Cathode carbon block composite assembly structure for aluminum electrolysis cell

Abstract

The utility model belongs to the technical field of aluminum electrolysis, and particularly relates to a cathode carbon block composite type assembly structure for an aluminum electrolysis cell, at least one mounting groove is formed in the upper end of a cathode carbon block, a group of steel bars are arranged in the mounting groove, and each group of steel bars comprises two steel bars which are symmetrically arranged in the mounting groove at a fixed interval; the upper end of the steel bar protrudes out of the upper surface of the cathode carbon block; the cathode carbon block and the steel bar are cast and fixed through a phosphorus pig iron layer; the mounting groove between the two steel bars is hollow to form a center joint filling area, and the center joint filling area and the upper surface of the cathode carbon block between the two steel bars are filled with a middle steel bar paste layer; and a pouring layer as high as the steel bar is poured on the upper surface of the cathode carbon block on two sides of the steel bar paste layer. The structure can effectively reduce the horizontal heat dissipation of the end part of the cathode carbon block, reduces the contact pressure drop between the cathode carbon block and the cathode steel bar, is favorable for forming good furnace wall and extension leg shapes, and improves the magnetofluid stability and heat balance stability of the electrolytic bath.

Description

Technical Field

[0001] The utility model belongs to the technical field of aluminum electrolysis, and in particular relates to a composite assembly structure of cathode carbon blocks for aluminum electrolysis cells. Background Art

[0002] To support the "Integrated Application Demonstration Project of Green Aluminum High-Efficiency and Low-Consumption Overhaul Tank Energy-Saving Technology", and complete the target tasks of "the comprehensive alternating current consumption of aluminum liquid ≤ 13450 kWh / T in 2023 and ≤ 13300 kWh / T in 2025", by carrying out the phosphor iron casting of all-graphite cathode carbon blocks, the energy-saving and consumption-reducing level is further improved. However, the original assembly structure of the cathode carbon blocks has uneven horizontal current distribution, resulting in too good electrical conductivity in places with low electrical conductivity requirements, accelerating cathode loss, and the artificial extension legs not forming effective protection, leading to early damage of the aluminum electrolysis cell.

[0003] For example, the invention patent with the publication number CN102560540B discloses a phosphor iron cast cathode assembly carbon block. According to the aluminum electrolysis principle and current distribution requirements, two-section steel bars and a full-length steel bar are selected. The two-section steel bars and the full-length steel bar cathode carbon blocks are at the corresponding positions in the middle of the two anodes, filled with non-conductive materials, and the outside of the positive projection of the anode is filled with the same non-conductive materials; at the position of the artificial extension leg, pre-molding is adopted, and the molding shape is set according to the parabola of the function y = x2. The novel phosphor iron cast cathode assembly carbon block of this invention can increase the cathode current density by 5-7%, effectively solving the problem of insufficient heat capacity of the phosphor iron cast cathode cell.

[0004] The horizontal heat dissipation at the cathode end of this type of patent is still sufficient, and the extension leg in the tank is too long, which is prone to cause the risk of leakage of the electrolysis cell. This defect is particularly obvious in electrolysis cells using graphitized cathodes. At the same time, the cathode steel bar and the cathode carbon block of this structure are connected by the phosphor iron casting method, and the electrical conductivity in the middle of the steel bar and the cathode carbon block is not high enough, resulting in insufficient uniformity of the horizontal current distribution during the use of the electrolysis cell, and further reducing the magnetohydrodynamic stability and thermal balance stability of the electrolysis cell. Summary of the Utility Model

[0005] In view of the technical problems existing in the background art, the utility model provides a composite assembly structure of cathode carbon blocks for aluminum electrolysis cells.

[0006] To achieve the above object, the technical solution provided by the utility model is as follows:

[0007] A composite assembly structure of a cathode carbon block for an aluminum electrolysis cell, comprising a cathode carbon block and steel bars. At least one installation groove is formed in the upper end of the cathode carbon block. A group of steel bars is arranged in the installation groove. Each group of steel bars includes two steel bars that are fixedly spaced at a certain distance and symmetrically arranged in the installation groove. The upper ends of the steel bars protrude above the upper surface of the cathode carbon block. The cathode carbon block and the steel bars are fixed by casting with a layer of ferrophosphorus. Thus, a U-shaped ferrophosphorus casting layer is formed between the cathode carbon block and the steel bars. Both ends of the installation groove are left empty and filled with side cold ramming paste layers. The installation groove between the two steel bars is hollow to form a middle seam filling area. The upper surface of the cathode carbon block in the middle seam filling area and between the two steel bars is filled with a middle steel bar paste layer. Pouring layers are cast on the upper surfaces of the cathode carbon block on both sides of the middle steel bar paste layer.

