Either natural gas or coal can be used to remove the oxygen
from iron ore in order to produce a scrap substitute. In gas-based
processes, the iron ore is heated in a vessel as reformed
natural gas passes through. In coal-based processes, iron
ore is combined with gasified or ground coal and heated. The
oxygen in the ore combines with carbon and hydrogen in the
gas or coal, producing reduced, or metallic, iron.
Heat-resistant brick. Because its melting point is well above
the operating temperatures of the process, refractory bricks
line most steelmaking vessels that come in contact with molten
metal, like the walls of the blast furnace, sides of the ladles,
and inside of the BOF.
Reinforcing Bar (Rebar)
A commodity-grade steel used to strengthen concrete in highway
and building construction.
The process of replacing the refractory lining of a liquid
steel vessel. Once it wears out, the brick lining of a furnace
must be cooled, stripped and replaced. This maintenance can
be significant because a blast furnace reline may require
up to three months to complete.
The impurities in mini-mill steel as the result of the mix
of metals entering the process dissolved in obsolete scrap.
Residuals are key concerns regarding the mini-mills' recent
entry into the flat-rolled market, where high residuals can
leave sheet steel too brittle for customer use.
The stand of rolls used to reduce steel sheet or plate by
passing the steel back and forth between the rolls; the gap
between the rolls is reduced after each pass.
Round, thin semi-finished steel length that is rolled from
a billet and coiled for further processing. Rod is commonly
drawn into wire products or used to make bolts and nails.
Rod trains (rolling facilities) can run as fast as 20,000
feet per minute
Roll Force Systems
Mill stands place considerable pressure on slabs, blooms and
coils to further process the material. There are two general
ways of applying the force to the steel
SCREW (INCLINE PLANE) This older
method used the basic principle of the screw to adjust the
space between the mill rolls. Because metal touches metal,
these configurations will wear down over time and can cause
HYDRAULIC (PANCAKE CYLINDER)
This modern system uses fluid pressure to rapidly adjust the
roll spacing several times per second. These minute, instantaneous
adjustments allow for superior gauge tracking and higher-quality