A slag line structure for an aluminum alloy filtration and purification box and its preparation method

Abstract

This invention relates to a slag line structure for an aluminum alloy filter and purification box and its preparation method in the field of aluminum alloy processing technology. The invention includes an inner lining and a slag line structure. The inner lining is cast from molten silica refractory castable that is not wetted by molten aluminum. A slag line groove is pre-reserved in the slag line area of ​​the inner lining. The slag line structure matches and is located within the slag line groove. The slag line structure comprises several interlocking blocks, each made of silicon nitride-based material. A 1mm thick alumina fiber paper is placed in the joints between adjacent blocks. A 1-3mm thick alumina fiber paper is adhered to the top, bottom, and outer surfaces of the slag line structure. Corundum refractory mortar is filled in the gaps between the blocks and the slag line groove, as well as in the joints between the blocks. The slag line structure and the inner lining are firmly bonded together as a whole after high-temperature sintering. This invention is easy to manufacture, can extend the service life of the aluminum alloy filter and purification box, and improve the purification effect of molten aluminum.

Description

Technical Field

[0001] This invention belongs to the field of aluminum alloy processing technology, specifically, it relates to a slag line structure for an aluminum alloy filtration and purification box and its preparation method. Background Technology

[0002] In the aluminum alloy processing industry, molten aluminum requires purification processes, including degassing and slag removal. Materials in contact with the molten aluminum and slag are corroded by both, leading to problems such as material detachment and cracking, thus causing secondary pollution of the molten aluminum. This is particularly problematic when purifying certain special alloys (such as 5, 6, and 7 series alloys and aluminum-lithium alloys), where the slag line lining the purification equipment is severely corroded by the special alloy molten aluminum and slag. This is a problem that needs to be addressed to ensure effective aluminum purification and prevent further contamination.

[0003] Currently commonly used aluminum liquid purification equipment has an internal lining (such as...) Figure 1 The refractory materials shown are mostly made of fused silica, which has a low coefficient of thermal expansion, is not prone to cracking, and has good anti-adhesion properties. However, this material is easily corroded and detached at the slag line. Although alumina-based or silicon nitride-based materials can be used to improve corrosion resistance, these materials have a high coefficient of thermal expansion and are prone to cracking during heating, leading to molten aluminum leakage. Therefore, a new design is needed to solve this problem. Summary of the Invention

[0004] The purpose of this invention is to solve the above-mentioned technical problems and to propose a slag line structure for an aluminum alloy filtration and purification box and its preparation method.

[0005] Based on one aspect of the present invention, a slag line structure for an aluminum alloy filter purification box is proposed, comprising an inner lining and a slag line structure. The inner lining is cast using a molten silica refractory castable that is not wetted by molten aluminum. The molten silica refractory castable that is not wetted by molten aluminum is the type disclosed in patent document CN 101734928B. A slag line groove is pre-reserved in the slag line area of ​​the inner lining. The slag line structure matches and is located within the slag line groove. The slag line structure comprises several interlocking blocks, and the block assembly reduces overall stress. Each block is made of silicon nitride-based material, meeting the YBT4035-2007 standard, and exhibits excellent resistance to molten aluminum corrosion. Furthermore, 1mm thick alumina fiber paper is installed in the joint between adjacent blocks, and 1-3mm thick alumina fiber paper is pasted on the top, bottom and outer sides of the slag line structure. Corundum refractory mortar is filled in the gap between the blocks and the slag line groove, as well as the joint between each block. The slag line structure and the inner lining of the box are firmly bonded together as a whole after high-temperature sintering.

[0006] Preferably, the height of the slag line trough is 410-510 mm and the depth is 45 mm.

[0007] Preferably, the height of each block is 10mm less than the height of the slag line trough, and the thickness of each block is 40mm.

[0008] Preferably, adjacent panels are joined together by a convex-concave fit, which can improve the sealing effect between the panels.

[0009] Preferably, the alumina fiber paper is mullite alumina fiber paper, in which alumina accounts for 72-75% and silicon dioxide accounts for 25-28%, and it has good anti-corrosion properties and non-alumina properties.

[0010] Preferably, the silicon nitride-based material is a silicon nitride-bonded silicon carbide brick.

[0011] Preferably, the corundum refractory mortar is of type GN-85P or GN-90P, which is a high alumina-based rapid solidification castable. It can be used to repair existing furnace linings or cast new furnace linings. It has very good adhesion and fine particle size distribution, can bond well with dust-free refractory surfaces, and produce excellent bonding strength.

[0012] Preferably, the sintering temperature during high-temperature sintering is 600–750°C.

[0013] Based on another aspect of the present invention, a method for preparing a slag line lining structure for an aluminum alloy filtration and purification box is proposed, comprising the following steps:

[0014] S1. The inner lining of the aluminum alloy filter and purification box is made of molten silica refractory castable that is not wetted by aluminum liquid, and a slag line groove is reserved in the slag line area of ​​the inner lining, that is, within 200-300mm above and below the aluminum liquid surface.

[0015] S2. Several blocks are made of silicon nitride-based material and are spliced ​​together by convex and concave fitting to form a slag line structure. The slag line structure is matched with the slag line groove.

