Inner lining structure of an electrolytic cell

Abstract

The present invention provides a lining structure for an electrolytic cell, aiming to solve the problem of energy waste in the prior art during the use of the electrolytic cell. A lining structure for an electrolytic cell is provided, including: a cell bottom plate; a cell side plate in a "mouth" shape, installed on the top of the cell bottom plate, and an installation area is formed between the top of the cell bottom plate and the middle of the cell side plate after installation; a refractory heat-insulating structure, installed in the installation area; a cathode mechanism, installed on the refractory heat-insulating structure; the cathode mechanism includes: a cathode carbon block; a conductive plate, installed at the bottom of the cathode carbon block; a cathode conductive rod, installed at the bottom of the conductive plate, and one end of which extends out of the installation area; an insulating mounting plate, one end of which is installed at both ends of the conductive plate, and the other end is connected to the refractory heat-insulating structure, and an installation opening for the cathode conductive rod to pass through is provided on the insulating mounting plate; wherein, the insulating mounting plate is cast from phosphor cast iron. The present invention reduces energy loss by changing the lining structure of the electrolytic cell.

Description

Technical Field

[0001] The present invention relates to the technical field of electrolysis equipment, and in particular to a lining structure of an electrolytic cell. Background Art

[0002] For more than a hundred years, the industrial production of electrolytic aluminum has always been the Hall-Héroult process, that is, direct current is passed through a fluoride salt system (electrolyte) containing alumina. Oxygen reacts with carbon on the anode to produce carbon dioxide and carbon monoxide, and elemental aluminum is deposited on the cathode to complete the electrochemical oxidation-reduction reaction. When direct current enters the electrolytic cell, it first vertically passes through the carbon anode, passes through the electrolyte and the molten aluminum layer, and then horizontally converges in the cathode and the cathode steel bars to the external cathode busbar of the cell, and then enters the next cell through the column busbar. After the direct current passes through several electrolytic cells in sequence, an electrolytic circuit, that is, an electrolytic series, is formed. The direct current flows horizontally out in the cathode and steel bars of the electrolytic cell, that is, a vertical magnetic field is generated in the aluminum liquid layer. Since the cathode is composed of multiple groups, the vertical magnetic fields in the middle part can partially cancel each other out, and the vertical magnetic field at the end cannot be cancelled, resulting in a very large vertical magnetic field at the end part, and the vertical magnetic fields at the four corners of the end are antisymmetric. Since the resistance of the aluminum liquid is much smaller than that of the cathode carbon block and the steel bar, a horizontal current is generated in the aluminum liquid, and this current generates a large magnetic force under the action of the vertical magnetic field, making the fluctuating surface of the aluminum liquid unstable, and the interpolar distance can only be reduced to a certain extent, that is, the cell voltage cannot be further reduced for energy saving. Summary of the Invention

[0003] In order to solve the problem of energy waste in the existing electrolytic cell during use, the present invention provides a lining structure of an electrolytic cell to reduce energy loss by changing the lining structure of the electrolytic cell.

[0004] The technical solution adopted by the present invention is as follows:

[0005] A lining structure of an electrolytic cell, comprising:

[0006] A cell bottom plate;

[0007] A cell side plate in a "mouth" shape, installed on the top of the cell bottom plate. After installation, an installation area is formed between the top of the cell bottom plate and the middle part of the cell side plate;

[0008] A refractory insulation structure, installed in the installation area;

[0009] A cathode mechanism, installed on the refractory insulation structure;

[0010] Wherein, the cathode mechanism includes:

[0011] A cathode carbon block;

[0012] A conductive plate, installed at the bottom of the cathode carbon block;

[0013] The cathode conductive bar is installed at the bottom of the conductive plate, and one end thereof extends out of the installation area;

[0014] The insulating mounting plate has one end mounted at both ends of the conductive plate and the other end connected to the refractory heat-insulating structure. An installation opening for the cathode conductive bar to pass through is provided on the insulating mounting plate;

[0015] Wherein, the insulating mounting plate is cast from phosphor cast iron.

[0016] Optionally, an auxiliary support plate is provided in the middle of the conductive plate, and the auxiliary support plate is made of high-alumina bricks.

[0017] Optionally, the cathode conductive bar is a high-conductivity steel bar or a steel bar embedded with a copper bar having a diameter of at least 60 mm; the bottom plate of the groove is a high-strength ceramic limiting plate with a thickness of at least 10 mm.

