Method for forcibly changing direction of current in aluminum electrolysis cell

Abstract

The invention discloses a method for forcibly changing the direction of current in an aluminum electrolysis cell, which is based on the characteristic that the current tends to the minimum resistance path, and by adjusting the structure of a conductive steel bar and the assembling and insulating mode of the conductive steel bar and a cathode carbon block, the current flowing line of the existing electrolysis cell in the aluminum liquid according to the horizontal line is changed. The current autonomously and vertically enters the cathode carbon block group from the molten aluminum and then is gathered to be discharged, so that the harm caused by the horizontal current is avoided; the structure of the conductive steel bar and the assembling and insulating modes of the conductive steel bar and the cathode carbon block are adjusted; the technical problem that the horizontal current is too large in the aluminum electrolysis production process can be fundamentally solved, and accidents are reduced.

Description

Technical Field

[0001] The present invention relates to a method for forcibly changing the current flow direction in an aluminum electrolysis cell, belonging to the technical field of electrolysis cell tools. Background Art

[0002] During the aluminum electrolysis process, due to the existence of horizontal current, under the action of the magnetic field, the aluminum liquid surface is affected by magnetic force and fluctuates. When the fluctuation is large, the anode and cathode will be connected by the aluminum liquid and short-circuited, causing the cell voltage to fluctuate. In severe cases, a "rolling aluminum" accident will occur. Therefore, it is necessary to avoid the probability of accidents and improve the operation stability of the electrolysis cell. In the conventional design, means such as increasing the pole pitch are used to maintain the operation stability of the electrolysis cell, at the cost of high voltage and high power consumption. Therefore, it is necessary to explore a technical solution that can effectively reduce the horizontal current in the aluminum electrolysis cell to completely solve this contradictory problem. There have been many previous studies on reducing the horizontal current in the electrolysis cell, such as: opening slits at the ends of the cathode steel bars, coating silicon carbide powder at the ends of the cathode steel bars, developing low-resistance and high-conductivity steel bars, etc. However, due to the failure to solve the essential current flow direction problem, the results have been very limited.

[0003] That is, there is a need for a method for forcibly changing the current flow direction in an aluminum electrolysis cell, which can fundamentally solve the technical problem of excessive horizontal current in the aluminum electrolysis production process and reduce the occurrence of accidents. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide a method for forcibly changing the current flow direction in an aluminum electrolysis cell, which can fundamentally solve the technical problem of excessive horizontal current in the aluminum electrolysis production process and reduce the occurrence of accidents; it can overcome the deficiencies of the prior art.

[0005] The purpose of the present invention is achieved by the following technical solutions: The present invention discloses a method for forcibly changing the current flow direction in an aluminum electrolysis cell. Based on the characteristic that current tends to flow along the path of the minimum resistance, by adjusting the structure of the conductive steel bar and the assembly and insulation method with the cathode carbon block, the existing electrolysis cell current flow path in the aluminum liquid along the horizontal line is changed, so that the current autonomously enters the cathode carbon block group vertically from the aluminum liquid and then aggregates to output electricity, avoiding the harm caused by the horizontal current; the adjustment of the structure of the conductive steel bar and the assembly and insulation method with the cathode carbon block includes: horizontally arranging a diversion steel bar and an electricity-output aggregating steel bar in parallel in the cathode carbon block group to form a composite conductive network, performing a full-surface insulation coating treatment on the electricity-output aggregating steel bar, and at the same time filling a high-impedance insulation casting layer at the contact interface between it and the cathode carbon block. By calculation, the resistance ratio of the horizontal / vertical path ≥ 10 3 to ensure that the vertical path forms an absolute conductive advantage.

[0006] As described above, the current flow in the electrolytic cell is as follows: The current flows from the anode rod → vertically enters and passes through the anode → vertically enters and passes through the molten electrolyte → vertically enters and passes through the aluminum liquid → vertically enters the cathode → vertically enters the horizontal current-carrying steel bar → enters the collecting current-carrying steel bar → enters the bus bar.

