Recovery of bromine and antimony from WEEE plastics

Abstract

Current technologies for recycling plastics from WEEE separate non-flame retarded types of ABS, PS and PP from a mixed plastic stream, which contains halogens and legacy additives like PBDE and is intended to be incinerated. As an innovative alternative treatment route, we investigated whether this by-product may be used as a source of plastics, bromine and the synergist antimony trioxide (Sb2O3). The technological approach based on the CreaSolv® Process (CreaSolv® is a registered trademark of CreaCycle, GmbH, Grevenbroich) that allows a selective dissolution of flame retarded ABS and PS, respectively. These solutions are cleaned from undissolved particles by filters, and Sb2O3 is separated by a centrifuge. After removal of Sb2O3, ABS und PS solutions are separated from brominated flame retardants (BFR) and finally produced to granules of recycled ABS and PS. In this study, the technical feasibility of this approach is demonstrated in laboratory and small technical scale. Results show, that application of centrifugal forces separates Sb2O3 to more than 90 % from the dissolved polymers whereas BFR stay in solution. As known from earlier trials and as demonstrated here, subsequent cleaning separates BFR from PS and ABS by more than 98%.