Modelling material separation processes in bulk recycling

Increasing environmental concerns about the disposal of mass produced products have resulted in efforts to recover value from components and materials before discarding such products. Methods include incineration, disassembly or de-manufacturing and bulk recycling. This paper investigates several cases of the problem of selecting the best sequence for recovery of materials by bulk recycling. A solution procedure for determining the optimal sequence for isolating all target materials present in a given batch based on dynamic programming is presented. A modification for targeting specific materials in a batch is discussed. Additional constraints arising from the operation of such facilities are also discussed. The general problem of target material identification is presented and a procedure for selecting a profitable target material mix, along with a numerical illustration, is documented. Finally, the integrated consideration of bulk recycling and disassembly for evaluating product disposal costs is presented. © 1999 Taylor & Francis Group, LLC