The current general molten aluminum purification method is: after the smelting furnace, connect the degassing box and the filter box through the launder, and then transfer to the mold plate for casting. In this process, the launder is long, and the molten aluminum will cause slag and gas when passing through the launder and die plate, which will affect the quality of the molten aluminum.
The molten aluminum purification method integrates degassing and filtering device to shorten the length of the flow trough as much as possible, thereby achieving the purpose of reducing the contamination of molten aluminum. The molten aluminum enters the degassing unit through the flow trough. When the molten aluminum fills the degassing box to a certain height, the nitrogen enters the aluminum melt through the ventilating bricks, and the degassing and refining operation starts.
After degassing, the hydrogen content of the melt can be greatly reduced. After degassing, the molten aluminum flows to the filter chamber next to the degassing chamber. Put the foam ceramic filter plate in the filter box. Under the action of hydrostatic pressure, it passes through the filter plate, and after the first filtration is completed, it enters the flow tank through the water outlet. In order to avoid the tumbling and slagging of the molten aluminum in the case of a large drop, the method of excessive inclination and corner angle is not used from the launder to the mold, but the launder method is used, and the guide tube is punched at the end of the launder. The aluminum liquid flows into the launder from the leaky pipe, and the pipe outlet is buried under the liquid surface of the launder to avoid oxidation and slagging. The molten aluminum is filtered through the filter plate under gravity. Two-stage CFF filtration can remove impurities larger than 10μm and purify molten aluminum. So far, the degassing and filtering operation is completed. After the above-mentioned steps are processed, a cast rod with a high degree of purification can be obtained.