CN111996552A - Aluminum cell cathode bottom heat-insulating layer structure and construction method - Google Patents

Abstract

The invention discloses a structure and a construction method of a thermal insulation layer at the cathode bottom of an aluminum electrolytic cell, which are mainly applied to the design of the aluminum electrolytic cell structure, the manufacture of technical equipment and the production of the aluminum electrolytic cell. It is characterized in that: when the thermal insulation layer structure is implemented on the bottom of the cathode carbon block of the aluminum electrolytic cell, a material that can participate in the thermoelectrochemical reaction of the aluminum electrolytic cell and has no pollution to the electrolytic chemical composition system in the molten pool of the aluminum electrolytic cell is used as the material for constructing the aluminum electrolytic cell. The construction material of the thermal insulation layer between the upper part of the horizontal bottom plate of the electrolytic cell shell and the bottom of the cathode carbon block, so that the overhaul solid waste generated during the overhaul of the aluminum electrolytic cell can be treated without the harmless process. , it can be directly applied to the production process of electrolytic aluminum. In order to solve the problem of generating hazardous solid waste from the overhaul of aluminum electrolytic cells from the source, reduce the emission of hazardous solid waste from aluminum electrolytic cells, reduce the cost of hazardous solid waste treatment of enterprises, and protect the ecological environment.

Description

Structure and construction method of thermal insulation layer at the bottom of cathode of aluminum electrolytic cell

Technical field: The structure and construction method of the thermal insulation layer at the bottom of the cathode of an aluminum electrolytic cell described in the present invention are mainly applied to the design of the aluminum electrolytic cell structure, the manufacture of technical equipment and the production of the aluminum electrolytic cell.

Background technology: The existing general aluminum electrolytic cell tank structure is composed of side furnace wall masonry blocks, cathode carbon block steel rod groups, dry leakage material layers, thermal insulation refractory brick layers, and other masonry materials , It is constructed by masonry inside the steel shell of the aluminum electrolytic cell, thereby forming the cathode furnace molten pool structure of the aluminum electrolytic cell.

In the production process of electrolytic aluminum, the hierarchical structure of the thermoelectrochemical reaction zone in the molten pool of the cathode furnace, from the upper surface of the cathode carbon block, from bottom to top, is the aluminum liquid layer, the electrolyte liquid layer, the anode carbon block layer, and the Covering material crust insulation layer. The covering material crust insulation layer is prepared by mixing electrolyte particles and aluminum electrolysis production raw material alumina. There are three main reasons why aluminum oxide and electrolyte for electrolysis are used as the building materials for the insulation layer on the upper part of the anode carbon block of the aluminum electrolytic cell:

First, the chemical composition of the alumina and electrolyte materials used for electrolytic aluminum production has the same characteristics as the chemical composition of the material participating in the thermoelectrochemical reaction in the electrolytic cell. The characteristics of the chemical composition of the molten aluminum can be repeatedly cycled to ensure the structure of the thermal balance system of the aluminum electrolytic cell. After the upper part of the anode carbon block of the electrolytic cell, it can maintain the thermal balance of the aluminum electrolytic cell, and can meet the needs of the anode carbon block for thermal insulation and conduction; third, the covering material can form a hard material under the action of high temperature and hydrogen fluoride gas in the aluminum electrolytic cell. of the covering material crust. Prevent the overflow of hydrogen fluoride gas in the molten pool of the aluminum electrolytic cell and the heat dissipation of thermal energy.

The construction materials of the thermal insulation layer constructed in the aluminum electrolysis cell shell, the bottom of the lower surface of the cathode carbon block, and the upper part of the horizontal bottom plate at the bottom of the tank shell are used for thermal insulation of the cathode carbon block, mostly ordinary inorganic materials. Refractory materials, including dry seepage material layer, thermal insulation refractory brick thermal insulation brick layer, and other masonry materials, are some common inorganic refractory materials. These inorganic refractory materials contain silicon oxide and non-electrolytic aluminum oxide. Aluminum, and other metal impurities, if these impurities are carried into the molten pool of the aluminum electrolytic cell, they will not only pollute the electrolyte in the aluminum electrolytic cell, but also contaminate the chemical composition of the aluminum liquid. Therefore, the thermal insulation layer of the cathode carbon block is constructed. These building materials cannot be directly used in the production process of the aluminum electrolytic cell to participate in the thermoelectrochemical reaction of the aluminum electrolytic cell like the materials used to construct the thermal insulation crust layer on the upper part of the anode carbon block.

It is built in the shell of the aluminum electrolytic cell. During the long-term production process of the aluminum electrolytic cell, the thermal insulation layer at the bottom of the cathode carbon block is subjected to the impact of long-term thermal load, as well as the erosion of hydrogen fluoride, sodium metal and molten aluminum. It will cause structural damage and chemical erosion pollution of the thermal insulation layer at the bottom of the cathode of the aluminum electrolytic cell, so that it will lose or reduce the thermal insulation performance. Therefore, during the overhaul of the aluminum electrolytic cell, it is necessary to clean up these failed thermal insulation refractories from the electrolytic cell, and re-build the new thermal insulation construction materials. In order to ensure the continuous and stable production of aluminum electrolytic cells,

However, the fluoride-contaminated and failed aluminum electrolytic cell overhaul slag cleaned from the overhaul tank contains a large amount of chemical components that pollute the electrolyte molten salt material chemical system in the aluminum electrolytic cell, so it cannot be Reuse like anode top cover.

