Self-stabilizing lost foam and method for slotting prebaked anodes using the lost foam

Abstract

The present invention discloses a self-stabilizing lost foam and a method for slotting a pre-baked anode using the lost foam. The lost foam comprises a plurality of parallel main plates and a plurality of supporting ribs arranged between the main plates. The main plates and the supporting ribs are made of a material that burns and decomposes and disappears in a high-temperature environment. The lost foam can be stably supported by itself in a forming mold frame with a smooth inner wall. The method comprises placing the lost foam in a close fit at the bottom of the forming mold frame of a forming machine; adding anode paste and starting vibration molding. During the high-temperature roasting process of the green carbon block with the lost foam, the lost foam is consumed by combustion and decomposition. The green carbon block has high hardness under the high temperature of roasting and no longer deforms. After the burning is completed, the space originally occupied by the lost foam becomes the shape and space required for the slotting of the cooked anode carbon block. The residual ash after the high-temperature roasting of the lost foam can be cleaned by scraping and blowing the residual ash in the grooves during the process of cleaning the surface of the cooked anode carbon block and the bowl hole after roasting.

Description

Technical Field

[0001] The invention belongs to the technical field of prebaked anode slotting, and in particular relates to a self-stabilizing lost foam and a method for slotting a prebaked anode using the lost foam. Background Art

[0002] Prebaked anode grooving is a popular anode use process for electrolysis in recent years. It refers to the process of opening a full-length groove of a certain depth at the bottom of the prebaked anode carbon block to increase the exhaust performance of the bottom surface of the anode and accelerate the anode heating rate. It can play a positive role in energy saving and consumption reduction in the electrolysis process and production stability.

[0003] There are currently two methods for slotting anode carbon blocks in the industry. One is to saw the bottom of the finished carbon block after roasting to create the slots; the other is to use a forming mold to pre-form the grooves during the green anode forming stage before roasting. Both methods have certain disadvantages, which are analyzed as follows:

[0004] The disadvantages of sawing the bottom of the finished cooked carbon block after roasting are: 1) Direct cutting with a hard wheel saw can easily cause cracking and damage to the carbon block due to its high hardness and density. It is a hard and brittle material. 2) A large amount of dust is generated during the sawing process, which is very noisy and seriously pollutes the environment. 3) The wheel saw is very worn. Low-quality saw blades need to be replaced in a few days. Special hard saw blades are expensive and can only be replaced after one or two months of use. The maintenance workload is huge. The sawing equipment is large in size and slow in processing speed. It is generally necessary to configure a variety of conveying equipment upstream and downstream to transport the carbon blocks, which occupies a large amount of production land. 4) The sawing length of a single groove reaches The cutting depth is more than 1.5 meters, the cutting depth is 0.3 to 0.5 meters, and the cutting width is 10 to 25 mm. Generally, two grooves are required for each anode carbon block. Based on the anode density of 1.58 g / cc, the weight of the fragments cut off during the grooving exceeds 20 kg, which means that more than 20 kg of high-quality anode materials will be wasted, and the loss ratio will reach more than 2% of the production capacity; 5) Sawing equipment, conveying equipment, dust collection equipment, etc. constitute a complex electromechanical system, which requires huge investment. The operation energy consumption of high-power circular saws, large-volume dust collection equipment, etc. is high. The operation and maintenance of the grooving system will generate a large amount of expensive consumables, energy consumption, labor, material transportation, safety protection, environmental governance, material waste, capital occupation and other high operation and maintenance costs.

