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center of the furnace caved down approximately 0.5m during the cooling process. Excavation
took place, 5 months after shut down.
Figure 2:
Pictures of furnace 75 FeSi in Finnfjord with marked excavation front.
Elkem Thamshavn. Due to the detection of temperature rise in the bottom lining, the Si
producing furnace was stopped in the beginning of March 2013. The furnace was shut down
without any special considerations, as it was believed that it was only a temporarily shut
down. The furnace was operated at about 40 MW and the total size is 11.3 m and about 4.5 m
high from the shell to the top of the charge. Electrodes were cut before the excavation began,
which made it impossible to observe. The furnace was relined and then restarted as fast as
possible.
Figure 3:
Pictures of furnace in Elkem Thamshavn with marked excavation front.
Elkem Bjølvefosen.The interior of the furnace 1 producing 50% FeSi. Dimension were about
6-7m in inner diameter and 2.8m high. The electrodes were moved after shutdown. This
means first of all, that it was not possible to see if cavities are present or not below the
electrodes. Secondly, it also means that mass from above could be found in the lower part of
the furnace than originally positioned. The charge was hot-glowing (Figure 4) as the
excavation started and this will of course limit the extent of the excavation, in the manner that
samples cannot be exactly positioned.
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