Process and equipment for recycling waste ionic liquid

Abstract

The invention relates to a waste ionic liquid recycling process and equipment, the equipment comprises a hydrolysis tank, a three-stage oil separator, a buffer tank, a reaction tank and a filter press, monitoring instruments are arranged in the hydrolysis tank, the buffer tank and the reaction tank, and conveying equipment is arranged on the hydrolysis tank, the buffer tank and the reaction tank. According to the process and equipment for recycling the waste ionic liquid, through a hydrolysis treatment process, the waste ionic liquid is firstly subjected to controllable hydrolysis dilution in a hydrolysis tank, the adding sequence of firstly injecting industrial water and then slowly and automatically flowing and adding the waste ionic liquid is adopted, so that a violent reaction is avoided when the waste ionic liquid is mixed with water, and the operation safety is guaranteed; through the treatment process of oil separation, neutralization precipitation and filter pressing, oil-water separation is achieved through an oil separation tank, an upper-layer oil phase is recycled, a lower-layer water phase is transferred into a reaction tank through a buffer tank, alkali is added to adjust the pH to enable copper ions to form copper hydroxide precipitation, finally, a copper hydroxide product is obtained through filter pressing, filtrate is fed into a sewage treatment system, and resource utilization of harmful components is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of resource utilization of hazardous wastes, and specifically to a process and equipment for the resource utilization of waste ionic liquids. Background Art

[0002] Under the background of environmental protection and sustainable development, the quality of oil products in China has been further upgraded. The market share of C4 alkylated oil with high octane number, low emissions and high stability has increased significantly. Among them, a new industrial alkylation process and equipment using ionic liquid catalysts with high catalytic activity and high selectivity have been built and applied on a large scale. After the ionic liquid catalyst is deactivated, a large amount of acidic waste ionic liquid will be generated, and its main components are: AlCI3, CuCl, CuCl2, Et3NHCl, etc. Recycling copper from waste ionic liquid can not only improve economic benefits, achieve the resource utilization of waste and sustainable development, but also reduce the total amount of waste liquid and the cost of waste liquid disposal.

[0003] At present, the method for recycling copper is to recover copper from acidic waste liquid, mainly including chemical precipitation method, electrolysis method, ion exchange method, solvent extraction method, membrane separation technology, etc. The chloroaluminate ionic liquid waste catalyst contains acid-soluble oil, and there are still challenges such as high cost and complex process in recycling copper. Therefore, it is very necessary to develop a process and equipment for recycling copper from oil-containing waste ionic liquid, so a process and equipment for the resource utilization of waste ionic liquid are proposed. Summary of the Invention

[0004] Aiming at the deficiencies of the prior art, the present invention provides a process and equipment for the resource utilization of waste ionic liquid, which has the advantages of safe operation, high recovery rate, etc., realizes the recovery of copper in oil-containing waste ionic liquid, and effectively solves the problem of safety risks in the process of waste ionic liquid treatment.

[0005] To achieve the above object, the present invention provides the following technical solution: A waste ionic liquid resource utilization equipment, including a hydrolysis tank, a three-stage oil separator, a buffer tank, a reaction tank and a filter press. Monitoring instruments are arranged in the hydrolysis tank, the buffer tank and the reaction tank, and conveying equipment is arranged on the hydrolysis tank, the buffer tank and the reaction tank; The monitoring instruments include an online pH meter and a liquid level meter. The online pH meter is fixedly installed inside the reaction tank, the liquid level meter is fixedly installed inside the buffer tank. The conveying equipment includes a metering pump, a screw pump and two centrifugal pumps. The two centrifugal pumps are respectively connected to the outlet of the hydrolysis tank and the outlet of the buffer tank. The centrifugal pump in the hydrolysis tank is connected to the three-stage oil separator, the centrifugal pump in the buffer tank is connected to the inlet of the reaction tank, the screw pump is respectively connected to the outlet of the reaction tank and the inlet of the filter press, the metering pump is connected to the reaction tank. A skimmer is installed on the three-stage oil separator. Stirring devices are arranged on both the hydrolysis tank and the reaction tank. A diversion pipe connected to the buffer tank is installed at the bottom of the three-stage oil separator.

[0006] Further, the stirring device is a paddle stirrer, a cooling jacket is provided on the hydrolysis tank, the feed inlet of the hydrolysis tank is a self-flow type anti-splash structure, and the bottoms of the hydrolysis tank, the buffer tank and the reaction tank all adopt a conical structure and are provided with high-pressure backwashing interfaces.

