The application of prerefining for steelmaking processes

MANY PROCESSES have been developed for the pretreatment
of pig iron before its final refining in open-hearth furnaces. At the turn of this century the 'washed metal'
process, deVeloped in 1890 by Campbell,' was used in
the USA to remove silicon and phosphorus from pig iron
before final steelmaking in the acid open-hearth process.
About this time the Bertrand Thiel process,2 Hoesch and
Talbot processes3 and the Monel process" were developed.
These processes were chemically attractive, but were
abandoned because of excessive iron losses due to chill-
ing and difficulties in the maintenance of the refractor-ies in the vessels utilized. However, the advantages of working with prerefined metal of known and regular comp-osition were proved inasmuch as the processes were flexi-ble and variations in technique could be employed to suit
variable conditions. The heat developed during prerefining
can be utilized either to melt up unwieldy pit scrap or, alternatively, ore can be used to control temperature
with an attendant useful gain in yield.