EPA-650/2-74-115
OCTOBER 1974
Environmental Protection Technology Series
illl
£
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SB.
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EPA-650/2-74-115
TRACE POLLUTANT EMISSIONS
FROM THE PROCESSING
OF METALLIC ORES
by
V. Katari, G. Isaacs, and T. W. Devitt
PEDCo-Environmental Specialists, Inc.
Atkinson Square (Suite 13)
Cincinnati, Ohio 45246
Contract No. 68-02-1321
Task 5
ROAP No. 21AUZ-02a
Program Element No. 1AB015
EPA Project Officer: D . K. Oestreich
Control Systems Laboratory
National Environmental Research Center
Research Triangle Park, North Carolina 27711
Prepared for
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON, D. C. 20460
October 1974
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This report has been reviewed by the Environmental Protection Agency
and approved for publication. Approval does not signify that the
contents necessarily reflect the views and policies of the Agency,
nor does mention of trade names or commercial products constitute
endorsement or recommendation for use.
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ACKNOWLEDGMENT
This report was prepared for the U.S. Environmental
Protection Agency by PEDCo-Environmental Specialists, Inc.,
Cincinnati, Ohio. Mr. Timothy W. Devitt was the PEDCo
Project Manager. Principal authors of the report were Mr.
Vishnu Katari, Mr. Gerald Isaacs and Mr. Devitt
Mrs. Anne Cassel was the project editor. Mr. Chuck
Fleming was responsible for report graphics and final report
preparation.
Mr. D. Oestreich was the Project Officer for the U.S.
Environmental Protection Agency. PEDCo appreciates the
assistance and cooperation extended by the Project Officer,
various members of the Control Systems Laboratory, and Mr.
Paul W. Spaite, EPA consultant.
111
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TABLE OF CONTENTS
Page
ACKNOWLEDGMENT
LIST OP FIGURES ix
LIST OF TABLES xi
1,0 INTRODUCTION 1-1
2.0 IRON AND STEEL INDUSTRY 2-1
2.1 Industry Background 2-1
2.2 Raw Materials 2-3
2.3 Products 2-8
2.4 Process Description 2-9
2.4.1 Mining Operations 2-9
2.4,2 Beneficiation 2-10
2.4.3 Agglomeration 2-15
2.4.4 Pig Iron Production 2-20
2.4.5 Steel Manufacture 2-26
2.4.6 Casting and Finishing Operations 2-34
2.4.7 Coking 2-35
2.4.8 Direct Metal Reduction Processes 2-38
2.5 Major Pollutant Sources 2-40
3.0 FERROALLOY INDUSTRY SEGMENT 3-1
3.1 Industry Background 3-1
3.2 Raw Materials 3-2
3.3 Products 3-3
3.4 Process Description 3-3
3.4.1 Ore Handling and Beneficiation 3-3
3.4.2 Smelting 3_4
3.4.3 Slag Processing 3-11
3.4.4 Finishing Operations 3-12
3.5 Major Pollutant Sources 3-13
4.0 COPPER INDUSTRY 4-1
4.1 Industry Background 4-1
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TABLE OF CONTENTS
Page
7.0 ALUMINUM INDUSTRY 7-1
7.1 Industry Background 7-1
7.2 Raw Materials 7-3
7.3 Products 7-7
7.4 Process Description 7-8
7.4.1 Bayer Process 7-8
7.4.2 Combined Process 7-13
7.4.3 Production of Aluminum 7-14
7.4;4 Finishing Operations 7-20
7.5 Major Pollutant Sources 7-22
8.0 TITANIUM INDUSTRY 8-1
8.1 Industry Background 8-1
8.2 Raw Materials 8_9
8.3 Products 8-11
8.4 Process Description 8-12
8.4.1 Mining 8-12
8.4.2 Beneficiation 8-14
8.4.3 Smelting 8-17
8.4.4 Metal Production 8-17
8.4.5 Pigment Production 8-21
8.5 Major Pollutant Sources 8-22
9.0 URANIUM INDUSTRY 9-1
9.1 Industry Background 9-1
9.2 Raw Materials 9-7
9.3 Products 9-9
9.4 Process Description 9-10
9.4.1 Mining 9-10
9.4.2 Milling 9_14
9.4.3 Extraction Process 9-17
vii
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TABLE OF CONTENTS
Page
9.4.4 Refining Operation 9-18
9.4.5 Enrichment 9-20
9.4.6 Fuel Pellet Manufacturing 9-21
9.4.7 Fuel Element Manufacturing 9-22
9.4.8 Nuclear Power Generation 9-22
9.4.9 Fuel Reprocessing 9-23
9.5 Major Pollutant Sources 9-24
10.0 RECOMMENDATIONS 10-1
APPENDIX A METAL PRODUCTION AND CONSUMPTION A-l
STATISTICS (1971)
APPENDIX B IRON ORE MINING AND PRODUCTION B-l
STATISTICS
APPENDIX C PRODUCTION STATISTICS OF FERROALLOYS C-l
APPENDIX D COPPER MINE PRODUCTION STATISTICS D-l
APPENDIX E LEAD PRODUCING MINES IN THE UNITED E-l
STATES
APPENDIX F ZINC PRODUCTION IN THE UNITED STATES, F-l
BY STATE, 1971
APPENDIX G ALUMINUM, ALUMINA AND BAUXITE PRODUCTION G-l
STATISTICS
APPENDIX H TITANIUM CONSUMPTION (UNITED STATES) H-l
STATISTICS
APPENDIX I URANIUM MINING AND PROCESSING COMPANIES 1-1
Vlll
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LIST OF FIGURES
