One development that the entire
iron mining industry in North America is watching closely is a
plan by Indias Essar Steel Ltd. to resume iron pellet
production on Minnesotas Mesabi Rangeand using the
taconite pellets to make steel in Minnesota rather than
shipping them to a blast furnace elsewhere.
Essar Steel, which purchased
Canadas Algoma Steel Inc. for $1.6 billion in 2007, is
rehabilitating a long-closed taconite processing plant near
Nashwauk, Minn., with plans to make 6.5 million tons of iron
pellets annually. Essar told analysts that for the foreseeable
future it will ship pellets to the Essar Steel Algoma Inc.
steelmaking complex near Sault Ste. Marie, Ontario, but the
company hopes to begin making steel in Minnesota by 2015.
Sustainability in metals
processing is all about two things: Controlling the energy
inputs in processing to reduce the carbon footprint, and making
end-use metals that are lighter, stronger and harder.
Richard J. Fruehan, co-director
of Carnegie-Mellon Universitys Center for Iron and Steel
Research in Pittsburgh, pointed out that the steel industry has
made several giant leaps in processing technology. The biggest
change, he said, was the adoption of continuous casting. "You
saved energy with continuous casting because the ratio of steel
produced to steel shipped was reduced." Continuous casting also
helped eliminate primary rolling mills, thereby reducing even
more energy inputs. The second most significant advancement in
steel processing was the advent of thin-slab casting, Fruehan
Further downstream, researchers
are looking at ways to harden and lighten steel. Yung C. Shin,
professor of advanced manufacturing in the School of Mechanical
Engineering at Purdue University in West Lafayette, Ind., is
part of a team that has developed and demonstrated the
capabilities of selective laser hardening of various steels.
Precisely controlled laser hardening can increase the hardness
of steel parts at selected areas to a theoretical maximum
value. So far, the process has been shown to work well with
various complex geometries, such as gears, crankshafts and
splines, he said.
The process involves no
induction coils or coolants, making it more environmentally
benign than more traditional hardening processes. "Laser
hardening is a dry process," Shin said. "In more traditional
hardening, companies pay a lot of money for oil for quenching
the parts. They also have to pay for the disposal of the used
Other researchers are looking at
innovative ways to make steel more environmentally friendly.
Researchers at Worcester Polytechnic Institute in Massachusetts
and the Kroll Institute for Extractive Metallurgy at the
Colorado School of Mines are seeking environmentally friendly
ways to reclaim spent foundry sand.
Foundries use clean, uniformly sized, high-quality silica or
lake sand bonded to form molds for ferrous and nonferrous metal
castings. About 1 ton of foundry sand is used in the production
of each ton of iron or steel castings. Researchers estimate
that 10 million to 15 million tons of foundry sand is used and
discarded in the United States each year. Finding a way to
recover much of that sand could eliminate the need to quarry
additional quantities of new sand each year.