However, the solid waste generated by these overhauls, because of its chemical composition containing a large amount of fluoride and other harmful metal substances, will cause serious pollution to the surface environment and air environment, and has been listed as a hazardous solid waste material prohibited by the state. Only after harmless treatment can the solid waste be disposed of and discharged or reused.

The solid hazardous wastes in the aluminum electrolysis cathode furnace due to the tank overhaul are collectively referred to as the aluminum electrolytic cell overhaul solid waste by the electrolytic aluminum industry. Only discharge and disposal can be carried out, and the average cost of harmless treatment of hazardous solid waste per ton of overhaul is about 2,000 yuan. However, there is no mature, reliable and perfect treatment process for the harmless treatment of these aluminum electrolytic cell overhaul slag.

my country is a big producer of electrolytic aluminum, and a large amount of solid waste from aluminum electrolytic cell overhaul is produced every year. At present, its harmless treatment technology cannot meet the production needs of aluminum electrolysis enterprises and the standard requirements stipulated by the national environmental protection policy; The problem has become a pain point and short board restricting the development of my country's aluminum electrolysis industry. If it is not solved completely, it will inevitably affect the healthy development of my country's electrolytic aluminum industry.

Summary of the invention: In order to completely solve the problem of the dangerous solid waste polluting the environment at the bottom of the cathode furnace of the aluminum electrolysis cell and the construction materials of the thermal insulation layer in the tank shell during the overhaul, and reduce the treatment cost of the dangerous solid waste in the overhaul of the aluminum electrolysis cell, The invention proposes a new type of aluminum electrolytic cell cathode cell bottom insulation layer structure design and construction technical scheme,

The characteristics of the innovative technical scheme of the present invention are: when the thermal insulation layer structure is applied to the bottom of the cathode carbon block of the aluminum electrolytic cell, the chemical composition system of the electrolytic material in the molten pool of the aluminum electrolytic cell is not polluted by using a material that can participate in the thermoelectrochemical reaction of the aluminum electrolytic cell. It is used as the building material for constructing the thermal insulation layer at the bottom of the cathode carbon block in the aluminum electrolytic cell shell, so that when the aluminum electrolytic cell is overhauled, the overhaul solid waste generated by it can be used without the harmless process. It can be directly applied to the production process of electrolytic aluminum and participate in the thermoelectrochemical reaction of the aluminum electrolytic cell. In order to solve the problem of solid waste from the overhaul of aluminum electrolysis cells and deal with the problem of polluting the environment, so as to achieve the purpose of reducing the output of hazardous solid waste, reducing emissions, reducing the cost of hazardous solid waste disposal of enterprises, and protecting the ecological environment. .

1. According to the above technical scheme: when the thermal insulation layer structure is implemented on the bottom of the cathode carbon block of the aluminum electrolytic cell, alumina for electrolytic production, electrolyte for electrolytic aluminum production, and alumina and electrolyte mixture can be selected as the construction aluminum. The construction material of the thermal insulation layer at the bottom of the cathode carbon block of the electrolytic cell. It is expected that when the aluminum electrolytic cell is overhauled, the formed thermal insulation layer is overhauled and the solid waste slag material can be directly applied to the production process of electrolytic aluminum without going through a harmless process.

2. According to the above technical solution: when the thermal insulation layer structure is implemented on the bottom of the cathode carbon block of the aluminum electrolysis cell, the alumina powder for aluminum electrolysis production is selected as the construction material for constructing the thermal insulation layer at the bottom of the cathode carbon block of the aluminum electrolysis cell. , so that when the tank is overhauled, the alumina powder at the thermal insulation layer can be taken out from the bottom of the aluminum electrolytic tank, and it can be directly used for electrolytic aluminum production without harmless treatment.

3. According to the above technical scheme: when the thermal insulation layer is constructed at the bottom of the cathode carbon block of the aluminum electrolytic cell, the electrolyte particle powder for aluminum electrolytic cell production can be selected as the material for constructing the thermal insulation layer at the bottom of the cathode carbon block of the aluminum electrolytic cell. It is expected that when the tank is overhauled, the electrolyte overhaul slag at the thermal insulation layer can be taken out from the bottom of the electrolytic cell and can be directly used for electrolytic aluminum production without harmless treatment.

4. According to the above technical solution: when implementing the thermal insulation layer structure on the bottom of the cathode carbon block of the aluminum electrolytic cell, the mixed granular powder of alumina and electrolyte can be selected, and the upper covering material of the anode carbon block of the aluminum electrolytic cell can be used as the construction of the aluminum electrolytic cell. The material of the thermal insulation layer between the bottom of the cathode carbon block and the horizontal bottom plate of the tank shell; it is expected that when the tank is overhauled, the alumina and electrolyte mixture can be used there, and after being taken out from the bottom of the electrolytic tank, it can be harmless Chemical treatment, like the upper covering material of anode carbon block, is directly used in electrolytic aluminum production.

5. According to the above technical solution: when the thermal insulation layer structure is applied to the bottom of the cathode carbon block of the aluminum electrolytic cell, the molten electrolyte in the aluminum electrolytic cell can be taken out from the electrolytic cell, and then cast in a setting mold, and then condensed. After forming the shaped masonry block, it is used as a structural part to be built in the thermal insulation layer at the bottom of the cathode carbon block of the aluminum electrolytic cell; the molten electrolyte in the aluminum electrolytic cell can also be taken out from the electrolytic cell and directly cast aluminum. In the thermal insulation layer at the bottom of the cathode carbon block of the electrolytic cell, after the condensing and shaping of the crust, the thermal insulation layer at the bottom of the cathode carbon block in the image aluminum electrolytic cell is shaped; in the hope that the failure electrolyte shaping masonry block can be overhauled when the cell is overhauled. After the solid waste is taken out from the electrolytic cell, it can be directly used in electrolytic aluminum production without harmless treatment.