[0005] In order to circumvent the drawbacks of the sawing and grooving method of the cooked anode carbon blocks after roasting, there is also a method of using a forming mold to prefabricate grooves during the raw anode forming stage, but there are also the following defects: 1) The forming mold needs to be modified, and vertical prefabricated mold pieces are added to the bottom plate of the forming mold according to the required groove size. The forming and demoulding pushing method of the carbon block is changed, and the carbon block can only be pushed out longitudinally from the end face along the direction of the groove, and cannot be pushed horizontally. It is necessary to make fundamental adjustments to the layout and action sequence of the forming machine, resulting in huge investment in the modification of the forming machine; 2) The newly formed raw anode carbon blocks are soft and sticky, and are easy to adhere to the mold piece. When demoulding, it is very easy to cause the carbon block grooves on both sides to be chipped or broken. The mold piece size and shape are fixed, and the groove size is not easy to adjust; 3) The added slotted prefabricated mold piece must be a whole plate without holes, otherwise it cannot be demoulded, which is equivalent to the overall mold A full-length partition is added to block the extrusion fluidity of the anode paste, resulting in inconsistent density on both sides of the groove at the bottom of the anode carbon block, seriously affecting the quality of the anode; 4) During the extrusion vibration molding process, since it is difficult to ensure that the paste is absolutely uniform on both sides of the mold, lateral pressure will be generated on the mold, causing the mold to bend and deform. Once the mold is bent, the carbon block will be unable to be demolded; 5) After the molding, the asphalt adhesive has not yet completely solidified in the raw anode, and the carbon block will undergo a certain amount of sinking deformation under its own weight. The prefabricated groove is a weak link in deformation, and there is a possibility that the deformation of the two sides of the groove will be closer, the groove width will be narrowed, or even disappear; 6) During the roasting process of the anode carbon block with grooves, a large amount of filler will enter the groove space. After roasting, the filler will be sintered and adhered to the groove, blocking the groove and making it difficult to clean, seriously affecting the purity and quality of the carbon block.

[0006] The process for forming grooves on the bottom or side of anode carbon blocks for aluminum electrolysis, with publication number CN1887557A, describes a main technical means of changing the processing object from cooked blocks to green blocks, and changing the processing means from mechanical processing to mold forming, without affecting the quality and performance of the product. Under vibration pressure conditions, the blocks are shaped into pre-baked anode green blocks with grooves on the bottom or side, and the method mainly adopts a strip-shaped vertical uniform paste distribution method to maintain the fluidity of the paste; a secondary cooling method is adopted to meet the requirements of the demoulding action for the solidification state of the paste. This kind of slotting process is easy and convenient to demould, energy-saving and consumption-reducing, with high output and high efficiency. The material of the slotting template of this process can be a metal material or a non-metallic flammable material, such as wood board, fiberboard, particleboard and other resin materials. The slotting template of non-metallic material can be directly sent to high-temperature roasting for decomposition and then slag cleaning without demoulding. This invention uses combustible materials as templates and directly removes them through combustion. However, this patented technology requires the modification of the molding mold box and the opening of slots on the side walls of the mold box. The template cannot stabilize and fix its position by itself. Secondly, there is a seam on the side of the mold box (through the slot), which will seriously affect the strength of the mold box. During vibration extrusion, there is a large outward extrusion force inside the mold box, which will cause the mold box to deform and crack from the gap. Finally, the template is stuck on the side wall of the mold box. When the mold box is lifted to demold, the template will rise with the mold box, and the template is embedded in the charcoal block. In fact, the mold box and the charcoal block are stuck by the template and cannot be demolded.

[0007] In summary, the current pre-baked anode grooving process has many defects, resulting in a lower qualified rate of finished products, increased production costs, and great environmental and safety risks. Summary of the Invention

[0008] In order to solve the above problems, the present invention aims to provide a self-stabilizing lost foam and a method for slotting a prebaked anode using the lost foam.

[0009] In order to achieve the above-mentioned purpose, the present invention adopts the following technical solution: a self-stabilizing lost foam for producing pre-baked anode carbon blocks with grooves, comprising a plurality of side-by-side main boards and a plurality of supporting ribs arranged between the main boards, wherein the main boards and the supporting ribs are made of materials that burn and decompose and disappear in a high-temperature environment, and the lost foam can stably support itself in a forming mold frame with a smooth inner wall.

