Recovery device of iron-containing waste hydrochloric acid

Abstract

The utility model relates to an iron-containing waste hydrochloric acid recovery device which comprises a feeding tank, a feeding pump I, an MF membrane component, an NF storage tank, a feeding pump II, an NF membrane component, a feed liquid circulating tank, a circulating pump, a membrane distiller and a hydrochloric acid condensation and collection component which are sequentially communicated through a conveying pipeline, the stock solution inlet is communicated with an iron-containing waste hydrochloric acid conveying pipeline, the stock solution outlet is communicated with an inlet of the feeding pump I, the concentrated water backflow inlet is communicated with a concentrated water outlet of the MF membrane assembly through a backflow pipeline, a produced water outlet of the MF membrane assembly is communicated with an inlet of the NF storage tank, and a produced water outlet of the NF membrane assembly is communicated with a hydrochloric acid recycling pipeline; a concentrated water outlet of the NF membrane assembly is communicated with an inlet of the feed liquid circulating tank, and an outlet of the feed liquid circulating tank is communicated with an inlet of the circulating pump. The method has the advantages that hydrochloric acid and ferric chloride in the iron-containing waste hydrochloric acid can be effectively separated and respectively recycled, no other agents are introduced or redundant waste is generated, and the operation is stable.

Description

Technical Field

[0001] This utility model belongs to the field of resource recycling and reuse technology, specifically relating to a device for recovering iron-containing waste hydrochloric acid. Background Technology

[0002] The new energy vehicle industry is showing a positive trend of "accelerated improvement" in both market size and development quality. This has made battery recycling a new topic, leading to the development of lithium battery recycling and processing equipment to handle these used lithium batteries. Proper battery disposal is conducive to resource reuse, achieving a win-win situation for both environmental protection and economic efficiency. Conversely, improper disposal can easily pollute the surrounding environment with heavy metals and acidic waste liquids from batteries, violating the original intention of protecting the environment and conserving resources.

[0003] Waste batteries from new energy vehicles can achieve high recycling rates through tiered utilization. Using physical and mechanical methods to recycle, discharge, disassemble, process, and remanufacture waste lithium batteries can reduce environmental pollution and achieve resource recycling and sustainable development. In the wet process of lithium battery recycling, concentrated hydrochloric acid is used to back-extract iron ions, producing waste hydrochloric acid containing iron ions. This waste hydrochloric acid has a concentration of 4-5 mol / L, an iron content of 800-1000 ppm, and also contains small amounts of oily substances (mainly sulfonated kerosene). This iron-containing waste hydrochloric acid is unusable and may require large amounts of alkali for neutralization. Therefore, from both economic and environmental perspectives, the recycling of waste hydrochloric acid must be considered.

[0004] Currently, the treatment methods for iron-containing waste hydrochloric acid generally include neutralization, evaporation, and resin ion exchange. Most of them adopt the more economical and suitable resin ion exchange method. However, the biggest problem with using resin for ion exchange is that the resin is very easy to saturate and needs to be frequently regenerated, which also generates a certain amount of waste acid. In summary, only about 80% of the hydrochloric acid can be reused after treatment, and a large amount of waste hydrochloric acid still needs to be treated separately. Utility Model Content

[0005] This utility model provides a device for recovering iron-containing waste hydrochloric acid, aiming to provide a full membrane hydrochloric acid recovery and utilization device with low manufacturing cost, compact structure, flexible installation and easy management and use.

[0006] The technical solution of this utility model to solve the above-mentioned technical problems is as follows: A recovery device for iron-containing waste hydrochloric acid includes a feed tank, a feed pump one, an MF membrane module, an NF storage tank, a feed pump two, an NF membrane module, a feed liquid circulation tank, a circulation pump, a membrane distillation unit, and a hydrochloric acid condensation and collection assembly connected in sequence through a conveying pipeline. The feed tank has a raw liquid inlet, a raw liquid outlet, and a concentrated water reflux inlet. The raw liquid inlet is connected to the iron-containing waste hydrochloric acid conveying pipeline. The raw liquid outlet is connected to the inlet of the feed pump one. The concentrated water reflux inlet is connected to the concentrated water outlet of the MF membrane module through a reflux pipeline. The product water outlet of the MF membrane module is connected to the inlet of the NF storage tank. The product water outlet of the NF membrane module is connected to the hydrochloric acid reuse pipeline. The concentrated water outlet of the NF membrane module is connected to the inlet of the feed liquid circulation tank. The outlet of the feed liquid circulation tank is connected to the inlet of the circulation pump. The gas phase outlet of the membrane distillation unit is connected to the hydrochloric acid condensation and collection assembly. The liquid phase outlet of the membrane distillation unit is connected to the reflux inlet of the feed liquid circulation tank.

