carbonyl iron) generates a large amount of CO-rich exhaust gas (including carbonyl synthesis depressurization gas and distillation tail gas) during synthesis, distillation, and decomposition processes. The CO volume fraction in this exhaust gas is generally between 80% and 90%, possessing extremely high recycling and reuse value. However, currently, the industry primarily handles this exhaust gas through direct incineration. This leads to a significant waste of CO resources and losses in raw material costs. Furthermore, the incineration process generates a large amount of CO2, which is seriously contrary to the national "dual-carbon" strategic goal.

[0005] More importantly, in the existing technological system, the recycling of scrap nickel mesh and the treatment of exhaust gases from carbonylation synthesis are independent and fragmented systems: scrap nickel mesh recycling focuses only on the single extraction of nickel metal, without considering the synergistic utilization with industrial waste gas; exhaust gas treatment from carbonylation synthesis only focuses on the harmless disposal of gases, without combining it with the resource recovery of solid waste resources. This fragmented approach leads to low resource utilization and compounded environmental pressures. The industry urgently needs a synergistic process that can simultaneously achieve efficient recycling of scrap nickel mesh and resource utilization of exhaust gases from carbonylation synthesis, in order to break the dual dilemma of resource waste and environmental pollution. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the prior art and provide a method for the comprehensive recycling of waste nickel wire mesh via carbonylation. By synergistically treating the waste nickel wire mesh and the exhaust gas from carbonylation synthesis, the goal of recycling nickel resources, stabilizing the CO purification process, and recycling CO can be achieved.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: The present invention relates to a device for the comprehensive recycling of waste nickel mesh by carbonylation, comprising a vertical carbonyl removal tower. The tower body is provided with at least three material layers arranged from top to bottom. Each material layer is used to fill pre-treated waste nickel mesh particles. Adjacent material layers are separated by inclined baffles, which can ensure uniform gas flow and avoid local flow deviation. The top of the tower is provided with an exhaust gas inlet for introducing external exhaust gas into the tower to react with the waste nickel mesh particles; the bottom of the tower is provided with an exhaust gas outlet for discharging the reacted gas to the subsequent purification process. Heating devices are installed on the outer side of each material layer in the tower body to precisely control the reaction temperature of each material layer. The tower body is also equipped with pressure detection ports, temperature detection ports, waste nickel mesh particle filling ports, and waste nickel mesh particle discharging ports. At least one temperature detection port is set for each material layer to monitor the temperature of each material layer in real time and ensure reaction stability. The filling ports and discharging ports are set independently for each material layer, which can realize the individual filling, unloading and maintenance of each material layer, improving the operational flexibility of the equipment.

[0008] The waste nickel mesh particles filling each material layer have a particle size of 0.5 to 10 mm, and the filling height of a single material layer accounts for 1 / 3 of the effective height of the tower. This setting can ensure sufficient contact between the gas and the particles and improve the pyrolysis deposition efficiency.

[0009] The heating device is an electric heating jacket with a temperature control range of 300-450℃, which can accurately match the temperature requirements of the pyrolysis deposition reaction, and the temperature control is stable and the energy consumption is controllable.

[0010] The tower is a fixed-bed reactor with an inner diameter of 1000 mm and a height of 4000–5500 mm. The total height of the waste nickel mesh particles filling each material layer is 3000–4500 mm. This size design can adapt to the processing needs of large-scale nickel carbonylation production lines and ensure processing efficiency.

[0011] The present invention provides a method for the comprehensive recycling of waste nickel mesh via carbonylation, based on the aforementioned apparatus, comprising the following steps: Step (1): Preprocessing The waste nickel mesh raw material undergoes mechanical crushing, grading and screening, cleaning, and drying in sequence: A jaw crusher or hammer crusher is used to crush the waste nickel mesh to a particle size of 0.5–10 mm, ensuring sufficient specific surface area to improve subsequent reaction efficiency. Then, it is graded and screened through at least three layers of vibrating screens with mesh sizes of 0.5 mm, 5 mm, and 10 mm to remove large particles and fine powder that do not match the particle size, ensuring particle uniformity. Next, deionized water or a weakly acidic cleaning solution is used to clean the surface of the particles to remove oil, dust, and other impurities for 15–25 minutes. After cleaning, the particles are rinsed with deionized water until neutral. Finally, hot air drying is used to remove surface moisture, resulting in clean waste nickel mesh particles.

[0012] Step (2): Packing the carbonyl removal tower The clean waste nickel mesh particles obtained in step (1) are filled into each material layer of the carbonyl removal tower through the filling port on the tower body. The filling process adopts a layered compaction process to ensure that the airflow path between particles is uniform and to avoid local flow deviation. After filling, the sealing performance of the tower body and the effectiveness of each detection component are checked.

