Electric arc furnace prefabricated furnace cover for casting fused alumina zirconia refractory bricks and preparation method of electric arc furnace prefabricated furnace cover

Abstract

The invention discloses an electric arc furnace prefabricated furnace cover for casting fused alumina zirconia refractory bricks and a preparation method of the electric arc furnace prefabricated furnace cover, and relates to the technical field of refractory material manufacturing. The brick comprises the following components in percentage by weight: 38 to 42 percent of waste sintered zircon brick, 54 to 58 percent of alpha-beta corundum waste, 3.5 to 4.2 percent of aluminum dihydrogen phosphate, 1.2 to 1.8 percent of high-alumina cement and 0.5 to 1 percent of nano aluminum oxide micro powder. By using the waste refractory material as the main raw material, the thermal insulation and energy saving effects are realized, the material liquid melting quality and the product quality are improved, the production cost can be reduced, and meanwhile, the influence of industrial waste on the environment is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of refractory material manufacturing, in particular to a prefabricated furnace cover for an electric arc furnace used for melting and casting zirconium corundum refractory bricks and a preparation method thereof. Background Art

[0002] The existing electric arc furnace structure consists of three main parts: a water-circulating furnace cover, a central furnace, and a furnace body. The furnace cover utilizes a hollow, water-circulating cooling structure welded from steel plates. While this effectively reduces the temperature, given furnace temperatures exceeding 1500°C and the melt temperature of the liquid required to reach over 2000°C, the water-circulating furnace cover removes a significant amount of heat, negatively impacting both the melt efficiency and power consumption.

[0003] The main structure of an existing electric arc furnace consists of three core components: a water-circulating cooling furnace cover, an intermediate transition section furnace shell, and a basic furnace body. The water-circulating furnace cover is welded using double-layer steel plates, forming a sealed water-cooling channel inside, which achieves forced heat dissipation through circulating cooling water.

[0004] In thermodynamic analysis of metallurgical processes, when the heat energy generated by the electrode arc heats the furnace environment to 1500-1600°C, the furnace roof cooling system begins to exhibit significant thermodynamic contradictions. According to heat transfer calculations, at a 2000°C melt pool temperature, the heat radiation intensity of the furnace roof surface can reach 120kW / m², while the heat forcibly removed by the water cooling system accounts for approximately 18-22% of the total energy input. This leads to three key problems: First, excessive heat loss reduces the thermal efficiency of the electric furnace; second, excessive cooling of the melt pool surface forms a "cold shell," prolonging the melting time; and finally, to compensate for this heat loss, the arc power is increased, resulting in increased electricity consumption per ton of steel produced.

[0005] Specifically, the defects of existing water-cooled furnace roofs are more pronounced when smelting high-melting-point alloys (such as ferromolybdenum, melting point 2623°C). Thermal imaging monitoring shows a temperature gradient of 400°C / cm in the center of the furnace roof. This rapid cooling rate causes thermal stress cracks within the refractory material (corundum castable, refractoriness 2100°C), significantly reducing its service life. Furthermore, the heat removed by the cooling water also results in electrical energy loss.

[0006] This thermodynamic imbalance stems from the structural contradiction of the existing cooling system: it is necessary to ensure the structural strength of the furnace cover while maintaining sufficient cooling efficiency. Summary of the Invention

[0007] The purpose of the present invention is to provide a prefabricated furnace cover for the production of electric arc furnaces for casting zirconium corundum refractory bricks and a preparation method thereof. By using waste refractory materials as the main raw materials, not only the heat preservation and energy saving effects are achieved, the melting quality of the slurry and the product quality are improved, but also the production costs can be reduced, while the impact of industrial waste on the environment is reduced.

[0008] In order to achieve the above object, the present invention adopts the following technical means: A prefabricated furnace cover for an electric arc furnace used for melting and casting zirconium corundum refractory bricks comprises, by weight percentage, 38-42% of waste sintered zirconium bricks, 54-58% of α-β corundum waste, 3.5-4.2% of aluminum dihydrogen phosphate, 1.2-1.8% of high-alumina cement, and 0.5-1% of nano-alumina powder.

[0009] Preferably, the zirconium oxide content of the waste sintered zirconium bricks is not less than 65%, and the content of the waste sintered zirconium bricks with a particle size of 0-1 mm is 30%, and the content of the waste sintered zirconium bricks with a particle size of 1-3 mm is 70%.

[0010] Furthermore, the alumina content of the α-β corundum waste is not less than 99%, and the particle size distribution D50 is 180 μm.

[0011] Furthermore, the alumina content of the high alumina cement is not less than 70%.