[0007] Based on the above technical solution, the present invention can be further improved as follows.

[0008] Furthermore, a valve is provided on the conveying pipeline between the feed tank and the feed pump, a valve is provided on the conveying pipeline between the feed pump and the MF membrane module, and a pressure gauge is provided on the return pipeline.

[0009] Furthermore, valves four and five are respectively provided on the conveying pipes connected to the inlet and outlet of the feed pump two, and pressure gauge three is provided on the conveying pipe between valve five and the NF membrane module.

[0010] Furthermore, a valve six and a pressure gauge four are provided on the conveying pipeline between the concentrate outlet of the NF membrane module and the inlet of the feed circulation tank.

[0011] Furthermore, at least one oil removal mechanism is provided on the conveying pipeline between the concentrate outlet of the NF membrane module and the inlet of the feed circulation tank.

[0012] Furthermore, the oil removal mechanism is an oil removal filter containing an oil removal agent filter layer.

[0013] Furthermore, the oil removal mechanism consists of two sets arranged in parallel, and each set of the oil removal mechanism includes an oil removal filter and a control valve.

[0014] Furthermore, the liquid circulation tank is equipped with a constant temperature controller.

[0015] Furthermore, the membrane distillation apparatus is equipped with a pressure gauge.

[0016] Furthermore, the hydrochloric acid condensation and collection assembly includes a condenser, a receiving bottle, and a vacuum pump connected in sequence via pipelines.

[0017] Compared with the prior art, the beneficial effects of this utility model are:

[0018] The recycling device provided by this utility model has the advantages of simple structure, low operating cost, high degree of automation, and low equipment failure rate. During use, it can effectively separate hydrochloric acid and ferric chloride from iron-containing waste hydrochloric acid and recycle them separately without introducing any other reagents or generating excess waste. The operation is stable. After being processed by the recycling device provided by this utility model, both ferric chloride and hydrochloric acid in iron-containing waste hydrochloric acid can be recycled. The whole process can achieve zero emissions and turn waste into treasure. Attached Figure Description

[0019] Figure 1 A schematic diagram of a device for recovering iron-containing waste hydrochloric acid provided by this utility model.

[0020] The attached diagram lists the components represented by each number as follows:

[0021] 1. Feed tank; 2. Feed pump one; 3. MF membrane module; 4. NF storage tank; 5. Feed pump two; 6. NF membrane module; 7. Feed circulation tank; 8. Circulation pump; 9. Membrane distillation unit; 10. Return pipeline; 11. Hydrochloric acid reuse pipeline; 12. Valve one; 13. Valve two; 14. Valve three; 15. Valve four; 16. Valve five; 17. Valve six; 18. Oil removal filter; 19. Thermostat; 20. Condenser; 21. Receiving bottle; 22. Vacuum pump. Detailed Implementation

[0022] The principles and features of this utility model are described below with reference to the accompanying drawings. The examples given are only for explaining this utility model and are not intended to limit the scope of this utility model.

[0023] In the description of this utility model, if terms such as "upper", "lower", "left", "right", "top", "bottom", "inner", and "outer" are used to indicate the orientation or positional relationship, the orientation or positional relationship indicated is based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0024] like Figure 1As shown, this utility model provides a device for recovering iron-containing waste hydrochloric acid, which includes a feed tank 1, a feed pump 2, an MF membrane module 3, an NF storage tank 4, a feed pump 5, an NF membrane module 6, a feed liquid circulation tank 7, a circulation pump 8, a membrane distillation unit 9, and a hydrochloric acid condensation and collection assembly, all connected in sequence via a conveying pipeline. The feed tank 1 has a raw liquid inlet, a raw liquid outlet, and a concentrated water return inlet. The raw liquid inlet is connected to the iron-containing waste hydrochloric acid conveying pipeline, the raw liquid outlet is connected to the inlet of the feed pump 2, and the concentrated water return inlet is connected to a return pipeline. 10 is connected to the concentrate outlet of the MF membrane module 3, the permeate outlet of the MF membrane module 3 is connected to the inlet of the NF storage tank 4, the permeate outlet of the NF membrane module 6 is connected to the hydrochloric acid reuse pipeline 11, the concentrate outlet of the NF membrane module 6 is connected to the inlet of the feed circulation tank 7, the outlet of the feed circulation tank 7 is connected to the inlet of the circulation pump 8, the gas phase outlet of the membrane distillation unit 9 is connected to the hydrochloric acid condensation and collection assembly, and the liquid phase outlet of the membrane distillation unit 9 is connected to the circulation reflux inlet of the feed circulation tank 7.

