four à exudation

CONT: The sweat furnace is ubiquitous and useful in aluminum recycling because it provides a cheap means to separate aluminum from waste and other metals (mainly ferrous). But the sweat furnace represents outdated technology and is difficult to control as to the quality of sweated alloy it produces, the energy it wastes and the emissions it releases into the environment.
CONT: Originally conceived for the purpose of separating aluminum from iron, particularly in composite parts and assemblies (eg. an automotive piston), the sweat furnace also separates aluminum from mixed waste, including, dirt, rock, glass, rubber, plastics and other organics. First cost of the furnace is low, it can be operated by unskilled labour and it compacts loose and bulky scrap into a solid ""pig"" or ""sow"" for transportation to the secondary smelter.