An electrolyte temperature control method based on heat balance calculation
By employing thermal balance calculations and composite insulation structure design, combined with a forced air cooling system, the problem of inaccurate electrolyte temperature control in copper electrolytic refining was solved, achieving energy saving, consumption reduction, product quality improvement, and extended equipment lifespan.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- CHIFENG YUNTONG NON FERROUS METAL CO LTD
- Filing Date
- 2026-01-19
- Publication Date
- 2026-06-05
Smart Images
Figure CN122147459A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of copper electrolytic refining technology, specifically to a method for controlling electrolyte temperature based on thermal balance calculation. Background Technology
[0002] In the copper electrolytic refining process, electrolyte temperature is a core process parameter determining production efficiency and product quality. Its control precision directly affects current efficiency, electrolyte conductivity, and cathode crystal morphology. Specifically, for every 1°C increase in electrolyte temperature, its resistance decreases by approximately 0.7%, effectively reducing cell voltage and DC power consumption. It also alleviates copper ion depletion near the cathode, promoting uniform metal deposition. However, excessively high temperatures exacerbate electrolyte evaporation, leading to acid mist pollution and compromising electrolyte composition stability. Conversely, excessively low temperatures significantly increase electrolytic energy consumption and reduce production efficiency. Therefore, achieving precise and stable control of electrolyte temperature is a key technological requirement in the electrolytic refining process.
[0003] Traditional electrolyte temperature control methods mainly rely on operator experience or simple feedback control loops, using external steam heating or forced cooling water to maintain the temperature. However, this extensive control mode has significant drawbacks: on the one hand, the energy consumption of external heating and cooling systems is extremely high, especially in low-temperature winter environments, where disordered heat dissipation from the electrolytic cell and circulation pipelines leads to a surge in steam consumption, resulting in serious energy waste; on the other hand, manual intervention and simple feedback control have strong response lags, making it difficult to cope with dynamic disturbances such as fluctuations in electrolytic load and changes in ambient temperature, which can easily cause electrolyte temperature fluctuations to exceed ±2℃, failing to meet the requirements of high-precision production.
[0004] To overcome the precision bottleneck of traditional control methods, the industry has begun exploring temperature regulation technologies based on real-time monitoring data. For example, Chinese patent CN117344353B discloses an adaptive temperature distribution regulation system and method for electrolytic cells. This technical solution constructs a real-time monitoring network of the electrolyte temperature field by deploying temperature acquisition units, and achieves adaptive temperature regulation in conjunction with an analysis unit. Compared with the traditional manual control mode, its real-time temperature monitoring and degree of automation are significantly improved. However, this technology focuses primarily on temperature field monitoring and software-level analysis and adjustment, without constructing a refined heat balance calculation model for the entire electrolytic refining system. It cannot accurately quantify the heat input and output of each stage, including current-generated heat, liquid surface evaporation heat dissipation, tank radiation heat dissipation, and pipeline heat loss. This results in a lack of precise heat balance data to support the adjustment strategy, making it difficult to achieve accurate temperature control at its root. Secondly, this technology does not address the optimized design of the insulation structure for core hardware facilities such as the electrolytic cell and circulation pipelines. Industrial practice shows that traditional electrolytic cell insulation structures are crude, with radiative and convective heat loss from the tank and heat loss from circulation pipelines alone accounting for over 40% of the total system heat loss. If disordered heat loss cannot be reduced through hardware optimization, relying solely on software adjustment still requires significant external heating, failing to solve the energy waste problem. Finally, this technology does not propose a low-cost active cooling solution. In high-temperature environments or high-current-density production conditions during summer, the system's heat generation surges, and existing cooling methods alone are insufficient to quickly remove excess heat, easily leading to the risk of temperature runaway. Summary of the Invention
[0005] To address the problems existing in the prior art, the present invention provides an electrolyte temperature control method based on thermal balance calculation.
