United States
Environmental Protection
Agency
Industrial Environmental Research EPA-600/2-78- 004n
Laboratory May 1978
Cincinnati OH 45268
Research and Development
Source Assessment
Crushed Sandstone,
Quartz, and
Quartzite
State of the Art
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RESEARCH REPORTING SERIES
Research reports of the Office of Research and Development, U.S. Environmental
Protection Agency, have been grouped into nine series. These nine broad cate-
gories were established to facilitate further development and application of en-
vironmental technology. Elimination of traditional grouping was consciously
planned to foster technology transfer and a maximum interface in related fields.
The nine series are:
1. Environmental Health Effects Research
2. Environmental Protection Technology
3. Ecological Research
4. Environmental Monitoring
5. Socioeconomic Environmental Studies
6. Scientific and Technical Assessment Reports (STAR)
7, Interagency Energy-Environment Research and Development
8. "Special" Reports
9. Miscellaneous Reports
This report has been assigned to the ENVIRONMENTAL PROTECTION TECH-
NOLOGY series. This series describes research performed to develop and dem-
onstrate instrumentation, equipment, and methodology to repair or prevent en-
vironmental degradation from point and non-point sources of pollution. This work
provides the new or improved technology required for the control and treatment
of pollution sources to meet environmental quality standards.
This document is available to the public through the National Technical Informa-
tion Service, Springfield, Virginia 22161.
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EPA-600/2-78-004n
May 1978
SOURCE ASSESSMENT:
CRUSHED SANDSTONE, QUARTZ, AND QUARTZITE
State of the Art
by
P. K. Chalekode, T. R. Blackwood, and R. A. Wachter
Monsanto Research Corporation
Dayton, Ohio 45407
Contract No. 68-02-1874
Project Officer
John F. Martin
Resource Extraction and Handling Division
Industrial Environmental Research Laboratory
Cincinnati, Ohio 45268
INDUSTRIAL ENVIRONMENTAL RESEARCH LABORATORY
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
CINCINNATI, OHIO 45268
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DISCLAIMER
This report has been reviewed by the Industrial Environmental
Research Laboratory-Cincinnati, U.S. Environmental Protection
Agency, and approved for publication. Approval does not signify
that the contents necessarily reflect the views and policies of
the U.S. Environmental Protection Agency, nor does mention of
trade names or commercial products constitute endorsement or
recommendation for use.
ii
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FOREWORD
When energy and material resources are extracted, proc-
essed, converted, and used, the related pollutional impacts on
our environment and even on our health often require that new
and increasingly more efficient pollution control methods be
used. The Industrial Environmental Research Laboratory -
Cincinnati (lERL-Ci) assists in developing and demonstrating new
and improved methodologies that will meet these needs both effi-
ciently and economically.
This report contains an assessment of air emissions from
the crushed sandstone, quartz, and quartzite industry. This
study was conducted to provide a better understanding of the
distribution and characteristics of emissions from this industry.
Further information on this subject may be obtained from the
Extraction Technology Branch, Resource Extraction and Handling
Division.
David G. Stephan
Director
Industrial Environmental Research Laboratory
Cincinnati
• • •
111
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PREFACE
The Industrial Environmental Research Laboratory (IERL) of the
U.S. Environmental Protection Agency (EPA) has the responsibil-
ity for insuring that pollution control technology is available
for stationary sources to meet the requirements of the Clean Air
Act, the Federal Water Pollution Control Act, and solid waste
legislation. If control technology is unavailable, inadequate,
or uneconomical, then financial support is provided for the
development of the needed control techniques for industrial and
extractive process industries. Approaches considered include:
process modifications, feedstock modifications, add-on control
devices, and complete process substitution. The scale of the
control technology programs ranges from bench- to full-scale
demonstration plants.
IERL has the responsibility for developing control technology
for a large number of operations (more than 500) in the chemical
and related industries. As in any technical program, the first
step is to identify the unsolved problems. Each of the indus-
tries is to be examined in detail to determine if there is suffi-
cient potential environmental risk to justify the development of
control technology by IERL.
Monsanto Research Corporation (MRC) has contracted with EPA to
investigate the environmental impact of various industries that
represent sources of pollutants in accordance with EPA's respon-
sibility, as outlined above. Dr. Robert C. Binning serves as
MRC Program Manager in this overall program, entitled "Source
Assessment," which includes the investigation of sources in each
of four categories: combustion, organic materials, inorganic
materials, and open sources. Dr. Dale A. Denny of the Industrial
Processes Division at Research Triangle Park serves as EPA Pro-
ject Officer for this series. Reports prepared in this program
are of two types: Source Assessment Documents, and State-of-
the-Art Reports.
Source Assessment Documents contain data on pollutants from
specific industries. Such data are gathered from the literature,
government agencies, and cooperating companies. Sampling and
analysis are also performed by the contractor when the avail-
able information does not adequately characterize the source
pollutants. These documents contain all of the information
necessary for IERL to decide whether a need exists to develop
additional control technology for specific industries.
iv
-------
State-of-the-Art Reports include data on pollutants from
specific industries which are also gathered from the literature,
government agencies and cooperating companies. However, no
extensive sampling is conducted by the contractor for such indus-
tries. Sources in this category are considered by EPA to be of
insufficient priority to warrant complete assessment for control
technology decisionmaking. Therefore, results from such studies
are published as State-of-the-Art Reports for potential utility
by the government, industry, and others having specific needs
and interests.
This State-of-the-Art Report contains data on air emissions
from the crushed sandstone, quartz, and quartzite industry.
This project was initiated by the Chemical Processes Branch of
the Industrial Processes Division at Research Triangle Park;
Mr. D. K. Oestreich served as EPA Project Leader. The project
was transferred to and completed by the Resource Extraction and
Handling Division, lERL-Cincinnati, under Mr. John F. Martin.
v
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ABSTRACT
This report describes a study of air pollutants emitted by the
crushed sandstone, quartz, and quartzite industry. The poten-
tial environmental effect of this emission source was evaluated
using source severity values. Source severity is defined as the
ratio of the maximum ground level concentration of a pollutant
at a representative plant boundary to a hazard factor. The
hazard factor is the ambient air quality standard for criteria
pollutants and an adjusted threshold limit value for other
pollutants.
In 1972, 362 plants in the U.S. produced 24.3 x 106 metric tons
of crushed sandstone, quartz, and quartzite. This accounted for
2.9% of the output of the aggregate industry (crushed limestone,
granite, stone, sand, gravel, sandstone, quartz, and quartzite).
Atmospheric emissions of particulates occur from drilling, blast-
ing, loading and unloading trucks, transport on unpaved roads,
washing, crushing, screening, conveying, and stockpiling. The
emission factor for respirable particulates from processing is
3.6 g/ metric ton, with washing, screening, crushing, and vehic-
ular movement on unpaved roads contributing approximately 80% of
the value. The hazardous constituent of the emitted dust is
free silica. Emission factors for carbon monoxide, nitrogen
oxides, and fibers are 1.68 g/metric ton, 2.85 g/metric ton, and
1,360 fibers/metric ton, respectively.
A representative crushed sandstone, quartz, and quartzite plant
is defined as having a production rate of 454 metric tons/hr and
emitting respirable particulates (less than 7 ym) and total par-
ticulates at the rate of 1.63 kg/hr and 15.7 kg/hr, respectively.
The maximum source severity due to respirable free silica emis-
sions from such a plant is 0.91.
Total particulates emitted from all crushed sandstone, quartz,
and quartzite sources account for 0.005% of the national mass
emissions burden of particulates. The mass of particulate
emissions from such sources is expected to be 1.29 times greater
in 1978 than it was in 1972.
Air pollution control is not widely applied to emissions from
crushed sandstone, quartz, and quartzite operations.
VI
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This report was submitted in partial fulfillment of Contract
No. 68-02-1874 by Monsanto Research Corporation under the spon-
sor of the U.S. Environmental Protection Agency. The study
covers the period March 1975 to July 1977, and the work was com-
pleted in July 1977.
vii
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CONTENTS
Foreword
Preface iv
Abstract vi
Figures x
Tables x
Abbreviations and Symbols ' . xi
Conversion Factors and Metric Prefixes xiv
1. Introduction 1
2. Summary 2
3. Source Description 4
Process description 4
Factors affecting emissions 5
Geographical distribution 6
4. Emissions 9
Selected pollutants 9
Characteristics 10
Definition of a representative Source 10
Source severity and affected population 12
5. Control Technology 15
State of the art 15
Future considerations 15
6. Growth and Nature of the Industry 19
Present technology 19
Production trends and growth factor 19
References 21
Appendices
A. Literature survey 25
B. Emissions data—sampling and computations 31
C. Source severity and affected population .48
Glossary 57
ix
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FIGURES
Number Pag<
1 Flow of crushed sandstone, quartz, and
quartzite operations 4
2 Distribution of sandstone, quartz, and
quartzite production 8
TABLES
1 Emission Factors and Mass Emission Levels From
Sandstone, Quartz, and Quartzite Sources 3
2 Crushed Sandstone, Quartz, and Quartzite Sold or
Used by Producers in the United States in 1972,
by State and Respective Population Density 7
3 Emission factors from Crushed Sandstone, Quartz,
and Quartzite Operations 11
4 Mass Emission Levels of Criteria Pollutants from
Crushed Sandstone, Quartz, and Quartzite
Operations 11
5 Pollutant Source Severities Per Unit Operation .... 14
6 Growth Rate of Crushed Sandstone, Quartz,
and Quartzite Production 20
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ABBREVIATIONS AND SYMBOLS
a...d, f — variable exponents and coefficients used in
numerous mathematical manipulations
A — cross-sectional area of falling granules
A — affected area-where x/F>0-l
3.
ANFO -- ammonium nitrate and fuel oil
A f — affected population where x/F>_0.1 for free silica
p particulates
b — width of the conveyor belt
BCD — background concentration of particulate
D_ — total dose of pollutant from a source
E — emission factor
E, co — emission factor for carbon monoxide from blasting
E. NQ — emission factor for nitrogen oxides from blasting
E. — blasting respirable particulate emission factor
E.. — blasting total particulate emission factor
E — conveying respirable particulate emission factor
E — crushing respirable particulate emission factor
\^±. JL.
E . — crushing total particulate emission factor
CxT w
E . — conveying total particulate emission factor
E, — drilling emission factor
E, — drilling respirable particular emission factor
Ej. — drilling total particulate emission factor
E, — loading emission factor
E, — loading respirable particulate emission factor
E,. — loading total particulate emission factor
E — stockpile respirable particulate emission factor
S JL
E — stockpile total particulate emission factor
S*Q
E. — transport respirable particulate emission factor
E.. — transport total particulate emission factor
XI
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LIST OF ABBREVIATIONS AND SYMBOLS (continued)
E — unloading emission factor
E — unloading respirable particulate emission factor
E . — unloading total particulate emission factor
E — washing and screening respirable particulate
emission factor
E . — washing and screening total particulate emission
wst factor
exp — natural log base e, 2.72
F — hazard factor
g — gravitational acceleration
GF — growth factor, 1982/1977 mass emissions
H — height of emission release
HC — hydrocarbons
Hf — height of fall
m — conveyor belt load
M — dispersion model designation
MI — tan 6
M2 — ratio of yi/xi
mph — miles per hour
P — production rate of crushed sandstone, quartz, and
guartzite
P.M. — particulate matter
Q — emission rate of a pollutant
Q — line source emissions rate
Q — total release of pollutants from a source
R — specific formation of airborne respirable dust
R/T — ratio of concentration of respirable to total
particulates
S — severity
S" --stability class
S Q . . .
S^ — high-volume sampler labels
SQQ — sandstone, quartz, and quartzite
TLV — threshold limit value
u — wind speed
xii
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ABBREVIATIONS AND SYMBOLS (continued)
U^ — linear speed of the conveyor belt
x, y, z — Cartesian coordinate points downwind of a
source
x — crosswind distance from a line source
c
x., y. — downwind distance Cartesian coordinate points
a — angle between downwind distance and line from
source to sampler
A — difference between downwind and background
concentration
0 — angle of mean wind direction
ir — constant pi, 3.14
p — material density of coal
\^r
a — standard deviation of horizontal plume dispersion
a — standard deviation of vertical plume dispersion
Z
a — instantaneous standard deviation of vertical
z dispersion
X — downwind concentration of a pollutant
— time-averaged maximum ground level concentration
— instantaneous dose concentration of a pollutant
xm
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CONVERSION FACTORS AND METRIC PREFIXES
To convert from
Centimeter (cm)
Centimeter2 (cm2)
Cent imeter 3 (cm3)
Degree Celsius (°C)
Kilogram (kg)
Kilogram (kg)
Kilometer2 (km2)
Meter (m)
Meter2 (m2)
Meter3 (m3)
Meter3 (m3)
Metric ton
Radian (rad)
CONVERSION FACTORS
to
Foot
Inch2
Inch3
Degree Fahrenheit
Pound-mass (Ib mass
avoirdupois)
Ton (short, 2,000
(Ib mass)
Mile2
Foot
Foot2
Foot3
Gallon (U.S. liquid)
Pound-mass
Degree (°)
Multiply by
3.281 x 10~2
1.550 x 10-1
6.102 x 10~2
> = 1.8 t° + 32
2.204
1.102 x ID"3
2.591
3.281
1.076 x 101
3.531 x 101
2.642 x 102
2.205 x 103
5.730 x 101
METRIC PREFIXES
Prefix Symbol Multiplication factor
Kilo
Centi
Milli
Micro
k
c
m
103
io-2
10~3
10~6
Example
1 kg
1 cm
1 mm
1 ym
1 x 103 grams
1 x 10~2 meter
1 x 10~3 meter
1 x 10"6 meter
Metric Practice Guide. ASTM Designation E 380-74, American
Society for Testing and Materials, Philadelphia, Pennsylvania,
November 1974. 34 pp.
xiv
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SECTION 1
INTRODUCTION
The conversion of naturally occurring sandstone, quartz, or
quartzite (SQQ) rocks into a crushed form involves mining from
open quarries and processing at finishing plants. Air pollution
emissions are created by the quarrying and processing activities,
An investigation of crushed sandstone, quartz, and quartzite
operations was conducted to provide a better understanding of
the distribution and characteristics of emissions from the data
available in the literature and limited sampling, and to ascer-
tain the need for developing control technology in the industry.
