United States
Environmental Protection
Agency
Industrial Environmental Research
Laboratory
Research Triangle Park NC 2771 1
EPA-600/2-79-074
SW-740
April I979
Research and Development
Environmental and
Resource Conservation
Considerations of Steel
Industry Solid Waste
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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.
EPA REVIEW NOTICE
This report has been reviewed by the U.S. Environmental Protection Agency, and
approved for publication. Approval does not signify that the contents necessarily
reflect the views and policy of the Agency, nor does mention of trade names or
commercial products constitute endorsement or recommendation for use.
This document is available to the public through the National Technical Informa-
tion Service, Springfield, Virginia 22161.
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EPA-600/2-79-074
SW-740
April 1979
Environmental and Resource
Conservation Considerations
of Steel Industry Solid Waste
by
V.H. Baldwin, M.R. Branscome, C.C. Allen,
D.B. Marsland, B.H. Carpenter, and R. Jablin
Research Triangle Institute
P.O. Box 12194
Research Triangle Park, North Carolina 27709
Contract No. 68-02-2612
Task No. 73
Program Elements No. 2DB662, 1AB604, and 1BB610
EPA Project Officers:
John Ruppersberger William J. Kline
Industrial Environmental Research Laboratory Office of Solid Waste
Office of Energy, Minerals, and Industry Washington, D.C. 20460
Research Triangle Park, NC 27711
Prepared for
U.S. ENVIRONMENTAL PROTECTION AGENCY
Offices of Research and Development and Solid Waste
Washington, DC 20460
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FOREWORD
The iron and steel industry generates a wide variety of solid wastes.
Iron and steelmaking plants, containing process facilities such as coke plants,
blast furnaces, steelmaking furnaces, and steel finishing operations, generate
slags, sludges, scales, and dusts. The different types of solid waste which
are generated vary widely in their potential environmental hazard.
As a result of implementation of the Clean Air Act, the Clean Water Act,
the Resource Conservation and Recovery Act, and other Federal and State laws
regarding public health and the environment, solid wastes have become an
increasing concern. EPA is committed to a solid waste management program that
will not only protect public health and the environment but will maximize the
use/reuse of waste materials. Specifically, management technologies which
recycle solid waste and thereby contribute to energy and resource conservation
are actively encouraged.
The purpose of this report is to identify the origins, nature, and quan-
tities of solid wastes generated in the iron and steel industry as well as
characterize the current waste disposal practices and resource recovery poten-
tial of the wastes. Special emphasis has been given to potential changes and
alternatives to current industry practice which may increase resource recovery
and reduce the environmental impact of solid waste disposal.
Steffeft Plehn
Deputy Assistant Administrator
for Sol id Waste
Burchard
)irector, Industrial
Environmental Research Laboratory/RTF
111
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ABSTRACT
This report examines the solid wastes generated by the iron and steel
industry relative to the impact of Section 4004 of the Resource Conservation
and Recovery Act. The quantities, properties, and origin of wastes are
estimated using flow diagrams, material balances, and generation factors. Of
the estimated 140 million metric tons of solid waste (including in-plant mill
scrap) produced annually, 80 percent is either recycled or reused.
Waste disposal practices are discussed, and a potential for groundwater
pollution is identified. The capital cost to collect leachate from non-
hazardous wastes which could potentially endanger the groundwater is estimated
to increase the current landfill costs by 40 percent, but this cost is less
than one percent of the estimated future overall environmental cost.
IV
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TABLE OF CONTENTS
FOREWORD iil
ABSTRACT iv
FIGURES ix
TABLES xi
ABBREVIATIONS AND DEFINITIONS xv
ACKNOWLEDGEMENT xvi
1.0 SUMMARY 1
2.0 INTRODUCTION 4
3.0 CONCLUSIONS 5
4.0 RECOMMENDATIONS 6
5.0 INDUSTRY CHARACTERIZATION 7
5.1 Description of the Steelmaking Processes 7
5.2 Industry Overview 14
5.2.1 Number of Plants 14
5.2.2 Size and Capacity Distribution 14
5.2.3 Geographic Location of Plants 15
5.3 General Economic Status of the Industry 15
5.3.1 Capital Expenditures by the Steel Industry 24
5.3.2 Status of the Six Largest Integrated Steel
Producers 24
U.S. Steel 24
Bethlehem Steel 27
National Steel 28
Republic Steel 28
Armco Incorporated 29
Inland Steel 30
Pollution Control Expenditures 31
6.0 WASTE CHARACTERIZATION 33
Representative Iron and Steel Plant 34
6.1 Analysis of Processes that Generate Waste 36
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TABLE OF CONTENTS (cont'd)
7.0
6.1.1 By-Product Coking
6. .2 Sintering
6. .3 Blast Furnace Ironmaking
6. .4 Basic Oxygen Steelmaking
6. .5 Electric Arc Steelmaking
6. .6 Continuous Casting and Primary Rolling
6. .7 Hot and Cold Rolling
6. .8 Finishing Operations
6.2 Magnitude of Solid Waste Generation
6.2.1 National Solid Waste Generation
6.2.2 Slags
6.2.3 Iron Oxide Solid Waste
6.2.4 Solid Waste Generation by State
6.2.5 Solid Waste Generation by Geographical Region
6.3 Solid Waste Projections
6.3.1 Effect of Air Regulations
6.3.2 Effect of Water Regulations
6.3.3 Effect of Industry Growth
THE ENVIRONMENTAL IMPACT OF IRON AND STEEL SOLID WASTES
7.1 Treatment and Disposal Practices
7.1.1
7.1.2
7.1
7.1
.3
.4
.5
Slag Treatment and Disposal
Sludge Treatment and Disposal
Dust Treatment and Disposal
Scale Treatment and Disposal
7.1.5 Miscellaneous Waste Treatment and Disposal
7.2 Current Disposal Facilities
7.2.1 Prevalence of Types of Disposal Practices
7.2.2 Estimate of the Number of Landfills
7.2.3 Present Disposal Costs
7.3 Environmental and Health Assessment of Current Disposal
Practices
7.3.1 Water Quality Requirements of RCRA
7.3.2 Water Extraction of Solid Waste Materials
7.3.3 General Information on Soil Attenuation and
Leachate Movement
7.3.4 Groundwater Analysis from Iron and Steel
Landfills
7.3.5 Descriptions of Selected Steel Industry Dump
Sites
37
39
39
43
45
45
47
50
52
52
53
60
66
66
71
72
74
74
77
78
78
80
82
83
83
85
85
86
87
89
90
91
95
101
110
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TABLE OF CONTENTS (cont'd)
Page
7.4 Impact of Section 4004 RCRA Criteria 114
7.4.1 Landfill Site Monitoring for Enforcement of
Groundwater Standards 116
7.4.2 Model Facility 120
7.5 Alternative Disposal Practices for the Iron and
Steel Industry 133
7.5.1 Sole Source Aquifers 134
7.5.2 Waste Separation 134
7.5.3 Artificial Liners 136
7.5.4 Surface Waters 137
7.5.6 Flood Plains 138
7.5.7 Safety 139
7.5.8 Other Criteria 139
8.0 IRON AND STEEL RECOVERY AND RECYCLING 140
8.1 Waste Treatment and Recycle 141
8.1.1 Coke Plant Wastes 141
8.1.2 Iron and Steelmaking Slags 142
Air-Cooled Slag 142
Granulated Slag 144
Expanded Slag 145
Steel Slag 145
8.1.3 Iron Oxide Recycling 147
Agglomeration Processes 148
Direct Reduction Processes 151
De-oiling 155
8.1.4 Waste Pickle Liquor 156
Acid Regeneration 157
Acid Recovery 158
Hydrochloric Acid Regeneration 158
Spray Roaster Type Process 159
Fluidized Bed Roaster 159
Sliding Bed Regeneration 159
Operational Aspects of Regeneration 160
8.1.5 Scrap Recovery 161
8.2 Effect of Process Changes on Waste Production 162
8.2.1 Changes Not Reduced to Practice 163
8.2.2 Processes Not Widely Used 165
8.2.3 Processes in Substantial Current Use 165
vii
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TABLE OF CONTENTS (cont'd)
Page
8.2.4 Description of Process Changes 166
Blast Furnace Burden Preparation 167
Fuel Injection in the Blast Furnace 168
Dehumidification of the Blast 169
External Desulfurization of Iron 169
Direct Reduction of Iron (DRI) 174
Preheating Scrap for Steelmaking 179
Superheating Molten Iron for the BOF 179
Replacement of Open Hearth Furnaces 181
Continuous Casting 181
8.2.5 Effect of Process Changes on the Model Plant 182
Analysis of Process Changes 183
Analysis of Resource Consumption 185
Analysis of Solid Waste Generation 192
8.2.6 Future Iron and Steelmaking 192
8.3 New Direction Suggested by Recent U.S. Patents 193
8.3.1 Blast Furnace Slag 195
8.3.2 Steelmaking Slags 196
8.3.3 Blast Furnace Dust and Sludge 196
8.3.4 Steelmaking Dust and Sludge 197
8.3.5 Rolling Mill Wastes 198
REFERENCES 199
INDEX 207
viii
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FIGURES
Figure Page
1 Flow diagram for a typical 2.5 Megatonne plant 8
2 Diagram of a blast furnace 10
3 Size and capacity cumulative distributions of two types of
steel plants 16.
4 Size distribution of companies that account for ~ 90%
national capacity (raw steel) by company 17
5 Raw steel capacity of integrated companies 18
6 Raw steel capacity by EPA region 19
7 Distribution of iron and steelmaking facilities 20
8 Cash flow of the steel industry compared to other industries 21
9 Waste production from typical plant with 2,500,000 tonnes of
steel per year 35
/
10 Material flow for coke plant in production of 2,500,000
tonnes of steel per year 38
11 Material flow for sinter plant in production of 2,500,000
tonnes of steel per year 40
12 Blast furnace material flow in production of 2,500,000 tonnes
of steel per year 42
13 Basic oxygen process material flow in production of 2,500,000
tonnes of steel per year 44
14 Electric arc furnace material flow in production of 500,000
tonnes of steel per year 46
15 Continuous casting, soaking, primary rolling material flow
in production of 2,500,000 tonnes of steel per year 48
16 Hot and cold rolling in production of an overall total of
2,500,000 tonnes of steel per year 49
17 Tin plating, galvanizing material flow for 2,500,000 tonnes
of steel per year 51
18 Illustration of relationships within the hydrologic system 102
19 Abandoned gravel pit with a clay layer at its base 103
20 Diagram of a sanitary landfill with leachate collection 121
ix
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FIGURES (cont'd)
Figures Page
21 Cost factors for various landfill sizes 126
22 The cost of waste impoundment as a function of the number
of years of landfill capacity for three rates of waste
generation 127
23 Annual costs of capital for optimum sized landfills for
various rates of waste generation 128
24 Waste-dust grate-kiln direct reduction process flowsheet 152
25 Two versions of the injection process for direct steelmaking 164
26 Sulfur balance for a typical blast furnace 171
p
27 Ground plan of Mag-coke desulfurizing plant 172
28 Schematic representation of the desulfurizing facilities of
the torpedo-top-injection method 173
29 Schematic flow diagram of the Midrex Process 175
30 Flowsheet of the Midrex Process 175
31 Continuous casting, soaking, primary rolling material flow
in production of 2,500,000 tonnes of steel per year 184
32 Electric arc furnace material flow in production of
500,000 tonnes of steel per year 186
33 Basic oxygen process material flow in production of
2,50*0,000 tonnes per year of steel 187
34 Blast furnace material flow in production of 2,500,000
tonnes of steel per year 188
35 Material flow for coke plant in production of 2,500,000
tonnes of steel per year 189
36 Waste production from typical plant with 2,500,000 tonnes
of steel per year 190
37 Melt shop, caster, rolling mill layout for 100,000 ton per
year facility 194
38 Cast billet, intermediate shapes, and finished round 194
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TABLES
Table Page
1 Capacity Estimates by Process 14
2 Gross Income 22
3 Imports: % of Domestic Consumption 22
4 Summary of Financial Statements 23
5 Financial Summary of Six Integrated Steel Companies 24
6 Comparison of Financial Ratios 26
7 United States Steel 27
8 Bethlehem Steel 28
9 National Steel 29
10 Republic Steel 29
11 ARMCO 30
12 Inland Steel 31
13 Pollution Control Expenditures 32
14 Individual Process Outputs for Production of 125,000,000
Tonnes of Steel Per Year 53
15 Waste Generation Factors and Quantities for a Typical
2,500,000 Tonne Year/Plant 54
16 Nationwide Waste Generation for 125,000,000 Tonnes of
Steel Per Year 56
17 Summary of Waste Generation for 125,000,000 Tonnes of Steel
Per Year ' 57
18 Iron and Steelmaking Slags 59
19 Chemical Analysis of Blast Furnace Dusts 61
20 Composition of Blast Furnace Sludge 62
21 Chemical Analyses of EOF Residues—Sands 63
22 Chemical Analyses of BOF Residues—Fines 64
23 Estimated State Distribution of Iron and Steel Capacity 67
24 Estimated State Distribution of Wastes Generated From
125,000,000 Tonnes Steel Production 68
x.i
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TABLES (cont'd)
Table Page
25 Waste Generation by Geographical Region 69
26 Iron Oxide Wastes Available for Regional Treatment (Not
Presently Recycled) 70
27 Order of Magnitude Estimate of Regional Plant Economics 70
28 Estimated Dust Generation to Air Under Present Controls 73
29 Impact of Future Air Regulations on Solid Waste 73
30 Impact of Future Water Regulations on Solid Waste 75
31 Projected Waste Generation in 1983 75
32 Quantity of Slag Sold and Value (1976) 79
33 Slag Disposition From 125,000,000 Tonnes of Steel Per Year 80
34 Quantities of Slag at Selected Sites 80
35 Sludge Disposition From 125,000,000 Tonnes of Steel Per Year 81
36 Dust Disposition From 125,000,000 Million Tonnes of Steel
Per Year 82
37 Scale, Disposition from 125,000,000 Tonnes of Steel Per
Year 83
38 Estimate of Major Landfills 87
39 Landfill Costs 87
40 Cost Estimate of Present Disposal 89
41 A Listing of Permissible Criteria of Selected Leachate
Components for Public Water Supplies 91
42 Results of Aqueous Extraction Tests of Coke Plant Wastes 93
43 Results of Aqueous Extraction Tests of Iron and Steel Slags 94
44 Results of Aqueous Solubility Tests of Iron and Steel Sludges 96
45 Results of Aqueous Solubility Tests of Iron and Steel Dusts 97
46 Results of Aqueous Solubility Tests of Miscellaneous Iron
and Steel Wastes 98
47 Selected Leachate Components in the Groundwater of Various
Iron and Steel Waste Landfills 104
48 Analysis of Groundwater from the Property Boundary (E,l) 106
49 Analysis of Groundwater from Valley Well Below Slag Dump (E,2) 106
xii
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TABLES (cont'd)
Tables Page
50 Analysis of Seepage Spring Water from a Dumpsite (A,7) 107
51 Polynuclear Aromatic Fluorescence Analysis 107
52 Water Pollutants of Environmental Concern in Groundwater
Seepage Site A 108
53 Water Pollutants of Environmental Concern Detected in a Well
at the Base of a Slag Dump Site E 109
54 Water Pollutants of Environmental Concern at the Property
Boundary of an Iron and Steel Landfill Site E 109
55 A Comparison of Pollutant Levels in a Stream Flowing Through
a Large Iron and Steel Landfill Site E 110
56 Water Pollutants Common to Five Water Samples from Two Iron
and Steel Landfill Sites 111
57 Summary of Estimated 4004 Criteria Costs 115
58 Cost Factors for Surveying and Monitoring a Typical Two
Acre Site 119
59 The Cost of Landfill Liners for Various Sized Landfills 123
s
60 Landfill Costs for Nonhazardous Waste Leachate Collection
and Removal 124
61 Cost Factors for the Model Impoundment Facility 125
62 Capital Cost to Line Landfills for Various Production
Segments of the Iron and Steel Industry 130
63 Capital Cost to Line Landfills for Various Production
Segments of the Iron and Steel Industry 131
64 A Summary of the Yearly Capital Cost to Construct Lined
Landfill Facilities for Iron and Steel Wastes (Steelmaking
Slags Excluded) 132
65 A Summary of the Yearly Capital Cost to Construct Lined
Landfill Facilities for Iron and Steel Wastes (Steelmaking
Slags Included) 132
66 Office of Solid Waste List of Hazardous Iron and Steel Wastes 135
67 Uses of Air-Cooled Blast Furnace Slag (1976) 143
68 Uses of Granulated Blast Furnace Slag (1976) 144
69 Uses of Expanded Blast Furnace Slag (1976) 145
70 Steel Slag Uses (1976) 147
71 Cost Estimate for Waelz Process 155
xi-ii
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TABLES (cont'd)
Table Page
72 Use of Direct Reduced Pellets in EAFs 176
73 Direct Reduction Installations in North America 177
74 Implementation and Development of Direct Reduction (DR)
Processes 178
75 Regional Distribution of Direct Reduction Plants and
Projects 178
76 Effect of Superheat on Typical BOF Materials Balance and
Production 180
77 Effect of Process Changes 191
xiv
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ABBREVIATIONS AND DEFINITIONS
BF Blast Furnace
BFHM Blast Furnace Hot Metal, i.e., molten iron as produced by the
BF
BOF Basic Oxygen Furnace
BOP Basic Oxygen Process - refers to the BOF or Q-BOP method of
steelmaking
EAF Electric Arc Furnace
Megatonne Specifies one million metric tons
OH Open Hearth Furnace
Q-BOP A special type of BOF with oxygen blown through holes in the
bottom of the furnace
RCRA Resource Conservation and Recovery Act of 1976
Tonne Specifies a metric ton of 1000 kg
x,v
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ACKNOWLEDGEMENT
This report presents the results of work performed under EPA Contract 68-
02-2612, Task 73. The major funding for this work was provided by the Office
of Solid Waste with the balance from the Industrial Environmental Research
Laboratory, Research Triangle Park. The purpose of this work is the deter-
mination of the nature and quantities of waste residues in the iron and steel
industry. The research was conducted in the Energy and Environmental Research
Division of the Research Triangle Institute. Vaniah H. Baldwin served as the
Project Leader. Members of the Industrial Process Studies Section who
participated in the development and presentation of the findings include:
Marvin R. Branscome, C. Clark Allen, David B. Marsland, David W. Coy, and Ben
H. Carpenter. Richard Jablin, Jablin & Associates, prepared the basic process
characterizations and process modifications to reduce waste quantities.
The valuable assistance of Mr. Charles Duritsa of the Pennsylvania
Department of Environmental Resources—Pittsburgh Office—was greatly
appreciated. Also the help and cooperation of many individuals in various
steel companies is acknowledged.
John Ruppersberger served as the EPA Project Officer, a responsibility
which was shared by OSW's Jan Auerbach and William Kline. The guidance and
direction of these three individuals is gratefully acknowledged.
Further, we acknowledge the American Iron and Steel Institute for their
thorough review of this report.
xvi
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1.0 SUMMARY
The iron and steel industry is characterized by the number of batch
processes which are both labor and capital intensive. The decline in profit
margins, together with the estimated cost of environmental control requirements,
could limit the industry's ability to expand to meet the projected steel
demand. The cost of environmental control requirements for air and water
greatly exceed, the current cost of environmental control for solid waste
disposal facilities.
The iron and steel industry produces an estimated 140 million annual
tonnes of waste (including metallic scrap) approximately 80 percent of which
is currently either recycled or reused.
Large integrated iron and steel plants contain coke plants and blast
furnaces which produce sludges, slags, dusts, and organic wastes. Also,
these different wastes vary widely in their potential environmental hazard.
For example, certain coke plant wastes are hazardous due to their polycyclic
organic content, whereas the blast furnace slag is relatively inert. In
addition, the form of the various wastes are distinctly different including
scrap metal, bricks, slag, sludges, dusts, and liquids. Requirements for
waste transportation and disposal as well as recycle and reuse depend upon
these physical waste characteristics.
Most of the iron and steel wastes which are currently neither recycled
nor reused are deposited in facilities which do not provide for leachate
collection. Most of the disposition of nonhazardous waste is on-site with
approximately 30 percent off-site and 6 percent handled by contract disposal.
The groundwater under some of these sites is not suitable for drinking due to
dissolved solids, oil, pH, ammonia, chromium, manganese, phenols, cadmium, and
other components. Many of these components have been identified through
various water extraction procedures on the individual wastes. The water
extracts for almost every type of iron and steel waste contained materials
which could make the groundwater unfit for human comsumption.
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There are substantial differences in the landfill requirements for hazardous
and nonhazardous wastes. Considering only the potential for groundwater
endangerment at the property boundary (unfit for human consumption, among other
criteria) of previously unendangered groundwater, a hazardous waste can possess
a significant probability of groundwater endangerment, and liners are required
for disposal. Some nonhazardous wastes may possess the potential for groundwater
endangerment and landfill liners may be appropriate to protect the groundwater
at those sites. If the management of the sanitary landfill elects not to use
effective liners and groundwater monitoring indicates endangerment of the
groundwater as a result of the landfill operations, either closure of the
landfill site, corrective procedures, or legal exemption is required. Closure
and corrective action are expensive alternatives and would tend to encourage
the use of liners for some nonhazardous wastes.
The use of lined landfills for steel wastes with controlled discharge of
the collected leachate was assumed for calculating Section 4004 compliance in
this report, since this method of landfill operation would restrict the
contamination of groundwater by the leachate. Excluding blast furnace slag,
bricks, and rubble, proper landfill management under the Resource Conservation
and Recovery Act of 1976 CRCRA) for nonhazardous wastes will increase the
current cost of disposal ($58 million) by $21 million, an increase of 40 per-
cent. This is less than one percent of estimated future air and water pol-
lution controls. On this basis it is expected that the compliance of the
steel industry with Section 4004 RCRA criteria will have little impact on
overall steelmaking economics.
If the lined landfill ing of steelmaking slag is required, this would
increase disposal costs by $1.50 per tonne. This additional cost of disposal
is comparable to the value of steel slags for construction purposes and should
provide an additional economic incentive toward the use of steel slag rather
than the disposal of it. Additional economic incentives for more extensive
recycling of iron oxide wastes is also expected. 'The industry is also starting
to direct its efforts toward some more basic changes in steelmaking which will
provide more continuous processing and greater enclosure of the processes.
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These improvements in steelmaking processes will increase the efficiency of
production as well as reduce environmental problems including the generation
of solid waste.
The iron and steel industry has accumulated enormous quantities of solid
waste from its operations in former years. Because of the large volume
involved, it would not be economically feasible to relocate these wastes to a
lined landfill. The alternative would be to prepare the surface of the
existing disposal pile in such a manner as to retard or prevent the infiltra-
tion of surface waters. Acceptable methods would include grading, paving,
etc. Costs to accomplish this have not been included in the report because
they will have to be determined on a site-by-site basis.
Iron oxide wastes create the most difficult disposal problems because of
their physical size and chemical contaminants. At present, of the 14,000,000
tonnes generated annually, only 55 percent is recycled. The barrier to in-
plant recycling is essentially that of economic feasibility. In certain
portions of the country, regional treatment plants may be profitable; however,
anti-trust regulations present a legal obstacle.
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2.0 INTRODUCTION
The U. S. Environmental Protection Agency is required, under RCRA (PL
94580), to characterize and provide minimum criteria for industrial solid
waste management practices. The study of the iron and steel industry is in
support of these requirements.
In assessing the magnitude of the solid waste disposal problem and
determining the areas of greatest urgency, several topical concerns must be
addressed. These include:
1. Industry characteristics—the number of firms and plants,
their size, location distribution, products, and general
economic status.
2. Waste characteristics—identification and description of
all wastes generated by the iron and steel industries
including each waste stream and intermedia transfers and
the use of this information in pinpointing a representative
iron and steel plant.
3. Treatment and disposal—descriptions of present treatment
and disposal practices, analysis of the prevalence of on-
site vs. off-site disposal, assessment of the impact of
Section 4004 RCRA criteria, the impact of current air and
water regulations, and evaluation of alternative disposal
practices for the industry.
4. Industrial waste recovery—identification of current
practices and assessment of methods, including patents,
in which industrial waste can be recovered, such as energy,
raw material resource, etc., and volume of wastes produced,
and/or alter its form so as to have a lesser impact on the
environment, and enhance resource conservation and resource
recovery.
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3.0 CONCLUSIONS
1. Although most iron and steel wastes are not listed as hazardous, the
available leachate testing data indicate that leachate control is
needed to protect the groundwater for almost every type of iron and
steel waste. The data indicate that leachate is produced which is
unfit for human consumption and can, therefore, potentially endanger
the groundwater.
2. Most iron and steel wastes are currently deposited in facilities which do
not provide for leachate collection.
3. Proper landfill management under RCRA for nonhazardous iron and steel-
making wastes, using leachate collection would cost approximately 40
percent more than current landfill methods, but is relatively low in
cost when compared to air and water pollution control.
4. There is substantial variability in the potential for environmental
endangerment among the various producers within the same waste classi-
fication. This is consistent with differences in raw materials,
process variables and type of product.
5. Technology has been developed to recycle or use most iron and steel
wastes. Approximately 80 percent are currently either recycled or reused.
6. Iron oxide wastes present the greatest difficulties in recycling.
Approximately 55 percent are currently recycled.
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4.0 RECOMMENDATIONS
1. An investigation of the effects of raw material quality and process
variables on iron and steel waste characteristics should be undertaken
to identify the origins of the hazardous components of wastes. For
example, alkali in ore can cause cyanide formation in the reducing
conditions of blast furnace operation. A centrally sponsored program
would avoid costly duplication of effort.
2. The organic components of certain iron and steel wastes which can be
leached should be identified, due to the possibility of polycyclic
organic materials in those extracts.
3. Sources of low volume, perhaps intermittent, wastes should be identified
so that those wastes can be characterized.
4. Extraction testing should be conducted on iron and steel wastes.
Current data are incomplete.
5. Hazardous wastes such as coke plant tar should not be placed with non-
hazardous wastes in lined landfills. This practice could conceivably
require expensive treatment of leachate and any liner failure could be
hazardous.
6. Investigation into economical methods of accomplishing in-plant recycling
of iron oxide wastes should be undertaken. Methods would include de-
oiling the waste, dezincification, and agglomeration.
7. Legal barriers to regional plants for treating iron oxide wastes should
be removed.
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5.0 INDUSTRY CHARACTERIZATION
5.1 DESCRIPTION OF THE STEELMAKING PROCESSES
This study is concerned with the entire sequence of steelmaking opera-
tions beginning with the coke ovens and ending with hot and cold rolling into
finished products.
Figure 1 is a flow diagram for a typical integrated 2.5 megatonne plant,
that is, a plant producing 2.5 million metric tonnes of steel per year.
Although ironmaking begins with the blast furnace, one of the raw materials
charged into the blast furnace is coke and, therefore, the coke oven is
indicated as the starting point for any sequential examination of the overall
process.
Coking is carried out in brick ovens averaging 45 centimeters wide, two
to six meters high and 10 to 15 meters long. Up to 100 ovens are built
together forming a coke oven battery. Finely ground coal is charged into the
oven through a system of fill holes, which are then sealed with lids. The
charge is baked at about 1,100°C for about 18 hours. Volatile chemicals are
removed from the coal and a porous solid mass of carbon remains. The chemi-
cals driven from the coal exit the oven through standpipes. These pipes join
a main which conveys the products to the gas by-product processing plant.
Here the by-products are removed as oils, tars, pitch, and ammonia, and the
cleaned gas is utilized as fuel. At the end of the cokemaking cycle, the
doors are removed from the oven, the coke is pushed out and quenched with
water. The processing and handling of coke produces a fine powder referred to
as coke breeze. The coke itself presents no environmental problem, although
certain plants have a solid waste problem with coke breeze when adequate
facilities for utilizing it are unavailable. Significant hazardous waste
problems arise in the coke by-product plant, however, where waste streams
contain polycyclic aromatic compounds and other carcinogenic materials.
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Coal
On
Flux
dust recycled to sinter
Scrip
1.002.700
.Sbg
'Sludge
ELECTRIC
ARC
FURNACE
•Stag
Dun
Steel
500.000
2,500,000 S Scrap
• Salt
Shapes 1.350.000
Shapes 790.000
Shape*
2.HO.OOO
1.900.000
Salts 240.000
HOT
ROLLING
.Sludge
.Seal*
• Scrap
1.800.000
_•> Sales 1.098.000
702.000
COLD
ROLLING
. Sludge
. PicktoWaiK
700.000
(Z038 Mcgatomn tteel a>a
-------
The blast furnace design In present use originated around 1870; however,
operating practices in the past 20 years have changed, resulting in a tripling
of its output. The greatest change is the utilization of sinter and pellets.
Sinter is a mixture of powdered iron ore and other iron containing dust,
limestone, and coke breeze burned on a moving grate, forming lumps of fused
material suitable for blast furnace charging. Pellets are agglomerated pieces
of iron ore or concentrate that can be sized before charging to the blast
furnace.
The blast furnace is the ironmaking system for the steel plant. It is
loaded from the top with pelletized iron ore, sinter, limestone and other
fluxing substances, and coke (Figure 2). A blast of very hot air, sometimes
enriched with oxygen and fuel oil or gas, is blown into the bottom of the
furnace and a complex set of chemical reactions result in the production of
molten iron containing 3 1/2 to 4 percent dissolved carbon. The molten
product is blast furnace hot metal (BFHM). In some cases, BFHM is poured into
molds to make small ingots of metal referred to as pig iron. The limestone
and fluxing agents melt and react with or otherwise trap the sand, coal ash,
and other impurities to form a slag that amounts to 20 to 40 percent of the
quantity of metal produced. Slag is a secondary product from the blast
furnace and is currently used primarily as road bed and construction fill.
The blast of hot air through the furnace carries a great deal ofdust out
with it. This blast contains carbon monoxide and is valuable as a fuel.
Utilization of the offgas as a fuel to preheat the blast air requires that the
dust be completely removed, therefore, blast furnace dust does not appear as
an uncontrolled"emission. Since this dust contains many raw materials of
value, it is recycled to the sinter plant where it is reincorporated with the
raw material input to the furnace.
The steelmaking processes involve the removal of carbon from the blast
furnace hot metal to below 2 percent, in some cases below one-tenth percent.
It may also involve the addition of other metals to form specialized alloys.
The major reactor for producing steel from hot metal is the basic oxygen
furnace (BOF).
The BOF, a relatively recent development, is a pear-shaped vessel about
10 meters in diameter. The furnace is charged with up to 30 percent scrap
-------
— Stack
Figure 2. Diagram of a blast furnace.
metal, the balance being hot metal from the blast furnace, with some fluxing
materials, as necessary. A lance is lowered to just above the surface of the
metal, and oxygen is blown at supersonic velocities. In 12 minutes to an
hour, depending on furnace design, the carbon, sulfur, and silicon are burned
out of the hot metal and steel is formed. This process emits tremendous
quantities of dust and fume and is equipped with air pollution controls. Dust
laden air is collected in hoods and the dust is removed. If dry control
techniques are utilized, the waste stream is in the form of dust. This dust
is typically very fine and, therefore, difficult to recycle. If a wet control
system is used, the dust appears as a sludge waste stream. The slag output
10
-------
of the BOF is a waste problem, as it is not immediately suitable for some
construction fill purposes due to its potential for expansion. Often some of
the slag is recycled to the blast furnace because of its iron, manganese, and
lime content. The Q-BOP is a modification of the BOF, in which oxygen is
blown through the metal from tuyeres located in the bottom of the furnace.
The electric arc furnace (EAF) is the second major producer of steel.
This furnace is a refractory-lined vessel with three graphite electrodes mounted
vertically that can be lowered into it. The EAF is a flexible device that can
be utilized with oxygen lancing and other techniques to produce steels from
scrap or hot metal, or to produce high purity steels and alloys. The majority
of EAF charges do not involve hot metal but consist solely of scrap steel. A
small amount of limestone flux is also added to the furnace, thereby producing
a slag waste stream. Dust is evolved from the furnace to a degree that
requires air pollution control equipment—usually a dry collection system.
The EAF dust is apt to be particularly high in zinc and other toxic metals,
thus causing difficulties in recycle and disposal.
Steel produced from iron and scrap metal is converted to a useable form
by primary rolling, or continuous casting. If primary rolling is to be done
the metal is cast into large ingots about 60 to 80 centimeters square and
weighing 10 to 50 tonnes. The ingots are removed from their molds when they
are solid but still hot and then placed into a soaking pit, a top opening type
furnace. The bottom of this pit is covered with a layer of coke breeze before
the ingot is put in. The steel ingot remains in this soaking pit until it is
homogeneous in temperature. Then it is removed and sent to primary rolling.
Soaking pit slag is formed by metal oxides that flake off the ingot and fuse
with the coke breeze. It is removed periodically and landfilled. This slag
is not comparable with ironmaking or steelmaking slag in that it is composed
of metal oxides and carbon.
Primary rolling converts the hot steel ingot into a form that can be
further processed: into slabs 60 to 150 centimeters wide and 5 to 23 centi-
meters thick; billets (5 by 5 to 13 by 13 centimeters); or blooms (15 by 15
to 30 by 30 centimeters). Bars can also be produced and the metal can be sent
directly to rolling mills for producing structural shapes. During primary
rolling, high pressure water sprays remove the oxide film that continuously
11
-------
forms on the red hot metal and also cool the rollers. These sprays produce
waste scale and sludge. The scale consists of large pieces of iron oxide that
have sloughed off the ingot. These are usually returned to the blast furnace
as raw material. Sludge consists of very fine pieces of iron oxide dispersed
in the water used for cooling and cleaning the metal.
In the primary rolling process the ends of the slabs or billets are
metallurgically defective and are cut off. This amounts to eight or more
percent of the metal becoming scrap. The final product of primary rolling is
usually cooled and stockpiled for further processing according to facilities
and market needs.
Continuous casting is the alternative method of producing shapes from
liquid steel. This method is becoming popular because it produces a higher
yield of steel product than with primary rolling, about 94 percent compared to
81 percent. As a result, the waste stream is accordingly smaller. In con-
tinuous casting, the molten steel is poured into a small ladle or tundish. A
continuously controlled valve in the bottom of the tundish pours the metal
into a water-cooled mold—usually made of copper. The metal solidifies along
the surfaces of this mold and slides out of it through a system of guide
rollers where it is further cooled with water sprays thereby producing either
a billet or a slab. After solidification, the metal is cut into lengths by
traveling torches, and sent to cooling racks to cool to room temperature. The
waste stream output from this process consists of scrap and scale, since the
metal always continues to oxidize to iron oxide while hot. This scale is
smaller than that from primary rolling and usually ends up in a sludge with
the cooling water.
Nearly 90 percent of the shapes produced by primary rolling or continuous
casting are processed further by hot rolling. The stored slabs or billets are
transferred to the hot rolling mill where the first operation is to reheat
them in a furnace to a temperature that allows flexibility for shaping. After
reaching a suitable temperature, around 1200°C, the steel is transferred to
the rolling mills and further squeezed to the desired shape and dimension.
Since the metal is hot and continuously oxidizes, the process of scale removal
with high pressure water streams is again employed. The result is a waste
stream of scale and sludge as in the case of primary rolling. The sludge
12
-------
produced is often contaminated with oil from the pressurized lubrication
system on the bearings of the rollers. Trimming and cutting also produce
scrap in this operation. About 50 percent of the output from the hot rolling
mill is in a form desired by some customers and is sold at this point. The
remainder proceeds to a cold rolling operation.
The hot rolled steel has a black to gray-black coating of iron oxide on
its surface. Before cold rolling can be pursued, this oxide coating must be
removed. This is done by a process called pickling in which the metal is
dipped into sulfuric or hydrochloric acid. For example, coils of 0.3 to 0.6
centimeter thick steel sheet, weighing about 30 tonnes, are unrolled and
welded into a continuous strip which passes through the pickle tanks. The
metal travels about 122 meters (400 feet) in a vat of acid at about 6 meters
per second (1100 feet per minute) if hydrochloric acid is used, or about half
that speed if sulfuric acid is used. At the end of the pickle line, the metal
is rerolled into coils which are then sent on to the cold rolling mill. The
pickling operation produces waste acid, referred to as spent pickle liquor,
which has 10 to 25 percent iron in the solution. This is a problematical
waste stream as it produces a large quantity of gelatinous sludge if it is
neutralized. A large pickling line may produce as much as 500 liters (130
gallons) of spent acid per minute, 24 hours a day.
Cold rolling accomplishes three things. First, the metal is reduced to
the thickness desired by the customer; second, the metal acquires a smooth
desirable surface finish and third, the cold metal is hardened by a metal-
lurgical transformation. The rolling operation generates heat requiring that
the rollers and the metal be cooled with water. In this case, plain water
cannot be used but rather an emulsion of oil and water is required. The
cooling water must be processed to remove tramp oil and also some sludge. The
quantity of the sludge produced is a very small fraction, less than one percent
of that produced by hot rolling. After the cold rolling process, the product
usually goes directly to the customer unless it is to be given further
finishing with zinc, tin, or other coatings.
13
-------
5.2 INDUSTRY OVERVIEW
5.2.1 Number of Plants
By updating information contained in the 1977 Directory of Iron and
Steel Works,3 the EPA Effluent Guidelines 1977 Industry Survey,4 and by
drawing upon other information on sinter plants, estimates of the numbers of
operating plants in the U.S. in 1977 were obtained. There were 169 operating
plants making either iron or steel or both. There were 153 plants making
steel using either hot metal and scrap steel or just scrap steel. There were
28 integrated plants that is, plants making coke, sinter, iron and steel, and
operating rolling mills. There are 19 major and 72 smaller firms (91 total)
engaged in iron and steelmaking.
Table 1 provides estimates of the number of plants at which each of the
basic operations (coking, sintering, blast furnace ironmaking, and steelmaking)
are conducted together with the estimated total annual capacity. This Table
also shows that 50 plants were using continuous casting in 1977.
TABLE 1. CAPACITY ESTIMATES BY PROCESS
Process
Coke
Sinter
Blast Furnace (BF)
Basic Oxygen Furnace (BOF)
Open Hearth Furnace (OH)
Electric Arc Furnace (EAF)
Continuous Casting
No. of
Plants
46
35
57
35
19
120
50
Estimated Capacity
(megatonnes/yr)
58.4
50.2
95.0
88.3
22.9
31.8
21.3
5.2.2 Size and Capacity Distribution
Statistical investigation of the plant size and capacity distributions
shows that the industry is divided into two distinctly different processing
types: relatively small plants with EAF's and large complexes with BOF's, and
14
-------
some open hearths. For this reason, separate distributions have been developed
for those two types and are shown in Figure 3 for use in determining either
the percent of total plants or the percent of total capacity less than the
indicated size. The frequency distributions shown are log-normal.
Figure 4 shows, by Corporation, the size distribution of the plants that
account for approximately 90 percent of national capacity. Capacity accounted
for by the integrated steel companies is shown in Figure 5, along with that of
plants with only EAF's. The latter collectively provide a significant portion
of national capacity and industry solid wastes.
Raw steel capacity by EPA region is shown in Figure 6.
In Summary: Two large corporations, U.S. Steel and Bethlehem account for
35.6 percent of national capacity; five medium-sized corporations (LTV, Re-
public, National, Armco, and Inland) account for 36 percent; small corporations
and minipi ants account for 28 percent.
5.2.3 Geographic Location of Plants
Figure 7 geographically displays U.S. steelmaking facilities with the
number of plants in each state identified. Black areas represent locations of
major steel plants. The close-dot shading of Pennsylvania, Ohio, and Indiana
indicates that these states account for 54 percent of the total capacity;
horizontal shading, that Illinois and Michigan account for 18 percent. Wide-
dots identify Alabama, California, Colorado, Kentucky, New York, Texas, Utah,
and West Virginia as accounting for 24 percent. Unshaded states collectively
represent less than 5 percent.
5.3 GENERAL ECONOMIC STATUS OF THE INDUSTRY
The general economic status of the iron and steel industry is an important
factor to be considered in implementing adequate control and resource recovery
practices. The industry's cash flow, used for capital expenditures, dividends,
and debt reduction, has declined relative to other industries since 1974, and
in 1976, measured only 132 percent of its 1967 value (Figure 8). In contrast,
the Standard and Poor's 400 Industries collectively measured 200 percent of
their 1967 value, and the paper industry measured 218 percent of its 1967
value. Cash flow is defined as net earnings plus depreciation and amorti-
zation.
15
-------
•g
10,000
5.000 3,000 2.000
1.000 500 300 200
Sze of Plant (1,000 ton)
100
Figure 3. Size and capacity cumulative distributions for two types
of steel plants.
16
-------
25 r-
20.
15-
u
<
LL
a
10-
5 -
•
-
_
-
^
j
-------
cc
111
a.
1
CO
'TYPICAL 2.5 MEGATONNE
PLANT"
o
Tl
m
rn
- 5
USS BETH. LTV- REP. NAT'L ARMCO IN- WHEEL- Kaiser
LYKES LAND Pitts.
Lone CF&I Inter- EN- Electric
Star Lake VIRO Arc
DYNE Only
INTEGRATED STEEL COMPANIES
Figure 5. Raw steel capacity of Integrated companies.
-------
<£>
90
70
60
50
30
20
TON
NEW VCHK
'PHILADELPHIA
^^ VTA VTA
-,60
GO
4567
EPA REGION
Figure 6. Raw steel capacity by EPA Region.
40
30
O
I
20
10
V STf
10
-------
". , •• ,*'
— - .*,*> -"•••
20 to 30 Mcgatonnas/yr
10 to 20 Mcgatonnes/yr
1 to 10 Megatonncs/yr
Figure 7. Distribution of iron and steelmaking facilities.
-------
220
200
180
5 160
B
^
-------
The reduction of the profit margins may be approximated by focusing on the
decline of gross income—defined as revenue minus operating costs—before the
deduction of depreciation, interest, and income tax.
Table 2 shows gross income expressed as a percent of sales and illustrates
the decline in this gross return over the past 20 years. Clearly, the trend of
declining in profit margins predates pollution control expenses.
TABLE 2. GROSS INCOME8'9
Years
1955-59
1960-64
1965-69
1970-74
1975-77
Gross Income
cent of Sales
19.0
16.6
15.4
12.3
9.7
as a Per-
(avg.)
Imported steel has decreased the share of the U.S. market for the domestic
steel industry and, at the same time, has restricted price increases. Imports
are expected to fall off in 1978 as the trigger pricing mechanism takes
effect.10
Table 3 presents the quantity of imported steel, as a percentage of
domestic production, for the period 1973-1978.
TABLE 3. IMPORTS: % OF DOMESTIC CONSUMPTION10
Year 1973 1974 1975 1976 1977 1978 EST.
% 12.4 13.4 13.4 14.1 17.8 14.5
Predictions for the near term, from Standard and Poors' Industry Surveys,
are for a profit gain in 1978, but the improvements are expected to fall short
of what is considered to be required for modernization, expansion, and divi-
dends. A further improvement is expected through 1979 if the economy does not
slip into a recession and steel imports do not rebound.
22
-------
A summary of the financial statements of companies representing approxi-
mately 90 percent of the raw steel production is provided in Table 4 and
underscores the recent profit squeeze faced by the steel industry.
TABLE 4. SUMMARY OF FINANCIAL STATEMENTS* (ALL DOLLARS IN MILLIONS)9
REVENUE
Employment Costs
Materials, Supplies, etc.
