A new type of pre-nickel removal liquid pre-cooling device

Abstract

The utility model discloses a novel nickel removal front liquid precooling device relates to copper smelting electrolysis technical field, adopts the gradient heat exchange scheme of circulating water primary cooling and nickel removal rear liquid secondary cooling, and this device is by primary heat exchange unit, secondary heat exchange unit, nickel removal rear liquid jar, refrigeration agitator jar, nickel removal plate frame and temperature monitoring and control unit composition, utilize existing main circulating water as primary cold source, and the nickel removal rear liquid of 62 65 DEG C is precooled to 35 40 DEG C, and then nickel removal rear liquid of -10 DEG C 0 DEG C is secondary cold source, is stored through nickel removal rear liquid jar and circulates, and liquid is further reduced to 10 15 DEG C, and finally after the terminal cooling of refrigeration agitator jar is sent into nickel removal plate frame production nickel sulfate to 15 DEG C. After adopting this device, the refrigeration unit power consumption reduces, and single jar processing time shortens, and daily processing capacity promotes, and electrolyte nickel concentration is stable, and cathode copper nickel impurity drops, has the advantages such as energy -conserving and loss -reducing, yield increasing and quality improving, investment saving, and small amount of reconstruction.

Description

Technical Field

[0001] This utility model relates to the field of copper smelting electrolysis technology, and more specifically to a novel pre-cooling device for nickel removal liquid. Background Technology

[0002] During copper electrolytic refining, the concentration of nickel ions in the electrolyte continuously accumulates and needs to be removed through a purification system. A typical process uses a brine chiller to cool the final copper removal solution to -15°C before feeding it into a nickel removal plate and frame to produce nickel sulfate.

[0003] The existing technology has the following technical problems: (1) Excessive cooling load: The temperature of the pre-nickel removal liquid (final copper removal liquid) is as high as 62-65℃, and the clean liquid system needs to cool it to -15℃, with a temperature difference of 77℃, resulting in huge energy consumption of the refrigeration unit. (2) Energy waste: The temperature of the post-nickel removal liquid is about -10℃ to 0℃, containing a large amount of cold energy. Direct return to the main system or discharge will cause cold energy loss and fail to achieve energy recovery. (3) Long cooling cycle: The cooling time of a single tank exceeds 8 hours, which leads to limited capacity of the nickel removal process. Moreover, the intermittent operation causes fluctuations in electrolyte composition, affecting the quality of cathode copper products. (4) High equipment load: The refrigeration unit operates at high load for a long time, resulting in an increased failure rate and increased maintenance costs. Utility Model Content

[0004] The purpose of this utility model is to provide a novel pre-cooling device for nickel stripping liquid in order to solve the above-mentioned technical problems.

[0005] To achieve the above objectives, this utility model specifically adopts the following technical solution:

[0006] A novel pre-cooling device for nickel stripping solution, used in the copper electrolyte purification process, includes:

[0007] The primary heat exchange unit includes a first plate heat exchanger, wherein the inlet of the coolant channel of the first plate heat exchanger is connected to the copper removal final liquid tank, and the inlet of the cooling medium channel is connected to the main circulating water pipe.

[0008] The secondary heat exchange unit includes a second plate heat exchanger, wherein the inlet of the coolant channel of the second plate heat exchanger is connected to the outlet of the coolant channel of the first plate heat exchanger, and the inlet of the cooling medium channel is connected to the denickelized liquid tank.

[0009] The denickel-removed liquid tank is used to store the low-temperature denickel-removed liquid after the denickel removal process and serves as a secondary cold source carrier.

[0010] The refrigerated mixing tank has its liquid inlet connected to the outlet of the denickelized liquid tank. The refrigerated mixing tank is used to receive the liquid cooled by the secondary heat exchange unit.

[0011] The nickel stripping plate frame has its liquid inlet connected to the outlet of the refrigerated mixing tank. The nickel stripping plate frame is used to receive the liquid after further cooling from the refrigerated mixing tank.

[0012] Preferably, a temperature monitoring and control unit is installed on the connecting pipeline between the first plate heat exchanger and the second plate heat exchanger.

[0013] Preferably, a cryogenic circulating pump is installed on the connecting pipeline between the nickel-de-nickel tank and the second plate heat exchanger.

[0014] The copper electrolyte purification method employs a novel pre-cooling device for the nickel removal solution, and includes the following steps:

[0015] 1. The copper stripping final solution at 62-65℃ is drawn out from the copper stripping final solution tank and first undergoes primary heat exchange with the circulating cooling water provided by the main circulating water pipe in the first plate heat exchanger, and the temperature drops to 35-40℃.