[0006] To achieve the above objectives, the technical solution of the present invention is as follows:
[0007] An electrolyte temperature control method based on thermal balance calculation includes the following steps:
[0008] (1) Heat balance parameter acquisition and calculation: Collect process parameters of each process and related equipment in the electrolytic refining system, and calculate the heat input and heat loss of the system based on the heat balance equation; the heat input includes the heat generated by the current passing through the electrolyte and cathode plate, the heat input of each process and the heat input of the evaporator; the heat loss includes heat dissipation by evaporation of the liquid surface of the electrolytic cell, heat dissipation by radiation and convection, heat loss of the circulating pipeline and heat loss of the crystallization tank;
[0009] (2) Optimization of the insulation structure of the electrolytic cell: Based on the heat balance calculation results, the electrolytic cell is insulated; needle-punched felt is used to fill the small gaps between the electrolytic cells, thin insulation boards are used to fill the larger gaps between the electrolytic cells, and the outer walls of the remaining electrolytic cells are covered with insulation material and fixed; the outer surface of the insulation material is coated with resin, covered with multiple layers of fiberglass cloth, and finally coated with resin topcoat; at the same time, PVC polypropylene acid-resistant tank cover cloth is used to cover the liquid surface of the electrolytic cell;
[0010] (3) Configuration of circulating tank air cooling system: A fiberglass pipe is installed near the main return liquid pipe in the electrolyte circulating tank. One end of the pipe extends to the outside and is connected to an axial flow fan. By adjusting the opening of the air inlet valve and the frequency of the acid mist settling tower fan, the heat of the return liquid is carried away by convection.
[0011] (4) Temperature dynamic control: Real-time monitoring of electrolyte inlet and return temperatures. When the temperature is higher than the preset range, the air volume of the axial flow fan is increased. When the ambient temperature is too low and the heat loss is too large, the resistance heat generated by the current passing through the electrolyte is used to supplement the heat. No additional steam heating is required, and the electrolyte temperature is kept stable at 65-69℃.
[0012] Further, the heat balance equation in step (1) is q=Qr・Cp△t, where q is the heat exchange, Q is the electrolyte circulation volume, r is the electrolyte density, Cp is the electrolyte specific heat capacity, and △t is the electrolyte temperature difference.
[0013] Furthermore, in step (2), the insulation material includes one or more of ceramic fiber felt, rock wool, and glass wool.
[0014] Furthermore, the diameter of the fiberglass pipe in step (3) is 400mm, the air volume of the axial flow fan is 18000 cubic meters / hour, and the air supply temperature is 25-30℃.
[0015] Furthermore, in step (4), the electrolyte inlet temperature is 65-66℃ and the return temperature is 67-69℃.
[0016] Compared with the prior art, the beneficial effects of the present invention are as follows:
[0017] 1. Significant energy saving and consumption reduction: Through thermal balance calculation and ultimate composite insulation structure design, this invention minimizes heat loss, ensuring that the resistance heat generated during electrolysis is sufficient to maintain the process temperature, thereby achieving "zero steam" input and significantly reducing production costs.
[0018] 2. Precise temperature control and fast response: By setting up a forced air cooling system at the return liquid main, combined with real-time monitoring and feedback, it can quickly and actively adjust the heat dissipation for overheating in summer or under high current density, solving the problem of low efficiency of traditional passive cooling.
[0019] 3. Extend equipment life: The composite insulation structure, which combines needle-punched felt filling with resin / fiberglass outer wall, not only improves insulation performance but also enhances the corrosion resistance of the electrolytic cell, effectively extending the service life of the equipment.
[0020] 4. Improve product quality: By strictly controlling the electrolyte temperature within the optimal range of 65℃-69℃, electrolysis efficiency and the crystallization quality of the cathode plate are guaranteed, and various process defects caused by temperature fluctuations are avoided. Attached Figure Description
[0021] The embodiments of the present invention will be further described below with reference to the accompanying drawings, wherein:
[0022] Figure 1 A process flow diagram of the present invention is shown. Detailed Implementation
[0023] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.