[0010] The supporting ribs are spliced ​​at the outer ends of the sides between the parallel main boards by bonding or mortise and tenon joints. The length of the main board is consistent with the length of the inner end of the forming mold frame, and the length of the supporting ribs is consistent with the width of the inner end of the forming mold frame.

[0011] The number, thickness and shape of the main board correspond to the number, thickness and shape of the grooves required for the anode carbon block. The inner wall surface of the forming mold frame forms a rectangular space. The main board stands upright in the rectangular space and its two ends are against a pair of opposite inner sides of the forming mold frame. The supporting ribs are installed between the two sides of the main board and the other pair of opposite inner sides of the forming mold frame, and are against the other pair of opposite inner sides of the main board and the forming mold frame; the height of the main board is less than the height of the rectangular space, and two or more supporting ribs are configured as needed, and the arrangement is parallel to each other or diagonally cross-arranged.

[0012] The mainboard is a whole panel or a structure with holes opened on the panel. The size, shape, number and position of the holes are determined according to the process requirements; the bottom and side edges of the mainboard are straight edges, and the top edge includes straight edges, beveled edges, Y-shaped edges, and curved edges but is not limited to the above shapes.

[0013] The number and placement of the support ribs are selected according to the needs of the main board and the process requirements to ensure that the support ribs are at the outer surface end of the anode carbon block after forming. In addition to the support ribs (2), a transverse partition made of the same material as the main board and penetrating the bottom surface can be added between the main boards as needed.

[0014] The lost foam is made of wood material, and can also be made of non-metallic organic materials containing elements such as C, H, N, O, which can be burned into gaseous oxides at high temperatures and are non-toxic and free of impurities.

[0015] A method for grooving using a self-stabilizing lost foam foam comprises the following steps:

[0016] Step 1: Place the lost foam on the bottom of the molding mold frame of the molding machine;

[0017] Step 2: Add anode paste and start vibration molding. After the paste fills the molding machine mold frame, it wraps and covers the lost foam in a stable position, and then undergoes overall vibration extrusion molding. The lost foam is completely embedded in the carbon block during the carbon block molding process.

[0018] Step 3: During the high-temperature roasting process of the green charcoal block with the lost foam, the lost foam is burned and decomposed and consumed. The green charcoal block has high hardness under the high temperature of roasting and no longer deforms;

[0019] Step 4: After the combustion is completed, the space originally occupied by the lost foam becomes the shape and space required for the grooves of the cooked anode carbon block. The residual ash after the lost foam is roasted at high temperature can be cleaned by scraping and blowing the residual ash in the grooves during the process of cleaning the surface of the cooked anode carbon block and the bowl hole after roasting.

[0020] After the supporting ribs disappear due to high-temperature combustion, shallow grooves are left on the side surfaces of the finished anode carbon blocks, which do not affect the placement, transportation and electrolytic use of the carbon blocks.

[0021] In step 1, the length and width of the lost foam allow the lost foam to rest against the inner walls of the molding mold frame, so that the mainboard maintains a substantially unchanged relative position and angle during the paste addition and molding process.

[0022] In step 2, the holes in the lost foam allow the anode paste to be connected, thus generating local connections in the grooves of the anode carbon block before the finished product.

[0023] Compared with the prior art, the present invention has the following advantages:

[0024] 1. The lost foam structure of the present invention saves costs and simplifies the process. No modifications, such as through-holes or slots, are required in the mold box or mold frame of the existing carbon block forming machine. The groove structure of the carbon block can be determined by the shape of the lost foam. The lost foam is stably supported within the smooth inner walls of the mold box or mold frame by its own structure, preventing tipping or misalignment. Reliable prebaked anode carbon block slotting can be achieved with this method at a low cost.

