Basic oxygen steelmaking (
BOS,
BOP,
BOF, and
OSM), also known as
Linz-Donawitz- steelmaking or the
oxygen converter process is a method of primary
steelmaking in which carbon-rich molten
pig iron is made into
steel. Blowing
oxygen through molten pig iron lowers the carbon content of the
alloy and changes it into
low-carbon steel. The process is known as
basic because
fluxes of
burnt lime or
dolomite, which are chemical
bases, are added to promote the removal of impurities and protect the lining of the converter.