Depreciation, amortization
Interest on long term debt
Taxes other than income
Income taxes
(Gain) loss on discon-
tinued operations, sales
of assets
TOTAL COSTS
Net Income
% of Revenue
Current Assets $
Current Liabilities
Total Assets
Total Liabilities
Equity
Current Assets/Current
Liabilities
Li abilities/ Equity
CAPITAL EXPENDITURES
1977
39,787.4
14,418.6
22,129.0
1,528.5
594.3
597.1
(452.4)
949.1
39,764.2
23.2**
0.06
12,356.6
6,800.6
35,413.7
17,776.3
17,637.4
1.82
1.01
2,857.6
1976
36,462.4
13,273.6
19,175.7
1,378.4
480.7
560.8
265.7
(9.9)
35,125.0
1,337.4
3.7
11,828.6
6,114.5
33,564.0
15,536.7
18,027.3
1.70
0.86
3,252.9
1975
33,676.3
11. 883.1
17,373.6
1,272.8
382.5
515.7
653.7
32,081.4
1,594.9
4.7
10,750.4
5,311.2
30,419.9
13,227.7
17,192.2
1.88
0.77
3,179.4
1974
38,243.6
11,858.5
19,900.3
1,327.2
353.7
482.6
1,846.1
35,768.4
2,475.2
6.5
12,212.5
6,729.5
29,506.4
13,263.2
16,243.2
1.81
0.82
2,114.7
1973
28,863.2
10,201.3
14,450.5
1,262.6-
357.4
452.5
866.7
27,591.0
1,272.2
4.4
9,512.2
4,965.0
26,132.7
11,619.2
14,513.5
1.92
0.80
1,399.9
*Companies representing 90 percent of raw steel production.
**Reflects substantial impact of permanent plant closings.
23
-------
5.3.1 Capital Expenditures By The Steel Industry
Capital expenditures for replacement and modernization, modest capacity
increase, and pollution abatement will approximate $3 billion per year through
8 n
1980. An AlSI-funded study by the A. D. Little Company estimates a capital
cost of $24 billion for 1978-1985 to replace 40 million tonnes of raw steel
capability based on a historical replacement rate of 3.5 percent. However,
this report adds to the $24 billion estimate the cost of environmental control
requirements for air and water, which increases the 8 year total to $28.9
billion with no growth in capacity. Based on the results of 1973-1977, cash
flow from net profits and depreciation would be $26.4 billion so that, with no
growth, the industry would fall short of capital, via internal generation, by
about $2.5 billion.11
5.3.2 Status of the Six Largest Integrated Steel Producers
The six corporations with the greatest raw steel capacity are listed in
this section as U.S. Steel, Bethlehem, National, Republic, Armco, and Inland.
These companies accounted for nearly two-thirds of 1977 raw steel production.
Table 5 is a comparative financial summary of the six corporations.
These data are used in compiling Table 6, which provides financial ratios for
the six companies, for all reporting companies, and for the whole industry
(from Dun's review) for comparison.
However, with the recently approved merger of Lykes-Youngstown with LTV
Corporation (Jones and Laughlin Steel), the resulting corporation has a raw
steel capacity that ranks third nationally. Financial information on this new
corporation is not included due to a lack of comparative data.
Brief descriptions of company employment and capital spending projects
follows.
U.S. Steel
U.S. Steel produces steel at 13 locations with a total corporate employ-
ment of 165,845 in 1977. The company is engaged in extensive planning for a
new location in northwestern Ohio with a capacity of 2.73 million net tonnes
per year. The investment cost is estimated at $1,430 per annual tonne
24
-------
TABLE 5. FINANCIAL SUMMARY OF SIX INTEGRATED STEEL COMPANIES5'12
(all dollars in millions)
Net Sales
Operating Margin3
Net Income
Capital Expenditure
Total Assets
Current Assets
Current Liabilities
Total Liabilities
Short Term Debt
Long Term Debt
Total Debt
Net Worth (Equity)
Invested Capital
Year
77
76
77
76
77
76
77
76
77
76
77
76
77
76
77
76
77
76
77
76
77
76
77
76
77
76
USS
9609.9
8607.8
1665.4
1887.7
137.9
410.0
864.7
957.3
9914.4
9167.9
3040.3
2791.2
1712.5
1637.4
4772.7
4038.9
250.0
195.3
2550.2
1959.9
2800.2
2155.2
5141.7
5129.0
7941.9
7284.2
Bethlehem
5370
5248
506.8
762.1
(18.7)
168
551.9
406.6
4898.9
4977.5
1495.7
1615.2
978.5
822.5
2720.0
2284.9
3.3
12.9
1154.8
1023.1
1158.1
1036.0
2178.9
2692.6
3337.0
3728.6
National
3138.9
2840.5
347.9
343.0
60.1
85.7
161.7
270.9
2827.6
2798.0
989.2
995.5
554.6
574.8
1546.6
1534.9
19.3
21.8
722.3
743.8
741.6
765.6
1281.0
1263.1
2022.6
2028.7
Republic
2909.4
2545.6
427.3
390.6
41.0
65.9
155.5
248.7
2406.3
2333.1
834.7
788.2
384.4
434.4
1072.3
1014.2
17.8
13.9
452.3
372.2
470.1
386.1
1334.0
1318.9
1804.1
1705.0
ARMCO
3549.2
3151.0
415.7
390.7
119.8
123.7
146.4
272.0
2882.8
2833.6
1053.8
1039.9
577.3
509.5
1419.8
1427.5
110.3
139.2
643.0
667.2
753.3
806.4
1463.0
1406.1
2216.3
2212.5
Inland
2681.6
2388.2
391.9
431.9
87.8
104.0
282.0
303.8
2302.4
2070.1
691.4
627.9
364.7
324.5
1155.7
965.5
13.2
11.0
614.0
480.5
627.2
491.5
1146.7
1104.7
1773.9
1596.2
aRevenue from sales minus manufacturing expense
bNet worth plus total debt
25
-------
TABLE 6. COMPARISON OF FINANCIAL RATIOS5'12
N>
USS Bethlehem National Republic ARMCQ Inland 90% of Industry8 Dun's Review (Dec. 1977)b
Current Assets
Current Debts
1977
1976
1.78
1.70
1.53
1.96
1.78
1.73
2.17
1.81
1.83
2.04
1.90
2.13
1.82
1.70
(3.01)
2.25
(1.80)
Net Profits
Net Sales
Net Prof its
Net Worth
Liabilities
Net Worth
X 100
X 100
1977
1976
1977
1976
1977
1976
1.4
4.8
2.7
8.0
0.93
0:79
Operating Profit 1977 743.9
(millions of dollars) 1976 1030.2
Capital Expenditures 1977 864.7
(millions of dollars) 1976 957.3
Planned Capital
Expenditures
(millions of dollars)
1978 NA
(0.3)c
3.2
(0.9)
6.2
1.25
0.85
294.5
561.4
551.9
406.6
500
1.9
3.0
4.7
6.8
1.21
1.22
319.7
327.5
161.7
270.9
NA°
1.4
2.6
3.1
5.0
0.80
0.77
245.8
217.8
155.5
248.7
225
3.4
3.9
8.2
8.8
0.97
1.02
325.2
294.3
146.4
272.0
3.3
4.4
7.7
9.4
1.01
0.87
256.4
300.7
282.0
303.8
2.4C
3.7
5.5C
7.4
1.01
0.86
121.0 290
(5.7) 4.1 (2.2)
(15.1) 9.1 (6.2)
(0.60) 0.83 (1.25)
a Represents companies with 90% of raw steel production^
b Represents 52 companies of blast furnaces, steel works, and rolling mills; the middle number represents the median, and the numbers in parenthesis
represent the upper and lower quartile.
^Excluding pretax losses from plant closings
dNA= Not Available
-------
(including raw materials, transportation, and support facilities). The
company reportedly awaits a cost-price relationship suitable to justify the
investment.
Recently completed projects include installation of two EAFs, two slab
casters, a plate mill, rehabilitation of five coke oven batteries, blast fur-
nace enlargement at Braddock, PA, a new pipe mill, and an electrogalvanizing
facility. Planned projects include a 182 tonne Q-BOP and a 4,545 tonne per
day blast furnace at Fairfield, Alabama, air and water quality control facilities,
taconite expansion, hot strip mill, coke oven gas processing facility, a new
coke oven battery, rehabilitation of two more coke batteries, and boiler
l ?
emission control facilities.
TABLE 7. UNITED STATES STEEL ($MM)7'12'13
1st Quarter
1978 1977 1976 1975 1974
Sales
Operating Profit
% of Sales
Pretax Profit (Loss)
% of Sales
Net Income (Loss)
% of Sales
Capital Expenditures
Raw Steel (million
tonnes)
% of Industry
2,427.9
68.9
2.8
( 91.7)
( 3.8)
( 58.7)
( 2.4)
— -
—
• «•
9,610
743.9
1.1
101.8
1.1
137.9
1.4
864.7
26.2
23.1
8,608
1,030.2
12.0
518.3
6.0
410.3
4.8
957.0
25.7
22.1
8,171
1,170.8
14.3
823.6
10.1
559.7
6.9
787.4
24.0
22.6
9,140
1,537.4
16.7
1,033.3
11.2
630.4
6.9
508.3
30.8
23.3
Bethlehem Steel
Bethlehem operates eight steel producing plants. A partial shutdown was
announced at the end of 1977 due to a reduction in capacity at the Lackawanna,
N.Y. plant from 4.4 to 2.5 million tonnes per year, and at the Johnstown, Pa.
plant from 1.6 to 1.1 million tonnes per year, resulting in a reduction of
employment to 93,000 persons. Competition from imports, flood damage (Johns-
town), and marginal operations where investment to modernize and add pollution
control equipment could not be justified were cited as reasons for the shut-
downs .
27
-------
Projects include a new basic oxygen furnace at Burns Harbor, a blast
furnace at Sparrows Point, a scrap melter at Lackawanna, a novel coke quench
car, two water treatment plants, a new bar mill, and a new plate mill.
12
capital expenditures were cut by $128 million in 1977.
TABLE 8. BETHLEHEM STEEL ($MM)7'12'13
Planned
1
Sales
Operating Profit
% of Sales
Pretax Profit (Loss)
% of Sales
Net Income (Loss)
% of Sales
Capital Expenditures
Raw Steel (million
tonnes)
% of Industry
st Quarter
1978
1,380.9
97.7
7.0
1.1
0.0
1.1
0.0
—
—
---
1977*
5,370.0
294.5
5.5
(120.3)
( 2.2)
( 18.7)
( 0.3)
551.9
15.1
13.3
1976
5,248.0
561.4
10.7
194.0
3.7
168.0
3.2
406.6
17.2
14.7
1975
4,977.2
597.6
12.0
283.0
5.4
242.0
4.9
674.3
15.9
15.0
1974
5,381.0
866.3
16.4
616.1
11.4
342.0
6.4
524.2
20.3
15.3
*Before nonrecurring writeoff of $791 million before taxes.
National Steel
National Steel has three basic steel producing plants with approximately
36,000 employees. Projects underway include a water quality control system,
coke battery improvements, and blast furnace rebuilding at the Weirton, W.Va.
plant, a continuous slab caster at the Great Lakes Division, a wastewater
treatment plant, a novel coke pushing emission control system, and new coke
12
oven facilities at Granite City.
Republic Steel
Republic Steel has six steelmaking plants with a total corporate employ-
ment of 41,000. Two bottom blown basic oxygen furnaces (Q-BOP) were recently
installed at the Chicago plant and marked the end of open hearth steel pro-
duction for Republic. Other projects include a continuous silicon annealing
line, 10 high speed grinders with air pollution controls to eliminate scarfing
at the Canton, Ohio plant, and a suppressed combustion air cleaning system for
12
the basic oxygen furnaces at Cleveland.
28
-------
TABLE 9. NATIONAL STEEL f$MN07'12'13
1st Quarter
1978 1977
1976
1975
TABLE 10. REPUBLIC STEEL ($MM)7'12'13
1974
Sales
Operating Profit
% of Sales
Pretax Profit
% of Sales
Net Income
% of Sales
Capital Expenditures
Raw Steel (million tonnes)
% of Industry
846
50.4
6.0
1.6
0.0
2.4
0.2
_._
—
___
3,138.9
319.7
10.1
68.2
2.2
60.1
1.9
161.7
8.5
7.5
2,840.5
327.5
11.5
95.0
3.3
85.7
3.0
270.9
9.8
8.4
2,241.2
174.6
7.8
63.6
2.8
58.1
2.6
313.3
7.8
7.4
2,727.8
427.4
15.7
334.4
12.3
175.8
6.4
182.0
9.6
7.3
1978
1977
1976
1975
1974
Sales
Operating Profit
% of Sales
Pretax Profit
% of Sales
Net Income
% of Sales
Capital Expenditures
Raw Steel (million
tonnes)
% of Industry
831.2
61.9
7.4
31.8
3.8
9.8
1.2
—
—
---
2,904.4
245.8
8.4
41.6
1.4
41.0
1.4
155.5
8.4
7.4
2,545.6
217.8
8.6
41.0
1.6
65.9
2.6
248.7
8.7
7.5
2,333.3
251.1
10.8
91.4
3.9
72.2
3.1
200.0
8.0
7.5
2,741.4
438.7
16.0
298.6
10.9
170.7
6.2
102.5
9.6
7.3
Armco Incorporated
Armco has eight steel producing plants with 33,000 employees. In 1977,
steel accounted for 68 percent of corporate sales and 41 percent of the
operating profits. Net income as percent of sales has ranged from 3.4 to 3.9
percent for 1975-1977, down from 6.4 percent in 1974.
Recently completed capital projects include melting, casting, and billet
facilities at Kansas City, Mo., argon oxygen reactor at Butler, Pa., and a
coal mine and processing plant in West Virginia. Appropriations have been
29
-------
approved for hot metal desulfurization at Ashland, Ky., a fine coal cleaning
circuit at Big Mountain Coal, Inc., and expansion of Union Wire Rope facili-
ties. Capital expenditures have been used with emphasis on modernization
12
instead of expansion.
TABLE 11. ARMCQ. INC. ($MM)7>12>13
1st Quarter
1978
1977
1976
1975
1974
Consolidated:
Sales
Operating Profit
% of Sales
Pretax Profit
% of Sales
Net Income
% of Sales
Capital Expenditures
Steel Alone:
Sales
Operating Profit
% of Sales
Net Income
% of Sales
Capital Expenditures
Raw Steel (million tonnes)
% of Industry
946.2
86.1
9.1
45.3
4.8
30.2
3.2
—
3,549.2
325.2
9.2
121.1
3.4
119.8
3.4
146.4
~
3,399.4
176.5
7.3
86.3
3.6
98.1
7.2
6.2
3,151.0
294.3
9.3
116.0
3.7
123.7
3.9
272.0
2,093.8
150.3
7.2
51.2
2.4
236.1
6.8
5.8
3,046.8
368.3
12.1
172.1
5.6
116.7
3.8
255.5
1,956.6
170.0
8.7
12.0
0.6
212.5
6.4
6.0
3,190.1
512.6
16.1
351.7
11.0
203.6
6.4
104.6
2,202.4
396.1
18.0
112.7
5.1
81.3
8.1
6.1
Inland Steel
Inland Steel's only producing plant is their Indiana Harbor Works in East
Chicago, Indiana. Total employment at Inland is 35,200. 79 percent of the
company's steel is shipped to the surrounding five state areas—Illinois,
Indiana, Ohio, Michigan, and Wisconsin.
Inland is presently in the middle of a $2 billion expansion program
started in 1974 and continuing through the mid !980's that is designed to
increase raw steelmaking capacity by 2.3 million annual tonnes. The first
phase of $800 million expenditure is scheduled for completion in 1979 and
30
-------
includes a new blast furnace, coke oven battery, boiler-blower house, environ-
mental controls, and raw materials facilities. This will result in a 1.0
million tonne increase in capacity. The second phase of $1.2 billion will
include a plate mill, improvement to the hot strip mill and EOF, a coke oven
battery, and slab casting machine. A 1.3 million tonne increase in capacity
12
is expected from the second phase.
TABLE 12. INLAND STEEL (SMM)7'12'13
1st Quarter
1978 1977 1976 1975 1974
Sales
Operating Profit
% of Sales
Pretax Profit
% of Sales
Net Income
% of Sales
Capital Expenditures
Raw Steel (million
tonnes)
% of Industry
756.5
61.2
8.1
28.6
3.8
24.2
3.2
___
___
— __
2,681.6
256.4
9.6
93.1
3.5
87.8
3.3
282.0
7.8
6.2
2,388.2
270.9
11.3
155.6
6.5
104.0
4.4
303.8
7.9
6.2
2,107.4
245.1
11.6
126.9
6.0
83.3
4.0
222.5
7.3
6.2
2,450.3
376.5
15.4
273.0
11.1
148.0
6.0
101.4
8.0
5.5
Pollution Control Expenditures
Table 13 gives a comparison of the amount expended by the six integrated
steel companies for pollution control.
31
-------
ro
TABLE 13. POLLUTION CONTROL EXPENDITURES12
(all dollars in millions)
Pollution Control Expenditures, 1973-1977 $
Pollution Control Expenditures, est. 1978 $
Total Capital Expenditure, est. 1978 $
Raw Steel Produced, 1977 (millions tonnes)
% of Domestic Steel Production, 1977
uss
410
196
LT.870d
26.2
23.1
Bethlehem
322
85
500
15.1
13.3
National
NA8
53°
NA
8.5
7.5
Republic
NAb
45
225
8.4
7.4
ARMCO
168
16
121
7.2
6.2
Inland
153
44
290
7.1
6.2
aNA = not available
b$330 million in place 1977
cTotal of $105 million estimated 1978 and 1979
"LT. less than ($870 million is previous 5 yr. average)
-------
6.0 WASTE CHARACTERIZATION
This study is primarily concerned with the waste materials produced by
the iron and steel industry which are not likely to be hazardous subject to
regulation under Subtitle C of RCRA. All wastes are identified, however,
including those now proposed by EPA as hazardous (Subtitle C, Sec. 3001). The
term "solid waste" means any garbage, refuse, sludge from a waste treatment
plant, water supply treatment, or air pollution control facility and other
discarded material, including solid, liquid, semi-solid, or contained gaseous
materials resulting from industrial activities, but does not include industrial
discharges which are point sources subject to permit under the Federal Water
Pollution Control Act (FWPC) Section 402, as amended. Solid wastes in this
industry include slag, scrap, sludge, scale, and dust. This section charac-
terizes them in four categories: coke plant wastes, iron oxide wastes, slag,
and scrap. Waste production can be related to steel production through emis-
sion factors. Flow sheets are provided to identify the source of each waste
relation to the processing operations. Wastes to air, land, and water are
considered.
Waste production by state, region, and nation is given together with
information on its eventual disposition.
The EPA Office of Solid Waste has proposed (40 CFR 250, 12/18/78) that
certain iron and steel wastes be listed as hazardous. A discussion of the
potential hazard from these wastes is reported by Enviro Control, Inc.
Although data are presented in this report which may be relevant to the
classification of hazardous wastes, the designation of wastes for inclusion
in the listings is not within the scope of this investigation. Therefore, the
costs, requirements, and impact of hazardous waste disposal are not considered
in this investigation. All industry waste streams not listed in the 12/18/78
proposal are considered subject to Section 4004 RCRA requirements.
33
-------
Representative Iron and Steel Plant
Figure 9 shows the product movement in a "typical" 2.5 megatonne inte-
grated iron and steel .plant. The diagram shows tonnages for the various
intermediate products as well as the final delivered output. It assumes that
all steel is made by the BOF and EAF. The OH is omitted from this considera-
tion because it is a declining technology.
It should be recognized, however, that the elimination of the OH from the
diagram is an arbitrary constraint which is imposed on the typical plant. It
is expected that certain of the open hearths in the United States are of
relatively modern vintage, are equipped with environmental controls, and
operate with a substantial degree of efficiency. The production of OH wastes
on a state and nationwide basis is included in the solid waste listings.
Each of the individual processes, i.e, the coke oven, the blast furnace,
etc. are diagramed in greater detail in subsequent process diagrams. These
process diagrams are not formal material balances. They are presented to
illustrate quantities of waste arising from the given throughput and are based
on generation factors that may vary significantly from plant to plant. The
number of significant figures used does not imply an obtainable accuracy; they
are given merely as a convenience to allow closure within these installations.
The diagrams show intermedia transfers of materials and are keyed to tables
which show tentative materials produced and indicate the influence of compli-
ance with present and future air and water pollution control regulations.
As will be noted in greater detail in Section 6.3, the total quantity of solid
waste generated in the iron and steel industry will be relatively unaffected
by compliance with anticipated air and water regulations.
The first step in characterization was to identify those wastes that pre-
sent difficult problems for disposal. For example, coke breeze is relatively
low in volume and is essentially completely recycled or reused at the present
time. Coke by-product wastes are low volume but some are hazardous. Scrap,
although high in tonnage, is also recycled or reused. Blast furnace slag is
90 percent recycled or reused, whereas only an estimated 45 percent of steel-
making slag is recycled. Of the iron oxide materials, the amounts which are
landfilled or stockpiled are 39 percent of the dusts, 43 percent of the scales
34
-------
2610 -«
Organic Sludga
1.268.300 Coal
I
Coke
32,000 Bre«ze -*
1.970,000 Ore
and Pellets
40,000-*
Sludge
i
210.000 Coke
Oven Gas
Sinter
10,000 Coke
691.000 Sinter
Blast
Furnace
I
t
557.000
Slag
41.000-*-
Sludge
1.600,000 Iran
521.000
Scrap
Basic
Oxygen
Furnace
*
290,000
Slag
Electric
Arc
Furnace
.. 2,000.000 Steel
60.000 Slag
80 Sludge-*
2.500 Sludge "*
,, 500,000 Steri
2,500.000 Steel
Continuous Casting
Primary Rolling
240,000 Sales -*—
3,100 Sludge-*—'•
1,098,000 Sales -*•
-*- 43.000 Scrap"
2,140.000 Steel
223.450 Scrap
V 1.900.000 Steel
Hot Rolling
140.000 (Wet)-
Sludge
110 Sludge -*-
•*- 62.350 Scrap
1.801,200 Steel
v 703.200 Steel
Pickling
Cold Rolling
475.000 Sales -*•
1.400 Sludge-*-
530 Sludge -<-
700.000 Steel
Caivanizing
Tin Plating
•*• 14,500 Oust
-*- 25,400 Dust
-»• 6,500 Dust
-». 6,900 Sole
-*- 60.600 Scale
-*» 23.400 Soaking Pit
Scale
->- 32,900 Scale
-*- 40 Scale
-*-125.000 Galvanized Product
•*• 100,000 Tin Plated Product
Figure 9. Waste production frojn typical plant with 2,500,000 tonnes of stesl per year (all numbers in tonnes).
35
-------
(which include soaking pit scales), and 53 percent of the sludges. These
numbers present some indications of where the solid waste disposal problems
lie.
The fact that a substantial portion of steelmaking slag is not used in a
productive manner is not as serious a loss of resources as with respect to
iron oxide waste. The steelmaking slag may have, in many cases, substantially
little intrinsic value. The iron oxide waste, however, represents a loss of
metallic value, not only of iron, but also of zinc, tin, and other metallies.
The presence of zinc and tin in the iron oxide waste is of particular
significance. Their presence in any substantial amount makes the waste un-
acceptable for conventional recycling to sintering and eventual return to the
blast furnace. On the other hand, if they could be removed and recovered as a
separate metallic component, then the iron oxide could be recycled. The
problem of recovering these metals lies essentially in the realm of economics
and plant size. For economical removal of these metals from the iron oxide
and subsequent reprocessing of the iron oxide into a form suitable for
recycle, the process plant must handle larger amounts of wastes than are
produced in the largest steel plant currently in operation. This leads to the
consideration of regional treatment for processing iron oxide waste in certain
selected areas of the United States.
Additional information on all of these considerations is provided in the
following subsections.
6.1 ANALYSIS OF PROCESSES THAT GENERATE WASTE
This section contains descriptions of the individual processes which
appeared on the flow sheet in Figure 9. Estimates are provided for material
flow of the various products and of the waste material that is produced.
Where applicable, intermedia transfers of solid waste material are shown.
Solid wastes are shown in larger print on the individual diagrams since they
are of primary concern.
An integrated steel mill performs all the operations needed to convert
the raw materials (iron ore, coal and flux material) into finished products.
Principal operations consist of coking, sintering, blast furnace ironmaking,
36
-------
steelmaking via the BOF or EAF, continuous casting, hot and cold rolling, and
various finishing operations. The major operations are described in the
following sections.
6.1.1 By-Product Coking
Figure 10 shows a block diagram for a typical coking operation. Of
particular interest in this study is the coal charged to the coke oven, the
coke which is produced, and the breeze which is a solid waste.
The by-product coke oven heats coal in the absence of air to distill off
the volatile matter and to leave coke as a solid residue. The hot coke is
quenched with water and then diverted to the blast furnace where it acts as
the fuel and reducing agent in the ironmaking process. During the coke
quenching and handling operations, a solid coke waste (breeze) is produced.
The gas which leaves the oven is diverted via a gas main to the by-
product plant where it is cooled, thereby condensing waste liquors and tar
products. Subsequent processing separates light oils which are invariably
sold as by-products and ammonia which may be sold as anhydrous ammonia or
ammonium sulfate. In view of current regulations regarding sulfur, it is
usually removed either as elemental sulfur or sulfuric acid.
The processing of waste liquor customarily involves the use of distil-
lation followed by biological oxidation. If lime is used in the distillation
process a lime sludge is formed; however, the use of sodium hydroxide avoids
the generation of this waste. The biological oxidation process normally pro-
duces a biological sludge.
Recent emphasis on the control of emissions to the atmosphere from the
coking process has been directed toward the charging operation, the leakage
from doors, and coke pushing. The control systems for charging and door
leakage can be arranged so as to direct emissions back into the oven and,
therefore, do not produce a solid waste as such. The pushing emissions con-
trol, in contrast, captures the emissions in a control device and produces a
solid waste. This waste, which is mostly fine carbon particles, is small in
quantity, approximately 0.5 kg per tonne (one pound per ton) of coke produced.
The only coke plant waste which may, with some confidence, be classed as
nonhazardous is coke breeze. All other coke plant wastes contain either oil,
37
-------
Gi
00
5,700 Uncontrolled Particulate
Emissions
1,268,343 Coal
Coke
Oven
32,000 Breeze
(recycled, sold)
900,000 Coke
(to Qlast Furnace)
210,000 Coke Oven Gas (to coki oven underfilling, sinter plant, etc.)
Oleum Wash Waste,
Neutralization
Waste*
By-Product
Plant
540 Still Lime Sludge
(landfillcd)
540 Tar Tank Sludge
(landfillcd)
Biological
Treatment
Plant
'Quantity unknown, from light oil refining operation.
1530 Sludge
(landfilled)
72,100 Products
(Tar, Sulfate, Light Oil)
45,900 Water from Coke Oven
». Final Effluent
33 Solids
Figure 10. Material flow for coke plant In production of 2,500,000 tonnes of steel per year (all numbers in tonnes).
1
-------
tar, or other toxic compounds which could be classed as hazardous. In a
typical integrated steel plant, all of the coke breeze is recycled or used.
In summary, the coke plant produces both potentially hazardous and non-
hazardous wastes. Currently, the nonhazardous wastes are typically recycled
or reused, leaving the hazardous wastes as a disposal or stockpiling problem.
6.1.2 Sintering
Figure 11 shows a material flow sheet for the sintering plant with the
various charge materials indicated. Some of the sinter is used to form a
hearth-layer which protects the sintering grates. The windbox exhaust is
indicated as passing through a cyclone and electrostatic precipitator (ESP).
Alternative control devices are scrubbers and baghouses. The discharge-end
emissions are generally controlled by means of a baghouse.
The purpose of the sintering process is to agglomerate fine oxide ma-
terials into lumps necessary for charging into the blast furnace. These
materials include fine ores, various recycled fine oxide waste materials from
iron- and steelmaking operations, fuel (often in the form of coke breeze), and
limestone for fluxing purposes. In the sintering process, the material is
mixed, placed on a slowly moving grate and ignited. A downflow of air through
the bed into the windbox below consumes the carbon, thereby maintaining igni-
tion and fusing the fine materials into sinter lumps. The lumps are crushed,
cooled, screened, and delivered to the blast furnace. The screening operation
separates fines, but these are recycled to the sintering machine.
Dusts are generated in two general locations in the process: (1) the
windbox where dusts are collected in the windbox hopper and in the final air
pollution control devices, and (2) the discharge-end where dusts are generated
by breaking, screening, and handling operations. Nearly all of the dust from
the windbox which is collected is recycled entirely within the sintering
operation. In some cases, the very fine dust which is collected by the bag-
house at the discharge-end is recycled as well; in other cases it is land-
filled. In any event, the quantity of this dust is comparatively small.
6.1.3 Blast Furnace Ironmaking
In the blast furnace, the various charge materials are delivered to the
top of the furnace and travel slowly down to the hearth. The operation is
39
-------
•fa-
O
13,600 Dust ^
(recycled to sinter)
179,000 Flux »•
34,000 Coke »
028,520 Ore »
105,000 Dust, Scale >
• 369,000 Sinter Finei fr
-182,000 Hearth layer >
111,500 Water +
Sinter
Plant
141,3CO Combustion, Calcination Gasos, Gaseous Emissions
111,500 Water Vapor
207 Dust to Air
Windbox
Exhaust
(dust laden)
9 Dust to Air
Baghouse
Cooling
Screen
Transfer
Hearth
Layer
182,000
Fines
369,000
900 Dust
(very fine dust,
most landfillod)
091,000 Sinter (to Blast Furnace)
Figure 11. Material flow for sinter plant in production of 2,500,000 tonnes of steel per year (oil numbers in tonnes).1
-------
essentially a continuous one, but molten iron is extracted at intervals of 3
to 4 hours. The charge normally consists of coke from the coke ovens, sinter,
pellets, lump ore, limestone, etc. An upward flowing current of hot air burns
the carbon and creates conditions in which the iron oxide is reduced to iron,
and flux is melted to remove impurities. When the furnace is tapped, the iron
is removed through one set of runners and the molten slag to another.
After iron, the greatest quantity of solid from the blast furnace is
slag. This material is usually crushed and processed to remove the entrained
iron which is recycled to the blast furnace. As will be noted in Figure 12,
approximately 90 percent of the slag is used as an aggregate concrete, road
ballast, etc. The remainder is disposed of in landfill operations.
The gas leaving the top of the furnace passes through a cyclone, commonly
called a dust catcher, and a high energy scrubber before it is diverted to
various fuel consumers such as the blast furnace stoves which heat the hot
blast, blast boilers which produce steam, etc.
Dry dust which is discharged from the dust catcher is recycled by means
of the sintering process. The same is true for some of the sludge which is
collected from the clarifier that serves the wet scrubbing system. However,
in the case of the sludge it is sometimes not used in the sintering plant
because of the somewhat greater difficulties experienced. The reasons for the
difficulties lie in the finer nature of the particles and in the oil which may
be contained in the sludge. This oil becomes vaporized in the sintering
process, thereby causing a visible emission at the windbox end which is very
difficult to capture.
Recent environmental regulations have necessitated total systems to
collect particulates of iron oxides and kish which are generated during the
casting of iron from the blast furnace. Kish is flakes of carbon emitted by
molten iron. These emissions, which amount to about 0.3 kg/tonne of iron, are
generally captured by baghouses and delivered in the form of dry dust. Most
blast furnaces in the United States at this time do not capture casting emis-
sions so that the addition of control equipment will cause an increase,
although slight, in the generation of solid waste.
41
-------
Water
High Energy
Wet Scrubber
4,153,600 Top Gas + Oust
25,400 DUST-
(recycled to sinter)
Dust
Collector
-p.
ro
691,000 Sinter
1,970.000 Ore, Pellets
128,000 Fluxes
900.000 Coke »
Z.647,000 Air Blast ».
Top Gas
+ Dust
Blast
Furnace
1
1,600,000 Hot Metal
(to steel making)
Settler
Clarifier
(Treatment)
Filter
"557,000 SLAG
(used as aggregate, cement, ballast)
Water Recycle
4,113,524 Top Gas (to stoves, boilers)
34 Dust
^Effluent
"42 Solids
"*• 40,000 SLUDGE
(5.000 landfill; 35.000 recycled
to sinter or stocked)
1ft t R
Figure 12. Blast furnace material flow in production of 2,500,000 tonnes of steel per year (all numbers in tonnes). '
-------
6.1.4 Basic Oxygen Steelmaking
As shown in Figure 13, the inputs to the BOF are molten iron (hot
metal), scrap, flux, and oxygen. The process is essentially a chemical one in
which a jet of pure oxygen impinges on the bath of molten iron to oxidize the
carbon and silicon in the iron thereby generating the heat necessary to melt
the scrap and purify the steel. The metallurgy of this batch process is
highly controlled and the results are quite predictable. The process cycle
time is called a heat and may be completed in 30 minutes to one hour.
Upon completion of the heat, the molten slag is poured into a pot which
is carried to the end of the shop, dumped on the ground, and cooled. Alter-
natively the slag can be carried from the shop to a remote area for disposal.
Magnetic separation is employed to recover metal!ics from the slag and recycle
them to the blast furnace. Because the slag is high in lime and dissolved
iron oxide, some companies recycle a portion of it back to the blast furnace.
In other facilities, the slag may be used for road ballast and the like;
however, most steelmaking slag is landfilled. Steelmaking slags may be wetted
and aged six months to stabilize them before they are suitable for construc-
tion fill.
The diagram of Figure 13 shows a wet gas cleaning system with associated
settler/thickener to remove fine oxide particulates from the offgas. These
particulates are very fine in size and, depending on the type of scrap used,
may contain significant quantities of zinc and lead. If so, it is usually not
feasible to recycle them to the sinter plant. Therefore, the majority of
steelmaking dusts from the BOF are either landfilled or stockpiled, thereby
losing a potentially valuable resource. Control of BOF emissions may be
achieved by a dry ESP, but the problem of solid waste disposal is essentially
the same as with the wet unit.
In addition to the gas cleaning system shown in Figure 13, a BOF usually
employs equipment for collecting kish from the pouring of molten iron into the
shop ladle and from the shop ladle into the furnace. There is also a trend
toward the provision of control equipment to capture fugitive emissions that
escape from the vessel mouth during the furnace blow and during tapping.
These emissions are covered in a subsequent section which relate to the effect
of future air pollution control on solid waste.
43
-------
1,600,000 Hot Metal-
499,000 Scrap
292,221 Flux
190,000 Oxygen
Basic
Oxygen
Furnace
290,000 SLAG
(iron recovered; estimate
50% used, recycled)
250,000 OFF-GAS
200 OUST
Water
WET
CLEANING
SYSTEM
-•-2,000,000 STEEL
Settler
Thickener
1
41,000 SLUDGE
(50% landfilled, balance stocked
or recycled)
Water Recycle
Effluent
21 Solids
•Nationally. 19'/« dry systems
6154 wet systems
20% semi-wet systems
Figure 13, Basic oxygen process material flow In production of 2.000,000 tonnes per year of steel (all numbers In tonnes).'8
-------
6.1.5 Electric Arc Steelmaking
In an EAF, steel is made by melting and refining scrap using electric
arcs struck from carbon electrodes. For the most part the solid wastes that
result from EAF operation are similar to those which are generated by the BOF.
The slag and its disposition as well as the steelmaking fumes and their
disposition are very similar to those materials in the BOF. The basic dif-
ference in the solid waste picture for the EAF is that there is little use of
molten iron and therefore, no system for recovery or disposal of kish. Figure
14 shows material flows for the production of 500,000 tonnes of steel per
year, equal to one-fifth the total production for the model plant.
Many EAF facilities are housed in completely enclosed buildings which are
vented to baghouses and collected particulates may be finer than that obtained
from the BOF. In addition, there may be carbonaceous and oily fumes which
result from the melting of oily scrap. Finally, because the electric arc
furnace relies solely on scrap and may be employed in the production of high
alloy steels, the dust may contain a higher percentage of zinc and other
metallies than is present in BOF dust.
6.1.6 Continuous Casting and Primary Rolling
Molten steel from the steelmaking furnace is tapped into a teeming ladle
from which it is poured into ingot molds or a continuous caster. In the ingot
mold route, the steel is partially cooled in the molds, the mold is stripped
from the ingot, the ingot placed in a soaking pit and reheated to rolling
temperatures, and then introduced into the primary rolling mill from which the
semi-finished product emerges. In the continuous caster, the steel is poured
through the mold which directly forms the semi-finished shape, the latter
passing through the bottom of the mold and cut into suitable lengths.
The yield of semi-finished steel is less in the ingot mold route than the
continuous casting route. This loss of yield is a result of two factors. (1)
The individual ingots after being rolled to the semi-finished shape contain im-
perfections which are rolled into the ends of the semi-finished shape. These
ends must be cropped and scrapped. (2) There is a loss of steel from oxide for-
mation in the soaking pit. This loss in yield in conjunction with the energy
required to fuel the soaking pit furnace, results in increased cost of
45
-------
521.000 SCRAP
45.640 FLUX
140 DUST
TO AIR
DRY
SYSTEM'
FUME
ELECTRIC
ARC
FURNACE
60,000 SLAG
(iron recovered, balance landf tiled,
10% other uses)
6,500 DUST (landfilled)
•+-500.000 STEEL (to shaping operation)
•Nationally, 76% dry systems
15% wet systems
9% semi-wet systems
Ifi
Figure 14. Electric arc furnace material flow in production of 500.000 tonnes of steel per year (all numbers in tonnes).
production as compared to the continuously cast semi-finished steel. In
consequence, continuous casting is gradually replacing the ingot mold-primary
rolling mill route of making semi-finished steel.
Both processes of converting molten steel into semi-finished steel result
in a generation of mill scale and scrap. The generation of these wastes is
much larger in the ingot route than in the continuous casting route. However,
in each case the wastes are essentially 100 percent recycled or stocked for
future use.
46
-------
The ingot method of making semi-finished steel results in an additional
solid waste in the soaking pit, called soaking pit scale or slag. This waste,
largely because of the refractory content, is landfilled. There are also
small amounts of iron oxide sludge which are produced and these are generally
landfilled. All of these situations are diagramed on Figure 15.
6.1.7 Hot and Cold Rolling
The process of converting semi-finished steel into a finished product
involves heating it in a reheat furnace followed by hot rolling to the desired
physical shape. In the case of structural shapes, the finished product is
most often taken from the hot mill, cut to specific size and sold. In the
case of strip and sheet, the hot roll product is sometimes sold; however, it
is often pickled, a process to remove scale by immersion in a bath of sulfuric
or hydrochloric acid and then cold rolled to achieve the desired character-
istics of gauge tolerance, surface finish, and metallurgy.
Figure 16 shows a typical sequence for producing steel from the finishing
mills. Steel, entering from the left of the diagram, passes through the hot
rolling process. A portion of it is sold directly from this process. Another
portion, approximately 39 percent is pickled, rinsed to remove the acid solu-
tions and cold rolled. Of the cold rolled products, approximately 68 percent
is sold directly from the mill and the remainder passes on to galvanizing,
tinning, and other coating processes.
The hot rolling finishing mills produce the same type of solid waste as
is produced in the primary mill. These wastes are scraps, mill scale, and
sludge. The difference between the waste products of the two types of mills
is that solid waste from the finishing mills are finer and smaller in quantity
than those from the primary mills. The disposal of wastes from both mills is
essentially the same.
There are two wastes which are produced by the pickling process, namely
waste pickle liquor and pickle rinse water. Both are acidic and contain
dissolved metallic compounds, principally iron. If sulfuric acid pickling is
used the metallic salt is ferrous sulfate; if hydrochloric acid is used it is
ferrous chloride. Either one, upon neutralization produces a sludge which
has little value, is typically impounded in lagoons, and is very difficult to
47
-------
80 F Steel
2,000.000
EAF Steel
500,000
Water
840,000
Steel
2,500.000
1,660,000
Continuous
Casting
43,000 Scrap
1
Recycle Water
790,000
Scale Pit
Filter
(95% tandlilledl
•Effluent
20.5 Solids
6,900 Scale (recycled or stocked)
Water
SO Sludge
Water
Recycle
Primary
Rolling
223,450 Scrap
Cropends
23,400 Soaking
Pit Scale
(landfilled)
1,350,000
Oil Skimmer
Scale Pit
Filter
L
240,000 Sales,
Transfers
Shapes
2,140.000
1,900,000
'To Hot Rolling
2,500 Sludge
(95% landfilled)
-*-E«luent
50 Solids
(oil recovered,
recycled)
60,600 Scale
(recycled or stocked)
Figure 15. Continuous casting, soaking, primary rolling material flow in production of 2,500,000 tonnes of steel per year (all numbers in tonnes).
16
-------
-p.
UD
1,098,000 Pickling
Wa
Steel ^
1,900,000
^
ter
Sales,!
t
Hot
Rolling
I
52,360 Scrap
\
i
£
r
Oil Skimmer
Scale Pit
Filter
3,100 J
i
F
'ransfers Soli
i
703,200^
\
ition Water
' i *
Siilfijrie fl?id „. x vVat^r
Pickling Rinse
Lime
Hluan* T '
*436 Solids
32,900 Scale
(recycled or stocked)
i >
Sludge
(95% landfillcd)
Waste Pickle Liquor f
to Ujitiide
Contractor
r
Neutrali-
zation
Lagoon
'
140,000 Sludge (Wet, Lagooned)
(est. 3,000 as iron)
Emulsion 125,000 to
Sp
i
ray Galva
t
700,220 r Cold
Rolling
Lcid Rinse Water
i
700,000
nizing
j, 475.000
Sales
100,000 Tin Plate
OH Skimmer
Neutrall-
z,ation
i '
-Water/Oil Recycled
73 Solids in Outfall
40 Scale
(landfill)
110 Sludge
(landfill)
Rgure 10. Hot and cold rolling In the production of on overall total of 2,500,000 tonnes of steel per year (all numbers In tonnes),
16
-------
dewater due to the formation of an iron hydroxide and water complex. Because
of the presence of various metallics, some of them heavy metals, the waste
may be considered hazardous.
An EPA survey of 16 plants revealed the following for spent liquor:
Recycled, regenerated, or reused 7.4%
Untreated disposal 60.8%
Neutralized on-site 20.5%
Contract hauler 11.3%
Untreated disposal includes deep-well injection, dumping on a slag pile, and
direct discharge. The quantity of sludge shown in Figure 16 (140,000 tonnes)
1Q
is the wet weight based on neutralizing spent sulfuric acid pickle liquor.
In the cold rolling operation, an emulsion of oil and water is used to
cool the rollers and the steel sheet as it is rolled thinner. The oil becomes
contaminated with scale and sludge. In the more modern mills, there are
internal facilities for purifying the oil so that it may be recycled. In
others, the oil is sent outside for reprocessing. In either case, it is
necessary to dispose of the waste scale and sludge. Because of the substan-
tial oil content, some of these wastes may be considered hazardous.
6.1.8 Finishing Operations
Finishing operations comprise a wide variety of operations including
metal forming, cutting and shearing, galvanizing, tin plating, etc. Electro-
galvanizing and tin plating (Figure 17) may produce scrap metal which is
recycled or otherwise reused. The latter operations may produce a solid waste
sludge which contains significant amounts of zinc, lead, tin, etc., depending
upon the nature of the process involved. These sludges originate from electro-
plating methods and are not formed in the hot dip technique. The value of the
metallic content is sufficient to economically justify recovery and recycle of
the metals, usually by an outside vendor. In the case of tin plating, even
the rinse water is sent outside for metal recovery. (The tin plating and
galvanizing sludge quantities are small and are based on generation factors for
sludge resulting from residuals from cleaning lines and from neutralization of
acid rinse water used in the plating operation at the water treatment plant.)
50
-------
Acid, Alkaline Dips
and Rinses
From Cold Rolling
225,000
100.000
Steel
125,000
Steel
Cleaning
Acid, Alkaline Dips
and Rinses
Cleaning
*• ~ 100,000 Tin Plated
Wastewater
Galvanizing
Rinsewater (Tin Recovered, Recycled)
Treatment
Plant
530 Sludge
(landfilled)
-*- ~ 125,000 Galvanized
^ Zinc Recovered, Recycled
Treatment
Plant
"Effluent
15.6 Solids
-»- Effluent
12.5 Solids
1,400 Sludge
(landfilled)
1 fi
Figure 17. Tin plating, galvanizing material fJow for 2,500,000 tonnes of steel per year (all numbers in tonnes).
