Socio-economic assessment and feasibility study on - Öko-Institut eV

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August 2010
<strong>Socio</strong>-<strong>economic</strong> <strong>assessment</strong> <strong>and</strong> <strong>feasibility</strong> <strong>study</strong>
on sustainable e-waste management in Ghana
low cost solution for emerging economies (Cui & Zhang 2008), others stress the fact that
hydrometallurgical processes have not yet published comprehensive flow sheets <strong>and</strong> that the
type of processes – using strong acids or caustic solutions – are associated with
considerable risks for human <strong>and</strong> environmental health. A comprehensive overview on the
critical issues of hydrometallurgical refineries is presented in Schluep et al. 2009.
The copper from cables <strong>and</strong> the low grade copper fraction can be sold to secondary copper
refineries. The low grade copper fraction is especially attractive for secondary copper-steel
smelters with a focus on processing mixed steel-copper scrap. Generally, it is beneficial to
remove larger plastic parts to increase the fraction’s purity.
The plastic fraction is mostly composed of ABS <strong>and</strong> Polycarbonates used for cases <strong>and</strong>
structural components. Furthermore, thermosets like epoxy resin are used for PWBs <strong>and</strong> in
coatings <strong>and</strong> housings of electronic components, switches <strong>and</strong> motors. PVC is used for cable
insulations. All these plastic types have in common that they are permeated with flame
retardants. Especially those plastic parts that – during the use-phase of the products – are
exposed to heat usually feature high concentrations of flame retardants.
Generally, the thermosets from PWBs <strong>and</strong> electronic components are strongly interlinked
with the copper <strong>and</strong> precious metals fraction <strong>and</strong> are used as fuel <strong>and</strong> reducing agent in the
metal refining process. The thermoplastics (ABS <strong>and</strong> Polycarbonates) can theoretically be
recycled into new products. Nevertheless, the contamination with flame retardants
significantly reduces the options for secondary applications as with the established recycling
methods these constituents will be part of the new products. For consumer safety reasons,
this is unacceptable for many applications. Furthermore, the secondary use of these
materials will only postpone the end-of-life problem associated with hazardous flame
retardants <strong>and</strong> might lead to the problem of cross-contamination. Especially if used in a wide
range of applications, the subsequent situation of broadly dispersed flame retardants might
be even worse than today, where plastics with flame retardants can easily be identified on
the basis of their original function. Even secondary applications in new electric <strong>and</strong> electronic
devices largely prove infeasible, as the majority of new products are designed to comply with
the European RoHS-Directive strongly limiting the use of the flame retardants PBB <strong>and</strong>
PBDE. Although ongoing research projects aim to identify ways to depolymerise <strong>and</strong> clean
thermoplastics from e-waste (Arends 2009), these techniques are not yet applicable on an
industrial scale. Therefore, one option for the management of plastics from waste computers
is energy recovery in power plants or cement kilns with sophisticated off-gas treatment.
Alternatively, plastics could also be disposed off in engineered l<strong>and</strong>fills for hazardous waste.
As there are currently no cement kilns, waste incinerators <strong>and</strong> engineered l<strong>and</strong>fills located in
Ghana, the implementation of these solutions requires structural investments.