The aviation
industry is constantly evolving so that it can design lighter aircrafts, reduce
consumption/emissions and put in place more efficient recycling systems that
allow reusing the valuable materials used in their construction.
The European project SENTRY is part of the ambitious “Clean
Sky” program. An outstanding public-private partnership between the European
Commission (EC) and the aircraft industry, established to bring significant
step changes and improve the environmental impacts of aviation.
In this
project, the “End of Life Analysis” of three panels of aircraft fuselage has
been conducted. The fuselage is produced by different new generation aluminum
alloys which are rich in specific alloying elements, such as lithium or silver,
and covered by different defensive layers that protect them against corrosion and
other types of external aggressions.
Lithium is
the lightest metal existing element in nature and its cost is about 30 times higher
than aluminum. It is a highly oxidizable and volatile element so it is
necessary to follow strict guidelines on recycling, which are not common in
other aluminum alloys. The SENTRY project proposes the development of an
efficient recycling technology of these alloys, trying to accomplish an
integral exploitation of all the lithium content from them.
Furthermore,
the elimination of the protective layers, which is the 4% by weight on the
metallic material, must be accomplished through environmentally sustainable
methods, avoiding the addition of impurities that reduce the quality of the recycled
aluminum obtained.
The current
recycling scenario used as a reference in the SENTRY project, involves the
indiscriminate mixing of alloys. This generates a dilution of alloying elements
(Li, Ag, etc) in the aluminum, preventing possible re-use with its initial
concentration value. Under these conditions the reuse can only be done at low
dilutions and as very poor quality aluminum.
The SENTRY
project is aimed to carry out a specific recycling process of alloys used to
manufacture aircraft panels from the fuselage, so that the materials used do
not get diverted towards products of lower value and are liable to be used again
in manufacturing of high quality aeronautic alloys and reincorporated into the
original application. To reach these ambitious objectives a new scenario of
dismantling, compatible alloy sorting, coating removal and recycling is
proposed.
IK4-Azterlan
has taken an active role in optimizing processes, both from the removal of
protective coatings and from the efficient recycling of metal alloys,
especially the ones alloyed with lithium.
The project,
already in the final stage of implementation, has successfully fulfilled the main
objectives set out previously:
- The
panels have been dismantled effectively, sorting materials according their
alloys.
- Coatings
have been removed successfully minimizing to the maximum the environmental
impact of these operations.
- Finally, the alloys have been recovered and especially lithium alloys,
with high recycled yields and minimal losses of critical elements.
No hay comentarios:
Publicar un comentario