High-speed homogenization double-channel casting method and device for casting aluminum ingot for green electrolytic aluminum production

Abstract

The invention discloses a high-speed homogenization double-channel casting method and device for aluminum ingot casting for green electrolytic aluminum production, and the method comprises the following steps: placing a preheated regenerated aluminum ingot in the middle of a mixed heat preservation furnace, and pouring electrolytic primary aluminum liquid produced on the same day into the mixed heat preservation furnace from the aluminum injection end and the middle of the mixed heat preservation furnace at the same time within 60 minutes; and a refining agent accounting for 0.03-0.06% of the total mass of the molten aluminum is added, the drossing molten aluminum is stirred and then stands for 10-20 min, then the content of all impurity elements in the mixed molten aluminum is analyzed through fixed-point sampling, the qualified molten aluminum is subjected to ingot casting and warehousing according to the detection result, and aluminum ingots are obtained. The impurity element content of each part of the obtained aluminum ingot is uniform, and the total mass fraction of the Fe element is less than 0.20%; the sum of the mass fractions of the Si element is less than 0.12%; the sum of the mass fractions of Ga elements is less than 0.03%, and the sum of the mass fractions of impurities is less than 0.30%.

Description

Technical Field

[0001] The present application relates to the technical field of electrolytic aluminum production, and in particular to a high-speed homogenized dual-channel casting method and device for casting aluminum ingots for green electrolytic aluminum production. Background Art

[0002] The electrolytic aluminum industry adopts the cryolite-alumina molten salt electrolysis method. With molten cryolite as solvent, alumina as solute, carbonite as anode, and aluminum liquid as cathode, after direct current is passed, the aluminum oxide is reduced to aluminum liquid by electrochemical reaction at 950-970℃ using an electrolytic aluminum cell. During the electrolysis process, in order to promote the forward electrolysis reaction, it is necessary to regularly pump a large amount of aluminum liquid in the electrolytic cell into the ladle. After metering, the ladle sends the aluminum liquid to the foundry for quality adjustment, refining, and adjustment of the aluminum liquid temperature, and then removes impurities in the aluminum liquid and casts it into commercial aluminum ingots.

[0003] In order to improve the production output and processing efficiency of electrolytic aluminum, 500kA series large prebaked electrolytic cells are mainly used for production. In order to further increase the output, large prebaked electrolytic cells are arranged in pairs in production. The subsequent process of prebaked electrolytic cells is casting. In the casting process, multiple mixed insulation furnaces and production lines are set up to timely process the aluminum liquid output from the prebaked electrolytic cells. When the aluminum liquid is transferred from the prebaked electrolytic cell to the casting process, it is mainly completed by lifting the ladle. After the ladle is transferred to the designated location, a ladle tilter matching the ladle is required to pour the aluminum liquid in the ladle into the mixed insulation furnace.

[0004] When aluminum manufacturers for export stop production or our company stops production in large numbers, production capacity increases significantly. The pouring speed of the existing ladle tipper cannot keep up with the aluminum output speed, making it difficult to maintain continuous production and delaying production.

[0005] Because ordinary remelting aluminum ingots do not need to add other metal elements, the quality of the liquid aluminum flowing into the mixing insulation furnace from the aluminum injection port of the mixing insulation furnace is basically uniform. After the slag is removed and stirred by the slag removal car, there will be no segregation of metal elements in the aluminum liquid. The product quality is uniform and the tilting device can also meet the production needs.

[0006] When it is necessary to add recycled aluminum ingots to liquid aluminum, since the raw materials of recycled aluminum ingots contain high impurities, especially the metal zinc content is more than 10 times the standard of ordinary aluminum ingots, such waste recycled aluminum ingots are directly placed in the insulation furnace and melted by the transfer aluminum liquid temperature. However, due to the long length of the mixed insulation furnace and the lack of an effective stirring device, the aluminum liquid added with the recycled aluminum ingots cannot be fully and evenly stirred, and can only rely on the conventional stirring and mixing operation of the slag truck. The flow rate of the aluminum liquid is slow, which affects the uniform content of the alloy elements added to each part of the liquid aluminum, and the quality is difficult to control uniformly. The aluminum ingot products made by adding recycled aluminum ingots have serious metal element segregation, which affects the product quality and the normal recycling of the recycled aluminum ingots.