[0007] As described above, the structure for eliminating the horizontal current in the aluminum electrolytic cell includes the electrolytic cell body, on which an anode and a cathode carbon block are provided. Inside the cathode carbon block directly below the anode, a horizontal current-carrying steel bar is provided. In the middle of the horizontal current-carrying steel bar, a collecting current-carrying steel bar is connected. The outside of the collecting current-carrying steel bar is wrapped with an insulating material layer, and the end of the collecting current-carrying steel bar is connected to the bus bar.

[0008] As described above, the length and width of the horizontal current-carrying steel bar are not less than those of the lower bottom surface of the anode.

[0009] As described above, the horizontal current-carrying steel bar is fixedly welded to the collecting current-carrying steel bar or the horizontal current-carrying steel bar and the collecting current-carrying steel bar are integrally cast.

[0010] As described above, the collecting current-carrying steel bar is composed of a vertical section and a horizontal section connected to the horizontal current-carrying steel bar.

[0011] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. By changing the current output mode of the cathode carbon block, the present invention forces the current to output from the middle part of the horizontal current-carrying steel bar in the cathode carbon block group, that is, from the end output to the middle output. Then, the current is uniformly output in the direction of the collecting current-carrying steel bar and the bus bar, fundamentally blocking the conditions for generating horizontal current on the aluminum liquid surface, thereby eliminating the horizontal current generated on the aluminum liquid surface during the aluminum electrolysis process, greatly reducing the probability of accidents during the electrolysis process, further improving the stability of the electrolytic cell operation. The current flow direction is shown by the arrow direction in the figure.

[0012] 2. At the same time, due to the insulating material layer between the collecting current-carrying steel bar and the cathode carbon block, and the insulating material layer is composed of insulating casting material, the conditions for the current to take a short-circuit path in the aluminum liquid surface are essentially cut off, forcing the current to only pass through the electrolyte and aluminum liquid from the anode along the vertical shortest path and enter the cathode steel bar for collection and output. The current flow direction is: The current flows from the anode rod → vertically enters and passes through the anode → vertically enters and passes through the molten electrolyte → vertically enters and passes through the aluminum liquid → vertically enters the cathode → vertically enters the horizontal current-carrying steel bar → enters the collecting current-carrying steel bar → enters the bus bar. Thus, the possibility of generating horizontal current in the aluminum liquid is completely eliminated, greatly improving the stability of the aluminum liquid surface during the production process. At the same time, due to the stable aluminum liquid surface, the pole pitch, that is, the distance from the bottom of the anode to the aluminum liquid surface, can be significantly shortened during the production process, reducing the voltage of the electrolytic cell and greatly reducing the power consumption per ton of aluminum, bringing a technical revolution to the production of electrolytic aluminum.

[0013] 3. The length and width of the horizontal diversion steel bar are not less than those of the lower bottom surface of the anode. Such dimensions facilitate the vertical entry of current into the horizontal diversion steel bar.

[0014] Other advantages, objectives, and features of the present invention will be described to some extent in the subsequent specification, and to some extent, will be obvious to those skilled in the art based on the study of the following text, or can be taught from the practice of the present invention. The objectives and other advantages of the present invention can be achieved and obtained through the following specification. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the drawings, where: Figure 1 is a schematic diagram of the connection structure of the present invention.

[0016] Figure 2 is a schematic diagram of the theoretical current flow direction of the prior art.

[0017] Figure 3 is a schematic diagram of the current flow direction during the use of the prior art.

[0018] Among them, the electrolytic cell body 1; the anode 2; the cathode carbon block 3; the horizontal diversion steel bar 4; the aggregated outgoing steel bar 5; the insulating material layer 6; the bus bar 7. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0019] The following will refer to the drawings to describe the preferred embodiments of the present invention in detail. It should be understood that the preferred embodiments are only for illustrating the present invention and not for limiting the protection scope of the present invention.

