Resistance to molten metals and slags

Question 1

What are the characteristics of graphite?

Answer 1

~ it is non-wetting to most molten metals and slags

Question 2

What does graphite do?

Answer 2

~ reduces iron oxide to iron metal, so Fe2O3/Fe3O4 DOESN’T FORM low-melting eutectic liquids with MgO

Question 3

What does CO and or Mg vapor do?

Answer 3

~ formed from oxidation of carbon or reduction of MgO

~ provides an OVERPRESSURE, resists slag/metal ingress