A zinc chloride wastewater recovery apparatus

Abstract

This utility model discloses a wastewater recovery device for zinc chloride, relating to the field of wastewater recovery and treatment technology. It includes a pretreatment unit, a purification unit, a zinc recovery unit, and an electrolytic refining unit connected in sequence. These units are connected sequentially via pipelines. The pretreatment unit includes a filtration device and a pH adjustment device. The purification unit includes a chemical precipitation device and an ion exchange device. The chemical precipitation device includes a chemical precipitation tank, a precipitant addition port, and a slag discharge port. This technology can be applied to various industrial enterprises that generate zinc chloride wastewater, such as electroplating plants, new energy battery factories, and chemical synthesis plants. With increasingly stringent environmental protection requirements and growing awareness of resource recycling, this technology has broad market application prospects, bringing not only economic benefits to enterprises but also significant social and environmental benefits.

Description

Technical Field

[0001] This utility model relates to the field of wastewater recycling and treatment technology, and in particular to a wastewater recycling device for zinc chloride. Background Technology

[0002] Zinc chloride is widely used in industries such as organic synthesis, electroplating, and new energy electronics manufacturing. However, the production of these products generates a large amount of wastewater containing zinc chloride. Direct discharge not only wastes zinc resources but also causes serious environmental damage due to pollutants such as heavy metal ions contained in the wastewater. Currently, although various zinc chloride wastewater treatment technologies exist, existing treatment equipment often suffers from problems such as complex structure, insufficient connection between treatment stages, low treatment efficiency, and insufficient resource recovery, making it difficult to meet the demand for efficient, environmentally friendly, and low-cost zinc chloride wastewater treatment. Therefore, there is an urgent need to design a wastewater recovery device with a reasonable structure, simple operation, and the ability to achieve efficient zinc chloride recovery. Utility Model Content

[0003] To achieve the above objectives, this utility model provides the following technical solution: a wastewater recovery device for zinc chloride, comprising a pretreatment unit, a purification unit, a zinc recovery unit, and an electrolytic refining unit connected in sequence; the pretreatment unit, purification unit, zinc recovery unit, and electrolytic refining unit are connected in sequence via pipelines; the pretreatment unit includes a filtration device and a pH adjustment device; the purification unit includes a chemical precipitation device and an ion exchange device; the chemical precipitation device includes a chemical precipitation tank, a precipitant addition port, and a slag discharge port; the slag discharge port is located at the upper end of the chemical precipitation tank and at the bottom end of the chemical precipitation tank; the ion exchange device has an ion exchange column inside, and the ion exchange column is filled with ion exchange resin; the zinc recovery unit includes a concentration crystallization device and a recrystallization device; the concentration crystallization device has a heating device and a cooling device; the electrolytic refining unit includes an electrolytic cell, which has a graphite anode and a pure zinc cathode; the electrolytic refining unit is also electrically connected to a current density adjustment device and an electrolysis time control device.

[0004] Preferably, the pretreatment unit, the impurity removal unit, the zinc recovery unit, and the electrolytic refining unit are all connected by pipelines, and each pipeline is equipped with a valve.

[0005] Preferably, the ion exchange resin is a strongly acidic ion exchange resin.

[0006] Preferably, the filtration device is a filter.

[0007] Preferably, the pH adjustment device includes a pH adjustment tank, an acid inlet, an alkali inlet, and a stirrer; the acid inlet and alkali inlet are respectively located at the upper end of the pH adjustment tank, the stirrer is installed on the pH adjustment tank, and a pH detector is installed inside the pH adjustment tank.

[0008] Beneficial effects: Compared with the prior art, the beneficial effects of this utility model are:

[0009] 1. High resource utilization rate: It can effectively recover metallic zinc from zinc chloride waste liquid and convert it into usable high-purity products, thereby improving the utilization rate of zinc resources and reducing the production cost of recycling.

[0010] 2. Significant environmental benefits: By treating the waste liquid, the emission of pollutants such as heavy metal ions is reduced, thus mitigating the harm to the environment and meeting the requirements of sustainable development.

[0011] 3. High product quality: After multiple processing and purification steps, the zinc chloride product obtained has a high purity, which can meet the needs of different fields. If further electrolyzed, high-purity metallic zinc can also be obtained.

[0012] 4. The process is highly adaptable. The technology is relatively flexible and can be adjusted according to the composition and impurity content of the waste liquid, making it suitable for the treatment of zinc chloride waste liquid from different sources. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the structure of a zinc chloride wastewater recovery device proposed in this utility model.