[0025] It should be noted that the aforementioned MF membrane module can specifically be a tubular ceramic membrane module. The operating pressure inside this membrane module is controlled at 0.1-0.2 MPa. It is a ceramic membrane separation technology using alumina, titanium dioxide, or silicon dioxide, which can adapt to the separation of strongly acidic materials. It belongs to a "cross-flow filtration" type of fluid separation process: First, the feed liquid flows at high speed inside the membrane tube. Then, under pressure, the clarified permeate containing small molecules will quickly flow outward through the membrane in a direction perpendicular to them. As for the turbid concentrate containing large molecules, it will be retained by the membrane. Therefore, the liquid can achieve the purpose of purification, separation, and concentration.

[0026] In addition, the NF membrane in the NF membrane module is a special type of acid-resistant NF membrane, and the operating pressure inside the membrane module is 0.7-1 MPa.

[0027] In one embodiment of this utility model, a valve 12 is provided on the conveying pipeline between the feed tank 1 and the feed pump 2, a valve 13 and a pressure gauge 1 are provided on the conveying pipeline between the feed pump 2 and the MF membrane module 3, and a valve 3 and a pressure gauge 2 are provided on the return pipeline 10.

[0028] In one embodiment of this utility model, valves 15 and 16 are respectively provided on the conveying pipes connected to the inlet and outlet of the feed pump 2 5, and pressure gauge 3 is provided on the conveying pipe between valve 5 16 and the NF membrane module 6.

[0029] In one embodiment of this utility model, a valve 17 and a pressure gauge 4 are provided on the conveying pipeline between the concentrate outlet of the NF membrane module 6 and the inlet of the feed circulation tank 7.

[0030] In one embodiment of the present invention, at least one set of oil removal mechanisms is provided on the conveying pipeline between the concentrate outlet of the NF membrane module 6 and the inlet of the feed circulation tank 7.

[0031] In one embodiment of this utility model, the oil removal mechanism is an oil removal filter 18 containing an oil removal agent filter layer. There are two sets of oil removal mechanisms arranged in parallel, and each set includes an oil removal filter 18 and a control valve.

[0032] It should be noted that the two sets of oil removal mechanisms can be switched as needed to handle fault repairs and achieve uninterrupted operation.

[0033] In one embodiment of this utility model, a constant temperature controller 19 is provided on the liquid circulation tank 7.

[0034] It should be noted that the liquid circulation tank is equipped with a thermostat, which can keep the liquid temperature constant at 60℃.

[0035] In one embodiment of this utility model, a pressure gauge is provided on the membrane distillation apparatus 9.

[0036] In one embodiment of the present invention, the hydrochloric acid condensation and collection assembly includes a condenser 20, a receiving bottle 21, and a vacuum pump 22 connected in sequence by pipes.

[0037] It should be noted that the vacuum pump provides negative pressure, and hydrochloric acid evaporates on the right side of the membrane still. After being condensed by the condenser, relatively pure and qualified hydrochloric acid without impurities such as ferric chloride is collected in the receiving bottle for resource recovery. Ferric chloride can be recovered on the left side of the membrane still.

[0038] In practice, the iron-containing waste hydrochloric acid recovery device provided by this utility model was used to recover the iron-containing waste hydrochloric acid, as detailed below:

[0039] Example 1

[0040] Project 1: Recycling and utilization of iron-containing waste hydrochloric acid in a wet process for lithium battery recycling.

[0041] Content of various metal ions in iron-containing waste hydrochloric acid to be treated (unit: ppm)

[0042] Fe Zn Ni Cu Cd 289.3 0.087 15.73 8.96 0.003

[0043] During the treatment process, the operating differential pressure of the MF membrane module was controlled at 0.13 MPa, and the operating pressure of the NF membrane module was controlled at 0.72 MPa. The content of various metal ions in the treated iron-containing waste hydrochloric acid (unit: ppm)

[0044] Fe Zn Ni Cu Cd 26.1 0.056 1.695 0.939 0.003

[0045] 95.8% of the waste hydrochloric acid was recycled after treatment.

[0046]

[0047] Example 2

[0048] Project 2: Recycling of iron-containing waste hydrochloric acid from lithium batteries.