[0025] 2. The material of the lost foam of the present invention can burn and disappear at high temperature. Its main board and supporting structure are made of materials that can burn and decompose and disappear in a high temperature environment. The lost foam does not need to be removed during the slotting process. The green carbon block with the lost foam is burned and decomposed during the high-temperature roasting process of the roasting process. The carbon block has a high hardness under the high temperature of roasting and will no longer deform. The space originally occupied by the lost foam becomes the shape and space required for slotting of the cooked anode carbon block.

[0026] 3. Holes can also be opened on the main board of the present invention to enable the paste on both sides of the main board to flow evenly. The holes will generate local connections in the grooves of the finished anode carbon block. These connections will not affect the exhaust function of the slotted carbon block in the electrolytic cell. On the contrary, they can enhance the structural strength of the slotted carbon block, improve the uniformity of the current distribution inside the carbon block by connecting both sides of the groove, and play a good inhibitory role in reducing adverse phenomena such as slag falling, local block falling, and bulging on the bottom surface of the anode. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the specific embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0028] Figure 1 Schematic diagram of the lost foam in the present invention;

[0029] Figure 2 Schematic diagram of lost foam molding in green carbon blocks in the present invention;

[0030] Figure 3 This is a schematic diagram of the lost foam disappearing after firing and the cooked carbon block with grooves in the present invention;

[0031] In the figure, 1-main board; 2-support ribs; 3-molding mold frame; 4-holes; 5-anode carbon block. DETAILED DESCRIPTION

[0032] The present invention is further described below with reference to the accompanying drawings and specific embodiments. However, it should not be understood that the scope of the subject matter described in the present invention is limited to the following embodiments. Without departing from the above technical ideas of the present invention, various modifications, substitutions and changes made according to common technical knowledge and customary means in the field are included in the scope of the present invention.

[0033] Reference Figure 1 All components of the self-stabilizing lost foam used to produce grooved prebaked anode carbon blocks are made of materials that burn, decompose, and disappear in high-temperature environments. The lost foam is a simple, easily constructed frame structure consisting primarily of a main plate 1 and supporting ribs 2. The frame's length and width are precisely aligned with the inner walls of the forming mold frame 3, ensuring that the main plate 1 maintains a relatively constant relative position and angle during the paste feeding and molding process. The main plate 1 and supporting ribs 2 are bonded using organic adhesive, or alternatively, mortise and tenon joints to maintain the overall shape and stability of the lost foam frame.

[0034] The main plate 1 can be a solid panel, or it can be provided with holes 4 at the bottom as needed. These holes 4 allow the anode paste on both sides of the main plate 1 to flow freely, ensuring fluidity during the vibration extrusion process and ultimately ensuring uniform density of the carbon blocks on both sides of the grooves. The size, shape, number, and specific location of the holes 4 can be determined based on process requirements. The reserved holes 4 create local connections within the grooves of the finished anode carbon block 5. These connections do not affect the venting function of the slotted carbon block in the electrolytic cell. Instead, they strengthen the structural strength of the slotted carbon block, connect the two sides of the grooves, and improve the uniformity of current distribution within the carbon block. This effectively prevents adverse phenomena such as slag shedding, localized block shedding, and bulging on the anode bottom surface. The number, thickness, and shape of the main plate in each set of lost foam molds correspond to the number, thickness, and shape of the slots required in the anode carbon block 5. The bottom and side edges of the main plate 1 are generally straight, while the top edge can be flat, beveled, Y-shaped, curved, or other shapes. The main plate shape is determined based on the specific process requirements of each factory and can be changed at any time.