[0014] In the attached diagram: 1-Pretreatment unit, 101-Filter device, 102-pH adjustment device, 1021-pH adjustment tank, 1022-Acid addition port, 1023-Alkali addition port, 1024-Agitator, 1025-pH detector, 2-Impurity removal unit, 201-Chemical precipitation device, 2011-Chemical precipitation tank, 2012-Flocculant addition port, 2013-Slag discharge port, 202-Ion exchange device, 3-Zinc recovery unit, 301-Concentration and crystallization device, 302-Recrystallization device, 4-Electrorefining unit, 401-Electrolytic cell, 402-Graphite anode, 403-Pure zinc cathode, 5-Current density adjustment device, 6-Electrolysis time control device. Detailed Implementation

[0015] The technical solution of this patent will be further described in detail below with reference to specific embodiments.

[0016] Example

[0017] Please refer to the accompanying drawings in the specification. In this embodiment of the present invention, a wastewater recovery device for zinc chloride includes a pretreatment unit 1, a purification unit 2, a zinc recovery unit 3, and an electrolytic refining unit 4 connected in sequence. The pretreatment unit 1, purification unit 2, zinc recovery unit 3, and electrolytic refining unit 4 are connected in sequence via pipelines. The pretreatment unit 1 includes a filtration device 101 and a pH adjustment device 102. The purification unit 2 includes a chemical precipitation device 201 and an ion exchange device 202. The chemical precipitation device 201 includes a chemical precipitation tank 2011, a precipitant addition port 2012, and a slag discharge port 2013. The outlet 2013 is located at the upper end of the chemical precipitation tank 2011, and the slag discharge outlet 2013 is located at the bottom end of the chemical precipitation tank 2011. The ion exchange device 202 is equipped with an ion exchange column, and the interior of the ion exchange column is filled with ion exchange resin. The zinc recovery unit 3 includes a concentration crystallization device 301 and a recrystallization device 302. The concentration crystallization device is equipped with a heating device and a cooling device. The electrolytic refining unit 4 includes an electrolytic cell 401. The electrolytic cell is equipped with a graphite anode 402 and a pure zinc sheet cathode 403. The electrolytic refining unit 4 is also electrically connected to a current density adjustment device 5 and an electrolysis time control device 6.

[0018] The pretreatment unit 1, the impurity removal unit 2, the zinc recovery unit 3, and the electrolytic refining unit 4 are all connected by pipelines, and each pipeline is equipped with a valve.

[0019] The ion exchange resin is a strongly acidic ion exchange resin.

[0020] The filtration device 101 is a filter.

[0021] The pH adjustment device 102 includes a pH adjustment tank 1021, an acid inlet 1022, an alkali inlet 1023, and a stirrer 1024. The acid inlet 1022 and the alkali inlet 1023 are respectively located at the upper end of the pH adjustment tank 1021. The stirrer 1024 is installed on the pH adjustment tank 1021. A pH detector 1025 is installed inside the pH adjustment tank 1021.

[0022] Working principle:

[0023] (1) Pretreatment unit: Filtration, using a filter to pre-filter the zinc chloride waste liquid to remove larger impurities such as solid suspended matter and metal shavings; this can prevent subsequent equipment blockage and ensure the smooth operation of the disposal process; pH adjustment, by adding an appropriate amount of acid or alkali, the pH value of the waste liquid is adjusted to a suitable range, the purpose of which is to precipitate some metal ions (such as iron, aluminum, etc.) in the form of hydroxide precipitates, which is convenient for subsequent separation. After the pH is adjusted, it enters the impurity removal unit.

[0024] (2) Impurity removal unit:

[0025] Chemical precipitation method: Add an appropriate amount of precipitant, such as sodium sulfide, to the pretreated waste liquid. Sodium sulfide reacts with the heavy metal ions in the waste liquid to form insoluble metal sulfide precipitates. The precipitates are separated by filtration, thereby reducing the content of heavy metal ions in the waste liquid. After precipitation, the waste liquid flows into the ion exchange device.

[0026] Ion exchange method: Ion exchange resin is used to further remove impurity ions from the waste liquid. Ion exchange resins with high selectivity for specific ions are selected. For example, strong acid ion exchange resins can remove divalent and polyvalent cations. The waste liquid is passed through an ion exchange column. Impurity metals are adsorbed by the resin, while zinc ions are enriched in the effluent.

[0027] (3) Zinc recovery unit: Concentration and crystallization. The waste liquid after impurity removal is heated and concentrated by a heating device to make the solution supersaturated. Then, it is cooled and crystallized by a cooling device. As the temperature decreases, zinc chloride recrystallizes from the solution and is obtained by filtration, washing and other operations.