This document contains information on the following items:
• A method to estimate the emissions from crushed sandstone,
quartz, and quartzite processing.
• Composition of emissions.
• Hazard potential of emissions.
• Geographical distribution and source severity.
• Trends in the crushed sandstone, quartz, and quartzite
industry and their effects on emissions.
• Type of control technology used and proposed.
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SECTION 2
SUMMARY
The crushed sandstone, quartz, and quartzite industry converts
naturally occurring sandstone, quartz, arid quartzite rock depos-
its into a crushed form for use predominantly (83% of the output)
in the construction industry. There are 362 plants in the United
States which produced 24.3 x 106 metric tons3 of crushed sand-
stone, quartz, and quartzite in 1972, accounting for 2.9% of the
output of the aggregate industry (crushed limestone, granite,
stone, sand, gravel, sandstone, quartz, and quartzite). Contin-
gency forecasts of crushed sandstone, quartz, and quartzite
demands in the year 2000 have been reported to be 83.6 x 106
metric tons to 106.0 x 106 metric tons.
Atmospheric emissions of particulates occur from several unit
operations; drilling, blasting, loading and unloading trucks,
transport on unpaved roads, washing, crushing, screening, con-
veying, and stockpiling. Although an estimate of the emission
factor is available in the published literature as 5,650 grams
of suspended particulate per metric ton of processed material,
this number has not been validated by on-site sampling. Field
sampling of emissions was therefore conducted. The emission
factor for respirable particulates from crushed sandstone,
quartz, and quartzite processing is 3.6 g/metric ton, with wash-
ing, screening, crushing, and vehicular movement on unpaved roads
(between quarry and plant, and pit and plant) contributing about
80% of the value. The hazardous constituent of the emitted dust
is free silica (17 wt % average), prolonged exposure to which
may result in the development of a pulmonary fibrosis known as
silicosis. Particulate emission factors and the mass of total
and respirable particulates emitted from SQQ unit operations are
presented in Table 1. Emission factors for carbon monoxide,
nitrous oxides, and fibers are 1.68 g/metric ton, 2.85 g/metric
ton, and 1,360 fibers/metric ton, respectively.
A representative crushed sandstone, quartz, and quartzite plant
was defined by a production rate of 454 metric tons/hr; it emits
dust at the rate of 1.63 kg/hr respirable particulates (less than
al metric ton equals 106 grams; conversion factors and metric
system prefixes are presented in the prefatory material.
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TABLE 1. EMISSION FACTORS AND MASS EMISSION LEVELS
FROM SANDSTONE, QUARTZ, AND QUARTIZE SOURCES
Particulate emission factor,
g/metric ton
3Ma
Particulate mass emissions,
metric ton/yr
not add to 100% due to rounding.
Percent of total
Unit operation
Drilling
Blasting
Loading
Unloading
Washing and screening
Crushing
Conveying
Transport on unpaved roads
Stockpiles
TOTAL
Respirable
0.009
0.003
0.0006
0.05
0.84
1.34
0.11
0.74
0.4
3.6
Total
0.05
0.56
0.012
0.13
7.6
13.4
1.73
4.1
6.4
34.7
Respirable
0.2
0.07
0.01
1.2
20.4
32.6
2.7
6.8
9.7
84.88
Total
1.2
13.6
0.3
3.1
184.7
325.6
42.0
99.6
155.5
825.6
Respirable
0.24
0.08
0.01
1.41
24
38.41
3.2
21.21
11.43
iooa
Total
0.15
1.65
0.04
0.4
22.37
39.44
5.1
12.1
18.83
iooa
7 ym) and 15.7 kg/hr total particulates. The source severity
value is the ratio of the maximum ground level concentration
(calculated from the emission rate) at the representative plant
boundary to the pollutant hazard factor. The hazard factor, F,
is defined as the EPA primary air quality standard. When EPA
criteria do not exist, an adjusted threshold limit value (TLV®)
is used which allows for exposure time and general population
sensitivity. The maximum source severity due to respirable free
silica emissions from such a plant is 0.91. The population
exposed to an average ground level concentration (x") of free
silica from a representative plant for which x/F greater than
0.1 was estimated to be five persons.
Total particulates emitted from all SQQ sources account for
0.005% of the national mass emissions burden of particulates.
In Arkansas, 0.13% of the total particulates emitted are from
SQQ sources. Every other state has a lower SQQ emissions burden.
The mass of particulate emissions from SQQ sources is expected
to be 1.29 times greater in 1978 than it was in 1972 (based upon
a projected 4.3% annual growth rate for SQQ production).
Air pollution control is not widely applied to emissions from
crushed sandstone, quartz, and quartzite operations. Since the
quantity of dust emitted from these operations is dependent on
the dryness of material handled, any method used to add moisture
is helpful in controlling dust levels.
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SECTION 3
SOURCE DESCRIPTION
PROCESS DESCRIPTION
Emission Sources
The conversion of naturally occurring sandstone, quartz, or
quartzite deposits into a crushed form involves a series of
physical operations similar to those used in the crushed granite
and crushed stone industries as shown schematically in Figure 1.
The deposits are first loosened by drilling and blasting, then
washed, loaded, and transported to the processing plant by trucks
or belt conveyors. Processing includes such operations as crush-
ing, pulverizing, screening, and conveying. After processing,
the crushed material is loaded for transport to customers or to
stockpiles for storage.
WASHING,
SCREENING,
AND CRUSHING
CONVEYING
STORAGE
TRANSPORT
Figure 1. Flow of crushed sandstone, quartz,
and quartzite operations.
4
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Respirable particulate (less than 7 ym) emission sources in the
crushed sandstone, quartz, and quartzite industry can be divided
into two categories: 1) sources associated with actual process-
ing such as crushing, screening, and conveying operations; and
2) fugitive dust sources such as stockpiles and vehicle traffic
on unpaved roads. Quarrying operations such as drilling, blast-
ing, and transfer operations are also fugitive dust sources.
Source Composition
Sandstone is a detrital sedimentary rock formed by the cementa-
tion of individual grains of sand-size particles, 62 ym to 2 mm
in diameter. The grains in most sands are commonly composed of
mineral quartz, but many other minerals and rock fragments such
as feldspar, clay minerals, garnet, zircon, rutile, magnetite,
pyrite, chromite, etc., may also be present in small quantities
(1).
Quartzites are mostly formed by the metamorphism of sandstone;
however, some are also formed by metasomatic introduction of
quartz and other elements such as metals and sulfur (2).
Quartz is the most abundant and widespread of all minerals. It
has the chemical composition Si02 (silicon dioxide) and is the
principal constituent of sandstone, of quartzite, and of uncon-
solidated sand and gravel (2).
Sandstone, quartz, and quartzite are combined into one category
by the Bureau of Mines because of the similar end use of products.
This definition was adopted to facilitate data gathering in this
assessment.
FACTORS AFFECTING EMISSIONS
Calculation of the source severity and the state and national
emissions burdens, necessitates a knowledge of the emission rate
for every source in the country. Conducting emission measure-
ments on a source-by-source basis was impractical due to the
large number of individual sources and the diversity of source
types. A method was therefore developed to derive an emission
factor as grams of particulates emitted per metric ton of crushed
sandstone, quartz, or quartzite processed.
(1) McGraw-Hill Encyclopedia of Science and Technology, Volume 12.
McGraw-Hill Book Company, Inc., New York, New York, 1960.
pp. 23-25.
(2) McGraw-Hill Encyclopedia of Science and Technology, Volume 11.
McGraw-Hill Book Company, Inc., New York, New York, 1960.
pp. 180-183.
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The emission rate for each of the unit operations is estimated
as the product'of the emission factor and the crushed sandstone,
quartz, and quartzite production rate. This relationship can
be stated simply as shown in Equation 1.
Q = E x P (1)
where Q = emission rate of particulates, g/hr
E = emission factor in g/metric ton of crushed
sandstone, quartz, or quartzite processed
P = production rate of crushed sandstone, quartz,
or quartzite, metric tons/hr
The overall emissions from crushed sandstone, quartz, or quartz-
ite operations are due to drilling, blasting, loading, vehicular
movement on unpaved roads (between quarry and pit, and pit and
plant), crushing, conveying, screening, and stockpiling. Emis-
sions from all of these unit operations (except blasting) are
influenced by particle size distribution, rate of handling,
moisture content of the handled material, and type of equipment
used.
A detailed literature survey was conducted to obtain published
data on the extent to which various factors influence the over-
all emissions and on the relative contributions of the unit
operations to overall emissions. Although estimates of emission
factors for some unit operations are available in the published
literature, no studies were conducted or reported to validate
the estimated emission factors (Appendix A).
A limited sampling of emissions from a crushed quartzite plant
was therefore conducted. (See Appendix B for details and results
of the sampling.) The results of the sampling and the literature
study indicate that respirable free silica particulates are of
concern. Crushing, washing, screening, and transport on unpaved
roads account for over 80% of the respirable particulates emitted
from SQQ operations.
*
The factors influencing emissions from vehicular movement on un-
paved roads are vehicle speed, vehicle weight and cross-sectional
area, number of wheels, tire width, particle size distribution,
and moisture content of unpaved road surface material. Though
considerable literature is available on the magnitude of unpaved
road emissions, little has been done to correlate the emissions
with soil or vehicle characteristics.
GEOGRAPHICAL DISTRIBUTION
There were 362 crushed sandstone, quartz, and quartzite quarries
in the U.S. with a total output of 24.3 x 106 metric tons in
1972. Arkansas ranked first in output with 5.2 x 106 metric
tons in 1972, followed by California, Pennsylvania, Wisconsin,
-------
Texas, West Virginia, South Dakota, and Ohio. Together, these
8 states accounted for 73% of the total crushed sandstone, quartz,
and quartzite production in the United States (3). Table 2 and
Figure 2 present the crushed sandstone, quartz, and quartzite
output in 22 states in the United States.
TABLE 2. CRUSHED SANDSTONE, QUARTZ, AND QUARTZITE SOLD OR
USED BY PRODUCERS IN THE UNITED STATES IN 1972,
BY STATE AND RESPECTIVE POPULATION DENSITY
AmQunt Q.£ sandstone,
quartz, and quartzite Population
sold or used (4), density,
State 103 metric tons persons/km2
Alabama
Arizona
Arkansas
California
Colorado
Georgia
Missouri
Montana
New Mexico
New York
North Carolina
Ohio
Oregon
Pennsylvania
South Dakota
Texas
Utah
Vermont
Virginia
Washington
West Virginia
Wisconsin
Other states
TOTAL
52
505
5,180
4,828
195
75
201
352
100
648
58
836
168
3,263
854
960
137
46
668
811
920
1,038
2,476
24,344
27
7
15
50
7
31
27
2
3
145
39
102
9
103
3
17
5
19
46
20
29
31
Not determined
a
Includes Connecticut, Idaho, Kansas, Kentucky, Maryland,
Michigan, Minnesota, Nevada, New Hampshire, Oklahoma,
Tennessee, and Wyoming.
Data may not add to totals shown because of independent
rounding.
(3) Mineral Industry Surveys. U.S. Department of the Interior,
Washington, D.C., 1972. 12 pp.
(4) Drake, H. J. Stone. In: Minerals Yearbook, 1972, Volume I,
U.S. Department of the Interior, Washington, D.C., 1974
1172 pp.
-------
00
( 10 metric tons)
< 250
250 to 2,000
72,000
Figure 2. Distribution of sandstone, quartz, and quartzite production,
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SECTION 4
EMISSIONS
SELECTED POLLUTANTS
The major pollutants emitted from crushed sandstone, quartz,
and quartzite processing are particulates containing free silica.