[0007] Further, inclined plate fillers are arranged in each stage of the three-stage oil separator, the oil collection tank at the end of the three-stage oil separator is connected to the incineration system, and a suspended matter interception net is arranged at the water outlet of the three-stage oil separator.

[0008] Further, a process for the resource utilization of waste ion liquid includes the following steps: S1. Hydrolysis treatment: Inject industrial water into the hydrolysis tank, then place the waste ion liquid storage container above the feed inlet of the hydrolysis tank and connect it through a pipeline. Open the bottom valve of the waste ion liquid storage container to make the waste ion liquid flow into the hydrolysis tank. At the same time, start the stirring device to fully mix the industrial water and the waste ion liquid. After the reaction ends, stop the stirring. S2. Oil-water separation: Start the centrifugal pump to pump the hydrolyzate in the hydrolysis tank into the three-stage oil separator. Utilize the gravity separation principle of the oil separator at each stage to make the floating oil with a smaller density slowly float to the liquid surface. The lower water phase flows through the bottom guide pipe of the tank and flows into the buffer tank by self-flow. Regularly start the oil scraper to collect the floating oil on the upper layer and store it in a special container. S3. Neutralization reaction: The lower layer of the hydrolyzate is temporarily stored in the buffer tank, and the liquid level gauge in the buffer tank is used to monitor the height of the lower water phase. When the reaction tank meets the treatment conditions, start the centrifugal pump to pump the lower layer of the hydrolyzate in the buffer tank into the reaction tank until the lower layer of the hydrolyzate reaches 70%-80% of the volume of the reaction tank. Add liquid caustic soda to the reaction tank, and control the feeding rate and volume of the liquid caustic soda through a metering pump to carry out two-stage alkali treatment. At the same time, start the stirring device to make the caustic soda solution and the lower layer of the hydrolyzate mix evenly. Use the on-line pH meter on the reaction tank to monitor the pH value of the solution in real time, and the copper, aluminum and other ions in the solution fully form hydroxide precipitates. S4. Solid-liquid separation: After the neutralization reaction is completed, pump the slurry in the reaction tank into a filter press through a screw pump for pressure filtration. Collect the obtained copper hydroxide sludge, adjust the pH of the filtrate to 9-10 and then enter the sewage treatment system. At the same time, separate the aluminum hydroxide sludge, and the filtrate enters the sewage treatment system for further treatment.

[0009] Further, in the S1, the dosing ratio of the waste ion liquid to water on the hydrolysis tank is 1:4 - 1:8, and the dosing order of the waste ion liquid and water is to inject water first and then slowly add the ion liquid by self-flow.

[0010] Further, the two-stage alkali treatment in the S3 includes a first stage and a second stage. In the first stage, 20-40wt% of liquid caustic soda is added to dilute the lower layer of the hydrolyzate, and in the second stage, alkali is continuously added until the pH of the lower layer of the hydrolyzate reaches 12-13.

[0011] Further, the alkali addition in the second stage is liquid caustic soda or flake caustic soda. When liquid caustic soda is used, the concentration of the liquid caustic soda is 20-40 wt%. When flake caustic soda is used, the dosing ratio of the waste ionic liquid to water in the hydrolysis tank in S1 needs to be controlled at 1:6-1:8.

[0012] Compared with the prior art, the present invention provides a process and equipment for the resource utilization of waste ionic liquid, having the following beneficial effects: 1. For the process and equipment for the resource utilization of the waste ionic liquid, through the hydrolysis treatment process, the waste ionic liquid is first subjected to controllable hydrolysis and dilution in the hydrolysis tank. By adopting the dosing sequence of first injecting industrial water and then slowly and self-flowingly adding the waste ionic liquid, violent reactions during the mixing of the waste ionic liquid and water are avoided, the safety of the operation is ensured, and the safety risk problem in the process of treating the waste ionic liquid is effectively solved.

[0013] 2. For the process and equipment for the resource utilization of the waste ionic liquid, through the treatment process of "oil separation, neutralization precipitation, and pressure filtration", oil-water separation is achieved through the oil separation tank and the upper oil phase is recovered. The lower water phase is transferred to the reaction tank through the buffer tank, alkali is added to adjust the pH to form copper hydroxide precipitation, and finally copper hydroxide products are obtained through pressure filtration. The filtrate is sent to the sewage treatment system, realizing the resource utilization of harmful components, and having the characteristics of safe operation and high recovery rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of a partial structure of the present invention.

