United States
Environmental Protection
Agency
Air and Energy Engineering
Research Laboratory
Research Triangle Park NC 27711
Research and Development
EPA/600/S7-86/054 May 1987
&EPA Project Summary
Gray Iron Foundry Industry
Paniculate Emissions: Source
Category Report
John Jeffery, Joh
i Fitzerald, and Paul Wolf
The objective o this study was to
develop particular emission factors
based on cutoff si :e for inhalable par-
ticles for the gray ir on foundry industry.
After a review of a vailable information
characterizing pa ticulate emissions
from gray iron four dries, the data were
summarized and ra ted in terms of reli-
ability. Size speci ic emission factors
were developed f re m these data for the
major processes u ted in the manufac-
ture of gray iron. A detailed process
description was | resented with em-
phasis on factors J ffecting the genera-
tion of emissions. A replacement for
Section 7.10 (Gra i Iron Foundries) of
EPA report AP-42, A Compilation of
Air Pollutant Emi sions Factors, was
prepared, contain! ig the size specific
emission factors d iveloped during this
program.
This Project Surr maty was developed
by EPA's Air and Energy Engineering
Research Laboratory, Research Triangle
Park, NC, to announce key findings of
the research project that Is fully docu-
mented In a separate report of the same
title (see Project Report orde/fng In-
formation at back). .
Introduction I
The purpose of this prograijn was to
summarize the best available information
on emissions of inhalable particulate
matter in the gray iron foundry industry.
The main objective of the program was to
develop reliable size-specific emission
factors for the various processes used in
the production of gray iron. Both uncon-
trolled and controlled emission factors
are presented in the report. The.uncon-
trolled factors represent emissions which
would result if the particulate control
device (baghouse, ESP, etc.) were by-
passed, and the controlled factors repre-
sent emissions emanating from a
particular type of control system. The
size-specific emission factors are gen-
erally based on the results of simulta-
neous sampling at the inlet and outlet of
the control device(s), utilizing a variety of
particle sizing techniques. Other objec-
tives of this program were to present
current information on the gray iron
foundry industry as well as prepare a
replacement for Section 7.10 in EPA re-
port AP-42, A Compilation of Air Pollutant
Emissions Factors.
The above objectives were met by a
thorough literature search which included:
• Data from the inhalable particulate
characterization program.
• Fine Particle Emissions Inventory
System (FPEIS).
• AP-42 background file at EPA's
Office of Air Quality Planning and
Standards (OAQPS).
• State and local air pollution control
agencies.
• Various industry sources (e.g.,
American Foundrymen's Society).
The emission data contained in the
reference documents were reviewed,
analyzed, summarized, and ranked ac-
cording to the criteria established by
OAQPS as published in the EPA report,
"Technical Procedures for Developing
AP-42 Emission Factors and Preparing
AP-42 Sections," April 1980. After rank-
ing the data, emission factors were cal-
culated using the highest quality data
available. The quality of the data used to
develop each emission factor is indicated
by the emission factor rating.
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Process control system operating data
as well as general industry information
were also obtained and summarized as
general background information. It was
not part of this program to provide detailed
engineering analyses, product specifica-
tions, or detailed evaluation of trends in
the industry.
Summary of Results
Gray iron foundries produce gray iron
castings by melting, alloying, and molding
scrap iron, pig iron, and foundry returns.
The four major production steps are: raw
materials handling and preparation, metal
melting, mold and core production, and
casting and finishing.
Emissions from the raw materials
handling operations consist of fugitive
particulate matter generated from the
receiving, unloading, storage, and con-
veying of raw materials. These emissions
are controlled by enclosing the major
emission points (e.g., conveyor belt trans-
fer points) and routing air from the en-
closures through fabric filters or wet
collectors.
During melting in ah electric arc fur-
nace, particulate emissions are generated
by the vaporization of iron and the trans-
formation of mineral additives. These
emissions occur as metallic and mineral
oxides. The highest concentration of
furnace emissions occurs during charging,
back-charging, alloying, slag removal, and
tapping operations, when the furnace
lids and doors are opened. Generally,
these emissions escape into the furnace
building or are collected and vented
through roof openings. Emission controls
during the melting and refining operations
usually involve venting the furnace gases
and fumes directly to a control device.
Controls for fugitive furnace emissions
include canopy roof hoods or special
hoods near the furnace doors and tapping
hoods to capture emissions and route
them to emission control systems. High
energy scrubbers and baghouses (fabric
filters) are used to control particulate
emissions from cupolas and electric arc
furnaces. Because induction furnaces
emit negligible amounts of hydrocarbons
and carbon monoxide (CO) emissions,
and very little particulate matter as
compared to cupola and electric arc
furnaces, they typically are uncontrolled.
The major pollutant emitted from mold
and core production is particulate matter.
The particulate emissions are generated
from sand reclaiming, sand preparation,
sand mixing with binders and additives,
and mold and core forming. Baghouses
and high energy scrubbers are generally
used to control particulate matter from
mold and core production.
Particulate emissions are also gen-
erated during the treatment and inocula-
tion of molten iron before pouring. For
example, during the addition of mag-
nesium to molten metal to produce ductile
iron, the reaction between the magnesium
and molten iron is very violent and ac-
companied by emissions of magnesium
oxides and metallic fumes. Emissions from
pouring consist of hot metal fumes, CO,
organic compounds, and particulate mat-
ter evolved from the mold and core
materials when contacted with the molten
iron. Emissions from pouring are normally
captured by a collection system and
vented, either controlled or uncontrolled,
to the atmosphere. Emissions continue
to evolve as the molds cool. A significant
quantity of particulate emissions are also
generated during casting shakeout. These
emissions are typically controlled by
either high energy scrubbers or bag filters.
