As the liquid iron rolled over and over in the converter, the silicon and manganese in it were oxidized first after which it was the turn of the carbon in the pig iron.
At a temperature of nearly 1,500 degrees, the carbon reacted with the oxygen in the air, producing carbon monoxide and a lot of heat which made the liquid boil in the furnace. The flames gushing out of the furnace mouth almost enveloped the blowing pipe and the grate. That was why Roland made them coated with heat resistance coating.