Figure Page
2.1 Iron and Steel Production 2-11
2.2 Coke Plant Operation 2-36
3.1 Ferroalloy Production 3~5
4.1 Copper Industry 4~5
5.1 Primary Lead Production 5~7
6.1 Primary Zinc Production 6~7
7.1 Primary Aluminum Industry 7~9
8.1 Titanium Process Flow Sheet 8~13
9.1 Uranium Industry 9-11
A-l Antimony Production and Consumption A-2
Statistics (1971)
A-2 Bauxite (aluminum ore) Production and A-3
Consumption Statistics (1971)
A-3 Bismuth Production and Consumption A-4
Statistics (1971)
A-4 Cadmium Production and Consumption A-5
Statistics (1971)
A--5 Chromite Production and Consumption A-6
Statistics (1971)
A-6 Cobalt Production and Consumption A-7
Statistics (1971)
A~7 Columbium and Tantalum Statistics (1970) A-8
A-8 Copper Production and Consumption A-9
Statistics (1971)
IX
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LIST OF FIGURES
Figure Page
A-9 Iron Production and Consumption A-10
Statistics (1970)
A-10 Lead Production and Consumption A-11
Statistics (1971)
A-ll Magnesium Production and Consumption A-12
Statistics (1971)
A-12 Manganese Production and Consumption A-13
(1971)
A-13 Mercury Production and Consumption A-14
Statistics (1971).
A-14 Molybdenum Production and Consumption A-15
Statistics (1971)
A-15 Nickel Production and Consumption A-16
Statistics (1971)
A-16 Tin Production and Consumption A-17
Statistics (1971)
A-17 Titanium Production and Consumption A-18
Statistics (1971)
A-18 Tungsten Production and Consumption A-19
Statistics (1971)
A-19 Uranium Production and Consumption A-20
Statistics (1971)
A-20 Vanadium Production and Consumption A-21
Statistics (1971)
A-21 Zinc Production and Consumption A-22
Statistics (1971)
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LIST OF TABLES
Table Page
1.1 Quantities of Ore Mined and Processed in the 1-2
United States
1.2 Relative Toxicities of Potential Air 1-6
Pollutants
2.1 Iron Ore Mined in the United States 2-4
2.2 Iron-Bearing Minerals 2-5
2.3 Analysis of Taconite Ores 2-6
2.4 Iron Ore Analyses 2-7
2.5 Typical Taconite Concentrate Analysis 2-13
2.6 Average Grade of Sinter .and Pellets Produced 2-16
in 1968 Northeastern Iron Ores
2.7 Particle Size Analysis of Particulate Emis- 2-17
sions from a Sintering Machine
2.8 Compositions of Pellets Produced from Con- 2-18
centrates Originating with Magnetite
Taconites (1968)
2.9 Typical Operating Statistics 2-19
2.10 Chemical Analysis of Nodulized Product, 2-20
Average
2.11 Blast Furnace: Input and Output Materials 2-22
2.12 Analysis of Limestone from Columbus, Ohio 2-22
2.13 Chemical Analyses of Dry, Blast Furnace 2-23
Flue Dust
2.14 Size Analysis of Flue Dust from U.S. Blast 2-23
Furnaces
XI
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LIST OF TABLES
Table page
2.15 Slag Analysis 2-24
2.16 Analysis of Furnace Gas 2-25
2.17 Chemical Compositions of Electric-Furnace 2-28
Dusts
2.18 Changes in Composition of Electric-Furnace 2-28
Dust During a Single Heat
2.19 Chemical Compositions of Open-Hearth ^-30
Particulate Emissions, Oxygen Lancing
2.20 Operating Data for Basic Oxygen Furnace 2-31
2.21 Chemical Composition of Basic Oxygen Furnace 2-32
Steelmaking Dust from Three Typical U.S. Plants
2.22 Dust and Metal Analyses for Vacuum-Treated 2-32
Steels
2.23 Calculated Gas Composition for 100-Ton EOF 2-33
Blown at 12,000 SCFM O2 Rate for 20 Minutes
2.24 Emission Factors for By-Product Coke 2-39
Manufacture Without Controls
3.1 Exhaust Flow from Electric Furnaces Process- 3-7
ing Common Ferroalloys
3.2 Particulate Emissions from Ferroalloy 3-7
Production
3.3 Typical Characterizations of Ferroalloy 3-8
Furnace Fumes
4.1 Major Copper-Bearing Ores 4-3
4.2 Typical Analysis of Copper Ore Used at White 4-5
Pine Copper Company, Michigan
4.3 Coproduct and By-Product Relationships of 4_g
Copper with Other Metals
4.4 Analysis of Copper Concentrate 4-11
4.5 Comparative Analyses of Tailings, Undisturbed 4-12
Desert, and Overburden Areas, Pima Mining
Co., 1972
4.6 Typical Input and Output to a Copper Roaster 4-15
4.7 Distribution of Elements in Feed to a 4-15
Copper Roaster
xii
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LIST OF TABLES
Table Page
4.8 Contaminants of Gas Stream from Roaster 4-16
4.9 Distribution of Elements in Reverberatory 4-17
Furnace Feed
4.10 Composition of Reverberatory Furnace Exhaust 4-18
Gases
4.11 Distribution of Elements in Charge to the 4-19
Converter