-------
6.2 MAGNITUDE OF SOLID WASTE GENERATION
Using an annual output of 125 million tonnes of steel product as a basis,
the wastes produced are examined from the standpoint of the nation, individual
states, and specific geographical regions. The various wastes which are pro-
duced are categorized in such a manner as to reflect their alternate present
use, reuse, or disposal.
In dealing with steel plant wastes, a key consideration is the fact that
they are generally low in intrinsic value with respect to their weight. The
cost of transporting them any distance becomes a substantial percentage of
their ultimate value. It is, therefore, generally desirable to recycle the
wastes within the plant that produces them. One possible exception is scrap
iron which has a relatively high value and, under certain economic situations,
may be shipped over long distances. Other waste materials such as slag and
iron oxide, if not used within the plant that produce them, are normally
consumed in the immediate geographical area or disposed of on-site. The
implications of these facts will be examined in greater detail in subsequent
sections.
6.2.1 National Solid Waste Generation
In determining waste quantities, the first step was to establish the
tonnages produced by the individual processes for an ingot production of 125
million tonnes per year. These are presented in Table 14. The values were
developed from production data for the year 1977.
The corresponding quantities of solid wastes generated were estimated
using generation factors (emission factors) derived from data presented by
Dravo and Calspan. These factors are given in Tables 15 and 16. Minimum
and maximum quantities shown were obtained by examining the range of genera-
tion factors for individual plants listed the Dravo and Calspan report. '
The estimated quantity is derived from an average or typical generation factor
that was felt to be the most reliable and is referenced in Table 15. Applying
the generation factors of Table 15, the nationwide waste quantities for an
annual total production of 125 million tonnes of steel were calculated (Table
16).
52
-------
TABLE 14. INDIVIDUAL PROCESS OUTPUTS FOR PRODUCTION OF 125,000,000
=_= TONNES OF STEEL PER YEAR* (ALL NUMBERS IN TONNES)
BOF 77,400,000
OH Steel 19,700,000
EAF Steel 27.900,000
Total Steel Production 125,000,000
Coke 48,500,000
Sinter 35,100,000
Blast Furnace 81,300,000
Continuous Casting 15,300,000
Soaking 87,200,000
Primary Rolling 87,200,000
Hot Rolling 84,800,000
Cold Rolling 34,400,000
Galvanizing 5,300,000
Tin Mill 6,400,000
g
*Based on 1977 production.
Table 17 summarizes the annual generation of solid wastes for 125 million
ingot tonnes of production into four categories: (1) coke plant wastes, (2)
slag, (3) iron oxide wastes (including dusts), and (4) scrap.
As noted in the table, both coke breeze and metallic scrap are essen-
tially recycled or reused in a useful manner. From the standpoint of
disposal, these two items are taken care of, in most cases, by present
practices, and for this reason need no further consideration. Slag and iron
oxide wastes are not fully utilized and will be covered in greater detail.
6.2.2 Slags
There are two types of slag wastes, ironmaking and steelmaking. Table
18 shows the various components which make up a typical ironmaking slag and a
range of basic oxygen furnace steelmaking slags. There is a wide variation in
the range of compositions for the basic oxygen furnace slags. The nature of
the slag varies depending upon the metallurgy of the process involved, upon the
impurities in the feed materials to the process, principally sulfur, and upon
the end product. 53
-------
TABLE 15. WASTE GENERATION FACTORS AND QUANTITIES FOR A TYPICAL 2.500.000 TONNE YEAR/PLANT16'1*20
Quantity of Haste, tonnes/yr
Generation
Factor
Waste
Coke Breeze
Still Lime Sludge
Tar Sludge
Coke Treatment
Plant Sludge
Blast Furnace Slag
Blast Furnace Dust
Blast Furnace
Sludge
Blast Furnace Dust
and Sludge
EAF Slag
EAF Dust
BOF Slag
BOF Dust, Sludge
Sinter Fines
Sinter Dust
Continuous Casting
Scale
Continuous Casting
Sludge
Soaking Pit Scale
Primary Mill Scale
Primary Mill Sludge
Hot Rolling Scale
Hot Rolling Sludge
Minimum
17
345
11
3
25
25
2
230
16
6
,300
315
90
___
,600
,200
,200
,600
,000
,925
,000
,000
—
,910
158
—
—
—
—
—
—
RTI
32
1
556
25
40
65
60
6
290
41
369
14
6
23
60
2
32
3
Estimate
,400.
540
540
,530
,800
,360
,000
,460
,000
,500
,000
,000
,000
,511
,900
80
,400
,600
,500
,900
,100
Maximum
45
1
820
54
44
72
164
8
400
60
44
19
54
,000
540
540
,710
,800
,500
,800
,000
,500
,000
,000
,000
—
,224
,750
—
,900
—
—
—
—
(tonne/ tonne) Reference
of product Reference Product
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
.036 (1
.000604 (2
.0006 (3
.0017 (3
) Coke
1 Coke
Coke
Coke
.348 (2) Ironu
.01585 (1},(2) Iron
.025 (2), (4) Iron
.04085 (D,(2),(4) Iron
.120 (2) EAF Steel
.013 (1.
•145 . (2(
.0205° (V
.527 (3,
i EAF Steel
i BOF Steel
BOF Steel
Sinter
.021 (1) Sinter
.0087 (2) C.C. Steel
.000104 (2) C.C. Steel
.015 (3
.0449 (2
.00187 (2
S.P. Steel
P.M. Steel
P.M. Steel
.0183 (2) H.R.M. Ste
.00174 (2) H.R.M. Ste
-------
TABLE 15. fconf dl
Waste
Cold Rolling Scale
Cold Rolling Sludge
Galvanizing Sludge
Tin Plating Sludge
Bricks, Rubble
a, TOTALS
in
Quantity
Minimum
___
338
—
—
—
684,636
of Waste, tonnes/yr
RTI Estimate Maximum
40
110
1,350
530
250,000
1,885,151 1,791,264
Generation
Factor
(tonne/tonne)
of product
0.000052
0.00016
0.0108
0.00532
0.1
Reference9
(2)
(2)
(2)
(2)
(5)
Reference
Product
C.R.M.
Steel
C.R.M.
Steel
Finishing
Steel
Finishing
Steel
Total
Steel
(1) Dravo Corporation, 1976
(2) Calspan Corporation, 1977
(3) RTI Estimate
(4) Datagraphics, 1976
(5) AISI
Factor applies separately to dust and sludge.
cAlso agrees with the ratio of national slag to iron production.
-------
TABLE 16. NATIONWIDE WASTE GENERATION FOR 125,000,000 TONNES OF STEEL
PER YEAR (WASTE QUANTITIES IN THOUSANDS OF TONNES PER YEAR)
Disposition3
Waste
Coke Breeze
Ammonia Still Lime Sludge
Tar Sludge
Coke Treatment Plant Sludge
Blast Furnace Slag
Blast Furnace Dust
Blast Furnace Sludge
EAF Slag.
EAF Dust0
EAF Sludge
Open Hearth Slag
Open Hearth Dust
BOF Slag.
EOF Dust0
BOF Sludge
Sinter Fines
Sinter Dust
Continuous Casting Scale
Continuous Casting Sludge
Soaking Pit Scale
Primary Mill Scale
Primary Mill Sludge
Hot Rolling Scale
Hot Rolling Sludge
Cold Rolling Scale
Cold Rolling Sludge
Pickle Liquor Sludge
Galvanizing Sludge
Tin Plating Sludge
Scrap Metal
Bricks and Rubble d
Fly and Bottom Ash
TOTALS
Generated
1,750
30
30
80
28,300
1,290
2,030
3,350
290
70
4,790
270
11,220
490
1,100
18,500
740
130
1.6
1,310
3,920
160
1,550 "
150
2
6C
350C
60
30
42,300
12,500
380
137,179.6
Landfilled
0
30
30
80
2,800
170
270
2,550
280
67
2,400
160
5,600
250
550
0
40
0
1.1
1,310
0
150
0
140
2
6
350
60
23
0
12,500
380
30,199.1
Stocked
0
0
0
0
0
120
190
0
0
0
0
70
0
120
286
0
0
40
0
0
1,180
0
450
0
0
0
0
0
0
0
0
0
2,456
Recycl ed ,
Reused
1,750
0
0
0
25,500
1,000
1,570
800
10
3
2,400
40
5,600
120
264
18,500
700
90
0.5
0
2,740
10
1,100
10
0
0
0
0
7
42,300
0
0
104,514.5
16
20
Disposition is based on estimates by Calspan,1" Dravo,tu and RTI.
DEAF and BOF dust/sludge distribution based on number of wet and dry collection
systems used.
?n
cValue, 350, derived from Dravo estimate of 400 for 1974.
Based on coal usage for production of steam.
56
-------
TABLE 17. SUMMARY OF WASTEGENERATION FOR 125,000,000 TONNES OF STEEL PER YEAR (THOUSANDS OF
TONNES PER YEAR)a
Waste
COKE PLANT
Coke Breeze
Ammonia Still Lime Sludge
Tar Sludge
Water Treatment Plant
Sludge
Total
SLAG
Ironmaking
Steel making
Total
IRON OXIDE
Dust:
Sinter
Ironmaking
Steel making
Total
Sludge:
Ironmaking
Steel making
Mill
Total
Generated
1,750
30
30
80
1,890
28,300
19,360
47,660
740
1,290
1,050
3,080
2,030
1,170
758
3,958
Landfilled
30
30
80
140
2,800
10,560
13,360
40
170
690
900
270
617
730
1,617
% Stocked %
100
100
100
7
10
55
28
6
13 120 9
66 190 18
29 310 10
13 190 9
53 286 24
96
41 476 12
Recycled
or Used
1,750
1,750
25,500
8,800
34,300
700
1,000
170
1,870
1,570
267
28
1,865
%
100
93
90
45
72
94
78
16
61
78
23
4
47
-------
TABLE 17. (cont'd)
(Jl
00
Waste
Scale:
Soaking Pit
Mill
Total
Total Iron Oxide
SCRAP
Metallic Scrap
Rubble, Brick
Total
GRAND TOTAL
Generated
1,310
5,602
6,912
13,950
42,300
12,500
54,800
118,300
Landfilled
1,310
2
1,312
3,829
12,500
12,500
29,829
% Stocked
100
1,670
19 1,670
27 2,456
100
23
25 2,456
Recycled
% or Used
30 3,930
24 3,930
18 7,665
42,300
42,300
2 86,015
%
70
57
55
100
77
73
'Disposition is based on estimates by Calspan16, Dravo20, and RTI.
-------
TABLE 18. IRON AND STEELMAKING SLAGS
Ironmaking Slag
COMPOSITIONS - %
18
Basic Oxygen Furnace Slag
Slag Component
FeO
Si02
A1203
CaO
MgO
MnO
Cr2°3
P2°5
S
Other
Slag ratio (basicity)0
Average
___
35.3
12.8
41.2
8.3
—
1.4
1.0
1.03
Allegheny-Lud.a
20.7-26.4
20.4-22.9
0.7-1.2
39-40.8
9-10.2
2.7-3.6
0.4-0.6
0.3-0.6
0.03-0.04
—
2.1-2.3
Wheel ing-Pi tt.b
15-30
9-13
0.1-0.3
32-42
5-10
4-8
0.1-0.3
—
- 3.3-3.9
Based on two analyses, Pennsylvania Department of Environmental Resources
General ranges, Pennsylvania Department of Environmental Resources
cSlag ratio = (%CaO +• %MgO) * (%Si02 + %A1203)
Steelmaking slag differs from ironmaking slag in two essential respects.
The steelmaking slag contains significant quantities of iron oxide whereas
ironmaking slag contains less than 1 percent iron oxide. Also, the slag
ratio, or basicity, of steelmaking slag is considerably higher than ironmaking
slag. These two facts are important in relationship to the end use of the
slag. Because ironmaking slag is less basic, it is more useful for construc-
tion purposes such as road building, railroad ballast, and concrete aggregate.
In contrast, the steelmaking slag is not readily adapted to those purposes.
However, the iron content of steelmaking slag and its high basicity make it
useful for recycle as a charge material for the blast furnace. The chemical
composition of the two slags thus substantially affect their end use and
disposal.
59
-------
The slag data in Table 17 indicates that 90 percent of ironmaking slag is
recycled and 10 percent is land-filled. It would not be unreasonable to assume
that the land-filling operation, in large part, was carried out deliberately to
provide additional space in the steelmaking operations rather than as a
necessity to get rid of unwanted materials. For example, filling operations
are going on at one steel company on the shore of Lake Michigan and at another
on the Chesapeake Bay. In contrast, only 45 percent of the steelmaking slag
is reused whereas 55 percent is landfilled. Because steelmaking slag has high
basicity and is rather limey, care must be taken when placing it in the ground
that the disposal site is at a distance from a receiving body of water. If
such care is not taken, it is possible that a heavy rain may leach lime from
the slag and create an effluent which is high in pH.
6.2.3 Iron Oxide Solid Waste
In the steel industry the apparently nonhazardous solid wastes which
create the greatest disposal problem are iron oxide wastes. The production
and disposal of iron oxide waste is summarized in Table 17 in the categories
of dust, sludge, and scale. Within each category there are subcategories
which define the source of the waste as, for example in the case of dust,
sinter, ironmaking, and steelmaking. Each of these categories and subcate-
gories describe an iron oxide waste which is distinctive from the standpoint
of composition, particle size, moisture content, and contaminants. Each
presents its own problems, or lack of them, in respect to the potential for
recycle or reuse.
Tables 19, 20, 21, and 22 present chemical analysis of the blast furnace
dust, blast furnace sludge, BOF sand, and BOF fines respectively. An exam-
ination of these tables reveals a number of pertinent facts, as follows:
1. A particular solid waste, for example blast furnace dust,
is quite variable from facility to facility and even with-
in the facility itself. In the case of this dust, the
iron content varies from-5.9 to 54.0 percent, a spread
of almost one order of magnitude.
2. In a given process, the larger particles may have a sub-
stantially different composition than the finer particles.
For example, in the BOF under Plant E, the sands have an
iron content of about 33 percent whereas the fines have a
iron content of about 44 percent. The contrast is even
60
-------
TABLE 19. CHEMICAL ANALYSIS OF BLAST-FURNACE OUSTS
(percent by weight)
Reference
20
20
20
20
20
20
20
20
20
20
20
20
22
22
21
21
21
23
23
23
23
24
25
26
27
27
28
29
30
31
ID
C
E
F
H
1
L
MW
US
Primary
Secondary
O.K.
Germ.
U.S.
O.K.
O.K.
Low
High
Low
High
Low
High
Low
High
Low
High
Low
High
Low
High
Low
High
Low
High
Low
High
Low
High
Fe
31.4
38.2
29.0
31.3
49.4
54.0
25.8
35.6
16.8
20.8
20.4
46.8
36
50
47.1
36.5
50.3
20.0
49.9
5.9
43
32.2
27.0
23.6
31.5
51.0
50.0
29.0
43
39.2
C
28.5
32.4
34.4
36.1
17.3
20.3
44.8
50.7
28.7
43.7
20.0
53.6
3.5
15
n.d.
3.7
13.9
6.6
50.0
11.2
33.9
28.5
21.4
41.1
10.0
30.0
11.0
25.4
2.5
20.56
S
0.14
0.28
0.36
0.39
0.33
0.42
0.16
0.34
0.10
0.75
0.23
0.66
0.2
0.4
n.d.
0.2
0.4
n.d.
n.d.
n.d.
n.d.
0.2
n.d.
0.2
0.2
0.7
0.2
0.54
3.4
0.35
Pb Sn
0.01 0.01
0.01 0.04
0.02 <0.01
0.03 0.03
0.06 0.04
0.08 0.04
0.02 <0.01
0.03 0.02
0.01 0.04
0.01 0.04
0.05 <0.01
0.15 0.04
n.d.b n.d.
n.d. n.d.
n.d. n.d.
n.d. n.d.
n.d. n.d.
0.001 n.d.
0.28 n.d.
0.05 n.d.
3.4 n.d.
n.d. n.d.
0.01 n.d.
0.01 n.d.
0.2 n.d.
0.3 n.d.
0.1 n.d.
< 0.05 n.d.
0.02 0.01
0.01 5 < 0.01
Zn
0.07
0.09
0.05
0.12
0.17
0.21
0.01
0.03
0.01
0.02
0.02
0.02
n.d.
n.d.
0.5
n.d.
n.d.
0.08
2.7
0.08
11.5
0.45
0.05
0.08
0.7
0.8
is
0.15
0.4
0.08
Mn
0.06
0.15
0.11
0.16
0.04
0.04
0.04
0.08
0.42
1.52
0.15
0.20
0.5
1.0
0.7
0.5
0.9
n.d.
n.d.
n.d.
n.d.
0.5
.1.1
0.4
1.0
n.d.
0.34
n.d.
1.41
Na20
0.07
0.10
0.04
0.05
0.04
0.09
0.08
0.13
0.07
0.11
0.15
0.33
n.d.
n.d.
0.2
n.d.
n.d.
0.095
0.52
0.04
1.4
n.d.
n.d.
n.d.
n.d.
0.3
6.4
n.d.
0.32
K20
2.3
4.5
1.6
2.6
0.4
1.2
1.0
1.6
0.02
0.8
1.8
3.0
n.d.
n.d.
1.0
n.d.
n.d.
0.48
1.82
0.30
5.4
n.d.
n.d.
0.5
1.5
0.2
n.d.
n.d.
0.77
AI203
2.0
5.4
1.7
1.7
1.1
1.5
0.8
6.1
1.7
2.5
2.4
7.6
2
15
1.9
2.2
5.3
n.d.
n.d.
n.d.
n.d.
2.5
1.2
2.6
6.5
n.d.
13.2
3.8
1.37
CaO
4.2
5.4
2.4
3.0
1.8
6.0
2.7
5.4
7.1
8.7
3.7
11.0
3.8
28
4.1
3.8
4.5
n.d.
n.d.
n.d.
n.d.
3.1
5.2
6.0
7.0
4.5
9.4
n.d.
5.38
MgO
2.2
3.0
1.1
1.2
2.4
3.1
0.6
1.8
1.9
2.5
2.1
2.6
0.2
5
0.2
0.9
1.6
n.d.
n.d.
n.d.
n.d.
0.7
2.2
1.0
2.0
0.3
0.07
n.d.
1.93
SiO, As Sb Se
7.6 <0.02 <0.01 <0.01a
5.2 <0.02 <0.01 <0.01
E.4 0.02 0.01 0.01 [sic]
5.4 <0.02 <0.01 <0.01
11.1 <0.02 <0.01 <0.01
7.2 <0.02 <0.0t <0.01
8
30
8.2
8.9
13.4
n.d.
n.d.
n.d.
n.d.
6.9
7.3
9.8
11.0
6.S
11.6
n.d. 0.001
7.28
aSi02, As, Sb, and Se shown (or only one sample.
Not determined.
-------
TABLE 20. COMPOSITION OF BLAST-FURNACE SLUDGE, PERCENT BY WEIGHT (DRY BASIS)
ro
Reference
20
20
20
20
20
20
20
20
20
20
20
20
24
32
32
27
21
10
C
D
E
F
1
M
Japanese
Japanese
German
UK
USA
Low
High
Low
High
Low
High
Low
High
Low
High
Low
High
c
d
e
f
Fe
25.6
29.4
21.8
40.7
43.0
38.9
39.6
24.7
30.2
27.5
35.6
45
28.6
27.5
40.2
61.0
33.6
42.9
10.1
13.5
6.0
C
27.7
29.8
40.9
21.1
24.3
18.3
18.9
30.2
40.5
20.9
35.1
5.5
40.8
17.8
1.1
16.0
23.3
15.6h
_
16.0h
-
S
0.19
0.47
0.25
0.46
0.46
0.78
0.94
0.25
0.68
0.63
1.01
4.6
0.3
2.0
0.08
0.3
—
0.4
1.9
1.3
1.4
Pb
0.09
0.13
0.10
0.13
0.19
0.09
1.02
0.04
0.05
0.05
0.07
0.03
-
4.2
_
-
0.3
-
_
—
• , " -Tm
Sn
<0.01
0.01
0.06
0.02
0.03
0.04
0.05
0.02
0.03
0.01
0.03
0.01
-
n.d.
_
-
—
-
_
—
Zn
0.50
1.11
1.6
0.26
0.38
2.1
2.6
0.04
0.07
0.08
0.14
0.2
0.5
9.5
0.2
0.3
0.7
O9
1.2
0.9
1.2
Mn
0.06
0.14
0.07
0.10
0.17
0.01
0.02
0.10
0.29
0.06
0.17
b
0.3
—
-
0.4
0.49
1.67
0.85
1.15
N,20
0.05
0.08
0.11
0.04
0.04
0.08
0.09
0.03
0.04
0.03
0.08
-
-
—
-
—
0.2
9.2
1.6
9.8
K20
1.1
1.9
1.9
0.9
1.2
0.6
0.9
0.4
0.6
0.6
1.2
-
-
—
-
0.5
0.6
20.9
2.7
22.4
AI2°3
3.6
4.7
2.6
2.1
3.1
0.3
0.3
1.7
2.2
1.8
2.3
6.2
3.0
2.1
3.9
2.8
4.4
6.9
15.6
6.7
CaO
4.4
3.0
3.2
2.8
3.2
3.5
4.0
4.0
5.6
4.7
8.2
7.7
2.7
3.1
4.6
7.5
3.6
6.4
7.1
4.7
MgO
2.4
1.8
0.9
1.2
2.2
2.3
1.5
2.0
1.2
1.9
-
0.7
0.9
5.9
1.1
1.7
8.0
9.9
9.3
S!02 As Sb Si
9.3a <0.02a <0.01a <0.01a
9.7 <0.02 <0.01 <0.01
6.28 <0.028 <0.018 <0.01a
6.5a <0.02a <0.018 <0.01a
7.88 <0.02a <0.01a <0.018
7.58 <0.028 <0.01a <0.01a
0.007
6.1
4.1
8.5
10.5
. ... . .„ -_-j. — —
0 Determined (or only one sample.
Blanks mean not determined or not reported.
c Sludge from washers.
Dust in gas leaving washers.
e Sludge from wet precipitator.
Dust in gas leaving precipitator.
9 Not detected by standard methods.
Loss on ignition.
-------
u>
TABLE 21. CHEMICAL ANALYSES OF BOF RESIDUES-SANDS20
(weight %-dry)
Plant
Ab
Ec
1
J
Sample
Filter cake8
1
2
Sludoob
1
2
Sludged
1
2
3
4
Sludgod
1
2
3
4
Fe
59.1
50.6
35.0
32.4
52.9
46.1
47.3
55.5
53.7
66.4
61.6
59.3
C
0.9
1.8
1.0
2.0
1.6
1.1
1.0
0.9
0.6
0.4
0.7
0.5
S
0.02
0.04
0.06
0.08
0.10
0.09
0.06
0.02
<0.01
<0.01
0.01
0.01
Pb
0.02
0.2.1
0.01
0.02
<0.01
0.01
<0.01
<0.01
<0.01
<0.01
0.01
0.01
Sn
0.10
0.10
0.02
0.04
0.02
0.02
0.01
0.01
<0.01
0.01
<0.01
0.01
Zn
0.01
0.01
0.3
3.3
0.01
0.01
0.01
0.01
0.03
0.05
0.05
0.08
Mn
0.61
0.52
0.67
0.72
0.32-
0.28
0.36
0.88
0.16
0:25
0.47
0.33
Na20
0.03
0.11
0.03
0.03
0.04
0.03
0.03
0.01
0.01
<0.01
0.01
0.01
K20
0.03
0.18
0.14
0.16
0.08
0.07
0.05
0.05
0.01
0.01
0.01
0.01
AI203
0.13
0.38
0.62
0.53
0.25
0.21
0.25
0.25
0.15
0.08
0.13
0.15
CaO
15.9
11.4
23.7
20.8
16.1
15.2
15.4
13.8
5.4
2.8
5.4
9.2
MgO
2.0
1.8
2.1
1.6
8.3
4.8
5,7
3.6
1.7
0.79
1.8
2.1
Si02 As Sb Se
3.4 <0.02 <0.01 <0.01
13.0 <0.02 <0.01 <0.01
2.8 <0.02 <0.01 <0.01
3.7 <0.02 <0.02 <0.01
8 Rake classifier and scrubber fines combined.
b Settling basin.
CQ-BOP
Rake classifier.
-------
TABLE 21 CHEMICAL ANALYSES OF BOF RESIDUES-FINES20
(weight %-dry)
en
4*
Plant
Ea
F
G
1
K
*Q-BOP.
b Scrubber.
CESP.
Sample
Sludgeb
1
2
Du$tc
1
2
Sludge13
1
2
3
4
Sludge5
1
2
3
4
Sludgob
1
2
3
4
Fe
45.2
43.9
58.3
60.4
60.2
60.7
61.9
61.8
55.6
56.5
57.4
55.6
53.4
61.2
57.5
56.2
C
2.9
3.1
0.7
0.5
1.4
1.5
1.3
1.2
1.7
1.4
1.3
1.6
1.5
1.5
1.1
2.6
S
0.18
0.44
0.04
0.01
0.20
0.17
0.15
0.13
0.14
0.13
0.13
0.11
0.10
0.10
0.07
0.15
Pb
0.13
0.09
0.05
0.04
1.8
1.7
1.6
1.4
0.04
0.07
0.06
0.05
0.73
0.60
0.29
0.60
Sn
0.02
0.04
0.02
0.03
O.OS
0.04
0.04
<0.01
<0.01
<0.01
<0.01
<0.01
0.05
0.02
0.01
0.02
Zn
12.8
13.7
0.24
0.12
2.0
1.7
1.6
1.4
0.07
0.07
0.09
0.07
4.5
3.5
1.4
3.7
Mn
0.58
0.55
0.12
0.13
0.50
0.52
0.41
0.37
0.36
0.50
0.59
0.34
0.12
0.08
0.14
0.35
Na20
0.07
0.05
0.27
0.35
0.11
0.07
0.07
0.07
0.11
0.09
0.11
0.09
0.16
0.13
0.11
0.13
K20
0.27
0.23
1.2
0.70
0.31
0.29
0.22
0.27
0.12
0.12
0.12
0.12
0.35
0.47
0.27
0.37
AI203
0.30
0.25
0.09
0.08
0.08
0.09
0.11
0.08
0.11
0.08
0.08
0.09
0.17
0.55
0.17
0.25
CaO
5.6
5.9
7.6
6.0
3.6
4.2
3.4
3.6
6.9
6.1
5.7
6.5
6.0
8.9
6.4
4.6
MgO
0.66
0.60
0.61
0.61
0.98
0.99
0.80
0.75
2.0
2.4
2.0
2.6
1.1
1.2
1.4
1.0
Si02 As Sb Se
1.8 <0.02 <0.01 <0.01
2.8 <0.02 <0.01 <0.01
1.6 <0.02 <0.01 <0.01
2.3 <0.02 <0.01 <0.01
2.0 <0.02 <0.01 <0.01
-------
more marked in respect to zinc content in which the sands
have a zinc content of 2 percent and the fines a zinc con-
tent of about 13 percent.
Physical characteristics of the wastes are almost as important as chemical
compositions. The fine participate sludges are much more difficult to recycle
than the coarse dry dusts. If oil is present in any substantial quantity
along with the sludge, difficulties are imposed on the sintering process.
Table 17 indicates that, of the total iron oxide in all categories, 55
percent is recycled or reused and 45 percent is landfilled or stocked. In
this connection, the word "stocked" should be used with some discretion. In
some steelmaking facilities, where iron oxide is said to be stocked for a
future use, this indeed represents a true fact. In other plants the same
terminology may be used as euphemism when disposal is the actual intent.
If steelmaking dusts and sludges are considered by themselves, of a total
generation amounting to 2.2 million tonnes per year, 80 percent is either
landfilled or stocked and only 20 percent is reused. Many problems are
associated with recycling these wastes. A few of the key ones are as follows:
1. Zinc and lead in the dust are carried into the sinter and
from there to the blast furnace, where it interferes with
flue operations of the blast furnace and causes premature
destruction of the furnace lining.
2. The very fine particulates cause handling problems and
interfere with smooth operations of the sintering process.
3. The iron content of steelmaking fines is usually small
although often highly variable.
4. The tonnage of waste iron oxide generated in a single steel-
making facility is too small to economically support a
sophisticated and technically correct process for recovering
the waste and converting it to a useful form. For this
reason, there have been investigations into the regional
concept of treating these wastes, bearing in mind that their
relatively low intrinsic value is an impediment to trans-
porting them any distance. Thus, any regional concept can
serve only a limited geographical area. This concept is dis-
cussed further in Section 6.2.5.
65
-------
6.2.4 Solid Waste Generation by State
Table 23 provides information on the distribution of iron and steel-
making capacity by state. In preparing the Table, the capacity values reported
to EPA by each plant in the United States were summed to obtain a total of 158
4
million tonnes. This total was then adjusted to the AISI industry estimate of
143 million tonnes (158 million tons).
In recent years production has been less than capacity and, therefore,
Table 24 shows the waste that would be generated in each state if the national
production were 125 million tonnes per year. This provides a numerical re-
ference point that, in any given year of the current decade, is close to actual
production.
This production was then multiplied by the generation factors of Table 15
to obtain the waste generations shown in Table 24. Examination of the Table
indicates that the first five states listed, Pennsylvania, Indiana, Ohio,
Illinois, and Michigan account for over 70 percent of the total solid waste
produced.
6.2.5 Solid Waste Generation by Geographical Region
There are six geographical regions in the United States in which the
density of iron and steelmaking facilities is high. These regions, in their
order of density, are Chicago, Pittsburgh, Cleveland, Philadelphia, Youngstown,
and Birmingham. Table 25 analyzes the generation of slag, iron oxide waste,
and organic sludge for each of the geographical regions based on an annual
national production of 125 million tonnes. The data on slag and organic
sludge is presented for general information. The data on iron oxide waste is
of more significance because it provides the basis for regional plants specifi-
cally designed to process them.
Table 26 shows the quantities of iron oxide wastes available for treatment
in a regional plant. These quantities are now landfilled or stockpiled. They
were determined by subtracting the quantities recycled from the quantities
generated (Table 25). Percentage recycle for sludge is 47; for dust, 61; and
for scale, 57.
Table 27 indicates some of the economic considerations which go into the
evaluation of the regional treatment concept. It assumes that commercial
66
-------
TABLE 23.
ESTIMATED STATE DISTRIBUTION OF IRON AND STEEL CAPACITY
fTuniKflNrv; nc TnwMircW'^
OF
STEELMAKING CAPACITY
State
Pennsylvania
Indiana
Ohio
Illinois
Michigan
Maryland
Texas
New York
Al abama
West Virginia
California
Kentucky
Utah
Colorado
Missouri
South Carolina
Washington
Georgia
Florida
Delaware
New Jersey
Tennessee
Oklahoma
Oregon
Connecticut
Nebraska
Mississippi
Minnesota
Iowa
Arizona
Arkansas
North Carolina
Rhode Island
Hawaii
Virginia
Wisconsin
TOTAL
No. of
Plants
44
7
19
15
6
3
12
9
6
2
9
4
1
1
1
3
3
2
3
1
2
2
1
1
1
1
1
1
1
1
1
1
1
1
1
1
169
Blast
Furnace
21 ,392
18,493
16,105
8,343
8,118
5,559
993
3,681
3,345
2,313
2,102
1,635
1,664
1,257
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
95,000
Basic
Oxygen
14,428
21 ,004
14,812
9,603
9,466
2,867
0
4,031
3,735
3,656
1,200
2,086
0
1,430
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
88,318
Electric
Arc
6,647
925
3,993
4,483
1,905
136
4,181
497
346
275
753
647
0
300
889
745
717
616
582
434
376
330
312
234
208
208
186
156
150
130
121
120
55
52
52
52
31,813
Open
Hearth
7,992
1,910
4,970
0
0
2,831
1,003
273
0
0
1,794
0
2,093
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
22,866
Total
Steel
29,067
23,839
23,775
14,086
11,371
5,834
5,184
4,801
4,081
3,931
3.747
2,733
2,093
1,730
889
745
717
616
582
434
376
330
312
234
208
208
186
156
150
130
121
120
55
52
52
52
143,000
67
-------
TABLE 24. ESTIMATED STATE DISTRIBUTION OF WASTES GENERATED FROM 125,000,000
TONNES STEEL PRODUCTION (ALL NUMBERS IN THOUSANDS OF TONNES)
State
Pennsylvania
Indiana
Ohio
Illinois
Michigan
Maryland
New York
Texas
A1 abama
California
West Virginia
Utah
Kentucky
Colorado
Missouri
South Carolina
Washington
Georgia
Florida
Delaware
New Jersey
Tennessee
Oklahoma
Oregon
Connecticut
Nebraska
Mississippi
Mi nnesota
Iowa
Arizona
Arkansas
North Carolina
Hawai i
Rhode Island
Virginia
Wisconsin
TOTAL
Slag
10,404
8,554
8,056
4,124
3,768
2,605
1,695
1,540
1,484
1,228
1,164
933
809
580
95
79
76
65
62
47
40
36
34
25
22
22
20
17
16
14
13
13
6
6
6
6
47,664
Sludge
839
827
687
383
354
201
66
57
152
88
125
49
79
55
4
2.8
3.5
3.1
1.9
1.7
1.6
1.4
1.1
1.1
1.0
0.8
0.7
2.0
0.5
0.6
0.4
0.4
0.3
0.3
0.3
0.3
3,990
Dust
694
556
452
273
207
231
91
80
111
82
92
61
51
39
8
7
6.8
5.8
5.5
4.1
3.5
3.1
2.9
2.2
2.0
2.0
1.7
1.5
1.4
1.2
1.1
1.0
0.5
0.5
0.5
0.5
3,083
Scale
1,510
1,151
1,184
679
505
312
232
244
192
195
148
122
136
88
39
20
42
28
11
11
14
13
7
14
12
4
4
9
3
8
7
2
3
3
3
3
6,958
68
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TABLE 25. WASTE GENERATION BY GEOGRAPHICAL REGION
No. of
Region Plants
Chicago (includes
Northern Indiana)
Pittsburgh (includes
Weirton, WV, and
Steubenville, OH)
Cleveland (includes
Lorain, OH)
Philadelphia
15
27
.4
5
Center
South Chicago
Pittsburgh
Cleveland
Fairless Hills
Maximum
Miles
To Slag
Center
30
40
22
60
11,774
8,709
3,102
2,747
Iron
Oxide
SI udge
Iron
Oxide
Dust
Scale
(thousands of tonnes)
996
673
265
173
748
312
153
187
1,467
1,166
415
356
Organic
Sludge
28
41
8
7
(includes Bethle-
hem, PA)
2 Youngstown, OH
(includes Warren,
OH)
Birmingham, AL
(includes Gadsden,
AL)
Youngstown
Birmingham
10 1,824 114
55 1,503 132
122
111
309
192
11
-------
TABLE 26. IRON OXIDE WASTES AVAILABLE FOR REGIONAL TREATMENT (NOT PRESENTLY
RECYCLED)
Geographical
Region
Chicago
Pittsburgh
Cleveland
Philadelphia
Youngstown
Birmingham
Recovery Plant
Location
South Chicago
Pittsburgh
Cleveland
Fairless Hills
Youngstown
Birmingham
Available Iron Oxide Quantities
(thousands of tonnes per year)
Sludge
528a
357
140
92
60
70
Dust
292b
200
60
73
48
43
Scale
631°
501
178
153
133
83
Total
1,451
1,058
378
318
241
196
Based on 47% recycle of generated sludge.
Based on 61% recycle of generated dust.
cBased on 57% recycle of generated scale.
TABLE 27. ORDER OF MAGNITUDE ESTIMATE OF REGIONAL PLANT ECONOMICS
Per Tonne of Waste
1.
Pellets produced at $25/tonne iron content;
(assumes 56% iron content of waste)
2. Zinc recovered at $204/tonnei
(assumes 6% zinc content and 90% recovery)
3. Landfill Charge
4.
5.
6.
Minus Production Cost
TPY of waste)
Gross Value
TOTAL $ GENERATED
16
(for 350,000 dry
$
$
$
14.00
11.02
1.50
26.52
- 23.32
3.20
16
If the waste transportation cost is $0.06/tonne-mile, at the break
even value the waste can be transported 53 miles ($3.20 * 0.06) from
the source to the treatment plant.
70
-------
quality pellets will be produced from iron oxide dust at $25 per tonne of iron
content and that zinc will be recovered at $204 per tonne. If the iron pellets
are prereduced in the process, the value will increase. The landfill charge
of $1.50 per tonne is the assumed present cost of disposing of the iron oxide.
As noted, the production costs for the plant, excluding transportation, were
obtained from data provided by Calspan.16 The calculation indicates a poten-
tial gross value of $3.20 per tonne of waste. This would allow, at break even
value, the waste to be transported 53 miles from the source of generation to
the treatment plant. No transportation costs are provided for the finished
product because it is assumed that the treatment plant would be located
adjacent to the ironmaking facility where the product could be used.
The data in Tables 26 and 27 must be used with care. They represent a
first order of magnitude approximation to the economics of the process. Some
factors which may upset the calculations are given below:
1. The percent usage factor in Table 26 is an average for the
entire industry. The particular percent usage will vary
from plant to plant and from one geographical region to
another.
2. The value of the pellets will vary depending upon whether
or not they are prereduced.
3. The production costs, including capital, will vary from area
to area depending upon labor rates, fuel costs', etc.
4. The production costs will vary from region to region depending
upon the size of processing plant. The larger the production
throughput of the plant, the smaller will be the unit cost.
5. Within a region, the cost of transporting the waste from the
originating plant to the process plant will depend not only
on the distance, but also upon the available method of
transport, whether trucks, railroads, etc.
In spite of the uncertainties in the economics as listed above, the rough
calculation indicates that the concept of a regional plant for processing iron
oxide waste may have value in certain specific locations in the United States.
6.3 SOLID WASTE PROJECTIONS
The information in the preceding sections covered the present conditions
in the iron and steel industry in regard to the generation and disposition of
nonhazardous solid waste. This section provides a projection of the growth
71
-------
that may be anticipated in the future. The projections are based on the
expected impact on solid waste generations, of air and water pollution control
regulations, and expected changes in steel production.
6.3.1 Effect of Air Regulations
In order to determine the maximum possible effect that implementation
of air pollution control may have on the generation of solid waste, calcula-
tions were made on the assumption of 100 percent future control. This degree
of control is not likely to be achievable but its use provides an estimate of
the maximum amount of solid waste that may be produced by the imposition of
new regulations.
Table 28 presents calculations on present particulate pollution for five
processes, namely coke plant, sinter plant, blast furnaces, BOF, and electric
arc furnaces. Present air pollutant loads would become additional solid waste
under future control. Not included in these calculations is the consideration
of fugitive emissions from storage piles, road traffic, etc. It is recognized
that these fugitive emissions may be comparatively large in quantity; however,
the type of control envisioned would not generate solid waste. Such control
would include elimination of emissions at the source, equipment modifications,
sweeping and wetting down of roadways, watering of storage piles, etc. Such
controls would tend to retain the dust at its source of generation, rather
than transferring it to a solid waste disposal problem.
The five processes were chosen as those that would contribute the most to
solid waste generation through additional air pollution control. This is a
simplification in that removal of non-particulates may also generate some
additional solid waste in water treatment facilities. However, non-particu-
late removal is not expected to contribute a significant quantity relative to
the assumed 100 percent control of the five processes shown.
Table 29 presents a summary of additional solid wastes which would be
generated by the entire industry under future more stringent air regulations.
It is assumed that the waste from the coke plant being essentially carbon
wastes, could be recycled within the confines of the producing plant. The
iron oxide wastes would be very fine and quite difficult to treat; however,
the tonnage is very small in comparison to the tonnage of solid waste that is
72
-------
TABLE 28. ESTIMATED DUST GENERATION TO AIR UNDER PRESENT CONTROLS
1. Coke Plant 48,500,000 tonnes/yr .|
Emission Factor: 1.0 kg/tonne pushing -,
2.0 kg/tonne quenching
Dust Emitted: 145,500 tonnes/yr
2. Sinter Plant 35,100,000 tonnes/yr
Emission Factor: 0.16 kg/tonne of feed
Dust Emitted: 11,870 tonnes/yr
3. Blast Furnace 81,300,000 tonnes/yr „
Emission Factor: 11 mg/scm from flue gas
0.3 kg/tonne from cast house
Dust Emitted: 26,117 tonnes/yr
4. Basic Oxygen Furnace 77,400,000 tonnes/yr b
Emission Factor: 0.1 kg/tonne from offgas
0.48 kg/tonne from tapping,5
charging, metal transfer
Dust Emitted: 44,890 tonnes/yr
5. Electric Arc Furnace 27,900,000 topnes/yr
Emission Factor: 0.28 kg/tonne
Dust Emitted: 8,590 tonnes/yr
a8 of 9 plants in EPA survey had emissions less than 0.16 kg/tonne feed.
bWorst case in EPA survey of 5 plants.
cWorst case in EPA survey of 6 plants.
TABLE 29. IMPACT OF FUTURE AIR REGULATIONS ON SOLID WASTE ,
Additional Quantities of Solid Waste (tonnes/year)5
Carbon Wastes Iron Oxide Wastes
Process (tonnes/yr) (tonnes/yr)
Coke Plant 145,500
Sinter Plant . — 11,870
Blast Furnace — 26,117
Basic Oxygen Furnace — 44,890
Electric Arc Furnace — 8,590
TOTALS 145,500b 91,467
Present Process Waste Landfilled 17,189,000
% Increase " 0-5
aEstimate is for national total production rate of 125,000,000 tonnes of steel
per year.
It is anticipated that coke plant wastes will be recycled.
cLandfilled waste excluding rubble and brick.
dAssumes strictest possible regulations, that is, zero emissions.
73
-------
presently being land-filled. The impact of future air regulations on process
waste is an increase of 0.5 percent.
6.3.2 Effect of Water Regulations
Table 30 provides an analysis of the generation of solid waste which
results from compliance with future water pollution control regulations for
the iron and steel industry. Two simplifying assumptions were made in computing
the data in the Table. The first is to assume that the industry presently
generates solid waste derived from wastewater treatment equivalent to the 1977
water pollution control regulations. Even though the effluent quality for
some plants still does not comply with these regulations, other effluents in
compliance exceed them in other respects. Therefore, for the purpose of
estimating sludge generation, this first assumption is reasonably close to the
current situation. A check with the EPA Permits Division in November 1978
revealed that only 20 plants are not meeting the 1977 regulations and are on a
timetable for compliance. The second simplifying assumption is that the
ultimate control imposed upon the steel industry will generate no more solid
waste than from the 1983 regulations. If control requirements extend beyond
these regulations, for example to include the concept of "zero discharge,"
there will be a substantial increase in the tonnage of solid waste, greater
than indicated by the Table.
Table 30 indicates that the imposition of future water pollution control
measures will create 29,700 tonnes annually from suspended solids. Assuming
that these are not recycled, they will add approximately 0.2 percent to the
process wastes which are presently landfilled.
6.3.3 Effect of Industry Growth
Projections of growth in the iron and steel industry have, in recent
years, been invariably wrong. In 1974, for example, experts were predicting a
phenomenal growth. At the present time, many experts are seeing a leveling
off, or perhaps even a decline. Nevertheless, the current consensus is that a
37
2.5 percent growth in production appears to be reasonable. IF steel indus-
try production grows by 2.5 percent, then it is reasonable to expect that the
generation of solid waste will grow by approximately the same amount.