[0024] Reference Appendix Figure 1 An electrolyte temperature control method based on thermal balance calculation includes the following steps:
[0025] (1) Heat balance parameter acquisition and calculation: Collect process parameters of each process and related equipment in the electrolytic refining system, and calculate the heat input and heat loss of the system based on the heat balance equation; heat input includes the heat generated by the current passing through the electrolyte and cathode plate, the heat input of each process and the heat input of the evaporator; heat loss includes heat dissipation by evaporation of the liquid surface of the electrolytic cell, heat dissipation by radiation and convection, heat loss of the circulating pipeline and heat loss of the crystallization tank;
[0026] (2) Optimization of the insulation structure of the electrolytic cell: Based on the heat balance calculation results, the electrolytic cell is insulated; needle-punched felt is used to fill the small gaps between the electrolytic cells, thin insulation boards are used to fill the larger gaps between the electrolytic cells, and the outer walls of the remaining electrolytic cells are covered with insulation material and fixed; the outer surface of the insulation material is coated with resin, covered with multiple layers of fiberglass cloth, and finally coated with resin topcoat; at the same time, PVC polypropylene acid-resistant tank cover cloth is used to cover the liquid surface of the electrolytic cell;
[0027] (3) Configuration of circulating tank air cooling system: A fiberglass pipe is installed near the main return liquid pipe in the electrolyte circulating tank. One end of the pipe extends to the outside and is connected to an axial flow fan. By adjusting the opening of the air inlet valve and the frequency of the acid mist settling tower fan, the heat of the return liquid is carried away by convection.
[0028] (4) Temperature dynamic control: Real-time monitoring of electrolyte inlet and return temperatures. When the temperature is higher than the preset range, the air volume of the axial flow fan is increased. When the ambient temperature is too low and the heat loss is too large, the resistance heat generated by the current passing through the electrolyte is used to supplement the heat. No additional steam heating is required, and the electrolyte temperature is kept stable at 65-69℃.
[0029] In one embodiment of the present invention, the heat balance equation in step (1) is q=Qr・Cp△t, where q is the heat exchange, Q is the electrolyte circulation volume, r is the electrolyte density, Cp is the electrolyte specific heat capacity, and △t is the electrolyte temperature difference.
[0030] In one embodiment of the present invention, in step (2), the thermal insulation material includes one or more of ceramic fiber felt, rock wool, and glass wool.
[0031] In one embodiment of the present invention, in step (3), the diameter of the fiberglass pipe is 400mm, the air volume of the axial flow fan is 18000 cubic meters / hour, and the air supply temperature is 25-30℃.
[0032] In one embodiment of the present invention, the electrolyte inlet temperature in step (4) is 65-66°C and the return temperature is 67-69°C.
[0033] Example 1
[0034] (1) Acquisition and calculation of thermal balance parameters
[0035] A copper electrolytic refining system was selected as the application object. The process parameters of the electrolysis process, circulation process and related equipment such as evaporator and crystallizer of the system were collected. The heat input and heat loss of the system were calculated based on the heat balance equation q=Qr·Cp△t. The electrolyte circulation volume Q was taken as the endpoint value within the design range, and the electrolyte density r and specific heat capacity Cp were the measured values of the electrolyte used in the system.
[0036] Heat input mainly includes: Joule heat generated by current passing through the electrolyte and cathode plate, heat input from heating devices in each process, and rated heat input from the evaporator; heat loss mainly includes: heat dissipation from evaporation of the electrolyte surface, heat dissipation from radiation and convection between the tank and the environment, heat loss along the circulation pipeline, and heat loss during the cooling process of the crystallization tank. All sub-items of loss are obtained through a combination of actual measurement and calculation.
[0037] (2) Optimization of the insulation structure of the electrolytic cell
[0038] Based on the above heat balance calculation results, the distribution of gaps in the electrolytic cells and the key areas of heat loss were determined, and the insulation structure was optimized. For smaller gaps with a width ≤ 5mm between electrolytic cells, ceramic fiber felt was used for filling; for larger gaps with a width > 5mm, thin insulation boards with a thickness of 50mm were used for filling; the outer walls of the remaining electrolytic cells were covered with ceramic fiber felt and fixed with stainless steel anchors.
[0039] The surface treatment of the insulation material is carried out according to the following process: First, apply one coat of epoxy resin primer evenly, with a thickness of about 50μm; then cover with three layers of fiberglass cloth, with epoxy resin applied between each layer for bonding; finally, apply one coat of epoxy resin topcoat, with a thickness of about 80μm. At the same time, use PVC polypropylene acid-resistant tank cover cloth to completely cover the surface of the electrolytic cell, ensuring that there are no exposed areas.
[0040] (3) Configuration of circulating tank air-cooling system
[0041] A 400mm diameter fiberglass pipe is installed near the main return pipe in the electrolyte circulation tank. One end of the pipe extends outdoors and connects to an axial flow fan with a capacity of 18,000 cubic meters per hour. A manual air inlet valve is installed in the indoor section of the pipe, while the outdoor section connects to the acid mist settling tower. The frequency of the settling tower fan can be adjusted using a frequency converter. By adjusting the full opening of the air inlet valve and the maximum frequency of the acid mist settling tower fan, air convection is used to enhance the heat removal effect of the returned liquid.