4.12 Disposition of Elements in Feed to Refining 4-21
Furnace
4.13 General Range Analysis of Anode, Electrolyte, 4-22
Refined Copper, and Anode Slime
5.1 Lead Minerals, By Name, Composition 5-2
5.2 Coproduct and By-product Relationships of 5-5
Lead and Other Metals
5.3 Typical Analysis of a Lead Concentrate 5-8
5.4 Typical Analysis of Pressure Leach Feed, 5-10
Residue, and Leach Solution
5.5 Analysis of Sinter Machine Gases (Missouri 5-12
Lead Operating Company)
5.6 Typical Sintering Machine Feed and Products 5-13
5.7 Typical Blast-Furnace Charge 5-14
5.8 Typical Blast-Furnace Materials and Products 5-15
6.1 Zinc Smelter and Electrolytic Refinery 6-3
Capacities
6.2 Zinc-Bearing Minerals 6-4
6.3 Zinc By-product and Coproduct Relationships 6-5
6.4 Elements That May Be Found in Zinc Con- 6-9
centrates
6.5 Disposition of Elements in the Feed to 6-10
Roaster
6.6 Typical Zinc Sintering Operations 6-13
xna
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LIST OF TABLES
Table Page
6.7 Disposition of Elements in Charge to 6-15
Horizontal Zinc Retort
6.8 Disposition of Elements in Charge to 6-18
Electrolytic Zinc Plant
6.9 Operating Data of Rotary Furnaces for 6-20
Obtaining Zinc Oxide
7.1 Distribution of Plants by Population 7-2
7.2 Chemical Composition of Bauxites 7-5
7.3 Chemical Composition of Bauxite in Georgia 7-5
7.4 Composition of Imported Bauxite 7-6
7.5 Raw Materials for Production of Aluminum 7-7
7.6 Typical Composition of Alumina 7-7
7.7 Insoluble Solids of Red Mud from Jamaican 7-11
Bauxite
7.8 Slurry Soluble Solids of Red Mud from 7-11
Jamaican Bauxite
7.9 Chemical Analyses of Red Muds 7-12
7.10 Composition of a High Quality Alumina 7-13
7.11. Anode Baking Ring Furnace Emissions 7-15
7.12 Operating Requirements of Prebaked Anode 7-17
and Soderberg Systems
7.13 Representative Particle Size Distributions 7-19
of Uncontrolled Effluents from Prebaked and
Horizontal-Stud Soderberg Cells
",14 Estimated Composition of the Air Discharged 7-20
from the Cell Room Before Control Equipment
7.15 Aluminum Smelter Effluents Models 7-21
8 . 1 Sources and Estimates of Titanium-Containing 8-24
Emissions
9.1 U.S. Uranium Milling Companies and Plants in 9-3
1971
xiv
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LIST OF TABLES
Table Pa9e
B-l Economic Facts of Life Place On-Going Emphasis B-2
on Pellets as U.S. Natural Ore Operations
Continue Phase-O
C-l Ferroalloys Produced and Shipped from Furnaces C-2
in the United States (1971)
C-2 Producers of Ferroalloys in the United States C-3
in 1971
D-l United States Principal Copper Mine Statis- D-2
tics/Capacities and/or 1972 Production
E-l Lead Producing Mines in United States E-2
E-2 Mine Production of Recoverable Lead in the E-4
United States, By State
F-l Production of Lead and Zinc in the United F-2
States in 1971, By State and Class of Ore,
From Old Tailings, etc., in Terms of Re-
coverable Metals
G-l Matrix of the Characteristics of Primary G-2
Aluminum Plants
G-2 Capacities of Domestic Alumina Plants, G-3
December 31, 1971
G-3 Mine Production of Bauxite and Shipments G-4
From Mines and Processing Plants to Consumers
in the United States
H-l Consumption of Titanium Concentrates in the H-2
United States, By Product
1-1 U.S. Uranium Milling Companies and Plants in 1-2
1971
1-2 Principal Companies with Capacity for Process- 1-3
ing and Fabricating Nuclear Fuel Materials in
1971
xv
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1.0 INTRODUCTION
The objective of this study was to identify potentially
significant sources of hazardous emissions in the metallic
ore mining and processing industries. For analysis of the
industrial activities associated with mining and processing
of metallic ores, the following data were collected.
1) Quantities of domestic production, imports, exports,
and consumption of each ore.
2) Composition of selected ores.
3) Quantity and composition (whenever possible) of air,
water and solid waste discharges.
Table 1.1 presents 1971 data on the quantities of 21
ores mined and processed in the United States. Additional
information on the amount of domestic production, imports,
exports, and consumption patterns for each of these ores is
presented in Figures A-l through A-21 in Appendix A.
On the basis of quantity of ore produced, tpxicity of
potential emissions, potential for fugitive dust emission,
and process operations, the following industries were
selected for detailed study.