[0049] Content of various metal ions in iron-containing waste hydrochloric acid to be treated (unit: ppm)

[0050] Fe Zn Ni Cu Cd 217.4 0.523 11.65 6.57 0.003

[0051] During the treatment process, the operating differential pressure of the MF membrane module was controlled at 0.15 MPa, and the operating pressure of the NF membrane module was controlled at 0.75 MPa. The content of each metal ion in the treated iron-containing waste hydrochloric acid (unit: ppm)

[0052] Fe Zn Ni Cu Cd 18.9 0.497 1.259 0.831 0.003

[0053] 96.2% of the waste hydrochloric acid was recycled after treatment.

[0054]

[0055] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. An apparatus for recovering iron-containing spent hydrochloric acid, characterized by comprising: The application relates to a device for recycling waste hydrochloric acid, which comprises a feeding tank (1), a feeding pump (2), an MF membrane assembly (3), an NF storage tank (4), a feeding pump (2), an NF membrane assembly (6), a liquid circulating tank (7), a circulating pump (8), a membrane distiller (9) and a hydrochloric acid condensing and collecting assembly which are sequentially connected through conveying pipelines, wherein the feeding tank (1) is provided with a raw liquid inlet, a raw liquid outlet and a concentrated water backflow inlet, the raw liquid inlet is communicated with a conveying pipeline of waste hydrochloric acid containing iron, the raw liquid outlet is communicated with an inlet of the feeding pump (2), the concentrated water backflow inlet is communicated with a concentrated water outlet of the MF membrane assembly (3) through a backflow pipeline (10), a water outlet of the MF membrane assembly (3) is communicated with an inlet of the NF storage tank (4), a water outlet of the NF membrane assembly (6) is communicated with a hydrochloric acid recycling pipeline (11), a concentrated water outlet of the NF membrane assembly (6) is communicated with an inlet of the liquid circulating tank (7), an outlet of the liquid circulating tank (7) is communicated with an inlet of the circulating pump (8), a gas phase outlet of the membrane distiller (9) is communicated with the hydrochloric acid condensing and collecting assembly, and a liquid phase outlet of the membrane distiller (9) is communicated with a circulating backflow inlet of the liquid circulating tank (7).

2. A device for recovering iron-containing spent hydrochloric acid according to claim 1, characterized in that, A valve (12) is arranged on a conveying pipeline between the feeding tank (1) and the feeding pump (2), a valve (13) and a pressure gauge (1) are arranged on a conveying pipeline between the feeding pump (2) and the MF membrane assembly (3), and a valve (14) and a pressure gauge (2) are arranged on the backflow pipeline (10).

3. A device for recovering iron-containing spent hydrochloric acid according to claim 1, characterized in that, Valves (15) and (16) are respectively arranged on conveying pipelines connected to an inlet and an outlet of the feeding pump (2), and a pressure gauge (3) is arranged on a conveying pipeline between the valve (16) and the NF membrane assembly (6).

4. A device for recovering iron-containing spent hydrochloric acid according to claim 1, characterized in that, A valve (17) and a pressure gauge (4) are arranged on a conveying pipeline between a concentrated water outlet of the NF membrane assembly (6) and an inlet of the liquid circulating tank (7).

5. A device for recovering iron-containing spent hydrochloric acid according to claim 1, characterized in that, At least one set of oil removal mechanisms is arranged on a conveying pipeline between the concentrated water outlet of the NF membrane assembly (6) and the inlet of the liquid circulating tank (7).

6. A device for recovering iron-containing spent hydrochloric acid according to claim 5, characterized in that, The oil removal mechanism is an oil removal filter (18) containing an oil removal agent filter layer.

7. A device for recovering iron-containing spent hydrochloric acid according to claim 6, characterized in that, Two sets of the oil removal mechanisms are arranged in parallel, and each set of the oil removal mechanisms comprises the oil removal filter (18) and a control valve.

8. A device for recovering iron-containing spent hydrochloric acid according to claim 1, characterized in that, A constant temperature controller (19) is arranged on the liquid circulating tank (7).

9. A device for recovering iron-containing spent hydrochloric acid according to claim 1, characterized in that, A pressure gauge (5) is arranged on the membrane distiller (9).

10. A device for recovering iron-containing spent hydrochloric acid according to any one of claims 1 to 9, characterized in that, The hydrochloric acid condensing and collecting assembly comprises a condenser (20), a receiving bottle (21) and a vacuum pump (22) which are sequentially connected through pipelines.

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