The Encyclopedia Americana (1920)/Spiegeleisen
SPIEGELEISEN, spē'g’l-ī''zĕn, a white
cast iron originating in Germany, made from
specular iron ore, or hematite, containing a
large percentage of carbon and manganese.
Being remarkably free from impurities, as phosphorus,
sulphur, silica, it is largely used in the
Bessemer process of steel-making for the
purpose of reintroducing carbon. It reduces the
iron oxide and is itself subject to oxidation.