[0018] Optionally, the refractory heat-insulating structure includes:

[0019] The heat-insulating board is installed on the top of the bottom plate of the groove;

[0020] The heat-preserving board is installed on the side of the heat-insulating board away from the bottom plate of the groove;

[0021] The corrosion-resistant heat-preserving board is installed on the side of the heat-preserving board away from the heat-insulating board;

[0022] The dry anti-seepage material is filled between the cathode mechanism and the corrosion-resistant heat-preserving board.

[0023] Optionally, the heat-insulating board is a hard calcium silicate heat-insulating board, and there are two pieces. The thickness of each heat-insulating board is at least 50 mm; the heat-preserving board is a vermiculite heat-preserving board with a thickness of at least 65 mm.

[0024] Optionally, the top of the bottom plate of the groove, the top of the refractory heat-insulating structure and the groove side plate are connected by surrounding paste;

[0025] The groove side plate includes:

[0026] The nano heat-insulating board forms the installation area with the bottom plate of the groove;

[0027] The vermiculite heat-preserving board is installed on one side of the nano heat-insulating board and is located within the installation area;

[0028] The side carbon block is arranged on the side of the vermiculite heat-preserving board away from the nano heat-insulating board;

[0029] Wherein, the side carbon block is wet-laid with silicon carbide fire clay.

[0030] Optionally, a plurality of high-aluminum bricks are provided at one end of the top of the refractory heat-insulating structure away from the cathode conducting rod, and the high-aluminum bricks are connected by high-strength castable.

[0031] Optionally, a small nano-insulation board and a semi-graphitized corner carbon block are provided at one end of the top of the refractory heat-insulating structure close to the cathode conducting rod. The small nano-insulation board is arranged close to the nano-insulation board, and the semi-graphitized corner carbon block is connected to the small nano-insulation board through corner ramming paste.

[0032] Optionally, a liquid collecting plate is provided on the outer side wall of the cell bottom plate. The top of the liquid collecting plate has a liquid collecting groove. One end of the liquid collecting plate is provided with a drainage pipe, and a metering valve is arranged on the drainage pipe.

[0033] Optionally, the signal output end of the metering valve is connected to the signal input end of the controller, and the signal output end of the controller is connected to the signal input end of the emergency switch.

[0034] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0035] 1. By optimizing the cathode structure, the horizontal current and cathode voltage drop are reduced to the greatest extent, creating favorable conditions for reducing the cell voltage and improving the current efficiency.

[0036] 2. In combination with the adoption of the all-graphite cathode, the cathode voltage is reduced and the operating parameters such as the cell working voltage are considered. The heat insulation in the cathode area is strengthened, the heat dissipation distribution state of each area is adjusted, and the energy balance in the cathode area is basically maintained.

[0037] 3. The overall design of the lining material is carried out to improve the stability and reliability of the anti-seepage and heat-insulating materials during the whole life cycle.

[0038] 4. After the lining transformation, energy conservation, production increase, extension of the cell life, and recycling of the conducting rods can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0040] Figure 1 It is a schematic diagram of the overall structure of the lining structure of the electrolytic cell.

[0041] Figure 2 It is a schematic diagram of the partial structure of the cathode structure of the lining structure of the electrolytic cell.

[0042] Figure 3Schematic diagram of the cathode structure with copper rods for the inner lining structure of the electrolytic cell.

[0043] Figure 4 Schematic diagram of the inner lining structure of the electrolytic cell with a liquid collecting plate.

[0044] Figure 5 For Figure 4 Partial enlarged structure diagram at position A in

[0045] Reference numerals:

[0046] 1. Cell bottom plate; 2. Cell side plate; 21. Nano thermal insulation board; 22. Vermiculite thermal insulation board; 23. Side carbon block; 3. Refractory thermal insulation structure; 31. Heat insulation board; 32. Thermal insulation board; 33. Corrosion-resistant thermal insulation board; 34. Dry anti-seepage material; 4. Cathode mechanism; 41. Cathode carbon block; 42. Conductive plate; 43. Cathode conductive rod; 44. Insulating mounting plate; 45. Auxiliary support plate; 5. High-alumina brick; 6. Small nano thermal insulation board; 7. Semi-graphitic corner carbon block; 8. Liquid collecting plate; 81. Liquid collecting tank; 82. Drain pipe; 83. Metering valve. Detailed implementation manners

[0047] In the following, only some exemplary embodiments are simply described. As those skilled in the art can recognize, the described embodiments can be modified in various different ways without departing from the spirit or scope of the present invention. Therefore, the drawings and descriptions are considered to be exemplary in nature rather than restrictive.