[0008] Optionally, anchoring steel bars are welded on both sides of each steel bar exposed above the upper part of the cathode carbon block. The anchoring steel bars are arranged in the pouring layer.

[0009] Optionally, an anti-seepage casting layer is cast on the upper surface of the steel bar and the upper surface of the pouring layer.

[0010] Optionally, the installation groove includes a vertical groove section located on both side walls of the cathode carbon block and an inclined groove section located on the bottom wall of the cathode carbon block. The inclined groove section extends obliquely towards the outside of the cathode carbon block.

[0011] Optionally, there is one installation groove. Two steel bars are symmetrically arranged in one installation groove. The anchoring steel bars on both sides of the two steel bars are symmetrically arranged, and the anchoring steel bars are perpendicular to the side surface of the steel bar.

[0012] Optionally, there are two installation grooves. Four steel bars are symmetrically arranged in the two installation grooves. The outermost anchoring steel bars of the four steel bars are symmetrically arranged. The inner anchoring steel bars of the four steel bars are arranged in a staggered manner, and the anchoring steel bars are perpendicular to the side surface of the steel bar.

[0013] Optionally, vertical anchoring bars are respectively arranged at the bottom ends of the anchoring steel bars symmetrically arranged on each steel bar. The anchoring steel bars and the vertical anchoring bars are perpendicular to each other. The vertical anchoring bars are arranged closely against the side wall of the steel bar. The bottom ends of the two vertical anchoring bars are connected with a bottom anchoring bar. The bottom anchoring bar is arranged closely against the bottom wall of the steel bar. The two vertical anchoring bars and the bottom anchoring bar are arranged in a U shape. And both ends of the bottom anchoring bar enter the inclined groove section for arrangement. The bottom anchoring bar and the vertical anchoring bars are arranged in the ferrophosphorus casting layer.

[0014] The utility model has the following advantages and beneficial effects:

[0015] According to the aluminum electrolysis principle and the requirement of current distribution, the present utility model connects the cathode steel bar and the cathode carbon block by means of casting with ferrophosphorus. A middle steel bar paste layer is filled on the upper surface of the cathode carbon block in the middle seam filling area and between the two steel bars, and highly conductive steel bar paste is filled in the middle position, so that the carbon block group has good conductivity efficiency, the horizontal current distribution is uniform during the use of the electrolytic cell, the contact voltage drop between the cathode carbon block and the cathode steel bar is reduced, and further the bottom voltage drop of the electrolytic cell is reduced, which is beneficial to forming a good furnace lining and leg shape; both ends of the installation groove are left empty and filled with a side cold ramming paste layer, which is filled with a non-conductive material with better plasticity. A pouring layer is cast on the upper surface of the cathode carbon block on both sides of the cold ramming paste layer to cover the steel bar, allowing the steel bar to thermally expand without affecting the cathode carbon block, effectively suppressing the stress deformation caused by the thermal expansion of the steel bar, effectively reducing the horizontal heat dissipation at the end part of the cathode carbon block, which is beneficial to forming a good furnace lining and leg shape, improving the magnetohydrodynamic stability and thermal balance stability of the electrolytic cell, and thus reducing the probability of leakage at this place. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a structural diagram of the cathode carbon block provided by the present utility model;

[0017] Figure 2 It is Figure 1 the front view of

[0018] Figure 3 It is a structural diagram of the connection between the cathode carbon block and the steel bar by means of a ferrophosphorus casting layer provided by the present utility model;

[0019] Figure 4 It is Figure 3 the partial enlarged view of a at

[0020] Figure 5 It is Figure 3 the front view of

[0021] Figure 6 It is Figure 5 the top view of

[0022] Figure 7 It is Figure 5 the left view of

[0023] Figure 8 It is Figure 5 the cross-sectional view along the A-A direction in

[0024] Figure 9 It is Figure 5 the cross-sectional view along the B-B direction in