[0016] S3. Assemble each component sequentially into the slag line groove, and adhere 1mm thick alumina fiber paper to the joints between adjacent components. Also adhere 1-3mm thick alumina fiber paper to the top, bottom, and outer surfaces of the slag line structure. Fill the connections between components and between the slag line structure and other parts of the tank lining with alumina fiber paper. Alumina fiber paper has good elasticity and flexibility, facilitating processing and installation. Simultaneously, when the tank is hot, the alumina fiber paper reduces stress on the slag line structure, preventing gap expansion and aluminum leakage.

[0017] S4. Use corundum refractory mortar to fill the joints between adjacent blocks and other gaps between the top, bottom and outer sides of the slag line structure and the slag line groove, ensuring full filling; to ensure a tight connection between the slag line structure and the inner lining of the box.

[0018] S5. After the slag line structure and slag line trough are assembled, the inner lining of the box and the slag line structure are sintered at high temperature of 600-750℃ for 24 hours. High-temperature sintering ensures that the slag line structure and the inner lining of the box are firmly bonded together as a whole, preventing the detachment of parts and aluminum leakage.

[0019] The present invention also includes other devices, components or steps that enable its normal use, all of which are conventional means in the art. In addition, any devices, components or steps not limited in the present invention adopt the prior art in the art.

[0020] The working principle of this invention is that the slag line structure of the box body can combine the advantages of fused silica refractory material and silicon nitride bonded silicon carbide brick. The lining material has a low coefficient of thermal expansion, high crack resistance and thermal shock resistance. While ensuring the overall durability of the lining, the special slag line structure and the combination of corresponding materials effectively prevent the erosion problem of the slag line part and ensure the purification effect of aluminum liquid.

[0021] Compared with the prior art, the beneficial effects of the present invention are:

[0022] The lining and slag line structure of the box of the present invention are easy to manufacture, and can extend the service life of the aluminum alloy filter purification box and improve the purification effect of aluminum liquid. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the internal lining of a box in the prior art.

[0024] Figure 2 This is a schematic diagram of the overall structure of the slag line structure inside the box of the present invention in an embodiment.

[0025] Figure 3 This is a schematic diagram of the overall structure of the slag line structure of the present invention in an embodiment.

[0026] Figure 4 This is a schematic diagram of the structure of block one of the slag line structure of the present invention in an embodiment.

[0027] Figure 5 This is a schematic diagram of the second component of the slag line structure of the present invention in an embodiment.

[0028] Figure 6 This is a schematic diagram of the structure of block three of the slag line structure of the present invention in an embodiment.

[0029] Figure 7This is a schematic diagram of the structure of block four of the slag line structure of the present invention in an embodiment. Detailed Implementation

[0030] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0031] Example

[0032] like Figures 2-7 As shown, this embodiment proposes a slag line structure for an aluminum alloy filter purification box, including a box liner 2 and a slag line structure 1. The box liner 2 is cast using a fused silica refractory castable that is not wetted by molten aluminum. The fused silica refractory castable that is not wetted by molten aluminum is the type disclosed in the patent document with authorization announcement number CN 101734928B. A slag line groove (not shown in the figure) is reserved in the slag line area of ​​the box liner 2. The slag line structure 1 matches the slag line groove and is located within the slag line groove. The slag line structure 1 includes several interlocking blocks. Each block includes four specifications: block 11, block 212, block 313, and block 414. The slag line structure adopts a block assembly method, which reduces the overall stress. Each block is made of silicon nitride-based material, meets the YBT4035-2007 standard, and has excellent resistance to molten aluminum corrosion. Furthermore, a 1mm thick alumina fiber paper (not shown in the figure) is provided in the joint 15 between adjacent blocks. A 1-3mm thick alumina fiber paper (not shown in the figure) is pasted on the top 16, bottom 17 and outer side 18 of the slag line structure 1. Corundum refractory mortar (not shown in the figure) is filled in the gap between the block and the slag line groove and the joint between each block. The slag line structure 1 and the inner lining 2 of the box are firmly bonded together as a whole after high-temperature sintering.

[0033] Specifically, the height of the slag line trough is 410-510mm and the depth is 45mm; the height of each block is 10mm less than the height of the slag line trough, and the thickness of each block is 40mm; adjacent blocks are joined together by a convex-concave fit, which can improve the sealing effect between the blocks.

[0034] In this embodiment, the alumina fiber paper is mullite-based alumina fiber paper with an alumina content of 72-75%, which has good erosion resistance and non-stick properties. The silicon nitride-based material is silicon nitride-bonded silicon carbide brick. The corundum refractory mortar, model GN-85P, is a high alumina-based rapid-setting castable that can be used to repair existing furnace linings or cast new furnace linings. It has very good adhesion and a fine particle size distribution, can bond well with dust-free refractory surfaces, and produces excellent bonding strength.

[0035] This embodiment also proposes a method for preparing a slag-lined internal lining structure for an aluminum alloy filtration and purification box, comprising the following steps:

[0036] S1. The inner lining 2 of the aluminum alloy filter and purification box is cast with molten quartz refractory castable that is not wetted by aluminum liquid, and a slag line groove is reserved in the slag line area of ​​the inner lining 2, that is, within 200-300mm above and below the aluminum liquid surface.