[0016] 2. The liquid after primary cooling is then subjected to secondary heat exchange with the nickel-de-nickel liquid at -10℃ to 0℃ in the second plate heat exchanger, where the temperature drops to 10-15℃.

[0017] 3. The liquid after secondary cooling is sent to a refrigerated mixing tank, and after final cooling to -15°C by a refrigeration unit, it enters the nickel stripping plate and frame to produce nickel sulfate;

[0018] 4. The nickel-removed liquid is stored as a secondary cold source in the nickel-removed liquid tank and returned to the main electrolyte system after the cold energy is recovered.

[0019] The beneficial effects of this utility model are as follows: It adopts a gradient heat exchange scheme of primary cooling with circulating water and secondary cooling with nickel stripping liquid. By using the existing main circulating water as the primary cold source, the copper stripping final liquid at 62-65℃ is pre-cooled to 35-40℃. Then, the nickel stripping liquid at -10℃ to 0℃ is used as the secondary cold source. The liquid is stored and circulated in the nickel stripping liquid tank, which further cools the liquid to 10-15℃. Finally, it is cooled to -15℃ in the freezing and stirring tank and then sent to the nickel stripping plate frame to produce nickel sulfate. Ultimately, it achieves the effects of reducing the power consumption of the refrigeration unit, shortening the processing time of a single tank, increasing the daily processing capacity, stabilizing the nickel concentration of the electrolyte, and reducing the copper and nickel impurities in the cathode. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the two-stage nickel removal precooling pipeline structure of this utility model;

[0021] Figure 2 This is a process flow diagram of the two-stage nickel stripping precooling system of this utility model.

[0022] Attached reference numerals: 1. Main circulating water pipe; 2. Copper removal final liquid tank; 3. Plate heat exchanger one; 4. Plate heat exchanger two; 5. Refrigerated mixing tank; 6. Nickel removal plate frame; 7. Nickel removal post-liquid tank. Detailed Implementation

[0023] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. The illustrative embodiments and descriptions of the present invention are used to explain the present invention, but are not intended to limit the present invention.

[0024] Example 1: Basic System Configuration

[0025] A copper smelter's clean electrolyte system has a total electrolyte volume of 7500 m³, with a designed processing capacity of 50 m³ / h. The novel pre-cooling device for the nickel stripping pre-liquid in this embodiment is configured as follows:

[0026] First plate heat exchanger 3: heat exchange area 80m², plate material is 316L stainless steel, designed temperature drop of 25℃, cooling the copper removal liquid from 62℃ to 37℃.

[0027] Second plate heat exchanger 4: heat exchange area 60m², plate material is 316L stainless steel, designed temperature drop of 20℃, cools the liquid after primary cooling from 37℃ to 12℃.

[0028] Nickel stripping liquid tank 7: The original storage tank is modified, with an effective volume of 200m³. The tank is equipped with a 0.5kW paddle agitator and the outer wall of the tank is covered with a 100mm thick rock wool insulation layer to ensure that the temperature of the nickel stripping liquid inside the tank is maintained between -10℃ and 0℃.

[0029] Cryogenic circulating pump 10: flow rate 60m³ / h, head 25m, motor power 7.5kW, provides a stable cold source circulation for secondary heat exchange;

[0030] Temperature monitoring and control unit: A PT100 temperature sensor 8 and an electric regulating valve group 9 are installed between the two-stage heat exchangers, with a control accuracy of ±1℃.

[0031] Operating Procedure: In the copper smelting electrolysis technology, the 62℃ copper removal final liquid is drawn from the copper removal final liquid tank 2 and first enters the first plate heat exchanger 3 to exchange heat with the circulating cooling water provided by the main circulating water pipe 1, reducing the temperature to 37℃. Then, it enters the second plate heat exchanger 4 to exchange heat with the -5℃ nickel removal liquid from the nickel removal liquid tank 7, further reducing the temperature to 12℃. The pre-cooled liquid enters the refrigerated stirring tank 5, where it is finally cooled to -15℃ by the brine refrigeration unit, and finally sent to the nickel removal plate frame 6 to produce nickel sulfate. After the secondary heat exchange, the temperature of the nickel removal liquid rises to approximately 15℃ and is returned to the main electrolyte system for reuse.

