Why do small black balls appear in the lining when it is demolished?

Carbon monoxide produced of the oxidation of the carbon of the metal spreads across the porous zones of the silicon lining where it dissociates itself depositing coal.

2C metal + O2 (air) >2 CO (gas) > C + O2

What can happen?

It does not have effect on the refractoriness of the mass. However, in old or poorly conditioned coils it can cause arches between turns.

What to do?

- Avoid overheating.

- Do not put the graphite into the empty furnace.

- Increase the density of the area by improving material quality and / or vibration.