Finishing emits large coarse particles
during the removal of burrs, risers, and
gates, and during shot blast cleaning.
Particulate emissions from finishing are
easily controlled by cyclones and bag-
houses.
The total mass controlled and uncon-
trolled emission factors for gray iron
furnaces are presented in Table 1. Total
mass emission factors for ancillary pro-
cess operations and fugitive sources are
presented in Table 2. The size-specific
controlled and uncontrolled emission
factors are presented in Table 3.
Table 1. Emission Factors For Gray Iron Furnaces9
Process Control device
Total Emission
particulate factor
kg/Mg Ib/ton rating
Cupola
Electric arc furnace
Electric induction furnace
Reverberatory
Uncontrolled
Scrubber
Venturi scrubber
Electrostatic precipitator
Baghouse
Single wet cap
Impingement scrubber
High energy scrubber
Uncontrolled
Baghouse
Uncontrolled
Baghouse
Uncontrolled
Baghouse
6.9
1.6
1.5
0.7
0.3
4.0
2.5
0.4
6.3
0.2
0.5
0.1
1.1
0.1
13.8
3.1
3.0
1.4
0.7
8.0
5.0
0.8
12.7
0.4
0.9
0.2
2.1
0.2
C
C
C
E
C
B
B
B
C
C
D
E
D
E
"Expressed as weight of pollutant/weight of gray iron produced.
Table 2. Particulate Emission Factors For Ancillary Process Operations And Fugitive
Sources At Gray Iron Foundries"
Total emission factor
Process
Scrap and charge handling, heating
Magnesium treatment
Inoculation
Pouring, cooling
Shakeout
Cleaning, finishing
Sand handling
Core making, baking
Control device
Uncontrolled
Uncontrolled
Uncontrolled
Uncontrolled
Uncontrolled
Uncontrolled
Uncontrolled
Scrubber
Baghouse
Uncontrolled
kg/Mg
metal
0.3
0.9
1.5-2.5
2.1
1.6
8.5
1.8
0.023
0.10
0.6
Ib/ton
metal
0.6
1.8
3-5
4.2
3.2
17
3.6
0.046
0.20
1.1
'Expressed as weight of pollutant/weight of gray iron produced.
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Tab/8 3. Particle Size Distribution Dai
Particle
Source size
him)
Cupola Furnace
Uncontrolled
Controlled by baghouse
Controlled by venturi
scrubber
Electric arc furnace
Uncontrolled
Pouring, cooling
Uncontrolled
Shakeout
Uncontrolled
0.5
1.0
2.0
2.5
5.0
10.0
15.0
0.5
1.0
2.0
2.5
5.0
10.0
15.0
0.5
1.0
2.0
2.5
5.0
10.0
15.0
1.0
2.0
5.0
10.0
15.0
0.5
1.0
2.0
2.5
5.0
10.0
15.0
0.5
1.0
2.0
2.5
5.0
10.0
15.0
fa and Emissiot
Cumulative
mass%
< stated size
44.3
69.1
79.6
84.0
90.1
90.1
90.6
100.0
83.4
91.5
94.2
94.9
94.9
94.9
95.0
100.0
56.0
70.2
77.4
77.7
77.7
77.7
77.7
100.0
13.0
57.5
82.0
90.0
93.5
100.0
—
19.0
20.0
24.0
34.0
49.0
72.0
100.0
23.0
37.O
41.0
42.0
44.0
70.0
99.9
100.0
i Factors For Gray Iron Fou
Cumulative mass
emission factor
kg/Mg metal Ib/ton metal
3.1
4.8
5.5
5.8
6.2
6.2
6.3
6.9
0.33
0.37
0.38
0.38
0.38
0.38
0.38
0.4
0.84
1.05
1.16
1.17
1.17
1.17
1.17
1.5
0.8
3.7
5.2
5.8
6.0
6.4
—
0.40
0.42
0.50
0.71
1.03
1.51
2.1
0.37
0.59
0.66
0.67
0.70
1.12
1.60
1.60
6.1
9.5
11.0
11.6
12.4
12.4
12.5
13.8
0.58
0.64
0.66
0.66
0.66
0.66
0.67
0.7
1.7
2.1
2.3
2.3
2.3
2.3
2.3
3.0
1.6
7.3
10.4
11.4
11.9
12.7
—
0.80
0.84
1.00
1.43
2.06
3.02
4.2
0.74
1.18
1.31
1.34
1.41
2.24
3.20
3.20
ndries*
Emission
factor
rate
C
E
C
E
D
E
'Expressed as weight of pollutant/weight of metal melted (produced). Dash = no data.
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J. Jeffery, J. Fitzgerald, and P. Wolf are with GCA/Technology Division, Inc.,
Bedford, MA 01730.
Dale L. Harmon is the EPA Project Officer (see below).
The complete report, entitled "Gray Iron Foundry Industry Paniculate Emissions:
Source Category Report," (Order No. PB87-145 702/A S; Cost: $13.95, subject
to change) will be available only from:
National Technical Information Service
5285 Port Royal Road
Springfield. VA 22161
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
--' !" -*-•>.•-U. • • .;;. '
Official Business
Penalty for Private Use $300
EPA/600/S7-86/054
0000329 PS
AGENCT
CHICAGO
IL
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