[0012] In addition, a preparation method for the aforementioned prefabricated furnace cover for the production of electric arc furnaces for casting zirconium corundum refractory bricks sequentially performs raw material pretreatment, three-stage batching, planetary mixing, hydraulic vibration forming, step-by-step drying and high-temperature sintering.

[0013] Preferably, planetary mixing is carried out in a planetary mixer, and the humidity is controlled at 3.5-4.2% during the mixing process.

[0014] Furthermore, during the hydraulic vibration forming, the frequency was set to 50 Hz and the amplitude was set to 2 mm.

[0015] Furthermore, when performing step drying, drying is performed at 60° C. for 24 h, 120° C. for 12 h, and finally at 250° C. for 6 h.

[0016] Furthermore, during high temperature sintering, the sintering temperature is 1550° C. for 8 hours.

[0017] The cover body prepared by the present invention has the following beneficial effects: The raw materials used are primarily waste sintered zirconium bricks and α-β corundum scrap. These scraps are typically scraps or discarded bricks generated during the production process. Through recycling and reuse, resources are effectively recycled. During the re-production process, aluminum dihydrogen phosphate and high-alumina cement are used to enhance the structural strength and high-temperature resistance of the furnace cover.

[0018] The thermal insulation performance of the furnace cover is significantly improved, which reduces heat loss, saves electricity, reduces production costs, helps to improve the melting quality of the liquid material, and thus improves the overall quality of the fused bricks.

[0019] After processing, the furnace cover of the present invention undergoes a phase transition from monoclinic to tetragonal zircon, forming an interlocking structure with the corundum phase. The phosphate binder forms an AlPO4 network at high temperatures, which, combined with the in-situ generated zirconium oxide toughening phase, gives the furnace cover excellent thermal insulation performance and high-temperature stability while keeping the porosity within 12-15%. This improves temperature uniformity within the furnace and reduces power consumption. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in combination with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments.

[0021] Therefore, the following detailed description of the embodiments of the present invention is not intended to limit the scope of the claimed invention, but rather merely represents selected embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort are also within the scope of protection of the present invention.

[0022] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments of the present invention can be combined with each other.

[0023] Example 1 A prefabricated furnace cover for an electric arc furnace used for melting and casting zirconium corundum refractory bricks comprises, by weight percentage, 38% of waste sintered zirconium bricks, 54% of α-β corundum waste, 3.5% of aluminum dihydrogen phosphate, 1.2% of high-alumina cement, and 0.5% of nano-alumina powder.

[0024] Preferably, the zirconium oxide content of the waste sintered zirconium bricks is not less than 65%, and the content of the waste sintered zirconium bricks with a particle size of 0-1 mm is 30%, and the content of the waste sintered zirconium bricks with a particle size of 1-3 mm is 70%.

[0025] Furthermore, the alumina content of the α-β corundum waste is not less than 99%, and the particle size distribution D50 is 180 μm.

[0026] Furthermore, the alumina content of the high alumina cement is not less than 70%.

[0027] In addition, a preparation method for the aforementioned prefabricated furnace cover for the production of electric arc furnaces for casting zirconium corundum refractory bricks sequentially performs raw material pretreatment, three-stage batching, planetary mixing, hydraulic vibration forming, step-by-step drying and high-temperature sintering.

[0028] Preferably, planetary mixing is carried out in a planetary mixer, and the humidity is controlled at 3.5-4.2% during the mixing process.

[0029] Furthermore, during the hydraulic vibration forming, the frequency was set to 50 Hz and the amplitude was set to 2 mm.

[0030] Furthermore, when performing step drying, drying is performed at 60° C. for 24 h, 120° C. for 12 h, and finally at 250° C. for 6 h.

[0031] Furthermore, during high temperature sintering, the sintering temperature is 1550° C. for 8 hours.

[0032] Example 2 A prefabricated furnace cover for an electric arc furnace used for melting and casting zirconium corundum refractory bricks comprises, by weight percentage, 42% of waste sintered zirconium bricks, 58% of α-β corundum waste, 4.2% of aluminum dihydrogen phosphate, 1.8% of high-alumina cement, and 1% of nano-alumina powder.

[0033] Preferably, the zirconium oxide content of the waste sintered zirconium bricks is not less than 65%, and the content of the waste sintered zirconium bricks with a particle size of 0-1 mm is 30%, and the content of the waste sintered zirconium bricks with a particle size of 1-3 mm is 70%.

[0034] Furthermore, the alumina content of the α-β corundum waste is not less than 99%, and the particle size distribution D50 is 180 μm.

[0035] Furthermore, the alumina content of the high alumina cement is not less than 70%.

