New characterisation method of electrical and electronic equipment wastes (WEEE).
Innovative separation and beneficiation techniques of various materials encountered in electrical and electronic equipment wastes (WEEE) is a major improvement for its recycling. Mechanical separation-oriented characterisation of WEEE was conducted in an attempt to evaluate the amenability of mechanical separation processes. Properties such as liberation degree of fractions (plastics, metals ferrous and non-ferrous), which are essential for mechanical separation, are analysed by means of a grain counting approach. Two different samples from different recycling industries were characterised in this work. The first sample is a heterogeneous material containing different types of plastics, metals (ferrous and non-ferrous), printed circuit board (PCB), rubber and wood. The second sample contains a mixture of mainly plastics. It is found for the first sample that all aluminium particles are free (100%) in all investigated size fractions. Between 92% and 95% of plastics are present as free particles; however, 67% in average of ferromagnetic particles are liberated. It can be observed that only 42% of ferromagnetic particles are free in the size fraction larger than 20mm. Particle shapes were also quantified manually particle by particle. The results show that the particle shapes as a result of shredding, turn out to be heterogeneous, thereby complicating mechanical separation processes. In addition, the separability of various materials was ascertained by a sink-float analysis and eddy current separation. The second sample was separated by automatic sensor sorting in four different products: ABS, PC-ABS, PS and rest product. The fractions were characterised by using the methodology described in this paper. The results show that the grade and liberation degree of the plastic products ABS, PC-ABS and PS are close to 100%. Sink-float separation and infrared plastic identification equipment confirms the high plastic quality. On the basis of these findings, a global separation flow sheet is proposed to improve the plastic separation of WEEE.
BRGM, 3 av. C. Guillemin, 45060 Orléans, France. n.menad@brgm.fr
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N
Menad
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Guignot
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JA
van Houwelingen
D059029:Electronic Waste / Q000032:analysis*; D004867:Equipment Design; D005411:Flame Retardants / Q000032:analysis; D010316:Particle Size; D010969:Plastics / Q000032:analysis*; D059027:Recycling; D012037:Refuse Disposal / Q000379:methods*; D013052:Spectrometry, X-Ray Emission / Q000295:instrumentation*; D013055:Spectrophotometry, Infrared / Q000295:instrumentation*
D005411:Flame Retardants; D010969:Plastics