[0042] (4) Dynamic temperature control
[0043] Temperature sensors are installed at the inlet and outlet of the circulation tank to monitor the electrolyte inlet and outlet temperatures in real time. The temperature control range is set at 65-69℃, with the inlet temperature controlled at 65℃ and the outlet temperature at 69℃. When the outlet temperature is ≥69℃, the axial flow fan operates at maximum airflow, with the airflow temperature controlled at 25℃. When the ambient temperature is below 5℃, resulting in excessive heat loss, and the inlet temperature is ≤65℃, the electrolytic current density is increased to utilize the resistance heat generated by the current passing through the electrolyte to supplement the heat, eliminating the need to activate an additional steam heating device, ultimately maintaining the electrolyte temperature stably within the 65-69℃ range.
[0044] Example 2
[0045] (1) Acquisition and calculation of thermal balance parameters
[0046] A copper electrolytic refining system was selected as the application object. Process parameters of each process in the system and operating parameters of related equipment were collected. The thermal balance state of the system was calculated based on the heat balance equation q=Qr·Cp△t. The electrolyte circulation volume Q was taken as the other end value within the design range. The electrolyte density r and specific heat capacity Cp were adopted as the standard values of the electrolyte of the system. The temperature difference △t was obtained by measuring the temperature difference between the inlet and outlet.
[0047] Heat income accounting includes: heat generated by current passing through the electrolyte and cathode plate, process heat income of each step, and actual heat income of the evaporator; heat loss accounting includes: heat dissipation from evaporation of the electrolyte surface, heat dissipation from radiation and convection of the tank, heat loss before insulation of the circulating pipeline, and heat loss during solid-liquid separation in the crystallization tank. All parameters are determined by a combination of on-site testing and theoretical calculation.
[0048] (2) Optimization of the insulation structure of the electrolytic cell
[0049] Based on the heat loss distribution data of the electrolytic cell obtained from heat balance calculations, the insulation structure was modified. Smaller gaps between electrolytic cells (width ≤ 5mm) were filled with glass wool; larger gaps (width > 5mm) were filled with thin insulation boards with a thickness of 30mm; the outer wall of the electrolytic cell was fully covered with a glass wool insulation layer and fixed with carbon steel anchors.
[0050] The outer surface protection process for the insulation layer is as follows: First, apply one coat of phenolic resin primer, approximately 40μm thick; then cover with two layers of fiberglass cloth, with phenolic resin applied between the layers for bonding; finally, apply one coat of phenolic resin topcoat, approximately 60μm thick. The electrolytic cell surface is fully covered with a PVC polypropylene acid-resistant tank cover, with an overlap width of ≥100mm to ensure a tight seal.
[0051] (3) Configuration of circulating tank air-cooling system
[0052] A 400mm diameter fiberglass pipe is installed at the main return pipe interface of the electrolyte circulation tank. The outdoor end of the pipe is connected to an axial flow fan with a flow rate of 18,000 cubic meters per hour, and the indoor end is equipped with an electric air inlet valve. The pipe is connected in series with the acid mist settling tower and then exposed to the outdoor atmosphere. By adjusting the opening of the air inlet valve and the frequency of the acid mist settling tower fan, the return liquid is cooled by convection of ambient temperature air, and the supply air temperature is controlled at 30℃.
[0053] (4) Dynamic temperature control
[0054] Temperature transmitters are installed on both the electrolyte inlet and return pipelines to transmit temperature signals to the control system in real time. The upper limit for the inlet temperature is set at 66℃, and the lower limit for the return temperature is set at 67℃, with the system's target temperature range maintained between 65-69℃. When the return temperature is ≥69℃, the axial flow fan operates at full load to maximize airflow. When the ambient temperature is too low in winter, and the inlet temperature is ≤65℃, the electrolysis process current is adjusted to utilize the resistance heating of the electrolyte to supplement heat, eliminating the need for additional steam heating. This stabilizes the electrolyte inlet temperature at 65℃ and the return temperature at 69℃, meeting process requirements.