[0007] How to mix the flow of molten aluminum in the insulation furnace and shorten the time of pouring aluminum into the furnace is an issue that needs to be studied urgently.

[0008] The information disclosed in the background technology section is only intended to enhance the understanding of the overall background of the invention and should not be regarded as an admission or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art. Summary of the invention

[0009] In response to the above-mentioned technical problems, the present application provides a high-speed homogenized dual-channel casting method and device for casting aluminum ingots for green electrolytic aluminum production. The method can improve the fluidity of molten aluminum in a strengthened mixed insulation furnace, thereby evenly distributing the metal elements in the molten aluminum that requires the addition of alloying elements, thereby improving product quality and avoiding the occurrence of metal element segregation.

[0010] The present application provides a high-speed homogenization dual-channel casting method for casting aluminum ingots for green electrolytic aluminum production, comprising the following steps:

[0011] Place the preheated recycled aluminum ingot in the middle of the mixed insulation furnace, and pour the electrolytic aluminum liquid produced that day into the mixed insulation furnace from the aluminum injection end and the middle of the mixed insulation furnace at the same time, and complete the pouring within 60 minutes;

[0012] Add 0.03-0.06% of the total weight of the aluminum liquid as a refining agent, stir the aluminum liquid, and then let it stand for 10-20 minutes. Then, take samples at fixed points to analyze the content of each impurity element in the mixed aluminum liquid. According to the test results, the aluminum liquid that passes the test is cast into an ingot and stored to obtain an aluminum ingot;

[0013] The length of the mixed holding furnace is 10 to 12 m;

[0014] The amount of recycled aluminum ingots added is calculated based on the impurity content in the recycled aluminum ingots used and the impurity content in the electrolytic aluminum of the day. The actual amount added is 80-90% of the calculated amount. The total mass fraction of impurities contained in the recycled aluminum ingots used is ≤4%;

[0015] The flow rate of the transported aluminum liquid at the aluminum injection end of the mixed holding furnace is 1.5 to 2 tons / min;

[0016] The flow rate of the aluminum liquid transferred in the middle of the mixed insulation furnace is 1.5 to 2.3 tons / min.

[0017] Preferably, the mass fraction range of impurities contained in the recycled aluminum ingot meets the following requirements: Si≤0.6%, Fe≤0.8%, Cu≤0.25%, Mn≤0.85%, Mg≤1.6%, Zn≤0.4%, Ti≤0.15%, V≤0.03%, Ga≤0.05%, and the content of other non-Al elements except Si, Fe, Cu, Mn, Mg, Zn, Ti, V and Ga is ≤0.09%.

[0018] Preferably, the total mass fraction of Fe element in the obtained aluminum ingot is less than 0.20%; the total mass fraction of Si element is less than 0.12%; the total mass fraction of Ga element is less than 0.03%, and the total mass fraction of impurities is less than 0.30%.

[0019] Preferably, the total mass fraction of Fe element in the obtained aluminum ingot is less than 0.15%; the total mass fraction of Si element is less than 0.10%; the total mass fraction of Ga element is less than 0.03%, and the total mass fraction of impurities is less than 0.30%.

[0020] Preferably, the preheating operation of the recycled aluminum ingot is as follows: the recycled aluminum ingot to be preheated is placed outside the aluminum injection end of the mixed insulation furnace, and preheated for 1.5 to 2.5 hours to complete the preheating by preheating the recycled aluminum ingot to 390 to 420°C.

[0021] Preferably, a chute is arranged in the middle area of ​​the mixing insulation furnace; one end of the chute is an aluminum injection port, which extends into the furnace body of the mixing insulation furnace and is connected to the inner cavity in the middle area of ​​the mixing insulation furnace, and the other end is connected to the aluminum discharge ladle.