[0015] In the figure: 1. Hydrolysis tank; 2. Three-stage oil separation tank; 3. Buffer tank; 4. Reaction tank; 5. Filter press. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0016] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0017] Example 1: Please refer to Figure 1 , a waste ionic liquid resource utilization device in this embodiment includes a hydrolysis tank 1, a three-stage oil separation tank 2, a buffer tank 3, a reaction tank 4, and a filter press 5. Monitoring instruments are provided in the hydrolysis tank 1, the buffer tank 3, and the reaction tank 4, and conveying equipment is provided on the hydrolysis tank 1, the buffer tank 3, and the reaction tank 4.

[0018] Among them, the monitoring instruments include an on-line pH meter and a liquid level meter. The on-line pH meter is fixedly installed inside the reaction tank 4, and the liquid level meter is fixedly installed inside the buffer tank 3. The on-line pH meter can monitor the pH value of the solution in the reaction tank in real time, providing an accurate basis for adjusting the dosage of liquid caustic soda, ensuring that the neutralization reaction can proceed accurately, facilitating the full precipitation of copper, aluminum and other ions, and improving the recovery rate and purity of copper. The liquid level meter can monitor the height of the lower aqueous phase in the buffer tank 3 in real time, enabling the operator to timely grasp the storage volume of the hydrolyzate and reasonably arrange the pumping operation to the reaction tank 4, ensuring the continuity and stability of the entire process. The conveying equipment includes a metering pump, a screw pump and two centrifugal pumps. The two centrifugal pumps are respectively connected to the discharge port of the hydrolysis tank 1 and the discharge port of the buffer tank 3. The centrifugal pump in the hydrolysis tank 1 is connected to the three-stage oil separation tank 2, and the centrifugal pump in the buffer tank 3 is connected to the feed port of the reaction tank 4. The centrifugal pumps are respectively used for the discharge conveying of the hydrolysis tank and the buffer tank 3, ensuring the smooth flow of materials between different equipment and improving the operation efficiency of the process. The screw pump is respectively connected to the discharge port of the reaction tank 4 and the feed port of the filter press 5. The screw pump can stably convey the slurry in the reaction tank 4 to the filter press 5, adapting to the characteristics of the slurry and ensuring the smooth progress of the solid-liquid separation process. The metering pump is connected to the reaction tank 4. The metering pump can accurately control the feeding rate and volume of liquid caustic soda, avoiding problems such as insufficient reaction or cost waste caused by improper addition of alkali solution. A skimmer is installed on the three-stage oil separation tank 2. Stirring devices are provided on both the hydrolysis tank 1 and the reaction tank 4. A diversion pipe connected to the buffer tank 3 is installed at the bottom of the three-stage oil separation tank 2.

[0019] In addition, the stirring device is a paddle stirrer. The paddle stirrer can fully mix industrial water with waste ionic liquid, alkali liquid with the lower-layer hydrolyzate, ensuring the uniform and full progress of the hydrolysis reaction and the neutralization reaction, improving the reaction efficiency, enabling copper, aluminum and other ions to form hydroxide precipitates more completely, and thus increasing the recovery rate of copper. A cooling jacket is provided on the hydrolysis tank 1. The cooling jacket can effectively control the temperature of the hydrolysis reaction, preventing adverse effects on the equipment and the reaction caused by excessive temperature due to reaction heat release, ensuring the stability and safety of the reaction. The feed port of the hydrolysis tank 1 is a self-flow type anti-splash structure. The design of the self-flow type anti-splash feed port can reduce the splashing of waste ionic liquid during the feeding process, avoid material loss and environmental pollution, and at the same time ensure the safety and stability of the feeding process. The bottom of the hydrolysis tank 1, the buffer tank 3 and the reaction tank 4 all adopt a conical structure and are provided with high-pressure backwashing interfaces. The conical structure at the bottom is convenient for the aggregation and discharge of bottom sediments. The high-pressure backwashing interface facilitates high-pressure backwashing, which can effectively clean the bottom sediments, prevent sediment accumulation from affecting the normal operation of the equipment and subsequent process operations, and improve the service life of the equipment and the reliability of the process.

[0020] It should be noted that inclined plate packings are provided in each stage of the three-stage oil separation tank 2. The oil collection tank at the end of the three-stage oil separation tank 2 is connected to the incineration system. A suspended solid interception net is arranged at the water outlet of the three-stage oil separation tank 2. The inclined plate packings arranged in each stage of the oil separation tank increase the separation area of oil droplets and water, shorten the floating distance of oil droplets, significantly accelerate the oil-water separation speed, improve the separation efficiency. The oil collection tank at the end is connected to the incineration system, which can properly treat the collected floating oil, realize the recycling of resources, and at the same time reduce environmental pollution. The suspended solid interception net arranged at the water outlet can effectively prevent suspended solids from entering the buffer tank 3, avoid blocking the pipeline and affecting subsequent reactions, and ensure the smooth progress of the process.

