
142 Aluminum Recycling
oxygen enrichment, the two techniques are rarely used at the same time. Regeneration
also presents the same potential disadvantages as oxygen enrichment—higher melt
loss, greater refractory wear, and high NO
x
generation (Schalles, 1998). Similar to
oxygen enrichment, recirculation of ue gases helps mitigate these concerns. An
additional problem in furnaces that use ux is the tendency of the ux to form dust
or vapor, which condenses in the regenerator. As a result, periodically the regenera-
tors must be shut down for cleaning. This involves removing the ceramic media, dis-
carding the contaminated material, and screening ...