0 Iron and Steel Industry
0 Ferroalloy Industry
o
o
o
Primary Copper Industry
Primary Lead Industry
Primary Zinc Industry
0 Aluminum Industry
* Titanium Industry
0 Uranium Industry
1-1
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Table 1.1 QUANTITIES OF ORE MINED AND PROCESSED
IN THE UNITED STATES1
Type of ore
Antimony
Bauxite
Bismuth
Cadmium
Chromite
Cobalt
Columbium
Copper
Iron
Lead
Magnesium
Manganese
Mercury
Molybdenum
Nickel
Tin
Titanium
Tungsten
Uranium
Vanadium
Zinc
Amount of ore
mined in U.S.
(tons)
1,025
2,300,000
800
4,000
0
W
W
242,500,000
240.,-OOQ,000
60,400,000
N/A
200,000
670
55,000
13,000
W
710,000e
34,500e
6,000,000
5,200
534,000b
Amount of ore
processed in U.S.a
(tons)
14,000b
16,000,000
1,200
5,600
1,000,000
5,600C
2,860C
243,000,000
295,000,000d
60,400,000
127,156
2,100,000
2,000
55,000
130,000
46,940
i,ioo,oooe
34,500e
120,000e
4,400
l,100,.000b
a) Includes, domestic processing of imported ores, where
applicable.
b) Metal content of, ore. Quantity- of ore processed could
range from 20 to 100 times the metal content value.
c) Imported ore
e)
W)
Includes secondary metals processing.
Ore concentrates.
Data withheld by U.S. Bureau of Mines to avoid dis-
closure of production capacity of individual companies
Not available.
1-2
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Process flow sheets for these selected industries were
prepared identifying major processes and material flow.
Sources of emissions of various pollutants are identified.
Descriptions of processes entailed in the individual in-
dustries are presented in Chapters 2 through 9.
These chapters are further divided into five sections.
The first section presents background information on the
industry. The second section describes raw materials in-
cluding area of availability and different ore types. The
third section lists the products and by-products of the
industry. The fourth section describes the process, process
operating conditions, process emissions, and material
handling procedures. The fifth section identifies the most
significant emission sources within the industry.
In conducting this study a common set of nomenclature
developed by EPA's Control Systems Laboratory was used so
that the output of this study would parallel that of other
CSL contractors studying other industries. The terms used
and their definitions are listed below.
1. RAW MATERIALS are feed materials for processes. They
are of two types: primary raw materials that are used
in the chemical form that they were taken from the
land, water or air and secondary raw materials that are
industrial intermediate products.
2. INDUSTRIES are made up of groups of companies that are
considered competitors in production of the same pro-
ducts. Industries have an identifiable population of
companies and have a high degree of commonality with
respect to raw materials consumed, processes employed,
products produced, environmental control problems
experienced, pollutants produced and control equipment
used.
1-3
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3. OPERATIONS are- general industrial procedures by which
materials are processed or products produced. Oper-
ations can consist of a series of processes, or can be
accomplished by two or more alternative processes.
4. PROCESSES are the basic units that collectively de-
scribe industries. Processes comprise specific ar-
rangements of equipment that accomplish, in a distinct
way, chemical or physical transformation of input
materials into end products, intermediate products,
secondary raw materials or waste materials. Other
process outputs include waste streams to the air,
water,-or land. Input materials can include primary or
secondary raw materials, waste materials, or inter-
mediate products. Where two or more different com-
binations of process steps accomplish the same chemical
or physical transformation but have different environ-
mental impacts (e.g., different emission character-
istics), each combination is a distinct process.
5. PROCESS STEPS are the basic components of a process
that utilize process equipment or materials handling
equipment (process equipment.does- not include control
equipment). In cases where a piece of process equip-
ment has two or more cycles or phases of operation with
distinctly different emissions to the atmosphere, such
cycles or phases can be considered sequential process
steps.
6. SOURCES are process steps from which significant
amounts of air, water, or land pollution can be dis-
charged.
7. CONTROL EQUIPMENT is equipment whose primary function
is to reduce emissions to the atmosphere. Its presence
is not essential to the economic viability of the
process.
8. COMPANIES include corporate sub-divisions that have a
product slate similar to other companies in an in-
dustry.
9. PLANTS are comprised of collections of processes to
produce the products associated with their industry.
Individual plants within an industry may employ dif-
ferent combinations of processes but all plants will
have some of the processes that are common to the
industry.
10. END PRODUCTS include only those process outputs that
are marketed for use or consumption in the form that
they exit from the process. After use, an end product
becomes a waste material.
1-4
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11. INTERMEDIATE PRODUCTS are process output streams that
go either to other processes in the same industry in
which they are produced, or to other industries where
they become secondary raw materials.
12. WASTE MATERIALS are either process outputs that go to a
scavenging industry, or are used end products that are
disposed or processed to recover reusable constituents.
The relative toxicity of various pollutants is pre-
sented in Table 1.2.
Chapter 10 identifies the most significant sources of
emission discussed in the preceding chapters. Appendices B
through I present relevant industry statistics.
1-5
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Table 1.2 RELATIVE TOXICITIES OF POTENTIAL AIR POLLUTANTS'
(Selected TLV's for Toxic Dusts, Fumes and Mists-)
Substance
ftcrylliuffl
Pletinum, wolublff »aH •
5ilver; me? si and solubi* ',. 'f
compound*. ......