The prolonged inhalation of these dusts may result in the devel-
opment of a disabling pulmonary fibrosis known as silicosis. The
action of silica on the lungs results in the production of a
diffuse, nodular fibrosis which is progressive and may continue
to increase for several years after exposure is terminated. The
first and most common symptoms of uncomplicated silicosis are
shortness of breath on exertion and dry cough. When the disease
advances, the shortness of breath becomes worse and the cough
more troublesome. Further progress of the disease results in
marked fatigue, loss of appetite, pleuritic pain, and total
incapacity to work. Extreme cases may eventually cause death
due to destruction of the lung tissues (5).
The American Conference of Governmental Industrial Hygienists
has suggested a TLV (in mg/m3) of 10/(% Quartz + 2) for respi-
rable dusts containing quartz or free silica. Dusts with less
than or equal to 1% silica are termed "inert," and a TLV of
10 mg/m3 is suggested for these (6). Each trace element inves-
tigated possesses a TLV documenting the hazardous nature of the
pollutant from a health or nuisance standpoint. Emissions of
carbon monoxide and nitrogen oxide from blasting are air criteria
pollutants which also possess suggested TLV's. Fibers are also
emitted from SQQ operations; they are associated with many forms
of fibrosis similar to silicosis.
(5) Sax, N. I. Dangerous Properties of Industrial Materials,
Third Edition. Reinhold Book Corporation, New York, New York,
1968. pp. 1088-1089.
(6) TLVs® Threshold Limit Values for Chemical Substances and
Physical Agents in the Workroom Environment with Intended
Changes for 1976. American Conference of Governmental
Industrial Hygienists, Cincinnati, Ohio, 1976. p. 32.
-------
CHARACTERISTICS
Mass Emissions
Emission factors for pollutants from crushed sandstone, quartz,
and quartzite plants were derived from literature and sampling
data (as detailed in Appendix B) and are presented in Table 3.
Mass emission quantities of these pollutants based on production
levels are presented in Table 4 along with the. percent of emis-
sions attributed to each operation.
The emission of total particulates from SQQ sources accounts for
0.005% of the national mass emission of total particulates and
0.13% of the mass emissions of total particulates in Arkansas.
Carbon monoxide and nitrogen oxide emissions account for less
than or equal to 0.009% of any state mass level and less than
0.001% of the national emission level of each pollutant.
Composition of Emissions
An analysis of the emissions from crushed sandstone, quartz, and
quartzite emissions (Appendix B) shows that free silica, consti-
tuting about 17% by weight, is the only hazardous component.
Remaining constituents are inert. An elemental analysis of the
particulate was also conducted (Appendix B, Table B-6), and the
average percentages were applied to the emission Factors for
respirable particulates to determine trace element emission
factors.
DEFINITION OF A REPRESENTATIVE SOURCE
Consultations with industry experts showed that crushed SQQ
plants have an average production rate of approximately 454 met-
ric tons/hr (personal communication with Fredrick A. Renninger,
National Crushed Stone Association, Washington, D.C.,
7 November 1975).
The mean emission factor was determined by sampling a crushed
quartzite plant with operating parameters similar to those of
the representative plant (Appendix B). Thus, the representative
source emits dust at a rate of 1.63 kg/hr respirable particulates
and 15.7 kg/hr total particulates.
The representative population density is taken as a production-
weighted population density and is equal to 38.8 persons/km2.
The percentage of SQQ sold or used by producers in each state
was utilized to weight the population density in each state
(Table 2). The resulting average population density of 38.8
persons/km2 is used as representative of the source. The repre-
sentative distance from the plant is defined using the major
contributing source within the plant as a reference point. The
distance of the plant boundaries from this reference point is
10
-------
TABLE 3. EMISSION FACTORS FROM CRUSHED SANDSTONE, QUARTZ, AND QUARTZITE OPERATIONS
(g/metric ton)
Emission factors
Unit operation
Prilling
Blasting
Loading
Unloading
Transport on unpaved roads
Washing and screening
Crushing
Conveying
Stockpiles
TOTAL
Respirable
particulates
0.009
0.003
0.0006
0.05
0.74
0.84
1.34
0.11
0.4
3.6
Total
particulates
0.05
0.56
0.012
0.13
4.1
7.6
13.4
1.73
G.4
34.7
Respirable
free silica
particulates
0.002
0.0005
0.0001
0.008
0.03
0.14
0.23
0.02
0.06
0.61
Carbon
monoxide
a
1.68
a
a
a
a
a
a
a
1.68
Nitrogen
oxides
a
2.85
a
a
a
a
a
a
a
2.85
Fibers
b
b
b
b
b
b
1,360
b
"b
1,360°
Not emitted. Not sampled and/or no literature available. Fibers/metric ton.
TABLE 4. MASS EMISSION LEVELS OF CRITERIA POLLUTANTS FROM
CRUSHED SANDSTONE, QUARTZ, AND QUARTZITE OPERATIONS
(metric tons/yr)
Mass emissions
Unit operation
Drilling
Blasting
Loading
Unloading
Washing and screening
Crushing
Conveying
Transport on unpaved roads
Stockpiles
TOTAL
Total
particulates
1.2
13.6
0.3
3.1
184.7
325.6
42.0
99.6
155.5
825.6
Percent
of
total
10.15
1.65
0.04
0.4
22.37
39.44
5.1
12.1
18.83
b
100
Carbon
monoxide
a
40.8
a
a
a
a
a
a
a
40.8
Percent
of
total
a
100
a
a
a
a
a
a
a
~
100
Nitrogen
oxide
a
69.2
a
a
a
a
a
a
a
™
69.2
Percent
of
total
a
100
a
a
a
a
a
a
a
~
100
Not emitted. May not add to 100% due to rounding.
-------
taken as the radius of a circle whose area is equal to the area
of the representative plant. By assuming crushed SQQ plants
have the same average area as crushed stone plants (0.53 km2),
the representative distance to the plant boundary is 410 m (7).
A representative SQQ plant growing at the same rate as the indus-
try is expected to have an annual growth rate of 4.3%. Similarly,
the mass emission level of particulates from the representative
plant in 1982 is expected to be 1.23 times greater than the 1977
level.
SOURCE SEVERITY AND AFFECTED POPULATION
The source severity, used to indicate the hazard potential of a
representative emission source, is the ratio of the time-averaged
maximum ground level concentration (xmax) to a hazard factor (F).
In order to calculate severity, S (which equals Xmax/F) (8)/ a
mathematical model describing the dispersion of pollutants in
the atmosphere is employed. For open sources, the model employs
the time-averaged concentration of a pollutant occurring at a
single point at ground level at the plant boundary. This concen-
tration may occur only once a year and be considered a worst case
concentration. The hazard factor is derived from ambient air
quality criteria or reduced threshold limit values.
Ground Level Concentration
The minimum distance from the major contributing emission source
to the representative crushed SQQ plant boundary has been deter-
mined to be 410 m. This is the minimum distance at which public
exposure to the pollutant could occur. The following formula in
conjunction with class C meteorological conditions (approximate
U.S. average) was used to calculate the maximum ground level,
instantaneous concentration, x (9) :
max
xmax ~ TTCF a u * '
(7) Blackwood, T. R., P. K. Chalekode, and R. A. Wachter. Source
Assessment: Crushed Stone. Contract 68-02-1874, U.S. Environ-
mental Protection Agency, Cincinnati, Ohio. July 1977. 91 pp.
(8) Eimutis, E. C., B. J. Holmes, and L. B. Mote. Source Assess-
ment: Severity of Stationary Air Pollution Sources - A Simu-
lation Approach. EPA-600/z-76-032e, U.S. Environmental Pro-
tection Agency, Research Triangle Park, North Carolina,
July 1976. 133 pp.
(9) Turner, D. B. Workbook of Atmospheric Dispersion Estimates.
Public Health Service Publication No. 999-AP-26, U.S. Depart-
ment of Health, Education, and Welfare, Cincinnati, Ohio,
May 1970. 84 pp.
12
-------
where Q = mass emission rate
av = 0.209 x°-903
az = 0.113 x°-911
u = 4.5 m/s (approximate U.S. average wind speed)
x = 410 m
IT = 3.14
The instantaneous ground level concentration of respirable free
silica particulates at 410 m (using the emission rate determined
for Equation C-7) is thus 3.4 yg/m3. This must be corrected to
the time-averaged maximum, Xmax' f°r ^4 ^r as described by
Nonhebel (10), so that the mean concentration becomes 1.9 yg/m3.
This means that the maximum ground level concentration at the
boundary of the representative plant during a 24-hr period is
1.9 yg/m3 above background levels (worst case).
Hazard Factor
Since no ambient air quality criteria exist for compounds such as
free silica, the hazard factor, F, is thus a reduced threshold
limit value and is defined as follows:
F = 2T x IM x TLV (3)
The derivation of F utilizes the TLV corrected from 8-hr to 24-hr
exposure, with a safety factor of 100 applied to the calculation.
The free silica hazard factor for the purposes of this report is
calculated as 1.77 yg/m3 (Appendix C), comparable to the hazard
factor for respirable emissions since the TLV is for respirable
emissions. For total particulates, F shall be defined as the
24-hr ambient air quality standard of 260 yg/m3.
Source Severity
For the representative crushed SQQ plant, the maximum severity
is determined from the ratio of the time-averaged maximum ground
level concentration of the emission species to the hazard factor
for the species (xmax/F)• Pollutant severity equations utilized
and source severities for respirable and free silica particu-
lates are calculated in Appendix C. The source severities per
unit operation are presented in Table 5.
Emissions of nitrogen oxides and carbon monoxide from blasting
possess severities of 0.09 and 0.0002, respectively. The sever-
ity for fibers from crushing operations is 2.2 x 10~7. Trace
element emissions possess a range of severities (Table C-3,
Appendix C) from 0.00001 to 0.04 (lead), based on sampling of
(10) Nonhebel, G. Recommendations on Heights for New Industrial
Chimneys. Journal of the Institute of Fuel, 33:479, 1960.
13
-------
TABLE 5. POLLUTANT SOURCE SEVERITIES PER UNIT OPERATION
Unit operation
Pollutant
Respirable
particulates
Free silica
particulates
Drilling
Blasting
Loading
Unloading
Washing and screening
Crushing
Conveying
Transport on unpaved roads
Stockpiles
0.00005
0.00003
0.00001
0.0005
0.008
0.013
0.001
0.007
0.0003
0.001
0.0007
0.0002
0.1
0.2
0.34
0.03
0.19
0.008
TOTAL
0.034
0.91
the crusher operation, which had the highest respirable particu-
late severity (Table 5). Based on these low severities, further
investigation of these pollutants is not warranted.
Affected Population
The affected population refers to the number of persons poten-
tially exposed to a time-averaged ground level concentration of
a pollutant, \, for which x/F is greater than 0.1. The affected
population was calculated for free silica since this is the only
pollutant species which has a source severity greater than 0.1.
The population potentially exposed to this level is five persons
(Appendix C).
14
-------
SECTION 5
CONTROL TECHNOLOGY
STATE OF THE ART
Air pollution control technology is not widely applied to emis-
sions from crushed sandstone, quartz, and quartzite operations.
The quantity of dust generated from the various operations is
dependent upon the dryness of the handled material; hence, any
method used to add moisture is helpful in controlling dust levels.
Natural phenomena such as rain or snow and in-process washing or
spraying operations inhibit dust emissions as the dust adhering
to water is less prone to be emitted.
FUTURE CONSIDERATIONS
The fugitive and point sources of dust in the processing of sand-
stone, quartz, and quartzite are drilling, blasting, loading,
unpaved road transport, crushing, screening, conveying, and
stockpiling.
Dust emissions from dry percussion drilling operations can be
controlled by adding water or water mixed with a surfactant into
the air used for flushing the drill cuttings from the hole.
Dilution ratios range from 800 to 3,000 parts of water to 1 part
surfactant. The proper amount of solution, about 0.026 m3/hr
for an 89-mm diameter hole, causes the drill cutting to be blown
from the hole as damp, dust-free pellets (11).
In conventional mining of coal, water-filled plastic bags with or
without solid stemming material (clay) are used for stemming dust
emissions from blast holes. This method reduces dust concentra-
tions by 20% to 80% and explosive consumption by about 10% (12).
Instead of liquids, pastes with a cellulose or bentonite base can
be used if they have "thixotropic" properties; i.e., they are
gelatinous in repose but become liquid when vibrated. A similar
control method may be applicable for reducing particulate emis-
sions from blasting in sandstone, quartz, and quartzite mining.
(11) Jones, H. R. Fine Dust and Particulates Removal. Noyes
Data Corporation, Park Ridge, New Jersey, 1972. 307 pp.
(12) Grossmueck, G. Dust Control in Open Pit Mining and
Quarrying. Air Engineering, 10(25):21, 1968.
15
-------
Release of carbon monoxide, nitrogen oxides, and other gases
such as aldehydes and hydrogen can be curtailed by having a dry
blast hole and by carrying out the detonation properly to prevent
incomplete combustion.
