The aluminum melt coming out of the furnace contains certain amounts of impurities (hydrogen, alkaline metals, slag inclusions), and these impurities will be removed in the degassing purification equipment. AdTech dual-rotor degassing unit blows out inert gas through the rotor, and generates fine bubbles by means of a rotating nozzle. The rotating nozzle is made of graphite. The nozzle structure design takes into account the uniform ejection of bubbles. The rotating impeller is used to break the bubbles, and the touch area and touch time of the bubbles and the aluminum melt further purify the role of the aluminum melt.
The degassing purification equipment treatment process is based on the principle of gas floating. The rolling element erupts and scatters the inert gas as fine bubbles into the melt. These bubbles tend to float up. The aluminum melt is purified by the following methods:
- The method of dissolving and adsorbing hydrogen into the air bubbles to remove hydrogen.
- The chemical reaction between alkaline metal and chlorine generates chlorine salt to remove alkaline metal.
- The slag inclusions are captured by bubbles, the larger slag inclusions are caught by collision with the bubbles, and the smaller slag inclusions are captured by the radial cross section of the bubble.
The main function of online ceramic foam filter is to filter the melt to remove inclusions. The simplest and most effective filtration method is still to use ceramic foam filter plates to filter on-line. According to experience: 30ppi ceramic foam filter plates can remove about 65% of the inclusions larger than 20μm in diameter, and about 40μm in diameter. 94% or more. The 40ppi ceramic foam filter plate can remove more than 88% of the inclusions larger than 20μm in diameter, and basically eliminate the inclusions larger than 40μm in diameter. Almost 40ppi foam ceramic plates are used to filter the aluminum liquid and effectively remove the melt. For the purpose of inclusions, the ceramic filter plate should be heated to above 600°C before use. According to the principle of associated slag gas, while removing impurities, the hydrogen in the melt will also decrease.