The flux refining method has a good effect on the removal of non-metallic inclusions, but the degree of purification of the removal of non-metallic inclusions in the melt is not only related to the physical and chemical properties of the flux, but also depends to a large extent on the refining process conditions, such as the amount of flux, the contact time between the flux and the melt, the contact area, the stirring condition, and the temperature.
In order to refine aluminum alloy melts, people have developed hundreds of fluxes. Sodium and potassium-based chloride fluxes are the most widely used. For aluminum alloys with low magnesium content, sodium-potassium-based chloride refining agents have been widely used. For aluminum alloys with high magnesium content, sodium-free carnallite-based refining fluxes are used to avoid sodium brittleness.