Loading of the blasted sandstone, quartz, and quartzite into
trucks by front-end loaders results in dust emissions. Wetting
of the broken stone with water or water mixed with a surfactant
will alleviate the dust emissions. Emissions due to wind erosion
during transport can be reduced by covering the load with a tar-
paulin or wetting its surface with water or water mixed with
chemicals.
Water application is also an effective method for controlling
emissions from unpaved roads; however, approximately 5% to 8%
moisture (by weight) must be applied to suppress the dust emis-
sions (13). Additives such as calcium chloride can be used to
reduce the surface tension of water so that the dust can be
wetted with less water. Calcium chloride can be applied at a
cost of approximately $0.15/m2 treated per year (14). The major
problem involved in its use is the corrosion of vehicle bodies
and leaching by rainwater or melting snow. More frequent appli-
cations may b'e necessary during summer months.
Another effective method of dust control is to mix stabilizing
chemicals into the road surface to a depth of approximately 20 mm
to 50 mm (15). One cement company uses a special emulsion agenta
and a treatment which involves spraying a solution of 4 parts of
water and 1 part of the emulsion agent at the rate of 0.0091 m3/m2
of the road surface. Certain pretreatment measures such as work-
ing the road surface into a stiff mud are necessary to prevent
the binder in this emulsion agent from sticking to the vehicles.
Periodic maintenance using a 1:7 emulsion agent/water solution
spray keeps the emulsion agent binder active. This dust control
program was found to give 3 years of service at a total cost of
$0.12/m2.
3Coheren, supplied by Golden Bears Division, Witco Chemicals Co,
(13) Dust Suppression. Rock Products, 75:137, May 1972.
(14) Vandegrift, A. E., L. J. Shannon, P. G. Gorman, E. W. Lawless,
E. E. Sallee, and M. Reichel. Particulate Pollutant
Systems Study, Volume III: Handbook of Emission Properties,
Contract CPA-22-69-104, U.S. Environmental Protection
Agency, Durham, North Carolina, May 1971. 607 pp.
(15) Significant Operating Benefits Reported from Cement Quarry
Dust Control Programs. Pit and Quarry, 63(7):116, 1971.
16
-------
In some counties in Iowa, mixing cutback asphalt into the toad
surface to a depth of 5 cm to 8 cm has been investigated (16).
This type of surface treatment reduces dust emissions, but it
requires periodic maintenance such as patching of the potholes.
Treating the road surface with oil once a month is another effi-
cient method of controlling unpaved road dust emissions. The
cost for such applications is estimated to be $0.10/m2 treated
per year (11). However, a study conducted in New Jersey shows
that 70% to 75% of the oil applied moves from the surface of the
road by dust transport and runoff, and thus the oil or its heavy
metal constituents such as^lead may cause ecological harm (17) .
Furthermore, surface oiling requires regular maintenance because
roads treated in this manner develop potholes.
Lignin sulfonates, byproducts from paper manufacture, are also
used to control dust emissions. A commercially available lignin
sulfonatea was tested on a farm access road in Arizona State
University (18). The method proved quite successful, giving 5
years of service and effective dust suppression at a cost of
$0.47/m2 for 5 years ($0.10/m2-yr).
Paving the road surface is the best method for controlling dusts,
but it is impractical due to the high cost involved and the tem-
porary nature of crushed sandstone, quartz, and quartzite plants.
The simplest and least expensive means of controlling dust from
crushing, screening, conveying, and stockpiling is through the
use of wetting agents and sprays at critical points. A crushed
rock production plant uses a dust suppression system*3 and a
chemical wetting agent. Approximately 0.004 m3 of the concen-
trated wetting agent is diluted 1,000 times by volume with water
using an automatic proportioner. The solution is sprayed at the
top and bottom of cone crushers at the rate of 0.0042 m3 of solu-
tion per metric ton of material being crushed. This system also
Orzan A, supplied by Crown Zellerbach Corporation.
Chem-Jet, supplied by Johnson-March Corporation.
(16) Hoover, J. M. Surface Improvement and Dust Palliation of
Unpaved Secondary Roads and Streets. ERI Project 856-S, Iowa
State Highway Commission, Des Moines, Iowa, July 1973. 97 pp.
(17) Freestone, F. J. Runoff of Oils from Rural Roads Treated to
Suppress Dust. EPA R2-72-054, U.S. Environmental Protection
Agency, Cincinnati, Ohio, October 1972. 29 pp.
(18) Bub, R. E. Air Pollution Alleviation by Suppression of
Road Dust. M.S.E. thesis, Arizona State University, Tempe,
Arizona, June 1968. 45 pp.
17
-------
helps in reducing dust emissions at transfer points, screening
operations, storage bins, and stockpiling operations (19).
Such a system has many cost-saving advantages. It requires no
ducts, hooding, or other enclosures for crushers, screens, or
conveyors. The equipment is in the open and allows the opera-
tors to see the entire material flow in open areas. The dust is
not collected and there is no solid waste disposal or water pol-
lution problem.
In a crushed stone plant (with processes similar to those of a
crushed sandstone, quartz, and quartzite plant), a baghouse is
used to control dust emissions from cone crushers, scalping
screens, and twin sizing screens, and at the shuttle and trans-
fer conveyors. The range of dust collected is 2,722 kg to
5,443 kg in a 10-hr day from a 182-metric ton/hr plant (20).
A baghouse does not provide for dust control in stockpile areas
unless these areas are totally enclosed.
The dust collected in the baghouse presents a solid waste prob-
lem. The alternative disposal methods are to put the dust into
settling basins or to develop sales opportunities. Depending on
the type of material and the local market conditions, such uses
may include manufactured sand, underslab fill, and asphalt
filler (21).
(19) Harger, H. L. Methods Used by Transit Mix Operators to Meet
Air Pollution Control District Requirements. National Sand
and Gravel Association and National Ready Mixed Concrete
Association, Washington, D.C., April 1971. 22 pp.
(20) Trauffer, W. E. Maine's New Dust-Free Crushed Stone Plant.
Pit and Quarry, 63(2):96, 1970.
(21) Ozol, M. A., S. R. Lockete, J. Gray, R. E. Jackson, and
A. Preis. Study to Determine the Feasibility of an Experi-
ment to Transfer Technology to the Crushed Stone Industry.
Contract NSF-C826, National Science Foundation, June 1974.
50 pp.
18
-------
SECTION 6
GROWTH AND NATURE OF THE INDUSTRY
PRESENT TECHNOLOGY
Present technological improvements include the use of larger and
more efficient crushing and screening plants. Primary crushing
is often done near the pit, usually using jaw or gyratory crush
ers. Secondary crushing is done by cone crushers or gyratories.
For screening, horizontal screens are generally used. Storage
of finished crushed sandstone, quartz, and quartzite is done in
open areas.
In refractory plants, rotary washers or water tables are used to
remove impurities such as clay, and ball mills or rod mills are
used for grinding.
PRODUCTION TRENDS AND GROWTH FACTOR
Production of crushed sandstone, quartz, and quartzite is tied
closely to activity in the product consuming industries. Since
the construction industry consumes more than 83% of the output,
the production of crushed sandstone, quartz, and quartzite is
associated chiefly with the needs of this industry (3). The
annual growth rate is assumed is equivalent to that of the sand
and gravel industry, 3.9% to 4.7% (22), with an average of 4.3%
per year. The forecast for crushed sandstone, quartz, and quartz-
ite demand until the year 2000 is presented in Table 6.
Transportation costs constitute a major part of the delivered
cost of crushed sandstone, quartz, and quartzite. In many cases,
these costs may exceed the sales value of the material at the
processing plant. Hence, such plants are located near the point
of use. However, local zoning and environmental regulations and
depletion of urban deposits may necessitate the location of
future plants away from the point of use. This should increase
(22) Ochsner, J. C., P. K. Chalekode, and T. R. Blackwood.
Source Assessment: Transport of Sand and Gravel. Contract
68-02-1874, U.S. Environmental Protection Agency, Cincinnati,
Ohio. (Final document submitted to the EPA by Monsanto
Research Corporation, October 1977.) 63 pp.
19
-------
TABLE 6.
GROWTH RATE OF CRUSHED SANDSTONE,
QUARTZ, AND QUARTZITE PRODUCTION
Year,
Production,
103 metric tons
1972
1977
1982
1990
1995
2000
24,344
30,049
37,090
51,941
64,110
79,131
the use of rail and barge systems in order to hold down trans-
portation costs. Truck haulage will still remain important,
especially for local delivery of crushed product, even if rail
and water transportation are used for long hauls to central dis-
tribution points. This finally may result in an increase in the
delivered price of crushed sandstone, quartz, and quartzite.
A growth factor for SQQ source emissions is computed from the
ratios of mass emission levels in 5 years to the present level.
Based on the data presented in Table 6, the growth factor for
total particulate emissions from the period 1972 to 1978 is 1.23.
20
-------
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U.S. Environmental Protection Agency, Cincinnati, Ohio.
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A Simulation Approach. EPA-600/z-76-032e, U.S. Environ-
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Carolina, July 1976. 133 pp.
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Public Health Service Publication No. 999-AP-26, U.S.
Department of Health, Education, and Welfare, Cincinnati,
Ohio, May 1970. 84 pp.
10. Nonhebel, G. Recommendations on Heights for New Industrial
Chimneys. Journal of the Institute of Fuel, 33:479, 1960.
21
-------
11. Jones, H. R. Fine Dust and Particulates Removal. Noyes
Data Corporation, Park Ridge, New Jersey, 1972. 307 pp.
12. Grossmueck, G. Dust Control in Open Pit Mining and Quarry-
ing. Air Engineering, 10 (25):21, 1968.
13. Dust Suppression. Rock Products, 75:137, May 1972.
14. Vandegrift, A. E., L. J. Shannon, P. G. Gorman, E. W.
Lawless, E. E. Sallee, and M. Reichel. Particulate Pollut-
tant Systems Study, Volume III: Handbook of Emission
Properties. Contract CPA-22-69-104, U.S. Environmental
Protection Agency, Durham, North Carolina, May 1971.
607 pp.
15. Significant Operating Benefits Reported from Cement Quarry
Dust Control Programs. Pit and Quarry, 63(7):116, 1971.
16. Hoover, J. M. Surface Improvement and Dust Palliation of
Unpaved Secondary Roads and Streets. ERI Project 856-S,
Iowa State Highway Commission, Des Moines, Iowa, July 1973.
97 pp.
17. Freestone, F. J. Runoff of Oils from Rural Roads Treated
to Suppress Dust. EPA R2-72-054, U.S. Environmental Pro-
tection Agency, Cincinnati, Ohio, October 1972. 29 pp.
18. Bub, R. E. Air Pollution Alleviation by Suppression of
Road Dust. M.S.E. thesis, Arizona State University, Tempe,
Arizona, June 1968. 45 pp.
19. Harger, H. L. Methods Used by Transit Mix Operators to
Meet Air Pollution Control District Requirements. National
Sand and Gravel Association and National Ready Mixed Con-
crete Association, Washington, D.C., April 1971. 22 pp.
20. Trauffer, W. E. Maine's New Dust-Free Crushed Stone Plant.
Pit and Quarry, 63(2):96, 1970.
21. Ozol, M. A., S. R. Lockete, J. Gray, R. E. Jackson, and
A. Preis. Study to Determine the Feasibility of an Experi-
ment to Transfer Technology to the Crushed Stone Industry.
Contract NSF-C826, National Science Foundation, June 1974.
50 pp.
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Source Assessment: Transport of Sand and Gravel. Con-
tract 68-02-1874, U.S. Environmental Protection Agency,
Cincinnati, Ohio. (Final document submitted to the EPA by
Monsanto Research Corporation, October 1977.) 63 pp.
22
-------
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June 1974. 172 pp.
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31. Criteria for a Recommended Standard: Occupational Exposure
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32. Criteria for a Recommended Standard: Occupational Exposure
to Asbestos. HSM 72-10267, U.S. Department of Health,
Education, and Welfare, Rockville, Maryland, 1972. 89 pp.
plus appendices.
23
-------
33. Air Quality Data - 1972 Annual Statistics. EPA-450/2-74-001,
U.S. Environmental Protection Agency, Research Triangle
Park, North Carolina, March 1974. 137 pp.
34. 1972 National Emissions Report. EPA-450/2-74-012, U.S.
Environmental Protection Agency, Research Triangle Park,
North Carolina, June 1974. 422 pp.
35. Blackwood, T. R., and R. A. Wachter. Source Assessment:
Coal Storage Piles. Contract 68-02-1874, U.S. Environ-
mental Protection Agency, Cincinnati, Ohio, July 1977.
96 pp.
