
237Dross Processing
indicate metal recovered by drainage from the processing unit; darker regions indi-
cate aluminum recovery from subsequent rotary furnace processing. As might be
expected, more expensive methods tend to produce the best results; whether the
value of the additional metal recovered justies the higher equipment cost depends
upon a variety of factors.
cOmmiNutiON
With the exception of AROS units, dross coolers generate a product with a wide size
range, from dust to chunks of several centimeters. As previously mentioned, the larg-
est chunks have high enough metal content to remelt, while smaller pieces require
upgrading to separat ...