[0022] Preferably, the refining agent is prepared by mixing 45% NaCl and 55% KCl.

[0023] Another aspect of the present application also provides a chute device for use in the above method, comprising: a chute body, a refractory brick injection layer; a refractory brick injection layer is arranged on the inner wall of the chute body; one end of the chute body is connected to the lifting bag; the other end of the chute body is connected to the mixing insulation furnace; the inner bottom surface of the chute body is an inclined surface.

[0024] Preferably, the angle between the bottom surface of the tank body and the horizontal plane is 10-15°.

[0025] Preferably, the thickness of the refractory brick injection layer is 140-160 mm.

[0026] Preferably, the trough body comprises: an end trough and a slide trough; the cross-sectional area of ​​the end trough is larger than the cross-sectional area of ​​the slide trough; one end of the slide trough is connected to the middle side wall of the end trough, and the other end extends obliquely toward the mixing insulation furnace.

[0027] The beneficial effects of this application include:

[0028] 1) The high-speed homogenized dual-channel casting method and device for casting aluminum ingots for green electrolytic aluminum production provided in this application can ensure continuous production after the liquid aluminum output is greatly increased without increasing the investment in equipment and factory buildings, effectively increase the amount of liquid aluminum dumped per unit time, reduce the input of stored products, and at the same time improve the uniformity of distribution of various metal elements in the liquid aluminum obtained by adding recycled aluminum ingots, avoid the occurrence of metal element segregation, and improve product quality.

[0029] 2) The high-speed homogenized dual-channel casting method and device for casting aluminum ingots for green electrolytic aluminum production provided in this application has uniform impurity element content in each part of the obtained aluminum ingot, which meets the national standard requirements of the total mass fraction of Fe element <0.20%; the total mass fraction of Si element <0.12%; the total mass fraction of Ga element <0.03%, and the total mass fraction of impurities <0.30%. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 A schematic front view of a chute in at least one embodiment provided in the present application;

[0031] Figure 2 A schematic top view of a chute in at least one embodiment provided in the present application;

[0032] Figure 3 A schematic side view of a chute in at least one embodiment provided in the present application;

[0033] Figure 4 A schematic flow chart of a high-speed homogenization dual-channel casting method for casting aluminum ingots for at least one green electrolytic aluminum production provided in the present application;

[0034] Legend:

[0035] The tank body 1, the bracket 2, the refractory brick injection layer 3, the end tank 11, and the slide tank 112. DETAILED DESCRIPTION

[0036] 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 conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0037] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0038] The technical means that are not described in detail in this application and are not used to solve the technical problems of this application are all set according to the common knowledge in the field, and can be implemented in a variety of common knowledge settings.

[0039] See also Figure 4The high-speed homogenization dual-channel casting method for casting aluminum ingots for green electrolytic aluminum production provided in the present application comprises the following steps:

[0040] Place the preheated recycled aluminum ingot in the middle of the mixed insulation furnace, and pour the electrolytic aluminum liquid produced that day into the mixed insulation furnace from the aluminum injection end and the middle of the mixed insulation furnace at the same time, and complete the pouring within 60 minutes;

[0041] Add 0.03-0.06% of the total weight of the aluminum liquid as a refining agent, stir the aluminum liquid, and then let it stand for 10-20 minutes. Then, take samples at fixed points to analyze the content of each impurity element in the mixed aluminum liquid. According to the test results, the aluminum liquid that passes the test is cast into an ingot and stored to obtain an aluminum ingot;

[0042] The length of the mixed holding furnace is 10 to 12 m;

[0043] The amount of recycled aluminum ingots added is determined based on the impurity content in the recycled aluminum ingots used and the impurity content in the electrolytic aluminum of the day, and the weight ratio of each impurity is determined;

[0044] The total mass fraction of impurities contained in the recycled aluminum ingots used is ≤4%;

[0045] The flow rate of the aluminum liquid transported at the aluminum injection end of the mixed holding furnace is 2.5 to 3.6 tons / min;

[0046] The flow rate of the transported aluminum liquid in the middle of the mixing and holding furnace is 1.6 to 2.3 tons / min.

