A cathode current-carrying rod and method for an aluminum electrolytic cell

Abstract

The present invention relates to a cathode conductive rod for an aluminum electrolytic cell and a method for producing the same. The cathode conductive rod comprises a copper core, a grooved steel rod body, and a steel sealing plate. The grooved steel rod body has a groove in the middle, a stopper at the top, the copper core cast in the groove, and the steel sealing plate welded to the stopper. The copper core may have a uniform or variable cross-section. The present invention utilizes a casting method to produce the cathode conductive rod, significantly reducing machining costs, lowering investment, and further facilitating the promotion of copper-core steel rod embedding technology.

Description

Technical Field

[0001] The present invention belongs to the technical field of aluminum electrolysis equipment, and in particular relates to a cathode conductive rod for an aluminum electrolysis cell and a method thereof. Background Art

[0002] Electricity costs account for approximately 40% of total costs at domestic aluminum electrolysis plants. Energy conservation and consumption reduction are crucial for the aluminum electrolysis industry to enhance its market competitiveness. DC power consumption per ton of aluminum produced is directly proportional to the average cell voltage and inversely proportional to the current efficiency. Therefore, reducing voltage drop is a key approach to lowering DC power consumption per ton of aluminum. As aluminum electrolysis cells scale up, effectively reducing unit energy consumption is a crucial factor in achieving economic returns for aluminum electrolysis companies. Aluminum electrolysis companies have been committed to adjusting production processes and adopting new technologies such as low temperature and low voltage to achieve energy conservation and emission reductions.

[0003] There are generally two types of traditional cathode conductive rods in the aluminum electrolysis industry: one is made of a steel rod with low resistance, and the other is a copper rod embedded in a steel rod with low resistance. The first method uses a steel rod with low resistance, but the resistance is still relatively high compared to the steel rod embedded with copper rod. Although the second method embeds a copper rod in a steel rod, which significantly reduces the resistance of the cathode conductive rod and significantly reduces power consumption, the process steps of this method of embedding a copper core in a steel rod are: first, drilling a hole in the steel rod, which has very high requirements for the cylindricity, straightness, and smoothness of the drilled hole. Similarly, the cylindricity, straightness, and smoothness of the copper rod are also very high. As a result, these high-precision machining processes have very high processing costs, which limits the promotion of this technology. Summary of the Invention

[0004] In view of the shortcomings of the existing technology, the present invention provides a cathode conductive rod and method for aluminum electrolytic cells. The cathode conductive rod is manufactured by a casting molding method, which greatly reduces the machining cost, is conducive to reducing investment, and is more conducive to the promotion of embedded copper core steel rod technology.

[0005] A cathode conductive rod for an aluminum electrolytic cell comprises a copper core, a grooved steel rod body and a steel sealing plate. The grooved steel rod body has a groove in the middle and a stopper at the top of the groove. The copper core is cast in the groove and the steel sealing plate is welded in the stopper. The copper core has a uniform cross-section or a variable cross-section.

[0006] When the process has no requirements on current distribution, the copper core is a copper core with a uniform cross-section.

[0007] When the process has requirements for current distribution, the copper core is a variable-section copper core, and the upper surface of the groove and the lower surface of the copper core are both stepped or both the upper surface of the groove and the lower surface of the copper core have a slope.

[0008] The above-mentioned method for manufacturing a cathode conductive rod for an aluminum electrolysis cell comprises the following steps:

[0009] Step 1: Opening a groove on the steel rod to produce a steel rod with grooves;

[0010] Step 2: Before casting, preheat the steel rod with grooves to 750-850°C, and then pour molten copper into the grooves of the steel rod with grooves;

[0011] Step 3: Cool to 200-300℃ after casting;

[0012] Step 4: Weld the steel sealing plate to the outside of the groove, that is, to the stopper at the top of the groove, to protect the copper core.

[0013] The groove is formed by machining.