24
-------
APPENDIX A
LITERATURE SURVEY
A study was made to predict and analyze those parameters affect-
ing dust emissions from the seven handling operations in crushed
sandstone, quartz, and quartzite processing:
drilling and blasting operations
transport operations
conveying operations
unloading operations
open storage
loading operations
crushing/grinding/sizing operations
Parameters analyzed fell into two major classifications: 1) those
dependent on the material and 2) those dependent on the operation,
As could be expected, parameters dependent on the operation are
as varied as the operations themselves. Material-dependent para-
meters, however, are generally the same for all operations.
These are: 1) moisture content, 2) density, and 3) "dustiness
index," which will be defined as the mass of respirable dust
adhering to 2.2 kg of material. The "dustiness index" is used
to determine differences in emissions from different materials
undergoing the same operation.
Density, on the other hand, delineates differences in particle
size distribution between different samples of the same material.
DRILLING AND BLASTING OPERATIONS
The following factors influence the dust emissions from drilling
operations:
1) number of bits
2) sharpness of the bits
3) speed of the bits
4) depth of bit penetration
5) experience of the machine operator
The literature search did not yield any quantitative data nor
indicate a relationship between the emission factor and the
aforementioned factors. A qualitative relationship might pos-
sibly resemble:
25
-------
E a (A-l)
Ed a (2) (4) (5) (A L)
where the numbers in parentheses represent functions of the
respective variables shown above.
Of all the unit operations, blasting has been studied least from
the point of view of dust emissions. The literature search
yielded a potential list of factors influencing emissions:
1) frequency of blasting, 2) bulk moisture content of the rock,
3) particle size distribution, 4) type and amount of explosive,
and 5) hole size.
Some studies have been conducted on the magnitude of gaseous
emissions of nitrogen oxides (NOX) and carbon monoxide (CO) from
blasting. Stoichiometric ratios of ammonium nitrate-fuel oil
(ANFO) mixtures (5.5% fuel oil) should result in no emissions of
NOx and CO. Theoretically, more fuel oil results in no NOX and
more CO than carbon dioxide (CO2), and less fuel oil results in
no CO and more NOX than nitrogen (N2). Experimental investiga-
tions by the U.S. Bureau of Mines (23) show that 4% fuel oil
results in 1.3 m3 (at standard conditions) of NOX per kg of ANFO
and 1.3 m3 of CO per kg of ANFO, while 6% fuel oil results in
0.32 m3 of NOX per kg of ANFO and 1.8 m3 of CO per kg of ANFO.
The maximum emission factor figures have been used for the
severity calculations.
TRANSPORT OPERATIONS
Transport operations are discussed in detail in another assess-
ment document (22).
CONVEYING OPERATIONS
Dust emissions from conveying operations come from windblown dust
during open conveying and conveyor discharge.
Emissions from conveyor discharge and parameters affecting these
emissions were evaluated by Cheng (24) . The material tested was
freshly mined coal, cut during a dry operation and placed in
plastic bags to maintain its natural surface moisture of about
0.8% as measured by a Soiltest Speedy Moisture Tester. Cheng
found the following 'relationship:
(23) Chaiken, R. F. , E. B. Cook, and T. C. Ruhe. Toxic Fumes from
Explosives. Ammonium Nitrate-Fuel Oil Mixtures. Bureau of
Mines RI-7867 (PB 233 496), U.S. Department of the Interior,
Washington, D.C., May 1974. 29 pp.
(24) Cheng, L. Formation of Airborne-Respirable Dust at Belt
Conveyor Transfer Points. American Industrial Hygiene
Association Journal, 34(12):540-546, 1973.
26
-------
R = 8'5° X
where R = specific formation of airborne respirable dust, g
_A = cross-sectional area of the falling granules, cm2
pc = material density of the coal, g/cm*
g = gravitational acceleration =980 cm/s2
Hf = height of fall, cm
m = belt load, g/cm2
b = width of the conveyor belt, cm
Ufc = linear speed of the conveyor belt, cm/s
Cheng concluded the following:
• About 10% of the adhering respirable dust becomes airborne
by the impact of dropping.
• Reduction of the height of material fall reduces the forma-
tion of airborne respirable dust.
• For heavy belt loads (coal bed thickness much greater than
mean lump size), an increase in the thickness of the coal
bed reduces the specific formation of airborne respirable
dust.
UNLOADING OPERATIONS
Emissions from unloading operations result from dropping mate-
rials from conveying machinery onto storage piles. An EPA study
(25) found an emission factor, E, for unloading operations, based
on milligrams of suspended dust particles less than 30 ym in
diameter per kilogram of aggregate unloaded, to be represented
by the relationship:
_ 20 mg of particulate (A-3)
u kg of aggregate
This emission factor was based on high-volume sampling at a sand
and gravel plant in the Cincinnati area. Eu was believed to be
dependent on the surface moisture of the material, estimated by
the Precipitation-Evaporation (P-E) Index.
For an analysis of other factors affecting emissions from unload-
ing operations, see Section 3 "Conveying Operations." Although
(25) Cowherd, C. Development of Emission Factor for Fugitive
Dust Sources. EPA-450/3-74-037, U.S. Environmental Protec-
tion Agency, Research Triangle Park, North Carolina,
June 1974. 172 pp.
27
-------
the relationships derived for. emissions from conveyor discharge
are based on coal conveyance, only a correction factor for the
relative dustiness of the material handled need be applied to make
the equation applicable to all conveying and unloading operations.
OPEN STORAGE
Emissions due to open storage have been discussed in detail in
previous documents (22, 25, 26).
LOADING OPERATIONS
Emissions from loading operations occur in the transfer of mate-
rial from storage to transporting vehicles. For aggregates, this
transfer is accomplished by power shovels or front-end loaders
scooping the material from open storage piles and dumping it into
transporting vehicles, usually trucks. Dust arises from the
scooping and dropping processes.
Emissions from dropping are determined by many of the same para-
meters that determine dust formation from conveyor discharge,
although there are definite dissimilarities in mode of discharge
between conveyor belts and power shovels. Dust emissions should
be determined by:
1) Height of material fall
2) Quantity of material dumped
3) Density of material
4) Rate at which material is dumped
5) Moisture content of material
6) "Dustiness index" of material
An equation determining the amount of respirable dust (R) formed
by power shovel discharge, based on an equation for conveyor dis-
charge, should be of the form:
w „ (DO) (6) , ..
K a (2) (4) (5)
where a number in parentheses represents a function of its
respective parameter, as listed above.
Dust emissions from scooping operations are more difficult to
define, since no information even remotely relevant was available.
However, the following factors are believed to play a large part
in determining emissions from this source:
(26) Blackwood, T. R., T. F. Boyle, T. L. Peltier, E. C. Eimutis,
and D. L. Zanders. Fugitive Dust from Mining Operations.
Contract 68-02-1320, Task 6, U.S. Environmental Protection
Agency, Research Triangle Park, North Carolina, May 1975.
p. 34.
28
-------
7) Density of material
8) Moisture content of material
9) "Dustiness index" of material
10) Degree of storage pile disturbance rendered by the
scooping machinery
Although there is no basis for determining a relationship
between these variables and respirable dust formation (4) , a
qualitative relationship might possibly resemble
R „ (A-S)
where the number in parentheses represents a function of the
respective variable shown above.
Although not applicable to the determination of R, an EPA study
(25) found an emission factor, which can be expressed as milli-
grams of dust less than 30 ym in diameter emitted per kilogram
of material loaded, for loading crushed limestone at an asphalt
plant in Kansas City to be:
- 25 mg of dust I-
*! kg of material loaded
E, was believed to vary with the P-E Index of the area considered.
CRUSHING/GRINDING/SCREENING OPERATIONS
Emissions from crushing, grinding, and screening (sizing) opera-
tions result from respirable dust formation during size reduction
and crusher or screen discharge.
The factors affecting discharge emissions are the same as those
for conveyor and power shovel discharge (see "Conveying
Operations," and "Loading Operations" sections).
Dust emissions from size reduction are judged to be influenced by:
1) "Dustiness index" of material
2) Moisture content of material
3) Degree of particle-size reduction
4) Rate of material flow through size reducer
A qualitative expression for respirable dust formation (R) is
believed to be:
p „ (1) O) (A_7)
R a 72J74T ( }
where each number in parentheses is some function of the respec-
tive parameter listed above.
29
-------
If atmospheric dispersion of the respirable dust formed is to
occur, an induced air flow must be present. For most crushers,
which operate at a relatively low speed, air flow is induced
only during discharge. (See "Conveying Operations" for a quan-
titative evaluation of air flow induced by discharge.)
High-speed pulverizers create air flow during both size reduction
and discharge. Air flow induced by high-speed size reduction has
been found to be inversely proportional to the rate of material
flow through the size reducer (27).
(27) Andresen, W. V. Industrial Hygiene Design in Raw Materials
Handling Systems. American Industrial Hygiene Association
Journal, 23 (6):509-513, 1962.
30
-------
APPENDIX B
EMISSIONS DATA—SAMPLING AND COMPUTATIONS
SAMPLING SITE DESCRIPTION
The purpose of the sampling conducted was to obtain data, on
emissions from specific unit operations, presently lacking in
the literature. Sampling was therefore limited in scope to pro-
vide an insight into the magnitude of emissions generation by
various unit operations within the crushed sandstone, quartz,
and quartzite (SQQ) industry.
A crushed quartzite plant was chosen for sampling since quartzite
represents the average in the metamorphic scale between sandstone
and quartz formation. In this manner, a more representative free
silica content, the initial pollutant of primary concern, would
be encountered. The site sampled contained three separate areas
of operation; quarry, pit, and processing plant.
Quarry
At the quarry drilling is conducted to implant charges of ANFO to
loosen the quartzite from the rock strate. An average of 8 to 9
holes are drilled once a month for 8 hours. A rough average of
7,716 metric tons/month of quartzite is then blasted. The blasted
material is loaded by shovel onto 5.4-metric-ton trucks. The
trucks then transport this material over unpaved roads to a pit
area.
Pit
In the pit area, trucks dump and unload quartzite into a dump
station. The aggregate is then conveyed to a wash tower for
removal of clay and other foreign matter. In addition, the
material is classified into three sizes: 1) 19 mm to 38 mm,
2) 6 mm to 19 mm, and 3) less than 6 mm. The classified and
washed material is loaded through one of three hoppers to 8.2-
or 22.7-metric-ton trucks for shipment to the processing plant
or placement in stockpiles. As it is required by the processing
plant, quartzite is loaded on trucks from storage at the pit by
front-end loaders. The trucks transfer the material over unpaved
roads to the processing plant. Only those unpaved roads located
within the plant boundary are considered from an emissions
standpoint.
31
-------
Processing Plant
The plant utilizes quartzite in the production of bricks.
Quartzite transferred to the plant is either placed in storage or
dumped into a receiving hopper. Material in storage is placed in
the hopper by a front-end loader. The aggregate is then conveyed
to grinding (crushing) mills. These units exhaust through bag-
type filters to the atmosphere. However, emissions from SQQ
plants are studied from an uncontrolled perspective. The crush-
ing units operate an average of 8 hr/day, 3 days/wk throughout
the year. They handle 363 metric tons/month. Further operations
at the processing plant are concerned with the manufacture of
bricks and are not included within this source category.
The operation times and rates determined for the plant sampled
are used in determining the emission factors for this plant.
However, these data are also applicable to the representative
plant, since the ratio of the operating times and rates is
assumed constant. For example, if the amount of material blasted
at the representative plant is greater, then the emission rate
will increase proportionally. The operating times and rates for
the source sampled are presented in Table B-l.
TABLE B-l.
CRUSHED SANDSTONE, QUARTZ, AND QUARTZITE
OPERATING CHARACTERISTICS AT SAMPLED PLANT
Emission source
Operating time
Operating rate
Drilling
Blasting
Truck loading
Truck unloading
Transport
Washing and screening
Conveying
Crushing
Stockpiles
8 hr
drilling
0.02 hr
truck
0.01 hr
truck
0.019 hr
truck
b
Continuous
7,716 metric tons
drilling
7,716 metric tons
blast
truck
5.4 metric tons
truck
5.4 metric tons
truck
22.4 metric tons
57 metric tons
hr
67 metric tons
hr
10 metric tons
hr
Continuous
Finite release. Included in operating rate.
32
-------
SAMPLING PROCEDURES
Samplers
General Metal Works9 high-volume samplers were positioned around
an entire area, as shown in Figure B-l.
WIND AZIMUTH
METEOROLOGICAL STATION
Figure B-l. Sampling arrangement.
For this arrangement, the origin was defined at the source and
all all remaining points in the usual Cartesian coordinate
system. The angle of mean wind direction was 0. The downwind
distance of any point y^ perpendicular to the wind direction
centerline was computed in the following manner:
= tan e
(B-l)
and for point S. with coordinates
xi
(B-2)
General Metals Works, Inc., 8368 Bridgetown Road, Cleveland,
Ohio 45002.
