!$<   for Steel Mill Wastes
Recognition, Removal, Reuse
and Research
L. G. KOEHRSEN, Head
Civil Department, Report Group
Stanley Consultants
Muscatine, Iowa
F. G. KRIKAU, Manager
Environmental Control
Interlake Steel Corporation
Chicago, Illinois
INTRODUCTION
A modern fully integrated steel mill is a vast industrial complex. Process and
material handling equipment and systems represent some of the most massive facilities
presently constructed. Similarly, water supply and pollution abatement problems
frequently dwarf those of other industries.
Figure 1 schematically illustrates the various unit operations which may be found
in a modern steel making complex. Basic raw materials, iron ore, coal, and limestone
flow to the plant from the respective mining locations. Ore and limestone funnel
directly to the blast furnace while coal is charged to coke ovens for carbonization.
Metallurgical coke is transported to the blast furnace and by-product coal chemicals
are recovered for separate use or marketing.
Iron leaving the blast furnace either as hot metal or solidified pig iron is charged
to one of the several types of furnaces for conversion into steel. Open hearth furnaces
have for many years been the traditional work horse units of steel manufacturing.
Electric furnaces, normally relatively small units, offer a maximum of flexibility due
to the variety of types of steel that can be produced and the short heat time required.
This type of facility is thus readily adaptable to specialty steel producers.
Within the last 15 years the basic oxygen furnace has taken over an increasing
role in the United States and world wide steel making operations. In 1955 BOF steel
in the United States represented 0.3 per cent of the total domestic production while
by 1966 this had increased to 25.3 per cent or 33,900,000 tons. This increase was
largely countered by a decrease in open hearth steel production from 105,400,000 to
85,000,000 tons (1). A continuation of these trends is certain due to the inherent
economic and production advantages attributable to the basic oxygen process.
Normal operating practice following the steel making furnaces involves pouring
ingots, stripping molds, reheating in soaking pits, and reduction of the ingots to
workable blooms, billets or slabs. Recent technological advances in continuous casting
techniques are now making it possible to bypass these operations and produce slabs or
billets ready for finishing in a single operation.
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