Why does Zn appear against the mica during the demolition of the lining?

The presence of Zn in the demolition is associated with its presence in the used load and with the incorrect melting of the same one in the furnace of induction.

The Zn  volatilizes at 919 ºC going from solid form (of galvanic sheets) to gas. In gas form it penetrates in the pores of the lining and having found its isotherm of solidification at 419 ºC solid form happens again.

What happen?

If coils are in poor condition Zn can be resposible for arches between turns.

What to do?

- Improve the densification of the lining.

- Proceed to change the way fo providing the metallic load. The galvanized package should be introduced once the furnace has enough metal and temperature.