[0021] Example 2: Please refer to Figure 1 , on the basis of Example 1, a process for the resource utilization of waste ionic liquid includes the following steps: S1. Hydrolysis treatment: Inject industrial water into the hydrolysis tank 1, then place the waste ionic liquid storage container above the feed inlet of the hydrolysis tank 1 and connect it through a pipeline. Open the bottom valve of the waste ionic liquid storage container to make the waste ionic liquid flow into the hydrolysis tank 1. The dosing ratio of the waste ionic liquid to water is 1:4 - 1:8. At the same time, start the stirring device to fully mix the industrial water and the waste ionic liquid, and stop stirring after the reaction ends. S2. Oil-water separation: Start the centrifugal pump to pump the hydrolyzate in the hydrolysis tank 1 into the three-stage oil separation tank 2. Using the gravity separation principle of the three-stage oil separation tank 2, the floating oil with a smaller density slowly floats to the liquid surface. The lower water phase flows into the buffer tank 3 by self-flow through the bottom diversion pipe of the tank, and regularly start the oil scraper to collect the floating oil on the upper layer and store it in a special container. S3. Neutralization reaction: The lower-layer hydrolyzate is temporarily stored in the buffer tank 3, and the liquid level gauge in the buffer tank 3 is used to monitor the height of the lower water phase. When the reaction tank 4 meets the treatment conditions, start the centrifugal pump to pump the lower-layer hydrolyzate in the buffer tank 3 into the reaction tank 4 until the lower-layer hydrolyzate reaches 70% - 80% of the volume of the reaction tank 4. Add liquid caustic soda to the reaction tank 4, and control the dosing of liquid caustic soda through a metering pump for two-stage alkali treatment. In the first stage, add 20 - 40 wt% liquid caustic soda to dilute the lower-layer hydrolyzate. In the second stage, continuously add liquid caustic soda with a concentration of 20 - 40 wt% until the pH of the lower-layer hydrolyzate reaches 12 - 13. At the same time, start the stirring device to mix the alkali solution and the lower-layer hydrolyzate evenly. Use the on-line pH meter on the reaction tank 4 to monitor the pH value of the solution in real time, and copper, aluminum and other ions in the solution are fully formed into hydroxide precipitates. The reaction formulas are Cu²⁺ + 2OH⁻ → Cu(OH)2↓ and Al³⁺ + 3OH⁻ → Al(OH)3↓. S4. Solid-liquid separation: After the neutralization reaction is completed, the slurry in the reaction tank 4 is transported to the filter press 5 through a screw pump for pressure filtration. The obtained copper hydroxide sludge is collected, and the filtrate is adjusted to a pH of 9 - 10 and then enters the sewage treatment system. At the same time, aluminum hydroxide sludge is separated, and the filtrate enters the sewage treatment system for further treatment.

