الفهرس 
CHARACTERIZATION !J." ~ "D TREATABILITY OF IRON AND STEEL WASTESOnly 14 pages are availabe for public view
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Abstract
The continued industrial expansion of our nation is
progressing at an increasing rate due to a number of factors,
such as rising standard of living, more industrial automation
and an increasing population.
Water forms an essential raw material in almost every
industry, though only small fraction of it may appear in the
final product. Most and frequently all of it must be discharged
and is usually contaminated with small amounts of all
materials used in the plant.
New industries, as well as old, are recognizing the
. .
importance of the proper use of water, its storage, removal
of impurities, and the return of clean water to the stream.
Steel industry has long been considered among the largest
of industrial consumers of water. With the possible
exception of some atomic energy plants, an individual steel
mill will probably utilize more water than any other single
industrial plant.
The amount of water used in a steel plant per ton of
finished product varies widely, depending on the quantity
and quality of the available water supply, types of production
facilities, types and distribution of end I
..
Average values for a large integrated steel plant range from
20~000 to 45,000 gal. per ton - (Bowman and Houston, 1966;
Nebolsine, 1967). Actual consumptive use of water, i.e.,
water withdrawn but not returned is probably less than 1000
gal. per ton of product.
A recent industry survey indicated
a maximum water use of 49,000 gal. per ton of product and an
average use of 17,000 gal. per ton - ( Gurl~~ 1964).
Most of the water required by ~ steel plant is used
for indirect cooling, and needs no treatment, provided it
is not excessively hard. Chlorination is often used to
prevent slime formation.
The water used in blast furnace gas washing and in hot
mills for roll cooling and scale transport is not necessa.r:}.ly
of high quality. It is usually used as pumped raw or settled
water.
In the various finishing operations such as cold reduc-
tion, stainless strip rolling, electrolytic tin lines, and
galvanizing pure water is required and thus treated water
is often used.
Of the total amcunt of water used, almost one half is
for the steel making opez-atd.ons , somewhat over one quarter
is needed by the hot m:i_lJ.s?and slightly under one quarter for the steel finishing and auxilliary· oper~t~ons.
In iron and steel production, as in most other branches
of industry, the supply of water constitutes a problem that
grows in magnitude as the industry itself grows.
One of the most effective ways to meet anti-pollution
regulations is to continue reusing water until it disappears.
This is actually being accomplished at the Fontana Steel plant
as described by Riegel (1957). It is true that in ’thisparticular
instance it was the lack of supply that determined
this unusual procedure. The water is passed successively
through a number of systems in an prder that corresponds with
decreasing quality requirements. The final step is to use
the waste to cool the slag and to spray raw materials for
dust control. The result is no final effluent. Reuse, or
recirculatio~ of waste water is not uncommon, but it is rare to
find no final effluent.
Reci~culation vdll generally change the character of the
waste so that in its final form the waste will be more concentrated.
It will decrease the volume of final effluent that
may have to be conditioned. Presumably, this would redu.ce
the cost of treatment, but this is not always the case.
Reuse possesses several advantages in additioh to red-
uci.ng waste and corresponding pollution. These advantages