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due reaction between SiO and SiC. Small amount of slag was noticed on the outer part of the
furnace, in the co-called inactive zone.
In 50 FeSi furnace one zone of loose charge material from the charge top and down to the
electrode tip position was seen. On the outside of the electrodes, from bottom to the top of the
charge was massive slag layer. In addition, a more than 1m high slag layer was present
covering the entire bottom. In some areas, slag layer was deposited 0.5 higher than electrode
tip. This slag layer contained Ca-Al-silicates but was also spiced with small SiC particles. All
slag samples investigated contained quite some carbon from the SiC. Presence of condensates
layer in the upper part of the furnace or SiC crust around electrode tip was not observed.
Furnace charge was very easy to remove, it was running out of the furnace and the material
looked more like a coal bed, than a cavity operation.
Figure 8:
Materials found in 75FeSi: a) reacted charge, b) SiC crust.[2]
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