6. According to the above technical scheme: when the bottom of the cathode carbon block of the aluminum electrolysis cell is constructed with a thermal insulation layer, the shaped masonry block is cast with electrolyte solution or the condensed shaped crust layer is cast in the electrolytic cell, the shaped masonry block can be cast in the electrolytic cell. Reinforcement connecting steel bars are arranged in the condensed forming crust layer.

7. According to the above technical solution: when the thermal insulation layer structure is implemented on the bottom of the cathode carbon block of the aluminum electrolytic cell, the interlayer steel plate can be laid in the thermal insulation layer constructed with alumina, electrolyte and alumina and electrolyte mixture , in order to build the thermal insulation layer in layers.

8. According to the above technical solution: when the thermal insulation layer structure is implemented on the bottom of the cathode carbon block of the aluminum electrolytic cell, a layer of dry anti-leakage material can be laid between the upper part of the thermal insulation layer and the bottom of the cathode carbon block. It is expected that during the overhaul of the tank, the thermal insulation layer built on the bottom of the dry anti-leakage material layer can be overhauled, and after being taken out from the bottom of the electrolytic tank, it can be directly used for electrolytic aluminum production without harmless treatment.

9. According to the above technical solution: when the thermal insulation layer structure is applied to the bottom of the cathode carbon block of the aluminum electrolytic cell, a layer of carbon tamping paste can be laid between the upper part of the thermal insulation layer and the bottom of the cathode carbon block, in order to When the tank is overhauled, the thermal insulation layer overhauled at the lower part of the carbon tamping paste layer can be overhauled and taken out from the bottom of the electrolytic tank, and can be directly used in electrolytic aluminum production without harmless treatment.

10. According to the above technical solution: when the thermal insulation layer structure is implemented on the bottom of the cathode carbon block of the aluminum electrolytic cell, a thermal insulation warehouse can be added on the top of the horizontal bottom plate at the bottom of the original aluminum electrolytic cell shell. The heat insulation bin is a steel support structure, and a horizontal cover plate parallel to the bottom plate of the tank shell is arranged on the upper part of the steel support structure. The thermal insulation warehouse is filled with thermal insulation materials. After the construction of the thermal insulation warehouse is completed, the cathode carbon block of the aluminum electrolytic cell can be formed between the upper part of the horizontal cover plate and the bottom layer of the cathode carbon block of the aluminum electrolytic cell. In order to overhaul the aluminum electrolytic cell, the thermal insulation material on the upper part of the thermal insulation warehouse of the aluminum electrolytic cell can be overhauled, and it can be directly used in the aluminum electrolytic cell without harmless treatment. production.

The innovative technical theoretical basis of the technical solution of the present invention:

1. Alumina powder for aluminum electrolytic cell production and the upper covering material of anode carbon block composed of alumina, electrolyte, and alumina and electrolyte mixture can be used as thermal insulation for the upper and side parts of the molten pool of aluminum electrolytic cell. The construction material of the layer, the anode carbon block and the electrolyte are implemented to reflect the function of thermal insulation and anti-oxidation. Then, according to logical reasoning, these materials can be used as the insulating interlayer materials for constructing the cathode bottom of the aluminum electrolytic cell, and the functions of heat preservation and anti-oxidation to the cathode carbon block can be implemented.

2. The electrolyte used in the production of aluminum electrolytic cells, and the upper covering material of the anode carbon block composed of alumina and electrolyte mixture, in the high temperature production environment of the aluminum electrolytic cell, a hard structure can be formed on the inner side of the furnace wall of the aluminum electrolytic cell. Shell layer, the hard crust layer can not only prevent the heat dissipation of the upper part of the aluminum electrolytic cell, but also prevent the leakage of aluminum liquid and electrolyte liquid to the outside. According to logical reasoning, the mixed covering material of electrolyte and alumina electrolyte used in the production of aluminum electrolytic cells can also chemically react with hydrogen fluoride gas in the high temperature production environment of aluminum electrolytic cells after being used as the insulation material for the bottom of the cathode of aluminum electrolytic cells. , forming a hard crust thermal insulation layer at the bottom of the cathode carbon block. While preventing the heat dissipation at the bottom of the aluminum electrolytic cell, the hard crust thermal insulation layer can also use the temperature difference to prevent the metal aluminum liquid and the electrolyte liquid from leaking downwards.

3. Alumina powder, electrolyte and covering material formed by mixing alumina electrolyte for electrolytic aluminum production can be recycled without harming treatment in the process of aluminum electrolytic production because it does not pollute the chemical system of aluminum electrolytic production materials. Repeatedly participating in the thermo-electrochemical reaction of the aluminum electrolytic cell, then according to logical reasoning, after these materials are used as the thermal insulation material of the cathode carbon block of the aluminum electrolytic cell, the overhaul solid waste generated when the aluminum electrolytic cell is overhauled, It can also be used for aluminum electrolytic cell production without harmless treatment and can be recycled repeatedly.

