APPLICATION OF FRACTIONAL CRYSTLLIZATION FOR REFINING OF MOLTEN ALUMINIUM SCRAP

摘要

To promote aluminum scrap recycling, possibility of application of fractional crystallization for possibility of refining metallic impurities as silicon and iron from molten aluminum alloy and scrap such as sash, radiator and cars was investigated. Refining characteristics was evaluated both by yield rate and impurity removal efficiency. In the 8kg/charge experiment, the influence of basic experimental factors as pressure and alloy composition on the refining characteristics was investigated. Increase of pressure gives high silicon removal ratio on Al-Si binary alloy. On practical scrap, removal of silicon, copper, and iron was possible. Refining efficiency of sash and radiator scrap was better than that of car scrap. The removal efficiency is lowered by intermetallic compounds crystallizing in the solid-liquid co-existing zone.