74
-------
TABLE 30. IMPACT OF FUTURE WATER REGULATIONS ON SOLID WASTE19'38
Operation
BPCTCA (1977)a BATEA (1983)'
(Suspended Solids kg/tonne)
Product New Sludge*
(tonnes/yr) (tonnes/yr)
Coke
Blast Furnace
Basic Oxygen
Electric Arc
Continuous Casting
Primary Mill
Hot Rolling
Pickling
Cold Rolling
Galvanizing
Tin Plating
Present Process Waste
% Increase with 1983
0.0365
0.0260
0.0104
0.0104
0.0260
0.0371
0.2420
0.0469
0.1042
0.1250
0.1250
Landfilled
Regulations
0.0104
0.0130
0.0052
0.0052
0.0052
0.0011
0
0.0026
0.1042
0.0104
0.0104
17,189,000
0.2
48,500,000
81,300,000
77,400,000
27,900,000
15,300,000
87,200,000
84,800,000
34,400,000
34,400,000
5,300,000
6,400,000
tonnes/yrc
1,266
1,057
402
145
318
3,139
20,522
1,524
0
607
733
29,713
*New Sludge = (BPCTCA - BATEA) x Product
aBPCTCA - Best Practicable Control Technology Currently Available
bBATEA - Best Available Technology Economically Achievable
cLandfilled waste excluding rubble and brick.
An estimate of waste generation is provided in Table 31 and is based on a
yearly growth rate of 2.5 percent. The impact of air and water regulations
that was discussed in previous sections has been included in the dust and
sludge estimates.
TABLE 31. PROJECTED WASTE GENERATION IN 1983
(MILLIONS OF TONNES)
Waste
Slag
Dust, Sludge
Scale
1977
43.3 •
6.4
6.3
1983
50.3
7.6
7.3
75
-------
In summary, the projection for growth in the generation of solid waste
from iron and steel making is as follows:
1. from air regulations 0.5 percent,
2. from water regulations, 0.2 percent, and
3. from production growth, 2.5 percent per year.
76
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7.0 THE ENVIRONMENTAL IMPACT OF IRON AND STEEL SOLID WASTES
This section describes the current waste disposal practices of the iron
and steel industry and identifies sources of environmental impact from these
practices. The impact of the criteria for sanitary landfills on the iron and
steel industry is assessed and alternative disposal practices are identified
which would be in compliance with Section 4004 of RCRA.
Solid wastes are currently defined to include not only solids and liquids
which are not reused, but also solids and liquids which are reused if the
material is placed into or on any land or body of water such that any con-
stituent may enter the environment. This broad definition of solid waste
could include such facilities as raw material storage, waste treatment lagoons,
slag processing facilities, and leaking pipes or sewer lines. Although the
environmental impact from each of these solid wastes cannot be assumed to be
negligible, the only solid waste disposal which has been considered is
conventional landfill ing.
Current landfill operations are generally conducted such that any leachate
which is formed may enter the groundwater, but some of the wastes have been
put in lined landfills with leachate collection. Most of the nonhazardous
waste is estimated to be disposed of on-site with approximately 30 percent
disposed of off-site and 6 percent handled at contract disposal sites.
The water extract of various iron and steel wastes contain components
which can, under some circumstances, endanger health when ingested in drinking
water in high enough concentrations. Some of these components include oil,
cadmium, chrominum, lead, mercury, phenols, and cyanide. There is a variability
not only among different types of wastes, but also among various samples of
the same type of waste. The proposed rules not only require the groundwater
at the property boundary to meet any promulgated National Interim Primary
Drinking Water Standard, but it also requires that the water not be made un-
fit for human consumption, which includes aesthetic as well as health factors
53
not currently regulated. The use of lined landfills for steel wastes with
77
-------
controlled discharge of the collected leachate is assumed, since this method
of landfill operation would restrict the contamination of groundwater by the
leachate.
7.1 TREATMENT AND DISPOSAL PRACTICES
The types of disposal practices utilized in dealing with steel industry
solid wastes have been broken down into three categories: (1) reuse or re-
cycling, (2) stockpiling for potential reuse, and (3) dumping with no intent
for reuse. For the category of dumping, the general term "landfill" has been
used to describe a solid waste dump site to avoid overlapping or ambiguous
terminology. Within the disposal site may be pits, lagoons, ponds, basins,
filled-in ravines, mounds, or heaps of varying size and number. These sites
that are used by the steel industry are usually large land areas that receive
solids, liquids, and sludges, and for the most part, are not lined facilities
designed to prevent leachate movement with provisions for leachate collection
and groundwater monitoring.
7.1.1 Slag Treatment and Disposal
Slag is a waste generated by iron and steelmaking but serves as a
valuable raw material for the slag processing industry. It is processed at
101 major iron and steel furnace slag plants and also at an undetermined
number of smaller plants Some of the major processors and their locations are
listed below:39
International Mill Service Heckett Co. (CA, IN, NY)
IL> E.G. Levy Co. (MI, IN)
U.S. Steel Corporation R,,**ai« ci=»n f*nn
(WV, PA, OH, UT, IL) Buffal° Slag (NY)
Duquesne Slag (PA) Vulcan Materials (AL, IN)
Blast furnace (iron) slag is sold as three general physical types: air-
cooled, granulated, and expanded. Air-cooled slag is produced by pouring
molten slag into a slag bank or pit; after solidifying and cooling, the slag
is excavated, crushed, and screened. Iron is magnetically removed and.recycled.
This type of slag is produced at 48 plants and accounts for 70 percent of the
slag sold (Table 32).
78
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TABLE 32. QUANTITY OF SLAG SOLD AND VALUE (1976139
Type
Air -Coo led*
Granulated*
Expanded*
Steel making
TOTAL
# of Major
Processing
Plants
48
11
7
35
101
Millions
of Tonnes
20.8
1.5
1.4
6.0
29.7
Millions
of Dollars
59.8
3.5
6.6
9.7
79.6
Avg. Value
$/tonne
2.88
2.33
4.71
1.62
2.63
*From blast furnace (ironmaking)
Approximately 10 percent of the blast furnace slag that is produced is
landfilled; however, even in these cases it serves a constructive purpose.
For example, one major plant is using its slag as on-site fill material for
future plant expansion, but the site qualifies as a landfill due to the
various wastes (e.g., dust and oily and organic sludge) mixed in during the
dumping operation. Other plants pile the slag in mounds for future sale or
use it to dike a landfill area. Some old slag dump sites are being mined to
recover the slag to meet the increased demand.
Steelmaking slag is processed at 35 major plants but in much smaller
quantities than ironmaking slag. This slag is usually water cooled, crushed,
and iron is recovered for recycling. Steelmaking slag is sometimes recycled
to the blast furnace to recover iron, manganese, and lime values, and finds
some use in construction for unconfined bases, fill, and highway shoulders.
Its utility is much more limited than ironmaking slag because it can undergo
39
uncontrolled expansion due to hydration of free lime. It is estimated that
45 percent of the Steelmaking slag is used or recycled and that 55 percent is
landfilled. The landfilled slag often is used for dikes, landfill bases, and
for layering or mixing with dust and sludge.
Slag generation and disposition based on the national production of 125
million tonnes of steel per year is provided in Table 33 and indicates that
over 13 million tonnes per year of slag is disposed of in landfills.
79
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TABLE 33. SLAG DISPOSITION FROM 125,000,000 TONNES OF STEEL PER YEAR
(THOUSANDS OF TONNES)
Source Generated Landfilled % Recycled, Used %
Ironmaking
Steel making
TOTAL
28,300
19,360
47,660
2,800
10,560
13,350
10
55
28
25,500
8,800
34,300
90
45
72
A category for "stocked" slag was omitted due to the difficulty in deter-
mining the difference in landfilling (or dumping) and stockpiling. Many
companies that may describe the disposal site as a stockpile have accumulated
large quantities of slag over a period of years. A report prepared in 1976
for the Federal Highway Administration to examine the availability of wastes
for use as highway materials estimated the quantities available at a few slag
48
dump sites. This information is listed in Table 34 and shows that six
locations in Pennsylvania have 93.5 million tonnes (103 million tons) in slag
piles.
TABLE 34. QUANTITIES OF SLAG AT SELECTED SITES48
Company
U.S. Steel
Bethlehem
Lukens
Bethlehem
Slag Dump
Bethlehem
Kaiser
Location
Pittsburgh, PA
Bethlehem, PA
Coatesville, PA
Johnstown, PA
Vanderbilt, PA
Buffalo, NY
Fontana, CA
Slag
Type
Iron
Steel
Steel
Steel
Steel
Iron
Steel
Iron and
Quanti ty
(millions of tonnes)
40.9
18.2
12.7
4.5
13.6
3.6
4.1
Steel 18.2
7.1.2 Sludge Treatment and Disposal
Sludge is generated by water treatment facilities in which solids are
removed from process wastewater and from the water used in wet pollution
control equipment. The wastewater goes through a series of treatments that
80
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may include settlers, thickeners, oil skimmers, scale pits, polymer addition
to aid settling and dewatering, clarifiers, and filters. The type of treat-
ment is plant specific and may involve almost any combination of the above
for treating water from various processes individually or in central treatment
plants. The resulting sludge is recycled, landfilled, stocked, or put into a
lagoon for additional dewatering before disposal. The use of lagoons and
holding ponds is widespread with each major plant having at least one such
facility. A total of 16 lagoons and ponds were identified in 13 major plants,
and each plant generated some sludge that was landfilled. '
Complete sludge disposition data was available from 17 plants. This data
indicated that 13 plants practiced recycling, 10 had stockpiles on-site for
potential reuse, and all 17 landfilled at least a portion of their sludge.
The disposition of sludge is provided in Table 35 and is based on the national
production of 125 million tonnes of steel. Sludge from the rolling mills and
steelmaking furnaces accounts for 1.3 million tonnes of the estimated 1.6
million tonnes of sludge landfilled yearly.
TABLE 35. SLUDGE DISPOSITION FROM 125,000,000 TONNES OF STEEL PER YEAR16'20
(THOUSANDS OF TONNES)
Source
Ironmaking
Steelmaking
Rolling Mills
TOTAL
Generated
2,030
1,170
758
3,958
Landfilled %
270
617
730
.1,617
13
53
96
41
Stocked
190
286
476
%
9
24
12
Recycl ed
1,570
267
28
1,865
%
78
23
4
47
Some of the techniques used by individual plants are listed below to
illustrate the variety of sludge handling procedures.
Plant A - mixed with dust and slag in landfill
Plant B - spread over slag pile
Plant C - mixed with dust and scale, then stockpiled
Plant D - placed in pits in the landfill area, then covered
with slag
81
-------
Plant E - randomly dumped with organic sludge and other wastes
in a large landfill
Plant F - placed in lined landfill with leachate collection
7.1.3 Dust Treatment and Disposal
Dust is collected by dry air pollution control equipment used in the
sinter plant, blast furnace, and steelmaking furnaces. Estimates of dust
generation and disposition are given in Table 36. Sinter and blast furnace
dusts are generally recycled, but steelmaking dust is mostly landfilled and
accounts for 73 percent of the 1.2 million tonnes of dust whis is not recycled.
TABLE 36. DUST DISPOSTION FROM 125,000,000 MILLION TONNES OF STEEL PER YEAR16'20
(THOUSANDS OF TONNES)
Source
Sinter
Ironmaking
Steelmaking
TOTAL
Generated
740
1,290
1,050
3,080
Landfilled
40
170
690
900
%
6
13
66_
29
Stocked
120
190
310
%
9
10
Recycled
700
1,000
^170
1,870
%
94
78
11
61
Dust disposition data was available from 17 major plants and revealed that
16 practiced recycle, 6 had stockpiles on-site, and 7 landfilled a portion of
their dust.
Some specific dust handling techniques practiced by individual plants are
described below:
Plant G - mixed with scale and stockpiled
Plant H - mixed with water to prevent wind transportation
and placed in a holding pond
Plant I - EOF dust is recycled by using select scrap in
the BOF to keep zinc content down
Plant J - dust is "stored" in the ground by covering with
a layer of dirt
Plant K - covered with BOF slag
82
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7.1.4 Scale Treatment and Disposal
Scale is generated in the rolling operations and is usually collected
in scale pits or settling basins. These settlers serve as a preliminary
treatment of direct contact process water that is used for cooling, scale
removal, and flushing. The heavy coarse pieces settle out and the very fine
scale is removed in subsequent water treatment as a sludge.
Most of the scale generated in the rolling mills is recycled or stocked
for potential recycling. Some of the stockpiled scale is not recycled immedi-
ately due to a high oil content that causes problems of hydrocarbon emissions
and fouling of fabric filters in the sinter plant. In some cases this scale
is sent through a de-oiling process prior to delivery to the sinter plant.
Approximately 70 percent of the mill scale is recycled, 30 percent stocked,
and a small quantity is dumped (Table 37). That portion disposed of in a
landfill is generated by the cold rolling operation and has a high oil con-
tent, but it is only 0.04 percent of the mill scale produced.
TABLE 37. SCALE, DISPOSITION FROM 125,000,000 TONNES OF STEEL PER YEAR16'20
(THOUSANDS OF TONNES)
Source Generated Landfilled % Stocked % Recycled %
Soaking Pit
Rolling Mills
TOTAL
1,310
5^602
6,912
1,310
2
1,312
100
— T_,6_7_0
19 1,670
^ ^
30
34
_ •»
3JL30
3,930
•••_
ZP_
57
Soaking pit scale, also called soaking pit slag, is iron oxide scale
fused with the coke breeze or dolomite (calcium magnesium carbonate) that has
been placed in the bottom of the soaking pit. This scale may be contaminated
with refractory or other material and is usually landfilled.
7.1.5 Miscellaneous Waste Treatment and Disposal
Plant debris, trash, rubble, and refractory from relining of furnaces
are landfilled. AISI estimated that these wastes are generated at a rate of
10 percent of the steel produced (200 pounds per ton), so that the national
83
-------
production of 125 million tonnes of steel would give 12.5 million tonnes of
40
this waste. Eight plants reported to state agencies regarding the disposi-
tion of miscellaneous debris and the quantities totaled approximately 5
percent of the steel produced. In three cases the waste was disposed of by
means of contract disposal, in another three at an off-site landfill, and in
two at an on-site landfill.
Fly ash and bottom ash (or clinker) are solid wastes generated in coal-
fired boilers. In many cases the boilers are fueled with coke oven and blast
furnace gases supplemented by oil or natural gas. The use of these fuels does
not produce a solid waste. However, Dravo found that three of the ten plants
visited used one or more coal-fired boilers that generated fly ash and bottom
20
ash. Information on these wastes was obtained from state agencies for six
plants and their rate of generation was approximately 13 kg per tonne of
steel. Two of these plants landfilled the ash on-site and the other four off-
site.
Grinding and scarfing dust arises from the removal of surface defects
during the finishing operations. Battelle estimated in 1976 that there were
43 facilities with air pollution controls on these surface finishing opera-
41
tions. The quantity of dust as reported by Dravo ranged from a negligible
amount to 0.1 percent of the steel produced, and was unknown in three of the
20
six plants reporting this waste. Based on the Dravo report, the quantity of
this waste generated and landfilled is believed to be small.
Spent pickle liquor was discussed briefly in Section 6.1.7 and the sludge
20
from neutralization was estimated as 350,000 (dry) tonnes per year. An
estimated 800,000 tonnes of pickle liquor solution is generated from the over-
all production of 125 million tonnes of steel. An EPA survey revealed that
19
over 60 percent of the spent liquor was disposed of without treatment. A
change from deep-well disposal to neutralization would, therefore, cause a
significant increase in the amount of sludge that must be disposed of in
landfills. The disposal problem is complicated by the fact that hydrated
metal oxides from the neutralization process usually will not dewater to more
than 10-20 percent solids, so this sludge is not really a solid but a pseudo-
42
plastic fluid. The previously cited EPA document states that the pickling
of one million tons of steel, upon neutralization of the spent pickle liquor,
84
-------
could result in 200,000 tons of wet sludge, which would require 150 acre-feet
19
of permanent fill volume.
In Pennsylvania, most pickle liquor is handled by two contract haulers
who use the following disposal technique:
1. Pickle liquor is placed in a lagoon and neutralized;
2. The liquid is floated off and the sludge is left in place in
the unlined lagoon, and
3. When the lagoon is full, it is covered with a sloping top of
soil and revegetated.
7.2 CURRENT DISPOSAL FACILITIES
7.2.1 Prevalence of Types of Disposal Practices
Published data was reviewed and supplemented with data from state
agencies to obtain estimates of the number of disposal sites and percentages
of wastes disposed of on-site, off-site, and by contract disposal. The data
base for the prevalence of different types of sites consisted of the 13 plants
visited by Dravo and Calspan and 20 plants for which information was pro-
vided by state agencies in Pennsylvania, Indiana, Maryland, Michigan, and
Ohio. The various disposal facilities for the 33 plants included 28 on-site,
11 off-site, and 10 contract disposal sites. The total for contract disposal
does not include slag processors or those contractors handling spent pickle
liquor only.
The use of on-site landfills appears to be a function of plant location
and land availability. Many plants located in Chicago and Pittsburgh have
off-site dumps, use contract haulers, and only use available plant property
for stocking wastes for potential recovery. Plants located in Indiana,
California, Alabama, New York, and some areas of Pennsylvania take advantage
of available on-site or nearby off-site property for landfills. For example,
a company in the Pittsburgh area has one large off-site landfill serving four
plants, while in eastern Pennsylvania another extensive steelmaking complex
has five landfills on its own property.
Contract disposal is used routinely in combination with on- or off-site
disposal. Based upon a sample of 10 contract haulers, the types of wastes
eliminated via contract disposal (excluding slag, oil, pickle liquor) were:
85
-------
plant rubble, debris, miscellaneous wastes (4), sludges (4), and soaking pit
slag (2). The contractors and their locations are listed below:
Bairstol Central Teaming Co. (IL) Liquid Engineering Co. (IL)
Browning-Ferris Industries (PA) Pittsburg and Lake Erie
Cinders Co. (IL) Railroad Co. (PA)
E.C. Levy Co. (MI) Sanitary Landfill Co. (PA)
Indiana Sanitation Co. (IN) Vogel Co. (PA)
Industrial Disposal (IN)
Complete data on the quantities of waste disposed of by each method was
available for 17 plants. These quantities were summed and the percentage of
total nonhazardous waste eliminated via each of the three disposal categories
was estimated as 65 percent on-site, 29 percent off-site, and 6 percent by
contract disposal.
7.2.2 Estimate of the Number of Landfills
To estimate the number of major landfill sites, it was necessary to
establish the number of major iron and steelmaking plants. A review of the
industry revealed that there were approximately 50 plants using blast furnaces,
basic oxygen furnaces, or open hearths (often in combination with electric arc
furnaces). In addition, 13 of the 103 plants using only EAF's have capacities
exceeding 500,000 tonnes of steel per year and were arbitrarily included as
major plants. The total of 63 major plants to be used as the basis for esti-
mating the number of landfills account for more than 90 percent of steel
production.
The estimate of landfill sites for these plants included 53 on-site, 21
off-site and 19 off-site landfills belonging to contract haulers. Details of
this estimate and the data base are provided in Table 38. Disposal by con-
tractors does not include slag, pickle liquor, or waste oil processors.
The data base used for estimating the percent of total waste going to
each type of landfill was explained in Section 7.2.1 and included 17 plants
for which complete quantity and disposiation data were available.
86
-------
TABLE 38. ESTIMATE OF MAJOR LANDFILLS
No. of Major Plants
On-Site
Off -Site
TOTAL
Contract Disposal*
Data Base
33
28
11
39
10
Estimate
for Total
63
53
21
74
19
% of Total
Waste
> 90
65
29
94
6
*Excludes slag, pickle liquor, and waste oil processors
7.2.3 Present Disposal Costs
Present disposal costs of solid wastes are variable due to differences
in land and transportation costs, mode of operation, landfill size, and
quantity of waste landfilled. Some typical costs (including capital, operating,
and maintenance costs) are given in Table 39 and show a range of $0.82 to
$5.50 per tonne for most wastes.
TABLE 39. LANDFILL COSTS
Cost ($ per tonne)
Reference
Comments
0.82 - 5.50
4.40
1.10 - 5.50
1.65+pickup+trans-
portation
4.40 - 11.00
20.00 - 24.00
Mantel 1
44
A.D. Little Co.
11
Chester Engineers
45
Private contractor
45
Chester Engineers
Calspan Corp.
46
Sanitary landfill
Average of all waste
disposal
Sanitary landfill
Natural clay base
Pickle liquor by con-
tractor
Oily wastes by con-
tractor
87
Environmental
Protection Agency
Region 9
SEP 2 7 1979
wassL
-------
A private contract disposal company stated that their basic disposal
charge for material brought to their fill site (with a natural clay base) is
$1.65 per tonne ($1.50 per ton). By private contract with the steel mills,
other items are priced to include pickup, processing for scrap removal,
hauling, and dumping. These rates would be added to the basic charge and are
confidential. The charges for pickup and transportation alo'ne could double
the basic disposal charge.
A.D. Little reported an average disposal cost of $4.40 per tonne ($4.00
per ton), but noted that the costs varied significantly among the 130 steel
plants in their survey. Chester Engineers' study of wastewater residue
management in Allegheny County (PA) estimated that the cost for disposal in
landfills ranged from $1.10 per tonne for a 5,000 tonne per day operation to
$5.50 per tonne for a 60 tonne per day operation. The same study reported the
cost of pickle liquor disposal by contract hauler as $4.40-$11.00 per tonne
($0.02-$0.05 per gallon); this includes neutralization and disposal in a
45
lagoon. The costs for oily wastes handled by contract haulers is provided
for comparison and may range up to $20-$24 per tonne ($0.10-$0.12 per gal-
lon).16
In estimating present disposal costs, it is assumed that nonhazardous
wastes are disposed of in unlined landfills. Although some claim to have a
clay base, few have provisions for leachate collection. One exception that
was discovered in the survey of state solid waste agencies was in Pittsburgh,
Pennsylvania, where lined impoundment with leachate collection is required for
some nonhazardous wastes before a new landfill site is approved.
For most of the large steel companies, the on-site dumping costs are
estimated at $1.20 to $2.00 per tonne (average of $1.60) and off-site costs
are estimated at $2.00 to $3.00 per tonne (average of $2.50). Disposal at the
contractor's site was estimated at $3.30 per tonne by doubling the basic
charge of $1.65 to include pickup and transportation. Disposal of spent
liquor was estimated at $7.70 per tonne as the midrange of the values in Table
39.
An estimate of the amount of solid waste landfilled is provided in Table
17 and totaled 17.3 million tonnes of process waste and about 12.5 million
88
-------
tonnes of miscellaneous wastes to give a total of 29.8 million tonnes. A
breakdown of estimated disposal costs is provided in Table 40 by disposal
location and includes pickle liquor since this is a relatively large volume of
waste. The total cost to the industry for disposal of major solid wastes is
approximately $65 million.
TABLE 40. COST ESTIMATE OF PRESENT DISPOSAL
Quantity
Disposal Type (tonnes of millions)
Estimated Cost
($ per tonne)
Total Cost
($ millions)
On-site
Off -site
Contractor
Pickle liquor
by contractor
19.4
8.6
1.8
0.8
1.60
2.50
3.30
7.70
TOTAL
31.0
21.5
5.9
6.2
64.6
7.3 ENVIRONMENTAL AND HEALTH ASSESSMENT OF CURRENT DISPOSAL PRACTICES
Present disposal practices include recycling or reuse, stockpiling, and
landfill ing. The major impacts on the environment from the latter two methods
result from wind transportation, surface run-off, and subsurface migration of
leachate.
Wind transportation of dusts from storage piles and landfills can be
minimized by proper attention to configuration (exposed surface area), topo-
graphic location (windbreak, despressions), moisture content, and spraying
with various chemicals.* Surface run-off can likewise be controlled by proper
attention to location, climate, and method of operation. Of primary interest
in the environmental assessment of solid waste disposal is the subsurface
migration of leachate. The balance of this section will deal with leachate
52 53
characteristics and assessment with respect to criteria outlined in RCRA. '
*The method of transporting the dusts is important. Open trucks tend to
redisperse them.
89
-------
7.3.1 Mater Quality Requirements of RCRA
The major impact of RCRA on the waste disposal practices of the iron
and steel industry is the potential damage to the groundwater. Groundwater
criteria provide for the prevention of endangerment at the property boundary
of the disposal site. Endangerment is defined as the introduction of any
substance into the groundwater in such a concentration that additional treat-
ment is necessary for a current or future user of the water, or the water is
unfit in any way for human consumption.53 Maximum contaminant levels are set
forth in promulgated National Interim Primary Drinking Water Standards.
Table 41 lists various permissible criteria of selected leachate components
in drinking water. Contamination beyond these limits makes the water undesir-
able for human consumption. Organic leachate components are also of concern
because certain coke plant wastes are known to contain polycyclic aromatic
hydrocarbons. National standards for suspected carcinogens such as polycyclic
aromatic hydrocarbons have not been promulgated due to a lack of information
about health effects. Specific organic compounds which are currently moni-
tored have been selected on the basis of the likelihood of occurrence in
treated water, the toxicity data, and availability of practical analytical
methods. EPA is actively investigating suspected carcinogens and future water
standards may reflect this activity. The World Health Organization drinking
water standards permit only 0.0002 mg/£ of polynuclear aromatic hydrocarbons.55
Pennsylvania Department of Environmental Resources data indicate that from 3-
10 mg/A of oil and grease (organics) are found in the extracts of most iron
and steel wastes.
One of the major ways that RCRA serves to manage waste disposal facilities
is the elimination.of hazardous waste from the nonhazardous waste disposal
facility. Elimination of these hazardous materials from the landfill site
reduces the required treatment of the leachate and could reduce the potential
health hazard if the liner for the landfill were to fail. For these and other
reasons, one of the criteria for classification of hazardous waste is the
potential for a component to leach out in concentrations 10 times that of
drinking water standards. One major consideration for the special designation
of a waste as hazardous is to assure that such waste is delivered to a landfill
which conforms to proper management practices.
90
-------
TABLE 41. A LISTING OF PERMISSIBLE CRITERIA FOR SELECTED COMPONENTS
FflP PIIRI TT UflTFD CIIDDI TFC 54
FOR PUBLIC WATER SUPPLIES.
Constituent
Permissible Criteria (mg/£)
pH
Arsenic
Barium
Cadmium
Chromium
Fluoride
Iron (filterable)
Lead
Manganese (filterable)
Selenium
Si 1ver
Total dissolved solids
Zinc
Carbon chloroform extract
Cyanide
Oil and grease
Phenols
Mercury
6.0-8.5
0.05a
1.0a
o.oioa
0.05a
1.2 (63.9-70.6°F)
0.3
0.05a
0.05
0.01a
0.05a
500.0
5.0
0.15
0.05, 0.2
Virtually absent
0.001
0.002a
National Interim Primary Drinking Water Regulations
7.3.2 Water Extraction of Solid Waste Materials
Water extraction tests were reported by six plants to PDER (Code A, B,
E, F, G, and H) as well as from an EPA survey58 (C) and ASTM15 (D). These tests
differ from the proposed EPA Extraction Procedure in that distilled water was
used, whereas the proposed EPA procedure uses a limited amount of acetic acid
for pH control. Higher levels of heavy metals are expected from these tests
when acetic acid is used. The ASTM leachate values were reported by Enviro
Control15 with additional ASTM testing provided by AISI. Although ASTM
tested the wastes with several different types of water, only the 48 hour
-------
extraction with carbon dioxide saturated reagent water is included in this
report.
Coke plant wastes include coke breeze, tar sludges, and pitches from
various tar storage and processing operations, ammonia still lime sludge,
cooling tower sludge, and biological treatment sludge. Due to the widely
diverse processes which can be used to treat the coke by-product gases, the
number of wastes, the amounts generated, and even the composition are expected
to vary from plant to plant. In general, coke plant wastes are expected to be
hazardous with the possible exception of coke breeze. The results of the
aqueous extraction of four coke plant wastes are presented in Table 42. With
the exception of pH, the results are best expressed as the ratio of the amount
of material in the extract divided by the permissible criteria (i.e., number
of times drinking water standards). The permissible criteria used to develop
Table 42 was the largest concentration presented in Table 41 and may differ
from legal requirements. This approach is used to provide a uniform method
for assessing potential aesthetic and health impacts on the environment from
leachate, and is not used for the classification of a waste as hazardous.
The tar decanter sludge contains relatively large amounts of oil and
grease as well as phenols. Ammonia still lime sludge contains cyanides,
phenols, and may contain polycyclic aromatic hydrocarbons in concentrations
high enough to be of concern. The water extract from cooler sludge contained
relatively large amounts of oil and phenols. Some tar is also expected in the
oil from the extract. In general, coke plant waste should be given special
consideration because of the carcinogenic nature of the coke oven gas from -
which they originate and the potential of phenols and cyanides to endanger the
groundwater. Most coke plant solid wastes are hazardous and require segre-
gation from nonhazardous wastes.
Slags are the major solid waste generated by the iron and steel industry.
They are commonly used in a variety of fill applications as well as being
disposed of in landfills. The results of aqueous extraction tests for various
iron and steelmaking slags are presented in Table 43. Although the results are
generally incomplete, a number of conclusions can be drawn. The steelmaking
slags from the BOF, the open hearth, and the EAF are generally of more environ-
mental concern than the blast furnace slag. For example, the pH is much
92
-------
10
CO
TABLE 42. RESULTS OF AQUEOUS EXTRACTION TESTS OF COKE PLANT WASTES. (Results are
expressed in the amount detected divided by the permissible criteria.
No analysis designated X.)
Tar Decanter
Sludge C
A
Ammonia Still
Lime Sludge C
Cooler Sludge A
Coke Breeze, Mine
Solids
X
0.36
X
0.12
0.2
PH
(units)
8.9
7.8
11.5
6.7
10.4
Oil
1320.0
60.0
X
60.0
33.0
Phenols
5xl05
1.3xl05
2xl04
T2xl05
0.0
Cyani des
3.0
<0.04
990.0
0.2
0.0
Cd
X
<3.2
X
<4.0
0.0
Cr
<0.2
<3,7
0.4
<2.2
0.0
Pb
< 4.0
9.6
10.0
<10.2
0.0
Refuse G
-------
TABLE 43. RESULTS OF AQUEOUS EXTRACTION TESTS OF IRON AND STEEL SLAGS. (Results
are expressed 1n amount detected divided by permissible criteria; No
Material
Blast Furnace
Slag
BOF Slag
Open Hearth
Slag
EAF Slag
Source
A
9
C
b
b
b
A
E
F
C
D
D
D
C
D
D
D
C
D
D
Solids
3.7
X
X
X
3.7
X
2.2
0.3
0.7
X
X
1.4
1.3
X
X
X
3.5
X
X
0.65
Oil
20
X
X
X
X
X
27
X
30
X
X
X
X
X
X
X
X
X
X
X
Cd
<3.2
1.3
X
<1.0
<1.0
<1.0
<3.2
<2.0
0.0
X
<1.0
<1.0
X
X
<1.0
1.0
0.0
X
0.0
0.0
Cr
<3.7
0.0
<0.2
<1.2
0.6
<1.0
<3.7
<1.0
4.2
3.0
<1.0
<0.2
X
1.0
0.0-2
2.0
0.0
5.4
2.2-6.4
5.2
pH
(units)
5.0
8.8
10.6
X
11.9
10.1
12.2
12.5
9.4
12.5
9-11
9.0
12.4
12.5
X
11.0
12.5
12.4
X
11.0
Pb
<4.4
1.2
<4
1-4.6
3.6
i.o
<4.4
7.0
0.0
4.0
<0.2-1.6
1.2
X
6.0
0-3.0
3.0
0.0
8.8
0.0
0.0
Phenol
< 5
X
X
X
X
X
<23
<26
0.0
X
X
X
X
X
X
X
X
X
X
X
-------
higher for steelmaking slags than blast furnace slags. Leachate components of
possible concern are organic materials, chromium, lead, and phenols. Steel -
making slags require special consideration because of the high pH. Heavy
metal components in the leachate are a function of the acidity of the water in
contact with the slags.
Iron oxide wastes include dust and sludges from air pollution control
facilities. Some of the water extraction tests on the sludges are presented
in Table 44, and data from the dust are presented in Table 45. It is interes-
ting to note that oil and grease were found whenever the extract for oil was
examined. Relatively large amounts of phenols were found in the blast furnace
sludge and dust. The extract from BOF dust also contained phenols.
The extract from air pollution dust and sludges was examined for many of
the wastes. In each waste examined, the extract did not meet drinking water
standards when only three metals were considered. In some cases, however, the
test results were inconclusive. Based upon these data, iron and steelmaking
dust and sludges should be impounded with leachate collection wherever the
groundwater needs protection.
Additional iron and steel wastes are presented in Table 46 with the
results of the extract testing. With the possible exception of grate ash
which was incompletely tested, the extract from the wastes did not meet the
National Interim Primary Drinking Water Standards. A high level of chromium
was reported in the melt shop rubble, slab dust, mill scale, and soaking pit
slag. Relatively high levels of oil and grease were reported whenever the
extract was tested for organic extracts. The acid rinse sludge and the slab
grinder dust contained relatively high levels of phenols. For these reasons
most of the miscellaneous wastes reported in Table 46 require special impound-
ment of leachate wherever the leachate may endanger the groundwater.
7.3.3 General Information on Soil Attenuation and Leachate Movement
The previous section discussed water extraction results of steel wastes
that are used to estimate leachate composition. However, for the purpose of
assessing the impact of leachate on the environment, it is important to under-
stand the mechanisms that may alter the leachate and the factors that affect
the accurate measurement of this impact on groundwater.
95
-------
TABLE 44. RESULTS OF AQUEOUS SOLUBILITY TESTS OF IRON AND STEEL SLUDGES. (Results are expressed
Material
Blast Furnace
Sludge
EOF Sludge
Open Hearth
Sludge
EAF Sludge
Source
A
C
G
C
H
D
C
Solids
1.6
X
0.7
X
X
X
X
PH
(units)
9.5
9.5
9.6
10.4
11.0
5.4-6.9
11.5
011
67.0
X
X
X
X
X
X
Phenols
14.0
400.0
X
X
X
X
X
Cyanides
25.0
X
X
X
X
X
X
Cd
3.2
X
X
X
X
1.0
X
Cr
3.34
0.4
3.6
1.8
1.4
1.0
1880.0
Pb
4.0
4.0
X
4.0
X
1.0-2.0
40.0
UD
-------
TABLE 45. RESULTS OF AQUEOUS SOLUBILITY TESTS OF IRON AND STEEL DUSTS. (Results are expressed in
amount detected divided bv the permissible criteria. No analysis designated X.)
Material
Blast Furnace
Dust
Open Hearth
Dust
EAF Dust
BOF Dust
Precipitator
Baghouse
Source
A
C
B
D
D
B
C
G
A
A
E
D
D
D
D
Solids
X
X
X
X
19.0
X
X
15.0
8.0
10.4
0.8
X
X
6.1
X
PH
(units)
11.7
8.9
7.2
6.3-7.2
6.8
11.9
12.6
7.0
12.4
8.2
12.5
11.5-12
12.5
12.1
12.5
Oil
X
X
X
X
X
X
X
13.0
53.0
20.0
X
X
X
X
X
Phenols
250
X
X
X
X
X
X
0
28.0
40.0
X
X
X
X
X
Cyani des
<1.5
X
X
0.02-0.4
X
X
X
4.2
0.4
0.03
X
X
X
X
X
Cd
X
X
255
63-360
330
3.5
X
353
<3.2
<3.2
X
<1 .0
<1 .0
1.0
<1 .0
Cr
0.6
0.6
0.0
0-1.0
0.0
2400
6.8
25,000
<37.4
9.52
2.0
25-66.4
< 2.0
25.2
< 0.2
Pb
5.0
8.0
18.0
12-30
66.0
3.2
3000
6.0
<4.4
8.2
142
3.8-4.8
30-38
4.8
38.4
-------
oo
TABLE 46. RESULTS OF AQUEOUS SOLUBILITY TESTS OF MISCELLANEOUS IRON AND STEEL WASTES.
(Results are expressed in the amount detected divided by the permissible criteria. No
analysis designated X.\
Material
Melt Shop
Rubble
Slab Grinder
Dust
Slab Dust
Incinerator Ash
Grate Ash
Boiler Bottom
Ash
Fly Ash
Mill Scale
Soaking Pit Slag
Wastewater
Sludge
Lagoon Sludge
Hot Mill Sludge
Acid Rinse
Sludge
Source
G
G
G
G
B
D
B
D
D
G
G
C
C
G
D
C
G
Solids
0.6
0.14
1.6
0.5
X
X
X
7.7
X
X
0.37
X
X
0.20
0.1
X
X
pH
(units)
11.3
6.6
4.9
10.2
8.0
6.5
8.4
4.9
7.8
8.7
11.1
9.6
9.5
6.8
7.2
6.6
X
011
37.0
43.0
27.0
20.0
X
X
X
X
X
X
50.0
3.3
X
157.0
2.6
X
X
Phenols
0.0
150.0
0.0
0.0
X
X
X
X
X
X
0.0
X
X
0.0
X
0.0
55.0
Cyanides
0.0
0.0
0.0
0.0
X
X
X
X
X
X
0.0
X
1.9
0.0
X
0.0
0.0
Cd
0.0
0.0
4.0
0.0
0.0
X
0.0
X
<5.0
X
0.0
X
X
0.0
6.3
0.0
0.0
Cr
26.6
0.4
308.0
1.0
0.0
X
0.5
<0.2
X
34.8
0.6
1.0
28.0
2.4
<10.0
2.4
0.2
Pb
0.0
0.0
0.0
0.0
0.0
X
3.6
12.4
<6.0
0.0
0.0
<4.0
<4.0
0.0
X
0.0
0.0
-------
TABLE 46. (cont'd)
Material
Settling Basin
Sludge
Brick Bat
Material
Scrubber Slurry
Source
D
D
D
Solids
X
0.7
2.1
pH
(units)
7.3
6.4
9.24
Oil
X
X
X
Phenols
X
X
X
Cyani des
X
X
X
Cd
<1.0
X
X
Cr
<1.0
X
X
Pb
3.0
X
X
vo
-------
As leachate moves through subsurface soils, several mechanisms can affect
the nature and, consequently, the environmental impact of the leachate. One
of these is ion exchange and adsorption by clay and organic soils that may
adsorb and retain metallic ions. For example, the cations of sodium, potas-
sium, magnesium, iron, manganese, and ammonia may be attenuated by cation
exchange reactions on adsorptive surfaces in soil. Another mechanism is metal
fixation in which metal ions bind irreversibly to the soil, or substitute with
other ions of similar radii in the mineral structure. Metal cations can also
react with phosphate, carbonate, or sulfide to yield a precipitate of low
47
solubility. Heavy metals in their metallic state are generally insoluble,
but the heavy metal salts (as from electroplating or pickling), may be quite
soluble. Ammonia that is present in leachate is oxidized to nitrate under
aerobic conditions by certain bacteria and may be nitrate by the time it
reaches groundwater.
The fate of organic leachate constituents is not well documented since
few have been identified and their toxicity is unknown. Organics may come
directly from the solid waste or from decomposition products and are probably
50
subjected to adsorption and microbial degradation.
These mechanisms are described to show the fate of some leachate constitu-
ents and not as a means of groundwater protection. They are often unpredictable
in their effect, and once the soil capacity for a particular mechanism has
been exceeded, a constituent may have an unobstructed path to the groundwater.
Some other factors that affect leachate movement and consequently affect
monitoring and sampling requirements for environmental assessment are sum-
marized below:
1. Geohydrologic conditions: Under some circumstances leachate will
percolate rapidly, as through coastal plains sand, or through
channels that may have developed in limestone. In other cases, it ^g
may move only a few feet per year through soils of low permeability.
2. Climat.ic conditions: Leachate will move differently depending on
whether or not the soil is frozen, the amount of annual precipitation,
and frequency of brief periods of intense rainfall in a dry climate.
In some states with over 70 percent of the steel wastes (IL, IN, MI,
PA, OH), the annual rate of rainfall exceeds-the potential rate of
evapotranspiration by 5-20 inches per year.
100
-------
3. Disposal methods: The type of disposal method, whether lagoon,
pit, dump, or landfill and the site preparation affect the rate
of leaching.
4. Type of wastes: Some important waste types are (a) solid, sludge,
or liquid (as in a lagoon with a continuous leachate plume),
(b) organic or inorganic, and (c) water soluble or insoluble. For
those components lighter than water, placement of wells is critical
in that leachate may float on top of the zone of saturation and
move past the sample well inlet.
5. Age of site: This is relevant in that leachate percolation may
take several months to reach the groundwater.
6. Miscellaneous: Some cases may require more than the minimum of
three wells when there is more than one aquifer, or where complex
geologic or groundwater flow conditions exist. The influence of
nearby wells, changes in aquifer depth,-and groundwater velocity
also affect leachate migration and required sampling frequency.
The effects of these factors are shown graphically in Figure 18 which
illustrates the importance of locating ponds (or lagoons), streams, and under-
lying geologic structure. Climatology, surface runoff, discharge zones, and
aquifer recharge are other factors that are shown to affect the complex inter-
relationship of the hydrologic system and must be considered in locating or
evaluating landfill sites.
Figure 19 is presented to underscore the need for a scientific study of a
landfill site. The confident placement of groundwater wells (labeled GW-1,
GW-2, GW-3) may provide a false security while the. dangerous leachate plume is
moving undetected into the groundwater.
7.3.4 Groundwater Analysis From Iron and Steel Landfills
Groundwater analysis was provided to PDER by several iron and steel
companies in Pennsylvania (Table 47). When these results are compared with
the leachate from individual wastes, both the groundwater and leachate extract
contain large quantities of oil and grease. There is also close agreement in
pH since the average pH of the leachate extract differs from the groundwater
monitoring data by only 0.2 pH units. The problems with the water in meeting
drinking water standards include alkalinity (high pH), excessive dissolved
solids, and significant amounts of chromium. The overall quality of the ground-
water was difficult to assess because of the lack of testing for heavy metals
such as cadmium, and for the composition of the organic material in the extracts.
101
-------
o
r-o
£ VAPOTRANSPIRATION
WETLANDS
EVAPORATION
, , .
' ' '
'
WATER-TABLE AQUIFER
CONFINING LAYER
ARTESIAN AQUIFER
J IT
—I—, . i
Figure 18. Illustration of relationships within the hydrologic system.51
-------
GW-K
C '
to
GW-3
K.A.uiA^.'.^^'n-^ y^;. iV:**^-,'^
Rgure 19. Abandoned gravel pit with a clay layer at its base.50
-------
TABLE 47. SELECTED LEACHATE COMPONENTS IN THE GROUNDWATER OF VARIOUS IRON AND STEEL
WASTE LANDFILLS. (Results expressed in amount measured divided by permissible
criteria.* No analysis desicmated X.)
Site, Sample
Position
A.l
A.2
A,3
A,4
A, 5
A, 6
A.7
B.I
B,2
B.3
C,l
0,1
E.I
E,2
Solids
4.5
4.2
3.9
5.1
5.1
6.3
X
5.0
5.8
5.4
1.6
X
X
X
Oil
206.0
100.0
33.0
40.0
60.0
120.0
13.5
60.0
67.0
120.0
0.53
81.0
14.9
22.5
pH
(units)
7.5
7.7
10.3
7.5
7.4
7.5
X
12.3
12.3
12.1
11.4
12.2
X
X
Ammonia
0.1
0.34
0.18
0.22
0.24
0.1
X
6.4
<5.8
4.5
X
1.8
X
X
Cr
0.8
0.8
1.2
2.2
0.8
2.6
1.2
0.8
1.0
0.8
X
0.4
0.8
0.6
Mn
54.0
26.4
2.2
72.2
97.0
117.0
6.0
2.2
1.8
2.2
X
0.0
0.2
10.0
Phenols
<12.0
<13.0
<10.0
<10.0
<10.0
<13.0
X
<10.0
<30.0
<10.0
4.9
X
X
X
Cd
X
X
X
X
X
X
0.0
X
X
X
<2000
X
0.0
0.0
*This is equivalent to "number of times permissible criteria."
-------
Five water samples were obtained from two landfill sites for additional
testing. These sites are discussed in detail in Section 7.3.5 as plants A
and E. Plant A provided water (A,7) from a seepage spring that was suspected
of containing leachate from the landfill. A well located at the edge of land-
fill E and at the highest elevation in the site was sampled (E,l). A valley
well was sampled, located 250 ft below and 1600 ft south of the well, at the
edge of the site at the head of a stream (E,2). This well is also at the edge
of, and 200 ft below the top of an established slag dump. A stream which
enters the site was sampled (E,3), together with a downstream sample (E,4).
