10 07 29 Master thesis Juliana Leon - e-Waste. This guide

city. Scrap metal dealers are then working as an interface between the informal and
the formal sector. This business model has the benefit that it is contributing to
prevent informal treatment of a big amount of PWBs; however, by buying only
valuable parts they encourage informal dismantling upstream and improper dumping
of non-valuable parts.
Although site visits could not confirm it, some stakeholders gave indications that
alchemical processes are being employed in backyards, small workshops, or rural
houses. According to Mr. Jaramillo from CI Recycables, this informal practice has
been growing in the country’s main cities and became important in the last 3-4 years
at the point that it is actually a competitor for the enterprise’s activities especially in
Medellín, Bogotá, and Bucaramanga. He estimates that in 2009 around five tons per
month of PC processors and PWBs stayed in the hands of artisanal “recyclers”
(Jaramillo, 2010).
Cable burning seems to be a very common practice in Colombian cities where it is
often performed by recicladores or intermediaries in non-frequented streets,
unconstructed lands, or in backyards (Uribe et al., 2009 and Uribe et al., 2010). Out
of the 52 recicladores, intermediaries, or scrap metal dealers interviewed, only 6
affirmed to strip the cables with a knife instead of burning it. Moreover, scrap metal
dealers do not make any distinction between burned or non-burned copper from
cables when buying copper. Only less than half of the scrap metal dealers accept still
coated cables.
3.4 Material Flow Analysis
3.4.1 Definition of the system
The reality is far too complex to correctly quantify the flows between all the actors
and processes that occur. Hence, the system to be modelled needs to be simplified,
especially regarding the number of processes and flows that are taken into
consideration. The simplification and the definition of the system is an iterative
process during the whole study that depends also on the available data. In this case,
a simplification was to merge some of the disposal and recycling processes together
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