[0035] The number and placement of the support ribs 2 are adjusted based on the need to support and secure the main plate 1 and the acceptable location of the shallow grooves left on the side surfaces of the carbon block after the support ribs 2 burn out. However, they must be placed on the edge of the lost foam frame (i.e., on the outer surface of the carbon block after molding) to facilitate combustion and decomposition, and to prevent the formation of internal holes that affect the carbon block's density and conductivity. Furthermore, between the main plates 1, in addition to the support ribs 2, cross-sections made of the same material as the main plates 1 can be added, extending through the bottom surface, based on the specific requirements of the carbon block's groove shape and the need to enhance the stability of the lost foam. The inner wall of the molding die frame 3 forms a rectangular space. The main plate 1 stands upright within the rectangular space, with its ends resting against a pair of opposing inner surfaces of the molding die frame 3. The support ribs 2 are installed between the two sides of the main plate 1 and the other pair of opposing inner surfaces of the molding die frame 3, resting against the other pair of opposing inner surfaces of the main plate 1 and the molding die frame 3. The height of the main plate 1 is less than the height of the rectangular space. Two or more support ribs 2 are configured as needed, arranged in parallel or in a diagonally cross-bracing arrangement.

[0036] Lost foam is made of wood, but can also be made of non-toxic, impurity-free, non-metallic organic materials containing elements such as C, H, N, and O that burn into gaseous oxides at high temperatures. The material can be mixed with a certain amount of organic glue that is free of metals and other impurities, does not contaminate the carbon block, and can also burn and decompose in a high-temperature environment. Extruded into a high-density artificial board, it possesses a certain strength and density, capable of densely filling the raw anode carbon block while maintaining its shape and thickness, thus maintaining the shape of the anode carbon block's grooves. The wood material will fully burn and decompose within a roasting cycle of more than 20 hours and at temperatures above 1100°C. The remaining ash remains in the groove space, blocking the ingress of filler and absorbing the volatile components of the asphalt tar to prevent adhesion.

[0037] Reference Figure 2 and Figure 3 , a method for slotting using a self-stabilizing lost foam:

[0038] Step 1: Before each green carbon block is formed, the lost foam is placed directly on the bottom of the forming mold frame 3 of the forming machine. The length and width of the lost foam allow the lost foam to rest against the inner wall of the forming mold frame 3. The lost foam is self-supporting and firmly positioned in the forming mold frame 5. When the anode paste is added and vibration molding begins, it will not fall over or be misaligned, thus ensuring that the groove shape and position of the carbon block after molding are qualified.

[0039] Step 2: Add anode paste and start vibration molding. After the paste fills the molding machine mold frame, it wraps and covers the lost foam in a stable position, and then is vibrated and extruded as a whole. The lost foam is completely embedded in the carbon block during the carbon block molding process and does not need to be demolded.

[0040] Step 3: High temperature roasting. During the high temperature roasting process of the green carbon block with lost foam, the lost foam is burned, decomposed and consumed. The carbon block has a high hardness under the high temperature of roasting and will no longer deform. The space originally occupied by the lost foam becomes the shape and space required for the slotting of the cooked anode carbon block.

[0041] Step 4: The residual ash after the lost foam is roasted at high temperature can be cleaned by simply scraping and blowing the residual ash in the groove during the process of cleaning the surface of the cooked anode carbon block and the bowl hole after roasting.

[0042] After the support ribs 2 disappear due to high-temperature combustion, shallow grooves will be left on the side surfaces of the finished anode carbon blocks, which will not affect the placement, transportation and electrolytic use of the carbon blocks.

[0043] Example 1: Anode carbon blocks to be manufactured are 1700 mm long, 660 mm wide, 635 mm high, and weigh 1.03 tons. Annual production is approximately 300,000 blocks. Two longitudinally extending chute grooves are required at the bottom of the carbon block. One end of the chute is low (300 mm above the bottom surface) and the other end is high (500 mm above the bottom surface). The two grooves are centered, parallel, and 300 mm apart. Each groove is 10 mm wide.