Adopting the technical scheme of the present invention, the constructed aluminum electrolytic cell cathode bottom insulation layer structure has the following advantages:

1. The raw material alumina powder or anode covering material can be used as the structure of the thermal insulation layer at the bottom of the cathode of the aluminum electrolytic cell, which can reduce the cost of thermal insulation and refractory materials for constructing the thermal insulation layer at the bottom of the cathode of the aluminum electrolytic cell.

2. The use of bulk alumina particles or covering material particles as the construction material of the thermal insulation layer at the bottom of the cathode carbon block, the granular bulk material, compared with the existing shaped refractory brick structure, has a seamless masonry, It has the advantages of low air perforation rate, low thermal conductivity of the overall structure and high structural efficiency.

3. Use substances equal to the same chemical composition of alumina and electrolyte materials used in aluminum electrolysis production to construct the thermal insulation layer structure at the bottom of the cathode carbon block. After the thermal insulation layer, it will have a temperature difference and chemical reaction with alumina and electrolyte materials to form a hard crust (equivalent to the inversion of the displacement of the hard crust at the top of the anode carbon block and the side furnace wall) to prevent Diffusion of liquid and gaseous substances.

4. When the tank is overhauled, the hazardous solid waste containing fluoride and the thermal insulation layer at the bottom of the cathode of the aluminum electrolytic cell can be directly used for electrolytic aluminum production without going through a harmless treatment process. Therefore, it can reduce the processing cost of overhauling hazardous solid waste in aluminum electrolysis enterprises and improve the economic benefits of electrolytic aluminum enterprises. Realize the green production of electrolytic aluminum,

Description of the drawings: The technical scheme and technical features of the structure and construction method of the thermal insulation layer at the bottom of the cathode of an aluminum electrolytic cell according to the present invention are more clearly described by the accompanying drawings and the description of the specific embodiments.

Fig. 1 is a schematic diagram showing the structure of the thermal insulation layer at the bottom of the furnace of the existing aluminum electrolytic cell and the cathode.

FIG. 2 is a schematic structural diagram of Embodiment 1 of the present invention.

FIG. 3 is a schematic structural diagram of Embodiment 2 of the present invention.

FIG. 4 is a schematic structural diagram of Embodiment 3 of the present invention.

FIG. 5 is a schematic structural diagram of Embodiment 4 of the present invention.

FIG. 6 is a schematic structural diagram of Embodiment 5 of the present invention.

FIG. 7 is a schematic structural diagram of Embodiment 6 of the present invention.

FIG. 8 is a schematic structural diagram of Embodiment 7 of the present invention.

FIG. 9 is a schematic structural diagram of Embodiment 8 of the present invention.

As shown in the figure: (1) anode carbon block alumina electrolyte mixed covering material, (2) electrolyte, (3) aluminum liquid, (4) anode carbon block, (5) side furnace wall, (6) cathode carbon block, (7) cathode steel rod, (8) dry anti-leakage material, (9) refractory brick, 10 thermal insulation brick, (11) steel cell shell of electrolytic cell, (12) horizontal bottom plate of cell shell, ( 13) Alumina, (14) Interlayer steel plate, (15) Covering material powder, (16) Electrolyte particle powder, (12) Electrolyte casting block, (18) Electrolyte casting layer, (19) Reinforcing steel bar, ( 20) Carbon tamping material layer, (21) horizontal cover plate of thermal insulation warehouse, (22) supporting channel steel, (23) thermal insulation fiberboard.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS: Description of the prior art, as shown in FIG. 1 , the molten pool structure of an existing aluminum electrolytic cell is constructed of cathode carbon blocks and side furnace walls built inside the steel tank shell. The furnace wall and the upper part of the cathode carbon block form a concave molten pool conductive structure for electrolytic aluminum production.

In the production process of aluminum electrolysis, from the upper surface of the cathode carbon block to the top, the material structure levels in the molten pool of the electrolytic cell are as follows: the aluminum liquid layer, the electrolyte liquid layer, the anode carbon block layer, and the oxidized The upper covering material insulation layer of the anode carbon block composed of aluminum and electrolyte mixture; the anode carbon block insulation covering material formed by mixing alumina and electrolyte, its initial stage is in the form of bulk granular powder, and it is used in high temperature process in aluminum electrolysis cell. Under the action of hydrogen fluoride and hydrogen fluoride, it can be sintered into a hard crust, which is referred to as a cover crust. The crust layer of the covering material not only has the function of thermal insulation and anti-oxidation for the anode carbon block, but also has the function of ensuring the thermal balance of the aluminum electrolytic cell. The hard covering material crust formed by sintering alumina and electrolyte mixture for aluminum electrolytic cell has the characteristics of chemical system composition that does not pollute the material of aluminum electrolytic cell. Therefore, in the electrolytic production process, it can be crushed and granulated. Without harmless treatment, it can be used repeatedly in electrolytic aluminum production.

As the cathode thermal insulation layer at the bottom of the cathode carbon block and in the steel tank shell of the electrolytic cell, it is composed of a dry anti-seepage material layer, a thermal insulation refractory brick layer, and a thermal insulation cushion layer at the bottom. The building materials are mostly made of silicon oxide, non-electrolytic alumina, and inorganic refractory materials with high iron content, which can not only pollute the thermo-electrochemical substances in the aluminum electrolytic cell, but cannot be used for electrolytic aluminum. production process. In the long-term production process of aluminum electrolytic cells, these structural material parts will fail and deform under the erosion of fluoride, sodium fluoride and metal aluminum liquid in the aluminum electrolytic cell. When the tank is overhauled, these cathodes need to be insulated The layer construction material is cleaned and removed from the electrolytic cell. Due to the chemical composition of these materials, which can pollute the electrolyte and aluminum liquid, they cannot be reused in the production process of aluminum electrolytic cells like anode covering materials, so they can only be treated as hazardous solid waste. The core objective of the present invention is to improve the structure of the existing cathode thermal insulation material of the aluminum electrolytic cell, and to use the thermal insulation material on the upper part of the anode carbon block for the thermal insulation layer structure of the cathode carbon block of the aluminum electrolytic cell, so that the cathode of the aluminum electrolytic cell can be The material of the thermal insulation layer of the carbon block can be directly used in the production of electrolytic aluminum without harmless treatment, just like the covering material of the thermal insulation layer on the upper part of the anode carbon block. Among them, the hazardous waste materials are eliminated by the thermoelectrochemical reaction process of the aluminum electrolytic cell.