[0047] By using the recycled aluminum ingot to carry out the above production process, an aluminum ingot that meets the quality requirements can be obtained. The content of each impurity element in the obtained aluminum ingot is uniformly distributed through fixed-point sampling and detection. The test results show that the content of metal elements at each detection point in the aluminum liquid meets the requirements, and no segregation occurs in the obtained aluminum ingot. The above method is used to dump and transfer aluminum liquid in the mixed insulation furnace to ensure that the recycled aluminum ingots cast by mixing waste are effectively melted, improve the quality of the products obtained after the recycled aluminum ingots are reused, and avoid the occurrence of metal element segregation.

[0048] By preheating the recycled aluminum ingots to remove the moisture contained in the recycled aluminum, explosion accidents can be prevented during the addition process. On the one hand, the recycled aluminum can be melted better. At the same time, the melted recycled aluminum liquid moves to both ends of the mixed insulation furnace with the transported liquid aluminum, and the liquid aluminum injected into the mixed insulation furnace will contact the recycled aluminum ingots, so as to improve the uniformity of the distribution of the aluminum liquid of the recycled aluminum ingots in the transported aluminum liquid by using the pouring liquid flow, and achieve uniform distribution in the mixed insulation furnace with a length of 10 to 12 meters. Without the help of other equipment for stirring, the metal element segregation phenomenon in the aluminum liquid obtained by adding the recycled aluminum liquid can be avoided, and the product quality can be improved. After adding the refining agent according to this ratio, impurities and bubbles can be removed, the fluidity of the aluminum liquid can be enhanced, the mixing of materials can be promoted, and the quality of the aluminum liquid obtained by adding the recycled aluminum ingot can be improved. The preheated recycled aluminum is added to the middle area of ​​the mixed insulation furnace so that the transported aluminum liquid can fully flush the melted recycled aluminum ingots to ensure that the aluminum liquid is evenly distributed in the furnace after the recycled aluminum ingots are melted.

[0049] In a specific embodiment, the mass fraction range of impurities contained in the recycled aluminum ingots meets the following requirements: Si≤0.6%, Fe≤0.8%, Cu≤0.25%, Mn≤0.85%, Mg≤1.6%, Zn≤0.4%, Ti≤0.15%, V≤0.03%, Ga≤0.05%, and other single ≤0.09%. The use of recycled aluminum ingots that meet this requirement for production can ensure that the quality of aluminum materials obtained in subsequent production is good and can meet quality requirements. Other single refers to the content of each non-Al element except Si, Fe, Cu, Mn, Mg, Zn, Ti, V, and Ga is ≤0.09%.

[0050] In a specific embodiment, after the recycled aluminum ingot is used by the method, the obtained aluminum ingot meets the national standard GB / T1196-2002 "Quality Standard of Aluminum Ingot for Remelting": AL99.70, Fe is not more than (0.20%), Si is not more than (0.12%), Ga is not more than (0.03%), and the total impurities are not more than (0.30%);

[0051] In a specific embodiment, the impurity contents in the aluminum ingots produced by this method meet the requirements that Fe is not greater than (0.15%), Si is not greater than (0.10%), Ga is not greater than (0.03%), and the total of all impurities is not greater than (0.30%).

[0052] In a specific embodiment, the allowable range of the impurity element content in the recycled aluminum ingot is shown in the following table: (mass fraction / %, ≤)

[0053] Si Fe Cu Mn Mg Zn Ti V Ga Other single sum 0.6 0.8 0.25 0.85 1.6 0.4 0.15 0.03 0.05 0.09 4

[0054] In a specific embodiment, the surface of the recycled aluminum ingot should be clean, free of oil stains, and free of serious slag inclusions, flash or pores.

[0055] In a specific embodiment, the fracture structure of the recycled aluminum ingot should be dense and should not contain slag or slag inclusions.