[0044] This EPC process uses a main plate (1) whose shape and dimensions match the chute requirements of the prefabricated anode carbon blocks (5). Support ribs (2) are mortise-and-tenoned at the upper and lower ends of the two main plates (1). Wooden EPCs are added to each carbon block during molding. After firing, the EPCs burn out, leaving the block grooves intact. Each EPC weighs approximately 15 kg and is made from a variety of woods. The procurement and processing cost is approximately 30 yuan per set, resulting in an annual production cost of 9 million yuan for 300,000 sets. Six operators working in three shifts to place the EPCs are added to the molding process, resulting in a labor cost of approximately 600,000 yuan. No additional processing equipment is required, resulting in zero energy consumption and environmental pollution.

[0045] Before adopting this technology, the bottoms of the finished charcoal blocks after roasting were notched by sawing. This resulted in a breakage rate of over 5% due to cracks, chipping, and other damage. The charcoal warehouse is equipped with three circular saw notching machines, along with upstream and downstream conveyors and a high-volume dust removal system. The notching equipment occupies a total area of ​​1,200 square meters and has a total installed power of 550 kW. The investment in the notching system equipment exceeded 10 million yuan, with approximately 4 million yuan invested in auxiliary systems such as civil engineering, power, ventilation, and cooling. According to statistics, the annual operation and maintenance costs of the sawing and grooving system, including maintenance, repairs, wearing parts, and spare parts, are more than 2 million yuan; based on the estimated value reduction of 2,000 yuan / ton for qualified products and scrap materials, the annual loss caused by the 5% scrap rate is as high as more than 30 million yuan; the sawing loss is about 22 kg per piece, and the annual output of 300,000 pieces is a total loss of 6,600 tons. Based on the same estimated value reduction of 2,000 yuan / ton for reuse, the annual loss cost is 13 million yuan; the operating electricity consumption is 2 million yuan; there are 6 people in the grooving system, and 20 workers are deployed in three shifts plus maintenance workers, with an annual labor cost of 2 million yuan. The total annual operating expenses of the factory's sawing and grooving system exceed 50 million yuan.

[0046] After adopting this invention, the operating cost of this technology is less than 10 million yuan and only 6 workers are needed. Compared with the operating cost of the previous sawing and grooving method, it saves 40 million yuan and 14 employees' human resources each year, and there are no environmental or safety hazards.

[0047] Although the lost foam molds may experience minor deformation, breakage, displacement, and tilt during the molding process, resulting in slight deviations in the groove shape of a small number of finished carbon blocks, actual use in electrolytic aluminum plants has shown that even with these minor groove shape deviations, good exhaust and temperature-raising effects can still be achieved, with little impact on their use in electrolytic cells. Furthermore, after the green anode is formed, the dense filling of the lost foam mold acts as a skeleton within the green anode carbon blocks, effectively suppressing sinking and deformation.

[0048] Example 2: An anode carbon factory has an annual production capacity of 250,000 tons and an annual output value of approximately 1.2 billion yuan. The anode carbon blocks manufactured are 1650 mm in length, 650 mm in width, 610 mm in height, and weigh 0.99 tons. About 250,000 carbon blocks are produced each year. Originally, the product was not slotted, but due to market customer needs, 200,000 tons of products will need to be converted to slotted carbon blocks. The bottom of the slotted carbon block needs to have two longitudinally long inclined grooves, one end of the inclined groove is low (300 mm above the bottom surface) and the other end is high (450 mm above the bottom surface). The two grooves are parallel and centered, with a spacing of 280 mm, and each groove is 15 mm wide. The factory hopes to avoid the high damage and loss rate of the roasting and sawing method, and there is no space to add slotting equipment after the roasting process. Therefore, it plans to use the solution of prefabricating grooves in the forming mold during the raw anode forming stage for transformation.

[0049] During the renovation scheme design phase, the following problems arose:

[0050] First, the production load on the original three molding machines was roughly evenly distributed. However, after the product change, 200,000 tons required slotting, while only 50,000 tons remained unslotted. If all three molding machines were to change their molds, they would be unable to produce the original unslotted product. If only two of the molds were changed, the load on these two molding machines would be too high, making it impossible to achieve the required 20-ton production capacity. The only option was to have both new and old molds for all three molding machines, switching between them as needed. This would significantly increase production complexity and severely impact the equipment's continuous operation efficiency.

