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Oxidation.
Understanding oxidation is an extensive
part of the effort in RD 3. Refining oxidation during gas
purging of silicon and oxidation of aluminium during
melt treatment are main focus areas. PhD candidate
Erlend Lunnan Bjørnstad has studied the fundamentals
of Ca and Al mass transfer from Si metal to slag. Jan
Erik Olsen and Thorvald A. Engh have also developed
a mathematical description model of silicon refining
during tapping. The studies of PhD candidate Nicholas
Smith into Be as an inhibitor for Al alloy oxidation has
been continued, see more about his research at page
34. Work in 2016 by Martin Syvertsen at SINTEF has also
shown that while 2 ppm Be inhibits oxidation, it does not
affect the strength of the oxide skin. However, at higher
levels (0,3%) it decreases the strength, as shown in the
Figure below.
Figure above shows that Beryllium decreases the oxide strength.
Workshops/Seminars.
On the 12th of April 2016, 24 ex-
perts from industry and research discussed what kind
of- and how much waste and by products, the metal pro-
duction generates. A common understanding between
various metal producers and education/research is cru-
cial to set a direction for future metal production with
the motto “No waste” and “Value added by-products”.
Recycling of post consumed scrap.
In 2016, the SFI
centre invited PhD candidate Stefano Capuzzi from the
University of Padova (Italy) to visit for 4 month. The ti-
tle of his thesis is “Optimzation of the aluminium refing
process”. The work resulted in one paper submitted
to Light Metals and one paper submitted to Journal of
Sustainable Metallugy. The results have also been use-
ful for the industry; in particular for rotary furnace prac-
tice in aluminium recycling.
The figure above shows 100 pieces of coated aluminium that have been
remelted under a salt flux. In the picture to the left the 100 pieces have
been preheated to 400 ºC, and in the picture to the right to 600 ºC.
Recycling and Refining (RD3)
by Senior Research Scientist Anne Kvithyld
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Highlights of 2016 from the Research Domains