Mercury, vapor, inorg. and org.
C'>wpourvt3 'except "*l*ylf Hg-^ 0 = 01 J
j*i-^ >.yX i •snovft-* t*»
I*). :"'l£ 7-OXJ.C , -
:*»r.1,. t*tr**t^-*
C^^iuff cxida £un«
Cfreintc aci* and c ' • r -jma t».- s
C.;:;.'*l t ~v " ;.. , *'•:.' v; : .; a-iat.
V*::•• '-•> " * ' ' ' '
!>.J,( ' -V Vr*f ^
L#*<5 " '-•,;•"'•
x ' :-:. - r> f *.'. -•.»-.*. civ^
*.' "•;--, .^ .s •+ . _r
' ' * ~
lt>' - - • \ . ' V. ; »-..-.•..,' --.i .!•(,<*
*. - . f.f.
--••>,•'.•' . -',-'• "• -' •*
£•-. . - -
-.- •- -•- - • .:. -.r-un-i
-.. -..-?• :. "-~ ••_•-*.-
• ••:-;* t- ..
- * 1^"* *
t-,' • • '
': .*" • •- T' ., -^ -. 'J3t*
;• *• ••• .» .-'»'.- ri ;: s
."• • . :- : .»;.«; ap.i ir-.colobl*
•* - t y
,- !.;»'-» f.iio raU-t»
. . :;aw;
. .rjx-.Ja
.. , :.« ».- .-.»
. •. ".' f r ' . varxad.lv.y5i dv-*;t;
•:,'3",a~~ .• .:• .,:."•' ; '.f >:-o3pounda
'.,"'. • ': .'.'--'^ ;. '• :, * ^'"' '
^"L
-•'•- - ?..-)il.~i> -.--r'.jv.-, .rid
- •::-. .. ^ . * .. -.•.-ft.
"" ' ~'l'
TLV..(»j£ s':*!
'9.9!^
O.SOJ
0.01 . • .
o.os'
'.*..:
s. ••-.
f ,
C.I (e» i"b.'
o.i ;»s cdj
S.I (as CrO. )
.5 '
"5 71?
:: , '.• v 'c.» : ,• '
;,... • • . • ••
' *,
•
C,; ., ;'-' •
f
•" 2 :*.* S« i
0 ? '*.=- '."
C, * ;'#* ;;t •
C.* {«« s»)
• si
0,5 (»e Or?
O.i
c **
•i-7
1
1
I
1
1
1
1 <*T fe)
1
1
1
}
1 >** W)
1
t-pFcf-
i.trppc f -
Jr., !«,-{-
yub.atance
ToxiQ
Asphalt (pctroleura^ funvs '
Hydrogen fluoride (KFi
Sod.i -a .lyiroxtde
Tin conpounds (except organic
cofflpounda, 0.1: SnO», 15 and SnH
PiuoriSe aalta
i^i.Vorln« (Ci-5
Cacboft ^lac>;
' iical £uFt '^ i twsi->-H9 '•
Calcium oxide
Ci'anidea ; . ?
.•ibrct- glare i'3- -*•--;
•Pen.:* Her. yds. :
-Kar.giM»e ' ' '
>-v iy^/0.ei>ura, «c-Juii« v • ^..w^s
•Ki?7iv ac^c •.- .
;V. -lijt/par-tiejli,.-
Tungsten, iomolubl* cj^;;ov*n^a
Zinc'oxitH, fu '
w^drc.j-?' C^-C•.::.•1S
«ntro«n dioxida
hydrogen broflsid*
Iron oxide fuffi*
>tathyl nercaptui
^sr^cxi <:V»t, total duatL
Sulfur dioxida
Hy-Jrogen «.lfid«
Anorp.hoas silica (incl . diatoisa-
c«ou> earth)
Mica, toapatcne, and talc
K^id or Low Toxicity
Boron oxide
Magnesium oxide fume
Molybdenum, ineolubl* compound!
Axaonia
Carbon aonoxida
Carbon tetraohloride
Benzene
Methyl alcohol
Perchioroathylene
Liquefied petroleum gaa
"Inert" or Nuisance Particulates
!rc»pt
cas'.or, cashew nut cr sirilar
irritant oils;
TLV («J »"J)
1
1
' ' 1
J
4*
J.J (4* t)
}
-- *
».i sre*»>ir«AS*
S
5 Ca» CK)
J
«
*
i
>;
I :/,* «)
: »••-'"
iO
iO
IS
111
U
IS
20mppcf-
JOappcf-
15
IS
IS
35
55
«5
*0
2«0
«70
1800
15 (or SOmppcf-)
-------
REFERENCES FOR CHAPTER 1
1. U.S. Bureau of Mines, Minerals Year Book, 1970.
2. Vandegrift, A.E. et.al. Particulate Pollutant Systems
Study, Final Report. Prepared for the U.S. Environ-
mental Protection Agency, Division of Process Control
Engineering, Research Triangle Park, North Carolina.
Contract No. CPA 22-69-104.