33
-------
The angle a was found from
= arctan
mi • m2
The lateral distance Y. is:
= (sin a) /x2 + y2 (B-4)
y
and the downwind distance X. is:
X. = (cos a) /x.2 + y.2 (B-5)
i 11
These values are used in appropriate dispersion models. The sam-
pling time for high-volume samplers was about 4 hours. Five dif-
ferent samplers were used to monitor emissions in the entire area
at positions S0, Si, S2, S3, and S^.
a
A GCA respirable dust monitor was used to obtain downwind concen-
trations of respirable and total particulates from unit operations
(28). The sampling time for the GCA instrument was about 4 min-
utes and hence only one unit was necessary to monitor at all the
positions (not simultaneously).
The high-volume samplers collect particles less than 100 ym in
size, while the GCA unit collects less than 10-ym particles with
a cyclone separator and less than 50-ym particles without a
cyclone separator.
Models
Open source sampling uses diffusion models in reverse. Normal
use is to predict concentrations surrounding a point source of
known strength. Several concentration readings are taken to
calculate the source strength of an open source.
Models applicable to the sampling arrangement and source charac-
teristics are chosen and utilized for each source of emissions.
Three models are used in this study. The first represents emis-
sions from front-end loading and runs 1 and 2 performed on the
entire plant. This is the point source model (9) where:
GCA Corporation, GCA/Technology Division, Bedford, Massachusetts,
(28) Lilienfeld, P., and J. Dulchinos. Portable Instantaneous
Mass Monitor for Coal Mine Dust. American Industrial
Hygiene Association Journal, 33(3):136, 1972.
34
-------
X (x, y, z; H) = Q
(B-6)
The notation used to depict the concentration is x (x, y, z; H).
H, the height of the plume centerline from the ground level when
it becomes essentially level, is the sum of the physical stack
height, h, and the plume rise, AH. The following assumptions
are made: the plume spread has a Gaussian distribution in both
the horizontal and vertical planes, with standard deviations of
plume concentration distribution in the horizontal and vertical
of ay and az, respectively; the mean wind speed affecting the
plume is u; the uniform emission rate of pollutants is Q; and
total reflection of the plume takes place at the earth's surface;
i.e., there is no deposition or reaction at the surface. Any
consistent set of units may be used. The most common is x in
g/m3, Q in g/s, u in m/s, and oy, 0Z, H, x, y, and z in meters.
The concentration x is a mean over the same time interval as the
time interval for which the cr' s and u are representative. The
values of both ay and az are evaluated in terms of the downwind
distance, x, and stability class. Stability classes are deter-
mined conveniently by graphical methods, Figure B-2. Continuous
functions are then used to calculate values for Oy and az, from
Tables B-2 and B-3, given the downwind distance, x (29). In
open source sampling, the sampler is maintained in the center of
the plume at a constant distance; the plume has no effective
height (H equals 0); and the concentrations are calculated at
ground level. Equation B-6 thus reduces to (9):
(B~7)
y z
The second model is used to describe emissions from transport on
unpaved roads. In this equation, instantaneous puff concentra-
tions are described by (30) :
1
= ®
(29) Eimutis, E. C., and M. G. Konicek. Derivations of Continuous
Functions of the Lateral and Vertical Atmospheric Dispersion
Coefficients. Atmospheric Environment, 6 (11):859-863, 1972.
(30) Gifford, F. A., Jr. An Outline of Theories of Diffusion in
the Lower Layers of the Atmosphere. In: Meteorology and
Atomic Energy 1968, Chapter 3, D. A. Slade, ed. Publication
No. TID-24190, U.S. Atomic Energy Commission Technical Infor-
mation Center, Oak Ridge, Tennessee, July 1968. pp. 65-116.
35
-------
U)
START
ATMOSPHERIC
CLASS ISD
CD
RADIATION INDEX = - 2
RADIATION INDEX =
-1
.1
TIME OF DAY
INSOLATION
CLASS
NOONTIME
LATE AM, EARLY PM
MID AM, MIDPM"
EARLY AM, LATE PM
4
2
I
WIND .
SPEED
CALM
(0 - 2 mph)
LIGHT
fit- 5 mph)
MODERATE
B - 10 mph)
STRONG
I > 10 mph)
, 1«J RADIATK
4
A
A
B
C
J
A
B
B
C
2
B
C
C
D
I
C
D
D
D
IJNOEX
T
D
D
D
D
-1
JF
E
D
D
-I
T
r
i
D
STABILITY CATEGORIES
Figure B-2. Flow chart of atmospheric stability class determination.
-------
TABLE B-2.
VALUES OF a FOR THE COMPUTATION OF a a (30)
Stability class
A
B
C
D
E
F
0.3658
0.2751
0.2089
0.1471
0.1046
0.0722
For the equation
where x = downwind distance
b = 0.9031
TABLE B-3.
VALUES OF THE CONSTANTS USED TO
ESTIMATE VERTICAL DISPERSION3 (30)
Usable range,
m
Stability
class
Coefficient
>1,000
100 to 1,000
A
B
C
D
E
F
A
B
C
D
E
F
0.00024
0.055
0.113
1.26
6.73
18.05
C2
0.0015
0.028
0.113
0.222
0.211
0.086
2.
1.
0.
0.
,094
,098
,911
,516
0.305
0.18
d2
1.941
1.149
0.911
0.725
0.678
0.74
-9.6
2.0
0.0
-13
-34
-48.6
9.27
3.3
0.0
-1.7
-1.3
-0.35
<100
A
B
C
D
E
F
0.192
0.156
0.116
0.079
0.063
0.053
0.936
0.922
0.905
0.881
0.871
0.814
0
0
0
0
0
0
For the equation
0_ =
cxd + f
37
-------
where ty = dose, g-s/m3
QD = line source emissions per length of line, g/m
a = instantaneous vertical dispersion parameter, m
u = mean wind speed, m/s
For neutral stability:
azl = 0.15 xc°-7 (B-9)
where xn = crosswind distance from the line source, m
\—
Equation B-8 is a line source diffusion model and is used to find
the mass emissions per length of road. The value of the dose, ty ,
is determined by multiplying the concentration by the actual sam-
pling time.
The third model is used in computing total dose from a finite
release in blasting. This is calculated from Equation B-10 (9) :
Q
DT = FlTu-6 2 (B-10)
y z
The parameters of Equation B-10 use the same units as Equation
B-6, except Q^ is the total release in grams from the source,
and DT is the total dose, g-s/m3. Again, the dose is the product
of the concentration and sampling time. Equation B-10 is there-
fore termed a dose model.
Data Collection
Each variable for each of these models was determined in the field
at meteorological stations. High-volume sampling used a station-
ary meteorology station. Wind speeds were averaged every minute
with a mean recorded for each 15-minute interval. The mean wind
speed was calculated from the average of the 15-minute recordings
over the entire run. The samplers were therefore maintained with-
in the plume during sampling. The wind direction variation was
less than ±0.79 rad from the center line during the samplings.
The concentration at sampler S0 was subtracted from the concentra-
tions at Si, S2, 83, and S^ to yield concentrations due to the
source emissions. -Mass emission rate was then calculated as an
average of the calculations done for N sampler readings using the
appropriate dispersion equation.
The respirable dust monitor was mounted on the portable meteoro-
logical station shown in Figure B-3. For each monitor concentra-
tion reading, displayed by direct digital readout, the mean wind
38
-------
\
ANEMOMETER'
/P^Th— ANEMOMETER
' r uniiQiMr.
CLIPBOARD
WIND METER.
HOUSING
WEATHER POLE
^| CYCLONE SEPARATOR
RESPIRABLEDUST
MONITOR
SAMPLING PLATFORM
STOPWATCH
TRIPOD STAND
Figure B-3. Sampling apparatus.
speed was determined by averaging 15-s readings (a stopwatch was
used) of the wind meter. This meter is connected to the anemome-
ter which sits atop a 3.05-m pole. Distance x was approximated
by manually pacing over the rough terrain.
All these data were recorded for each sampling run on the form
shown in Figure B-4 while in the field. The time of day and
atmospheric stability (determined following Figure B-2) were
recorded periodically on the bottom of the form.
The terms used on the field data form (Figure B-4) are explained
in Table B-4.
Any factors that might have affected concentration or emission
rate were mentioned in the column labeled "Comments." When this
form was completed, the data were programmed into a computer, and
the emission rate, Qf was calculated in accordance with the model
specified in the column labeled "M."
39
-------
MODEL:
POINT -1
LINE =2
SOURCE TYPE
DATE
BY_
UNIT OPERATION
WIND
SPEED
MPH
DIS1
X
FANG
Y
E, FT
TIME
MIN
READ.
mg/m3
CONG
TIME OF DAY
A T • A f*T A n 1 I 1 T\/ _ , — n —
ATM.STABILITY — •
R/T
BCD
riti
Q,
g
s1
M
COMMENTS
TOTAL SAMPLING TIME MULTIPLY READING BY
4 MINUTES 1
8 MINUTES 0.46
16 MINUTES 0.23
20 MINUTES 0.184
30 MINUTES 0.122
37 MINUTES 0.1
Figure B-4. Field data form.
-------
TABLE B-4. EXPLANATION OF FIELD DATA FORM TERMS
Term Meaning
Read., mg/m3 Concentration reading
Cone., yg/m3 Converted concentration for sampling times >4 minutes (lower
right-hand corner)
R/T R = respirable reading, T = total mass reading
BGD, yg/m3 Background concentration
A, ug/m3 The difference between the converted concentration and the
background
Q, g or g/s Calculated emission rate
S1 Stability for the time of day the unit operation was sampled
M The model used referenced as 1, 2, or 3 (point, line, or dose,
respectively)
EMISSION LEVELS
Particulates
The parameters of Equations B-6, B-8, and B-10 were measured in
the field in order to determine the emission rates (Q) per unit
operation from the dispersion models. These data are recorded
on the form in Figure B-4 and printed out via computer in Table
B-5. The value of Q is automatically calculated from the dis-
persion model (M) specified in the input (Figure B-4). Measure-
ments were performed on only those sources lacking published
data. By sampling the site described in this appendix and
referring to other studies, the following emission factors were
determined.
Drilling—
Particulate emissions from drilling holes for loosening quartzite
from the strata were assumed equivalent to those levels reported
in a crushed stone operation (7). The levels for respirable and
total particulates from drilling (E^r and Edt) are 0.005 and
0.05 g/metric ton, respectively. Respirable particulates account
for 10% of the total particulates emitted in wet drilling.
Blasting—
The blasting operation was sampled at the quartzite site. The
dose model (Equation B-10) yielded emission quantities of
4,366 g and 44.2 g of total and respirable particulates,
respectively.
This finite release occurred during the blasting of an approxi-
mated average of 7,716 metric tons (Table B-l). Therefore the
41
-------
TABLE B-5. SAMPLING DATA AND RESULTS
Preliminary sampling data and results
a
Unit operation
Run 1 — Si»
Run 2 — Si
Run 2
Front end loading.
Front end loading
Washing plant — over
Unpaved road
Unpaved road
Unpaved road
Unpaved road
Blasting"
Blasting
u
4.6
5.0
5.0
1.0
5.0
12.0
5.0
8.0
5.0
5.0
3.0
3.0
x
226
150
150
50
50
250
20
25
30
35
300
300
y
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0.
0.0
0.0
40.0
40.0
z
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
Time
210
145
4
4
8
7
4
8
4
8
8
16
x
171.6
148.9
10.0
100.0
4.6
271.0
110.0
73.6
160.0
41.4
101.2
5,000.0
Q
1.077E'1
4.806E"2
7.472E-1*
8.692E~lf
4.842E"5
1.209E"1
1.197E"1*
1.559E~lf
5.380E"1*
i.eosE"1*
4.418E1
4.366E3
Units
(g/s)
(g/s)
(g/s)
(g/s)
(g/s)
(g/s)
(g/m-s)
(g/m-s)
(g/m-s)
(g/m-s)
g
g
s1
B
B
D
B
D
D
D
D
B
B
B
B
-
a
u = wind speed, mph; x, y, z = downwind, lateral, and vertical distance, ft; time = min;
X = concentration, ug/m3; Q = emission rate in units printed out; S' = stability class.
Respirable particulates (<7 ym geometric mean diameter particles).
emission factors for total particulates and respirable particu-
lates from blasting (E^t and E-^)r) are:
= 4,366 g = 0.56 g
bt 7,716 metric tons metric ton
E
'br
0.003 g
metric ton
Respirable particulates are 1% of the total mass particulate
emitted from blasting.
Truck Loading—
Trucks at the quartzite plant sampled are loaded by shovels and
front-end loaders. Front-end loading was sampled, and two con-
centration values were produced. Using the point source model
(Equation B-6) , emission rates of 4.8 x 10~5 and 8.7 x 10"1* g/s
for respirable and total particulates were computed. It takes
an assumed 1.2 min (0.02 hr) to load a 5.4-metrie-ton truck;
therefore, total particulate and respirable particulate emission
factors from loading (Eit and E±r, respectively) are:
(8.7 x 10"^ gyo.002 hrV
~ V s A truck /\5.
truck
X3,600 s\ 0.01
hr / metri
012 g
metric ton
truck /\5.4 metric tons
E = °-°906 g
lr metric ton
Respirable particulates constitute 5% of the emitted total mass
particulate from loading operations.