[0013] Step (3): Carbonyl pyrolysis deposition and CO recycling The exhaust gas from carbonylation synthesis (containing CO volume fraction ≥80%) is introduced into the carbonyl removal tower through the inlet at the top of the tower. The heating device is started to regulate the temperature of each material layer to 300-450℃, and the pressure inside the tower is monitored through the pressure detection port and maintained at 0.1-0.2MPa. As the exhaust gas flows through the waste nickel mesh granule material layer, the carbonyl compounds in it undergo a pyrolysis deposition reaction on the particle surface, realizing the removal of carbonyl compounds and the enrichment of nickel resources on the particle surface. The gas after pyrolysis deposition is discharged from the bottom outlet of the tower and sent to the downstream gas purification process for treatment to obtain high-purity CO with a purity of ≥96%. The high-purity CO is then temporarily stored in a CO gas holder and reused in the carbonylation synthesis process, with a CO recycling rate of >80%.

[0014] Step (4): Carbonylation synthesis and distillation decomposition High-purity CO temporarily stored in the CO gas holder is introduced into the carbonylation synthesis process and reacts with the nickel source (including the nickel metal in the waste nickel mesh particles and the nickel metal deposited by pyrolysis in step (3)) to generate carbonyl compounds; then the generated carbonyl compounds are sent to a distillation column and purified by continuous distillation process to obtain liquid carbonyl compounds with a purity ≥99.5%; the liquid carbonyl compounds are transferred to a decomposition system for decomposition to finally obtain high-purity carbonyl nickel products; The exhaust gas generated during the carbonylation synthesis and distillation decomposition process in this step is returned to the carbonyl removal tower in step (3) for recycling, so as to realize the closed-loop utilization of the gas throughout the entire process.

[0015] The present invention has the following advantages over the prior art: 1. Achieve synergistic resource utilization of solid waste and exhaust gas: By combining the recycling of waste nickel mesh with the treatment of exhaust gas from carbonylation synthesis, it not only achieves efficient recovery of nickel resources from waste nickel mesh with a direct nickel metal recovery rate of ≥94%, solving the problems of high energy consumption and high pollution in traditional pyrometallurgical and hydrometallurgical processes, but also achieves purification and reuse of CO in exhaust gas, avoiding the waste of resources from direct CO incineration, and increasing the comprehensive CO utilization rate of the production line by ≥10%.

[0016] 2. Strong process stability and adaptability: The vertical layered carbonyl removal tower and precise temperature and pressure control design ensure the stable progress of the carbonyl pyrolysis deposition reaction, reduce the processing load of the downstream CO purification process, and improve the stability of the purification process. At the same time, the process parameters can be flexibly adjusted according to the composition of the gas source and the properties of the waste nickel mesh, and can be seamlessly connected with large-scale nickel carbonyl production lines without the need for disruptive modifications to existing production lines, which greatly reduces the technical threshold and modification costs for industrial promotion.

[0017] 3. Significant dual advantages in environmental protection and economy: The entire process produces no SO2 or NO. x The generation of acidic gases, nickel-containing wastewater, and heavy metal fumes is eliminated without secondary pollution, aligning with the national "dual carbon" strategy. Through resource recycling, the consumption of fresh CO raw materials and the cost of processing waste nickel mesh are significantly reduced, improving the company's economic benefits and achieving coordinated development of environmental protection and the economy. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the carbonyl removal tower of the present invention; Figure 2 This is a process flow diagram of the carbonylation method for the comprehensive recovery of waste nickel mesh using the emission gas of this invention; Figure 1 In the diagram: a - exhaust gas inlet, b - exhaust gas outlet, c1, c2, c3 - scrap nickel mesh pellet feeding inlet, d1, d2, d3 - scrap nickel mesh pellet filling inlet, p - pressure detection port, t1, t2, t3 - temperature detection port. Detailed Implementation

[0019] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that the following embodiments are only used to illustrate the present invention and are not intended to limit the scope of protection of the present invention.

[0020] like Figure 1As shown, the device used in this invention is a carbonyl removal tower, which has a vertical structure with an exhaust gas inlet (a) at the top and an exhaust gas outlet (b) at the bottom. The tower body is divided into three layers from top to bottom: material layer one, material layer two, and material layer three. The material layers are separated by inclined partitions. Electric heating jackets (heating devices) are installed on the outside of each material layer. The tower body is equipped with pressure detection ports (p), temperature detection ports (t1, t2, t3), filling ports (d1, d2, d3), and discharge ports (c1, c2, c3).