[0051] Secondly, the original molding machines all had a fixed slide, pushing out carbon blocks horizontally. Adding a longitudinally slotted die at the bottom would require a longitudinal push-out system from the end. This would require changes to the position, length, and direction of the conveyor receiving the carbon blocks, and the spacing between the molding machines would also need to be increased. This would also require significant changes to the process configuration of upstream equipment, such as the paste conveyor, throughout the molding process, as well as to the plant structure. The design institute estimated that the investment in renovating the molding system would exceed 20 million yuan.

[0052] Third, a large amount of firmly bonded filling coke in the grooves of the charcoal blocks after roasting is difficult to clean, and at least two wheel saw cleaning machines need to be added for cleaning by sawing. The land occupation, investment, energy consumption, and labor costs are almost the same as the sawing and grooving method at the bottom of the finished cooked charcoal blocks after roasting.

[0053] Through the technical and economic analysis of the design institute, it was found that similar processes in the industry have a high failure rate due to demolding damage rate and baking deformation. The comprehensive calculation result is that the transformation investment is 20 million yuan and the annual operating cost is 35 million yuan. The transformation project cycle is at least 6 months, and these 6 months will seriously affect production. At least 3 months of production will be required to stop production, which will cause extremely high losses from production stoppage and production reduction.

[0054] The factory finally decided to adopt the technology of the present invention without making any changes to the equipment configuration, increasing any investment, or stopping or reducing production. It only purchased lost foam in batches and put it into use immediately, thus completing the product transformation.

[0055] Each charcoal block is formed by adding a wooden lost foam. After firing, the grooves are perfectly shaped. Each lost foam weighs approximately 20kg and is made from a variety of woods. The procurement and processing cost is approximately 35 yuan per set, and the annual production of 200,000 sets costs 7 million yuan. Six operators working in three shifts to place the lost foam in the forming process have been added, resulting in a labor cost of approximately 600,000 yuan.

[0056] The annual operating cost of the technology in this invention is less than 8 million yuan in the factory, and only 6 workers are employed. Compared with the investment and operating budget of the previous molding transformation and sawing and cleaning methods, it saves a lot of money, costs and human resources, and there is no need to stop or reduce production, and there are no environmental or safety risks.

[0057] The above describes in detail the self-stabilizing lost foam foam and the method for slotting prebaked anodes using the same, provided by the present invention. Specific examples are used herein to illustrate the structure and operating principles of the present invention. The above embodiments are intended only to facilitate understanding of the method and core concepts of the present invention. It should be noted that those skilled in the art will be able to make various improvements and modifications to the present invention without departing from the principles of the present invention, and such improvements and modifications fall within the scope of protection of the claims.

Claims

1. A self-stabilizing lost foam for producing prebaked anode carbon blocks with grooves, characterized by: The invention comprises a plurality of main boards (1) arranged side by side and a plurality of supporting ribs (2) arranged between the main boards (1), wherein the main boards (1) and the supporting ribs (2) are both made of a material that burns and decomposes and disappears in a high-temperature environment, and the lost foam can be stably supported by itself in a forming mold frame (3) with a smooth inner wall, and the length and width of the lost foam enable the lost foam to abut against the inner wall of the forming mold frame (3); The support ribs (2) are spliced ​​at the outer ends of the sides between the parallel main boards (1) by bonding or mortise and tenon joints. The length of the main board (1) is consistent with the length of the inner end of the forming mold frame (3). The length of the support ribs (2) is consistent with the width of the inner end of the forming mold frame (3). The number and placement of the support ribs (2) are selected according to the needs of the main board (1) and the process requirements to ensure that the support ribs (2) are at the outer surface end of the anode carbon block (5) after forming. The inner wall surface of the forming mold frame (3) forms a rectangular space, the main board (1) stands upright in the rectangular space and its two ends abut against a pair of opposite inner side surfaces of the forming mold frame (3), the supporting ribs (2) are installed between the two sides of the main board (1) and the other pair of opposite inner side surfaces of the forming mold frame (3), abutting against the other pair of opposite inner side surfaces of the main board (1) and the forming mold frame (3), and the supporting ribs (2) are configured as needed in two or more pieces, and are arranged in parallel or in a diagonally cross arrangement.