1-7
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2.0 IRON AND STEEL INDUSTRY
2.1 INDUSTRY BACKGROUND3*l
The United States is a major consumer of iron. It produces
an estimated 13 percent and consumes approximately 25 percent
of the world's supply. Transportation and construction industries
are the major U.S. consumers, each accounting for approximately
25 percent of the total domestic consumption. It is estimated
that an additional 20 percent is consumed in the manufacture of
industrial and agricultural machinery and equipment. The remain-
ing consumption includes use in a variety of products, such as
oil and gas equipment and home appliances.
Domestic demand for primary iron in the year 2000 is pro-
jected to be 130 to 175 million short tons.* By comparison,
the 1971 consumption of primary iron was 84 million tons, of
which about 92 percent was processed into carbon and alloy steels.
Continued upward trends in transportation, particularly in
the automobile industry to parallel the national economy, com-
bined with mass production of steel-based modular housing and
other construction, are major factors that could result in
reaching the upper level (175 million) of the range in the
year 2000. In addition, such technological changes as direct
a) Information for this section abstracted from Minerals Facts
& Problems, U.S. Dept. of the Interior, 1970 Edition.
* A table of conversion factors from English to metric units
is presented on page 9-27.
2-1
-------
reduction and associated furnace and casting improvements
leading to continuous steelmaking are expected to lead to
decentralization of the industry and possibly to increase the
demand for steel.
Failure of the steel industry to advance technology
sufficiently to meet the increasingly competitive cost and
quality of other materials such as aluminum and plastics could
lead to diminishing markets, with demand gravitating toward the
low level (130 million) of the forecast range.
In 1968, there were 109 iron ore mines operating in the
United States, 13 of which were underground mines; there were
175 integrated steel plants, 483 steel foundries, and 2200
gray, malleable, and ductile iron foundries. Annual iron ore
production was valued at over $800 million, and revenues of
the steel industry totaled $18,652 million.
Most of the major steel companies own or control domestic
mines that supply at least part of their ore needs. The steel
industry also has invested substantially in iron mines in
Canada, Venezuela, Chile, Brazil, Liberia, and Australia. The
major companies producing iron ore in Canada are owned or con-
trolled principally by U.S. interests.
Overall, captive mines are estimated to furnish about 85
percent of the ore used by the domestic iron and steel industry,
Most of our Nation's iron ore is produced in the Lake
Superior iron mining district in Minnesota and Michigan;
relatively small but significant mines produce iron ore for
2-2
-------
domestic consumption in New York, Pennsylvania, Alabama,
Missouri, Texas, Wyoming, Utah, and California.
About 65 to 70 percent of the Nation's steel industry is
situated in the great industrial complex surrounding the lower
Great Lakes ports in Illinois, Indiana, Michigan, Ohio, and
western Pennsylvania. Large integrated steel mills are operated
in northern New York, eastern Pennsylvania, eastern Maryland, and
the Birmingham district of Alabama; relatively small integrated
steel mills are operated in southern Illinois, Texas, Colorado,
Utah, and California.
Although most of the steel in the United States is produced
in integrated steel plants, these plants are outnumbered by
small secondary steel works. At present, many industries are
remelting steel economically.
Technologic trends in iron mining are significant. Taconite
pellets are replacing conventional iron ores, huge open-pit mines
are replacing the underground mines, and operation is changing
from a seasonal to a year-round basis. Changes in the steel
industry are equally significant. Oxygen furnaces, and to a
lesser degree electric furnaces, are rapidly replacing the open
hearths; continuous casting is reducing recycle scrap, and the
mills are producing more and better steel with fewer men.
Table B-l in Appendix B lists the iron and steel producing
companies and their production rates.
2.2 RAW MATERIALS
Iron is a mixture of iron oxide minerals with varying
quantities of mineral impurities. It retains its identity
through various processing procedures to ultimate use.
2-3
-------
The types of ore mined in the major iron ore districts
are listed in Table 2.1, by mineralogical names. The principal
forms of the iron in these and other ores are listed in
Table 2.2, and distinguishing characteristics of each group
2
are described.
Table 2.1 IRON ORE MINED IN THE UNITED STATES2
District
Type of
ore
Approximate percent of
total tonnage mined
Lake Superior
Birmingham, Alabama
Chattanooga, Tenn.
Adirondack,
Northern N.Y.
Northern N.J. and
S.E. N.Y.
Lone Star, Texas
Iron Mountain, Mo.
Vulcan, Calif.
Cornwall, Penn.
Sunrise, Wyoming
Iron County, Utah
Hematite
Hematite
brown
Brown
Magnetite
Magnetite
Hematite
Brown
Magnetite
Carbonate
84
7
1
4
2-4
-------
Table 2.2 IRON-BEARING MINERALS'
Mineralogical
name
Chemical
name
Chemical
composition
Oxide
Magnetite
Hematite
Ilmenite
Limonite
Carbonate
Chamosite
Stilpnomelane
Greenalite
Minnesota!te
Grunerite
Sulphide
Pyrite
Marcasite
Pyrrhotite
Ferrosoferric oxide
Ferric oxide
Iron-titanium oxide
Hydrous iron oxide
Iron
Silicates
Iron
Sulphide
Fe3°4
Fe20
FeTi
HFe02
FeO(OH)
Various and
sometimes
complex
FeS,
FeS',
FeS'
Hematite, magnetite, and limonite (goethite) ores are
identifiable by color; these mineral ores are called respectively
red, black, and brown ores. Siderite is occasionally identified
as brown ore also.