This particular stream collects the drainage from the site.
The purpose of this sampling was to obtain information concerning ground-
water pollution from iron and steel solid wastes. The state agency involved
received some information about groundwater quality at these sites. This
investigation provided a more detailed groundwater analysis, with particular
emphasis on the organic chemicals in the groundwater, and a total elemental
analysis by spark source mass spectrometery.
The water samples were subjected to a solvent extraction scheme developed
by RTI that separates the sample into six fractions: acids, bases, insolubles,
nonpolar neutrals (NPN), polar neutrals (PN)> and polynuclear aromatics (PNA).
Each of these fractions, except the insolubles, were subjected to gas chroma-
tograph, mass spectrometer analysis. This was done for each groundwater
sample.
Tables 48, 49, and 50 indicate the number of compounds found in each
fraction, the lowest and highest concentration of the individual compounds,
and the total concentration of compounds in each category. The mass spectra
of the fraction which separates the PNAs indicated that most of the components
are not PNA's.
The PNA fractions from the five water samples were subjected to a naphtha-
lene sensitized PNA fluorescence test as prescribed by EPA (Table 51). This
test is sensitive and detected low levels of PNAs in the groundwater at the
property boundary (E,l), the upstream sample (E,3), the downstream sample
(E,4), and the groundwater seepage (A,7). The upstream site (E,3) is about
1.5 KM from a very large slag dump that is the highest elevation point of the
region. Although the levels detected were reliable only within a factor of 3,
105
-------
TABLE 48. ANALYSIS OF GROUNDWATER FROM THE PROPERTY BOUNDARY (E.I)
APPROXIMATE CONCENTRATION (ppb)
Compound Category
Acid (A)
Base (B)
Polar Neutral (PN)
Nonpolar Neutrals (NPN)
Polynuclear Aroma tics (PNA)*
SAMPLE TOTAL
No. of
Components
4
5
0
15
8
Range of Single
Component
13-38
24-100
—
20-565
10-41
Total
106
284
—
1633
200
2223
*The components found in this fraction are not PNAs. They are probably NPNs.
TABLE 49. ANALYSIS OF GROUNDWATER FROM VALLEY WELL BELOW SLAG DUMP (E.2)
APPROXIMATE CONCENTRATION (ppb)
Compound Category
Acid (A)
Base (B)
Polar Neutral (PN)
Nonpolar Neutral (NPN)
Polynuclear Aromatics (PNA)*
SAMPLE TOTAL
No. of
Components
6
4
12
17
4
Range of Single
Component
29-96
30-105
35-51
16-533
7-17
Total
343
260
484
2237
48
3372
*The components found in this fraction are not PNAs. They are probably NPNs.
106
-------
TABLE 50. ANALYSIS OF SEEPAGE SPRING WATER FROM A DUMPSITE (A.7)
APPROXIMATE CONCENTRATION (ppb)
Compound Category
Acid (A)
Base (B)
Polar Neutral (PN)
Nonpolar Neutral (NPN)
Polynuclear Aromatic (PNA)*
No. of
Components
4
5
6
16
21
Range of Single
Component
40-70
17-42
6-10
18-296
13-67
Total
246
152
45
887
703
SAMPLE TOTAL 2033
*The components found in this fraction are not PNAs. They are probably NPNs.
TABLE 51. POLYNUCLEAR AROMATIC FLUORESCENCE ANALYSIS
PNA Spot PNA Sample
Sample Unsensitized Sensitized Concentration Concentration*
E,l
E,2
E,3
E,4
A,7
None
None
None
None
None
Very light
None
Very light
None
Strong
1 ng/yl
< 1 ng/yl
1 ng/yl
< 1 ng/yl
1-10 ng/yl
3 ppb
< 3 ppb
11 ppb
< 3 ppb
3-30 ppb
*GC/MS analyzed indicated no PNAs at the 10 ppb level.
the concentrations were 15 to 55 times the International Standards for Drinking
Water (PNA, 0.2 ppb).
The groundwater seepage sample from Site A contained arsenic and chromium
which were roughly equivalent to the permissible criteria of the National
Interim Primary Drinking Water Regulations. The concentrations of the other
elements in the water were either below the permissible criteria or not
covered by the regulations. The method used was spark source mass spectro-
metry which did not include mercury and indium. Table 52 lists those elements
which were found in sufficient quantities to be of some environmental concern.
107
-------
TABLE 52. WATER POLLUTANTS OF ENVIRONMENTAL CONCERN IN
GROUNDWATER SEEPAGE SITE A
CONCENTRATION, ppm (mg/A)
Component
Chromium
Arsenic
Nickel
Iron
Silver
Strontium
Zinc
Copper
Cobalt
Manganese
Potassium
Magnesium
Lithium
Seepage
0.06
0.05
0.02
0.6
0.005
0.9
0.08
0.02
0.002
0.3
>10
>10
0.04
MATEa
0.25
0.05
0.01
0.005
46
0.1
0.05
0.25
0.1
30
90
0.33
ME6b
0.05,0.05°
0.01,0.05C
0.0006
0.3C
0.005
0.027
0.02
0.01
0.0007
0.02
0.075
0.083
0.0003
aMinimum Acute Toxic Effect, water
Multimedia Environmental Goal, water
Permissible Criteria
These concentrations were generally not substantially greater than minimum
concentrations for acute toxic effects (MATE, a hazard to human health or to
ecology induced by short term exposure to emissions). All of the concentra-
tion could not be considered compatible with Multimedia Environmental Goals
(MEGs), necessary to prevent certain negative effects in the surrounding
populations or ecosystems. A similar trend was observed in the groundwater of
Company E, both under a slag dump (Table 53) and at the property boundary
(Table 54). The concentrations of manganese and lithium are great enough to
pose a potential environmental hazard under the slag dump, although they are
not present in these concentrations at the property boundary well.
Several elements were apparently added to the stream as it flowed through
Site E. Table 55 indicates that for each of the inorganic components which
were present in concentrations sufficient to be of environmental concern, the
concentration increased as it passed through the site. This was not true for
each component concentration of the stream, since the organics, silicon,
aluminum, and titanium decreased.
108
-------
TABLE 53. WATER POLLUTANTS OF ENVIRONMENTAL CONCERN DETECTED
IN A WELL AT THE BASE OF A SLAG DUMP SITE E
CONCENTRATION, ppm (mq/i)
Component
Strontium
Zinc
Nickel
Cobal t
Manganese
Potassium
Al umi num
Magnesium
Lithium
Well Water
1.0
0.06
0.008
0.004
0.5
0.09
0.06
MATE3
46
0.1
0.01
0.25
0.1
30
1
90
0.33
"MEGb
0.027
0.02,5.0C
0.0006
0.7
0.02
0.75
0.073
0.083
0.0003
Minimum Acute Toxic Effect, water
Multimedia Environmental Goal, water
cPermissible Criteria
TABLE 54. WATER POLLUTANTS OF ENVIRONMENTAL CONCERN AT THE
PROPERTY BOUNDARY OF AN IRON AND STEEL LANDFILL
SITE E
Component
Strontium
Arsenic
Zinc
Copper
Nickel
Cobal t
Iron
Titanium
Potassium
Aluminum
Magnesium
Lithium
CONCENTRATION
Well Water
0.06
0.02
0.03
0.01
0.02
0.006
0.7
0.1
2
0.2
>10
0.01
, ppm (mg/a)
MATE3
46
0.05
0.1
0.05
0.01
0.25
0.82
30
1
90
0.33
MEGb
0.027
0.01
0.02,5.0°
0.01
0.0006
0.7
0.3C
0.083
0.75
0.073
0.083
0.0003
aMinimum Acute Toxic Effect, water
Multimedia Environmental Goal, water
Permissible Criteria
109
-------
TABLE 55. A COMPARISON OF POLLUTANT LEVELS IN A STREAM FLOWING
THROUGH A LARGE IRON AND STEEL LANDFILL SITE E
CONCENTRATION, ppm (mg/i)
Component
Strontium
Selenium
Arsenic
Nickel
Cobalt
Manganese
Potassium
Al umi num
Magnesium
Lithium
Upstream
0.1
< 0.008
< 0.003
< 0.01
< 0.001
0.004
> 10
0.07
3
0.009
Downstream
1
< 0.007
< 0.02
< 0.05
< 0.03
0.5
> 10
0.09
> 10
0.6
MATE3
46
0.025
0.05
0.01
0.25
0.1
30
1
90
0.33
MEGb
0.03
0.005
0.01,0.05°
0.0006
0.0007 r
0.02,0.05°
0.075
0.073
0.083
0.0003
aMinimum Acute Toxic Effect, water
Multimedia Environmental Goal, water
cPermissible Criteria
Table 56 summarizes the environmental pollutants of concern which were
common to the five different water samples. Although the slag dump cannot be
identified as the source of the groundwater pollution at the property boundary,
those pollutants of environmental concern present in the groundwater were
detected in significantly greater concentrations downstream than upstream.
Most of the environmental pollutants of concern in Site A were also of environ-
mental concern in Site E.
In summary, the groundwater did not meet the permissible criteria (Table
41) at any of the sites, and in many cases exceeded those criteria by one to
two orders of magnitude. Special liners are required for the landfills so
that the leachate may be collected if groundwater protection is required.
7.3.5 Descriptions of Selected Steel Industry Dump Sites
This section provides descriptions of selected steel industry dumps to
provide insight into current disposal practices and the potential or proven
adverse effects on the environment. It is important to note that RCRA requires
the closing of sites classified as "open dumps" within five years of the pro-
mulgation of disposal criteria.
110
-------
TABLE 56. WATER POLLUTANTS COMMON TO FIVE WATER SAMPLES FROM TWO IRON AND
STEEL LANDFILL SITES
CONCENTRATION, ppm
Component
Strontium
Arsenic
Nickel
Cobalt
Manganese
Potassium
Lithium
Boundary
Well
Site E
0.6
0.02
0.02
0.006
0.01
2
0.01
Slag Dump
Well
Site E
1.0
0.009
0.008
0.004
0.5
>10
0.6
Upstream
Site E
0.1
0.003
0.01
0.001
0.004
>10
0.009
(mg/A)
Downstream
Site E
1
0.02
0.05
0.03
0.5
>10
0.6
Seepage
Site A
0.9
0.05
0.02
0.002
0.3
>10
0.04
Plant A operates two sites comprising over 400 acres that have been in
use for the past 40-50 years. The wastes dumped on these sites include iron
and steelmaking slags, dusts, sludges, fly ash, waste acid, coke plant tars,
oils and sludges, miscellaneous debris, and waste oils. A hydrogeologic
survey contracted for by the plant revealed serious seepage and contamination
and attributed the problem to random disposal techniques, mixing of wastes,
runoff, and rainwater leaching. The study recommended the elimination of
specific wastes, erosion control, containment structures downstream of the
seepages, and closure by revegetation. According to the contractor, the
potentially hazardous wastes which are currently deposited at the site are
blast furnace sludge (cyanide), BOF slag and ESP dust (high pH), coal fines
(ammonia, phenol), and tar decanter sludge (tar, phenol). The remaining life
of the site was estimated as five years and the state agency plans to have the
site closed as soon as an alternate site is approved.
Plant B is part of a specialty steel company that recently applied for
and received a permit to operate a lined landfill for solid waste disposal.
These wastes include incinerator ash, BOF sludge, acid rinse sludge, and hot
rolling mill sludge. The landfill is to be prepared by removal of the top-
soil, installation of a clay liner, and the addition of two feet of BOF slag
111
-------
as a leachate base. Drains and diversion channels will be constructed under
the impoundment dike, and these gravel drainage trenches will be lined with 30
mil Hypalon plastic. The leachate drainage will be collected in a Hypalon-
lined holding pond where a one day holding period will allow solids to settle
and the supernatant (overflow) will be discharged to the river. Four ground-
water monitoring wells will be installed and analyses will be reported
quarterly; the holding pond will afford an additional monitoring point before
the overflow is discharged. To meet future disposal needs, the holding pond
may be filled in with slag and sludges with drainage to the next stage holding
pond. The expected life of this site is 25 years.
Plant C has a state approved landfill which is an unlined facility that
receives primarily steelmaking slag, but small quantities of oily mill sludge,
pickle liquor sludge, water treatment sludge, and ESP dust are also dumped.
The method of operation is to mix the dust and sludge and spread this mixture
over the disposal area which is diked with slag. A hydrogeologic survey re-
vealed that water infiltrates the soil down to impermeable bedrock, then moves
downslope along the bedrock-soil interface. Surface water is collected in a
stream and moves through the base of the site into a swamp. Two water obser-
vation wells are installed, one to monitor background water at a depth of 70
feet and one down gradient at a depth of 200 feet.
It is important to note that Plant C conducted tests to demonstrate to
the state that slag effectively removed hazardous components in the sludge.
The results showed that iron, cyanide, and some phenol were removed through
multiple passages of water through a column containing five feet of slag and
one inch of sludge. No phenol was detected in the leachate after five days,
and it was presumed the phenolics were destroyed. The study also suggested
that although some of the sludge is 50 percent oil, the oil was effectively
controlled by the slag through some unknown mechanism. Their study also found
that the sludge was impervious to water, and concluded that the horizontal
layering of sludge on top of the slag would effectively prevent water passage
through the sludge and greatly reduce leaching tendencies. The company plans
to use the permitted area for solid waste disposal for the next 50 years.
An important environmental aspect of steel industry dump sites is the
presence of deep mines in the major steel producing states of Pennsylvania,
112
-------
Ohio, Indiana, and Illinois. Exposed pyrite (FeSg) in these mines oxidizes to
sulfuric acid and can yield mine drainings with a pH less than 2 which can
compound disposal monitoring problems. For example, Plant D has been dumping
dusts, slag, sludges, and pickle liquor along a four mile stretch of their own
property. Sludges are presently put into pits, but this procedure is being
used without a state permit. The serious leaching problems that exist, are
complicated by leaching coal refuse and acidic mine drainings in the area.
Company E is in the process of fulfilling state requirements to continue
operation of a large dump site that has received steel wastes for about 75
years. Presently blast furnace slag, BOF sludge, EAF and OH dust, and fly ash
are being deposited, and in the future, water treatment plant sludges will be
landfilled. Plans include lined impoundment at an elevated location for these
sludges which are composed primarily of oil, grease, and finely divided mill
scale. Impoundment for other wastes were constructed in ravines by diking the
lower ends of the ravines to prevent flow. A basin lined with bituminous
material was constructed and used for ferro-manganese furnace fines.
An extensive hydrogeologic survey was conducted for this 500 acre site
and revealed some of the following characteristics:
1. Several springs, swamps, and streams were identified.
2. Surface and deep mines and mining spoils were located.
(The area underneath had been mined out and abandoned.)
3. The depth to groundwater ranged from 0 feet (springs)
to 48.5 feet.
4. Major groundwater flow is through permeable sandstone
and open joints.
5. Groundwater samples contained sulfate, aluminum, iron,
phenol, manganese, and cyanide.
The life of this site is estimated at 50 years.
Plant F is currently disposing of wastes by filling in a lake bordering
their property, and then using that area for plant expansion. Blast furnace
slag is the major waste deposited, but miscellaneous dusts and sludges are
mixed in and used for fill material. A permeable barrier of blast furnace
slag with steel supports and concrete cap extends into the lake to mark the
future limits of the fill area. The company plans to use the 300 acres of
113
-------
lake between the fill and barrier as their solid waste disposal site for the
next 20 years. This procedure is not environmentally sound based on RCRA
criteria for solid waste disposal, since the criteria require the prevention
of direct discharges into surface waters of unchanneled leachate seepage, when
possible.
7.4 IMPACT OF SECTION 4004 RCRA CRITERIA
The Resource Conservation and Recovery Act provides for the promulgation
of regulations for the criteria for determining which facilities shall be
classified as sanitary landfills and which shall be classified as open dumps.
The general current practice in the iron and steel industry is the dumping of
wastes in unlined sites. The major impact of Section 4004 is to require the
disposer to control the leachate migrating toward the groundwater.
All steel plant waste, with the possible exception of bricks, rubble, and
certain trash items are anticipated to have leachate which is unfit for human
consumption. Contaminants such as oil and grease, dissolved solids, fluorine,
chromium, manganese, lead, iron, phenol, cyanide, cadmium, zinc, and mercury
have been identified in some of the various iron and steel wastes at concen-
trations greater than the permissible criteria.
Although most steel plant wastes are not classified as hazardous, avail-
able leachate and/or water extraction test data have shown the extract to be
unfit for human consumption. In view of these facts and in evaluation of
environmental endangerment, a lined landfill would be required for these
wastes. However, hazardous wastes are specifically excluded from landfill
under Section 4004, since they are regulated under Subtitle C of RCRA. A
major economic impact may result if contaminants must be removed from the
collected leachate. The leachate disposal method assumed for nonhazardous
wastes is controlled discharge to waterways or recycle back through the land-
fill.
Discarded steelmaking slag would need liners because of the high pH of
the water extract, the dissolved solids in the extract, and the organic
compounds as well as inorganic elements. However, the slag does not require
lined landfill ing if it is used as a salable product, for resource recovery,
or if the state has exempted the disposal area from groundwater requirements
114
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under Case 2 of the proposed rules. Since steelmaking slags are a major
landfilled waste, two calculations were performed on the economic impact of
the proposed criteria with and without the required lined landfill ing of steel
slag.
The impact of Section 4004 on the iron and steel industry was calculated
assuming the following: the criteria requires the lined landfilling of certain
wastes, the removal of the leachate resulting from rainfall on these wastes,
and the controlled discharge of the water which is collected. Therefore, the
cost of the criteria would be the cost of converting an existing landfill into
an area for the collection and removal of leachate and would require a sub-
stantial capital investment. The criteria do not specifically require changes
in current solid waste disposal practices such as the transportation of wastes,
employment of landfill personnel, or purchase of land for waste disposal. It
should be pointed out that the costs of Section 4004 do not include those
costs incurred as a result of hazardous waste disposal, which may be more
expensive than for nonhazardous wastes.
The estimated annual capital cost for lining nonhazardous waste landfills
is $6.9 million (Table 57). The cost of a lined landfill for steel slag dis-
posal is approximately twice that of nonslag nonhazardous waste disposal.
Although some economies of scale are achieved with increasing waste disposal
volume, when steel slag is placed in a lined landfill, the overall cost is
still three times as high. The estimated cost is relatively low for two major
reasons. One primary consideration is that only the cost of converting a
potential landfill site to a lined landfill was considered. The second major
factor is that the majority of iron and steel wastes are currently either
recycled, sold, or used in a manner consistent with the objectives of RCRA.
TABLE 57. SUMMARY OF ESTIMATED 4004 CRITERIA COSTS
Enforcement
A-Steel Slags
Excluded
B-Steel Slags
Annual
Capital
Cost
($ Millions)
6.9
21.1
% Current
Environ-
mental
Costs
0.63
1.9
% Future
Environ-
mental
Costs
0.2
0.6
% of
Sales
0.01
0.04
% of
Current
Disposal
Costs
12
38
Included
-------
When the estimated implementation costs of Section 4004 are compared with
other costs in the industry, it is apparent that those costs would not be a
significant factor in the compliance ability of the industry. .This cost is
also relatively low in comparison to either the current or projected environ-
mental costs and extremely small when compared to the percent of sales. On
this basis it is expected that the criteria will have little impact on either
the cost of products or the economics of production.
Current disposal costs are estimated for 30 million tonnes of nonhazardous
waste at an average cost of $1.90 per tonne or $58 million. As Table 57
shows, this represents a small fraction of current and future environmental
costs. Current annual environmental operating costs were estimated as $8 per
59
ton of ste,el, including the cost of air and water pollution control. The
long term environmental costs, including disposal of nonhazardous solid waste,
are estimated as $3,620 million per year. This estimate is consistent with
the Council on Wage and Price Stability's estimate of $18-33 per ton.
Section 4004 will, however, have a major impact on the disposal practices
used by the industry and substantially increase the cost of present land
disposal systems. It is estimated that the capital costs for developing
leachate collection facilities alone will double the disposal costs of those
wastes placed in lined landfills.
7.4.1 Landfill Site Monitoring for Enforcement of Groundwater Standards
The cost of enforcement monitoring for groundwater contamination will
50
range from several thousand dollars to several tens of thousands of dollars,
and will be higher than for assessment monitoring. One of the reasons for
this is that quantitative data will be necessary regarding leachate contam-
ination at a landfill site. There must be sufficient evidence to prove beyond
any reasonable doubt that the contamination exceeds applicable standards and
that this excess is caused by the land disposal site. This wide range of
possible costs is due to the differences in site conditions and state laws.
Monitoring for zero discharge laws requires sampling devices immediately
adjacent to the downgradient landfill edge or beneath the site whereas more
costly monitoring would be involved in cases concerning property line laws.
In these cases, several monitoring wells at various distances and depths
116
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downgradient as well as comprehensive surveys, especially depth to ground-
water, will directly affect the installation costs of sampling devices.
The proposed EPA rules state that as long as leachate may enter ground-
water in such quantities and concentrations that the groundwater quality may
be endangered, monitoring of groundwater, prediction of leachate migration,
and a current and acceptable contingency plan for corrective action are re-
quired. The prediction of leachate migration can be determined only by
interpretative monitoring which differs from detective monitoring which only
establishes the presence or absence of contaminants. Interpretative
monitoring determines the extent of damage by leachate and prescribes remedial
action.
A major limitation to monitoring and characterizing the nature of the
groundwater pollution lies in the nature of the plume itself. The pollutants
which leach out in different parts of the landfill may have different impacts
on the groundwater quality. Due to the nature of the formation of the plume,
there is severely limited radial mixing. Thus, there may be a wide range of
unpredictable variations in contaminant concentrations within a plume of
leachate-enriched groundwater.
A number of factors serve to complicate the prediction of leachate migra-
tion. Wide variations have been observed in leachate concentrations over
short distances and time periods and sampling at additional points implies the
installation of additional monitoring wells. Before installation can take
place, however, determination of the flow rate and groundwater direction are
prerequisites. Because groundwater flow rates are slow, data must be col-
lected over long periods of time in order to perform a comprehensive analysis
of the landfill. Conditions such as fractured rock are so unpredictable as to
frustrate an intensive monitoring effort. As a result, interpretative
monitoring which determines the extent of damage and prescribes remedial
action is not considered practical for every disposal facility. Detective
monitoring, however, can be useful to establish the presence of contaminants.
The technique will establish the need for additional monitoring if necessary
and a plan for remedial action.
A minimally acceptable monitoring well network should consist of the
following: one line of three wells downgradient from the landfills pene-
trating the entire saturated thickness of the aquifer, one well immediately
117
-------
adjacent to the downgradient edge of the field area screened so that it inter-
cepts the water table, and one well completed in an area upgradient from the
landfill so that it will not be affected by potential leachate migration.
Every effort should be made to have a minimum of five wells at each landfill
and no less than one downgradient well for every 76 meters of landfill
frontage.
Even if wells are sited according to the background information described
here there is a high probability that one or more of them will not intercept
the plume of leachate-enriched groundwater due to the anisotropic nature of
the aquifer material. Also, the operation of the landfill can significantly
influence concentrations of pollutants observed in the monitoring wells since
the location of a pollutant in the landfill determines the location of the
leachate from that waste in the overall leachate plume. Depending upon the
hydrogeological nature of the landfill site, the leachate plume may be con-
fined to the landfill site or it may travel long distances. Also the plume
may divide into multiples, move into different aquifers or reverse its direc-
50
tion. If the monitoring program is to be effective, it must account for all
possible leachate movement.
When monitoring is to be used as an early warning system, sampling in the
zone of aeration is desirable. This type of monitoring is most appropriately
done directly beneath the landfill where the leachate is migrating downward to
the water table. The devices to be used should be in place before construction
of the impoundment facility thus avoiding the possibility of creating other
potential leakage sources by drilling through the landfill. Pressure vacuum
lysimeters are used to monitor the zone of aeration. Some of the advantages
of this device are that it is inexpensive, reliable, and standard water analyses
can be made.
Table 58 presents various cost factors for surveying and monitoring a
typical two acre landfill site. Although the cost of a hydrogeological survey
would be dependent upon location, typical costs might be $13,000 per site.
This cost does not include the cost of locating a suitable site. The place-
ment of three five-well clusters with a 1.5 meter screen in each well and four
lysimeters in the zone of aeration under the landfill is estimated to cost an
118
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TABLE 58. COST FACTORS FOR SURVEYING AND MONITORING
A TYPICAL TWO ACRE SITE
Cost ($)
Location, mapping, surveya 2,000
Soil studya 1,400
Geology (4 borings)3 4,200
Hydrology (4 wells)3 3,800
Flooding, Climatology3 600
Discharge to groundwater survey3 1,200
(6 sets of analyses)
Monitoring Wells (3) 5 well cluster 9,200
1.5 meter screen
j»»
Lysimeters (4) installed under the 1,300
landfill
TOTAL 24,300
3Green Engineering, Pittsburgh, PA, 197860
EPA Procedures Manual, inflated at 10 percent per year to 1978
CRTI estimate, 1978
additional $10,000. This brings the total estimated cost for surveying and
monitoring to $24,300. An additional $3,000 is estimated to be required
annually for quarterly water analyses. This cost as well as the expense of
obtaining the samples to be analyzed should be considered an operating
expense. Therefore, the total cost to the industry for Section 4004 would be
the capital plus operating costs.
The cost of the hydrogeological survey and well installation is a capital
expense and is included in the cost of the facility. Twenty percent of the
excavation and grading costs is allocated for the survey and wells. For the
model plant of 2.5 million tonnes of steel per year, the 20 percent survey
allocation would be $27,000 for a landfill holding one year of waste produc-
tion. For an average sized EAF plant of 600,000 tons per year, the development
of a 3 year disposal facility would result in an allocation of $24,000.
Therefore, this 20 percent estimates the survey and monitoring well expenses
and represents about 20 cents per cubic meter of solid waste.
119
-------
Within the accuracy of the expected capital costs, the estimated $3,000
annual analytical costs are not expected to be a significant contribution and,
therefore, are not included in the economic analysis. The analytical costs
become a significant aspect of overall landfill costs if the key indicators
demonstrate a potential problem with groundwater quality. If this is the
case, then more extensive testing would be required and its cost would be
dependent upon state regulations. With iron and steel wastes, some of the
leachate constituents of interest are as follows:
1. Lead
2. Chromi urn
3. Cadmi urn
4. Oil and Grease
5. Polycyclic Organic Materials
6. Benzo(a)pyrene
7. Cyanide
8. Phenols
9. Mercury
These constituents are some of those found in iron and steel wastes; the
National Interim Primary Drinking Water Standards, however, do not as yet
include polycyclic organic materials or benzo(a)pyrene.
7.4.2 Model Facility
The cost of lining solid waste landfills has been developed by con-
sidering the development costs for a model facility. The overall operating
costs of a landfill include land, labor, earthmoving equipment and trucks,
lining, groundwater monitoring, as well as other factors.
A major cost component is the development of those lined landfill facili-
ties which will be required to eliminate leachate endangerment to the environ-
ment. The approach taken has been to isolate the actual costs of converting
an existing landfill into a site providing for the collection and removal of
leachate. Figure 20 is a sketch of a model facility with leachate control.
The facility, however, is not to be confused with the recommended or required
method of leachate control and is presented only to provide an order of magni-
tude estimate of lined landfill costs.
The model facility is lined with 0.6 meters of clay and sealed with
bentonite. A drainage system is installed in the bottom of the facility and
120
-------
"^ S^^g^^
GRAVEL
DRAIN SYSTEM
Figure 20. Diagram of a sanitary landfill with leachate collection.
-------
covered with gravel for drainage and protection of the pipes. The type of
drainage system used would depend on the nature of the wastes. For example,
water entering an impoundment facility storing coke tar collects on the
surface of the tar. In many cases slag could be used in place of gravel,
reducing the cost. The water drains to a concrete sump and is pumped out.
Leachate treatment is not considered in this analysis, only controlled
discharge in an environmentally acceptable manner. If the leachate were
hazardous, the wastes would not be subject to the proposed criteria but would
be subject to Subtitle C "Hazardous Waste Management." It is both conceivable
and probable that the annual cost of treating the Teachate may exceed the annual
cost of constructing an environmentally acceptable lined landfill facility.
In the Figure, excavated earth was used to form peripheral dikes, in-
creasing the potential landfill volume. The leachate collection drains were
assumed to be placed at 2 meter intervals with two major collection drains
crossing the length' of the landfill. A fixed cost for the sump and pump was
established as $4,340. Landfill facilities which would require a more
effective pump are considered to cost enough so that upgrading of the pump
would add little to the overall cost.
The excavation cost was based on the concept of moving earth from the
trench to form dikes which double the storage volume of the trench and have a
26.5° slope. The height of the dike would be as deep as the excavation trench
for the large volume landfills of interest. For example, a small EAF plant
producing 200,000 tonnes of steel per year could be expected to generate 2,500
m of waste per year. An impoundment volume large enough to store 10 years
supply of waste would contain 25,000 m . The dimensions of the impoundment
facility could be 10 meters deep, 80 meters long, and 40 meters wide. Ex-
cavated earth from a 5 meter deep trench would provide enough material to
build a 26.6° dike and cover the filled site.
After the trench is dug, clay liner is installed at an estimated $2 per
cubic meter and compacted. Then a bentonite layer is mixed with the surface of
the clay. The piping is positioned in the bottom of the trench and covered
with gravel. Additional gravel is used on one end of the trench. With the de-
velopment of the model lined landfill costs as a function of the dimensions of
122
-------
the landfill, the costs were calculated for a variety of landfill sizes. The
shape of the landfills were selected as 4:2:0.5, the length to width to depth
ratio. Eight different sized landfills were selected for this same shape.
The results are presented in Table 59.
i
TABLE 59. THE COST OF LANDFILL LINERS FOR VARIOUS SIZED LANDFILLS
(L:W:D) = (4:2:0.5)
Volume Cost/Volume
Cubic Meters Cost ($) ($/Cubic Meter)
256
864
4,000
13,500
32,000
108,000
500,000
1 ,688,000
11,500
15,900
31,700
67,600
126,000
328,000
1,208,000
3,584,000
45.0
18.4
7.91
5.0
3.93
3.04
2.41
2.12
The cost of the larger landfill is expected to be somewhat higher than
the model indicates due to the somewhat excessive depths obtained with a LWD
ratio of 4:2:0.5. The disposal of dusts and sludges could be impractical in
depths of 25 meters unless special techniques were used. Steel slags could be
used as intermediate cell cover, for example.
Table 60 presents several estimates for operating a facility with leachate
impoundment. The cost of impounding metallurgical solid wastes was estimated
by Agarwal, et al. A square pond was formed on level land by earthen dikes
and PVC sheet. The expenses for developing a storage pond in a canyon or
ravine surrounded by a large earthen dam were expected to be substantially
less than costs for level land. The .typical integrated iron and steel plant
generates 36,000 metric tons of nonhazardous solid wastes. Bricks and rubble,
as well as slag are not considered in the landfilled wastes. A 180,000 m
impoundment lagoon that provides for 5 years' waste production was estimated
as costing $250,000. The annual cost of financing the project at 12 percent
123
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TABLE 60. LANDFILL COSTS FOR NONHAZARDOUS WASTE LEACHATE COLLECTION
AND REMOVAL. (Generated In the Model Plant, dollars per
metric ton, 2.5 Megatonne production, specific gravity
of waste-2.0)
Reference $/Metric Ton
Calspan, operation costs3 7.5
Arthur D. Little, Inc., operation costs 10.0
RTI, impoundment costs only0 1.9
RTI, pond impoundment costs only 1.46
Calspan, impoundment costs only 1.6
aAnnual impoundment and waste segregation is considered, as well as
the cost of hauling, labor, etc.
Based on contract hauling costs.
cCost of converting an existing site for sanitary landfill leachate
collection and removal.
Difference in landfill cost due to impoundment, excavation excluded.
interest is $69,000. The cost per metric ton, with a specific gravity of 2.0,
is $0.96. This cost is based on 1973 dollars and was estimated as $1.46 per
tonne in 1977 dollars using a 10 percent inflation rate. The cost estimate for
the lagoon is provided for comparison with the cost of the model facility.
RTI's estimate of the lined landfills costs for the model plant was based
on the estimated cost of a model facility (Table 61). Clay is assumed to be
available on site, and the costs of the other components include transportation
costs. Bentonite is used in addition to the clay to provide additional pro-
tection. Special earth additives may be required to reduce the permeability of
the compacted earth in many sites. The component costs are expected to be site
specific because of transportation costs and local availability.
The cost per volume as a function of volume was used to prepare Figure 21.
Although the economics are expected to be very sensitive to the volume, it is
relatively insensitive for the large landfill volumes.
The expense of developing a lined sanitary landfill is a capital expense.
However, if a landfill facility is developed each year, it could be considered
124
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TABLE 61. COST FACTORS FOR THE MODEL IMPOUNDMENT FACILITY
1. Excavation3 2(LWD/2)e
2. Grading3 0.4 (LW-2 DW-2 DL+D2)
3. Survey and Testing3 2Q% of (1) + (2)
4. Clay Baseb (2.0)(0.61)(LW+2.47 DW+2.47 DL+4D2)
5. Bentonite Surface Layer3'0 1.8 (LW+2.47 WD+2.47 DL+4D2)
6. Drains3 6.00 (2L-4D+0.5 LW+2D2-LD-WD)
7. Graveld 9.10 (0.61 LW+0.15 WD-1.22 DL+2.44D2)
8. Bentonite Cover3'0 1.8 (LW+2DW+2DL+4D2)
9. Earth Coverb 0.4 (LW+2DW+2DL+4D2)
10. Concrete Sump 2,340
11. Pump 2,000
12. Electrical, pump piping, etc. 2,000
13. Contingency 30% of the above
3Calspan Building Construction Cost Data 1978
b e
RTI L,W,D are the average length, width, and depth
°EPA^2 1n me^ers*
an annual cost. If a facility is built and financed which can be used for the
disposal of 10 years waste, then the annual cost is the cost of the repayment
of principal plus interest. This method permits the producers of relatively
small volumes of waste to take advantage of some of the economies of scale
evident in Figure 21. A disadvantage to lining a large area is that a
plant is paying for disposal volume which is not used in the immediate future.
Thus, there is a "trade-off" between the additional cost of a small facility
and the additional interest charges from a large facility. Figure 22 presents
optimization curves for three different sizes of plants: a small (1,000
3 3
m of waste per year waste), medium (10,000 m of waste per year), and large
2
steel plant (50,000 m per year). The small plant has an optimum landfill
size equivalent to 5-10 years waste production but the medium and large steel
plants economically operate with landfills sized for 2-5 years production.
The values obtained for the optimum costs in Figure 22 are plotted in Figure
23. This relationship is used to develop the industry's cost for compliance
with RCRA Section 4004.
125
-------
ro
en
Volume of Landfill
(Cubic Meters x 1000)
Figure 21. Cost factors for various landfill sizes.
-------
o
(O
15
ro
3 J-
O O)
Q.4J
O •«-
J3
+J 3
V) t_>
r— Q.
fO
4-> I/)
•r- S~
O.
-------
INJ
00
•3:8
•r—
D. O
fO •!-
O JO
o
4-> OJ
(/) O.
o
O V)
r— JO
fO r—
3 r—
C O
10
10
30
60
100
Annual Waste Generation
(Cubic Meters x 1000)
for various rates of waste generation.
-------
The steel industry is divided into two types of plants, (1) facilities
comprised of relatively small EAF's and (2) facilities containing large blast
furnaces, BOF's, and open hearth furnace plants. For each of these types, the
total production was divided into tenths and a cost figure, using Figures 21
and 23, was developed for a typical plant in each production division.
Summation of the individual costs provided the estimate of the cost to the
industry. Table 62 summarizes the costs for the segments of the two plant
types.
The annual capital cost for converting landfills from open dumps to
lined landfill sites is estimated to be $6.92 million. This represents 0.014
percent of the selling price of steel (6 company average, $397.77 per ton in
1977). This amount is not expected to have a significant economic impact on
the steel industry; however, this impact could be severe for contract haulers,
especially considering the required capital investments in Table 59.
Table 63 summarizes the cost of capital needed to develop larger sanitary
landfill sites for slag. A typical integrated iron and steel plant would
require approximately $400,000 per year to line steelmaking slag and other
nonhazardous wastes landfills. This figure represents a cost of $0.16 per ton
of steel. Tables 64 and 65 summarize landfill facility costs in view of the
current practice of discarding half of the steelmaking slag and the annual
landfill cost when this slag is excluded.
The estimated annual capital cost for steelmaking slag that is currently
landfilled is $14 million, increasing the annual capital cost of landfill
facilities threefold. The estimated annual cost for landfill ing all wastes,
excluding bricks, rubble, trash and blast furnace slag is $21 million. This
figure represents 0.042 percent of the selling price of steel. If steelmaking
slag is discarded rather than used as a product, then it should be disposed of
in a sanitary landfill.
The economic impact is also contingent upon the regulations developed to
control hazardous and nonhazardous wastes. For example, a state may declare an
aquifer under a nonhazardous waste landfill for use other than as a drinking
^ater supply per Section 257.3-3(b) (1) of RCRA. In this case, there would be
129
-------
00
o
TABLE 62. CAPITAL COST TO LINE LANDFILLS FOR VARIOUS PRODUCTION SEGMENTS OF THE'
IRON AND STEEL INDUSTRY.* (The Industry 1s divided Into tenths by the
amount of steel oroduced for two tvoes of olants.)
Cumulative Fraction
of Production
0.1
0.2
0.3
0,4
0.5
0.6
0.7
0.8
0.9
1.0
Average Costs ($/m )
Average Costs ($/tonne)
(S.G. = 2.0)
EAF
Plant Size
(1000 Tonne
of Steel /Yr)
0-160
160-250
250-350
350-450
450-600
600-750
750-1000
1000-1200
1200-1500
1500-
Only
Landfill
$/m3
8.4
6.4
5.8
5.4
5.1
4.8
4.6
4.4
4.3
4.2
5.34
2.67
Plants with BF,
Plant Size
(1000 Tonne
of Steel /Yr)
0-1600
1600-2300
2300-2500
2500-3000
3000-3500
3500-4000
4000-4750
4750-5700
5700-7200
7200-
BOF, OH
Landfill
$/m3
4.2
4.0
3.8
3.7
3.6
3.5
3.4
3.3
3.2
3.1
3.58
1.79
*Steelmaking Slags Excluded
-------
TABLE 63. CAPITAL COST TO LINE LANDFILLS FOR VARIOUS PRODUCTION SEGMENTS OF THE
IRON AND STEEL INDUSTRY.* (The Industry 1s divided Into tenths by the
amount of steel produced for two types of plants.)
Cumulative Fraction
of Production
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
o
Average Costs ($/m )
Average Costs ($/tonne)
(S.G. = 2.0)
EAF
Plant Size
(1000 Tonne
of Steel/Yr)
0-160
160-250
250-350
350-450
450-600
600-750
750-1000
1000-1200
1200-1500
1500-
ONLY
Landfjll
$/m
5.1
4.4
4.2
3.9
3.8
3.6
3.4
3.3
3.2
3.1
3.84
1.93
Plants with BF,
Plant Size
(1000 Tonne
of Steel/Yr)
0-1600
1600-2300
2300-2500
2500-3000
3000-3500
3500-4000
4000-4750
4750-5700
5700-7200
7200-
BOF, OH
Landfill
$/m
3.3
3.1
2.9
2.8
2.7
2.6
2.5
2.5
2.5
2.4
2.74
1.37
*Steelmaking Slags Excluded
-------
TABLE 64. A SUMMARY OF THE YEARLY CAPITAL COST TO CONSTRUCT LINED LANDFILL
FACILITIES FOR IRON AND STEEL WASTES.* (Steelmaking Slags
Excluded.)
Quantity Steel
(106 Mg/Yr)
EAF Only Plants 24.2
OH, BOF Plants 100.8
All Iron and 125.0
Plants
Quantity Waste Costs
(106 Mg/Yr) ($/Mg) ($ x 106)
0.621 2.67
2.94 1.78
3.55 1.94
1.66
5.26
6.92
*Principal + financing costs
TABLE 65. A SUMMARY OF THE YEARLY CAPITAL COSTS TO CONSTRUCT LINED LANDFILL
FACILITIES FOR IRON AND STEEL WASTES.* (Steelmaking Slags
Excluded.
EAF Only Plants
OH, BOF Plants
All Iron and
Steel Plants
Quantity Steel
(106 Mg/Yr)
24.2
100.8
125.0
Quantity Waste
(106 Mg/Yr)
3.171
10.94
14.11
Costs
($/Mg) ($
1.93
1.37
1.50
x 106)
6.12
15.0
21.1
*Principal + financing costs
132
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no economic impact from Section 4004. However, another state could require an
artificial liner, multiple liners for contingency purposes, monitoring of
groundwater movement near the site, and leachate treatment facilities. These
requirements could pose a significant impact, particularly on a smaller plant.
7.5 ALTERNATIVE DISPOSAL PRACTICES FOR THE IRON AND STEEL INDUSTRY
The Resource Conservation and Recovery Act provides for the promulgation
of regulatory criteria for determining which facilities shall be classified as
sanitary landfills and which shall be classified as open dumps. Any manage-
ment practice which constitutes the open dumping of solid waste is prohibited,
and all open dumps will be either closed or upgraded to meet the criteria of
52
Section 4004 with an acceptable timetable for compliance. The criteria
provide that a facility is classified as a sanitary landfill and not an open
dump only if there is no reasonable probability of adverse effects on health
safety, or the environment, and if it is located, designated, constructed,
52 53
operated, completed, and maintained as prescribed by the criteria. '
The major adverse effect is groundwater contamination. The law provides
protection through the requirements that the landfill not make the water unfit
for human consumption, that the groundwater user does not need to increase
water treatment before use, and that it is unnecessary for a future user to
53
use more extensive water treatment than would otherwise be necessary.
One method of preventing groundwater endangerment is to use the site's
natural hydrogeologic conditions and soil attenuation mechanisms. However,
soil attenuation alone may not provide definite assurance of the quality of
the leachate plume from iron and steel wastes. The other technique for
preventing endangerment of the groundwater is the collection of leachate
through the use of artificial liners where the leachate is removed, recircu-
53
lated, or treated as appropriate.
A state may designate a groundwater source for use other than as a human
drinking water supply if it is impractical for use as such or if alternative
53
drinking water supplies are available. Under these circumstances, the
waters of an adjacent state or county must not be endangered by the landfill.
When a groundwater source is designated for another use, the state may specify
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what groundwater quality must be obtained at the disposal site's property
boundary. This special designation could be useful in situations where a
state wishes to maintain an existing landfill, when artificial liners would
serve no useful purpose, or in site specific cases when the nature of the
waste and the landfill location is neither a danger to the environment nor
expected to contaminate wells.
One type of special use of iron and steel wastes is land modification and
improvement by selected landfill ing. There are examples of iron and steel
plants increasing their size through such operations. States could permit the
regulated use of these wastes for land reclamation by special groundwater
source designations.
7.5.1 Sole Source Aquifers
The location of sole source aquifers must be considered when examining
alternative disposal practices. Section 1424(e) of the 1974 Safe Drinking
Water Act makes it possible for EPA to designate areas which are principally
dependent upon an aquifer for drinking water supply. Aquifers are geological
formations which yield significant quantities of water to wells or springs.
They are replenished through recharge zones which permit rainfall and surface
runoff to enter the aquifer. In the recharge zone, the aquifer is especially
sensitive to contamination from a disposal site. Disposal sites should not be
located in the recharge zones of sole source aquifers when feasible alterna-
tives exist. The feasibility of the alternative site is to be determined by
technological and economic factors. When a landfill is to be permitted in the
recharge zone of the sole source aquifer, special precautions must be taken so
that it is located, designed, constructed, operated, maintained, and monitored
to prevent endangerment to the aquifer.