[0056] In a specific embodiment, a single batch of recycled aluminum ingots has a stable metal content, uniform composition, and no segregation.

[0057] In a specific embodiment, the size of the strip aluminum ingot is about 650×105×70 mm, and the weight of a single ingot is about 10.5 kg.

[0058] In order to improve the transfer efficiency of the transferred filtrate, a platform can be set up on the feed end of the chute, and the lifting bag can be placed on the platform to increase the transfer volume according to the previous production needs. The platform includes: a frame, and the overall structure is light and easy to transfer and use according to production needs.

[0059] In a specific embodiment, the height of the platform is 1000 mm, and the width and length are both 2200 mm. The platform is used to facilitate the operator to rotate the lifting bag when pouring and transferring aluminum liquid in the middle of the mixing and holding furnace.

[0060] See also Figures 1 to 3 The present application also provides a chute device as used in the above method, the chute comprising: a chute body 1, a bracket 2, and a refractory brick injection layer 3; the chute body 1 is installed on the bracket 2; the injection end height of the bottom surface of the chute body 1 is lower than the feed end height; the refractory brick injection layer 3 is laid on the inner wall of the chute body 1.

[0061] The chute with this structure can increase the flow rate of the aluminum liquid in transfer, improve the transfer efficiency, and complete the transfer in time after the output of the previous process section increases, ensuring the normal continuous production. It can also increase the amount of aluminum liquid transferred into the mixed insulation furnace according to changes in production conditions.

[0062] In a specific embodiment, the angle between the bottom surface of the tank body 1 and the horizontal plane is 10-15°. This setting can increase the feeding speed while allowing the transported aluminum liquid to generate an impact force to melt the regenerated aluminum ingots, and evenly push the melted regenerated aluminum liquid to both ends of the mixed insulation furnace, thereby avoiding the segregation of metal elements. The selection of this angle can also prevent the transported aluminum liquid from flowing too fast and causing splashing.

[0063] In a specific embodiment, a hanger is provided on the top feed end of the tank body 1 to facilitate transportation by a gantry crane.

[0064] In a specific embodiment, the inner bottom surface of the tank body 1 is an inclined surface, so as to accelerate the flow speed of the transported aluminum liquid.

[0065] In a specific embodiment, the tank body 1 includes: an end tank 11 and a chute 112; the end tank 11 is arranged on the feeding end of the tank body 1; one end of the chute 112 is connected to the end tank 11, and the other end is connected to the mixing and holding furnace. This arrangement can increase the feeding amount of aluminum liquid during feeding, and enter the mixing and holding furnace through the chute 112.

[0066] In a specific embodiment, the height of the support 2 below the injection end of the tank body 1 is 1000-1200 mm.

[0067] In a specific embodiment, the thickness of the refractory brick injection layer 3 is 140-160 mm.

[0068] The ladle tilter used in this application is a commercially available product. The ladle tilter consists of a chassis, a ladle stopper, a side clamp, a hydraulic system, a furnace door oil pump, a tilter oil pump, a control system, a hydraulic cooling system, and a remote control device. The hydraulic system provides kinetic energy. The power of the furnace door cylinder motor and the tilting cylinder motor are both 11KW. The furnace door cylinder system pressure is 12mPa, and the tilting cylinder system pressure is 16mPa. The hydraulic cooling uses air cooling. The thermostat automatically controls the oil temperature. The tilter oil pump model is P22-A3-FP-01. During work, the ladle is raised and lowered using a remote control, and the pouring time for each bag of aluminum liquid is 10-12 minutes.

[0069] In a specific embodiment, the hybrid insulation furnace used includes: a furnace body, a hydraulic furnace door device, a hydraulic ladle lifting device, a furnace door hood, a smoke exhaust duct, a silicon carbon rod, an electrical control system, etc.