The term taconite was first used locally in Minnesota to
name hard, siliceous, banded rocks of the local iron-bearing
formations. Over the last 20 years it has come to be used to
identify similar materials in other districts. Table 2.3 gives
a typical analysis of magnetic taconite ore.
2-5
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Table 2.3 ANALYSIS OF TACONITE ORES
Component
Total Fe
Magnetic Fe
Si°2
Mn
A1203
CaO
MgO
P
S
Ti02
Percent
32.0
24.5
45.2
0.3
0.8
2.3
3,0
0.05
0.02
Trace
Soft taconite, from which part of the silica has been leached
by natural processes, is called semitaconite.
Minnesota, the main iron-producing state in the Nation,
has produced over 60 percent of the Nation's iron ore during
the past 85 years. This state has deposits of 45 billion tons
of low-grade magnetic taconite and has limitless reserves of
low-grade nonmagnetic ore.
Contaminants that can be present in iron ore in poten-
tially significant amounts are phosphorous, sulfur, titanium,
vanadium, zinc, copper/ chromium, nickel, arsenic, lead, tin,
.^nd cobalt.
Table 2.4 gives a typical analysis of some of the iron
ores.
2-6
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Table 2.4 IRON ORE ANALYSES
7
Kind
Range
Mesabi
Menominee
Labrador
of ore
Name
Hanna
Weirton
(Michigan)
* • •
Composition
Fe
53.
to
54.
51.
to
54.
48.
29
96
5
90
58
to
55.
51
SiO,
8.04
to
10.01
3.02
to
4.23
3.84
to
6.84
Al 0
0.43
to
0.57
2.17
to
2.61
0.73
to
1.08
CaO
0.15
0.65
0.02
to
0.15
(percent)
MgO
0.10
0.90
0.02
to
0.05
P Mn
0.
0.
0.
0.
0.
0.
041
to
047
464
to
542
054
to
117
0
.39
to
0
0
0
0
4
.60
.17
to
.33
.56
to
.50
In addition to the ore materials, iron production requires
an acid flux such as silica, a basic flux such as limestone or
dolomite, or a neutral flux such as fluorspar. Various ferro-
alloys (as alloying agents) and all types of by-product scrap
are used in steel making. The processes require large amounts
of fuel, mainly coke and oxygen.
A number of metallic elements and compounds may be added
to molten iron or steel to effect specific properties in the
end products. Additives are used to remove gases, decrease
inclusions, counteract harmful effects of sulfur/ or change
the characteristics of the metal.
The more common metal additives are aluminum, chromium,
cobalt, columbium, copper, lead, magnesium, manganese, molyb-
denum, nickel, carbon, phosphorus, boron, tin, titanium,
tungsten, and vanadium.
2-7
-------
2.3 PRODUCTS
The iron and steel industry produces pig iron; various
grades of refined steel in such shapes as billets, blooms, and
ingots; coke; and various chemicals recovered from the by-
product coking process.
Pig iron is the product of the blast furnace formed by
smelting iron ore with carbonous material as the reducing
agent, usually in the form of coke. About 90 percent of the
pig iron produced in the United States is consumed in making
steel; the remainder is used for iron castings.
Cast iron is an iron containing carbon in excess of the
solubility in the austenite that exists in the alloy at the
eutectic temperature. Gray iron is cast iron containing two
to four percent combined and free carbon. Malleable iron is
white cast iron, annealed to graphitize all or part of the
cementite. Ductile iron is cast iron that has been treated
to give the primary graphite a nodular or spheroidal form.
Ingot iron is commercially pure iron made in an open-
hearth furnace. Iron powder is iron in finely divided form,
commonly made by reduction of finely ground oxide or atomization
of molten iron, it can also be made electrolytically.
Steel is a refined iron-base alloy containing up to 2.5
percent carbon. There are six principal types of steels:
1) plain carbon, 2) full alloy, 3) stainless, 4) high-strength,
low-alloy, 5) heat-resistant, and 6) electrical.
Small amounts of gold, silver, sulfur, copper, cobalt, and
phosphate minerals are recovered occasionally as by-products
2-8
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and coproducts during iron mining operations at a few domestic
deposits. Manganese is often a coproduct.
Blast furnace slags are used principally in the con-
struction and maintenance of roads, buildings, railroads, and
airports; for mineral wool manufacture; and to some extent for
agriculture. Steel slags, either alone or in blends with blast
furnace slags, are used similarly.
2.4 PROCESS DESCRIPTION
Figure 2.1 illustrates the processes in the integrated
iron and steel industry, and the major raw materials. As
the figure shows, the principal operations are mining, concen-
tration, agglommeration, pig iron production, steel manufacture,
and by-product coking. The processes within these operations and
their emissions are described in the following sections. Any
extraordinary energy requirements of a process (e.g., high
demands for fuel or electrical energy), are noted.
2.4.1 Mining Operations
Ore is mined either by open pit or underground methods,
depending upon the shape, depth, and attitude of the ore body
being mined.
(1)* Open-pit mining *- Open-pit mining is used whenever the
ratio of overburden to ore does not exceed an economical limit.
Iron mines are responsible for little air pollution other than
*Numbers refer to corresponding processes in Figure 2.1.
