ã€China Aluminum Industry Network】 1. The electrolytic aluminum bath operates at high temperatures and contains a significant amount of gas. The production of electrolytic aluminum is an electrochemical process conducted under high-temperature conditions. With the advancement of technology, the capacity of electrolytic cells has increased significantly, with current intensities reaching up to 350-500 kA, and current efficiency ranging from 94% to 95%. In this process, carbon blocks are used as anodes, while semi-graphitized carbon blocks serve as cathodes. The typical operating temperature is between 950°C and 960°C. The electrolyte composition is complex, primarily consisting of cryolite, along with additions of Alâ‚‚O₃, CaFâ‚‚, and MgFâ‚‚, which are present in concentrations of 1.38–2.88%, 4.88–5.88%, and 0.47–0.87%, respectively. The moisture content includes AlF₃ (≤7.5%) and other components (≤1.0%). The moisture in these materials consists of both adsorbed water and crystalline water. Adsorbed water evaporates easily under high temperatures, while crystalline water reacts chemically within the electrolytic cell: 3Hâ‚‚O + 2Al → Alâ‚‚O₃ + 6[H]. The atomic hydrogen [H] dissolves into the molten aluminum, and the higher the temperature, the greater the saturation concentration of hydrogen. In addition to hydrogen, the electrolytic aluminum liquid also contains COâ‚‚, CO, CHâ‚„, and Nâ‚‚. The gas composition in the aluminum melt varies widely, with Hâ‚‚ making up 53–96%, COâ‚‚ 2.5–30%, CO 20%, CHâ‚„ 2.5%, and Nâ‚‚ 2.5%. For aluminum melts with high gas content, effective degassing measures must be implemented to reduce potential hazards. 2. Impurity content in electrolytic aluminum liquid. Non-metallic impurities in primary aluminum are the main concern, along with a small amount of metallic impurities. Common non-metallic impurities include aluminum oxide, followed by fluoride salts, aluminum carbide, and aluminum nitride. During the electrolysis process, sand-like alumina is added to the electrolytic cell. This type of alumina consists of α-Alâ‚‚O₃ and γ-Alâ‚‚O₃, with α-Alâ‚‚O₃ accounting for more than 25%. α-Alâ‚‚O₃ is spherical, has a high specific gravity, compact structure, and low surface area, leading to a slow dissolution rate in the electrolyte. If it dissolves too late, it may settle at the bottom of the tank and mix into the cathode aluminum liquid. On the other hand, γ-Alâ‚‚O₃ is more reactive and dissolves quickly, typically not accumulating at the bottom of the cell. Most electrolytic cells draw aluminum liquid once every 24 hours, and any α-Alâ‚‚O₃ mixed into the molten aluminum is then transferred to the smelting furnace in the casting system. Metallic impurities in the electrolyzed aluminum bath include silicon, iron, zinc, titanium, and sodium, with silicon and iron being the most significant. These impurities mainly come from two sources: first, raw materials such as alumina produced via the alkaline method contain impurities like SiOâ‚‚, Feâ‚‚O₃, TiOâ‚‚, ZnO, and Naâ‚‚O, which can lead to the formation of silicon, iron, titanium, zinc, and sodium during electrolysis. Second, they may originate from the lining of the electrolytic cell, tools, equipment, and dust. Incidentally, in high-temperature molten aluminum, carbon reacts with titanium to form TiC. TiC acts as an effective non-spontaneous nucleus during the solidification of aluminum alloys, promoting better nucleation compared to TiBâ‚‚ particles, thus favoring the crystallization of the alloy. However, the presence of TiC is limited, which hinders grain refinement. China is one of the largest producers of primary aluminum globally. It employs a short-process technique, using solar cells to directly produce slabs and round ingots needed for aluminum processing. This approach is considered a key development path for the aluminum industry and has attracted significant attention from relevant authorities. Several large electrolytic aluminum enterprises, such as Guizhou Aluminum Plant, Qinghai Aluminum Plant, Baotou Aluminum Plant, and Qingtongxia Aluminum Plant, have introduced advanced technologies and equipment from Europe and the U.S. in recent years, establishing high-tech, first-class fusion casting lines. Key equipment includes large melting furnaces, hydraulic tilting furnaces, high-power electromagnetic stirrers, on-line argon gas degassing systems, hydraulic casting machines, and ingot homogenization equipment. Through trial production, these facilities have achieved good product quality and brought about favorable economic and environmental benefits. On the other hand, some companies have invested millions of dollars to build three 15-ton melting furnaces, two wire rope casting machines, a monorail crane, and a set of outdated, low-temperature, low-efficiency equipment capable of producing 5,000 tons per year. However, the equipment is basic, the technology is outdated, and management is lacking, resulting in poor product quality and accumulated issues. For such enterprises, it is essential to carry out equipment upgrades, strengthen technical management, improve process technologies, and refine the overall process system to ensure the production of qualified products. Loader Parts,Track Loader Parts,Case Loader Parts,Skid Loader Parts JINING SHANTE SONGZHENG CONSTRUCTION MACHINERY CO.LTD , https://www.stszcmparts.com