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Recovery of rare earth elements - optimized elemental analysis of fluorescent lamp shredder waste
(2016)
Rare earth elements (REE) are a crucial component of fluorescence lamps. Several procedures have been developed to recovery these technological important elements. Nevertheless, actual REE recycling from fluorescence lamps is scarce so far (recovery rate of less than 1 %), with current recycling approaches concentrating on glass recovery. Since most recycling processes include several, also wet-chemical steps, a complete knowledge of the actual elemental composition of the respective mass flows is necessary for an efficient REE recovery. We tested seven different reagent mixtures for microwave-assisted digestion of fluorescent lamp shredder, including HF, HClO4, and H2O2. We determined the concentrations of 25 of the most relevant rare earth and other trace elements in the respective dilutions. Two independent digestions, one a mixture of perchlorid/nitric/hydrofluoric acid and the other aqua regia, showed the highest concentrations of 23 of these elements, excluding only Sn and Tb. The REE concentrations in the tested lamp shredder sample (stated in g/kg) were 10.2 (Y), 12.1 (La), 7.77 (Ce), 6.91 (Eu), 1.90 (Gd), and 4.11 (Tb).
Recovery of rare earth elements - optimized elemental analysis of fluorescent lamp shredder waste
(2016)
Rare earth elements (REE) are a crucial component of fluorescence lamps. Several procedures have been developed to recovery these technological important elements. Nevertheless, actual REE recycling from fluorescence lamps is scarce so far (recovery rate of less than 1 %), with current recycling approaches concentrating on glass recovery. Since most recycling processes include several, also wet-chemical steps, a complete knowledge of the actual elemental composition of the respective mass flows is necessary for an efficient REE recovery. We tested seven different reagent mixtures for microwave-assisted digestion of fluorescent lamp shredder, including HF, HClO4, and H2O2. We determined the concentrations of 25 of the most relevant rare earth and other trace elements in the respective dilutions. Two independent digestions, one a mixture of perchlorid/nitric/hydrofluoric acid and the other aqua regia, showed the highest concentrations of 23 of these elements, excluding only Sn and Tb. The REE concentrations in the tested lamp shredder sample (stated in g/kg) were 10.2 (Y), 12.1 (La), 7.77 (Ce), 6.91 (Eu), 1.90 (Gd), and 4.11 (Tb).
It is hypothesised that as a result of used electronic goods exports to developing economies, the projected energy savings made by the Ecodesign Directive at the EU level do not immediately equate to the same savings at the global level. A significant volume of the EUs inefficient used/obsolete products are exported after reaching the end of their useful life in the EU and after a relatively short second usage phase, these products become electronic waste and undergo particularly poor end of life treatment in developing countries. To determine whether the energy use of used exports could be significant, the annual energy use of EU stock and exported used products is simulated in the case of televisions, using a simplified stock model over the time period 2006 to 2025. This simulation is based on available data, estimates and simple projections for the annual number of exported used televisions and annual television energy use over time. The model shows that the scale of energy usage is highly dependent on the number of exported televisions and their second lifetime. Assuming the number of exported used units to average 15% and be in a range of between 5% and 25% of annual EU sales, an indicative estimate of the energy use of exported televisions is found to be 8.1% (range: 2.7% - 13.6%) of the annual energy use of EU television stock in 2013. Similarly, the annual energy use of exports is estimated to be 26.9% (range: 9.0% - 45.0%) of new EU sales energy use in 2013. Using the model results it can be deduced that Ecodesign regulations first impact the used goods market after the average EU lifetime for the televisions, taken as 9 years in this study. Full savings are expected to be achieved at the global level after the second lifetime in the developing world, assumed to be an additional 5 years in this case (i.e. 14 years total). Further positive effects of Ecodesign regulation at the global level are also discussed, while the model also indicates that the short second lifetimes of used televisions leads to significant WEEE generation in developing countries.
The Federal Institute for materials research and testing (BAM)in cooperation with the Fachhochschule Münster has developed a new certified polymeric reference material, BAM-H010. The reference material consists of acrylonitrile–butadiene–styrene terpolymer (ABS) and has been doped with different contents of the elements Br, Cd, Cr, Hg and Pb. The monitoring of these elements is demanded in the EU directive 2002/95/EG, commonly referred to as RoHS. We have shown that the uncertainty contribution of the thermal long-term stability (ustability) is negligible compared to the contribution to the uncertainty caused by the method used for the characterization of the elemental content and the batch inhomogeneity (uhomogeneity). The stability of theABS material during exposure of the samples with hard X-radiation leads to a degradation of the ABS matrix with either long- or short-chain products.