[0014] The groove is formed by milling.

[0015] The beneficial effects of the present invention are:

[0016] 1. The present invention adopts the method of directly casting molten copper to form a copper core to manufacture the cathode conductive rod, and the copper core is protected by welding a steel sealing plate. The entire processing process has no processing accuracy requirements, is easy to process, and has extremely low manufacturing cost.

[0017] 2. The cathode conductive rod for an aluminum electrolytic cell provided by the present invention is a copper-core steel rod, which can effectively reduce the voltage drop of the cathode group and effectively reduce the operating cost of the electrolytic cell.

[0018] 3. The grooves in the present invention are formed by mechanical processing and do not require high processing accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic structural diagram of a cathode conductive rod for an aluminum electrolysis cell provided in Example 1 of the present invention;

[0020] Figure 2 for Figure 1 AA view;

[0021] Figure 3 This is a schematic structural diagram of a cathode conductive rod for an aluminum electrolysis cell provided in Example 2 of the present invention;

[0022] Figure 4 for Figure 3 BB view;

[0023] Figure 5 for Figure 3 CC view;

[0024] Figure 6 for Figure 3 DD view;

[0025] Figure 7 This is a schematic structural diagram of a cathode conductive rod for an aluminum electrolysis cell provided in Example 3 of the present invention;

[0026] Figure 8 for Figure 7 EE view;

[0027] in,

[0028] 1-Steel sealing plate, 2-Copper core, 3-Steel rod with grooves. DETAILED DESCRIPTION

[0029] In order to better explain the present invention and facilitate understanding, the technical solutions and effects of the present invention are described in detail below with reference to the accompanying drawings through specific implementation methods.

[0030] Example 1

[0031] like Figure 1-2 As shown, a cathode conductive rod for an aluminum electrolytic cell is mounted on a cathode block and comprises a copper core 2, a grooved steel rod body 3, and a steel sealing plate 1. The grooved steel rod body 3 has a groove in the middle and a stopper at the top. The copper core 2 is cast in the groove, and the steel sealing plate 1 is welded into the stopper. In this embodiment, the process has no requirements for current distribution. The copper core 2 is a uniform cross-section copper core, meaning that the cross-sectional area of the copper core 2 along the longitudinal direction is constant and unchanged.

[0032] The method for manufacturing the cathode conductive rod for an aluminum electrolysis cell comprises the following steps:

[0033] Step 1: A groove is formed on the steel rod to produce a steel rod 3 with a groove. The groove is formed by mechanical processing, specifically milling. The groove has a uniform cross-section.

[0034] Step 2: Before casting, preheat the steel rod 3 with grooves. In this embodiment, when the temperature reaches 800° C., molten copper is cast into the grooves of the steel rod 3 with grooves.

[0035] Step 3: In this embodiment, the casting is cooled to 260°C;

[0036] Step 4: Weld the steel sealing plate 1 to the outside of the groove, that is, to the stopper at the top of the groove, to protect the copper core 2.

[0037] Example 2

[0038] like Figure 3-6As shown, a cathode conductive rod for an aluminum electrolytic cell is installed on a cathode block, comprising a copper core 2, a steel rod body 3 with a groove, and a steel sealing plate 1. The grooved steel rod body 3 has a groove in the middle, a stopper is provided at the top of the groove, the copper core 2 is cast in the groove, and the steel sealing plate 1 is welded in the stopper. In this embodiment, the process has requirements for current distribution, and it is necessary to limit the current distribution during aluminum electrolysis. Therefore, the cross-sectional sizes of the grooves are different, that is, the copper core 2 is a variable-section copper core, that is, the cross-sectional areas of the copper core 2 along the longitudinal direction are different. The larger the cross-sectional area of the copper core 2, the smaller the resistance, and the greater the current distribution required by the process; the upper surface of the groove and the lower surface of the copper core 2 are both stepped.

