The molten aluminum has enough time in the aluminum online degassing process, as long as the gas content of the molten aluminum entering the refiner is less than 0.18ml/(100g Al), the refining agent used is pure and effective, and the gas content of the aluminum melt after online refining It can reach below 0.10~0.12ml/ (100g Al), which can fully meet the requirements of producing high-quality double zero aluminum foil.
However, in casting, the situation is different from casting and rolling. One is that the flow rate is large. The soft alloy is more than 3.8 times that of casting and rolling, and the hard alloy is also more than 2.5 times that of casting and rolling. The action time of the soft alloy is only 4.7min, and the hard alloy is only 7.2min. The refining effect is far less than that of casting and rolling. The second is that the alloy composition is complex and the content is high. The content of the alloy melt is much higher than the pure casting. The gas content of aluminum, under normal circumstances, after the aluminum melt in the standing furnace is refined, the gas content of pure aluminum is 0.14 0.16 mL/ (100g Al), while 7075 alloy has 0.28 mL/ (100g Al) ) Above, this shows from another aspect that it is more difficult to reduce the gas content in 7075 alloys.
Now some aerospace materials require the gas content of 7075 alloy melt to be controlled at 0.08mlL/(100g Al), which is difficult to achieve. It requires a reasonable design of the structure, capacity, rotor speed of the aluminum online degassing device, the purity and activity of the refined gas, and the need to adopt a dual-rotor structure, use high-purity and active refining gas, appropriately expand the capacity, and extend the aluminum liquid in the refiner. The effective time in the middle can guarantee the effect of online refining.