ABSTRACT
As Chapter 4 pointed out, aluminum alloys produced by remelting scrap are less valuable than alloys with the same composition produced from primary metal. The reason for this is concern over the purity of the recycled metal alloy, which is often inferior to that of primary. The development of rening technology for molten aluminum is designed to eliminate this deciency, which will allow recycled metal to compete with the primary in more applications. Much of the technology used for rening molten aluminum has been introduced only in the last 30 years, and what was once a minor footnote in an aluminum production owsheet is now a major consideration.