42
-------
Transport on Unpaved Roads—
Unpaved road emissions at the quartzite plant were sampled with
emission rates in g/m-s computed from the line source model (Equa-
tion B-8). The average emission rate of total particulates was
2.4 x 10-4 g/m-s. Three truck sizes were used: 5.4-metric-ton,
8.2-metric-ton, and 22.7-metric-ton capacity. The latter two were
used for transport of finished material; the smaller truck was
used for raw (unwashed) quartzite. The raw quartzite truck capac-
ity plus the average of the finished material truck capacities,
22.4 metric tons, represent the average amount of material associ-
ated with transport on unpaved roads. The effective sampling time
is an average of 320 s (0.088 hr) for the four readings after the
initial and final beta count times of the respirable dust monitor
are subtracted (28). Therefore, the total particulate emission
factor from transport (Eft) is:
V2 x 600 mV truck \.. noo
X truck A22.4 metric tons/0'088
__ /2.4 x ICT1* g\/2 x 600 mV truck
Ett
4.1
metric ton
The emission factor for respirable particulates from transport
(E-tr) is calculated from the assumption that 18% of the total par-
ticulates are respirable, based on crushed stone sampling (7) .
Therefore:
E - °'74
Jtr metric ton
Washing and Screening—
One sample was taken of emissions from the washing plant area.
The point source model (Equation B-6) produced an emission rate
of 1.2 x 10"1 g/s. The washing unit processes an average of
57 metric tons/hr of quartzite. The total particulate emission
factor from washing and screening (Ewst) is thus:
(1.2 x 10"1 gW hr \/3,600 s\ = 7.6 g
wst V s /\57 metric tonsA hr / metric ton
Respirable particulates are assumed to be 11% of the total mass
level based on the average percent level from all crushed stone
operations (7). Therefore, the washing and screening respirable
emission factor (Ewsr) is:
E = 0.84 g
Jwsr metric ton
Truck Unloading (En) , Conveying (Ef,) , Crushing (Err) , and
Stockpiles (Es)—
Emission factors for these unit operations are all taken from
crushed stone data, except that for stockpiles which is taken from
43
-------
a study of wind erosion of coal stockpiles. These emission fac-
tors are presented below with the respirable percent in parentheses,
Eut = 0.13 g/metric ton (7)
EUJ. = 0.05 g/metric ton (42%) (7)
E . = 1.73 g/metric ton (7)
£„_ = 0.11 g/metric ton (7%) (7)
Ci
= 13.4 g/metric ton (7)
= 1.34 g/metric ton (10%) (7)
E . = 6.4 g/metric ton-yr (26)
Eov = °-4 g/metric ton-yr (6.3%)(26)
S 3T
The emission factors for crushing (Ecr^- and Ecrr) were based on
sampling of primary crushing at a crushed stone operation. The
overall emission factors for the entire plant (assuming all opera-
tions occur at once) are 3.6 g/metric ton (respirable) and
34.7 g/metric ton.
Free Silica, Trace Elements, and Fibers
The particulates emitted from the crushed quartzite quarry opera-
tion were analyzed for free silica, trace elements, and fibers.
The free silica analysis is presented in Table B-6. The mean
content of free silica is 17%. Free silica is defined as crystal-
line silica, and the most common form of crystalline silica is
quartz. Quartz is also the chief source of free silica in rock
formations. Quartzite is a metamorphic form of sandstone and
therein contains more nonperiodic, random silicon dioxide (Si02)
arrangements, termed amorphic. Amorphorus silica is not classi-
fied as free silica (31). The particulate collected was there-
fore not 100% free silica since it was quartzite rock dust. The
17% free silica content is applied to each unit operation in
determining emission factors applicable to free silica emissions.
Fibers are defined as particles greater than 5 ym in length with
a length-to-width ratio greater than or equal to 3 (32). The
fiber analysis of emissions from the crushers is presented below.
The emission factor for fibers is computed from the point source
(31) Criteria for a Recommended Standard: Occupational Exposure
to Crystalline Silica. NIOSH 75-120, U.S. Department of
Health, Education, and Welfare, Rockville, Maryland, 1974.
121 pp.
(32) Criteria for a Recommended Standard: Occupational Exposure
to Asbestos. HSM 72-10267, U.S. Department of Health, Educa-
tion, and Welfare, Rockville, Maryland, 1972. 89 pp. plus
appendices.
44
-------
TABLE B-6. FREE SILICA ANALYSIS OF EMISSIONS
FROM CRUSHED QUARTZITE QUARRY
Sample Free silica, %
1 8.0
2 17.0
3 24.8
4 17.2
Mean value 17
Standard deviation ±6.9
95% Confidence interval 17 ± 11
Field area = 0.005 mm2
Count =100 fields
Average count per field =18
Ground level concentrations (x = 46 m, y = 0, and z = 0 m
from the source) = 0.02 fiber/cm3
E-, = Emission factor for fibers = 1,360 fibers/metric ton
rb
model (Equation B-6) using high-volume samplers. Elemental
analyses of quartzite particulate emissions from the crushed
quartzite quarry area are shown in Table B-7. These analyses
indicate silicon levels consistent with the free silica levels
detected in the previous sample (see Table B-6). The high level
of lead detected in sample 2 (73.3%, Table B-7) was studied by
determining, through the "Student t" test, the mean of the four
lead samples, 1.02% ± 1.53 standard deviation. The confidence
limit for these four samples is 1.02% ± 2.43 at the 95% level.
Values greater than 3.4% therefore are beyond the upper confi-
dence level, and the probability of the greater than 3.3% value
indicating the true mean is less than 5%, assuming a normal
distribution. The average percentage of the elements in Table
B-7 are used in computing each emission factor from the partic-
ular data.
Nitrogen Oxides and Carbon Monoxide
Emission factors for nitrogen oxides and carbon monoxide emitted
from the blasting operation (EbNOx and Ebco, respectively) are
based on computations performed on experimental investigations by
the Bureau of Mines (23). These values are as follows:
E.vrr, = 2.85 g/metric ton
bNOx
E,-.n =1.68 g/metric ton
45
-------
TABLE B-7.
ELEMENTAL ANALYSES OF QUARTZITE PARTICULATE
EMISSIONS FROM CRUSHERS
Element
Silicon
Calcium
Copper
Iron
Aluminum
Lead
Sodium
Magnesium
Tin
Titanium
Manganese
Nickel
Chromium
Silver
Zinc
Vanadium
Sample 1
5.8 to 17.5
1.2
0.6
0.5
0.4
0.4
0.2
0.2
0.02
0.04
0.04
0.02
0.01
0.006
Negligible
Negligible
Sample 2
3.3 to 10
1.7 to 3.3
1 to 2.0
0.7
0.7
>3.3"
0.2
0.1
0.02
0.03
0.03
0.007
0.02
<0.003
0.20
<0.003
Weight %
Sample 3
6.62 to 19.86
3.31 to 6.62
0.4
3.31 to 6.62
1.32
0.2
0.53
0.13
0.01
0.07
0.03
Negligible
0.01
<0.005
Negligible
<0.005
Sample 4
5.32 to 16
2.66 to 5.32
1.06
1.06 to 2.66
0.43
0.16
0.48
0.16
0.02
0.05
0.04
<0.005
0.01
<0.005
1.06
<0.005
Averag
10.55a
3.16a
0.89a
2.00a
0.71
0.25
0.35
0.15
0.02
0.05
0.04
0.008C
0.01
0.005"
0.32C
0.003C
e
.
.
For samples 1 through 4, average values of ranges were used to compute the
overall average.
b
Value rejected due to use of "t" test discussed in text.
Negligible value = 0.
< value equated to maximum.
EMISSION BURDENS AND GROWTH FACTOR
Emission Burdens
State or national emission burdens for each pollutant refer to
the ratios, expressed as percent, of the annual mass of a par-
ticular pollutant emitted from a source to the total mass of
that pollutant emitted in a state or nationally. These are
referred to as the state and national emission burdens. These
levels are computed for the entire source, not on a unit opera-
tion basis. Emission burdens are computed only for criteria
pollutants (33): total particulates, sulfur oxides (SOX),
nitrogen oxides (NOX), carbon monoxide (CO), and hydrocarbons
(HC). Using the emission factors for these pollutants, the mass
levels listed in Table B-8 (34) are obtained. Mass emissions
per state are the product of the emission factor and production
per state (Table 3).
(33) Air Quality Data - 1972 Annual Statistics. EPA-450/2-74-001,
U.S. Environmental Protection Agency, Research Triangle Park,
North Carolina, March 1974. 137 pp.
(34) 1972 National Emissions Report. EPA-450/2-74-012, U.S.
Environmental Protection Agency, Research Triangle Park,
North Carolina, June 1974. 422 pp.
46
-------
TABLE B-8.
MASS EMISSIONS AND EMISSION BURDENS FROM
SANDSTONE, QUARTZ, AND QUARTZITE SOURCES
Mass emissions
Total participates
State
Alabama
Arizona
Arkansas
California
Colorado
Georgia
Missouri
Montana
New Mexico
New York
North Carolina
Ohio
Oregon
Pennsylvania
South Dakota
Texas
Utah
Vermont
Virginia
Washington
West Virginia
Wisconsin
Other states
SQQ
metric
1.8
17.5
179.7
167.5
6.8
2.6
7.0
12.2
3.5
22.5
2.0
29
5.8
113.2
29.6
33.3
4.8
1.6
23.2
28.1
32
36
86
All
sources
(34)
tons/yr
1,178,643
72,685
137,817
1,006,452
201,166
404,574
202,435
272,688
102,785
160,044
481,017
1,766,056
169,449
1,810,598
52,336
549,399
71,692
14,587
477,494
161,934
213,715
411,558
3,410,426
Percent
<0.001
0.024
0.13
0.017
0.003
0.001
0.003
0.004
0.003
0.014
<0.001
0.002
0.003
0.006
0.057
0.006
0.007
0.011
0.005
0.017
0.015
0.009
0.003
Carbon monoxide
SQQ
metric
0.09
0.85
8.7
8.1
0.33
0.13
0.34
0.59
0.17
1.1
0.1
1.4
0.28
5.5
1.4
1.6
0.23
0.08
1.1
1.4
1.6
1.7
4.2
All
sources
(34)
tonS/yr
1,885,657
815,454
843,204
8,237,667
875,781
2,036,010
1,854,901
611,061
504,249
4,881,922
1,734,398
5,205,719
929,247
3,729,830
387,356
6,897,748
402,527
150,510
1,548,031
1,659,117
494,214
1,582,869
13,400,994
Percent
<0.001
<0.001
0.001
<0.001
<0.001
<0.001
<0.001
<0.001
<0.001
<0.001
<0.001
<0.001
<0.001
<0.001
<0.001
<0.001
<0.001
<0.001
<0.001
<0.001
<0.001
<0.001
<0.001
Nitrogen oxides
SQQ
metric
0.15
1.4
15
14
0.56
0.21
0.57
1.0
0.29
1.8
0.17
2.4
0.48
9.3
2.4
2.7
0.39
0.13
1.9
2.3
2.6
2.9
7.1
All
sources
(34)
tons/yr
397,068
123,871
168,989
1,663,139
147,496
369,817
448,300
148,405
199,181
572,451
412,599
1,101,470
135,748
3,017,345
49,490
1,303,801
80,998
24,286
329,308
187,923
229,598
408,525
4,534,944
Percent
<0.001
0.001
0.009
0.001
<0.001
<0.001
<0.001
0.001
<0.001
< 0.001
<0.001
<0.001
<0.001
<0.001
0.005
<0.001
<0.001
0.001
0.001
0.001
0.001
0.001
<0.001
NATIONAL TOTAL 931
17,872,000
0.005
40.9
96,868,000 <0.001 69.4 22,258,000 <0.001
Includes Connecticut, Idaho, Kansas, Kentucky, Maryland, Michigan, Minnesota, Nevada, New Hampshire,
Oklahoma, Tennessee, and Wyoming.
Growth Factor
The growth factor is the ratio of mass emissions at the present
time to the level expected at the end of 5 years. These levels
are computed from the product of present and future production
rates and the overall emission factor for each criteria pollutant
emitted from the source. The emission levels in Table B-8 are
computed on the basis of 1972 production rates. These emission
levels are converted to present levels from the data presented in
Table 6 (in the text). The emission level in 1982, 5 years from
1977, is also computed from the production data in Table 6.
The 1972 level of mass emissions of total particulates from SQQ
sources is 741.4 metric tons/yr. The present 1977 level is
based on the production quantity presented in Table 6. Emissions
of 1,043 metric tons of total particulates will be generated in
1977.
