Two studies, TRIFLE (For Analyse des gisements DEEE et optimisation des technologies de TRI des PLastiques DEEE (analysis of WEEE and optimization of sorting technologies for WEEE plastics).) and VALEEE (For VALorisation des composants, matieres et substances issus du gisement DEEE (Recovery of components, materials and substances from WEEE).), supported by the French State, the Greater Lyon area (Grand-Lyon), the Rhone-Alpes Region and the French eco-organization "Eco-systemes", and involving laboratories, recycled material users and recycler partners, were conducted concerning the characterization, sorting and recovery of French WEEE (Waste Electrical and Electronic Equipment).To determine the heterogeneity of a 10-ton batch, the WEEE was sorted into families before grinding. Specimens were dismantled and plastic particles were analyzed to estimate their composition. The batch was then crushed and the metals extracted.The residue containing plastics was sampled at the outlet of the plant and analyzed. The detailed characterization of the plastics sample was used to calculate the estimated sampling error and the overall measurement error. The sample size was determined so as to achieve satisfactory accuracy for the most represented polymers likely to be recovered after recycling.A simple characterization methodology for use by recycling plants was proposed in order to determine the plastic composition of this waste. The procedure was validated on a second 10-ton batch of sWEEE collected from another location and treated by a different recycling facility.This article presents the sampling protocol design methodology, then the characterization protocol and its usage limitations. (C) 2014 Elsevier Ltd. All rights reserved.
This study presents the approach used to develop a model for a continuous bioleaching system in stirred tank reactors. In bioleaching of metallic sulfides, precipitation concurrently occurs with dissolution of sulfides. Therefore, the model incorporates both the leaching and the precipitation kinetics. It is based on a shrinking particle model for the leaching part and a Mixed Suspension Mixed Product Removal (MSMPR) crystallizer model with germination and growing kinetics for the precipitation part.To establish the model, it was necessary to have access to the size distribution of both sulfide and precipitated particles. A procedure for the bioleached residue characterization was developed in the BRGM laboratory to be able to dissociate sulfide and precipitated particles in the solid phase.The current paper presents the analytical procedure, the mathematical model in detail and its application to a continuous pilot plant test. (c) 2012 Elsevier B.V. All rights reserved.