[0022] Example 3: Please refer to Figure 1 , on the basis of Example 1, a process for the resource utilization of waste ionic liquid includes the following steps: S1. Hydrolysis treatment: Inject industrial water into the hydrolysis tank 1, then place the waste ionic liquid storage container above the feed inlet of the hydrolysis tank 1 and connect it through a pipeline. Open the bottom valve of the waste ionic liquid storage container to allow the waste ionic liquid to flow into the hydrolysis tank 1. The dosing ratio of the waste ionic liquid to water is 1:6 - 1:8. At the same time, start the stirring device to fully mix the industrial water and the waste ionic liquid. After the reaction ends, stop the stirring. S2. Oil-water separation: Start the centrifugal pump and pump the hydrolysis liquid in the hydrolysis tank 1 into the three-stage oil separation tank 2. Utilize the gravity separation principle of the three-stage oil separation tank 2 to allow the lighter floating oil to slowly float to the liquid surface. The lower water phase flows through the bottom guide pipe of the tank to the buffer tank 3 by self-flow. Regularly start the oil scraper to collect the floating oil on the upper layer and store it in a special container. S3. Neutralization reaction: The lower hydrolysis liquid is temporarily stored in the buffer tank 3, and the liquid level gauge in the buffer tank 3 is used to monitor the height of the lower water phase. When the reaction tank 4 meets the treatment conditions, start the centrifugal pump to pump the lower hydrolysis liquid in the buffer tank 3 into the reaction tank 4 until the lower hydrolysis liquid reaches 70% - 80% of the volume of the reaction tank 4. Add liquid caustic soda to the reaction tank 4, and control the dosing of liquid caustic soda through a metering pump for two-stage alkali treatment. At the same time, start the stirring device. In the first stage, add 20 - 40 wt% liquid caustic soda to dilute the lower hydrolysis liquid. In the second stage, add flake caustic soda until the pH of the lower hydrolysis liquid reaches 12 - 13 to make the alkali liquid and the lower hydrolysis liquid mix evenly. Use the on-line pH meter on the reaction tank 4 to monitor the pH value of the solution in real time, so that copper, aluminum and other ions in the solution fully form hydroxide precipitates. The reaction formulas are Cu²⁺ + 2OH⁻ → Cu(OH)2↓ and Al³⁺ + 3OH⁻ → Al(OH)3↓. S4. Solid-liquid separation: After the neutralization reaction is completed, pump the slurry in the reaction tank 4 into the filter press 5 through a screw pump for pressure filtration. Collect the obtained copper hydroxide sludge, and after adjusting the pH of the filtrate to 9 - 10, it enters the sewage treatment system. At the same time, separate the aluminum hydroxide sludge, and the filtrate enters the sewage treatment system for further treatment.

[0023] Among them, by first injecting industrial water and then slowly adding the waste ionic liquid by self-flow, this dosing sequence can avoid violent reactions when the waste ionic liquid is mixed with water and ensure the safety of the operation. In addition, through the gravity separation principle and the action of the oil scraper in the three-stage oil separation tank 2, the floating oil can be efficiently recovered, reducing the impact of oil on the neutralization reaction and sewage treatment in the subsequent treatment process, reducing the treatment load. At the same time, the recovered floating oil can be further processed and utilized to achieve the recycling of resources and create certain economic benefits. In addition, 20-40 wt% of liquid caustic soda is added in the first stage to dilute the lower-layer hydrolyzed solution, gradually increasing the pH value of the solution. First, some impurity ions are precipitated to reduce the influence of impurities on copper precipitation. In the second stage, alkali is continuously added until the pH reaches 12-13, so that copper ions are fully converted into copper hydroxide precipitate, and aluminum ions are converted into aluminum hydroxide precipitate, realizing the separation of copper and aluminum, improving the purity of copper. Moreover, the hydrolysis ratio can be adjusted according to the type of alkali used, enhancing the flexibility of the process and the adaptability to different alkali sources, ensuring the smooth progress of the neutralization reaction, and improving the copper recovery rate; It should be noted that after the neutralization reaction is completed, solid-liquid separation is carried out by the filter press 5, which can efficiently separate the copper hydroxide sludge and the filtrate. The obtained copper hydroxide sludge has a high purity, which is convenient for subsequent recycling, realizing the reuse of copper resources and improving economic benefits. After the filtrate is adjusted to a pH of 9-10, it enters the sewage treatment system and is discharged up to standard after further treatment, avoiding environmental pollution, meeting the requirements of environmental protection and sustainable development, and at the same time reducing the waste liquid disposal cost.

[0024] It should be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or also includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising a..." does not exclude the presence of additional identical elements in the process, method, article or device comprising the element.

[0025] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A waste ionic liquid resource utilization device, comprising a hydrolysis tank (1), a three-stage oil separator (2), a buffer tank (3), a reaction tank (4) and a filter press (5), characterized in that: Monitoring instruments are provided in the hydrolysis tank (1), buffer tank (3) and reaction tank (4), and conveying equipment is provided on the hydrolysis tank (1), buffer tank (3) and reaction tank (4).

2. The equipment for resource utilization of waste ionic liquid according to claim 1, wherein: The monitoring instruments include an on-line pH meter and a liquid level meter. The on-line pH meter is fixedly installed inside the reaction tank (4), and the liquid level meter is fixedly installed inside the buffer tank (3). The conveying equipment includes a metering pump, a screw pump and two centrifugal pumps. The two centrifugal pumps are respectively connected to the discharge port of the hydrolysis tank (1) and the discharge port of the buffer tank (3). The centrifugal pump in the hydrolysis tank (1) is connected to the three-stage oil separation tank (2), and the centrifugal pump in the buffer tank (3) is connected to the feed port of the reaction tank (4). The screw pump is respectively connected to the discharge port of the reaction tank (4) and the feed port of the filter press (5). The metering pump is connected to the reaction tank (4). An oil skimmer is installed on the three-stage oil separation tank (2). Stirring devices are provided on both the hydrolysis tank (1) and the reaction tank (4). A diversion pipe connected to the buffer tank (3) is installed at the bottom of the three-stage oil separation tank (2).