[0039] The method for manufacturing the cathode conductive rod for an aluminum electrolysis cell comprises the following steps:

[0040] Step 1: A groove is formed on the steel rod to produce a steel rod 3 with a groove. The groove is formed by mechanical processing, specifically milling. The upper surface of the groove is stepped.

[0041] Step 2: Before casting, preheat the grooved steel rod 3 to 750° C., and pour molten copper into the grooves of the grooved steel rod 3;

[0042] Step 3: Cool to 200°C after casting;

[0043] Step 4: Weld the steel sealing plate 1 to the outside of the groove, that is, to the stopper at the top of the groove, to protect the copper core 2.

[0044] Example 3

[0045] like Figure 7-8 As shown, a cathode conductive rod for an aluminum electrolytic cell is installed on a cathode block and includes a copper core 2, a steel rod body 3 with a groove, and a steel sealing plate 1. The grooved steel rod body 3 has a groove in the middle, a stopper is provided at the top of the groove, the copper core 2 is cast in the groove, and the steel sealing plate 1 is welded in the stopper. In this embodiment, the process has requirements for current distribution. The copper core 2 is a tapered variable-section copper core, that is, the cross-sectional area of the copper core 2 along the longitudinal direction is equal. The larger the cross-section of the copper core 2, the smaller the resistance, and the greater the current distribution required by the process; the upper surface of the groove and the lower surface of the copper core 2 are both inclined, and the angle between them and the horizontal plane is greater than 0°.

[0046] The method for manufacturing the cathode conductive rod for an aluminum electrolysis cell comprises the following steps:

[0047] Step 1: A groove is formed on the steel rod to produce a steel rod 3 with a groove. The groove is formed by mechanical processing, specifically by milling. The upper surface of the groove has an inclination.

[0048] Step 2: Before casting, preheat the steel rod 3 with grooves. When the temperature reaches 850°C, molten copper is cast into the grooves of the steel rod 3 with grooves.

[0049] Step 3: After casting, cool to 300℃;

[0050] Step 4: Weld the steel sealing plate 1 to the outside of the groove, that is, to the stopper at the top of the groove, to protect the copper core 2.

[0051] The step-type resistors provided in Example 2 and the slope-type resistors provided in Example 3 are essentially the same, both adjusting the resistance and current distribution by adjusting the cross-sectional size of the copper core. Therefore, when the process requires current distribution, either method can be selected.

Claims

1. A method for manufacturing a cathode conductive rod for an aluminum electrolysis cell, characterized in that: The cathode conductive rod used in the aluminum electrolytic cell includes a copper core, a steel rod body with a groove, and a steel sealing plate. The grooved steel rod body has a groove in the middle, a stopper is provided at the top of the groove, the copper core is cast in the groove, and the steel sealing plate is welded in the stopper. The copper core has a uniform cross-section or a variable cross-section. The following steps are involved: Step 1: Opening a groove on the steel rod to produce a steel rod with grooves; Step 2: Before casting, preheat the steel rod with grooves to 750-850°C, and then pour molten copper into the grooves of the steel rod with grooves; Step 3: Cool to 200~300℃ after casting; Step 4: Weld the steel sealing plate to the outside of the groove, that is, to the stopper at the top of the groove, to protect the copper core; When the process has requirements for current distribution, the copper core is a variable-section copper core, and the upper surface of the groove and the lower surface of the copper core are both stepped or both the upper surface of the groove and the lower surface of the copper core have a slope.

2. The method for manufacturing a cathode conductive rod for an aluminum electrolysis cell according to claim 1, characterized in that: When the process has no requirements on current distribution, the copper core is a copper core with a uniform cross-section.

3. The method for manufacturing a cathode conductive rod for an aluminum electrolysis cell according to claim 1, characterized in that: The groove is formed by machining.

4. The method for manufacturing a cathode conductive rod for an aluminum electrolysis cell according to claim 3, wherein: The groove is formed by milling.

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