[0021] Example 1: This embodiment uses the apparatus and method described in this invention to recycle waste nickel mesh. The specific steps are as follows: 1. Pretreatment: The waste nickel mesh raw material is crushed to a particle size of 0.5-10mm using a jaw crusher; it is then graded and screened through a three-layer vibrating screen (screen aperture of 0.5mm, 5mm, and 10mm), and particles with a particle size of 5-10mm are selected. The particles are then washed with dilute sulfuric acid (mass fraction of 5%) for 20 minutes, followed by rinsing with deionized water until neutral; and finally dried with hot air (temperature 120℃, time 30 minutes) to obtain clean waste nickel mesh particles.

[0022] 2. Carbonyl Removal Tower Packing: A vertical carbonyl removal tower with an inner diameter of 1000mm and a height of 4000mm is selected. Three material layers are set inside the tower, and each material layer is separated by inclined baffles. The clean nickel mesh particles mentioned above are filled into the three material layers through filling ports d1, d2, and d3. The filling height of each material layer is 1000mm, and the total filling height is 3000mm. During the filling process, the layers are compacted to ensure uniform airflow.

[0023] 3. Carbonyl Pyrolysis Deposition and CO Recycling: The exhaust gas from the carbonylation synthesis (80% CO by volume) is introduced, and the electric heating jacket on the outside of the tower is activated to adjust the temperature of each material layer to 300℃. The pressure inside the tower is monitored and maintained at 0.15 MPa through the pressure detection port. After the exhaust gas stays inside the tower for 8 hours, it is discharged from the bottom outlet b. The discharged gas is sent to a pressure swing adsorption purification unit to obtain CO with a purity of 96.2%. After temporary storage in a CO gas holder, it is recycled for the carbonylation synthesis process. The CO recycling rate is 82%.

[0024] 4. Carbonylation Synthesis and Distillation Decomposition: High-purity CO from the gas holder is introduced into the carbonylation synthesis reactor, where it reacts with waste nickel mesh particles enriched with nickel resources in the tower to generate carbonyl compounds. The carbonyl compounds are then continuously distilled to obtain high-purity carbonyl nickel products. The exhaust gas generated in this step is returned to the inlet a of the carbonyl removal tower for recycling. Testing showed that the final carbonyl nickel product obtained in this embodiment has a purity of 99.1% and a direct nickel metal recovery rate of 94.5%.

[0025] Example 2: This embodiment uses the apparatus and method described in this invention to recycle waste nickel mesh. The specific steps are as follows: 1. Pretreatment: The waste nickel mesh raw material is crushed to a particle size of 0.5-10mm using a hammer crusher; it is then graded and screened through a three-layer vibrating screen (screen apertures of 0.5mm, 5mm, and 10mm), and particles with a particle size of 0.5-5mm are selected. The particles are then washed with dilute hydrochloric acid (mass fraction 3%) for 20 minutes, followed by rinsing with deionized water until neutral; and finally dried with hot air (temperature 110℃, time 40 minutes) to obtain clean waste nickel mesh particles.

[0026] 2. Carbonyl Removal Tower Packing: A vertical carbonyl removal tower with an inner diameter of 1000mm and a height of 5500mm is selected. Three material layers are set inside the tower, and each material layer is separated by inclined baffles. The clean nickel mesh particles mentioned above are filled into the three material layers through filling ports d1, d2, and d3. The filling height of each material layer is 1500mm, and the total filling height is 4500mm. During the filling process, the layers are compacted to ensure uniform airflow.

[0027] 3. Carbonyl compound pyrolysis deposition and CO recycling: The exhaust gas from the carbonylation synthesis (80% CO by volume) is introduced, and the electric heating jacket on the outside of the tower is activated to adjust the temperature of each material layer to 450℃. The pressure inside the tower is monitored and maintained at 0.15MPa through the pressure detection port. After the exhaust gas stays in the tower for 16 hours, it is discharged from the bottom outlet b. The discharged gas is sent to a pressure swing adsorption purification unit to obtain CO with a purity of 98.4%. After temporary storage in a CO gas holder, it is recycled for the carbonylation synthesis process. The CO recycling rate is 88%.

[0028] 4. Carbonylation Synthesis and Distillation Decomposition: High-purity CO from the gas holder is introduced into the carbonylation synthesis reactor, where it reacts with waste nickel mesh particles enriched with nickel resources in the tower to generate carbonyl compounds. The carbonyl compounds are then continuously distilled to obtain high-purity carbonyl nickel products. The exhaust gas generated in this step is returned to the inlet a of the carbonyl removal tower for recycling. Testing showed that the final carbonyl nickel product obtained in this embodiment has a purity of 99.5% and a direct nickel metal recovery rate of 96.2%.