3. The equipment for resource utilization of waste ionic liquid according to claim 2, characterized in that: The stirring device is a paddle stirrer. A cooling jacket is provided on the hydrolysis tank (1). The feed port of the hydrolysis tank (1) is a self-flow anti-splash structure. The bottoms of the hydrolysis tank (1), buffer tank (3) and reaction tank (4) all adopt a conical structure and are provided with high-pressure backwashing interfaces.

4. The equipment for resource utilization of waste ionic liquid according to claim 1, characterized in that: In each stage of the three-stage oil separation tank (2), inclined plate fillers are provided. The oil collection tank at the end of the three-stage oil separation tank (2) is connected to the incineration system. A suspended matter interception net is provided at the water outlet of the three-stage oil separation tank (2).

5. The process for resource utilization of waste ionic liquid of the device according to any one of claims 1-4, characterized in that: It includes the following steps: S1. Hydrolysis treatment: Inject industrial water into the hydrolysis tank (1), then place the waste ion liquid storage container above the feed port of the hydrolysis tank (1) and connect it through a pipeline. Open the bottom valve of the waste ion liquid storage container to make the waste ion liquid flow into the hydrolysis tank (1). At the same time, start the stirring device to fully mix the industrial water and the waste ion liquid. After the reaction ends, stop the stirring. S2. Oil-water separation: Start the centrifugal pump to pump the hydrolysis liquid in the hydrolysis tank (1) into the three-stage oil separation tank (2). Utilize the gravity separation principle of the three-stage oil separation tank (2) to make the floating oil with a smaller density slowly float to the liquid surface. The lower water phase flows into the buffer tank (3) by self-flow through the diversion pipe at the bottom of the tank. Regularly start the oil skimmer to collect the floating oil on the upper layer and store it in a special container. S3. Neutralization reaction: The lower layer of hydrolysis liquid is temporarily stored in the buffer tank (3), and the liquid level meter in the buffer tank (3) is used to monitor the height of the lower water phase. When the reaction tank (4) has the processing conditions, start the centrifugal pump to pump the lower layer of hydrolysis liquid in the buffer tank (3) into the reaction tank (4) until the lower layer of hydrolysis liquid reaches 70%-80% of the volume of the reaction tank (4). Add liquid caustic soda to the reaction tank (4), and control the rate and volume of the added liquid caustic soda through the metering pump to carry out two-stage alkali treatment. At the same time, start the stirring device to make the caustic soda solution and the lower layer of hydrolysis liquid mix evenly. Use the on-line pH meter on the reaction tank (4) to monitor the pH value of the solution in real time, and make the copper, aluminum and other ions in the solution fully form hydroxide precipitates. S4. Solid-liquid separation: After the neutralization reaction is completed, the slurry in the reaction tank (4) is pumped to the filter press (5) by a screw pump for pressure filtration. The obtained copper hydroxide sludge is collected, and the filtrate is adjusted back to pH 9 - 10 and then enters the sewage treatment system. Meanwhile, the aluminum hydroxide sludge is separated, and the filtrate enters the sewage treatment system for further treatment.

6. The process for resource utilization of waste ionic liquid according to claim 5, characterized in that: In S1, the dosing ratio of the waste ionic liquid to water in the hydrolysis tank (1) is 1:4 - 1:8, and the dosing order of the waste ionic liquid and water is to first inject water and then slowly add the ionic liquid by gravity flow.

7. A process for the resource utilization of waste ionic liquid according to claim 6, characterized in that: The two-stage alkali treatment in S3 includes a first stage and a second stage. In the first stage, 20 - 40 wt% liquid alkali is added to dilute the lower-layer hydrolysis solution, and in the second stage, alkali is continuously added until the pH of the lower-layer hydrolysis solution reaches 12 - 13.

8. A process for the resource utilization of waste ionic liquid according to claim 7, characterized in that: In the second stage, the added alkali is liquid alkali or flake alkali. When using liquid alkali, the concentration of the liquid alkali is 20 - 40 wt%; when using flake alkali, the dosing ratio of the waste ionic liquid to water in the hydrolysis tank (1) in S1 needs to be controlled at 1:6 - 1:8.

Images