[0048] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship when the product of the present invention is normally placed, or the orientation or positional relationship commonly understood by those skilled in the art. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention.

[0049] In the present invention, unless otherwise clearly defined and limited, terms such as "installation", "connection", "linkage", "fixation" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be directly connected, or indirectly connected through an intermediate medium, and may be the internal communication of two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0050] The following disclosure provides many different embodiments or examples for implementing different structures of the present invention. To simplify the disclosure of the present invention, the components and settings of specific examples are described below. Of course, they are only examples and are not intended to limit the present invention. In addition, the present invention may repeat reference numerals and / or reference letters in different examples. Such repetition is for the purpose of simplification and clarity, and does not itself indicate the relationship between the various embodiments and / or settings discussed. In addition, the present invention provides examples of various specific processes and materials, but those of ordinary skill in the art can be aware of the application of other processes and / or the use of other materials.

[0051] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0052] As Figure 1 、 Figure 2 and Figure 3 shown, the embodiments of the present invention provide a lining structure of an electrolytic cell, including: a cell bottom plate 1, a cell side plate 2 in a "mouth" shape, a refractory heat-insulating structure 3, and a cathode mechanism 4; the cell side plate 2 is installed on the top of the cell bottom plate 1, and after installation, an installation area is formed at the top of the cell bottom plate 1 and the middle part of the cell side plate 2. The refractory heat-insulating structure 3 is installed in the installation area. The cathode mechanism 4 is installed on the refractory heat-insulating structure 3.

[0053] Among them, the cathode mechanism 4 includes: a cathode carbon block 41, a conductive plate 42, a cathode conductive rod 43, and an insulating mounting plate 44; the conductive plate 42 is installed at the bottom of the cathode carbon block 41; the cathode conductive rod 43 is installed at the bottom of the conductive plate 42, and one end thereof extends out of the installation area; one end of the insulating mounting plate 44 is installed at both ends of the conductive plate 42, and the other end is connected to the refractory heat-insulating structure 3. An installation opening for the cathode conductive rod 43 to pass through is provided on the insulating mounting plate 44. The insulating mounting plate 44 is cast with phosphor iron.

[0054] By arranging the refractory heat-insulating structure 3 in the installation area formed between the cell bottom plate 1 and the cell side plate 2, and then installing the cathode mechanism 4 on the refractory heat-insulating structure 3, the electrolytic cell is heat-insulated by the refractory heat-insulating structure 3. This creates favorable conditions for reducing the cell voltage and improving the current efficiency during the use of this lining structure. At the same time, the cathode carbon block 41 is made entirely of graphite, which reduces the cathode voltage and operating parameters such as the cell working voltage, strengthens the heat insulation in the cathode area, adjusts the heat dissipation distribution state in each area, and maintains the basic energy balance in the cathode area.

[0055] In another embodiment, as Figure 1 shown, in another embodiment, in order to improve the stability of the cathode carbon block 41 during use, an auxiliary support plate 45 is provided in the middle of the conductive plate 42, and the auxiliary support plate 45 is made of high-alumina bricks 5.

[0056] In another embodiment, as Figure 2 and Figure 3 shown, in order to reduce the cell voltage and improve the current efficiency, the cathode conductive bar 43 is a high-conductivity steel bar or a steel bar embedded with a copper bar having a diameter of at least 60 mm.

[0057] Through experimental comparison: the horizontal current of the cathode conductive bar 43 before improvement is 0.773 (A / cm2), and the cathode voltage drop is 310 (mV); the horizontal current of the high-conductivity steel bar is 0.579 (A / cm2), and the cathode voltage drop is 230 (mV); the horizontal current of the steel bar embedded with a copper bar having a diameter of at least 60 mm is 0.418 (A / cm2), and the cathode voltage drop is 180 (mV).

[0058] In another embodiment, in order to improve the service life of the electrolytic cell, the cell bottom plate 1 is a high-strength ceramic limiting plate, and its thickness is at least 10 mm.

[0059] In another embodiment, as Figure 1 shown, the refractory heat-insulating structure 3 includes: a heat-insulating board 31, a thermal insulation board 32, a corrosion-resistant heat-insulating board 33, and a dry anti-seepage material 34; the heat-insulating board 31 is installed on the top of the cell bottom plate 1; the thermal insulation board 32 is installed on the side of the heat-insulating board 31 away from the cell bottom plate 1; the corrosion-resistant heat-insulating board 33 is installed on the side of the thermal insulation board 32 away from the heat-insulating board 31; the dry anti-seepage material 34 is filled between the cathode mechanism 4 and the corrosion-resistant heat-insulating board 33.