[0032] Implementation Results: After adopting this device for copper smelting electrolysis technology, the average daily power consumption of the refrigeration unit decreased from 4800 kWh to 3000 kWh, a reduction of 37.5%; the single tank processing time was shortened from 8 hours to 4 hours, and the daily processing capacity was increased by 100%; the nickel content of the electrolyte was stably controlled at 12 g / L, and the copper and nickel impurities in the cathode decreased to 3 ppm.

[0033] Example 2: Optimization system with automatic control function

[0034] Based on Example 1, this example adds an intelligent control system. The temperature monitoring and control unit uses a PLC controller, which monitors the temperature of the liquid after primary cooling in real time via intermediate liquid temperature sensor 8. When the temperature exceeds 40°C, the opening of the flow regulating valve group 9 is automatically increased to increase the cooling water flow; when the temperature is below 35°C, the valve opening is reduced to conserve water. A level transmitter is installed in the nickel-free liquid tank 7, which automatically alarms and replenishes the cooling source when the liquid level falls below 30%. Pressure transmitters are installed at the inlet and outlet of the two-stage heat exchangers to monitor pressure difference changes to determine scaling conditions and prompt cleaning and maintenance.

[0035] Example 3: Dual-mode operation configuration

[0036] In this embodiment, the first plate heat exchanger 3 and the second plate heat exchanger 4 adopt a switchable parallel / series connection structure. In winter and spring, when the temperature of the denickelized liquid is below -5°C, the system uses a series connection, with the liquid undergoing deep pre-cooling through the two heat exchangers sequentially. In summer and autumn, when the temperature of the denickelized liquid is close to 0°C, the system can switch to a parallel connection to increase the heat exchange area and flow rate while maintaining a constant throughput. The switching is achieved through a valve assembly, making operation simple and adaptable to different seasonal production needs.

[0037] The working principle of this utility model:

[0038] This device, based on the principle of energy cascade utilization, decomposes the cooling process of the high-temperature copper stripping final liquid into two stages: the first stage uses circulating cooling water, a low-cost cold source, to bear the basic load, reducing the liquid temperature to near ambient temperature; the second stage innovatively utilizes the low-grade cold energy of the nickel stripping liquid for deep pre-cooling, significantly reducing the burden on the refrigeration unit. The nickel stripping liquid tank, acting as a cold energy storage and buffer, resolves the supply and demand contradiction between the intermittent production of the nickel stripping liquid and continuous pre-cooling. Through the series combination of two-stage heat exchangers, rational cascade utilization of cold energy is achieved, enabling the recovery and reuse of more than 85% of the originally wasted cold energy.

[0039] The technical solutions provided by the embodiments of this utility model have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of the embodiments of this utility model. The description of the above embodiments is only for helping to understand the principles of the embodiments of this utility model. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the embodiments of this utility model. Therefore, the content of this specification should not be construed as a limitation of this utility model.

Claims

1. A novel pre-cooling device for nickel stripping solution, used in the copper electrolyte purification process, characterized in that, include: The primary heat exchange unit includes a first plate heat exchanger (3), the inlet of the coolant channel of the first plate heat exchanger (3) is connected to the copper removal final liquid tank (2), and the inlet of the cooling medium channel is connected to the main circulating water pipe (1). The secondary heat exchange unit includes a second plate heat exchanger (4), the inlet of the coolant channel of the second plate heat exchanger (4) is connected to the outlet of the coolant channel of the first plate heat exchanger (3), and the inlet of the cooling medium channel is connected to the denickelized liquid tank (7). The denickel-removed liquid tank (7) is used to store the low-temperature denickel-removed liquid after the denickel removal process and to serve as a secondary cold source carrier; The liquid inlet of the freezing stirring tank (5) is connected to the outlet of the denickelized liquid tank (7). The freezing stirring tank (5) is used to receive the liquid cooled by the secondary heat exchange unit. The nickel stripping plate frame (6) has a liquid inlet connected to the outlet of the refrigerated mixing tank (5). The nickel stripping plate frame (6) is used to receive the liquid after further cooling from the refrigerated mixing tank (5).

2. The novel pre-cooling device for nickel stripping liquid according to claim 1, characterized in that: A temperature monitoring and control unit is installed on the connecting pipe between the first plate heat exchanger (3) and the second plate heat exchanger (4).

3. The novel pre-cooling device for nickel stripping liquid according to claim 1, characterized in that: A cryogenic circulating pump is installed on the connecting pipeline between the nickel-de-nickel liquid tank (7) and the second plate heat exchanger (4).

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