Waste characterization and recycle in a aluminum foundry

The wastes coming out from a foundry located at Carmagnola, near Turin (West Northern Italy), producing about 30000 t/year of aluminium castings for automotive industry, are considered in this work. The moulding operation is performed by means of semi-permanent mould casting and also by means of lost foam casting. The foundry produced 12400 t of wastes in year 2002, made of the following materials: several types of muds and dusts coming from dust abatement plants (28.7%), furnace and ladle slags (21%), aluminium shavings (21%), machinery emulsions (9.8%), exhaust moulds and cores (4.7%), various materials packing (4%), refractory material from furnaces (3.5%), saline solutions containing phosphates (3.5%), wastewater treatment mud (1.6%) and other materials (1.7%). Among these wastes only slags and aluminium shavings are sold for a recycle outside the foundry; the other materials, making about 8200 t/year, are landfilled. After a careful study of the foundry production cycle, several waste materials have been studied to evaluate their reuse/recycle possibilities. Considering the obtained results the authors are able to hypothesize a reuse inside the foundry of the dusts and a kind of mud (about 1900 t/year of wastes) and a recycle outside the foundry, as inert material, of the exhaust moulds and cores and another kind of mud.