[0020] As Figure 1 shown, a method for forcibly changing the current flow direction in an aluminum electrolytic cell disclosed by the present invention is based on the characteristic that current tends to flow along the path of the minimum resistance. By adjusting the structure of the conductive steel bar and the assembly and insulation method with the cathode carbon block, the existing electrolytic cell current flow path in the aluminum liquid along the horizontal line is changed, so that the current autonomously enters the cathode carbon block group vertically and then aggregates and outputs electricity, avoiding the harm caused by the horizontal current; the adjustment of the conductive steel bar structure and the assembly and insulation method with the cathode carbon block includes: arranging the horizontal diversion steel bar 4 and the aggregated outgoing steel bar 5 in parallel in the cathode carbon block group to form a composite conductive network, performing a full-surface insulation coating treatment on the aggregated outgoing steel bar 5, and at the same time filling a high-impedance insulation casting material layer at the contact interface with the cathode carbon block. By calculation, the resistance ratio of the horizontal / vertical path is ≥10 3, ensure that the vertical path forms an absolute conductive advantage. The direction of the current in the electrolytic cell is as follows: the current flows from the anode rod → vertically enters and passes through the anode 2 → vertically enters and passes through the molten electrolyte → vertically enters and passes through the aluminum liquid → vertically enters the cathode → vertically enters the horizontal diversion steel bar 4 → enters the aggregated power output steel bar 5 → enters the bus bar 7.

[0021] The structure for eliminating the horizontal current in the aluminum electrolytic cell includes the electrolytic cell body 1, on which an anode 2 and a cathode carbon block 3 are provided. Inside the cathode carbon block 3 directly below the anode 2, a horizontal diversion steel bar 4 is provided. In the middle of the horizontal diversion steel bar 4, an aggregated power output steel bar 5 is connected. The aggregated power output steel bar 5 is wrapped with an insulating material layer 6. The end of the aggregated power output steel bar 5 is connected to the bus bar 7. With such a structure, by changing the power output mode of the cathode carbon block, the current is forced to output from the middle part of the horizontal diversion steel bar 4 in the cathode carbon block group, that is, from the end output to the middle output. Then, the current is uniformly output in the direction of the aggregated power output steel bar 5 and the bus bar 7, fundamentally blocking the conditions for generating horizontal current on the aluminum liquid surface, thereby eliminating the horizontal current generated on the aluminum liquid surface during the aluminum electrolysis process, greatly reducing the probability of accidents during the electrolysis process, and further improving the stability of the operation of the electrolytic cell. The current direction is shown in Figure 1 the arrow direction in

[0022] At the same time, due to the insulating material layer 6 between the aggregated power output steel bar 5 and the cathode carbon block 3, and the insulating material layer 6 is composed of insulating casting material, it essentially cuts off the conditions for the current in the aluminum liquid surface to take a short - circuit path, forcing the current to only pass through the electrolyte and aluminum liquid from the anode along the vertical shortest path and then enter the cathode steel bar and be aggregated for power output. The current direction is: the current flows from the anode rod → vertically enters and passes through the anode 2 → vertically enters and passes through the molten electrolyte → vertically enters and passes through the aluminum liquid → vertically enters the cathode → vertically enters the horizontal diversion steel bar 4 → enters the aggregated power output steel bar 5 → enters the bus bar 7. Thus, the possibility of generating horizontal current in the aluminum liquid is completely eliminated, greatly improving the stability of the aluminum liquid surface during the production process. At the same time, due to the stable aluminum liquid surface, the pole pitch, that is, the distance from the bottom of the anode to the aluminum liquid surface, can be significantly shortened during the production process, reducing the voltage of the electrolytic cell and significantly reducing the power consumption per ton of aluminum, bringing a technical revolution to the production of electrolytic aluminum.

[0023] Furthermore, the length and width of the horizontal diversion steel bar 4 are not less than those of the lower bottom surface of the anode 2. Such dimensions facilitate the vertical entry of the current onto the horizontal diversion steel bar 4.

[0024] Furthermore, the horizontal diversion steel bar 4 is welded and fixed to the aggregated power output steel bar 5 or the horizontal diversion steel bar 4 and the aggregated power output steel bar 5 are integrally cast. The aggregated power output steel bar 5 is composed of a vertical section and a horizontal section connected to the horizontal diversion steel bar 4, which can enhance the overall stability of the horizontal diversion steel bar 4 and the aggregated power output steel bar 5.

