Programm Photovoltaik Ausgabe 2008 ... - Bundesamt für Energie BFE

Département fédéral de l’environnement,
des transports, de l’énergie et de la communication DETEC
Office fédéral de l’énergie OFEN
SILICON RECYCLING FROM WAFERING
WASTE TO PRODUCE REUSABLE
PHOTOVOLTAIC FEEDSTOCK
FEASABILITY STUDY
Annual Report 2007
Author and Co-Authors Dimitrov Anne, Hoffmann Patrik, Nasch Philippe
Institution / Company EIG / EPFL / Applied Materials
Address Rue de la Prairie 4, 1202 Genève
Telephone, E-mail, Homepage +41 22 54 62 498, anne.dimitrov@hesge.ch
Project- / Contract Number CTI 8829.2 PFIW-IW
Duration of the Project (from – to) 6 months (April 2007 – december 2007)
Date 7 december 2007
ABSTRACT
The objective of the SIRE project was the demonstration of a process that allows the recycling of 80%
of the silicon saw residues contained in exhausted wire-saw cutting slurries from the production of
silicon wafers for the photovoltaic (PV) industry. During the slicing of silicon blocks into thin wafers
(150-200 micron thick) by multi-wire slurry sawing (MWSS) technology, around 50% of the silicon (or
about 3 tons of silicon per MW produced PV power at 15% module efficiency), that entered the wafering
process, is lost in form of fine, micron sized silicon powders which accumulate in the wire sawing
slurries.
The operating conditions in laboratory tests have been developped and it was shown that silicon can
be separated from silicon carbide in artificial mixtures as well as in real industrial waste samples.
Process for Intellectual Property protection of the invention is ongoing.
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