[0025] Figure 10 It is a connection schematic diagram of the anchor bar, the vertical anchor bar and the horizontal anchor bar provided by the present utility model;

[0026] Figure 11 is Figure 5 a cross-sectional view along the C-C direction in

[0027] Figure 12 a structural diagram of the middle steel bar paste layer provided by the present utility model between the cathode carbon block and the steel bar;

[0028] Figure 13 is Figure 12 a partial enlarged view at position b in

[0029] Figure 14 a structural diagram of the pouring layer provided by the present utility model on the upper part of the cathode carbon block and the steel bar;

[0030] Figure 15 is Figure 14 the front view of

[0031] Figure 16 is Figure 15 the left view of

[0032] Figure 17 a structural diagram of the refractory anti-seepage casting layer provided by the present utility model on the steel bar and the pouring layer;

[0033] Figure 18 is Figure 17 the front view of

[0034] Figure 19 is Figure 18 the left view of

[0035] Icon: 1 - cathode carbon block, 11 - installation groove, 12 - vertical groove section, 13 - inclined groove section, 2 - steel bar, 21 - anchoring steel bar, 22 - middle seam filling area, 23 - bottom anchoring bar, 24 - vertical anchoring bar, 3 - phosphor cast iron layer, 4 - middle steel bar paste layer, 5 - side cold ramming paste layer, 6 - pouring layer, 7 - refractory anti-seepage casting layer. Specific embodiments

[0036] To make the objectives, technical solutions and advantages of the embodiments of the present utility model clearer, the technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are some, but not all, of the embodiments of the present utility model.

[0037] Therefore, the following detailed description of the embodiments of the present utility model provided in the drawings is not intended to limit the scope of the claimed present utility model, but merely represents selected embodiments of the present utility model. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative efforts shall fall within the scope of protection of the present utility model.

[0038] Embodiment

[0039] As Figures 1 to 16 shown, a composite assembly structure of a cathode carbon block for an aluminum electrolysis cell includes a cathode carbon block 1 and a steel bar 2. At least one installation groove 11 is provided at the upper end of the cathode carbon block 1. A group of steel bars 2 is arranged in the installation groove 11. Each group of steel bars 2 includes two steel bars 2 that are fixedly spaced apart and symmetrically arranged in the installation groove 11, that is, the two steel bars 2 located in the same installation groove 11 have a gap with each other, and the upper end of the steel bar 2 protrudes above the upper surface of the cathode carbon block 1. The cathode carbon block 1 and the steel bar 2 are fixed by casting with phosphor cast iron, so as to form a U-shaped phosphor cast iron casting layer 3 between the cathode carbon block 1 and the steel bar 2 (as Figure 9 shown), and both ends of the installation groove 11 are left empty and filled with a side cold ramming paste layer 5, which plays the roles of absorbing thermal deformation, anti-seepage protection, reducing horizontal heat dissipation at the end part, and insulation. The installation groove 11 between the two steel bars 2 is hollow to form a middle seam filling area 22, and the upper surface of the cathode carbon block 1 between the middle seam filling area 22 and the two steel bars 2 is filled with a middle steel bar paste layer 4, which plays the roles of high conductivity and uniform distribution of horizontal current. Pouring layers 6 having the same height as the steel bars 2 are poured on the upper surfaces of the cathode carbon blocks 1 on both sides of the middle steel bar paste layer 4, which play the roles of absorbing thermal deformation and anti-seepage protection.

[0040] The middle steel bar paste layer 4 is a high-conductivity material, and its main components include aggregate and binder. Among them, the aggregate is mainly electrically calcined coal and graphite, and the binder is mainly resin. The middle steel bar paste layer 4 facilitates the uniform distribution of current between the steel bar 2 and the cathode carbon block 1, and the current density is uniform; the side cold ramming paste layer 5 filled at the end is SiC ramming material, which is a non-conductive plastic material. Because the end of the cathode carbon block 1 group is in contact with the electrolysis cell and there are people operating outside, electricity needs to be isolated. At the same time, the upper surface of the steel bar 2 is coated with SiC ramming material for insulation. Similarly, the steel bars 2 extending to both sides of the cathode carbon block 1 need to pass through the electrolysis cell to the outside and need to be coated with insulating material.