[0060] In another embodiment, the heat-insulating board 31 is a hard calcium silicate heat-insulating board 31, and there are two pieces, and the thickness of each heat-insulating board 31 is at least 50 mm. The thermal insulation board 32 is a vermiculite thermal insulation board 22, and its thickness is at least 65 mm. The thickness of the dry anti-seepage material 34 is at least 193 mm.

[0061] By changing the layered structure of the refractory heat-insulating structure 3 and the thickness of each corresponding layer structure, it is to facilitate improving its refractory heat-insulating performance. Among them, the vermiculite insulation board 22 has the advantages of flame retardancy, heat insulation, and high temperature resistance. After a long period of high-temperature roasting, it can still maintain its integrity. It is environmentally friendly because it is composed of inorganic materials, so it does not contain toxic substances such as formaldehyde and benzene, and even at high temperatures, it does not release toxic and harmful gases.

[0062] In another embodiment, as Figure 1 shown, the top of the tank bottom plate 1 and the refractory heat-insulating structure 3 are connected to the tank side plate 2 by surrounding paste; the tank side plate 2 includes: a nano heat-insulating plate 21 and a vermiculite heat-insulating side carbon block 23.

[0063] The nano heat-insulating plate 21 forms the installation area with the tank bottom plate 1; the vermiculite insulation board 22 is installed on one side of the nano heat-insulating plate 21 and is located within the installation area; the side carbon block 23 is arranged on the side of the vermiculite insulation board 22 away from the nano heat-insulating plate 21; wherein, the side carbon block 23 is wet-laid with silicon carbide fire clay.

[0064] The side wall carbon block and the cathode mechanism 4 are connected together by surrounding paste. At the same time, heat insulation is carried out through the vermiculite insulation board 22.

[0065] In another embodiment, a plurality of high-aluminum bricks 5 are provided at one end of the top of the refractory heat-insulating structure 3 far from the cathode conducting rod 43, and the high-aluminum bricks 5 are connected by high-strength castable.

[0066] In another embodiment, a small nano heat-insulating plate 6 and a semi-graphite corner carbon block 7 are provided at one end of the top of the refractory heat-insulating structure 3 close to the cathode conducting rod 43. The small nano heat-insulating plate 6 is arranged close to the nano heat-insulating plate 21, and the semi-graphite corner carbon block 7 is connected to the small nano heat-insulating plate 6 by corner ramming paste.

[0067] In another embodiment, as Figure 4 and Figure 5 shown, a liquid collecting plate 8 is provided on the outer side wall of the tank bottom plate 1. The top of the liquid collecting plate 8 has a liquid collecting groove 81. One end of the liquid collecting plate 8 is provided with a drainage pipe 82, and a metering valve 83 is provided on the drainage pipe 82. It is to facilitate that when the electrolytic cell leaks, the electrolyte overflows into the liquid collecting groove 81 and then is discharged through the metering valve 83. When the metering valve 83 detects that there is liquid flowing through, it alarms at the same time to remind the staff to conduct manual inspection.

[0068] In another embodiment, in order to further improve the safety during use, the signal output end of the metering valve 83 is connected to the signal input end of the controller, and the signal output end of the controller is connected to the signal input end of the emergency switch. During use, first, a warning value of the throughput of the metering valve 83 is preset. When the liquid passing through the metering valve 83 is greater than this warning value, while giving an alarm, the cathode switch is controlled to close. This further ensures the personal safety of the operator.

[0069] Decomposition of cell voltage before and after the lining transformation:

[0070] Table 1

[0071]

[0072] Comparison of main technical and economic indicators before and after the lining transformation:

[0073] Table 2

[0074]

[0075] As can be seen from Table 2, compared with the original plan, the first transformation plan can achieve a power saving of 291 kWh / t of aluminum, meeting the grading index of the stepped electricity price in 2022 (the comprehensive AC power consumption of aluminum liquid ≤ 13650 kWh / t); the second transformation plan can achieve a power saving of 473 kWh / t of aluminum compared with the original plan, meeting the grading index of the stepped electricity price in 2023 (the comprehensive AC power consumption of aluminum liquid ≤ 13450 kWh / t).

[0076] Benefit analysis before and after the transformation:

[0077] Table 3

[0078]

[0079] As can be analyzed from Table 3, the incremental investment payback period for adopting the first lining transformation plan is 3.12 years, and the incremental investment payback period for adopting the second lining transformation plan is 3.34 years.

