In the paper "Summary: Technological Innovation" authored by F. Bonmo, in the
book "The Steel Industry in the New Millennium", the author summarized general
development of the steel industry in recent years and the future trends. Some
points of the paper are abstracted in this article.
Strong competition is taking place between the traditional concept of
steelmaking based mainly on integrated works and the present trend towards mini
mill production. This competition has significantly accelerated manpower
reductions in the iron and steel industry that were already taking place due to
technical improvements. For example, the labor required to make cold rolled
sheet has gone down from about 10 man hours per ton at the end of the 1970s to
the current 3-4 man hours per ton at an integrated works, and less than one man
hour per ton at the most recent mini mills.
Mini-Mill and Related Technologies
Competition from mini mills is very active due to the following issues:
- Lower specific investments and much lower total investment needed,
allowing newcomers to enter the business. This has helped bring about the
collapse of the past structure of the industry;
- The mini mills advantage of lower man hours per tonne of product;
- The opportunity to locate production units near steel users;
- Greater flexibility of the mini mill route;
- Lower environmental impact.
A further incentive to the spread of mini mills is the recent development of
important new technologies more suitable for application in mini mills as
compared with conventional integrated plants. In particular, the following
technologies have to be mentioned:
- melting reduction using the Corex process from VAI. By avoiding the use of
coke, Corex makes it possible to save the investment costs of coke ovens.
- Thin slab technology for hot strip production. Examples discussed here
include CSP from SMS and ISP by MDH/Arvedi. By using direct rolling and lower
thickness slabs, reheating furnaces can be saved. A temperature homogenization
furnace can be used in place of a reheat furnace. The length of the rolling
train is reduced as less reduction is required from a thin slab.
- Continuous linking of downstream pickling and cold rolling allow the
production cycle to be further compacted.
Important technological steps are expected in the near future. For example,
second generation smelting reduction should allow, not only the substitution of
coke with coal, but also the use of fine ore in place of lump ore. In this way
it will be possible to eliminate sinter plants used to agglomerate fine ores in
existing integrated works. Successful development of strip casting can be
anticipated. Casting steel strip directly will get rid of the rolling process.
This would allow a great saving on the transformation cost. Above all it would
save on the huge capital investment in hot strip mills.
The electric arc furnace is at the heart of the competition between megamills
and mini mills. The EAF is more suitable than other liquid steel sources for the
simple, flexible and compact' concept, at least in the short to medium
term. EAF steelmaking might reach a share nearer to 50 per cent by the year
The growing importance of the electric arc furnace has given rise to rapid
technological progress. In the past decade there have been remarkable savings in
energy, refractory use and electrode consumption coupled with significant
improvements in productivity. Recent major innovations in electric steelmaking
have aimed to reduce environmental impact, to further improve energy savings and
productivity, and to diversify the charge material. The following technologies
- Twin shell furnaces;
- continuous charging and preheating of scrap;
- Oxygen and carbon injection and post-combustion technologies, allowing
substitution of electrical energy with less expensive chemical energy.
It is recognized that increased electric arc furnace utilization is linked to
availability of ferrous charge material, at the moment mainly scrap. This
focuses attention on the scrap problem: either there is enough scrap to meet the
likely higher demand, or its price will increase to the point where electric arc
steel will become far less competitive relative to integrated steel production.
If scrap prices increase, electric arc steel output will not reach the high
level forecast for the year 2010. Scrap substitutes play an important role in
the overall picture. These include directly reduced iron (DRI) and ordinary iron
(either hot metal or cold pig iron). Development of new directly reduced
ironmaking technologies, like FINMET and others, may significantly decrease the
cost of DRI to the point where it could become competitive with the scrap price,
even in places where energy costs are currently too high for economic
production. In this event, the forecast for future electric arc production could
well be realized. Substitutes for scrap will play an important role as a
supplementary charge material in any event. Some high purity charge material is
required to dilute residuals in scrap. The spread of mini mills for flat
products increases the importance of scrap substitutes as a pure charge
material. Even if scrap supplies are readily available, some alternative charge
material will be required for quality reasons.
This general scenario does not apply with equal force in different
geographical regions. Perhaps scrap will not be a problem in the older
industrialized areas such as the USA, the European Union and Japan. Whereas a
shortage can be envisaged in the emerging industrialized economies, especially
in Asia. For example, South Korea, China, Taiwan and India are likely to
experience scrap deficits. Scrap substitutes are likely to be widely used in
these countries. Current examples include production of hot iron from COREX in
South Korea, pig iron from small blast furnaces in China and coal based DRI in
The impact of the emerging alternative iron-modern electric arc
steelmaking technologies on existing plants is hard to assess. These new
technologies compete with the traditional blast furnace-basic oxygen steelmaking
route and with scrap based electric arc based plants using conventional
continuous casting and rolling technologies. No doubt the most modern or
recently upgraded works will continue producing in the usual way for many years.
It is not economic to replace still efficient plants with new plants since the
extra capital costs cannot be compensated by the flow of lower operating costs.
A few years ago it was thought that coke shortages arising from coke ovens
reaching the end of their lives would result in closure of integrated works.
Reconstruction of coke ovens is expensive. Instead, pulverized coal injection (PCI)
is now routinely used to replace coke in the blast furnace. The technique is
likely to be further used and expanded in the near future. In the longer term
blast furnaces might be replaced by smelting reduction plants. The possibility
of installing more environmentally friendly and technologically advanced coke
ovens cannot be excluded.
Remarkable plant engineering activity can be anticipated over the next few
years. Some forecasts indicate that world steel demand might reach 1000 million
tons a year by the year 2010. Rising demand coupled with a high propensity
towards innovation are expected to trigger a high level of plant construction.
Looking forward, estimates suggest by the year 2010, new plant of about
250-300 million tons annual capacity, and upgrading of existing plants with
a capacity of around 170 million tons a year will be required.
 R. Ranieri and J. Aylen (ed.): The Steel Industry in the New Millennium.
Vol. 1: Technology and Market. 1998. IOM Communications Ltd. ISBN 1-86125-019-3.