On the one hand, at some stage in the melting system, aluminum is uncovered to the atmosphere inside the furnace in a molten or semi-melted country, which is straightforward to oxidize, without difficulty reacts with water vapor to soak up hydrogen, and is easy to shape numerous styles of non-metal slag (which includes lining fragments, chlorides, etc.) The flux of carbides, and so on.) and coarse intermetallic particles.