Example 1: As shown in Figure 2, the construction material of the thermal insulation layer structure at the bottom of the cathode carbon block of the aluminum electrolytic cell in this example is alumina powder for electrolytic aluminum production.

During the construction, the alumina powder is evenly distributed and filled in the horizontal bottom plate of the aluminum electrolytic cell shell and the tank shell at the bottom of the cathode carbon block.

Because industrial alumina powder not only has the characteristics of low thermal conductivity and high thermal resistance value, but also has the characteristics of low porosity and strong airtightness after filling and tamping with its granular powder material structure. Obtain good thermal insulation effect.

When using alumina powder to build the thermal insulation layer of the cathode carbon block, in order to improve the compactness and balance of the alumina powder, ensure its balanced load and pressure, and reduce the penetration rate of airtight gaps, prevent the aluminum electrolytic cell from entering The hydrogen fluoride gas, metal sodium, and aluminum liquid penetrate downwards to stabilize the structural properties of the thermal insulation layer. The overall thermal insulation layer between the horizontal plate at the bottom of the tank shell and the bottom of the cathode carbon block can also be layered.

The characteristics of its structure and technology are: when it is constructed in layers from the bottom to the top, each layer of alumina powder is filled, and after tamping and leveling, a layer of steel plate is laid on the upper part, and then a layer of steel plate is placed on the top of the steel plate interlayer. The alumina powder is then filled and leveled to build the upper layer of alumina thermal insulation layer. When building to the set height at the bottom of the cathode carbon block, after leveling the total height with alumina powder, build and install the cathode carbon block steel rod group on the upper surface of its alumina thermal insulation layer. The structure of the thermal insulation layer of the cathode carbon block of the aluminum electrolytic cell is completed.

During the long-term production process of the aluminum electrolytic cell, the fluoride, sodium ions and metal aluminum liquid leaking from the cathode carbon block will form a layer similar to the aluminum oxide powder on the upper surface of the thermal insulation layer when it contacts The eutectic solid crust layer of the side furnace side, the crust layer can not only prevent the expansion and extension of its leakage, but also can block the heat dissipation at the bottom of the aluminum electrolytic cell and the heat discharge of the gas, and prolong the life of the aluminum electrolytic cell. service life.

When the tank is overhauled, the generated alumina material can be overhauled and slag can be used as raw material for production or as a covering material without harmless treatment, and it can be directly used in the production of aluminum electrolytic cells.

Example 2: As shown in Figure 3, the construction material of the thermal insulation layer at the bottom of the cathode carbon block of the aluminum electrolytic cell in this example is the "covering material" of the upper anode carbon block commonly used in electrolytic aluminum production. The "cover" is formulated by mixing alumina and electrolyte. The use of "covering material" as the construction material for the thermal insulation layer at the bottom of the cathode carbon block has the advantages of low cost compared with the use of alumina as the construction material.

The physical and chemical properties of the "covering material" of the thermal insulation layer of the anode carbon block on the upper part of the aluminum electrolytic cell, since it can meet the thermal insulation technical conditions of the anode carbon block and the electrolytic molten pool, must be able to meet the thermal insulation technical conditions of the bottom of the cathode carbon block. Since the "covering material" can participate in the production of aluminum electrolytic cells repeatedly without harmless treatment, it can also be recycled as aluminum electrolytic cell overhaul slag without harmless treatment. Repeatedly used in the production of aluminum electrolytic cells. Since the "covering material" can form a hard crust of the covering material on the upper part of the aluminum electrolytic cell, as the thermal insulation layer of the electrolytic molten pool of the aluminum electrolytic cell, it must be used as the thermal insulation layer at the bottom of the cathode carbon block of the aluminum electrolytic cell. . The construction process method is basically the same as the process of using alumina powder to construct the thermal insulation layer at the bottom of the cathode carbon block of the aluminum electrolysis cell in Example 1. Either the overall structure of "covering material particle powder" can be adopted, or the structure can be layered.

When the aluminum electrolytic cell is overhauled, the resulting overhaul slag of the covering material can be directly used in the production of the aluminum electrolytic cell and participate in the thermoelectricity of the electrolytic aluminum without undergoing harmless treatment, just like the covering material on the upper part of the anode carbon block. chemical reaction.

As shown in Figure 3, when using powdered granular materials to construct the thermal insulation layer at the bottom of the cathode carbon block, an interlayer steel plate can be installed in the thermal insulation layer. The interlayer steel plate has the following three functional purposes: First, it is convenient for layered structure, which can improve the density ratio of powder particles in layered structure, reduce the penetration porosity of the thermal insulation layer, and improve the balance and stability of heat conduction in the horizontal direction of the thermal insulation layer; block the heat flow from the upper layer of the steel plate downward Second, it can improve the bearing capacity of the upper part of the thermal insulation layer and improve the stability of the thermal insulation layer structure. Determine whether to carry out cleaning and disposal to reduce the cost of overhaul material disposal. Relative to the horizontal floor of the tank housing. The interlayer steel plate can be arranged horizontally or vertically.