The levels in 1982 are expected to yield 1,287 metric tons of
total particulates. The ratio of these two values yields the
growth factor (GF):
1,287 metric tons , 2^
G = 1,043 metric tons
47
-------
APPENDIX C
SOURCE SEVERITY AND AFFECTED POPULATION
SOURCE SEVERITIES
Source severity is a variable computed to indicate the hazard
potential of emissions from a source, representative of an indus-
try. Severity is equivalent to a time-averaged maximum downwind
concentration of a pollutant at a representative distance divided
by a hazard factor computed for that pollutant. Mathematical
models are employed to describe the dispersion of pollutants in
the atmosphere. For open sources, such as quarries, the model
employs the concentration of a pollutant occurring at ground
level. This concentration may occur only once a year and be con-
sidered a worst case condition. The hazard factor is derived
from ambient air quality criteria and adjusted threshold limit
values (8).
Concentrations of pollutants downwind of a source are computed
for class C atmospheric (Tables B-2 and B-3) stability using the
point source model (Equation B-6) at an average wind speed. The
instantaneous downwind concentration at distance x is then
corrected to a time-averaged maximum (9). The hazard factor is
a corrected TLV from an 8- to a 24-hr exposure, with a safety
factor of 100 applied. For criteria pollutants, the national
ambient air quality standards are used (33). For free silica,
the TLV equals 10 mg/m3 divided by (2 + % respirable quartz) (6).
Inserting these factors, the severity equations reduce to the
form shown in Table C-l. In these equations, Q is the emission
i^te in g/s, and x is the downwind distance. Severities are
calculated for representative sources at the representative down-
wind distance. The value of Q is a product of the emission fac-
tor for a particular operation (which is determined using other
dispersion models, Appendix B) and the representative "production
rate. For stockpiles, Q is the product of the emission factor
and annual production for the representative plants. The source
severities are computed using the Table C-l relationships.
(35) Blackwood, T. R., and R. A. Wachter. Source Assessment:
Coal Storage Piles. Contract 68-02-1874, U.S. Environmental
Protection Agency, Cincinnati, Ohio, July 1977. 96 pp.
48
-------
TABLE C-l. SEVERITY EQUATIONS (35)
Pollutant
Severity equation
Particulate
S = 4,020 Q
x
1.81
CO
Hydrocarbons
SOX
Other
s = 22'2°o Q
X1.90
44.8 Q
S =
93.40 i
,,1.81
s = 2'B7°
X
S =
1.81
316 Q
(TLV)(x1'81)
(C-l)
(C-2)
(C-3)
(C-4)
(C-5)
(C-6)
The severities for particulates, free silica, fibers, NOX, and CO
are presented in Table C-2.
TABLE C-2.
SOURCE SEVERITY VALUES FOR THE REPRESENTATIVE
SANDSTONE, QUARTZ, AND QUARTZITE SOURCES
Source severity
Unit operation
Drilling
Blasting
Truck loading
Transport on unpaved roads
Washing and screening
Truck unloading
Conveying
Crushing
Stockpiles
TOTAL
Respirable
particulates
0.00005
0.00003
0.00001
0.007
0.008
0.0005
0.001
0.013
0.0003
0.034
Free silica
particulates
0.001
0.0007
0.0002
0.19
0.21
0.013
0.03
0.34
0.008
0.91
Fibers
a
a
a
a
a
a
a
2.2 x 10~7
_a
2.2 x 10~7
NOX
b
0.09
b
~b
b
b
b
b
~b
0.09
CO
b
0.0002
b
~b
b
b
b
b
~b
0.0002
a
No determination made. Not applicable.
Severities for trace elements are determined by using the aver-
age percent of the trace elements detected within particulates.
These percentages are applied to the total emission factors for
respirable particulates from the entire source. The resulting
severities are presented in Table C-3.
49
-------
TABLE C-3.
SOURCE SEVERITIES FOR TRACE ELEMENTS
FROM THE REPRESENTATIVE CRUSHED SAND-
STONE, QUARTZ, AND QUARTZITE SOURCE
Element
Calcium
Copper
Iron
Aluminum
Lead
Sodium
Magnesium
Tin
Severity
0.0173
0.022
0.01C .
0.0017°
0.04 -
0.004T
0.00049
0.0002
Element
Manganese
Nickel
Titanium
Chromium
Gold
Zinc
Vanadium
Severity
0.0002 .
0.00002^
0.00005
0.00056.
O.OOOOlP
0.0007
0.0001
TLV based on calcium oxide, 5 mg/m3.
TLV based on nuisance particulates, 10 mg/m3.
TLV based on iron oxide fume, 5 mg/m3.
TLV based on proposed level, titanium
dioxide, 20 mg/in3 .
A _
TLV based on chromium salts, 0.5 mg/m3.
TLV based on sodium hydroxide, 2 mg/m3.
"TLV based on magnesium oxide fume, 10 mg/m3.
Severity for fibers emitted from SQQ operations was determined
for the crushers sampled. The crusher represents the highest
severity for respirable particulates from a unit operation. At a
TLV of 5 fibers/cm3 (6), the severity is computed as 2.2 x 10~7.
Fibers from other unit operations were not analyzed.
AFFECTED POPULATION
Affected population refers to the number of persons exposed to a
ground level concentration, x> for which \/F>Q.I. Therefore, the
product of the representative population density and the area
where x/F>0.1 will yield an affected population level. The
affected area is established by setting S equal to 0.1 in the
equation (Table C-l) and determining the downwind distance at
which this occurs. This_distance is used to compute the affected
area as the area of the x/F = 0-1 circle minus the area within
the source boundaries.
There is no affected population for respirable particulates where
S is greater than or equal to 0.1 since the total severity from
the representative source is 0.027. Severities are also less
than 0.1 for NOX, CO, fiber, and trace element emissions. How-
ever, for free silica particulates, the severity at the repre-
sentative distance of 410 m is 0.91. The distance at which
50
-------
X/F equals 0.1 is determined by using the emission rate for free
silica particulates in Equation C-7:
0.1 = 316Q _
(TLV) (x1'81)
9 g WO. 126 metric ton
metric ton A s
(2 5
—r-^
metri
TLV = threshold limit value, 10 ^?/m3 +17%
x = unknown
Using these data, the value of x from Equation C-7 is 458 m. The
affected area is thus located between 410 m and 458 m, where
these distances are the radii of concentric circles. Therefore,
the area affected is:
A = rr(458 m)2 - Tr(410 m)2 = 130,825 m2
z
The affected population for free silica emissions based on the
representative population density, 38.8 persons/km2, is
therefore:
A . = (130,825 m2}/38.8 personsW km2. \ = f±ve persons
Pfs \ km2 Al x 106 m2/
51
-------
GLOSSARY
amorphous: Without stratification or other division;
uncrystallized.
ANFO: Ammonium nitrate and fuel oil mixture used as an
explosive.
atmospheric stability class: Coding used to represent the turbu-
lent state of the atmosphere.
azimuth: Horizontal direction expressed as the angular distance
between the direction of a fixed point (as the observer's
heading) and the direction of the object.
chromite: Black mineral, FeCr2Oit, with a metallic luster and
uneven fracture; the chief ore of chromium.
confidence interval: Range over which the true mean of a popula-
tion isexpected to lie at a specific level of confidence.
criteria pollutant: Pollutant for which ambient air quality
standards have been established.
detrital: Relating to fragments or rocks produced by disinte-
gration or wearing away.
dustiness index: Reference used in measuring the amount of dust
settled where a material is dropped in an enclosed chamber.
emission burden: Ratio of the total annual emissions of a pol-
lutant from a specific source to the total annual state or
national emissions of that pollutant.
feldspar: Any of several crystalline minerals comprised mainly
of aluminum silicates.
fibrosis: Abnormal increase in the amount of fibrous connective
tissue in an organ or tissue.
field area: Microscopic area examined for fiber content.
free silica: Crystalline silica defined as silicon dioxide
(SiC>2) arranged in a fixed pattern (as opposed to an amor-
phous arrangement).
52
-------
garnet: Hard, glasslike silicate mineral of various colors.
granite: Very hard igneous rock, usually gray or pink, consist-
ing chiefly of crystalline quartz, feldspar, and mica.
hazard factor: Measure of the toxicity of prolonged exposure to
a pollutant.
igneous: Produced by the action of fire, formed by volcanic
action or great heat.
limestone: Rock consisting mainly of calcium carbonate.
magnetite: Black, iron oxide (Fe30^) which is an important iron
ore.
metasomatic: Relating to metamorphism that involves important
changes in the chemical composition and in the mineral com-
position and texture of rocks.
metamorphic: Changed in structure by pressure, heat, chemical
action, etc.
processing plant: That portion of the source where the operation
of crushing and size classification of stone occurs.
pulverizer: Crusher used to reduce stone size to powder or dust.
pyrite: Iron sulfite, FeS2, a mineral occurring as a native ore.
quarry: Term used to refer to the mining and material transfer
operations.
quartz: Crystalline silicon dioxide, Si02/ occurring in abun-
dance usually in a colorless, transparent form.
quartzite: Massive, hard, light-colored rock with a flinty
sheen; it is a metamorphoses sandstone.
representative source: Source that has the mean emission
parameters.
respirable particulates: Those particles with a geometric mean
diameter of less than or equal to 7 ym.
rutile: Lustrous bark-colored mineral titanium dioxide, Ti02,
commonly found in prismatic crystals and usually containing
iron.
rock: Stone in a mass.
53
-------
sandstone: Common sedimenary rock consisting of sand grains,
usually quartz, cemented together by silica, lime, etc.
sedimentary: Describes matter or mass deposited by wind or water.
severity: Hazard potential of a representative source defined as
the ratio of time-averaged maximum concentration to the
hazard factor.
silicosis: Chronic disease of the lungs caused by the continued
inhalation of silica dust.
sizing screen: Mesh used to separate stone into various sizes.
stone: Hard, solid, nonmetallic mineral matter of which rock is
composed.
threshold limit value: Concentration of an airborne contaminant
to which workers may be exposed repeatedly, day after day,
without adverse effect.
zircon: Silicate of zirconium, ZrSiO^, occurring in tetragonal
crystals.
54
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TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
REPORT NO.
EPA-600/2-78-004n
3. RECIPIENT'S ACCESS!ON-NO.
4. TITLE AND SUBTITLE
SOURCE ASSESSMENT: CRUSHED SANDSTONE, QUARTZ, AND
QUARTZITE, State of the Art
5. REPORT DATE
May 1978 issuing date
6. PERFORMING ORGANIZATION CODE
. AUTHOR(S)
P. K. Chalekode, T. R. Blackwood, and R. A. Wachter
8. PERFORMING ORGANIZATION REPORT NO.
MCR-DA-745
9. PERFORMING ORGANIZATION NAME AND ADDRESS
Monsanto Research Corporation
1515 Nicholas Road
Dayton, Ohio 45407
10. PROGRAM ELEMENT NO.
1BB610
11. CONTRACT/GRANT NO.
68-02-1874
12. SPONSORING AGENCY NAME AND ADDRESS
Industrial Environmental Research Laboratory—C4im»r OH
Office of Research and Development
U. S. Environmental Protection Agency
Cincinnati, Ohio 45268
13. TYPE OF REPORT AND PERIOD COVERED
Task Final, 3/75-7/77
14. SPONSORING AGENCY CODE
EPA/600/12
15. SUPPLEMENTARY NOTES
IERL-Ci project leader for this report is John F. Martin, 513/684-4417.
16. ABSTRACT
This report describes a study of atmospheric emissions from the crushed sandstone,
quartz, and quartzite industry. Particulates are emitted from drilling, blasting,
loading and unloading trucks, transport on unpaved roads, washing, crushing,
screening, conveying, and stockpiling. The emission factor for respirable particu-
lates from processing is 3.6 g/metric ton; washing, screening, crushing, and
vehicular movement on unpaved roads contribute approximately 80% of the value.
Free silica is the hazardous constituent of the emitted dust. Emission factors
for carbon monoxide, nitrogen oxides, and fibers are 1.68 g/metric ton, 2.85 g/metric
ton, and 1,360 fibers/metric ton, respectively. In order to evaluate the potential
environmental effect of this industry, source severity was defined as the ratio
of the maximum ground level concentration of an emission to be ambient air
quality standard for criteria pollutants or to a modified TLV for noncriteria
pollutants. The maximum source severity due to respirable free silica emission
from a representative plant is 0.91. Air pollution control is not widely applied
to emissions from crushed sandstone, quartz, and quartzite operations.
17.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.lDENTIFIERS/OPEN ENDED TERMS
c. COSATI Field/Group
Air pollution
Sandstones
Quartz
Quartzites
Aggregates
Silicon dioxide
Carbon monoxide
Nitrogen oxide
Fibers
Air Pollution Control
Stationary Sources
Source Severity
Particulate
68A
18. DISTRIBUTION STATEMENT
RELEASE TO PUBLIC
19. SECURITY CLASS (ThisReport)
UNCLASSIFIED
21. NO. OF PAGES
fiQ
20. SECURITY CLASS (Thispage)
UNCLASSIFIED
22. PRICE
EPA Form 2220-1 (9-73)
55
U. S. GOVERNMENT PRINTING OFFICE: 1978-757-140/1349 Region No. 5-11
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