[0070] Rated voltage of the furnace body: three-phase 380V; frequency: 50HZ; rated temperature: 1050℃;

[0071] Rated power: 1200KW; Heating element: Silicon carbon rods produced in Shenyang are used for heating; Furnace temperature uniformity: ±8℃; Temperature control accuracy: ±5℃. (High-precision thyristor controlled heating); Feeding method: Remote control handle controls the lifting and filling of the bag and manual feeding; Furnace door lifting: Remote control handle controls the lifting and lifting; Furnace body capacity: 60 tons; Control PLC: SIMATIC S7-1500; Temperature controller: NHR-8612; Amperemeter: NHR-3300C

[0072] Working principle and features: The heating temperature is monitored by a microcomputer intelligent instrument. The PLC collects temperature meter data through the RS485 communication port to perform PID closed-loop self-tuning to control heating. Electric heating multi-zone synchronous control technology, the furnace temperature can be recorded throughout the process. The heating current value is visible in real time. Load constant current, constant voltage, constant power control technology, with "manual" and "automatic constant temperature" setting modes optional; all set parameter data are automatically saved and not lost; the temperature uniformity in the furnace can reach within ±8℃.

[0073] Example

[0074] Unless otherwise specified, the materials and instruments used in the following examples were obtained from commercial channels; the detection methods used were all existing methods unless otherwise specified.

[0075] Example 1

[0076] 1) Open the hood door of the mixed protection furnace, place a dumper on the outside of the furnace wall 5 meters away from the aluminum injection end of the mixed protection furnace, and determine the amount of recycled aluminum added according to the impurity content of the recycled aluminum used and the content of various impurities in the electrolytic aluminum of the day, and the mass proportion of each impurity:

[0077] The recycled aluminum ingots used include: impurity elements with a total mass fraction of ≤4%, and the balance being aluminum.

[0078] The impurities contained in the recycled aluminum ingots (mass fraction / %, ≤) are shown in the following table:

[0079] Si Fe Cu Mn Mg Zn Ti V Ga Other single sum 0.6 0.8 0.25 0.85 1.6 0.4 0.15 0.03 0.05 0.09 4

[0080] The results of random inspection of electrolytic aluminum liquid produced on that day are shown in the following table:

[0081] Si Fe Cu Mn Mg Zn Ti V Ga Other single sum 0.046 0.10 0.00058 0.001 0.0034 0.018 0.002 0.025 0.018 0.007 0.22

[0082] Based on the element ratio requirements for the production of aluminum ingots, it was determined through calculation that 1.2 tons of recycled aluminum ingots should be added to each furnace of molten aluminum. In order to ensure product quality, 1 ton of recycled aluminum was actually added to each furnace of molten aluminum.

[0083] The calculation process is as follows: Under the premise of ensuring that the single impurity content of liquid aluminum does not exceed the standard (the impurity content of each electrolytic cell has been adjusted before the furnace is equipped), prepare aluminum liquid with an AL content of 99.70%, assuming that the total amount of impurities does not exceed 0.3%, each furnace of aluminum liquid is 60 tons, and the impurity content is 0.22%. According to the sampling results of the electrolytic aluminum liquid produced on the day, the total amount of impurities in the electrolytic aluminum liquid produced on the day is calculated to be 60*0.22%=0.132 tons, the maximum impurity content of each furnace of aluminum liquid is 60*0.3%=0.18 tons, and the maximum weight of recycled aluminum added to each furnace is (0.18-0.132) / 0.04=1.2 (tons).

[0084] According to the amount of recycled aluminum added, after weighing the mass of recycled aluminum, first put the recycled aluminum in the dumper position at the feed inlet of the mixed insulation furnace, and use the high temperature in the mixed protection furnace to preheat the recycled aluminum ingots. Each furnace of recycled aluminum is preheated for 2 hours, and the recycled aluminum is preheated to 400°C;

[0085] 2) A chute is arranged in the middle area of ​​the mixing insulation furnace, one end of the chute is an aluminum injection port, the aluminum injection port extends into the furnace body of the mixing insulation furnace and is connected with the inner cavity in the middle area of ​​the mixing insulation furnace, and the other end is connected with the aluminum discharge ladle; the discharge port of the dumper is arranged at one end of the mixing insulation furnace; all parts of the mixing insulation furnace can be opened and locked as needed.