Example 3: As shown in FIG. 4 , the construction material of the thermal insulation layer at the bottom of the cathode carbon block of the aluminum electrolysis cell in this example is the electrolyte condensate block granular powder commonly used in the production of electrolytic aluminum. Hereinafter referred to as "electrolyte".

The "electrolyte" is composed of cryolite and aluminum fluoride and other substances, and is an electrolytic molten layer material in which aluminum oxide in the aluminum electrolytic cell is produced into aluminum liquid.

After the electrolyte solution in the aluminum electrolytic cell is taken out from the electrolytic cell, it is condensed to form agglomerates. These electrolyte agglomerates are crushed and sieved to make powdered granules, which can be used for the cathode carbon of the aluminum electrolytic cell. The structure of the thermal insulation layer at the bottom of the block, and the construction process method is basically the same as that of Example 1.

When the tank is overhauled, the electrolyte material overhaul slag produced can be directly used in the production of aluminum electrolytic cells without harmless treatment, and participate in the thermoelectrochemical reaction of electrolytic aluminum.

Example 4: As shown in Figure 5, the construction material of the thermal insulation layer at the bottom of the cathode carbon block of the aluminum electrolysis cell in this example can use alumina or covering material powder as the main material, as in Examples 1 and 2 2, its distinguishing technical features are:

When the bottom insulation layer of the cathode carbon block is constructed with alumina or covering material powder as the main material, a layer of electrolyte shaping bricks can be arranged in the insulation layer, and the electrolyte shaping bricks are made of aluminum electrolytic cells. molten salt electrolyte inside.

The manufacturing method of the electrolyte shaped brick layer is as follows: according to the set technical requirements, first make a shaped brick mold frame, and then pour the electrolyte liquid from the aluminum electrolytic cell into the mold frame, and after it is condensed and solidified, it can be It is used as a component of the thermal insulation layer construction material at the bottom of the cathode carbon block of the aluminum electrolysis cell.

The masonry method of the electrolyte shaped bricks is basically the same as the construction method of the heat insulation and heat preservation refractory bricks in the current general aluminum electrolytic cell. It is not described here.

In the thermal insulation layer of the cathode carbon block at the bottom of the aluminum electrolytic cell, the shaped bricks made of electrolyte not only have the characteristics of convenient material acquisition, but also the electrolyte material overhaul slag generated during the cell overhaul can be eliminated without going through It can be directly used in the production of aluminum electrolytic cells and participate in the thermoelectrochemical reaction of electrolytic aluminum.

In the construction of large-scale electrolyte shaped bricks, reinforcement can be set inside for strength configuration. To improve the overall strength of its large electrolyte shaped bricks, just like reinforced concrete masonry blocks.

When building electrolyte shaped bricks in an aluminum electrolytic cell, the gaps between the electrolyte shaped bricks can be filled with alumina powder or electrolyte covering powder.

Example 5: As shown in Figure 6, this example is the same as Example 4. It also uses electrolyte to build a solid thermal insulation layer in the thermal insulation layer at the bottom of the cathode carbon block. Powder material, after constructing a bottom thermal insulation layer, and then directly cast a layer of electrolyte-shaped hard crust thermal insulation insulation directly on the upper part of the bulk granular powder or the upper part of the interlayer steel plate with electrolyte solution. thermal layer. The cast-formed electrolyte hard crust thermal insulation layer is equivalent to the thermal insulation covering material crust layer on the upper part of the anode carbon block, which can not only play the role of heat insulation and heat preservation for the cathode carbon block, but also can prevent leakage effect.

When using the electrolyte solution to directly cast the structure in the electrolytic cell to shape the crust insulation layer, it can be carried out by block or integral casting. The electrolyte shaping crust insulation layer can be assumed to be equipped with a steel skeleton. This not only improves the overall strength of the thermal insulation layer of the electrolyte shaped crust. In addition, the service life of the cathode thermal insulation layer of the aluminum electrolytic cell will be greatly prolonged, and the construction cost of the aluminum electrolytic cell will be reduced.

After casting and condensation, thermal shrinkage cracks or masonry structural joints may occur on the electrolyte forming crust thermal insulation layer. The shrinkage joints and masonry structural joints can be filled and leveled with alumina or electrolyte powder.

During tank overhaul, these overhaul slag blocks formed of electrolyte materials can be directly used for electrolysis production and participate in thermoelectrochemical reactions without harmless treatment.

Embodiment 6: As shown in Figure 7, the purpose of the present invention is to reduce the thermal insulation layer at the bottom of the cathode of the aluminum electrolytic cell, and the generation of dangerous solid waste during the overhaul of the aluminum electrolytic cell.

The feature of this embodiment is that, in order to reduce the generation of dangerous solid waste in the cathode thermal insulation layer of the aluminum electrolytic cell, the dry anti-seepage layer of the cathode carbon block of the original aluminum electrolytic cell can be located at the bottom of the dry anti-seepage layer, or at the bottom of the dry anti-seepage layer of the cathode carbon block of the original aluminum electrolytic cell. The bottom of the breakout interlayer board adopts the method listed in the above implementation as shown in the figure to construct the thermal insulation layer structure below the dry anti-seepage material layer at the bottom of the cathode carbon block in the aluminum electrolytic cell.