7.5.2 Waste Separation
The separation of hazardous and nonhazardous wastes should also be
considered when evaluating alternative disposal practices. The ma'jor effect
of RCRA on current iron and steel mill waste disposal practices is the isola-
tion of hazardous waste material. These wastes, are not to be placed in a
sanitary landfill but in special lined hazardous waste landfills. Removing
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the hazardous materials from the sanitary landfill reduces significantly the
probability of environmental damage. The leachate which is collected from the
nonhazardous waste material is less than 10 times the drinking water standards
for many of the criteria pollutants. Although this level of environmental
pollutants does not guarantee the controlled discharge into streams under an
NDPES permit, in some cases the dilution factor would be sufficiently great
for the collected leachate to be directly discharged into surface water
systems.
The hazardous waste materials produced by iron and steel mills include
some of the coke plant wastes, ferromanganese blast furnace dust and sludge,
EAF dust and sludge, and selected steel finishing wastes. The steel plant
wastes published in the proposed hazardous waste regulations are presented in
Table 66.
TABLE 66. OFFICE OF SOLID WASTE LIST OF HAZARDOUS IRON AND STEEL WASTES
Coking Decanter tank tar, toxic, organic.
Decanter tank pitch sludge, toxic, organic.
Oleum wash waste, corrosive. Caustic
neutralization waste, corrosive. Ammonia
still lime sludge, toxic.
Ironmaking Ferromanganese blast furnace dust, toxic,
reactive. Ferromanganese blast furnace
sludge, toxic. EAF dust, toxic. EAF
sludge, toxic.
Steel Finishing Alkaline cleaning waste, corrosive. Waste
pickle liquor, corrosive. Cyanide bearing
wastes from electrolytic coating, toxic.
Chromate and dichromate wastes from chemical
treatment, toxic.
A hazardous waste is hazardous because of its inherent characteristics.
Current EPA characteristics for the classification of hazardous wastes are
ignitability, corrosivity, reactivity, and toxicity. Additional waste may
be classified as hazardous when other criteria, such as mutagenicity, are
developed.
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7.5.3 Artificial Liners
Leachate is formed by water infiltrating a landfilled waste. The
leachate migrates through the soils under the solid waste and is attenuated by
ionic change, filtration, adsorption, complexing, precipitation, and bio-
64
gradation. If the voids in the soil are filled with water, the leachate
moves to the groundwater where there is little dilution unless a natural
geologic mixing basin exists. Natural purification processes have limited
ability to remove contaminants because of the limited number of adsorptive
sites and exchangeable ions. Natural leachate treatment is also time depen-
dent; lower flowrates are more efficiently attenuated. A site's hydrology is
extremely important since it determines, to a large extent, leachate formation
and dispersion. Soil permeability is a measure of the rate at which water can
move through it. Coarse soils such as gravel and sand are generally more
permeable than fine grained soils such as silts and clay, but not necessarily.
For example, small amounts of fines in sand and cracks in clay can reverse the
respective permeability.
An artificial liner may be employed to control the leachate movement.
One of the most commonly used is a well-compacted clay soil, one to three feet
64
thick kept moist to prevent cracking. If sufficient clay soil is not avail-
able locally, natural clay additives may be mixed with it. The use of
additives requires testing to determine the optimum type and amounts. For
cohesion!ess soils, or situations where the necessary degree of compaction is
not practical, liners can be constructed of asphalt or polymer membranes.
Polymer membranes have not generally been used for solid waste disposal
sites, therefore, limited data are available regarding long term effectiveness.
The membrane covering should consist of a fine textured material which can be
placed with a dragline, conveyor, or truck. Heavy equipment cannot move over
the liners until they are protected with six to eight inches of cover. A
side slope of at least three to one is necessary to assure stability of the
cover materal on the slope. Before the liner is put in place, the slopes
should be graded and any debris that might damage the membrane should be
65
either removed or covered with a fine textured soil. The liner should cover
the sides of the basin to reduce the potential for lateral leachate movement.
Perforated pipes should be placed along the center lines of the disposal basin
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and covered wth granular materials such as coarse sand or gravel. The top of
the filled area is covered to reduce rainfall infiltration and the water which
does not enter the landfill is removed by the drainage pumps and a sump located
at one of the lower corners of the sanitary landfill. The water is pumped out
of the landfill for treatment or controlled discharge. If consideration is
only given to collecting the leachate and not controlled discharge, the
potential damage that the leachate represents may be considerable. A pond
of leachate with a high concentration of contaminants may buildup in the land-
fill. A rupturing of the liner would release a high volume of this leachate.
7.5.4 Surface Waters
The objectives of the Federal Water Pollution Control Act Amendments of
1972 are the restoration and maintenance of surface water quality. Accord-
ingly, all point source discharges of pollutants such as collected leachate,
surface runoff, and diverted groundwater must comply with state NPDES permit
requirements. The permit requirements are site specific in that they depend
upon the designated use of the surface water and the water flowrate. The
criteria also require the prevention of contaminated discharge into surface
waters of nonpoint sources when possible.
Leachate seepage and surface runoff should be collected through ditches
or trenches. The amount of water which enters the landfill site or moves
laterally as groundwater into the deposited refuse should be controlled. The
possibility of water entering a landfill site must always be taken into account.
Water contamination by infiltration is of concern when the solid waste is
placed where there is relatively unhindered flow from the solid waste to the
surface of groundwaters and when the distance from the landfill to the surface
water is unusually short. The waste should not be placed where there is
standing water, over coarse soils or fractioned bedrock, or near wells or
surface bodies of water. Special precautions should be taken to minimize
water pollution for such sites. Diversion of the surface water will reduce
mud and standing water on the site as well as reduce leachate production. A
conduit can be provided to channel streams through or under a landfill to
eliminate contact with the solid waste. Runoff from the landfill should be
diverted to one central point where it can be discharged to a water body or
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treated prior to discharge. One technique is to build a simple diversion
barrier at the top of the sanitary landfill to keep runoff from entering the
fill surface. The top cover material of the sanitary landfill should be
graded to reduce the residence time of the surface water, since the quantity
of water which infiltrates the landfill is a function not only of the per-
meability and the thickness of the cover but the length of time the water
stands on the surface.
One of the basic concepts of sanitary landfill design is that groundwater
and the deposited solids should not be allowed to interact. It should not be
assumed that the leachate will always be diluted in the groundwater since the
flow in the aquifer is usually laminar with little mixing. * When issuing
landfill permits, many states require that groundwater and deposited solids be
from two to thirty feet apart. Approximately five feet will remove enough
readily decomposed organics and coliform bacteria to make the leachate
bacterialogically safe. Mineral pollutants from iron and steel wastes,
however, can travel long distances through soil or rock formations. The
proposed rules for site selection for hazardous wastes require at least 1.5
meters (5 feet) above the historical high water table.
It is often possible to lower the groundwater in freely draining, gravelly,
and sandy soils. Drains, canals, and ditches are frequently used to intercept
an aquifer and channel it to the surface or a recharge area at a lower ele-
vation. Temporary methods of lowering the groundwater such as wells are not
advisable because the wastes can become saturated with water after the pumping
ceases. Also, highly permeable soils that can be readily drained will offer
little resistance to leachate movement.
A major preventative measure for reducing the possibility of the pollu-
tion of surface waters are to locate the site a safe distance from streams,
lakes, wells, and other water sources. The landfills should not be located
above the kinds of subsurface stratification that will lead the leachate to
water sources such as fractured limestone.
7.5.6 Flood Plains
If a facility is located in a lowland or relatively flat area adjoining
inland and coastal waters which are inundated by a flood which has a one per-
cent or greater chance of reoccurring in any year, then the facility must meet
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three criteria: (1) it must not increase the flooding upstream by preventing
the flow of water across the landfill site; (2) the landfill also must not
reduce the water storage capacity of site, which increases the flooding down-
stream; and (3) the flood water must not inundate the waste material.
The acreage of the flood plain consumed by the land disposal site should
be minimized. The nature of the waste should also be considered and the
permissible wastes in a flood plain should be limited to the more inert types.
A landfill located in a flood plain should be protected by dikes and
liners. The top of the dike should be wide enough for maintenance work to
be carried out and may be designed for use by collection and landfill vehicles.
The location of sanitary landfills in flood plains are discouraged since
the wetlands, surface water, and groundwater may be more sensitive to effluents
from the landfill. The EPA feels that although the environmental impact of an
53
individual site may be minimal the cumulative effect could be significant.
7.5.7 Safety
Surface ponding of certain coke plant wastes and other liquid wastes
are not acceptable if the gases produced from the liquid either by sublimation
or evaporation cause either a public nuisance or endangerment of the health.
The use of hazardous organic liquids for dust control is also undesirable for
these reasons. One major criteria for a sanitary landfill is the controlled
access to the disposal site. Complete prohibition of access to unauthorized
users is the most effective means of minimizing the risk of injury to other
persons. In most cases there is little economic impact on solid waste dis-
53
posal operation in accomplishing site access control. Potential harm to the
landfill personnel can be minimized with proper training and safety practices.
7.5.8 Other Criteria
Whenever possible environmentally sensitive areas should be avoided.
Other areas that are sensitive include active fault zones and karst terrain,
wetlands, and endangered species habitats. Sensitive areas may not be used
unless it is demonstrated that the facility will not jeopardize the biological
life in the area. Lined landfills should not be located over future mining
sites, abandoned mining sites, or unstable surfaces due to the potential
rupturing of the liner.
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8.0 IRON AND STEEL RECOVERY AND RECYCLING
There are four basic categories of solid waste from iron and steelmaking:
coke plant wastes, slags» iron oxides, and scrap. Essentially all scrap is
recycled to the steelmaking furnaces. Coke plant wastes are also recycled to
various operations with the exception of wash oil and tar sludges which are
.only partially recycled and lime sludge which is landfilled. Ironmaking slag
and, to a minor extent, steelmaking slag as well, are sold for by-product use.
The remaining steelmaking slag is either partially recycled to the blast
furnace or landfilled. A substantial portion of the iron oxide wastes,
especially steelmaking dusts and sludges are landfilled; the rest are recycled
to the sinter plant.
At present, various waste recovery processes are being implemented to
increase the utilization of iron oxide wastes. These include pelletizing of
the wastes to make them suitable for charging into the blast furnace, direct
reduction to remove and recover otherwise deleterious zinc and lead, and de-
oiling to facilitate the use of certain iron oxide sludges in the entire plant.
Various changes in the iron and steelmaking process, primarily implemented
because of economics, are also reducing the consumption of raw materials and
the generation of waste products. These changes include continuous casting for
better yield of semi-finished product, preheating of scrap and molten iron to
consume more scrap in steelmaking furnaces, and various modifications to
improve ironmaking in the blast furnace. The latter include external desul-
furization of iron, burden preparation, and fuel injection in the tuyeres.
Direct reduction of iron ore is also growing because it requires less invest-
ment than the blast furnace/coke oven alternative.
The full implementation of the above process changes in the industry would
increase the consumption of scrap (23 percent) and reduce the consumption of
coal (35 percent) and fluxes (24 percent). It would also reduce waste genera-
tion in terms of coke plant wastes (35 percent), iron oxides (14 percent),
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ironmaking slag (34 percent), and home scrap (22 percent). The reduced
generation of scrap, combined with its increased consumption would provide an
incentive for scrap recovery.
8.1 WASTE TREATMENT AND RECYCLE
This section discusses the current practices used to recycle wastes
including special treatment and handling procedures. Some of the most common
methods of resource recovery and recycle are described, as well as identifica-
tion of promising new uses for waste materials. One example of how the iron
and steel industry can increase the resource recovery from other segments of
the economy is discussed briefly.
8.1.1 Coke Plant Wastes
Coke plant wastes, particularly tars and oils, should be recycled or
burned in an oxidizing atmosphere whenever possible. Although the composition
and quantity of these wastes is determined by the recovery and operating
practices used, the ones of interest are: coke breeze and residues, by-
product coke gases and tar sludge, ammonia still lime sludge, and wash oil
sludge.
A wide variety of processes exist to capture and treat by-product coke
gases and various combinations of these processes are practiced throughout the
industry. Due to the carcinogenic and toxic nature of coke oven by-products,
special environmental considerations should be given to them.
Coke breeze is small particles (36 kg per tonne of coke) screened from
the coke before it is charged to the blast furnace. These particles are too
small to be charged into the top of the blast furnace because the furnace
draft would only blow them out the top. Also, the breeze could interfere with
the permeability of the burden. The breeze and residue from pollution control
devices are recycled through the sinter plant as fuel, recharged into the coke
oven, used as soaking pit lining, or, infrequently, briquetting. It is sold
as product only when there is an excess.
Tar sludge collects in the tar decanter and various storage tanks. Par-
ticulates entrained in the tar and coal and coke fines collected during coal
charging accumulate in the sludge also. The composition of the sludge is
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expected to be suitable for recycle into the coke ovens or agglomeration
processing in a reducing atmosphere.
Ammonia still lime sludge is formed when tar and oils in the ammonia
water encapsulate the particles in the lime slurry. In general, this sludge
is disposed of by landfill ing.
Wash oil sludge accumulates in the oil used to scrub light oils from the
coke oven gas. Currently the sludge is either burned in an open hearth
furnace or recycled through the coke ovens.
8.1.2 Iron and Steelmaking Slags
One-third of the industry-generated solid waste is slag. Slags are
required in metallurgical processing to remove unwanted elements such as
sulfur and phosphorus and also to protect the metal from reacting with the hot
18
gases. Apart from the metallurgical use, slags have a wide variety of non-
metallurgical uses also. There are three major types of blast furnace slags:
air-cooled, granulated, and expanded.
Air-Cooled Slag
Molten blast furnace slag is permitted either to run into a pit or trans-
ported in ladles and poured on the ground some distance away from the furnace.
With either method, the slag is cooled and quenched with water to hasten the
process. After cooling the slag is dug, crushed, and screened to the desired
aggregate and used for a variety of purposes. A magnetic pulley is often used
to recover iron for charging into the blast furnace.
Some of the major useful properties of this slag are weathering and
abrasion resistance and its noncorrosive nature. Table 67 presents a summary
of the uses of air-cooled slag. It is immediately obvious that nearly all the
slag consumed in the United States is in the construction industry. The major
uses include highway and airport construction as well as railroad ballast.
Whenever slag is economically available, it is used extensively as a
coarse aggregate in many types of concrete. Because of the voids in the
slag, it is a preferred material for high strength and light weight. The slag
aggregate pavements are reported to exhibit unusually high skid resistance.
Slag has a unique combination of resistance to polishing and abrasive texture.
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TABLE 67. USES OF AIR-COOLED BLAST FURNACE (1976)
Use
Cement aggregate
Bituminous construction
Highway and airport
construction aggregate
Concrete block aggregate
Railroad ballast
Mineral wool
Roofing cover material
Roofing granules
Sewage trickling filter
Agricultural
Other uses
TOTAL
Quantity
(thousand
tonnes)
1753
3691
9713
270
689
189
12
10.9
55
988
20,820
Percentage
8.4
17.7
46.6
1.3
16.5
3.3
0.9
0.06
0.05
0.26
4.74
Value
($/tonne)
3.27
3.08
2.90
3.39
2.23
3.24
3.9
4.48
6.05
3.66
2.64
2.87
Other uses of slag include the production of a high quality mineral wool from
it. The mineral wool is durable, lightweight, and has a high insulation
value. Slag is extensively used as the granular material on composition
shingles and roofing.
Slags have been used to condition soil with respect to basicity and humus
content. The lime in the slag is in a useful form since it is slowly leached
out and does not burn like ordinary lime. Although slags which are used for
agricultural purposes are not fertilizer, they do contain some fertilizing
18
elements. Slags have been used as soil conditioners for almost a century.
Whenever slags are used to condition soil, special consideration should
be given to the long range effect of heavy metals such as cadmium. Special
criteria have been proposed by EPA for the use of waste for the production of
53
food chain crops. At the present time, the criteria only address cadmium
but other metals will be addressed in the future, as well as organics. The
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current criteria establish the amount of cadmium which can be added per acre,
as well as restrict the use of solid waste which contains greater than 25 ppm
Of cadmium for the production of food chain crops. Additional slag composi-
tion information may be required to establish the environmental impact for its
use in agriculture.
Granulated Slag
Granulated slag is formed when the molten blast furnace slag is rapidly
chilled, thus preventing the formation of crystal structures. Depending upon
the composition of the slag and the chilling process, the structure can vary
from a friable, popcorn-like structure to grains resembling dense glass.
Granulated slag has excellent hydraulic properties so that it will set up
similar to cement when compacted in the presence of water. When properly
compacted, it can be used as a base for pavements, runways, and parking areas
because it increases the support with age. Table 68 demonstrates the relative
amounts of granulated slag used in a variety of applications.
TABLE 68. USES OF GRANULATED BLAST FURNACE SLAG (1976)
Use
Road construction and fill
Agriculture
Cement
Concrete block aggregate
Other uses
TOTAL
Quantity
(thousand
tonnes)
1090
53
79
113
134
1471
Percentage
74.1
3.6
5.4
7.7
9.1
Value
($/tonne)
2.14
3.13
4.22
3.99
1.79
2.34
Granulated slag is used in the manufacture of portland blast furnace slag
cement. The slag constituent is between 25 and 65 percent by weight. The slag
cement can be used in combination with portland cement in making concrete and
with lime in making masonry mortar.
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Expanded Slag
Expanded slag is obtained by the controlled expansion of molten blast
furnace slag with water or air. A variety of techniques are employed for
expanding the slag, the physical properties of it depending upon the technique
used for the expansion. The cellular structure is more pronounced than with
air-cooled slag. Expanded slag is commonly used as an aggregate for concrete
block manufacturing. Other uses include lightweight, structural concrete and
use as a lightweight fill. Slag has good compatibility in concrete mixes and
possesses a number of desirable properties. For architectural purposes, the
high sound transmission loss and the light surface texture are desirable.^
The higher insulating values of this type of slag masonry units provide better
protection against condensation on walls and reduce energy requirements for
heating and cooling. Expanded slag is also very useful for creating embank-
ments since it is easily compacted and has good drainage and an inherent
cementing action. Some of the uses of this slag are presented in Table 69.
TABLE 69. USES OF EXPANDED BLAST FURNACE SLAG (1976)
Use
Concrete block
aggregate
Lightweight concrete
Other uses
TOTAL
Quantity
(thousand
tonnes)
1271
8
77
1356
Percentage
93.7
0.6
5.7
Value
($/ tonne)
5.02
5.74
2.34
4.87
Steel Slag
Steel slags are fundamentally different from blast furnace slag and con-
sist of calcium silicates, calcium oxide-ferrous oxide solid solutions, oxides,
and free lime. There is variation in composition due to the batch nature of
the process. The calcium and magnesium oxides can be hydrated with expansions
of up to 10 percent. This uncontrolled expansion severely limits the use of
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steel slags in Portland cement concretes, since expansion can destroy the
concrete. Structural failures can result from the indiscriminate use of steel
slag in confined applications. The hydration of unslaked lime occurs
rapidly (several weeks) but magnesium oxide hydrates more slowly (several
years).
Aging for a period of at least six months can be useful in controlling
CO
the expansion. Several treatments can be used to accelerate the expansion
of the slag, thus reducing the expansion in use. When the metallies are
recovered by crushing, and water is used in processing, the aging process is
accelerated. Spent pickle liquor (H^SO,) has been used to .accelerate the
aging of slags, and the effectiveness of the treatment is related to the
contact time with the acid. This process is also expected to free some of the
heavy metals bound in the steel slag.
These slags are used mainly for unconfined base fill and highway shoulders
(Table 70). Steel slag is used as railroad ballast, although in substantially
less quantities than air-cooled blast furnace slag.
One use of steel slag which has not been fully developed is the formation
of very stable mixtures with asphalt. Some useful properties of this blend
are good flow, very high stabilities (two to three times greater than current
aggregates), adequate compactability, excellent stripping resistance, and good
wear and skid resistance.
An increasing amount of steel slag is being recycled to the blast furnace
on
since 1972. This is done to recover their iron and manganese contents,
since these metals are reduced and become part of the iron. The lime content
18
of the steel slag acts as a flux. There are conditions under which the
steel slag cannot be returned to the burden of the blast furnace. These
include additions during specialty steelmaking, no recycling equipment avail-
able, non-integrated operations, and unfavorable economics. With increasing
raw material costs and high disposal costs, it is likely that a higher per-
centage of steel slags will be recycled in the future.
Basic open hearth slag has been used, especially in the southern states,
as a soil conditioner. The high phosphorous content of the open hearth slag
resulted from the high phosphorous content of local ores. Other open hearth
furnace slags are used in areas for conditioning already phosphorous-rich soils
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TABLE 70. STEEL SLAG USES (1976)
Use
Railroad ballast
Highway base or shoulders
Paved area base
Miscellaneous base
Bituminous mixes
Other uses
TOTAL
Quantity
thousand
tonnes )
423
2160
1557
1284
321
244
5989
Percentage
7.0
36.1
26.0
21.4
5.3
4.1
Value
($/tonne)
1.51
1.63
1.66
1.62
1.59
1.54
1.62
because of the amounts of elements such as iron, boron, zinc, molybdenum, and
18
copper which are needed in states such as Florida.
8.1.3 Iron Oxide Recycling
Iron oxide wastes in the form of dust, scale, and sludge comprise over
20 percent of the steel industry's process wastes that are landfilled, and are
probably the most valuable with respect to potential resource value. Sinter
and blast furnace dusts are presently recycled to the sinter plant to recover
iron and carbon values. About 70 percent of the mill scale can be readily
recycled with the heavy, coarse pieces delivered directly to the blast furnace
and smaller pieces incorporated into the sinter mix. A few plants may be
unable to use scrap containing zinc and lead in steelmaking so that the dust
can be recycled, or they may segregate the dusts for those periods of time when
such scrap is used.
The balance of the mill scale, sludges, and steelmaking dusts are not
routinely recycled due to the presence of oil, water, tramp elements (zinc,
lead, and alkalis), and/or small particle sizes (fines). These wastes will be
examined with respect to dealing with the problems of recycle, namely agglomera-
tion to solve the fines or water content problems, tramp element removal, and
de-oiling to eliminate the hydrocarbon emissions problem.
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Agglomeration Processes
Many agglomeration processes are available and have proven successful in
producing hard briquettes or pellets than can be handled, transferred, stored,,
and charged to the blast furnace or steelmaking furnace. The application of
these processes would be limited to those specific locations where the tramp
element content does not present a serious problem since no provision is made
for zinc and lead removal.
The Reclaform process was developed by the Reclasource Corporation of
Chicago, Illinois and has been successfully used in a demonstration plant. A
hot mix of iron and carbon wastes is briquetted with a binder and cured by
baking to form a strong coke bond. For example, coke breeze, furnace dust,
oily mill scales, filter cakes, and sludges can be agglomerated with a car-
bonaceous binder (e.g., coal tar pitch) to yield a strong, durable briquette.
A 20-day trial was conducted at Crucible Steel (Midland, PA) in which the
briquettes were successfully utilized as 10.5 percent of the blast furnace
burden. Both iron and carbon values were recovered in the Reclaform test.
The company is developing detailed engineering plans for a 318,000 tonne per
year (350,000 tons per year) plant that is still in the planning stage. No
commitments have been made for construction, but tentative plans are targeted
for 1981 at a cost of approximately $10 million. A company spokesman stated
that a 100,000 ton per year facility would be the minimum size that could be
economically feasible, with an estimated capital requirement of $5 million.
The Pelletech Corporation of Pittsburgh, PA has demonstrated an alter-
native for handling waste fines with a process called the MTU cold-bond pro-
cess. This procedure takes ground mill scale, blast furnace dust, and steel-
making dust and combines 4-5 percent burnt lime and 1-2 percent silica flour.
These solids are then mixed with water, aged for several hours to assure
complete hydration of the lime, pelletized in the form of balls, and then
dried. This process was successfully tested during a two week run at Kaiser's
Fontana (CA) plant where the balls were used as 10 percent of the burden in
the blast furnace. A Pelletech representative stated the minimum economical
plant size is 150,000 TPY, but he added that research is continuing with hopes
of developing an economical 25,000 TPY process. The company is currently
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offering to build, operate, and finance a pelletizing plant with a long term
contract to cover certain fixed charges for any interested steel plant. The
pellets will be made from iron oxide wastes and will be sold to the steel
72
plant at a cost less than the value of the contained iron.
Republic Steel has been operating a 10 ton per hour briquetting facility
using the Aglomet process at its Chicago plant. Waste materials include blast
furnace dust and sludge, EAF dust, Q-BOP filter cake, mill scale, scarfing
dust, and slag fines. These wastes are hot-briquetted in a fluidized bed at
870-980°C, and are being stockpiled for a blast furnace test at a later date.
The COBO process licensed by Sala International is similar to the MTU
process and has been demonstrated in Sweden for pelletizing chromium ore
fines. This process also uses grinding, blending with lime and silica,
balling, and then hardening to form cement-type calcium silicate bonds.
Although it has not been demonstrated in the steel industry, the COBO process
should be feasible in agglomeration of iron oxide wastes.
Granges Engineering of Sweden has developed a pelletizing procedure
called the Grangcold process. Coke breeze, mill scale, and steelmaking dust
are wet ground in a ball mill, mixed with Portland cement, and then balled.
The pellets are hardened in bins for six days, then cured two to three weeks
out-of-doors to complete the hardening process. No commercial facility has
yet been built to use this process in the handling of plant dusts.
The Blocked Iron Corporation has developed a carbonate bond pelletizing
process in which the wastes are mixed with coal and 10 percent lime hydrate.
The mixture is balled, dried, and carbonated in a carbon dioxide rich atmos-
phere. A blast furnace trial has been conducted in which the pellets performed
satisfactorily and no operating difficulties were encountered.
The Obenchain system is another cold-bonding process that uses a modified
lime-silica combination as the binder. In April 1971, a pilot plant was
installed in Trenton, Michigan. During its operation, this plant produced
12,000 tonnes of pellets that were used in McLouth Steel's blast furnaces
for up to 20 percent of the burden. This operation was stopped due to a
74
change in McLouth's operation that reduced the amount of iron ore fines.
149
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A technique for recycling some steelmaking dusts back into the steelmaking
furnaces has been practiced by U.S. Steel. When used in these furnaces, the
agglomerated product does not have to be as strong as required in the blast
furnace and some tramp elements can be tolerated. The dry dust is mixed with
water in a balling disc to produce pellets that can be transferred and exposed
to high temperatures without disintegration. This has been practiced for
three years at U.S. Steel's National-Duquesne plant where almost all of the
EAF dust has been balled and recycled back to the EAF. No operating problems
have been observed and a benefit of reduced fluorspar usage has been noted.
Recycling pellets to the steelmaking furnace has two effects. One is to
supply a portion of the iron oxide which is dissolved in the slag, increasing
the metallic yield. A negative aspect is that more energy is required to
reduce the iron oxide than it does to melt the scrap, or refine the molten
iron, that it replaces.
Pellets were produced from open hearth dust at U.S. Steel's Homestead
Works as a partial substitute for the ore charge in the open hearth furnace.
A two-day test revealed no operating problems or changes in yields or heat
times. The sulfur content of the melt increased 0.003 percent. An extensive
s
test of this procedure was conducted at U.S. Steel's Youngstown Plant over a
three-month period without operating problems. The sulfur content of the melt
increased 0.004 percent and required additional lime, but the data suggested
that the open hearth dust could be recycled for an extended period of time in
the open hearth furnace.
Bethlehem is using similar procedures at its Sparrows Point, MD and
Bethlehem, PA Plants based on their U.S. Patent No. 4,003,736 and No. 4,
004,916. At Sparrows Point, sludge is collected from wet scrubbers on the
open hearth and BOF furnaces and goes to a thickener. The slurry is then
spray dried, fed to an impactor, and agglomerated in a pelletizing disc. The
agglomerate is recycled back to the BOF or open hearth furnaces. At the
Bethlehem plant, the steelmaking fume is collected as a dust, mixed with water
in a pelletizing disc, and converted into balls. These balls are then recycled
through the sintering plant. The Bethlehem unit turns out 110 tonnes per day
and the Sparrows Point unit produces 273 tonnes per day. The cost of installing
150
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these pelletizing units can be recovered in savings by reducing the outside
purchase of iron ore and pellets.
Direct Reduction Processes
Because of their fine size and the presence of zinc, lead, and alkalis,
steelmaking dusts and sludges have been considered unsuitable for recycle
through the sinter plant and blast furnace. Zinc is particularly troublesome
since it can affect blast furnace productivity by (1) reducing furnace per-
meability and forming scaffolds, (2) degrading refractory lining, and (3)
forming blockages in the gas cleaning.system. The direct reduction processes
convert steelmaking dusts with a high zinc content to pellets with a high
level of metallized iron and low zinc, lead, and alkali content. The tramp
elements are volatilized and concentrated in the offgas dust which may be sold
to zinc smelters if the zinc content is high enough. Several of these pro-
cesses have been tried and proven technically feasible, but the economic
feasibility is still debated in the U.S.
Full scale application has found wide acceptance in Japan and seven
commercial direct reduction plants are in operation and use processes that are
very similar. A generalized flowsheet is shown in Figure 24 that is applicable
to the Kawasaki, SL/RN (Stelco-Lurgi/Republic National) and Sumitomo dust
reduction processes. The waste solids are mixed together, pelletized, pre-
heated on a grate, and then reduced at 1100-1150°C in a rotary kiln. Carbon
in the dust, added coke breeze or coal serve as reductants. Approximately 95
percent of the lead and zinc are removed as well as 50 percent of the NagO and
KpO (alkalies). The metallized pellets are cooled and sent to the blast
furnace, and the zinc oxide dust collected from the offgas can be used by zinc
processors.
The Kawasaki Steel Corporation recently (1977) installed its third direct
reduction plant at a cost of $24 million. With a 600 tonne per day capacity,
this required an investment of $110 per annual tonne of output pellets.
A representative of Kawasaki Steel said that their direct reduction
plants were still in operation and were economical. He also stated that a
78
U.S. engineering firm is negotiating to license their technology.
151
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WASTE-DUST GRATE-KILN DIRECT-REDUCTION PROCESS FLOWSHEET
01
r\»
DRY WET
DUSTS DUSTS
CO,
COKE
YCLE
nr
LfiilH&J
1 DRYER I
lmmm»mium,,tmmmil
t t
|2_M1XER_I
M OR J
:"™<-"™|— -™11 ZINC COLLECTION |
PREHEATER I |
— ,f . ,i j
— " — '""" 1 1 OHF- GAi
t
COOLER I-"*1 "WATER
t^^
SEPAR^
^TION l-«-«np««-nI
PRODUCT
Figure 24. Waste-dust grate-kiln direct reduction process flowsheet.70
-------
Sumitomo has two plants operating, one that produces reduced pellets for
the blast furnace and one producing dezinced material for the sinter plant.
The latter type of plant requires lower capital investment since an existing
sinter plant is used for agglomeration in lieu of building a pelletizing
plant. However, oxidation of the metallic iron makes the sintering route
undesirable. A Sumitomo representative felt that the use of the zinc dust for
79
zinc recovery and strict landfill ing regulations made the process economical.
Nippon Kokan K. K. (NKK) has utilized the SL/RN process in a 360,000 TRY
plant since 1974. Their representative said the plant was still operating and
was economical in 1974, but that the rising cost of energy in recent years may
make the economics marginal.
The seven Japanese direct reduction recycling plants have an average
capacity of 233,000 tonnes per year, and are located at large steelmaking
complexes. A regional treatment facility may be required in the U.S. if
American steel companies are to take advantage of the economy of scale (Sec-
tion 6.2.5). Few individual plants in the U.S. generate 100,000 to 400,000
TPY of dust with a high zinc content and recovery of the zinc may be a
controlling factor in an optimistic economic evaluation.
A U.S. source estimates an investment cost of $138 per annual tonne of
reduced pellets for a direct reduction plant, and states the energy require-
81
ments can range up to 4 million kilocal ories per tonne of pellets. Some of
this energy will be recovered in blast furnace fuel savings due to the
metallized iron content of the pellets. Savings on land disposal costs and
credit for the zinc dust would also help to recoup operating expenses. How-
ever, although several of these processes have been tried and proven tech-
nically feasible, the economic feasibility is still being debated in this
country.
The Waelz process is a direct reduction technique that has been used for
20 years to refine low grade zinc ores. The Berzelium and Lurgi companies
have conducted a large scale experiment in Duisburg, Germany, that used iron
and steelmaking dusts. Mixtures of waste dust containing 40 percent blast
furnace sludge and 60 percent BOF dust that was analyzed at 44-50 percent
iron, 2.5-4.5 percent zinc, 1-2 percent lead, and 3-8 percent carbon were
153
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reduced in the Waelz kiln. The feed was prepared by simple mixing, and after
reduction, the fines were briquetted with sulfite waste liquor as the binder.
These briquettes were used at a rate of 160 kg/tonne iron in the blast furnace
for 16 days and no variations in the metallurgy were noted.
The experimenters observed that dezincification was possible with a con-
tinuous process, 95 percent of the zinc and 50 percent of the alkalis were
removed, and 95 percent of the iron was metallized. The advantages of this
process are that it can operate economically on a lower throughput (100,000
TRY) than other direct reduction processes and it is less sophisticated in
that there is no pelletizing before reduction. The sponge iron product may be
charged to the steelmaking furnace, or it could be briquetted after reduction.
A valuable zinc by-product (Waelz oxide) is recovered from the offgas, and
oily mill scale can be used in the kiln feed with no adverse effects.
Lurgi provided a cost estimate for the production of reduced pellets at a
Op
May 1978 symposium (Table 71). The processing cost of $240 per tonne does
not appear economical when considering that the Midrex Corporation sells
83
reduced iron pellets to steel companies at $120 per tonne. However, other
factors that may improve the economics and must be considered for specific
cases include (1) the availability of reductant (carbon) from coke plant
wastes at a much lower cost, (2) the value of the zinc oxide by-product, and
(3) savings on landfill charges.
Inland Steel participated in a pilot plant test of the classical Waelz
process in cooperation with Heckett Engineering and the Colorado School of
Mines Research Foundation. The conclusion was that the process was not
satisfactory for commercial application due to the low compressive strength of
the pellets, loss of iron oxide into the zinc precipitate, and high rate of
recirculation of fines. Another program was initiated with Heckett Engineering,
Stirling Sintering, and the Krupp Company to investigate the Krupp process, a
modified version of the Waelz process. The program was technically successful
but commercial application was dependent on the regional plant concept. The
economics dictated a minimum 364,000 tonnes per year facility to service the
84
Chicago area steel mills.
154
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TABLE 71. COST ESTIMATE FOR WAELZ PROCESS (400.000 TPY PLANT)
82
Expense
Quantity
(per tonne of feed)
Cost*
($ per tonne of feed)
Reductant
Heating agent
Electric energy
Water
Binder
Utilities
Brickwork
Repair, maintenance
Personnel
Amortization and interest
270 kg carbon
—
40 kwh
lm3
18 kg
—
1.2 kg
—
0.35 hr
102.40
18.45
5.17
1.85
9.96
0.92
2.58
16.42
12.92
69.19
Processing cost + amortiza-
tion + interest
239.86
*Assumptions:
1. 15 percent annual interest.
2. Capital costs include 15 percent for infrastructure.
3. Includes a briquetting charge of $27.68/tonne.
4. Exchange rate of 0.542 marks = $1.00 (1/16/79).
Obenchain has also developed a direct reduction process that was demon-
strated at an American steel plant. ESP dust, open hearth dust, and coke
fines were used to produce pellets that were charged to a cupola, melted, and
yielded molten iron. No commercial application is in use in the U.S., but the
company is planning a 40,000 tonne per year plant in Central America for iron
ore reduction at a cost of $2.1 million.
De-oil ing
Scale and sludge generated in the rolling operations are contaminated
with oil and grease that make recycling difficult. Because these materials
contain oil, they may cause excessive stack opacities if recycled to the
sinter plant. To avoid these problems, the plant often decides to dispose of
155
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the waste rather than recover it. The various options for dealing with the
situation are:
1. Dispose of oily scale and sludge to landfill or stock
for future use. This causes the loss of a valuable
natural resource and presents the possibility of ground
water contamination.
2. Recycle through the sinter plant by upgrading the air
pollution controls for the windbox to cope with the opacity
problem. If the control is by baghouse, this is not tech-
nically feasible because the oil vapors present would lead
to bag blinding. If the control is by ESP, the control
equipment is unable to control the oily vapors. If the
control is by scrubber, the capture of oily vapors would
require an inordinate consumption of fan power and of
capital to install new control equipment.
For example, consider an average sized sinter plant which
produces 6350 MT/day of sinter. Gas flow would be about
490,000 MM3/hr. The existing fan may require 2500 KW to
provide 1150 mm of suction for process suction, including
scrubber differential pressure. In order to effect control
of oily vapors, another 750 mm of differential would be
needed, thereby consuming 1500 KW more. The plant generally
decides that economics favor the elimination of oily
materials from the sinter mix over upgrading the windbox
controls.
3. De-oil the scale and sludge. There has been considerable
effort along these lines but generally without success
to date. A possible exception is a process developed by
Colerapa Industries, Inc. (Ravenna, OH) that has been
used by the Steel Company of Canada. This process takes
mill scale and sludge that have been dredged from lagoons
and sends it through an oil scrubber, screening operation,
and thickener. The de-oiled iron oxide is recycled to
the sinter plant at a rate of 36,000 tonnes per year. The
application of this process appears to be based on pollution
control requirements. The detailed economics of this
process is unavailable.
The development of successful methods for de-oiling would be an advantage
to resource recovery and to the elimination of solid waste.
8.1.4 Waste Pickle Liquor
Steel finishing requires pickling, or acid dipping, to remove the black
oxide scale that forms during the process. This is required not only for
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aesthetic reasons but is a mandatory step prior to cold rolling. The disposal
of the tremendous quantity of acid consumed in this process is a major
environmental problem and recovery of the chemical value in waste pickle
liquor has been an objective in past decades. However, until 1976 there were
88
no economical recovery processes available for HC1 pickle liquor.
The economic changes during the 1970's have generated an increasing
interest in reassessing the possibilities of pickle liquor recovery. From
1972 to 1977 the cost of acid and its disposal have increased 150 percent.
Regeneration costs during this period increased only 50 percent, and since
1976, the trend continues to indicate that resource recovery is the more
economical method.
The pickling of steel was formerly done with sulfuric acid, which is
still relatively inexpensive. In recent years, however, the industry has
discovered that hydrochloric acid gives better results in half the time,
thereby enabling an increase in production rates without additional capital
expense. Much of the industry is now depending on hydrochloric acid to achieve
their normal production rates. The elimination of fluorocarbon aerosols, the
manufacture of which produced hydrochloric acid as a by-product, and changes
in the oil industry's operating methods, have reduced this supply, and
resulted in prices three times that of sulfuric and supplies of questionable
dependability. These factors together with environmental requirements to
abstain from spent acid dumping are creating a new interest in acid recycling.
Acid Regeneration
The Ohio River Valley Sanitation Commission initiated a pilot plant
program in 1952 to make use of the Blow-Know and Ruthner double cycle acid
86
regeneration process. It was reported in 1958 at the general meeting of
135
AISI to be a technical success. It is the only known process that actually
regenerates sulfuric acid from the iron sulfate produced by pickling.
The iron sulfate is converted to iron chloride in a regeneration plant by
reaction with hydrochloric acid, producing sulfuric acid as a by-product which
is recycled to the pickling plant. The iron chloride is roasted to recover
the iron oxide for recycle. The complexity of the process was considered
unsuitable for steel plants.
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Acid Recovery
The only successful and continuing process for recovering sulfuric pickle
liquor is an acid recovery process. This process essentially purifies the
waste pickle liquor (WPL) by removing the FeSO^ so that the unconsumed acid
remaining is available for use. This reduces acid consumption by 50 percent
in most plants.
Unlike the case with hydrochloric acid, the buildup of iron sulfate in
t^SO^ solution significantly decreases the activity and reaction speed, and
results in the pickle liquor being discarded when it is still 8 percent HgSCL.
In the recrystallization process, WPL is cooled to a low temperature,
sometimes after evaporative concentration. Crystals of iron II sulfate hepta
hydrate form as fast as the solution is cooled. These are removed by decan-
87
tation or centrifugation. The remaining purified liquor is strengthened by
the addition of acid and returned to the pickle tanks. The ferrous sulfate
formed can be sold for use in inks, dyes, paints, fertilizers, and as a floc-
culating agent in waste treatment and sewage plants, an expanding market. In
1976 there were only 20 recrystallization plants in North America, three were
19
continuous process systems (2 in Canada) and 17 were batch processes.
Sulfuric acid has always been consumed in proportion to a Nation's produc-
tivity and is still relatively inexpensive at $27/tonne. Thus, the major
incentive for sulfuric acid recovery is as a solution to the waste disposal
problem.
Hydrochloric Acid Regeneration
The pickling of steel with hydrochloric acid produces ferrous chloride,
which is dissolved in the pickling acid. The activity of acid chloride solu-
tions is very high resulting in a usable pickling speed until all but one
percent of the acid is consumed. The only practical operation that can be
performed on the hydrochloric WPL is to regenerate HC1 from FeCl2. There are
several processes that differ in approaches but all involve reacting iron
chloride with water in the presence of heat to produce iron oxide and hydro-
chloric acid.
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Spray Roaster Type Process
In the Pennsylvania Engineer!ng/Woodall Duckham spray roaster process,
the spent liquor is sprayed into the top of a cyclone-like chamber. Fuel and
air are blown into the bottom of the chamber tangentially. The liquor under-
goes the chemical reaction at around 1000°C and produces a powder of Fe90o
£ J
that falls to the bottom. HC1 gas and water vapor are also produced and are
passed on to a scrubber and absorber to recover an aqueous solution of HC1.
The Ruthner Industrieanlagen of Austria also makes these plants. The major
advantage of this system is that the fine powder form of Fe203 commands a high
price from the ceramic magnet industry ($176/tonne, 1978). The disadvantage
of the process is that operational constraints require a roasting chamber at
least 1.83 meters in diameter, making 4 liters per minute the minimum size
reactor that operates satisfactorily. In all the thermal regeneration methods
for HC1, 752 kilocalories per liter of waste pickle liquor is required. This
amounts to 1/10 liter of oil per liter of pickle liquor.
Fluidized Bed Roaster
In 1936, Lurgi developed a roasting process in which the reactor is a
fluidized bed of iron oxide. The waste liquor is sprayed into this and the
Fe304 is recovered in the form of pellets. This is convenient for handling
but does not command as high a price as the powdered Fe^O.,. This process is
efficient, recovering 99.5 percent of the acid, with almost complete absence
of iron in the regenerated acid. Such purity, however, does not improve the
pickling process.
Sliding Bed Regeneration
The sliding bed reactor was designed to be suitable for small installations
of 20 to 60 liters per minute. Preheated waste pickle liquor (HC1) is sprayed
on a bed of hot iron oxide that slides down an inclined furnace. Thermal de-
composition converts iron chlorides into hydrochloric acid and iron oxide in
the combustion zone of the furnace. The acid is vaporized and absorbed in
water. At the bottom of the incline a system of buckets collects the oxide
and carries it back to the top of the bed. Excess iron oxide is removed as
required.
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Operational Aspects of Regeneration
Although articles have been written claiming that regeneration of HC1 is
economical, since 1976 the reputation that regeneration is not profitable in
itself is still in wide circulation. Discussions with an industry source
using spray roasting revealed that, of itself, regeneration is not profitable.
The plants also have a high maintenance factor due to the abrasive nature of
FegOg and corrosion problems which are being solved incrementally. One manu-
facturer of pickle lines commented that when their customers learned that
regenerating acid cost more than buying acid, they refused consideration of
the topic.
The economics of acid regeneration are strongly influenced by the market
available for the by-product iron oxide. The market for iron oxide in the
production of magnets is estimated as 700 tonnes per year, much less than the
industry could produce if all the pickle liquor was regenerated.
An industry source that does use regeneration revealed that continuation
of the process was based on a wider view than just the cost of acid versus
regeneration. The reasons given in favor of the process were:
1. Regeneration gives the company a guaranteed acid supply.
2. Regeneration eliminates disposal problems. It is cheaper
than having the spent liquor hauled away in their location.