[0041] The upper pouring layer 6 mainly plays the roles of filling and protection. Filling means that after pouring the casting material, it is flush with the upper part of the steel bar 2, so that the steel bar 2 is not directly exposed outside. During the electrolysis process, the cathode loss will not reach the position of the steel bar 2. If the cathode carbon block 1 and the steel bar 2 are of the same height, the height of the cathode carbon block will increase. Therefore, the steel bar 2 is exposed, and the pouring layer 6 is poured, and the height of the cathode carbon block 1 will be shortened.

[0042] In this structure, the cathode steel bar 2 and the cathode carbon block 1 are connected by means of casting with ferrophosphorus, and the middle part is filled with high-conductivity steel bar paste, so that the carbon block group has good conductivity efficiency, the horizontal current distribution is uniform during the use of the electrolytic cell, the contact voltage drop between the cathode carbon block and the cathode steel bar is reduced, and the bottom voltage drop of the electrolytic cell is further reduced; it achieves the effects of increasing the current density and facilitating the formation of an effective hearth, can effectively reduce the horizontal heat dissipation at the end part of the cathode carbon block 1, is conducive to the formation of a good hearth and ledge shape, improves the magnetohydrodynamic stability and thermal balance stability of the electrolytic cell, and thus reduces the probability of leakage at this place.

[0043] Furthermore, on both sides of each steel bar 2 exposed above the cathode carbon block 1, anchoring steel bars 21 are welded, and the anchoring steel bars 21 are arranged in the pouring layer 6 to enhance the connection strength between the pouring layer 6, the cathode carbon block 1 and the steel bar 2.

[0044] As Figures 17 to 19 shown, furthermore, a refractory, high-strength and anti-seepage pouring layer 7 is cast on the upper surface of the steel bar 2 and the upper surface of the pouring layer 6. Here, the anti-seepage pouring layer 7 can be cast after the pouring layer 6 is poured, or the anti-seepage pouring layer 7 and the pouring layer 6 can be poured together, which can further provide fire resistance and anti-seepage performance, but will increase the height of the cathode carbon block 1.

[0045] As Figure 1 、 Figure 2 shown, furthermore, the installation groove 11 includes a vertical groove section 12 located on both side walls of the cathode carbon block 1 and an inclined groove section 13 located on the bottom wall of the cathode carbon block 1, and the inclined groove section 13 extends obliquely outward from the cathode carbon block 1. With such a design, a U-shaped ferrophosphorus casting layer 3 is cast, and the bottom end of the ferrophosphorus casting layer 3 is embedded in the inclined groove section 13, so that the ferrophosphorus and the cathode carbon block 1 are stably connected, ensuring that the ferrophosphorus casting layer 3, the cathode carbon block 1 and the steel bar 2 are stably connected as a whole and increasing the connection strength. When casting the ferrophosphorus layer, the connection strength between the ferrophosphorus layer and the steel bar 2 is greater than the connection strength between the ferrophosphorus layer and the cathode carbon block 1. Therefore, with such a design, if there are problems during the casting of the ferrophosphorus layer, such as unqualified casting, the steel bar 2 and the whole ferrophosphorus layer can be pulled out by a pulling device to be separated from the cathode carbon block 1, the steel bar 2 and the ferrophosphorus casting layer 3 attached to the steel bar 2 can be removed, and then secondary assembly and casting can be carried out again.

[0046] As a preferred embodiment of the present invention, one installation groove 11 is provided and is arranged at the center of the cathode carbon block 1. Two steel bars 2 are symmetrically arranged in one installation groove 11, the anchoring steel bars 21 on both sides of the two steel bars 2 are symmetrically arranged, and the anchoring steel bars 21 are perpendicular to the side surface of the steel bar 2.

[0047] As another preferred embodiment of the present utility model, there are two installation grooves 11, and four steel bars 2 are symmetrically arranged in the two installation grooves 11. The outermost anchoring steel bars 21 of the four steel bars 2 are symmetrically arranged, and the anchoring steel bars 21 inside the four steel bars 2 are arranged in a staggered manner, and the anchoring steel bars 21 are perpendicular to the side surface of the steel bars 2.