The cathode thermal insulation layer of the aluminum electrolytic cell constructed in this way, when the tank is overhauled, the overhaul solid waste generated by the thermal insulation material of the bottom layer of the dry anti-leakage material of the aluminum electrolytic cell can be used without harmless treatment. Directly used in the production of aluminum electrolytic cells.

Embodiment 7: As shown in FIG. 8 , the feature of this embodiment is that, in order to reduce the generation of dangerous solid waste of the cathode thermal insulation layer of the aluminum electrolytic cell, the bottom of the cathode carbon block of the original aluminum electrolytic cell can be mixed with aluminum oxide. , Between the thermal insulation layer of the cathode carbon block of the aluminum electrolysis cell constructed by the electrolyte or the covering material, a layer of carbon thermal insulation and anti-leakage layer made of carbon paste is added. For the bottom of the heat-insulating and anti-leakage layer, the heat-insulating and heat-insulating layer structure of the lower part is constructed by using the method as enumerated in the above-mentioned implementation.

The cathode thermal insulation layer of the aluminum electrolytic cell constructed in this way, when the tank is overhauled, the overhaul solid waste formed by the thermal insulation material at the bottom of the carbon thermal insulation layer of the aluminum electrolytic cell can be treated without harmless treatment. It can be directly used in the production of aluminum electrolytic cells.

Embodiment 8: As shown in Figure 9, the feature of this embodiment is that, in order to reduce the amount of dangerous solid waste generated by the cathode thermal insulation layer of the aluminum electrolytic cell, a new aluminum electrolytic cell can be added at the bottom of the shell of the aluminum electrolytic cell. Thermal insulation warehouse.

The thermal insulation bin is a steel support structure, and a horizontal cover plate parallel to the bottom plate of the tank shell is arranged on the upper part of the steel support structure. The thermal insulation warehouse is filled with thermal insulation materials, and the horizontal cover plate not only has the function of protecting the thermal insulation materials filled in the thermal insulation warehouse from vertical extrusion, but also has the function of bearing the upper layer of thermal insulation materials. . The vertical support of the thermal insulation support structure of the thermal insulation warehouse can be constructed by channel steel or I-beam, and it is fixed on the horizontal bottom plate of the aluminum electrolytic cell steel tank shell by welding or bolting.

The thermal insulation bin arranged on the horizontal bottom plate of the steel shell of the aluminum electrolytic cell is a permanent structure, and the thermal insulation material filled inside can be adjusted according to the overall thermal conductivity of the thermal insulation layer at the bottom of the aluminum electrolytic cell. configuration.

After the construction of the thermal insulation bin at the bottom of the aluminum electrolytic cell shell is completed, the aluminum electrolytic cell cathode carbon can be formed between the upper part of the horizontal cover plate and the bottom layer of the aluminum electrolytic cell cathode carbon block using the structural methods listed in the above implementation. Thermal insulation layer on the bottom of the block.

When the aluminum electrolytic cell is overhauled, the stereotyped slag solid waste generated by the thermal insulation material on the upper part of the thermal insulation warehouse of the aluminum electrolytic cell can be directly used in the production of the aluminum electrolytic cell without harmless treatment. The heat-insulating refractory material inside the heat-insulating and heat-insulating silo located in the low-temperature zone at the bottom of the aluminum electrolytic cell is retained. Thereby, the purpose of reducing the overhaul cost of the aluminum electrolytic cell is achieved.

Claims (10)