[0029] In summary, this invention innovatively constructs a synergistic treatment system for waste nickel mesh and exhaust gas from carbonylation synthesis. By controlling reaction conditions, it transforms waste nickel mesh into recyclable nickel resources, solving the problems of nickel waste and environmental issues associated with traditional disposal methods. Simultaneously, it efficiently captures trace carbonyl compounds in the exhaust gas from carbonylation synthesis, increasing the stability of the downstream CO gas purification process and achieving efficient CO purification and reuse, thus reducing the enterprise's CO production costs. The entire process operates stably and reliably, reducing solid waste and exhaust gas emissions, meeting low-carbon and environmental protection requirements, and significantly improving economic benefits through resource recycling. It demonstrates both economic and environmental value, providing a green and low-cost resource recycling solution for carbonylation metallurgy and related industries, and possesses broad prospects for industrial application.

Claims

1. A method for the comprehensive recycling of waste nickel wire mesh via carbonylation, characterized in that, Includes the following steps: (1) Pretreatment: Mechanical crushing, screening, washing and drying of waste nickel mesh raw materials; (2) Filling: The pretreated waste nickel mesh particles are filled into the carbonyl removal tower; (3) Pyrolysis deposition and CO recycling: The exhaust gas from carbonylation synthesis is introduced into the carbonyl removal tower and carbonyl pyrolysis deposition is carried out at 300-450℃ and 0.1-0.2MPa, so that the carbonyl in the exhaust gas is pyrolyzed and deposited on the surface of nickel mesh particles; the gas after pyrolysis deposition is purified to obtain CO, which is recycled for the carbonylation synthesis process. (4) Carbonylation synthesis: The recycled CO is carbonylated with the nickel source, and the resulting carbonyl product is distilled and decomposed to obtain high-purity carbonyl nickel product; the exhaust gas generated in the production process is returned to step (3) for recycling.

2. The method according to claim 1, characterized in that, The particle size of mechanical crushing in step (1) is controlled between 0.5 and 10 mm. Screening is carried out using a vibrating screen with 3 or more layers. Cleaning is done with deionized water or a low-concentration acid solution for 15 to 25 minutes. Drying is done with hot air.

3. The method according to claim 1, characterized in that, The carbonyl removal tower mentioned in step (2) is a vertical fixed-bed reactor with an inner diameter of 1000 mm and a height of 4000-5500 mm. The height of the nickel mesh particles filled in is 3000-4500 mm.

4. The method according to claim 1, characterized in that, In step (2), the carbonyl removal tower has at least three material layers from top to bottom. Each material layer is filled with pretreated nickel mesh particles, and the material layers are separated by inclined baffles. Each material layer is equipped with a heating device on its outer side, and the tower body is equipped with a pressure detection port, a temperature detection port for each material layer, a nickel mesh particle filling port, and a discharge port.

5. The method according to claim 4, characterized in that, The particle size range of the nickel mesh particles filling each material layer is 0.5 to 10 mm, and the filling height of each material layer accounts for 1 / 3 of the effective height of the tower body.

6. The method according to claim 1, characterized in that, The CO volume fraction in the exhaust gas from the carbonylation synthesis in step (3) is ≥80%; the CO purity after purification is ≥96%, and the utilization rate of the CO recycled to the carbonylation synthesis process is >80%.

7. The method according to claim 1, characterized in that, The nickel source mentioned in step (4) includes the nickel metal of the waste nickel mesh particles themselves and the nickel metal deposited by pyrolysis in step (3); the carbonyl distillation decomposition adopts a continuous distillation process, and the purity of the obtained carbonyl nickel product is ≥99%, and the direct recovery rate of nickel metal is ≥94%.

8. A carbonyl removal apparatus for implementing the method according to any one of claims 1 to 7, characterized in that, The invention includes a vertical carbonyl removal tower, wherein at least three material layers are arranged sequentially from top to bottom inside the tower, each material layer is used to fill pretreated waste nickel mesh particles, and adjacent material layers are separated by inclined partitions. The tower body is provided with an exhaust gas inlet at the top and an exhaust gas outlet at the bottom; Heating devices are installed on the outer side of each material layer of the tower body. The tower body is also equipped with pressure detection ports, temperature detection ports, waste nickel mesh particle filling ports, and waste nickel mesh particle feeding ports.

9. The apparatus according to claim 8, characterized in that, The particle size of the scrap nickel mesh particles filling each material layer is 0.5-10mm, and the filling height of a single material layer accounts for 1 / 3 of the effective height of the tower body; the heating device is an electric heating jacket, and the temperature control range of the electric heating jacket is 300-450℃; the tower body is a fixed bed reactor, the inner diameter of the tower is 1000mm, the height of the tower body is 4000-5500mm, and the total height of the scrap nickel mesh particles filling each material layer is 3000-4500mm.

10. The apparatus according to claim 8, characterized in that, At least one temperature detection port is set for each material layer to monitor the reaction temperature of each material layer in real time; the filling port and the discharge port are set independently for each material layer to realize the individual filling and unloading of each material layer.

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