3. As an item of pollution control equipment, regeneration has
a better payback than any other pollution control system.
This last comment indicates the importance of having acid regeneration systems
classed as pollution control equipment for tax purposes.
Discussion with one U.S. steel producer presently enjoying cheap disposal
in a deep well indicated that they are aggressively evaluating possible
methods of regeneration because:
1. The cost and supply of HC1 is uncertain for the future.
2. Their deep well could freeze up and be inoperable.
3. It appears that drilling another well may not be allowed.
Ten percent of hydrochloric acid used for pickling in the U.S. is regen-
erated, and 10 percent of sulfuric acid is recovered. Estimated comparison
160
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data with other countries are as follows: Japan-75 percent, France-40
percent, Germany-45 percent, Austria-50 percent, USSR-20 percent, United
Kingdom-60 percent, Canada-75 percent, and Brazil-45 percent.
In summary, recycling waste acid has had a difficult development period
in the U.S. probably because of a previous abundance of low cost materials and
environmental standards. The future of recycling waste pickle liquor in this
country looks promising due to changing conditions in the industry.
8.1.5 Scrap Recovery
Approximately 30 percent of the waste generation of iron and steel
production is scrap metal. This metal is completely recycled and used to
produce steel. EAFs can use a large amount of scrap metal as feed since
energy is required to convert iron oxide to iron and the scrap is already in
metallic form.
Obsolete scrap is also used in the steel industry. This scrap comprises
worn out or broken products of the consuming industry and includes stoves,
useless farm equipment, wrecked automobiles, etc. This scrap requires care-
ful sorting to prevent contamination of the steel in the furnace with
unwanted chemical elements that may be present in the scrap.
Due to the intrinsic energy value of scrap iron, as well as the material
resource, the use of ferrous scrap from municipal refuse will be briefly
considered. Scrap shortages are predicted by some experts in the iron and
on
steel industry. The amount of ferrous municipal scrap is estimated as 10
million tons annually, 10 percent currently used in ferroalloy and copper
production.
When incinerated, municipal refuse contains 30 percent ferrous scrap in
the residue. Incineration increases the copper content of the scrap, since
the copper plates out on the metal. Incineration can also oxidize some of the
iron as well as alloy the tin so that it cannot be removed.
Nonincinerated scrap can be altered to recover the iron for use in steel
production. Magnetic separation is used to reject nonferroiis material, and
the composition of tramp elements is generally lower than for magnetically
separated incinerated scrap. The aluminum content is somewhat higher in
nonincinerated scrap, however. The tin can be removed from the nonincinerated
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scrap, or if the tin content is low enough, simple dilution with virgin
material can lower the tin content in the hot metal to within acceptable
bounds.
Useful scrap metal for the iron and steel industry can be obtained if the
recovery system is properly planned and operated. This is a major area where
governmental assistance can prove useful in resource recovery. Adjustment of
transportation costs could also provide an incentive for scrap recovery.
8.2 EFFECT OF PROCESS CHANGES ON WASTE PRODUCTION
For the most part, steelmaking technology today is essentially the same
as it was in the past century. There is still major reliance on the coke
oven-blast furnace route of ironmaking as the first step in the steelmaking
process. These processes have become larger and their control has become more
sophisticated; however, their basic function has not altered.
Process changes that have come into wide utilization are sintering for
agglomeration of fine ores and process wastes, the use of pelletized ore, the
BOF to replace the open hearth, and continuous casting to replace conventional
ingots. Even the BOF is but an update of .the pneumatic process originally
invented by Bessemer.
The steel industry is starting to direct its efforts toward some more
basic changes in steelmaking. In general, these new methods will provide more
continuous processing and greater containment of the processes than before.
It is unlikely that these basic changes will come into any substantial utili-
zation before the next century, due principally to the problems of raising the
necessary capital, the conservatism of the steel industry towards the applica-
tion of new technology, and in some cases, the additional energy cost.
In general, any innovation or improvement in steelmaking that increases
its efficiency and reduces its costs also tends to reduce environmental pro-
blems, including generation of solid waste. At worst, the effect of the
change on the environment is neutral. The net effect almost never results in
deterioration of the environment.
Changes in iron and steelmaking practices fall into three categories in
respect to their state of implementation in the industry. These categories
are more fully described in the next paragraphs.
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8.2.1 Changes Not Reduced to Practice
There are a number of radical changes in steelmaking technology which
may have a substantial impact on the generation of solid waste. They have not
been reduced to practice within the industry and their future is somewhat
uncertain at this time. For this reason, only a brief description is provided
for each.
Form-coking is a process alternative to conventional by-product coking.
Its advantage is that it reduces the reliance on metallurgical grade coals
and, because it is essentially continuous, it is comparatively easy to operate
in an environmentally acceptable manner. Not only would form-coking reduce
emissions to air and water, but also the production of solid waste as well.
There are at least 10 distinct form-coke processes being investigated in the
United States and the rest of the world. Projections are that two or three
90
formed-coke processes will be available for adoption by the early 1980s.
Widespread implementation probably will not take place until the close of the
century.
Nuclear ironmaking and plasma arc steelmaking are two technologies in
which the thermal energy for the iron ore reduction process is applied in an
unconventional manner. In either of these processes, coal or coke would be
used solely as a reducing agent. In Japan, an eight-year research program has
recently started on nuclear steelmaking. In the United States, some work has
been done on plasma arc steelmaking, the biggest problem at present being the
large amount of power consumed in the operation (estimated to be about 2000
kwh/t).
Direct steelmaking involves the injection of a mixture of coal and iron
into a molten steel bath. Two versions of the injection process are con-
templated. In one, electrical energy for the process is supplied by an
inductor. In the second, heat is supplied by combustion of coal with oxygen
in the injection jet. Figure 25 shows the two versions. It is stated that a
91
30-ton vessel will yield up to 12 tons of raw iron per hour. This method of
ironmaking, being based on powdered coal, eliminates the need for the coke
ovens. It is also a method of producing sulfur-free fuel gas.
163
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i ROM ox IDE:
LIME
CORL.
CO,
CH3OH
iron otide.
Lime.
Figure 25. Two versions of the injection process for direct steeimaking.
164
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Powder metallurgy provides a means of producing finished steel sheet from
the compaction of iron powder. In this process, powdered steel is produced
under controlled conditions, compacted into the form of a sheet, heat treated
and then finished rolled to the final product. The process promises low
capital cost, low energy cost, and a drastic reduction in rolling mill wastes,
including solid wastes. Present-day deterrents toward the advancement of the
process are product contaminants and customer resistance.
Because the implementation of the above-mentioned processes appears to
lie well in the future, there will be little immediate impact from them on the
generation of solid wastes. There will, therefore, be no further discussion
or consideration of them in this report.
8.2.2 Processes Not Widely Used
There are three new practices that fall within this category. They are
described briefly in the subsequent paragraphs and will be covered in more
detail later on in this report.
Scrap preheating in the BOF provides thermal energy which permits scrap
to replace a portion of the molten iron. In the EAF, scrap preheating can
reduce heat time and consumption of electrical energy.
Superheating of molten iron before its admission to the BOF provides
additional thermal energy to the process and allows scrap to replace a portion
of the molten iron. This process is not used by the steel industry since
there are no installations in operation at the present time. However, the
equipment, a large induction furnace, is widely used in the foundry industry.
In cases where oil injection is used, dehumidification of the blast for
the blast furnace provides smoother operation and reduction in coke consump-
tion. Although not in use in the United States, it is currently being
practiced in Japan.
8.2.3 Processes in Substantial Current Use
There are five new processes that have made substantial inroads into
the steel industry. Each of these processes has an impact on the generation
of solid wastes. Their further and immediate implementation is anticipated.
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Burden preparation for the blast furnace consists of several stages of
sizing and screening for the raw materials prior to their introduction into
the process. All new blast furnaces are equipped for burden preparation and
many existing furnaces have been retrofitted. The effect on the process is to
provide smoother operation, reduced coke rate and reduced generation of solid
waste.
Fuel injection into the tuyeres of the blast furnace provides a means of
replacing an equivalent portion of the coke. A wide variety of fuels for
injection have been used including gases, oil, and powdered coal. The
reduction in coke usage is reflected in a reduction in emissions and wastes
from the coke ovens. Most of the blast furnaces in the United States are
equipped for fuel injection.
External desulfurization of iron is coming into wide use because it
improves the productivity, coke rate, and flux consumption in the blast
furnace. From a solid waste standpoint, in addition to reducing emissions
from coke ovens, it also provides a substantial reduction in the generation of
blast furnace slag.
Direct reduction of iron provides an alternative to the coke oven-blast
furnace route of ironmaking. At the present time, its use is more prevalent
outside of the United States than in it, there being only three relatively
small domestic installations. Direct reduction is a relatively clean process
which produces essentially only iron oxide dusts, thereby avoiding the organic
wastes of the coke plant and emissions and slag of the blast furnace.
Continuous casting to produce semi-finished steel increases product
yield, thereby reducing the generation of scrap and iron oxide wastes in the
primary mill. A secondary effect of improved yield is a reduction in the
consumption of molten iron and coke as well as their accompanying waste pro-
ducts. Approximately one-third of semi-finished steel in the United States is
produced by this method.
8.2.4 Description of Process Changes
This section will discuss each of the process changes which were listed
in Sections 8.2.2 and 8.2.3 above. The description will cover the nature of
166
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the process as well as its effect on other processes in the iron and steel-
making chain. It will also discuss its effect on the generation of solid
waste as well as the consumption of resources. Finally, there will be an
indication of the status of applications in the industry, both present and
future.
Blast Furnace Burden Preparation
The ideal burden for the blast furnace consists of lumps which are
relatively uniform in size and free of fine particulate matter. The uni-
formity creates a highly permeable bed that permits the free flow of reducing
gases. The absence of fine material not only contributes to improved perme-
ability but also reduces the carryover of particulates in the top gases and
the corresponding generation of dusts and sludges.
Creation of a suitable burden involves the crushing of lumps and the
screening of fines. The latter operation, in particular, is ideally carried
out as close to the entry of the furnace as is practical. In this manner, any
fines which are generated in previous handling operations are kept out of the
ironmaking process. All new blast furnaces will practice this technology to
one extent or another.
Another aspect of burden preparation is to produce self-fluxing sinter.
In this technique, the lime requirements of the blast furnace are furnished,
substantially in their entirety, by limestone which has been incorporated into
the sinter and calcined in the sintering process. It thereby replaces the
introducton of limestone into the blast furnace, and by virtue of reducing
calcining requirements in that unit, reduces coke rate.
In Japan, from 1955 to 1960, the intensive application of burden pre-
paration in the blast furnace reduced the coke rate from 725 kg/MT to 625
92
kg/MT. In the United States, probably one-half of the blast furnaces have
essentially complete burden preparation. It is not unreasonable to expect
that nearly all blast furnaces will adopt this technology within the next
decade.
Extensive burden preparation has a direct effect on blast furnace opera-
tions in terms of increased production, reduced generation of solid waste
167
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oxides and coke consumption. Its indirect effect lies in the coke ovens
which, having to produce less coke, yield a corresponding reduction in
emissions to air and water and in the generation of solid waste from that
process.
Fuel Injection in the Blast Furnace
The injection of auxiliary fuel through the tuyeres into the blast fur-
nace is a relatively new technology which initiated in 1961. To accomplish
fuel injection, an auxiliary circle pipe for the fuel is provided at the
vicinity of the tuyeres. Injector pipes are placed within the tuyeres,
terminating near the hearth of the furnace. The fuel that is injected through
the tuyeres replaces a part of the coke burden.
A wide variety of fuels have been injected into blast furnaces. The
replacement ratio expressed as kilograms of fuel per kilogram of coke saved
varies with the fuel injected. As a general rule, the replacement ratio for
oil or tar is 1.2:1, coke oven gas 1:1, and coal 1:0.9. In 1975, American
93
mills saved 4 million tonnes of coke while melting 8 million tonnes of iron.
This equates to 50 kg/MTHM, or approximately 7 percent of the U.S. 55 million
tonnes per year of coking capacity. At the present time, approximately 80 to
85 percent of the blast furnaces in the United States have been retrofitted to
94
handle tuyere injectants.
The newest blast furnaces being built for Bethlehem at Sparrows Point and
for Inland Steel are designed to handle 100 kg/MTHM of injectants and are
expected to operate with coke rates of 500 kg/MTHM. It will be noted that
these coke rates are almost equal to the best practice in Japan and also that
the injection rate is approximately twice the present average in the United
95
States. Within the next decade, it may be expected that nearly all of the
blast furnaces in the U.S. will be equipped for fuel injection and that the
average rate of injection will tend to double.
Injection of fuel through the tuyeres results in an endothermic reaction
at the hearth level. Therefore, it is necessary to increase the temperature
of the hot blast concurrent with the injection process. At the same time it
is necessary to provide storage for the fuel, piping facilities, control
facilities, etc. When coal is used as an injectant, facilities for pulveriz-
ing it and for avoiding explosions are also required.
168
-------
Economics provide the incentive for installation of fuel injection at the
blast furnace. The principal factor is that the auxiliary fuel is usually
considerably cheaper than the coke it replaces. Another factor is that iron-
making capacity may be increased without the necessity of providing additional
coke ovens. The environmental advantage for this process is that it reduces
the amount of coke that is produced and, along with this, a corresponding
reduction in emissions to air and water and solid waste generation. From the
standpoint of fuel conservation, if coal is used as the injectant in the blast
furnace, since it replaces 0.9 pounds of coke, it also replaces 1.4 pounds of
coal at the coke ovens.
Dehumidification of the Blast
This consists of a dry-type dehumidifier installed at the blast furnace
blower. Dehumidification provides higher combustion within the blast furnace,
lowers coke rate and increases pig iron output. The reduction in coke rate is
approximately 0.75 kg/MT of pig iron for every gram per standard cubic meter
of mositure removed. Since the mositure in the air varies with atmospheric
conditions, the reduction rate will vary as well. Under average atmospheric
conditions, the improvement is approximately 10 to 12 kg/MTHM. As indicated
in the preceding sections, reduction of coke rate in the blast furnace pro-
vides environmental benefits by reduction in output from the coke oven.
External Desulfurization of Iron
The presence of excessive amounts of sulfur in steel produces such detri-
mental effects as cracking during processing and reduced physical properties.
In order to keep sulfur within reasonable limits, generally accepted as below
0.020 percent in molten iron, it has been necessary to operate the blast
furnace with a large quantity of basic slag. In recent years, there has been
a deterioration in the quality of ore and coke which further increases slag
volume.
It is well known that a leaner, less basic slag increases productivity of
the blast furnace and increases solubility of bosh alkalies. The lean flux
rate results in a more permeable, smoother operating furnace and a lower coke
rate. The slag volume is reduced, but in contrast the sulfur content of the
iron increases. In order to achieve the advantages in the blast furnace of
169
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the leaner slag and to cope with the sulfur in the metal, a recent development,
essentially starting in 1972, is the external desulfurization of iron.
There are many desulfurizing techniques and reagents available: calcium
carbide injection, magnesium-aluminum injection, mag-coke plunging, etc. Each
technique has its advantages and disadvantages in respect to method of control,
method of operation and operating costs. All are able to effectively reduce
the sulfur content of molten iron to acceptable levels.
A blast furnace, when operating in conjunction with external desulfuri-
zation of iron, can operate with a lean slag. In a typical situation, this
type of operation results in a 10 percent decrease in slag volume, a 6 percent
decrease in coke rate, and a 37 percent decrease in flux and a 9 percent
increase in production.
The operation of the blast furnace with leaner slag and higher sulfur in
the iron results in a number of environmental advantages. The furnace opera-
tion is smoother, giving rise to fewer emission-causing slips, fewer casting
emissions, and lower slag volume. Because the coke rate is reduced, there is
a secondary advantage in regard to emissions and environmental problems in the
coke ovens. In addition, there is conservation of raw material in terms of
fluxes and coal. Figure 26 shows the sulfur balance in a typical blast
furnace in which it will be noted that 78 percent of the sulfur comes from the
coke and 15 percent"from injected fuel oil.
The process for externally desulfurizing iron involves the consumption of
reagents such as those mentioned above and the production of dust and slag.
However, these are minor in comparison to the savings in the blast furnace,
being on the order of 7 to 10 percent. On balance, the environmental effects
are definitely on the positive side.
A number of methods are available which are easy to operate and which
insure positive control of sulfur levels in the iron. One method, as shown in
D
Figure 27, consists of loading a plunger with Mag-coke and dropping it into a
ladle which is filled with molten iron. Plunging time is about 15 minutes.
Another method (Figure 28) involves the pneumatic injection of the reagent
through an injecting lance into the molten iron. The carrier gas for the
reagent is an inert gas such as argon or nitrogen. In both methods, it will
be noted that a baghouse is provided for the collection of emissions,
170
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total input: 4.64kg S/l hot metcl
figures in kg 5/t hot metal and % of the total input
burden 0.34kg-(7.^%)
I
oil
0.68kg (14.6%)'
slag
4.16kg (89.5%)
coke
3.62 kg (78.0%)
balance deficit
-0.22 kg (4.8%)
-—flue dust
0.02 kg (0.5%)
hot metal
0.24kg (5.2%)
Figure 26. Sulfur balance for a typical blast furnace.
171
-------
10
I. Plunger
2. Hot metal ladte
3. Hot meto! ladle cor
4. Slog pot
5. Slag sklrnmer
6. Dust collecting food
7. Pit
8. Torpedo car
9. Rail for torpedo car
10. Plungej transport car
I. Pit
2. Roll for Torpedo cor
3. Pulpit
4. Plunger Transport cor
5. Dust collecting duct
6. Plunder changing cor
7. Storage yard of plunger
8. Jib crcn» for plunger
9. Bog filter
8
-B-
•e
11
6^
n
04
w
Figure 27. Ground plan of Mag-Coke desulfurizing plant
172
-------
(D Desulphurizing agent storage tank
© Desulphurizing agent injection tank
(D Reaction aid storage tank
© Carrier gas piping
Injecting lance
Dust collector
Torpedo car
Figure 28. Schematic representation of the desulfurizing facilities of the torpedo top-injection method.
-------
Interest in external desulfurization of iron is rapidly increasing because
of its ability to improve iron composition and to reduce operating cost. There
is no doubt that the coming decade will see substantial introduction of this
method in the steel industry.
Direct Reduction of Iron (DRI)
In the United States, the principal direct reduction process is the
Midrex. Figures 29 and 30 show schematic flow diagrams of this process. In
it, the oxide feed which is normally lump ore and unreduced pellets flows
continuously down through the reduction furnace. The reformed gas has the
following approximate composition: 73 percent hydrogen, 16 percent carbon
monoxide, 7 percent carbon dioxide, and 4 percent methane. It reacts with and
reduces the iron oxide in the reduction furnace. The reduced iron has about 92
to 93 percent metallization and 1 to 1.4 percent carbon.
There are other direct reduction processes on the North American Continent.
The HyL process also uses reformed gases. Unlike the continuous process
previously described, it is a semi-batch process in which the ore is contained
in fixed beds with a multiple number of reactors. Another process is the SL/
RN process in which carbonaceous material is mixed with the iron oxide material
to form pellets. After preparation, the pellets flow through a rotary kiln
reactor and then to a rotary cooler from which they are discharged to magnetic
separation facilities. For all of the processes mentioned above, there is
emissions control from material handling by means of baghouses and from the
circulating gas by means of scrubbers.
In general, the quantity of emissions and wastes produced by DRI are low
in comparison to other metallurgical processes. The quantity of dust and
sludge is approximately 3 to 6 percent of the feed material. In most plants
this is too small for economic recycling and the dusts and sludges are either
landfilled or sold to other users.
The reduced pellets, also called sponge-iron, is generally used as charge
material for the EAF where it replaces scrap. The result of this replacement
is increased consumption of electricity. However, this is balanced by increased
yield, increased productivity, and reduction in residual elements in the
finished product. There is also an increase in the slag volume as compared to
174
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10 »o"-«»ce
Sf»L IECS
ljSt»l Ct!
BIOWEB
I E9LU**e
DT
I ICAS
ft-
MJ.N BU'NEHS
V
1O»CiS
SCKUSSEH
H.-O cJ
• PROCESS NlTU«<»lC»S
-PROCtSS N1TUB41CAS
PXOCFSS
«f atSSOXS
82 MTPH
IJUD
EEI
I
oEK«TOI«
BEFOBMfO C»S P|
RE»CWW£0
c.»s
coot IK
1
— -
p
r
«v
REDUCTION '
FUMNACE
t
MOUCIOMQOUCI
58 MTPH
Figure 29. Schematic flow diagram of the Midrex Process.
(Iron and Steel Engineer, September 1978)
95
Figure 30. Flowsheet of the Midrex Process.
(Iron and Steel Engineer, September 1978)
175
96
-------
all scrap practice, the value being approximately equal to that from the BOF.
Typical values are shown in Table 72.
TABLE 72. USE OF DIRECT REDUCED PELLETS IN EAFs
1.
2.
3.
4.
5.
6.
Feed scrap, %
Feed pellets, %
Energy used by furnace kwh/t
Yield of steel, %
Productivity
Residuals, %
100
0
541
87.9
Base
0.46
70
30
575
89.5
+8.3%
0.57
40
60
604
92.6
+7.8%
0.27
20
80
635
92.2
-2.2%
N/A
At two installations in Japan, a process similar to the SL/RN is used for
recycling iron oxide wastes which are recovered in pollution equipment else-
where in the steel works. The Japanese report no problem with the presence
of zinc or lead and they also indicate that at least part of the product is
used as feed for the blast furnace where it results in increased productivity
and reduced consumption of coke. Reported values are an 8.2 percent increase
in production and reduction in coke consumption corresponding to a 10 percent
addition of reduced pellets to the burden.
In the integrated production of steel from iron ore, the direct reduction/
EAF route has the following environmental advantages in comparison to the
conventional coke oven-blast furnace route.
1. DRI eliminates the need for coke ovens and all the
environmental problems associated therewith.
2. Control of DRI emissions is relatively easy to accomplish.
3. The slag production from DRI comes solely from the EAF.
All of the slag from the blast furnace is eliminated.
4. DRI may be accomplished by a wide variety of fuels, thereby
avoiding dependency on metallurgical coals.
Direct reduction of iron ore is practiced more widely on other continents
than in North America (Table 73). There are only three installations in the
U.S. and their total production amounts to somewhat less than 1 million tonnes
176
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TABLE 73. DIRECT REDUCTION INSTALLATIONS IN NORTH AMERICA
ANNUAL OUTPUT MT
Process Name Location United States Other
Hoskin
Midrex
Accar
HyL
Hogannas
SL/RN
Rockwood, TN
Georgetown Steel
Oregon Steel
Sidbec-Dosco, Can.
Sudbury, Ont. Can.
HYLSA lM)-Monterey, Mex.
HYLSA 2M) -Monterey, Mex.
HYLSA 3M) -Monterey, Mex.
TAMSA- Veracruz, .Mex.
HYLSA(lP)-Puebla, Mex.
HYLSA(2P)-Puebla, Mex.
New Jersey
Stelco, Can.
90,000
410,000
410,000
>1, 000, 000
340,000
95,000
270,000
450,000
235,000
315,000
700,000
70,000
520,000
TOTALS 980,000 3,925,000
per year. Thus, it accounts for approximately 0.8 percent of the ingot tonnage
in the United States.
The development of DRI has taken place primarily in those parts of the
world where natural gas is plentiful and cheap and coking coal is essentially
absent. Table 74 provides a listing of some of the key factors that affect
the development and implementation of DRI. The first column lists those
factors that are impeding the development and the second column those which
are promoting it. With the passage of time, the impetus to DRI will increase
primarily due to the impact of lower capital costs and to the development of
DRI processes which will use coal in preference to natural gas as the fuel.
Table 75 shows direct reduction plants and plans world wide. It will be noted
that North American capacity is expected to triple by 1985.
177
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TABLE 74. IMPLEMENTATION AND DEVELOPMENT OF DIRECT REDUCTION (PR) PROCESSES
Impeding Factors Promoting Factors
1. Steel industry conservatism
2. High development costs
3. Limit and cost of natural gas
4. Low scrap prices versus DR iron
5. DR iron requires more power than
scrap in EAF
6. DR iron has higher gangue—leads
to high slag in EAF and higher
loss of FE
7. Not all ores are suitable for DR
1. DR/EAF route has lower capital
cost than CO/BF/BOF route
2. DR iron produces lower residuals
and faster heats in EAF than
scrap EAF
3. - DR/EAF has minimal environ-
mental impact compared to CO/
BF/BOF
TABLE 75. REGIONAL DISTRIBUTION OF DIRECT REDUCTION PLANTS AND PROJECTS
(Thousands of tonne/vrV*"
1954 to 1975 1976
Region
North America
Latin America
Western Europe
Eastern Europe
Middle East
Africa
Asia
Oceania
World, total
tonne
1970
2400
810
—
—
1150
1194
120
7644
% tonne
25.8 2210
31.4 3130
10.6 850
— —
— • —
15.1 1150
15.6 1344
13 120
100 8804
%
25.1
35.5
9.6
—
—
13.1
15.3
1.4
100
1977 1978
tonne
2935
4825
850
—
3015
1450
1834
120
15029
% tonne
193 2935
32.1 5345
5.7 1650
— —
20.1 4415
9.6 1700
12.2 2409
0.8 120
100 18574
%
15.8
28.8
8.9
—
23.8
9.1
13.0
0.6
100
1979
tonne
2935
8645
1650
2500
4415
1700
4134
120
26099
%
11.3
33.1
6.3
9.6
16.9
63
15.8
03
100
1980 198110
tonne
2935
9065
3650
5000
4415
1700
4134
120
31019.
% tonne
9.4 64S5
29.2 15035
11.7 5700
16.1 5000
14.2 8715
5.5 5100
133 4194
0.4 1520
100 51720
1985*
%
12.5
29.1
11.0
9.7
16.8
9.9
8.1
2.9
100
Distribution by number of installations
North America
Latin America
Western Europe
Eastern Europe
Middle East
Africa
Asia
Oceania
World total
8
8
7
0
0
2
8
1
34
233 9
233 10
20.6 8
— 0
— 0
53 2
233 9
3.0 1
•100 39
23.1
25.6
20.5
—
—
5.1
23.1
2.6
100
11
14
8
0
3
3
11
1
51
21.6 11
27.4 16
15.7 9
— 0
5.9 5
5.9 4
21.6 12
1.9 1
100 58
19.0
27.6
153
—
8.6
6.9
20.7
1.7
100
11
18
9
1
5
4
13
1
62
17.7
29.0
143
1.6
8.1
6.5
21.0
1.6
100
11
19
11
2
5
4
13
1
66
16.7 16
28.8 33
16.7 15
3.0 2
7.6 9
6.0 9
19.7 14
13 3
100 101
15.8
32.7
14.8
2.0
8.9
8.9
13.9
3.0
100
178
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Preheating Scrap for Steelmaking
Scrap preheating is practiced to a limited extent for steelmaking, both
in the EAF and BOF, In the former case, the preheating, is accomplished by the
combustion of fuels in a unit external to the steelmaking furnace. It, there-
fore, serves to reduce meltdown time, consumption of electrodes, and consumption
of electric energy, in this application, preheating has little or no environ-
mental effects.
In the BOF, scrap preheating is accomplished in the vessel. Fuel, either
oil or natural gas and oxygen are delivered to the furnace from nozzles of an
auxiliary lance. Combustion takes place raising the scrap temperature to red
heat. This method of scrap preheating takes time in the furnace and reduces
productivity. However, the thermal energy provided in scrap preheating
permits greater utilization of scrap. In the BOF under normal practice the
metallic charge is approximately 30 percent scrap and 70 percent molten iron;
under scrap preheating, the ratios are 40 and 60 percent.
Scrap preheating in the BOF produces essentially no increase in emissions
or solid waste as compared to the conventional practice without preheat.
However, it does reduce the amount of molten iron which is consumed thereby
providing a corresponding reduction in the quantity of emissions and discharges
from both the blast furnace and the coke oven.
The main impetus for extension of this practice in the BOF comes from
consideration of iron production. If a plant is deficient in blast furnace
capacity and if there is extra time available in the BOF, scrap preheating
provides an inexpensive way to achieve more steel production. On the other
hand, if the BOF does not have the extra time for preheating, it may be more
desirable to achieve increased steel production by some other method of
increasing ironmaking capacity. Because of these conflicts, it is expected
that the implementation of scrap preheating in the BOF will proceed at a
moderate pace over the next decades.
Superheating Molten Iron for the BOF
Superheating of molten iron is performed in a furnace which resembles a
hot metal mixer. In the lower region of the furnace, jet-flow inductors
179
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provide the necessary heat to increase the temperature to any desired level up
to 2900°F. The furnace and the 60-Hz inductors have been used extensively for
heating molten iron in foundries.
Superheating molten iron serves the same purpose as scrap preheating;
that is, to expand the capabilities of existing BOPs without building new
blast furnaces or coke ovens. However, it has the advantage in comparison to
scrap preheating, that it does not increase furnace cycle time and, therefore,
does not reduce productivity of the BOF.
Table 76 shows hot metal, scrap, and other metallic quantities per ton of
raw steel under various conditions. In conventional BOP practice (Column A)
molten iron comprises about 70 percent of the charge along with 30 percent
scrap. If hot metal were superheated 400°F, the added energy would permit
melting of about 20 percent more scrap as supplemental coolant, up to about 40
percent of the steel mleted (Column C). The table shows other alternatives
such as pre-reduced pellets (Column B), cold pig iron (Column E), etc.
TABLE 76. EFFECT OF SUPERHEAT ON TYPICAL BQF MATERIALS BALANCE AND PRODUCTION
97
Superheat temp. , °F
Charge-T/T raw steel
Hot metal
Scrap
Cold metal
Pellets
Total metal! ics
Steel production rate
% Base
% Maximum
Base
___
(A)
0.809
0.340
—
—
1.149
100
84
SUPPLEMENTAL COOLANT
Pellets
& Cold
Pellets Scrap Metal
400
(B)
0.791
0.333
—
0.025
1.149
102
86
400
(C)
0.732
0.408
—
—
1.140
110.5
93
400
(D)
0.732
0.308
0.100
0.012
1.153
110.5
93
Metal
400
(E)
0.681
0.287
0.186
—
1.154
119
100
180
-------
The advantages claimed for superheating molten iron are that it provides
added steelmaking capacity at low cost, it improves scheduling in the BOF and
provides a buffer for smoothing out variations in iron composition. At the
present time,.there are no installations of this technology which operate in
conjunction with the BOF. However, it is widely used in iron foundries and is,
therefore, considered proven technology. It is expected that the advantages of
this practice will result in its acceptance by the steel industry, the rate of
acceptance being impeded by that industry's traditional conservatism.
Replacement of Open Hearth Furnaces
In 1977 (see Table 14, Section 6.2.1) the production of steel from the
open hearth accounted for approximately 16 percent of the steel output in the
U.S. It is expected that this production will gradually diminish over the
next two decades due to environmental pressures and operating cost disadvan-
tages in respect to the BOF which would replace it.
The principal environmental problem for the more modern open hearth fur-
nace is the extreme difficulty of controlling fugitive emissions from the
furnace during the various stages of charging, melting, refining, and tapping.
The cost disadvantages result primarily from the multitude of open hearth
furnaces in a typical installation in comparison with the highly controlled,
highly productive BOF. Nevertheless, the rate of replacement is bound to be
gradual because the more modern open hearth furnaces are relatively efficient
and their replacement cost is becoming greater all the time.
The BOF produces less slag (minus 40 percent) and more iron oxide particu-
lates (plus 50 percent) per ton of steel than does the open hearth furnace.
In 1977, if all of the open hearth capacity had been replaced by BOF capacity,
the change in production of solid waste would have been a slag reduction of
1930 tonnes and an increase in iron oxide of 130 tonnes.
Continuous Casting
There are two methods of producing semi-finished product in operation
today. One is to pour the steel into ingot molds, strip the ingots from the
molds, reheat them in soaking pits and roll them on a primary mill. The other
is to pour the steel in a water-cooled copper mold that is open at the top and
181
-------
bottom. The shape of the mold is such as to directly produce the semi-finished
product which is withdrawn continuously from the open bottom.
The quality of continuously cast steel is equal to that of conventionally
made steel, and often better. The yield of the semi-finished product as
compared to the ingot route is higher, the manhour requirements are lower, the
energy requirements are significantly reduced and the use of plant space is
more efficient.
Because of these advantages, continuous casting has been making inroads
into steelmaking technology. Starting with the first U.S. installation in
1962, by 1969 U.S. production was 4.5 million tonnes of continuous cast steel
and by 1978, 28.4 million tonnes. It is estimated that there is a potential
go
for continuous casting in the U.S. of about 75 million tonnes. It is not
unreasonable to project that nearly all of this capacity will be provided
within the next two decades.
The yield of semi-finished steel from molten steel varies depending upon
the nature of the final product whether slab, bloom, etc. On the average, the
yield from continuous casting is 94 percent, and from the ingot route 81
percent. The scrap loss in the ingot route is 13.5 percent and in the con-
tinuous casting route 5.1 percent. The loss in terms of scale and sludge are
5.2 percent and 0.8 percent, respectively. The latter change is particularly
significant since a portion of scale and sludge is landfilled or dumped and
thus irrevocably lost to the steelmaking process.
The environmental advantages of the continuous casting route in terms of
reduced emissions to air and water and reduced solid waste generation go
beyond the immediate process itself. Because the molten steel is used more
efficiently, to produce the same volume of finished product, less steel needs
to be made in the steelmaking furnace, less iron in the blast furnace, and
less coke in the coke plant. Each of these changes has its own environmental
benefits.
8.2.5 Effect of Process Changes on the Model Plant
In the previous section, descriptions were provided for various process
changes that affect the generation of solid waste and the utilization of
resources. In order to quantify the potential effects and to put the value of
182
-------
the changes in proper prospective, it is necessary to incorporate them in the
model plant of Section 6.0.
The model plant of Section 6.0 provides information on the generation of
solid waste from a production of 2,500,000 tonnes of steel per year. In this
plant the production of semi-finished steel is 2,140,000 tonnes per year. In
order that a fair evaluation of the process changes be made, and because some
of the changes reflect variations in yield, the production of semi-finished
steel has been held constant. The production figures from the various units
preceding this point were then derived by working backwards through each of
the processes. In the various diagrams which follow there are two values of
quantity shown for each item. The value without parentheses is the original
value before implementation of the process change; the value in parentheses is
after the process change.
The results which are shown in the diagrams must be treated with caution.
The quantities shown derive from a number of simplified assumptions. They
ignore the complications that pertain to implementation of process changes in
existing facilities where, for example, an otherwise desirable change is
impeded by existing technology, space limitations, lack of capital, company
conservatism, etc. Despite the caution, the results do indicate that the
process changes have the capability of making substantial reductions in the
generation of solid waste and that they deserve further investigation.
Analysis of Process Changes
Each of the process changes described in the preceding section will be
inserted into the model plant and its effect on resource consumption and solid
waste generation will be analyzed.
Figure 31 shows the effect caused by further implementation of continuous
casting. The assumption is made that semi-finished steel produced in this
manner will essentially double and thereby provide two-thirds of the product.
The effect on input of molten steel is to reduce the quantity by 4 1/2 percent.
The reduction is distributed on a percentage basis between the BOF and EAF.
The amount of scrap produced is reduced by 71,500 tonnes and this is reflected
in the charge to two melting units.
183
-------
Water
(1,590.000)
840,000
BO F Steel
2,000,000
(1,900,000)
CO
EAF Steel
Steel
2,500,000
(2,390,000)
500,000
(490,000)
(800,000)
1,660,000
Continuous
Casting
43,000 Scrap
(87,011)
Recycle Water
(1.490,000)
790,000
Scale Pit
Filter
(150) ,r
• Effluent
20.5 Solids
(38.6)
6,900 Scale (recycled or stocked)
(12,800) Water
80 Sludge
(90% landfilled)
Water
Recycle
Primary
Rolling
(11,600)
23,400 Soaking
Pit Scale
(landfilled)
(107,975) jr
223,450 Scrap
Cropcnds
(650,000)
1,350,000
240,000 Safes,
Transfers
Shapes
2,140,000
1,900,000
"""To Hot Rolling
Oil Skimmer
(1,200)
2,500 Sludge
(95% tandfitled) (28,200)
60,600 Scale
(recycled or stocked)'
-Effluent
Scale Pit
Filter
» 1
bU solids
i -,1251 .,
(oil recovered,
recycled)
i
Figure 31. Continuous casting, soaking, primary rolling material flow in production of 2,500,000 tonnes of steel per year
(all numbers in tonnes).1 & (numbers in parentheses represent results of process changes)
-------
Figures 32 and 33 show the material flow to the EAF and EOF, respectively.
In these units, pre-reduced pellets make up the scrap deficit, the ratio of
pellets to scrap being the same in both units. In the EAF, other changes in
dust and slag are ratioed to the steel output. In the .EOF the situation is
more complicated in that not only is this ratio taken into account but also
the effect of scrap preheating and superheating of molten iron. These last
two cause the ratio of hot metal to total metal!ics in the charge to drop from
70 to 56.4 percent.
In Figure 34, the reduction in iron requirements reduce the demand for
materials in the blast furnace and the production of wastes. In addition, the
quantity of slag is reduced another 10 percent in response to the introduction
of external desulfurization. Further, the coke requirements are estimated at
500 kg/MTHM which assumes substantial implementation of burden preparation, a
high rate of fuel injection and dehumidification of the blast throughout the
industry.
Figure 35 shows the effect on coke oven operations that takes place as a
result of the reduction in coke requirements. The amount of coal required,
the by-products and waste produced all vary in proportion to coke output.
Figure 36 combines all of the process into one model plant. The combined
effect of the various process changes becomes evident. There is substantial
change in the quantities of resource material that is required and wastes that
are generated. These are analyzed in the next two sections.
Analysis of Resource Consumption
Table 77 provides a summary of the amount of resource material as well as
solid waste generation that is required both before the process changes are
initiated and after they take place. In addition, there are two columns which
show the difference in material requirements, both as actual tonnes per year
and as percent of initial requirements. All of the quantities are taken from
the data in Figure 36.
The iron ore quantities include charge material from the blast furnace as
well as that for direct reduction. There is a slight increase in ore con-
sumption (2 percent) which results from the introduction of direct reduction
less the cumulative effects of continuous casting, scrap preheating, and
superheating of molten iron. On the other hand, the quantity of scrap consumed
185
-------
(137)
140 DUST
TO AIR
DRY
SYSTEM*
(337.000)
(173,000) Pre-reduced Pellets
45.640 FLUX
(51.237)
(6,400)
" 6,500 DUST (landfilled)
FUME
ELECTRIC
ARC
FURNACE
(490,000)
-*»500.000 STEEL (to shaping operation)
(64,700)
60,000 SLAG
(iron recovered, balance landfilled,
10% other uses)
•Nationally, 76% dry systems
15% wet systems
9% semi-wet systems
Figure 32. Electric arc furnace material flow in production of 500,000 tonnes of steel per year (all numbers in tonnes).
(numbers in parentheses represent results of process changes)
186
-------
(227,000)
250,000 OFF-GAS
200 DUST
(190)
CD
(1,180,000)
1,600,000 Hot Metal-
(613,000)
499,000 Scrap
(299,000) pellets
292,221 Flux
(170,210)
190,000 Oxygen
(180,000)
Basic
Oxygen
Furnace
Water
WET*
CLEANING
SYSTEM
(1,900,000)
-^2,000,000 STEEL
(276,000) T
290,000 SLAG
(iron recovered; estimate
50%used, recycled)
Settler
Thickener
(39,000)If
41,000 SLUDGE
(50%landfilled, balance stocked
or recycled)
Water Recycle
Effluent
*21 Solids
(20)
•Nationally, 19% dry systems
61% wet systems
20% semi-wet systems
Figure 33. Basic oxygen process material flow in production of 2,000,000 tonnes per year of steel (all numbers in tonnes).16
(all numbers In parentheses represent results of process changes)
-------
Water
(3,000,300)
4,153,600 Top Gas + Dust
High Energy
Wet Scrubber
(18,700)
25,400 DUST-
(recycled to sinter)
Dust
Collector
00
00
691,000 Sinter
1.970,000 Ore, Pellets •
(1,276,000)
128,000 Fluxes-
(00,000)
900,000 Coke -
(590,000)
2,647,000 Air Blast
(1,952,000)
Top Gas
•(•Dust
Blast
Furnace
(370,000)
-*-557,000 SLAG
Settler
Clarifier
(Treatment)
Filter
Water Recycle
(2,970,245)
•»• 4,113,524 Top Gai (to stoves, boilers)
34 Dust
(25)
^Effluent
*42 Solids
(30)
(used as aggregate, cement, ballast)
(30.000)
40,000 SLUDGE
(5,000 landfill; 35,000 recycled
to sinter or stocked)
(1,180,000)
1,600,000 Hot Metal
(to steelmaking)
Figure 34. Blast furnace material flow in production of 2,500,000 tonnes of steel per year (all numbers in tonnes).16'18
(numbers in parentheses represent results of process changes)
-------
(3.700)
5,700 Uncontrolled Particulate
Emissions
(138.QQO)
210,000 Coke Oven Gat (to coke oven underfiring, sinter plant, etc.)
(831.842)
1,268,343 Coal
00
<£>
(21,000)
32,000 Breeze
(recycled, sold)
Oleum Wash Wast*.
Neutralization
Waste*
(360)
540 Still Lime Sludge
(iandfilled)
(360)
540 Tar Tank Sludge
(landfilled)
900,000 Cake
(to Blast Furnace)
(590,000)
•Quantity unknown, from light oil refining operation.
Biological
Treatment
Plant
(1.000) *
1530 Sludge
(landfilled)
(47,300)
72.100 Product!
(Tar, Sulfata, Light OH)
(30,100)
4 5,900 Water From Coda Oven
Final Efiluent
33 Solids
(22)
Figure 35. Material flow lor coke plant in production of 2,500,000 tonnes of steel per year (all numbers In tonnes).
-------
(732.000}
Iron Oxide
(1.720)
2610
Organic Sludge
(21.000) _
32.000 Breeze
(1,276.000)
1.970.000 Iron Oxide
(29.500)
40.000-*
Sludgt
(39.000)
41,000-*
Sludge
(138,000)
210.000 Coki
Oven Gas
• (21.200) Dust
(14,500)
14,500 Dust
(18.700)
*~ 25.400 Dust
*• 6.500 Dust
(6,400)
*
290.000
Slag
(276.000)
(150)
80 Sludge-*
(1.200)
2.500 Sludge -*
240.000 Sales -*-
3.100 Sludge * — —
(490,000)
,, 500.000 Steel
2,500.000 Steel
(2,390,000)
Continuous Casting
Primary Rolling
(12,800)
- 6,900 Scale
2,140,000 Steel (2.140.000)
43,000 Scrap (87,000) (29200)
*• 60.600 Scale
(11.600)
»- 23.400 Soaking Pit
Scale
(108.000)
-*- 223,450 Scrap
1.900,000 Steel
Hot Rolling
1,098.000 Sales -*-
140.000 (Wet)-
Sludge
110 Sludge •
32.900 Scale
- 62,360 Scrap
1.801,200 Steel
\ 703,200 Steel
Pickling
Cold Rolling
475,000 Sales -*-
1.400 Sludge -*-
530 Sludge -*-
40 Scale
700.000 Steel
Galvanizing
Tin Plating
-*- 125,000 Galvanized Product
•*• 100.000 Tin Plated Product
Rgure 36. Waste production from typical plant with 2,500,000 tonnes of steel per year (all numbers in tonnes).
(All numbers in parentheses represent results of process changes.)