[0086] 3) The aluminum liquid is transferred to the mixed insulation furnace through the chute and the dumper at the same time. The aluminum liquid flowing out of the chute directly dissolves the regenerated aluminum ingots. The capacity of the mixed protection furnace is 60 tons, and the aluminum liquid capacity of each aluminum ladle is 10-12 tons. Each furnace requires 5 bags of liquid aluminum, of which 3 bags are injected into the mixed protection furnace through the dumper, and the other 2 bags are injected into the mixed protection furnace through the aluminum injection chute; the flow rate of the aluminum liquid in the ladle on the dumper is 1 ton / min; the flow rate of the aluminum liquid in the ladle in the chute is 1.5 tons / min. The time for dumping is about 52 minutes. Each ladle is transferred by an overhead crane. A total of 50-60 tons of aluminum liquid are poured in. Since the material deposition on the inner wall of the ladle will cause the volume of the ladle to change when the aluminum liquid is transferred, the specific aluminum liquid cannot be accurately measured.

[0087] 4) After the melting of the recycled aluminum ingot is completed, the refining agent is evenly sprinkled into the mixed protection furnace. The forklift operator stirs and removes the slag from the liquid aluminum in the furnace. After the aluminum liquid is left to stand for 15 minutes, the mixed aluminum liquid is sampled and analyzed at a fixed point. According to the test results, the qualified aluminum liquid is cast into the warehouse;

[0088] The refining agent used is a mixture of 45% NaCl and 55% KCl, and the amount of the refining agent added is 0.05% of the total mass of the aluminum liquid.

[0089] After using the recycled aluminum ingots by this method, the obtained aluminum ingots meet the national standard GB / T1196-2002 "Quality Standard for Aluminum Ingots for Remelting", specifically: Fe is 0.10%, Si is 0.10%, Ga is 0.02%, the total impurities are 0.20%, and the balance is aluminum.

[0090] Example 2

[0091] The difference from Example 1 is that: each furnace of recycled aluminum is preheated for 1.5 hours, and the recycled aluminum is preheated to 390°C; the flow rate of the aluminum liquid in the ladle on the pourer is 1.5 tons / min; the flow rate of the aluminum liquid in the ladle in the chute is 2 tons / min. The time for dumping is about 36 minutes. The aluminum liquid is stirred and then left to stand for 10 minutes; the amount of refining agent added is 0.06% of the total mass of the aluminum liquid.

[0092] The impurities in the aluminum ingot produced by the method are: Fe is 0.14%, Si is 0.09%, Ga is 0.02%, the total of all impurities is 0.20%, and the balance is aluminum.

[0093] Example 3

[0094] The difference from Example 1 is that: each furnace of recycled aluminum is preheated for 2.5 hours, and the recycled aluminum is preheated to 420°C; the flow rate of the aluminum liquid in the ladle on the pourer is 2 tons / min; the flow rate of the aluminum liquid in the ladle in the chute is 2.3 tons / min. The time for pouring is 30 minutes. The aluminum liquid is stirred and then left to stand for 20 minutes; the amount of refining agent added is 0.03% of the total mass of the aluminum liquid.

[0095] 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 protection scope of the present invention.

Claims

1. A high-speed homogenization dual-channel casting method for casting aluminum ingots for green electrolytic aluminum production, characterized in that: The following steps are involved: Place the preheated recycled aluminum ingot in the middle of the mixed insulation furnace, and pour the electrolytic aluminum liquid produced that day into the mixed insulation furnace from the aluminum injection end and the middle of the mixed insulation furnace at the same time, and complete the pouring within 60 minutes; Add 0.03-0.06% of the total weight of the aluminum liquid as a refining agent, stir the aluminum liquid, and then let it stand for 10-20 minutes. Then, take samples at fixed points to analyze the content of each impurity element in the mixed aluminum liquid. According to the test results, the aluminum liquid that passes the test is cast into an ingot and stored to obtain an aluminum ingot; The length of the mixed holding furnace is 10 to 12 m; The amount of recycled aluminum ingots added is calculated based on the impurity content in the recycled aluminum ingots used and the impurity content in the original aluminum electrolyzed on the day, and the actual amount added is 80-90% of the calculated amount; The total mass fraction of impurities contained in the recycled aluminum ingots used is ≤4%; The flow rate of the transported aluminum liquid at the aluminum injection end of the mixed holding furnace is 1.5 to 2 tons / min; The flow rate of the aluminum liquid transferred in the middle of the mixed insulation furnace is 1.5 to 2.3 tons / min.

