United States
Environmental Protection
Agency
Air and Energy Engineering
Research Laboratory
Research Triangle Park NC 27711
Research and Development
EPA/600/S2-86/078 Jan 1987
&EPA Project Summary
Air Pollution Impacts when
Quenching Blast Furnace Slag
with Contaminated Water
Gopal Annamraju and P. J. Schworer
A potential alternative to treatment prior
to discharge of coke plant waste waters is
to use it, untreated, to quench blast fur-
nace slag. The question arises, will this re-
sult in a significant increase in emissions
to the atmosphere? To develop preliminary
answers to this question, six emission
measurements were made on a laboratory-
scale facility simulating typical slag
quenching practice. Test parameters en-
compassed two slag temperatures (594
and 816°C) and two waters, ASTM Type
1 water and coke plant effluent diluted to
2500 mg/l TDS. The results indicate that
particulate emissions increase with slag
temperature and TDS in the water. Minor
quantities of organic compounds were
emitted but showed no correlation with
test variables. The data also showed no
correlation between emissions of sulfur
dioxide or fluoride and test variables.
This Project Summary was developed
by EPA's Air and Energy Engineering Re-
search Laboratory, Research Triangle Park,
NC, to announce key findings of the re-
search project that is fully documented in
a separate report of the same title (see Pro-
ject Report ordering information at back).
Introduction
This report describes the results of an
experiment conducted to evaluate the im-
pact of atmospheric emissions from
quenching blast furnace (BF) slag with
contaminated water. This work is a contin-
uation of similar work reported in
EPA-600/2-84-072 (NTIS PB84-172493)
in March 1984. The work involved an
assessment of atmospheric emissions
from quenching of BF slag with BF
blowdown water.
This study involved a laboratory scale
assessment of simulated slag quenching
in a specially designed pot partially filled
with fresh molten slag, reheated in a
propane-fired furnace, and quenched with
BF blowdown water. This study revealed
a direct relationship between the content
of total dissolved solids (TDS) in the
quench water and the resultant level of
particulate emissions. A direct relationship
was also found between the slag tempera-
ture and particulate emission rates. Based
on the limited data obtained in this work,
no correlation could be drawn between
slag temperature or level of specific con-
taminants in the quench water and the
resulting air emissions of that contami-
nant. The purpose of the current assign-
ment was to expand the data base by
measuring atmos-pheric emissions during
BF slag quenching with very clean water
and with contaminated water. Laboratory
scale equipment assembled for the
previous study was used in this study.
Slag was poured into the slag pots at
the BF and transported to the experimen-
tal furnace. Blowdown water was obtained
from another BF with a moderately tight
recycle system and transported to the
laboratory in 5-gal. (18.9 liter) jars. Coke
plant wastewater obtained from a coke
plant was diluted to =2500 mg/liter of
TDS and used for quenching. ASTM Type I
water with low TDS and no organics was
used as a baseline for comparison. Six test
runs were conducted at two different
ranges of slag temperature. These tests
provided a qualitative estimate of emis-
sions under different slag temperatures
and the effect of the use of different types
of water on these emissions.
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Conclusions
Major findings and conclusions of the
study included:
1. Particulate emissions, measured by
the front half of the modified SASS
train during BF slag quenching, in-
crease with increasing slag temper-
ature. The higher the TDS in the
quench water, the more pronounced
the increase becomes.
The estimated regression line equa-
tions for low and high slag temper-
ature quench are:
y = 53.5 + 0.0495 x
(for low temperature = 594°C)
y = 30.38 + 0.14779 x
(for high temperature = 816 °C)
where, x is the TDS content of the
quench water and y is the particulate
emissions (mg/liter of quench water
evaporated).
2. Based on this laboratory-scale simu-
lation, for coke plant wastewater
containing a comparable TDS con-
tent as that of BF blowdown water,
the emissions generated during slag
quenching at high temperature are
considerably less using coke plant
water than when using BF blowdown
water. The pollutants present in the
coke plant water appear to break
down at high-temperature slag
quenching and result in less par-
ticulate emissions.
3. Emissions of metals increase with
high-temperature slag quenching.
4. No specific relationship was found
between organic pollutants and the
use ofASTM type I water or BF blow-
down water, and slag temperature
during quenching.
Significant amounts of priority pollu-
tants were dissociated from the coke
plant wastewater at both low- and
high-temperature slag quenching,
when all the applied water was
evaporated.
5. No correlation was found between
quench water quality, slag tempera-
ture, or slag sulfur content and emis-
sions of sulfur dioxide.
6. Chloride emissions are higher at high-
temperature slag quench. The emis-
sions are higher if the quench water
contains higher chloride concentra-
tion.
7. Cyanides appear to dissociate a
both low- and high-temperature s/a
quenching with BF blowdown wate
8. Ammonia appears to break down i
higher-temperature quenching. Th
ammonia emissions are higher if th
quench water contains higher an
monia concentrations.
9. Fluoride emissions are higher i
higher-temperature slag quenchin
and they bear no relationship to th
quench water quality.
G. Annamraju and P. Schworer are with PEI Associates, Inc., Cincinnati, OH
45246-0100.
Robert C. McCrillis is the EPA Project Officer (see below).
The complete report, entitled "Air Pollution Impacts when Quenching Blast
Furnace Slag with Contaminated Water,"(Order No. PB87-100 533/AS; Cost.
$11.95, subject to change) will be available only from:
National Technical Information Service
5285 Port Royal Road
Springfield, VA22161
Telephone: 703-487-4650
The EPA Project Officer can be contacted at:
Air and Energy Engineering Research Laboratory
U.S. Environmental Protection Agency
Research Triangle Park, NC 27711
United States
Environmental Protection
Agency
Center for Environmental Research
Information
Cincinnati OH 45268
Official Business
Penalty for Private Use $300
EPA/600/S2-86/078
SMBSC
CHICAGO
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