[0036] In addition, a preparation method for the aforementioned prefabricated furnace cover for the production of electric arc furnaces for casting zirconium corundum refractory bricks sequentially performs raw material pretreatment, three-stage batching, planetary mixing, hydraulic vibration forming, step-by-step drying and high-temperature sintering.

[0037] Preferably, planetary mixing is carried out in a planetary mixer, and the humidity is controlled at 3.5-4.2% during the mixing process.

[0038] Furthermore, during the hydraulic vibration forming, the frequency was set to 50 Hz and the amplitude was set to 2 mm.

[0039] Furthermore, when performing step drying, drying is performed at 60° C. for 24 h, 120° C. for 12 h, and finally at 250° C. for 6 h.

[0040] Furthermore, during high temperature sintering, the sintering temperature is 1550° C. for 8 hours.

[0041] Example 3 A prefabricated furnace cover for an electric arc furnace used for melting and casting zirconium corundum refractory bricks comprises, by weight percentage, 40% of waste sintered zirconium bricks, 56% of α-β corundum waste, 3.8% of aluminum dihydrogen phosphate, 1.5% of high-alumina cement, and 0.8% of nano-alumina powder.

[0042] Preferably, the zirconium oxide content of the waste sintered zirconium bricks is not less than 65%, and the content of the waste sintered zirconium bricks with a particle size of 0-1 mm is 30%, and the content of the waste sintered zirconium bricks with a particle size of 1-3 mm is 70%.

[0043] Furthermore, the alumina content of the α-β corundum waste is not less than 99%, and the particle size distribution D50 is 180 μm.

[0044] Furthermore, the alumina content of the high alumina cement is not less than 70%.

[0045] In addition, a preparation method for the aforementioned prefabricated furnace cover for the production of electric arc furnaces for casting zirconium corundum refractory bricks sequentially performs raw material pretreatment, three-stage batching, planetary mixing, hydraulic vibration forming, step-by-step drying and high-temperature sintering.

[0046] Preferably, planetary mixing is carried out in a planetary mixer, and the humidity is controlled at 3.5-4.2% during the mixing process.

[0047] Furthermore, during the hydraulic vibration forming, the frequency was set to 50 Hz and the amplitude was set to 2 mm.

[0048] Furthermore, when performing step drying, drying is performed at 60° C. for 24 h, 120° C. for 12 h, and finally at 250° C. for 6 h.

[0049] Furthermore, during high temperature sintering, the sintering temperature is 1550° C. for 8 hours.

[0050] Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A prefabricated furnace cover for an electric arc furnace used for casting zirconium corundum refractory bricks, characterized in that: Calculated by weight percentage, it includes 38~42% of waste sintered zirconium bricks, 54~58% of α-β corundum waste, 3.5~4.2% of aluminum dihydrogen phosphate, 1.2~1.8% of high alumina cement, and 0.5~1% of nano alumina powder.

2. The prefabricated furnace cover for producing electric arc furnace for melting and casting zirconium corundum refractory bricks according to claim 1 is characterized in that: The zirconium oxide content of the waste sintered zirconium bricks is not less than 65%, and the content of the waste sintered zirconium bricks with a particle size of 0-1 mm is 30%, and the content of the waste sintered zirconium bricks with a particle size of 1-3 mm is 70%.

3. The prefabricated furnace cover for producing electric arc furnace for melting and casting zirconium corundum refractory bricks according to claim 1 is characterized in that: The alumina content of the α-β corundum scrap is not less than 99%, and the particle size distribution D50 is 180 μm.

4. The prefabricated furnace cover for producing electric arc furnace for melting and casting zirconium corundum refractory bricks according to claim 1 is characterized in that: The alumina content of the high alumina cement is not less than 70%.

5. A method for preparing a prefabricated furnace cover for producing electric arc furnaces for melting and casting zirconium corundum refractory bricks according to any one of claims 1 to 4, characterized in that: The materials are sequentially subjected to raw material pretreatment, three-stage batching, planetary mixing, hydraulic vibration forming, step-by-step drying and high-temperature sintering.

6. The preparation method according to claim 5, characterized in that Planetary mixing was performed in a planetary mixer, and the humidity was controlled at 3.5-4.2% during the mixing process.

7. The preparation method according to claim 5, characterized in that When performing hydraulic vibration forming, the frequency is set to 50 Hz and the amplitude is set to 2 mm.

8. The preparation method according to claim 5, characterized in that When performing step drying, the drying is carried out at 60°C for 24 hours, 120°C for 12 hours, and finally at 250°C for 6 hours.

9. The preparation method according to claim 5, characterized in that During high temperature sintering, the sintering temperature is 1550°C for 8 hours.