[0080] If the impact of the additional electricity charges of the stepped electricity price policy on the production cost is superimposed (see Table 4 for details), the incremental investment payback period for adopting the first lining transformation plan will be significantly shortened to 0.33 years, and the incremental investment payback period for adopting the second lining transformation plan will be significantly shortened to 0.32 years, and the return on investment will be significantly improved.

[0081] Table 4

[0082]

[0083] Finally, it should be noted that the above are only preferred embodiments of the present invention and are not used to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or perform equivalent replacements on some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. An inner lining structure of an electrolytic cell, characterized in that, Comprising: Tank bottom plate; Tank side plates in a "mouth" shape, installed on the top of the tank bottom plate, and after installation, an installation area is formed between the top of the tank bottom plate and the middle of the tank side plates; Refractory and heat-insulating structure, installed in the installation area; Cathode mechanism, installed on the refractory and heat-insulating structure; The cathode mechanism includes: Cathode carbon block; Conductive plate, installed at the bottom of the cathode carbon block; Cathode conductive rod, installed at the bottom of the conductive plate, and one end thereof extends out of the installation area; Insulating mounting plate, one end of which is installed at both ends of the conductive plate, and the other end is connected to the refractory and heat-insulating structure. An installation opening for the cathode conductive rod to pass through is provided on the insulating mounting plate; Wherein, the insulating mounting plate is cast from phosphorus cast iron.

2. The lining structure of the electrolytic cell according to claim 1, characterized in that, An auxiliary support plate is provided in the middle of the conductive plate, and the auxiliary support plate is made of high-alumina bricks.

3. The lining structure of the electrolytic cell according to claim 1 or 2, characterized in that, The cathode conductive rod is a high-conductivity steel rod or a steel rod embedded with a copper rod with a diameter of at least 60 mm; the tank bottom plate is a high-strength ceramic limiting plate with a thickness of at least 10 mm.

4. The inner lining structure of the electrolytic cell according to claim 1, characterized in that, The refractory and heat-insulating structure includes: Heat-insulating board, installed on the top of the tank bottom plate; Insulation board, installed on the side of the heat-insulating board away from the tank bottom plate; Corrosion-resistant insulation board, installed on the side of the insulation board away from the heat-insulating board; Dry anti-seepage material, filled between the cathode mechanism and the corrosion-resistant insulation board.

5. The inner lining structure of the electrolytic cell according to claim 4, characterized in that, The heat-insulating board is a hard calcium silicate heat-insulating board, and there are two pieces. The thickness of each heat-insulating board is at least 50 mm; the insulation board is a vermiculite insulation board with a thickness of at least 65 mm.

6. The inner lining structure of the electrolytic cell according to claim 1, characterized in that, The top of the tank bottom plate and the refractory and heat-insulating structure are connected to the tank side plates by perimeter paste; The tank side plates include: Nano heat-insulating board, forming the installation area with the tank bottom plate; Vermiculite insulation board, installed on one side of the nano heat-insulating board and located within the installation area; Side carbon block, arranged on the side of the vermiculite insulation board away from the nano heat-insulating board; Wherein, the side carbon block is wet-laid with silicon carbide fire clay.

7. The inner lining structure of the electrolytic cell according to claim 6, characterized in that, Multiple high-alumina bricks are provided at the end of the top of the refractory and heat-insulating structure away from the end where the cathode conductive rod extends, and the high-alumina bricks are connected by high-strength casting material.

8. The inner lining structure of the electrolytic cell according to claim 6, characterized in that, A small nano heat-insulating board and a semi-graphite corner carbon block are provided at the end of the top of the refractory and heat-insulating structure close to the cathode conductive rod. The small nano heat-insulating board is arranged close to the nano heat-insulating board, and the semi-graphite corner carbon block is connected to the small nano heat-insulating board by corner ramming paste.

9. The inner lining structure of the electrolytic cell according to claim 1, characterized in that, A liquid collecting plate is provided on the outer side wall of the tank bottom plate. The top of the liquid collecting plate has a liquid collecting groove, and a drainage pipe is provided at one end of the liquid collecting plate. A metering valve is provided on the drainage pipe.

10. The inner lining structure of the electrolytic cell according to claim 9, characterized in that, The signal output end of the metering valve is connected to the signal input end of the controller, and the signal output end of the controller is connected to the signal input end of the emergency switch.

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