During the last decades minimills have achieved a significant share in the
steel market. Their new focus is the production of clean steel, whereby the
application of hot metal as a scrap substitute bears several advantages.
The newly developed compact blast furnace is favourably aimed at the needs
of minimill operators and incorporates up-to-date blast furnace technology.
It has been developed as a medium size, flexible and cost competitive iron
making unit for minimills as well as for integrated steelworks, The furnace
supplies high-quality material that can be charged into electric arc furna
ces either as liquid hot metal or solid pig iron. The major disadvantage of
the conventional blast furnace, its high capital investment cost, has been
removed by reducing each part of the blast furnace to its necessary minimu
m. The main characteristics are found in the free-standing tower constructi
on, the application of copper and nodular cast iron staves inside the compl
ete furnace to minimize the refractory lining, the vertical charging belt c
onveyor and the compact design of the casthouse, stockhouse and hot blast s
toves.
Regarding the application of the compact blast furnace in minimills, scrap
can be substituted by hot metal to a large extent. The energy consumption a
nd the tap-to-tap times can be reduced significantly. In integrated steel p
lants the compact blast furnace represents an additional and flexible ironm
aking unit at low capital investment costs.