[0037] S2. Several modules are made of silicon nitride-based material (the structure of each module is as follows) Figures 4-7 As shown), several blocks are joined together by a convex-concave fit to form a slag line structure 1, which is matched with the slag line groove.

[0038] S3. Assemble each component into the slag line groove sequentially, and paste 1mm thick alumina fiber paper into the joints of adjacent components. Also paste 1-3mm thick alumina fiber paper onto the top 16, bottom 17, and outer surface 18 of the slag line structure 1. Alumina fiber paper is used to fill the connections between components and between the slag line structure 1 and other parts of the inner lining 2 of the box. Alumina fiber paper has good elasticity and flexibility, facilitating processing and installation. Simultaneously, when the box is hot, the alumina fiber paper can reduce the stress on the slag line structure 1, preventing gap expansion and aluminum leakage.

[0039] S4. Use corundum refractory mortar to fill the joints 15 between adjacent blocks and the other gaps between the top 16, bottom 17 and outer side 18 of the slag line structure 1 and the slag line groove, ensuring full filling; to ensure a tight connection between the slag line structure 1 and the inner lining 2 of the box.

[0040] S5. After the slag line structure 1 and the slag line trough are assembled, the inner lining 2 and the slag line structure 1 of the box are sintered at high temperature of 600-750℃ for 24 hours. Through high-temperature sintering, the slag line structure 1 and the inner lining 2 of the box can be firmly bonded to become a whole, avoiding the occurrence of piece detachment and aluminum leakage.

[0041] The working principle of this invention is that the slag line structure of the box body can combine the advantages of fused silica refractory material and silicon nitride bonded silicon carbide brick. The lining material has a low coefficient of thermal expansion, high crack resistance and thermal shock resistance. While ensuring the overall durability of the lining, the combination of special slag line structure 1 and corresponding materials effectively prevents the erosion problem of the slag line part and ensures the purification effect of aluminum liquid.

[0042] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A slag line structure for an aluminum alloy filter purification tank liner, comprising a tank liner and a slag line structure, characterized by: The inner lining of the box is made of molten silica refractory castable that is not wetted by molten aluminum, and a slag line groove is reserved in the slag line area of ​​the inner lining. The slag line structure matches the slag line groove and is set in the slag line groove. The slag line structure includes several interlocking blocks. Each block is made of silicon nitride-based material, and a 1mm thick alumina fiber paper is placed in the joint between adjacent blocks. A 1-3mm thick alumina fiber paper is pasted on the top, bottom, and outer sides of the slag line structure. The gaps between the blocks and the slag line groove, as well as the joints between the blocks, are filled with corundum refractory mortar. The slag line structure and the inner lining of the box are firmly bonded to a whole after high-temperature sintering. The high-temperature sintering temperature is 600-750℃, and the holding time is 24 hours.

2. The slag line structure inside the aluminum alloy filtration and purification box according to claim 1, characterized in that: The height of the slag line trough is 410~510mm and the depth is 45mm.

3. The slag line structure inside the aluminum alloy filtration and purification box according to claim 2, characterized in that: The height of each block is 10mm less than the height of the slag line trough, and the thickness of each block is 40mm.

4. The slag line lining structure inside the aluminum alloy filtration and purification box according to claim 1, characterized in that: Adjacent panels are joined together using a convex-concave fit.

5. The slag line structure inside the aluminum alloy filtration and purification box according to claim 1, characterized in that: The alumina fiber paper is a mullite-based alumina fiber paper containing 72-75% alumina.

6. The slag line lining structure inside the aluminum alloy filtration and purification box according to claim 1, characterized in that: The silicon nitride-based material is a silicon nitride-bonded silicon carbide brick.

7. The slag line lining structure inside the aluminum alloy filtration and purification box according to claim 1, characterized in that: The corundum refractory mortar is of model GN-85P or GN-90P.

8. A method for preparing a slag line structure for an aluminum alloy filter and purification box based on any one of claims 1 to 7, characterized in that, Includes the following steps: S1. The inner lining of the aluminum alloy filter and purification box is made of molten silica refractory castable that is not wetted by aluminum liquid, and a slag line groove is reserved in the slag line area of ​​the inner lining, that is, within 200~300mm above and below the aluminum liquid surface. S2. Several blocks are made of silicon nitride-based material and are spliced ​​together by convex and concave fitting to form a slag line structure. The slag line structure is matched with the slag line groove. S3. Assemble each piece into the slag line groove in sequence, and paste 1mm thick alumina fiber paper in the joint of adjacent pieces, and paste 1~3mm thick alumina fiber paper on the top, bottom and outer sides of the slag line structure. S4. Use corundum refractory mortar to fill the joints between adjacent blocks and other gaps between the top, bottom and outer sides of the slag line structure and the slag line groove, ensuring full filling. S5. After the slag line structure and slag line trough are assembled, the inner lining of the box and the slag line structure are sintered at high temperature of 600~750℃ and kept at that temperature for 24 hours.

Images