Abstract
In order to recover metal elements from municipal waste incineration bottom ash, various analyses were carried out on products obtained from a typical physical sorting flow using an incineration bottom ash generated from the pretreatment kiln of a gasification and melting furnace. We investigated the correlation between concentration behaviors for various elements and made clear the existent state of elements in the feed, characteristics of the products, and the significance of each unit operation in the physical sorting flow involving comminution and separation stages.
We point out that : (1) since the oxidation of metal (especially iron) phases occurred in the kiln, peeling and/or liberation should be achieved by using a specific comminution technique, (2) air tabling was found to be an effective method for concentrating heavy metals, (3) gold followed a similar behavior to copper in the concentration flow, and (4) finer size fractions where oxidized metal phases are concentrated need to be removed in early stages of the flow but precious metals have to be recovered from the size fractions.