[0055] The beneficial effects of this invention are as follows:
[0056] 1. Significant energy saving and consumption reduction: Through thermal balance calculation and ultimate composite insulation structure design, this invention minimizes heat loss, ensuring that the resistance heat generated during electrolysis is sufficient to maintain the process temperature, thereby achieving "zero steam" input and significantly reducing production costs.
[0057] 2. Precise temperature control and fast response: By setting up a forced air cooling system at the return liquid main, combined with real-time monitoring and feedback, it can quickly and actively adjust the heat dissipation for overheating in summer or under high current density, solving the problem of low efficiency of traditional passive cooling.
[0058] 3. Extend equipment life: The composite insulation structure, which combines needle-punched felt filling with resin / fiberglass outer wall, not only improves insulation performance but also enhances the corrosion resistance of the electrolytic cell, effectively extending the service life of the equipment.
[0059] 4. Improve product quality: By strictly controlling the electrolyte temperature within the optimal range of 65℃-69℃, electrolysis efficiency and the crystallization quality of the cathode plate are guaranteed, and various process defects caused by temperature fluctuations are avoided.
[0060] The foregoing descriptions have outlined some exemplary embodiments of the present invention. It is understood that these embodiments are merely illustrative and do not constitute a limitation on the scope of protection of the present invention. Features in these embodiments can be rearranged in suitable ways, and the resulting solutions remain within the scope of protection claimed by the present invention. All other embodiments obtained by those skilled in the art based on the foregoing embodiments without inventive effort, i.e., all modifications, equivalent substitutions, and improvements made within the spirit and principles of this application, fall within the scope of protection claimed by the present invention.
Claims
1. A method for controlling electrolyte temperature based on thermal balance calculation, characterized in that, Includes the following steps: (1) Heat balance parameter acquisition and calculation: Collect process parameters of each process and related equipment in the electrolytic refining system, and calculate the heat input and heat loss of the system based on the heat balance equation; the heat input includes the heat generated by the current passing through the electrolyte and cathode plate, the heat input of each process and the heat input of the evaporator; the heat loss includes heat dissipation by evaporation of the liquid surface of the electrolytic cell, heat dissipation by radiation and convection, heat loss of the circulating pipeline and heat loss of the crystallization tank; (2) Optimization of the insulation structure of the electrolytic cell: Based on the heat balance calculation results, the electrolytic cell is insulated; needle-punched felt is used to fill the small gaps between the electrolytic cells, thin insulation boards are used to fill the larger gaps between the electrolytic cells, and the outer walls of the remaining electrolytic cells are covered with insulation material and fixed; the outer surface of the insulation material is coated with resin, covered with multiple layers of fiberglass cloth, and finally coated with resin topcoat; at the same time, PVC polypropylene acid-resistant tank cover cloth is used to cover the liquid surface of the electrolytic cell; (3) Configuration of circulating tank air cooling system: A fiberglass pipe is installed near the main return liquid pipe in the electrolyte circulating tank. One end of the pipe extends to the outside and is connected to an axial flow fan. By adjusting the opening of the air inlet valve and the frequency of the acid mist settling tower fan, the heat of the return liquid is carried away by convection. (4) Temperature dynamic control: Real-time monitoring of electrolyte inlet and return temperatures. When the temperature is higher than the preset range, the air volume of the axial flow fan is increased. When the ambient temperature is too low and the heat loss is too large, the resistance heat generated by the current passing through the electrolyte is used to supplement the heat. No additional steam heating is required, and the electrolyte temperature is kept stable at 65-69℃.
2. The electrolyte temperature control method based on thermal balance calculation according to claim 1, characterized in that, The heat balance equation in step (1) is q=Qr・Cp△t, where q is the heat exchange, Q is the electrolyte circulation volume, r is the electrolyte density, Cp is the electrolyte specific heat capacity, and △t is the electrolyte temperature difference.
3. The electrolyte temperature control method based on thermal balance calculation according to claim 1, characterized in that, In step (2), the insulation material includes one or more of ceramic fiber felt, rock wool, and glass wool.
4. The electrolyte temperature control method based on thermal balance calculation according to claim 1, characterized in that, The diameter of the fiberglass pipe in step (3) is 400mm, the air volume of the axial flow fan is 18000 cubic meters / hour, and the air supply temperature is 25-30℃.
5. The electrolyte temperature control method based on thermal balance calculation according to claim 1, characterized in that, In step (4), the electrolyte inlet temperature is 65-66℃ and the return temperature is 67-69℃.