[0025] In comparison with the prior art: The reason for the horizontal current generated by the electrolytic cell 1 with a conventional design is that the resistivity of the aluminum liquid is much lower than that of steel: the current flows from the anode rod → anode → molten electrolyte → aluminum liquid → cathode → cathode steel rod → and finally converges to the aluminum busbar. Since the resistivity of the molten electrolyte is extremely large, the resistance is minimized only when the current passes vertically through the electrolyte. Therefore, there is basically no horizontal current in the electrolyte. When the current passes through the electrolyte and enters the aluminum liquid surface, the current can have two directions: Route 1, the current passes vertically through the aluminum liquid → vertically enters the cathode → vertically enters the steel rod → passes through the horizontal diversion steel rod over a long distance → enters the aluminum busbar, as shown by the arrow direction in Figure 2 ; Route 2, the current enters the aluminum liquid → horizontally passes through the aluminum liquid surface → vertically enters the cathode at the power output side of the cathode end → vertically enters the steel rod → horizontally passes through the steel rod over a short distance → enters the aluminum busbar, as shown by the arrow direction in Figure 3 ; Since the resistivity of aluminum is much lower than that of steel, the resistivity of aluminum is 2.85*10 -8 Ω·m; the resistivity of steel is 1.45*10 -7 Ω·m. Therefore, the total resistance of the current passing through Route 1 is greater than that of passing through Route 2. Since the current always flows in the direction of lower total resistance, most of the current flows in the direction of Route 2. Therefore, a large amount of horizontal current is generated in the aluminum liquid surface. In the electrolytic cell with a conventional design, the current direction basically follows Route 2, as shown by the arrow direction in Figure 3 .

[0026] The above description is only a preferred embodiment of the present invention and does not impose any form of confidentiality restriction on the present invention. Any simple modification, equivalent change, and modification made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A method for forcibly changing the direction of current in an aluminum electrolytic cell, characterized in that: Based on the characteristic that current tends to the path of minimum resistance, the method changes the existing electrolytic cell current flowing horizontally in the aluminum liquid by adjusting the conductive steel rod structure and the assembly and insulation method with the cathode carbon block, so that the current enters the cathode carbon block group vertically from the aluminum liquid and then is collected to generate electricity, thus avoiding the harm caused by the horizontal current; the method of adjusting the conductive steel rod structure and the assembly and insulation method with the cathode carbon block includes: A horizontal guide steel rod (4) and a power-collecting steel rod (5) are arranged in parallel in the cathode carbon block group to form a composite conductive network. The power-collecting steel rod (5) is subjected to full surface insulation coating treatment. At the same time, a high-impedance insulating casting material layer is filled at the contact interface between the steel rod and the cathode carbon block. The resistance ratio of the horizontal / vertical path is determined by calculation to be ≥10 3 , ensuring that the vertical path forms an absolute conductive advantage.

2. The method for forcibly changing the current flow in an aluminum electrolysis cell according to claim 1, characterized in that: The flow of current in the electrolytic cell of this method is as follows: current flows from the anode guide rod → vertically enters and passes through the anode (2) → vertically enters and passes through the molten electrolyte → vertically enters and passes through the aluminum liquid → vertically enters the cathode → vertically enters the horizontal guide steel rod (4) → enters the electricity collecting steel rod (5) → enters the busbar (7).

3. The method for forcibly changing the current flow in an aluminum electrolysis cell according to claim 1, characterized in that: The structure of the method for eliminating horizontal current in an aluminum electrolytic cell comprises an electrolytic cell body (1), on which an anode (2) and a cathode carbon block (3) are arranged, a horizontal current guide steel rod (4) is arranged in the cathode carbon block (3) directly below the anode (2), a current collecting steel rod (5) is connected to the middle of the horizontal current guide steel rod (4), the current collecting steel rod (5) is wrapped with an insulating material layer (6), and the end of the current collecting steel rod (5) is connected to a busbar (7).

4. The method for forcibly changing the current flow in an aluminum electrolysis cell according to claim 3, characterized in that: The length and width of the horizontal guide steel rod (4) are not less than the length and width of the lower bottom surface of the anode (2).

5. The method for forcibly changing the current flow in an aluminum electrolysis cell according to claim 3, characterized in that: The horizontal flow guiding steel rod (4) and the power collecting steel rod (5) are fixed by welding or the horizontal flow guiding steel rod (4) and the power collecting steel rod (5) are integrally cast.

6. The method for forcibly changing the direction of current in an aluminum electrolysis cell according to any one of claims 3 to 5, characterized in that: The electricity-collecting steel rod (5) consists of a vertical section and a horizontal section connected to the horizontal guide steel rod (4).

Images