[0048] As Figure 10 shown, furthermore, vertical anchoring bars 24 are respectively arranged at the bottoms of the symmetrically arranged anchoring steel bars 21 on each steel bar 2. The anchoring steel bars 21 and the vertical anchoring bars 24 are perpendicularly arranged, and the vertical anchoring bars 24 are arranged close to the side wall of the steel bars 2; the bottoms of the two vertical anchoring bars 24 are connected with a bottom anchoring bar 23, and the bottom anchoring bar 23 is arranged close to the bottom wall of the steel bars 2. The two vertical anchoring bars 24 and the bottom anchoring bar 23 are arranged in a U shape, and both ends of the bottom anchoring bar 23 enter the inclined groove section 13 for setting, and the bottom anchoring bar 23 and the vertical anchoring bars 24 are arranged in the phosphor cast iron casting layer 3. Such a design further strengthens the connection strength of the pouring layer 6, the steel bars 2, the cathode carbon block 1, and the phosphor cast iron casting layer 3.

[0049] The above are only the preferred embodiments of the present utility model and are not used to limit the present utility model. For those skilled in the art, the present utility model can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present utility model shall be included within the protection scope of the present utility model.

Claims

1. A composite cathode carbon block assembly structure for an aluminum electrolytic cell, characterized in that : Including cathode carbon blocks and steel rods, At least one mounting groove is provided at the upper end of the cathode carbon block, and a group of steel bars are arranged in the mounting groove, each group of steel bars includes two steel bars spaced at a fixed distance and symmetrically arranged in the mounting groove, and the upper ends of the steel bars protrude from the upper surface of the cathode carbon block; The cathode carbon block and the steel rod are fixed by casting a phosphorus pig iron layer, so that a U-shaped phosphorus pig iron casting layer is formed between the cathode carbon block and the steel rod, and both ends of the installation groove are left empty and filled with a side cold ramming paste layer; The installation groove between the two steel bars is hollow to form a middle seam filling area, and the middle seam filling area and the upper surface of the cathode carbon block between the two steel bars are filled with a middle steel bar paste layer; A pouring layer having the same height as the steel rod is poured on the upper surface of the cathode carbon block on both sides of the middle steel rod paste layer.

2. The cathode carbon block composite assembly structure for aluminum electrolytic cell according to claim 1, characterized in that: Anchor steel bars are welded on both sides of each steel rod exposed on the upper part of the cathode carbon block, and the anchor steel bars are arranged in the pouring layer.

3. The cathode carbon block composite assembly structure for aluminum electrolytic cell according to claim 1, characterized in that: An anti-seepage casting layer is cast on the upper surface of the steel rod and the upper surface of the casting layer.

4. The cathode carbon block composite assembly structure for aluminum electrolytic cell according to claim 2, characterized in that: The mounting groove comprises vertical groove sections located at two side walls of the cathode carbon block and an inclined groove section located at the bottom wall of the cathode carbon block, and the inclined groove section extends obliquely toward the outside of the cathode carbon block.

5. The cathode carbon block composite assembly structure for aluminum electrolytic cell according to claim 4, characterized in that: The installation groove is provided with one, two steel bars are symmetrically arranged in one installation groove, the anchoring steel bars on both sides of the two steel bars are symmetrically arranged, and the anchoring steel bars are perpendicular to the side surfaces of the steel bars.

6. The cathode carbon block composite assembly structure for aluminum electrolytic cell according to claim 4, characterized in that: There are two installation grooves, and four steel bars are symmetrically arranged in the two installation grooves. The outermost anchor bars of the four steel bars are symmetrically arranged, and the inner anchor bars of the four steel bars are staggered and arranged, and the anchor bars are perpendicular to the side surfaces of the steel bars.

7. The cathode carbon block composite assembly structure for aluminum electrolytic cell according to claim 5 or 6, characterized in that: The bottom ends of the anchor bars symmetrically arranged on each steel bar are respectively provided with vertical anchor bars, the anchor bars and the vertical anchor bars are vertically arranged, and the vertical anchor bars are arranged close to the side walls of the steel bars; the bottom ends of the two vertical anchor bars are connected with bottom anchor bars, and the bottom anchor bars are arranged close to the bottom wall of the steel bar, the two vertical anchor bars and the bottom anchor bars are arranged in a U shape, and the two ends of the bottom anchor bars are arranged in the inclined groove section, and the bottom anchor bars and the vertical anchor bars are arranged in the phosphorus pig iron casting layer.

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