1. a thermal insulation layer structure and construction method at the bottom of an aluminum electrolytic cell cathode, it is characterized in that: when implementing the thermal insulation layer structure to the bottom of the aluminum electrolytic cell cathode carbon block, select the electrolyte solution in the aluminum electrolytic cell molten pool, produce aluminum The liquid chemical composition system is pollution-free and can participate in the thermo-electrochemical reaction of the aluminum electrolytic cell. The alumina, electrolyte, alumina and electrolyte mixture for aluminum electrolysis production are selected as the material for constructing the thermal insulation layer at the bottom of the cathode carbon block. , as the construction material for the thermal insulation layer at the bottom of the cathode carbon block of the aluminum electrolysis cell. It is expected that when the aluminum electrolytic cell is overhauled, the formed thermal insulation layer is overhauled and the solid waste slag material can be directly applied to the production process of electrolytic aluminum without going through a harmless process. 2. according to a kind of aluminum electrolytic cell cathode bottom thermal insulation layer structure and construction method according to claim 1, it is characterized in that: when the thermal insulation layer structure is implemented to the bottom of the aluminum electrolytic cell cathode carbon block, select aluminum electrolysis production with oxidation Aluminum powder is used as the building material for constructing the thermal insulation layer between the bottom of the cathode carbon block of the aluminum electrolysis cell and the horizontal bottom of the tank shell; the thermal insulation layer at the bottom of the cathode carbon block is constructed, so that when the tank is overhauled, the After the alumina powder at the thermal insulation layer is taken out from the bottom of the aluminum electrolytic cell, it can be directly used in the production of electrolytic aluminum without undergoing harmless treatment. 3. according to a kind of aluminum electrolytic cell cathode bottom thermal insulation layer structure and construction method according to claim 1, it is characterized in that: when implementing thermal insulation layer structure to aluminum electrolytic cell cathode carbon block bottom, selects alumina and electrolyte to mix The upper covering material of the anode carbon block of the aluminum electrolytic cell is configured as the material for constructing the thermal insulation layer between the bottom of the cathode carbon block of the aluminum electrolytic cell and the horizontal bottom plate of the tank shell; Alumina and electrolyte are mixed to configure the covering material, after being taken out from the bottom of the electrolytic cell, it can be directly used in electrolytic aluminum production without harmless treatment. 4. according to a kind of aluminum electrolytic cell cathode bottom thermal insulation layer structure and construction method according to claim 1, it is characterized in that: when implementing thermal insulation layer structure to aluminum electrolytic cell cathode carbon block bottom, select aluminum electrolytic molten salt material for use , Electrolyte particle powder, as the material for constructing the thermal insulation layer at the bottom of the cathode carbon block of the aluminum electrolysis cell, to construct the thermal insulation layer at the bottom of the cathode carbon block, in order to prevent the failure of the thermal insulation layer when the tank is overhauled. After the electrolyte overhaul slag is taken out from the bottom of the electrolytic cell, it can be directly used in electrolytic aluminum production without harmless treatment. 5. a kind of aluminum electrolytic cell cathode bottom insulation layer structure and construction method according to claim 1, it is characterized in that: when implementing the thermal insulation layer structure to the aluminum electrolytic cell cathode carbon block bottom, can be inside the aluminum electrolytic cell The molten electrolyte is taken out of the electrolytic cell and cast in a shaping mold. After condensation to form a shaped masonry block, the masonry structure is built in the thermal insulation layer at the bottom of the cathode carbon block of the aluminum electrolytic cell; After the molten electrolyte in the tank is taken out from the electrolytic tank, it is directly cast into the thermal insulation layer at the bottom of the cathode carbon block of the aluminum electrolytic tank. When the tank is overhauled, the failed electrolyte shaped masonry block thermal insulation layer can be overhauled. After being taken out from the bottom of the electrolytic tank, it can be directly used for electrolytic aluminum production without harmless treatment. 6. a kind of aluminum electrolytic cell cathode bottom thermal insulation layer structure and construction method according to claim 1, it is characterized in that: at the bottom of aluminum electrolytic cell cathode carbon block implementing thermal insulation layer structure, with electrolyte casting stereotyped masonry When the shaped condensate layer is cast in the electrolytic cell and the shaped condensate layer is cast, the reinforcing connecting steel bars can be arranged in the shaped masonry block and the shaped condensation layer. 7. a kind of aluminum electrolytic cell cathode bottom insulation layer structure and construction method according to claim 1, it is characterized in that: when implementing the thermal insulation layer structure to the aluminum electrolytic cell cathode carbon block bottom, can be in the aluminum electrolytic cell cathode In the thermal insulation layer at the bottom, an interlayer steel plate is laid, so that the alumina particles, electrolyte particles, or alumina electrolyte mixture can be used in layers from the bottom of the cathode carbon block of the aluminum electrolytic cell to the bottom of the tank shell. A thermal insulation layer is constructed between the horizontal base plates. 8. The structure and construction method of a thermal insulation layer at the cathode bottom of an aluminum electrolytic cell according to claim 1, wherein: when the thermal insulation layer structure is implemented at the bottom of the cathode carbon block of the aluminum electrolytic cell, the thermal insulation can be A layer of dry anti-leakage material is laid between the upper part of the layer and the bottom of the cathode carbon block, and then on the upper part of the dry anti-leakage material layer, a steel rod group for the cathode carbon block of the masonry aluminum electrolytic cell is constructed, in order to When the tank is overhauled, the thermal insulation layer at the bottom of the dry anti-leakage material layer can be overhauled, and after being taken out from the bottom of the electrolytic tank, it can be directly used for electrolytic aluminum production without harmless treatment. 9. a kind of aluminum electrolytic cell cathode bottom thermal insulation layer structure and construction method according to claim 1, is characterized in that: when the thermal insulation layer structure is implemented to the bottom of the aluminum electrolytic cell cathode carbon block, after completing the bottom thermal insulation layer isolation After the construction of the thermal layer, a layer of insulating steel plate can be laid on the upper part of the thermal insulation layer. The upper part of the plain tamping paste layer is constructed to build the cathode carbon block steel rod group of the masonry aluminum electrolytic cell, so that when the tank is overhauled, the failed thermal insulation layer built at the bottom of the carbon tamping paste layer can be overhauled. After the bottom of the electrolytic cell is taken out, it can be directly used for electrolytic aluminum production without harmless treatment. 10. The thermal insulation layer structure and construction method at the cathode bottom of an aluminum electrolytic cell according to claim 1, characterized in that: when the thermal insulation layer structure is implemented on the bottom of the cathode carbon block of the aluminum electrolytic cell, it can be used in the original aluminum electrolytic cell. On the top of the horizontal bottom plate at the bottom of the tank shell, a thermal insulation warehouse is newly installed. The thermal insulation warehouse is a steel support structure. On the upper part of the steel support structure, a horizontal cover plate parallel to the bottom plate of the tank shell is arranged. The thermal insulation warehouse is filled with thermal insulation materials. After the construction of the thermal insulation warehouse is completed, the cathode carbon block of the aluminum electrolytic cell can be formed between the upper part of the horizontal cover plate and the bottom layer of the cathode carbon block of the aluminum electrolytic cell. In order to overhaul the aluminum electrolytic cell, the thermal insulation material on the upper part of the thermal insulation warehouse of the aluminum electrolytic cell can be overhauled, and the slag can be directly used in the aluminum electrolytic cell without harmless treatment. production.

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