2. The self-stabilizing lost foam for producing prebaked anode carbon blocks with grooves according to claim 1, characterized in that: The number, thickness and shape of the main board (1) correspond to the number, thickness and shape of the grooves required for the anode carbon block (5); the height of the main board (1) is less than the height of the rectangular parallelepiped space.

3. The self-stabilizing lost foam for producing prebaked anode carbon blocks with grooves according to claim 1, characterized in that: The main board (1) is a whole panel or a structure with holes (4) opened on the panel, and the size, shape, number and position of the holes (4) are determined according to process requirements; the bottom edge and side edges of the main board (1) are straight edges, and the top edge includes a straight edge, a bevel edge, a Y-shaped edge, and an arc edge but is not limited to the above shapes.

4. The self-stabilizing lost foam for producing prebaked anode carbon blocks with grooves according to claim 1, characterized in that: Between the main boards (1), in addition to being supported by the supporting ribs (2), a transverse partition made of the same material as the main boards (1) is added as needed and passes through the bottom surface.

5. The self-stabilizing lost foam for producing prebaked anode carbon blocks with grooves according to claim 1, characterized in that: The lost foam is made of wood.

6. The self-stabilizing lost foam for producing prebaked anode carbon blocks with grooves according to claim 1, characterized in that: The lost foam is made of non-metallic organic materials containing C, H, N, and O elements, which can be burned into gaseous oxides at high temperatures and are non-toxic and free of impurities.

7. A method for slotting a prebaked anode using the self-stabilizing lost foam foam for slotting a prebaked anode according to any one of claims 1 to 6, characterized in that: The following steps are involved: Step 1: Place the lost foam on the bottom of the molding mold frame (3) of the molding machine; Step 2: Add anode paste and start vibration molding. After the paste fills the molding die frame (3), it wraps and covers the lost foam in a stable position, and then undergoes overall vibration extrusion molding. The lost foam is completely embedded in the carbon block during the carbon block molding process. Step 3: During the high-temperature roasting process of the green charcoal block with the lost foam, the lost foam is burned and decomposed and consumed. The green charcoal block has high hardness under the high temperature of roasting and no longer deforms; Step 4: After the burning is completed, the space originally occupied by the lost foam becomes the shape and space required for the grooves of the cooked anode carbon block (5). The residual ash after the lost foam is roasted at high temperature can be cleaned by scraping and blowing the residual ash in the grooves during the process of cleaning the surface and bowl hole of the cooked anode carbon block (5) after roasting.

8. The method for grooving a self-stabilizing lost foam foam according to claim 7, characterized in that: After the support ribs (2) disappear due to high-temperature combustion, shallow grooves are left on the side surfaces of the finished anode carbon block (5), which do not affect the placement, transportation and electrolytic use of the carbon block.

9. The method for grooving a self-stabilizing lost foam foam according to claim 7, characterized in that: In step 1, the length and width of the lost foam enable the lost foam to abut against the inner walls of the molding mold frame (3) so that the mainboard (1) maintains a constant relative position and angle during the paste feeding and molding process.

10. The method for grooving a self-stabilizing lost foam foam according to claim 7, characterized in that: In step 2, the holes (4) of the lost foam allow the anode paste to be connected, thereby generating a local connection in the grooves of the anode carbon block (5) before the finished product.

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