2. The high-speed homogenization dual-channel casting of aluminum ingots for green electrolytic aluminum production according to claim 1 is characterized in that: The mass fraction range of impurities contained in the recycled aluminum ingots meets the requirements of Si≤0.6%, Fe≤0.8%, Cu≤0.25%, Mn≤0.85%, Mg≤1.6%, Zn≤0.4%, Ti≤0.15%, V≤0.03%, Ga≤0.05%, and the content of other non-Al elements except Si, Fe, Cu, Mn, Mg, Zn, Ti, V and Ga is ≤0.09%.

3. The high-speed homogenization dual-channel casting of aluminum ingots for green electrolytic aluminum production according to claim 1 is characterized in that: The total mass fraction of Fe element in the obtained aluminum ingot is < 0.20%; the total mass fraction of Si elements <0.12%; the total mass fraction of Ga elements < 0.03%, the total mass fraction of impurities is less than 0.30%.

4. The high-speed homogenization dual-channel casting method for casting aluminum ingots for green electrolytic aluminum production according to claim 1 is characterized in that: The total mass fraction of Fe element in the obtained aluminum ingot is less than 0.15%; the total mass fraction of Si element is less than 0.10%; the total mass fraction of Ga element is less than 0.03%, and the total mass fraction of impurities is less than 0.30%.

5. The high-speed homogenization dual-channel casting method for casting aluminum ingots for green electrolytic aluminum production according to claim 1 is characterized in that: Preheating operation of recycled aluminum ingots: Place the recycled aluminum ingots to be preheated on the outside of the aluminum injection end of the mixed insulation furnace, preheat for 1.5 to 2.5 hours, and preheat the recycled aluminum ingots to 390 to 420°C to complete the preheating.

6. The high-speed homogenization dual-channel casting method for casting aluminum ingots for green electrolytic aluminum production according to claim 1 is characterized in that: A chute is arranged in the middle area of ​​the mixed insulation furnace; one end of the chute is an aluminum injection port, which extends into the furnace body of the mixed insulation furnace and is connected with the inner cavity in the middle area of ​​the mixed insulation furnace, and the other end is connected with the aluminum discharge ladle.

7. The high-speed homogenization dual-channel casting method for casting aluminum ingots for green electrolytic aluminum production according to claim 1 is characterized in that: The refining agent is prepared by mixing 45% NaCl and 55% KCl.

8. A chute device for use in the method according to any one of claims 1 to 7, characterized in that: include: A trough body (1) and a refractory brick injection layer (3); the refractory brick injection layer (3) is arranged on the inner wall of the trough body (1); one end of the trough body (1) is connected to a lifting bag; the other end of the trough body (1) is connected to a mixing insulation furnace; and the inner bottom surface of the trough body (1) is an inclined surface.

9. The chute device according to claim 8, characterized in that: The angle between the inner bottom surface of the tank body (1) and the horizontal plane is 10 to 15°; The thickness of the refractory brick injection layer (3) is 140-160 mm.

10. The chute device according to claim 8, characterized in that: The trough body (1) comprises: an end trough (11) and a slide trough (112); the cross-sectional area of ​​the end trough (11) is larger than the cross-sectional area of ​​the slide trough (112); one end of the slide trough (112) is connected to the middle side wall of the end trough (11), and the other end is extended obliquely toward the mixing and heat preservation furnace.

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