(English translation of Japanese paper) Special feature

As the demand for high quality Aluminum has been increased, the molten metal refining processes in cast shop has been more and more regarded as important. Furthermore, nowadays both molten metal quality and environmental issues are important and the demand from environmental aspect is increasing particularly in Europe and the USA. As regards to the behavior of Hydrogen in molten Aluminum and the mechanism of degassing, many reports and presentations have been made so far 1)~7). Here this paper presents the recent foreign molten metal refining system to be applied in furnaces and in-line process. [Refining process in furnace] Even in the case where any in-line molten metal refining process (degassing and filtration) is used, the molten metal refining process in furnace is required to improve molten metal quality. Injection of gas mainly consisting Chlorine into molten metal has been common method as for molten metal refining process in furnace, which has been employed by refining and casting plants throughout the world. TAC8) system (Alcan) removes Sodium as dross (Na3AlF6-AlF3-Al2O3) by converting Sodium in molten metal to Na3AlF6 using Fluoride. On the other hand, MIXAL9) method (Pechiney) injects Ar-20%Cl ga