190
-------
TABLE 77. EFFECT OF PROCESS CHANGES
Model plant to produce 2,140,000 tonnes annually of
semi-finished steel
Consumption of
Resource Material
ANNUAL QUANTITIES-1000 TONNES/YR
Before After
Change Change Difference
Difference
Coal
Iron ore
Fluxes
Scrap
Coke gas produced
Light oil produced
Solid Waste Generation
Organic sludge
Iron oxides - total
Dust
Sludge
Scale
Slag - total
Ironmaking
Steel making
Scrap
1268
1970
466
499
210
72.1
2.6
257.5
46.4
87.3
123.8
907
557
350
328.8
832
2008
281
613
138
47.3
1.7
220.9
60.8
73.6
86.5
710.7
370
340.7
257.4
436
-38
185
-114
72
24.8
0.9
36.6
- 14.4
13.7
37.3
196.3
187
9.3
71.4
35
- 2
39
-23
35
35
35
14
-31
16
30
22
34
3
22
increases by 23 percent as a result of these same factors, continuous casting
acts to reduce scrap while the other two factors increase it. The additional
scrap is assumed to be available from purchases in the scrap market. Any
shortfalls in this area would have to be made up by the additional production
of reduced pellets from iron ore. The reduction in fluxes derives from the
reduction in steel requirements which take place in continuous casting. How-
ever, the largest reduction takes place in the blast furnace because of the
widespread introduction of external iron desulfurization. The reduction in
191
-------
coal essentially reflects the cumulative benefits of process changes which
were introduced in the blast furnace, BOF, and continuous casting.
Listed under resource material are the by-products produced in the coking
operation. The principal ones, coke oven gas and light oil, are reduced in
production by the same percentage that applies to the reduction in the con-
sumption of coal. They are considered resource material because they supply
energy that otherwise might have to be furnished from another source.
Analysis of Solid Waste Generation
The reduction in the generation of solid waste as a result of the process
changes previously described follows a similar pattern to the reduction in the
consumption of resource material. The generation of organic sludge, for
example, drops by the same percentage as does the reduction in coal consump-
tion. A similar comparison exists between total slag and fluxes. Iron oxide
wastes drop by a somewhat smaller percentage than the previous factors.
In regard to scrap, there is a substantial change that occurs. Before
the initiation of the process changes the amount of scrap consumed exceeds
that produced by 170,000 tonnes. After the process changes are in place, the
difference increases by 2 times to 355,000 tonnes. In order to achieve
balance, much more scrap will have to be purchased under the latter condition
than under the former. On balance, this is undoubtedly a positive environ-
mental factor because it will provide incentive for increased efforts in the
recovery of scrap and in the regulations of its export.
The process changes also create another positive environmental effect in
regard to solid waste generation. As will be noted on Table 77, the generation
of the waste in the form of sludge decreases by almost the same amount as the
increase in dust generation. Since dust is generally easier to handle than
sludge and since its handling does not incur the water pollution problem that
accompanies sludge handling, environmental degradation will be reduced.
8.2.6 Future Iron and Steelmaking
The iron and steel plant of the future may incorporate radically new
technologies for producing steel. A method for producing the molten steel
directly from iron oxide, coal, and oxygen has been proposed and described
192
-------
earlier in this report as well as shown in Figure 25. There was also dis-
cussion of powder stripmaking in which the molten steel is converted to a
powder which is compacted and rolled into sheet steel. These two technologies,
in combination, would offer reduction in the physical size of the plant, its
capital and operating cost and the environmental effects. It is relatively
easy to visualize how these processes may be essentially closed to prevent
emissions to the atmosphere, and how they may reduce solid waste generation.
As noted before, the implementation of these and other technologies will
probably not take place until the next century. It would certainly be of
benefit to the steel industry and to the environment if the Federal Government
were to provide incentives for their development.
There is one case where the steel plant of the future appears to be under
DO
construction today in Pittsburgh. This is a plant designed to produce 20 to
25 TPH of light product such as rebar, rounds, and other merchant products.
Figure 37 shows a diagram of the process. In it, scrap is charged to an
EAF from which the molten steel is poured into an 8 foot wheel-belt caster.
From the casting machine the semi-finished bar proceeds through a 14-stand
rolling mill, a looper, and a cooling conveyor. Figure 38 shows the section
for the as-cast billet, the intermediate shapes and the finished round. The
remarkable feature of the mill is that the entire facility, including melting,
casting, and rolling takes place within a space of about 200 square feet.
8.3 NEW DIRECTIONS SUGGESTED BY RECENT U.S. PATENTS
The patent classes and subclasses that were searched for this discussion
are as follows.
Class 65 Glass Manufacturing
/19 Slag utilization
Class 75 Metallurgy
/3 Beneficiation of ores by agglomeration
/4 Beneficiation by coking
/5 Beneficiation by sintering
/24 Pyrometallurgy, treating slag
/25 Pyrometallurgy, treating flue dust
/30 Pyrometallugy, iron/steel slags
193
-------
-SCRAP
HOPPER
A ELECTRO-MELT
FURNACE(20-25TPH
r£rt / (20-25 TPH)
LADLE TRANSPORT -
STRAND CONDITIONING
SECTION INTS>—>^
r PINCH ROLL WITH
\ FLYING CUT-OFF
\ r-
COOLING CONVEYOR-
LOOP LAYER
WATER SPRAY-,
EXHAUST FAN
8-8—8-8-8-8-
8 FT WHEEL
BELT CASTER
COIL DROP AND
COLLECTOR CAR
BELT REELS AND
COOLING LINE
99
Figure 37. Melt shop, caster, rolling mill layout for 100,000 ton per year facility.
(Iron and Steel Engineer, September 1978)
2"8
J
6.0 SO M 4.5 SO IN -
I VERTICAL PASS 2. 45* PASS 3. 45° PASS
(SQUARE SHAPE) (DIAMOND SHiPE (SQUARE SHAPE
= 8 SO IN
(AS CAST- SO SO IM '
L
45 SO IN
3 375 SO IN
1 VERTICAL PASS Z HCS'ZCMa.L °ASS 3. VERTICAL "ASS
(SQUAPE SHAPE) (OVAL SHAPE! (ROUWO SHi=E
Figure 38. Cast billet, intermediate shapes, and finished round.
(Iron and Steel Engineer. September 1978)
S3
194
-------
Class 423 Inorganic Chemistry
/1 38 Recovering iron group
/1 39 Recovering by ion exchange
/1 40 Recovering by precipitation
8.3.1 Blast Furnace Slag
This stream comprises waste oxides from the ore and the coke, with lime
and magnesia to lower its melting point and take up sulfur. The ratio of slag
to molten iron product has trended downward; one reason is the increased
quality of beneficiated ore pellets, and another is reduced coke consumption
made possible by oxygen and/or fuel additions through the tuyeres. Super-
fluxed sinter has had a small additional impact.
"External desulfurization" is a process improvement which would further
reduce the volume of slag. The concept is hardly new, but new materials or
methods may spur its adoption. Thus Turkdogan advocates desulfurization in a
first blow in the BOF, and Yoshida recommends oxide-coated magnesium parti-
cles.106-107
If the slag is poured into a pit and allowed to cool slowly, it is diffi-
cult to break up and use. Jablin has proposed dry quenching with heat recovery
108
in a waste heat boiler. But most quenching is with water, and this generates
H2S and a runoff of contaminated water. At least one local control agency
(Allegheny Co., Pennsylvania) requires the abatement of this nuisance, and
several patents have resulted. Some seek to prevent the emission by adding
reagents to the quench water: bases or carbonates, oxidizing agents, and
llect
1 nq 1
ferrous salts, e.g., waste pickle liquor. Others seek to collect the
HgS and oxidize it to by-product sulfur or to water-soluble anions.
Water quenching shatters the slag and produces more surface and more H^S; a
gentler quenching with air, possibly enriched with oxygen, might be presumed
to freeze in most of the sulfur and oxidize that little which appeared at the
surface.
In addition to the well-known uses for blast furnace slag, it can be used
119
to stabilize the sludge from lime or limestone scrubbing of flue gases.
195
-------
8.3.2 Steelmaking Slags
In many cases these have been recycled to the blast furnace to recover
iron values. Zinc oxide is added to the slag by the process outlined in the
Kreiger patents and may cause problems in recycling the slag to the blast
104 105
furnace. ' The change in composition of BOF slag, for example, is not
large, and a reducing blow in a separate vessel could make it acceptable for
immediate recycle to the converter; the slag from an occasional blow might
have to be purged.119'120
8.3.3 Blast Furnace Dust and Sludge
Blast furnace dust is routinely recycled to the blast furnace by way of
the sinter plant; the sludge, being fine and wet, presents a problem. Since
some water is necessary in the sinter mix, judicious dewatering of the sludge
permits it to be the source of that water. Alternatively, the sintering
121
process may be managed in such a way as to be more tolerant of wet solids.
But there is no doubt that the finest blast furnace dusts and sludges
require special handling when used for sinter feeds, and various other means
of agglomerating such material to form blast furnace burden have been commer-
cialized over the years. Lime, portland cement, and coal tar pitch are well-
122
known binders, but some thermal processing or at least aging is required.
A novel bonding agent is formic acid in aqueous solution; some heavy metal
122 123
oxides dissolve briefly and then re-precipitate as a gelatinous binder. '
More aggressive thermal treatments, as in rotary kilns, typified by the SL/RN
process, are offered commercially. Some of these merely coke the iron oxide
and some go as far as direct reduction.
In the current view none of these processes is economical when applied to
waste oxide reclamation. But if they were operated at the scale of a formed-
coke plant, the view might be entirely different. Thus a plant operated
according to an FMC patent admixes a judicious amount of water with the coal
124
char; clearly this water could contain iron oxide fines. Incorporating dry
125
iron oxides was contemplated in an earlier FMC patent. The problem with
this method of recycling iron oxide wastes is that, under the reducing con-
ditions which exist in the coke ovens, the sulfur in the coal would react and
196
-------
combine with the iron oxide, thereby adding to the sulfur burden in the blast
furnace. This is undesirable.
A PECOR patent discloses that dry or dried waste oxides can be entrained
i ?fi
into a blast furnace or Q-BOP through the tuyeres. The expectation is that
most of the recycled material would be incorporated into the metal or the
slag; any which escaped would serve as condensation nuclei, making the emitted
particulate coarser and thus easier to collect.
The finest blast furnace particulate is a nuisance when collected wet or
dry. The former is the conventional choice. But two novel processes collect
and chemically modify the solids. A patent assigned to Republic Steel dis-
closes that a hot gas stream containing carbon monoxide and iron values should
be passed through a bed of granular lime; metallic iron and dicalcium ferrite
107
(2CaO ' Fe203) are formed. Such a product is suitable for recycle to the
blast furnace. A patent held by Kaiser Steel advocates passing a similar gas
'through a bed of sufficiently hot coke to yield molten iron, which would be
128
expected to agglomerate.
8.3.4 Steelmaking Dust and Sludge
These solids are not importantly different from blast furnace solids
unless the charge includes scrap with a significant fraction of tramp metals,
especially zinc and lead. These elements are undesirable in sinter destined
for a blast furnace. Some have in the past advocated that all such scrap be
rejected. Proper management might confine the tramp metal to a single col-
lection system and to scheduled times, permitting uncontaminated oxides to be
recycled. Commercialized systems for purging tramp metals from waste oxides
are described in a previous section.
There are alternatives. One advocates using occasional cycles of an EAF
to drive off zinc and lead from agglomerates containing waste oxides, lime-
129
stone, and coal or coke breeze. Others recommend that the waste oxides be
leached with acids such as waste pickle liquor, or with ammoniacal solutions
such as weak ammonia liquor from the coke by-product plant. Some have
argued, however, that no process short of complete reduction can adequately
decontaminate the waste oxides, because some of the zinc is bound up in stable
mixed oxides of zinc and iron.
197
-------
8.3.5 Rolling Mill Wastes
Mill scale is conventionally recycled directly to the blast furnace,
and the finer sludge from the hot rolls usually goes to the sinter plant.
When this sludge is contaminated with hydraulic or lubricating oils, the
exhaust from the sinter plant is smokey. A patent discloses that the smoke
arises near the feed end of the machine and that the smokey exhaust can be
133
routed to another portion of the bed which acts as an incinerator.
Pickling at various stages in the rolling mills was once performed with
sulfuric acid; neutralizing the waste acid usually produced an iron-bearing
calcium sulfate sludge. Modern practice has largely swung over to hydro-
chloric acid, and there are commercial regeneration processes for the spent
acid. But rinse waters still constitute a problem and neutralization of these
with lime produces a difficult suspension of iron values in a salty waste-
water. A patented option is to contact the rinse water with an immiscible
hydrocarbon solvent, such as light oil in this industry, containing a dissolved
amine.
198
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Jablin, "Environmental Assessment of Coke By-Product Recovery Plants."
U.S. Environmental Protection Agency, EPA 600/2-79-016, January 1979
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3. Directory of Iron and Steel Works of the United States and Canada. Ameri-
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1976
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199
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17. Carpenter, B. H.s et al. "Pollution Effects of Abnormal Operations in
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from Environmental Control Facilities in the Steel Industry," U.S.
Environmental Protection Agency, EPA 600/2-76-267, October 1976.
21. Katari, V. S., R. W. Gerstle, and T. Parsons, "Industrial Process Pro-
files for Environmental Use," The Iron and Steel Industry, Chap. 24.
EPA-6002-77-023X, 213 pp., February 1977.
22. Vandergrift, A. E. and L. J. Shannon. "Particulate Pollution Systems
Study," U. S. Environmental Protection Agency, APTD-0745, May 1971.
23. British Steel Corporation. "The Arising and Treatment of BSC In-Plant
Fines," Swinden Laboratory., Moorgate, Rotherham, 1975.
24. Saito, Y. "Direct Reduction Process for Recycling Steel-Plant Waste
Fines," Ironmaking Proc., 34_, 464 (1975).
25. Goksel, A. "Recovery of Iron, Zinc, and Lead from EOF Dust and Other
Steel-PIant By-Products," Ironmaking Proc., 30, 126 (1971).
26. Barnard, P. G. et al. "Recycling of Steelmaking Dusts," Proc. 34th
Mineral Waste Utilization Symposium, U.S. Dept. of Interior, Bureau
of Mines, Chicago, 1972, p. 63.
27. Brinn, D. G. "A Review of the Literature Concerning the Steel Industry
and Pollution," I Background, June 1974.
28. Wetzel, R. and Meyer, G. "Processing of Steelworks Dust and Slurry,"
Operation of Large BOF's. ISF Publication #139, 1971, pp. 44-51.
29. Dressel, W. M. et al. "Pre-reduced Pellets from Iron and Steelmaking
Wastes," AIME Preprint 73-B-82, Chicago meeting, 1973.
30. British Steel Corp., "Recycling of Steel Plant Waste Materials," Steel
Research 1974, British Steel Corporation, 1975.
31. West, N. G., "Recycling Ferrogerious Wastes," Iron Steel Int.. 49(3), 1973
32. George, H. D. and E. B. Boardman. "The IMS-Grangcold Process for
Agglomerating Steel-Mi11. Waste Material," Granges Ore News. Oct. 73,
p. 13.
33. Jablin, R. et al. "Pollution Effects of Abnormal Operations in Iron
and Steelmaking - Vol. Ill, Blast Furnace Ironmaking, Manual of Practice,"
EPA-600/2-78-118C, June 1978.
200
-------
34. Lu, W. K. (ed.), "Waste Oxide Recycling in Steel Plants," McMaster Sym-
posium on Iron and Steelmaking, McMaster University, Hamilton, Ontario,
May 1974.
35. Coy, D. W. et al. "Pollution Effects of Abnormal Operations in Iron
and Steelmaking - Vol. VI, Basic Oxygen Process, Manual of Practice,"
EPA-600-2-78-118f, June 1978.
36. Personal Communication with J. Grubbs, EPA Permits Division, November 1978.
37. Personal Communication with D. Gill, U. S. Department of Commerce,
November 1978.
38. U. S. Environmental Protection Agency. "Development Document for Effluent
Limitations Guidelines and New Source Performance Standards for Steelmaking,"
EPA-440/l-74-024-a, June 1974.
39. Evans, J. R. "Slag-Iron and Steel," Bureau of Mines Minerals Yearbook,
U.S. Department of the Interior, 1976.
40. Personal Communication with E. Young, Solid Waste Committee, American
Iron and Steel Institute, November 1978.
41. Varga, J. "Control of Steel Plant Scarfing Emissions Using Wet Electro-
static Precipitators." U.S. Environmental Protection Agency, EPA 600/
2-76-054, March 1976.
42. Conner, J. R. "Ultimate Liquid Waste Disposal Methods," Plant Engineering,
October 19, 1972.
43. Pittsburgh Office, Pennsylvania Department of Environmental Resources,
October 1978.
44. Mantell, C. L., Solid Wastes: Origin, Collection, Processing and Disposal.
John Wiley and Sons, New York, 1975.
45. Etta, C. F., Water and Wastewater Residue Management Study - Allegheny
County, Pennsylvania. The Chester Engineers, Coraopolis, Pa., 1978.
46. Personal Communication with Edward C. Levy Co., Detroit, MI, October 1978.
47. Weant, George E. and M. R. Overcash, "Environmental Assessment of Steel-
making Furnace Dust Disposal Methods," U.S. Environmental Protection Agency,
EPA 600/2-77-044, February 1977.
48. Collins, R. J. "Availability of Mining Wastes and Their Potential For
Use as Highway Material," Federal Highway Administration, FHWA-RD-76-107,
May 1976.
49. "The Prevalence of Subsurface Migration of Hazardous Chemical Sub-
stances at Selected Industrial Waste Land Disposal Sites," U.S. Environ-
mental Protection Agency, EPA 530/SW-634, October 1977.
50. "Procedures Manual for Groundwater Monitoring at Solid Waste Disposal
Facilities," U.S. Environmental Protection Agency, EPA 530/SW-611,
August 1977.
201
-------
51. "Draft Report on Pollutant Evaluation and Effects for the Solvent
Refined Coal Liquefaction Process," EPA Contract 68-02-2162, May 1978.
52. Public Law 94-580, October 21, 1976.
53. Solid Waste Disposal Facilities, Proposed Classification Criteria, EPA,
Federal Register, February 6, 1978, Part II.
54. Report of the National Technical Advisory Committee to the Secretary
of the Interior, Water Quality Criteria, Federal Water Pollution Control
Administration, Washington, D. C., April 1968.
55. International Standards for Drinking Water, 3rd Ed., WHO, Geneva, 1971.
56. Permit Application Data, Pennsylvania Department of Environmental
Resources, Pittsburgh, PA.
57. National Interim Primary Drinking Water Regulations, EPA Federal
Register, Vol. 40, No. 248-Wednesday, December 24, 1975.
58. Assessment of Industrial Hazardous Waste Practices in the Metal Smelting
and Refining Industry, Volume IV, U.S. Environmental Protection, EPA-SW
145 c.4, 1977.
59. Prices and Costs in the United States Steel Industry, The Council on
Wage and Price Stability, Washington, D.C., October 1977.
60. Personal Communication with Mike Sydlik, Greene Engineering, Pittsburgh,
PA, December 20, 1978.
61. Agarwal, J. C., H. W. Flood, R. A. Gilberti, "Preliminary Economic Analysis
of Pollution Control Systems in Metallurgical Plants," Journal of Metals.
62. Geswin, A. J., "Liners for Land Disposal Sites," U.S. Environmental Pro-
tection Agency, EPA 530/SW-137, March 1973.
63. Building Construction Cost Data 1978, 36th Edition, Robert Snow Means
Company, Inc., 1977.
64. Weiss, Samuel, Sanitary Landfill Technology, Pollution Technology Review,
No. 10, Noyes Data Corporation, Park Ridge, N.J., 1974
65. Pavoni, J. L., J. E. Heer, and D. J. Hagerty, Handbook of Solid Waste
Disposal Materials and Energy Recovery, Van Nastrand Reinhold, 1975, New York.
66. Metry, A., and F. L. Cross, "Leachate Control and Treatment," Environmental
Monograph Series, Vol. 7, Technomic, Westport, CO, 1976.
67. "Processed Blast Furnace Slag," National Slag Association, NSA 178-1.
68. "Steel Furnace Slag—An Ideal Railroad Ballast," National Slag Association,
Washington, D. C., NSA 173-3.
69. Emery, John J., "New Uses of Metallurgical Slags," Can. Min. Metal!. Bul-
letin, McMaster University, Hamilton, Ontario, Decembe'r 1975.
70. Harris, M. H. "The Use of Steel Mill Waste Solids in Iron and Steel-
making," 86th General Meeting of the American Iron and Steel Institute,
New York, May 24, 1978.
202
-------
71. Personal Communication, Mr. J. S. Young of Reclasource Corp., Chicago, IL.
January 1979.
72. Literature provided by Mr.L. L. French, President of Pelletech Corp.,
625 Stanwix St., Pittsburgh, PA 15222.
73. Brinn, D. G., "A Survey of the Published Literature Dealing with Steel
Industry In-Plant Fines and Their Recycling." British Steel Corp.,
PB-236 359, August 1974.
74. Literature Provided by Mr. W. A. Obenchain, Obenchain Corporation,
Pittsburgh, PA., January 1979.
75. Kreiger, J. W. and C. E. Jablonski, "Red Dust Turned Into Usable
Product," Pollution Engineering, 3(61), 1978.
76. West, N. 6., "Recycling Ferroginous Wastes: Practice and Trends."
Iron and Steel International, June 1976.
77. "New DR Plant at Chiba Works," Iron and Steel Engineer, April 1978.
78. Personal Communication, Mr. T. Katakabe, Manager, Technical Control,
Kawasaki Steel Corp., January 1979.
79. Personal Communication, Dr. T. Araki, Technical Service Manager,
Sumitomo Metal America, Inc., January 1979.
80. Personal Communication, Mr. T. Tanaka, Nippon Kokan K.K., January 1979.
81. "Steel Firms Eye Dust to Pellet System," Energy User News, August 8, 1977
as cited in Reference 1.
82. Rausch, H. and H. Serbent. "Beneficiation of Steel Plant Waste Oxides
by Rotary Kiln Processes." Paper presented at Sixth Mineral Waste
Utilization Symposium, Chicago, IL., May 2-3, 1978.
83. Personal Communication, Don Beggs, Midrex Corporation, Charlotte, NC,
January 1979.
84. Holowaty, M. D., "A Process for Recycling of Zinc-Bearing Steelmaking
Dusts." Paper presented at Technical Meeting of AISI, Chicago, IL,
October 1971.
85. "Steel Industry Sludge is Being Reused," Environmental Science and
Technology. 9_, July 1975.
86. Ruthner, J. J. and Othmar Ruthner, "25 Years of Process Development
in Hydrochloric Acid Pickling and Acid Regeneration," AISE Convention,
Chicago, IL, 1978.
87. EPA, Metallurgical Process Branch, "Recovery of Spent Sulfuric Acid
from Steel Pickling Operations," U.S. Environmental Protection Agency,
EPA 625/2-78-017.
88. Wadhawan, S. C., Iron and Steel Engineer, October 1978, pp. 48.
89. Ostrowski, E. J., "Recovery and Use of Ferrous Scrap from Municipal
Refuse," AFS Transactions. 85J111), 1977.
203
-------
90. "Worldwide Steel Industry Looks to Alternative for Coking Coal,"
33 Metal Producing, January 1977.
91. Miller, J. R., "Paxton Discusses All-Coal Integrated Steel Plant at
the 7th C. C. Furnas Memorial Conference," I & S Magazine, October 1977.
92. Gold, B., "Steel Technologies and Costs in- the United States and Japan,"
Iron and Steel Engineer, April 1978.
93. "Though Relatively New, Tuyere Injection Is Taking Important Role in
Iron Production," 33 Metal Producing, March 1977.
94. Keenan, G. F. and Morrson, D. M., "A Current Look at Pulverized Coal
Injection for Blast Furnaces," Iron and Steel Engineer, October 1977.
95. "Innovation and New Technology Still Mark Japanese Steel Industry,"
33 Metal Producing, February 1977.
96. Miller, J. R., "Global Status of Direct Reduction - 1977," Iron and
Steel Engineer, September 1977.
97. Williams, C. H., "Superheating for Energy and Material Conservation
in Basic Oxygen Steelmaking," Iron and Steel Engineer, June 1977.
98. Deily, R. L., "Casting Raw Steel - USA," I & S Magazine, September 1977.
99. "Model Concept Mini Steel Plant Announced for the Pittsburgh Area,"
Iron and Steel Engineer, September 1978.
100. "Worldwide Steel Industry Looks to Alternative for Coking Coal," 33.
Metal Producing, January 1977.
101. U.S. Patent Office, "Index to the U,.S. Patent Classification," Washington,
D. C., Superintendent of Documents, 1977.
102. U.S. Patent Office, "Manual of Classification," Washington, D. C., Super-
intendent of Documents, 1967.
103. Field, L. I., and B. E. Lanham, "U.S. Patent Office Classification
Definitions: Class 75, Metallurgy," Rev.l; Washington, D. C., Super-
intendent of Documents, 1967.
104. Kreiger, J. W. and C. E. Jablonski (to Bethlehem Steel), U.S. 4,003,736
of January 18, 1977; "Method for Preparing Dry-Collected Fume for Use
In Metallurgical Furnaces," Cl. 75/3.
105. Kreiger, J. W. (to Bethlehem Steel), U.S. 4,004,916 of January 25, 1977;
Method for Agglomerating Wet-Collected Fume for Use In Metallurgical
Furnaces, And Agglomerates Produced Thereby," Cl.75/3.
106. Turkdogan, E. T. (to U.S. Steel) U.S. 3,985,550 of October 12, 1976;
"Method of Producing Low-Sulfur Steel," Cl.75/60.
107. Yoshida, H. (to Aikoh Co.), U.S. 4,076,522 of February 28, 1978;'"Molten
Iron Desulfurization Method," Cl. 75/58.
108. Jablin, R. , U.S. 4,050,884, "Slag Waste On Slag Quenching Heat Boiler."
204
-------
109. Kuntz, J. B., and A. A. Spinola (to U.S. Steel), U.S. 3,785,292 of
September 11, 1973.
110. Rehmus, F. H. (to Jones and Laughlin), U.S. 3,900,304 of August 19, 1975;
"Method of Reducing H2S Emissions During Slag Quenching," Cl. 65/19.
111. Hauser, K. V. and L. A. Paulsen (to E. C. Levy Co.), U.S. 3,941,585 of
March 2, 1976; "Process for Cooling Slag and Inhibiting Pollutant
Formation," Cl. 75/24.
112. Kuntz, J. B and A. A. Spinola (to U.S. Steel), U.S. 3,761,243 of
September 25, 1973; "Method of Quenching Slag," Cl. 75/24.
113. Nagata, T. (to Nippon Steel), U.S. 3,938,975 of February 16, 1976,
"Treatment of Blast Furnace Slag." Cl. 65/19.
114. Smyers, W. H. and E. H. Manny (to Esso Research) U.S. 3,249,402 of
May 3, 1966; "Recovery of Sulfur From Blast Furnace Slag," Cl. 23/224.
(Probably reclassified at Cl. 423).
115. Osborne, F. and S. P. Kinney (to S. P. Kinney Engineers), U.S. 3,738,820
of June 12, 1973; "Method and Apparatus for the Processing of Molten
Slag," Cl. 65/19.
116. Tobias, 6. S. (to Envirotrol), U.S. 3,823,010 of July 9, 1974; "Elimina-
tion of H2S From Slag Quenching," Cl. 75/24.
117. Massey, M. J. and R. W. Dunlap (to Standard Slag), U.S. 3,897,231 of
July 29, 1975; "Method for Contacting Hot, Viscous, Molten Slag With
Gaseous Reactants," Cl. 65/19.
118. Selmeczi, J. 6. et al, (to Dravo), U.S. 3,920,795 of November 18, 1975;
"Stabilization of Sludge Slurries," Cl. 423/242.
119. Miller, A. L. (to Koppers), U.S. 4,009,024 of February 22, 1977; "Process
for Regeneration and Reuse of Steelmaking Slag," Cl. 75/30.
120. Miyashita, Y. (to Nippon Kakan), U.S. 4,102,675 of July 25, 1978; "Method
for Treating Molten Slags in Steelmaking Process," Cl. 75/30.
121. Cappell, F. (to Dravo) U.S. 4,067,727 of January 10, 1978; "Sintering
Process," Cl. 75/5.
122. Kusner, R. E., and R. W. Muthig (to Republic Steel), U.S. 4,063,930 of
December 20, 1977; "Preparation of Weatherable Ferrite Aggregates,"
Cl. 75/3.
123. Fishburn, R. A. and F. E. 6. Ravault (to Foseco), U.S. 4,015,979 of
April 5, 1977; "Bonding of Particulate Materials," Cl. 75/25.
124. Joseph, R. T. (to FMC), U.S. 3,996, 108 of December 7, 1976; "Briquetting
of Reactive Coal Calcinate With High-Temperature Coke-Oven Pitch,"
tl. 201/6.
125. Joseph, R. T. and J. Work (to FMC), U.S. 3,725,034 of April 3, 1973;
"Method of Producing Cargon- and Iron-Containing Briquettes," Cl. 75/4.
126. Maurice, H. W., and J. K. Pearce (to PECOR), U.S. 3,948,644 of April 6,
1976; "Steelmaking Vessel With Dust-Recycling Method and Means," Cl. 75/25.
205
-------
127. Hodge, A. L. and M. P. Fedock (to Republic Steel), U.S. 3,721,548 of
March 20, 1973: "Treatment of Iron-Containing Particles," Cl. 75/25.
128. Claflin, H. B. (to Kaiser Steel), U.S. 3,928,023 of December 23, 1975;
"Method of Treating Off-Gases From Iron Processes," Cl. 75/60.
129. Ban, T. E. (to McDowell-Wellman), U.S. 3,262,771 of July 26, 1966;
"Recovery of Steel and Zinc From Waste Materials," Cl. 75/11.
130. Barnard, P. G. et al, (to U.S.D.I.), U.S. 3,676,107 of July 11, 1972;
"Refining Iron-Bearing Wastes," Cl. 75/109.
131. Kupfer, R. (to Vol Roll AG), U.S. 4,018,680 of April 19, 1977; "Process
for Separating Iron, Zinc, and Lead from Flue Dust and/or Flue Sludge,"
Cl. 210/50.
132. Peters, M. A. (to Hazen Research), U.S. 4,071,357 of January 31, 1978;
"Process for Recovering Zinc from Steel-Making Flue Dust," Cl. 75/103.
133. Cappel, F. (to Metal!gesellschaft AG), U.S. 3,857,694 of December 31, 1974$
"Process for Burining Hydrocarbons and Cracked Products in Exhaust Gases
from Sintering Machines," Cl. 75/5.
134. Aue, A. I. et al, (to Gullspangs Electr. AB), U.S. 3,824,161 of July 16,
1974; "Method of Extracting Metallic Chlorides," Cl. 423/139.
135. Strassburger, J. H., General Meeting of the American Iron and Steel
Institute, New York, May 21, 1958.
136. Labee, C. J., "Sliding Bed HC1 Regeneration Process," Iron and Steel
Engineer, September 1977, p. 91.
206
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INDEX
Acid regeneration, 156
Aggolomeration processes, 148
Bast furnace 8, 40, 166
Basic oxygen process, 8, 42
Capacity, steelmaking, 13
Coke, 36, 91, 141
Continuous casting, 11, 44, 180
Direct reduction, 151, 173
Disposal, 84, 130
Dusts, 38, 81, 96, 199
Dumping, 111, 130
Economics, industry, 14
Economics, current disposal, 86, 123
Economics, RCRA, 115, 119, 132
Electric arc, 10, 44
Endangerment, 88
External desulfurization, 168
Extraction testing, 90
Finishing operations, 10, 46, 49
Flood plains, 138
Fuel injection, 167
Generation factors, 51, 53, 71
Groundwater quality, 90, 100, 133
Groundwater monitoring, 103, 116
Hazardous wastes, 32, 114, 134
Hydrogeology, 99
Iron oxides, 40, 59, 147, 195
Lagoons, 76, 122
Landfill costs, 120
Landfill sites, 120, 136
Leachate, 90, 99, 116
Leachate treatment, 114, 120
Liners, landfill, 114, 135
Miscellaneous wastes, 82, 97
Model plant, 7, 33
Model landfill, 120
Oil, 100, 106, 154
Open hearth, 33, 180
Patents, 192
Pickle liquor, 46, 83, 156, 197
Pollution, air, 71
Pollution, water, 73, 90
Pollution, groundwater, 88
Process changes, 161, 163, 181
Regional waste treatment, 64, 65
Recycle processes, 64, 141
Resource conservation, 35, 64, 140
186
RCRA, 3, 88, 113, 130
Safety, 138
Scale, 81
Scrap metal, 160, 176
Shaping, 10
Sinter, 8, 38
Slag, 42, 52, 58, 77, 94, 142, 192
Sludge, 79, 95, 195
Sulfur, 168, 194
Surface runoff, 136
Tar, coke, 6, 91, 141
Waste classification, 32, 56
Waste quantities, 55
Waste, listing of, 53, 55
207
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TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
1. REPORT NO. SW-740
EPA-600/2-79-074
3. RECIPIENT'S ACCESSION NO.
4. TITLE AND SUBTITLE
Environmental and Resource Conservation Consider-
ations of Steel Industry Solid Waste
5. REPORT DATE
April 1979
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
V.H.Baldwin, M.R.Branscome, C.C.Allen,
D. B. Marsland, B. H. Carpenter, and R. Jablin
8. PERFORMING ORGANIZATION REPORT NO.
3. PERFORMING ORGANIZATION NAME AND ADDRESS
1O. PROGRAM ELEMENT NO.
Research Triangle Institute
P.O. Box 12194
Research Triangle Park, North Carolina 27709
2DB662, 1AB604, and 1BB610
11. CONTRACT/GRANT NO.
68-02-2612, Task 73
12. SPONSORING AGENCY NAME AND ADDRESS
EPA, Offices of Research and Development
and Solid Waste
Washington, DC 20460
13. TYPE OF REPORT AND PERIOD CC
Task Final; 5/78 - 2/79
COVERED
14. SPONSORING AGENCY CODE
EPA/600/13
15. SUPPLEMENTARY NOTES EPA project off leers: John Ruppersberger (IERL-RTP, 919/541-
2733); William J. Kline (Office of Solid Waste, 202/755-9120).
ABSTRACT
repOrt examines the solid wastes generated by the iron and steel indus-
try relative to the impact of Section 4004 of the Resource Conservation and Recovery
Act. The quantities , properties , and origin of wastes which pose a potential problem
are identified using flow diagrams , material balances , and generation factors . Of
the estimated 140 million metric tons of solid waste (including inplant mill scrap)
generated annually, 80% is either recycled or reused. Waste disposal practices are
discussed, and the potential for groundwater pollution has been identified. The capi-
tal cost to collect leachate from nonhazardous wastes which could potentially endan-
ger the groundwater was estimated to increase the current landfill costs by 40%;
however , this cost was less than 1% of the estimated future overall environmental
cost.
17.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b. IDENTIFIERS/OPEN ENDED TERMS
c. COS AT I Field/Group
Pollution Leaching
Iron and Steel Industry
Resources Earth Fills
Conservation Circulation
Waste Disposal
Water Pollution
Pollution Control
Stationary Sources
Solid Waste
13B
11F,05C
15E
14G
13C
13. DISTRIBUTION STATEMENT
Unlimited
19. SECURITY CLASS (This Report/
Unclassified
21. NO. OF PAGES
224
20. SECURITY CLASS (Thispage)
Unclassified
22. PRICE
EPA Form 2220-1 (9-73)
208
-------
"Environmental and Resource EPA-600/2-79-074
Conservation Consideration of SU-740
Steel Industry Solid Waste" September 1979
ERRATA SHEET
Page Correction
Change Table 41 title to: "Permissible Criteria for Selected
Components for Public Water Supplies."
9 Change last sentence of 2nd paragraph to: "This blast furnace
slag is currently used primarily as road bed and construction fill."
10 Below Figure 2 title add: "(General College Chemistry, 3rd
Edition, p. 542, by J.A. Babor and A. Lehrman. (T.Y. Crowell)
Copyright 1929, 1940, 1951 by Harper & Row, Publishers, Inc.
Reprinted by permission.)"
20 To Figure 7 title add: '©Rand McNally & Company, R.L. 79-Y-77."
33 In next to last sentence of 1st paragraph insert "in" between
"waste" and "relation."
34 Change last sentence of 3rd paragraph to: "...industry will be
only slightly increased by compliance with anticipated air and
water regulations."
91 Substitute revised Table 41, attached.
95 In 2nd sentence of third paragraph change "In each" to "For each."
Then add "This causes concern for the potential for groundwater
endangerment . "
Change last sentence of 4th paragraph to: "...in Table 46 may
require the use of a lined landfill wherever the leachate may
endanger the groundwater."
114 Between the two sentences .of the 3rd paragraph add: "This causes
concern for the effect of leachate on the groundwater." Change
the next sentence to "...have been identified in the extract of
some of the various iron and steel wastes at concentrations
greater than the permissible critieria."
In the 2nd sentence of the 4th paragraph, change "would" to
"could."
131 In Table 63 footnote change "Excluded" to "Included."
132 In Table 65 title change "Excluded" to "Included."
152 Below Figure 24 title add: "(M.M. Harris, "The Use of Steel Mill
Waste Solids in Iron and Steelmaking." Copyrighted by American
Iron and Steel Institute, 1978. Reprinted by permission.)"
164 Below Figure 25 title add: "(Iron and Steel Maker, October 1977)."
Page 1 of 2
-------
"Environmental and Resource EPA-600/2-79-074
Conservation Consideration of SW-740
Steel Industry Solid Waste" September 1979
ERRATA SHEET
Page Correction
171-173 Below Figure 26,27, and 28 titles add: "(Proceedings: Symposium
on External Desulfurization of Hot Metal. Reprinted by permission
McMaster University.)"
178 Below Table 75 add: "(Iron and Steel Engineer, September 1977)."
207 Substitute revised Index, attached.
208 Substitute revised Technical Report Data form, attached.
Page
2 of 2
-------
TABLE 41. PERMISSIBLE CRITERIA FOR SELECTED COMPONENTS
FOR PUBLIC MATER SUPPLIES.
Constituent Permissible Criteria (mg/fc)
pH 6.0-8.5b
Arsenic 0.05a'b
Barium 1.0a'b
Cadmium 0.010a'b
Chromium 0.05a'b
Fluoride 1.2 (63.9-70.6°F)b
Iron (filterable) 0.3b
Lead 0.05a'b
Manganese (filterable) 0.05
Selenium 0.01a»b
Silver 0.05a'b
Total dissolved solids 500.Ob
Zinc 5.0b
Carbon chloroform extract 0.15
Cyanide 0.2b
Oil and grease Virtually absent
Phenols 0.001b
Mercury 0.002a
aNational Interim Primary Drinking Water Regulations
bWater Quality Criteria, Department of Interior, FWCPA54
7.3.2 Water Extraction of Solid Waste Materials
Water extraction tests were reported by six plants to PDER (Code A, B,
E, F, 6, and H) as well as from an EPA survey58 (C) and ASTM15 (D). These tests
differ from the proposed EPA Extraction Procedure in that distilled water was
used, whereas the proposed EPA procedure uses a limited amount of acetic acid
for pH control. Higher levels of heavy metals are expected from these tests
when acetic acid is used. The ASTM leachate values were reported by Enviro
Control15 with additional ASTM testing provided by AISI. Although ASTM
tested the wastes with several different types of water, only the 48 hour
91
-------
INDEX
Acid regeneration, 157
Aggolomeration processes, 148
Bast furnace 9, 39, 167
Basic oxygen process, 10, 43
Capacity, steel making, 14
Coke, 37, 92, 141
Continuous casting, 12, 45, 181
Direct reduction, 151, 174
Disposal, 85, 133
Dusts, 39, 82, 97, 197
Dumping, 111, 133
Economics, industry, 15
Economics, current disposal, 87, 124
Economics, RCRA, 114, 120, 132
Electric arc, 11, 45
Endangerment, 89
External,desdulfurization, 169
Extraction testing, 91
Finishing operations, 50
Flood plains, 138
Fuel injection, 168
Generation factors, 52, 54, 73
Groundwater quality, 90, 101, 133
Groundwater monitoring, 101, 116
Hazardous wastes, 33, 114, 135
Hydrogeology, 100
Iron oxides, 60, 147, 196
Lagoons, 77, 123
Landfill costs, 120
Landfill sites, 120, 137
Leachate, 90, 100, 117
Leachate treatment, 114, 122
Liners, landfill, 114, 136
Miscellaneous wastes, 83, 98
Model plant, 8, 34
Model landfill, 120
Oil, 95, 101, 155
Open hearth, 34, 181
Patents, 192
Pickle liquor, 47, 84, 156, 198
Pollution, air, 72
Pollution, water, 74, 90
Pollution, groundwater, 90
Process changes, 162, 182
Regional waste treatment, 65, 66
Recycle processes, 65, 140
Resource conservation, 36, 65, 140
185
RCRA, 2, 33, 89, 114, 133
Safety, 139
Scale, 83
Scrap metal, 161, 179
Shaping, 11
Sinter, 9, 40
Slag, 41, 43, 53, 59, 78, 94, 142
195
Sludge, 80, 95, 96, 196
Sulfur, 169, 195
Surface runoff, 137
Tar, coke, 6, 92, 141
Waste classification, 33, '57
Waste quantities, 56
Waste, listing of, 54, 56
207
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TECHNICAL REPORT DATA
(Fteose nad Imamctions on the revene before completing)
1. REPORT NO. SW-740
EPA-600/2-79-074
2.
. RECIPIENT'S ACCESSION NO.
4. TITLE AND SUBTITLE
Environmental and Resource Conservation Consider-
ations of Steel Industry Solid Waste
i. REPORT DATE
April 1979
ft. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
V.H.Baldwin, M.R. Brans come, C.C.Allen,
D. B. Mars land, B. H. Carpenter, and R. Jablin
PERFORMING ORGANIZATION REPORT NO.
J PERFORMING ORGANIZATION NAME AND ADDRESS
Research Triangle Institute
P.O. Box 12194
Research Triangle Park, North Carolina 27709
10. PROGRAM ELEMENT NO.
2DB662, 1AB604, and 1BB610
11. CONTRACT/GRANT NO.
68-02-2612, Task 73
12. SPONSORING AGENCY NAME AND ADDRESS - COSpOTlSered D/
EPA, OSW (WH-565)
401 M Street SW
Washington, DC 20460
EPA, ORD
IERL (MD-62)
&TP, NC 27711
13. TYPE OF REPORT AND PERIOD COVERED
Task Final; 5/78 - 2/79
14. SPONSORING AGENCY CODE
EPA/600/13
15. SUPPLEMENTARY NOTES EPA prOJCCt
John Ruppersberger t IERL-RTP(MD-62),919/541-2733
Bill Kline . Office of Solid Waste (WH-565). 202/755-9202
:
i« ABSTRACT Ti)e report examines the solid wastes generated by the iron and steel indus
try relative to the impact of Section 4004 of the Resource Conservation and Recovery
Act. The quantities, properties, and origin of wastes which pose a potential problem
are identified using flow diagrams, material balances, and generation factors. Of
the estimated 140 million metric tons of solid waste (including inplant mill scrap)
generated annually, 80% is either recycled or reused. Waste disposal practices are
discussed, and the potential for groundwater pollution has been identified. The capi-
tal cost to collect leachate from nonhazardous wastes which could potentially endan-
ger the groundwater was estimated to increase the current landfill costs by 40%;
however, this cost was less than 1% of the estimated future overall environmental
cost.
17.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.lDENTIFIERS/OPEN ENDED TERMS
E. COSATI Field/Group
Pollution Leaching
Iron and Steel Industry
Resources Earth Fills
Conservation Circulation
Waste Disposal
Water Pollution
Pollution Control
Stationary Sources
Solid Waste
13B 07D,07/
11F,05C
15E 13C
14G
18. DISTRIBUTION STATEMENT
Unlimited
19. SECURITY CLASS (ThisRtport)
Unclassified
21. NO. OF PAGES
224
20. SECURITY CLASS (This pagtj
Unclassified
22. PRICE
EPA Form 2220-1 (»-7»)
208
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