ABSTRACT

With the advent of the Iron Age, people began learning in earnest how to construct

furnaces that could withstand sustained temperatures exceeding the melting point of

iron (15358C). At the melting point of iron, magnetite (Fe3O4) can be reduced to iron at an oxygen partial pressure of about 1027 atmospheres-an atmosphere

easily reached in a furnace packed with a form of carbon such as coke or charcoal.

Of course, carbon-saturated iron has a melting point of 11528C, but the iron must be at a higher temperature to attain sufficient fluidity for casting.