[0028] Recrystallization purification: If impurities are present in the zinc chloride obtained in the first step, and high-purity zinc chloride needs to be processed, the zinc chloride needs to be redissolved and recrystallized. The crude zinc chloride crystals are dissolved in an appropriate amount of distilled water, then heated until completely dissolved. The insoluble impurities are filtered out, and the filtrate is cooled and crystallized. After multiple recrystallization operations, high-purity zinc chloride crystals can be obtained.

[0029] (4) Electrolytic refining unit (for producing high-purity metallic zinc): If high-purity metallic zinc is required for production, high-purity zinc chloride crystals are prepared as electrolyte, with graphite as the anode and pure zinc sheet as the cathode, and electrolysis is carried out. During the electrolysis process, zinc ions gain electrons at the cathode and are reduced to metallic zinc, while chloride ions lose electrons at the anode to produce chlorine gas. This reaction can be controlled under appropriate conditions (current density, electrolysis time, etc.) to obtain high-purity metallic zinc at the cathode.

[0030] The above process boasts high resource utilization, effectively recovering metallic zinc from zinc chloride waste liquid and converting it into a usable high-purity product, thereby improving zinc resource utilization and reducing recycling production costs. It offers significant environmental benefits, reducing emissions of heavy metal ions and other pollutants through waste liquid treatment, mitigating environmental harm and aligning with sustainable development requirements. The product quality is high; after multi-step purification, the obtained zinc chloride product has high purity, meeting the needs of various fields. Further electrolysis can yield even higher-purity metallic zinc. The process is highly adaptable; the technology is relatively flexible and can be adjusted according to the composition and impurity content of the waste liquid, making it suitable for treating zinc chloride waste liquid from different sources.

[0031] This technology can be applied to various industrial enterprises that generate zinc chloride waste liquid, such as electroplating plants, new energy battery plants, and chemical synthesis plants. With increasingly stringent environmental protection requirements and growing awareness of resource recycling, this technology has broad market application prospects. It can not only bring economic benefits to enterprises, but also generate good social and environmental benefits.

[0032] The above are merely preferred embodiments of this utility model. It should be noted that, for those skilled in the art, several modifications and improvements can be made without departing from the concept of this utility model, and these should also be considered within the scope of protection of this utility model. These will not affect the implementation effect of this utility model or the practicality of the patent.

Claims

1. A zinc chloride wastewater recovery apparatus, characterized by: The system includes a pretreatment unit (1), a purification unit (2), a zinc recovery unit (3), and an electrolytic refining unit (4) connected in sequence. These units are connected in sequence via pipelines. The pretreatment unit (1) includes a filtration device (101) and a pH adjustment device (102). The purification unit (2) includes a chemical precipitation device (201) and an ion exchange device (202). The chemical precipitation device (201) includes a chemical precipitation tank (2011), a precipitant addition port (2012), and a slag discharge port (2013). The slag discharge port (2013) is located within the chemical precipitation tank. At the upper end of the sedimentation tank (2011), the slag discharge port (2013) is located at the bottom end of the chemical sedimentation tank (2011). The ion exchange device (202) is equipped with an ion exchange column, and the ion exchange column is filled with ion exchange resin. The zinc recovery unit (3) includes a concentration crystallization device (301) and a recrystallization device (302). The concentration crystallization device is equipped with a heating device and a cooling device. The electrolytic refining unit (4) includes an electrolytic cell (401). The electrolytic cell is equipped with a graphite anode (402) and a pure zinc sheet cathode (403). The electrolytic refining unit (4) is also electrically connected to a current density adjustment device (5) and an electrolysis time control device (6).

2. A zinc chloride wastewater recovery apparatus according to claim 1, characterized in that: The pretreatment unit (1), the impurity removal unit (2), the zinc recovery unit (3), and the electrolytic refining unit (4) are all connected by pipelines, and each pipeline is equipped with a valve.

3. The zinc chloride wastewater recovery apparatus according to claim 1, characterized by: The ion exchange resin is a strongly acidic ion exchange resin.

4. The zinc chloride wastewater recovery apparatus according to claim 1, characterized by: The filtration device (101) is a filter.

5. The zinc chloride wastewater recovery apparatus of claim 1, wherein: The pH adjustment device (102) includes a pH adjustment tank (1021), an acid inlet (1022), an alkali inlet (1023), and a stirrer (1024). The acid inlet (1022) and the alkali inlet (1023) are respectively located at the upper end of the pH adjustment tank (1021). The pH adjustment tank (1021) is equipped with a stirrer (1024). The pH adjustment tank (1021) is equipped with a pH detector (1025).

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