2-9
-------
fugitive dust emissions. Transportation of ores also entails
significant emissions of fugitive dust. It is estimated that as
much as two percent of the ore can be lost in transport in
open cars unless dust suppression chemicals are added. Ore is
transported from mines to mills by rail cars, trucks/
truck-trailers, belt conveyors, or combinations of these carriers.
(2) Underground mining - Mining underground requires a larger
investment per ton of annual capacity than open pit mining.
Ores are extracted by several methods, including block caving,
sub-level stopping, sub-level caving, and top slicing.
Ore is transported to the surface by rail trams, trackless
shuttle cars, scrapers, or conveyor belts. The ore is then
transported to the mill in the same manner as the open-pit
mined ore. Fugitive dusts from these transportation operations
are the only significant emissions.
2.4.2 Beneficiation
Iron ores as mined contain approximately 25 to 30 percent
iron; they are concentrated to 60 to 65 percent iron. Some
ores can be concentrated simply by crushing, screening, blending,
and washing. Others, such as magnetic taconites, require grind-
ing and subsequent separation of the iron from other materials
by flotation or magnetic separation. Flotation has been found
effective in the separation of nonmagnetic hematite from
silica. These operations usually occur at the mine site.
(3) Crushing, blending and drying - Iron ores from the mine are
first screened and crushed, then blended. Ores having high moisture
2-10
-------
STUL
BY-PHONIC- COKt PIODUCTION
Y~
V3y
> O O O
Figure 2.1. Iron and steel production.
-------
content are dried before screening. Very little crushing and
blending is done at the blast furnace plant.
In crushing of taconite ores, 15 to 20 percent of the
primary crusher feed is eliminated as tailing and are dumped in
the Great Lakes. Grinding of hard taconite requires about 11
KWH of power per gross ton of primary feed.
Air pollution from crushing and blending operations is
negligible. Dust emissions amounting to 2 pounds per ton of
ore have the same composition as that of the ore being treated.
Mostly they contain Fe^O^ or Fe-0., some silica and limestone.
These operations are not known to create water pollution
problems .
The ore arrives at the plant in railroad hoppers and is
piled by a machine called a stacker. The blended material is
transported by a belt conveyor to a surge bin and then to a
washing plant.
At some plants treating Mesabi range magnetic taconite ore,
the mine run ore containing a small amount of fines and a heavy
proportion of large blocks is brought in and dumped from the
22-ton trucks directly into the top of a crusher installed at
the mine site. The crushed material is conveyed to a surge pile,
from which it is hauled by rail to concentrating plants.
Washing - The iron-bearing minerals are separated from
gangue materials by techniques based on differences in specific
gravity. Many kinds of washers are used to remove sand and clay
by suspending them in the flowing stream of water. The liquid
stream containing gangue material is usually sent to waste water
ponds. No air pollutants are known to be emitted.
2-12
-------
(5) Heavy media separation - Separation is achieved by sus-
pending ore materials in a liquid having intermediate specific
gravity, in which the heavier iron mineral will sink and the
lighter gangue will float to the surface. The waste water,
containing gangue, is sent to a disposal area. No air pollution
emissions result from this operation.
(6) Magnetic separation - Techniques based on magnetic proper-
ties are used to separate magnetic valuables from nonmagnetic
materials. These methods are used mainly with taconite ores.
Table 2.5 gives a typical analysis of taconite ore concentrate.
Table 2.5 TYPICAL TACONITE CONCENTRATE ANALYSIS4
Composition
Fe
Si02
CaO
MgO
A1203
Mn
Percentage
64.55
9.2
0.53
0.67
0.55
0.22
The product is pumped to wet storage, and gangue material
present as slurry is discarded.
Prior to magnetic separation ore drying is often required.
(7) Flotation - Flotation techniques are also used to separate
valuable ore-bearing minerals from the gangue. Various frothers
(e.g., fatty acids, soaps, alkyl sulfates) are added to aid in
the separation.
2-13
-------
Waste water containing frothing agents and gangue from this
process and other beneficiating processes can present serious
pollution problems. For example, high concentrations of asbestos
fibers found in the drinking water supply in Duluth, Minnesota
are believed to be due to the waste water from taconite ore
mining and beneficiation processes. The taconite processing
company, who has been charged by EPA to be responsible for the
release of asbestos fibers, maintains that their present dis-
posal system poses no threat to human health or environment.
They have, however, developed an alternative plan under which
tailings would be pumped far below the surface of Lake Superior,
q
where they would form an underwater sand reef. It is argued
that this method is unsatisfactory because the tailings would
still enter and pollute the Lake. Ore-dryer before beneficia-
tion also creates air pollution problems.
The materials handling and stockpiling operations associ-
ated with the beneficiation processes and also the stockpiling
of raw materials create significant emissions of fugitive dust.
Dusts from stockpilings consist of oxides of iron, silicon,
calcium, and magnesium from iron oxides; carbonates of calcium
and magnesium, magnesium oxide, and silica from limestone and
dolomite; calcium fluoride, calcium carbonate and oxides of iron,
aluminum, and silicon from fluorspar, which is used as the
fluxing agent. The tailings can also present significant problems
of solid waste disposal, although most of these are related
either to fugitive dust emissions or to contamination of ground
or surface waters.
2-14
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Total mill tailings flow by gravity to the tailings pond.
Coarse tailings are removed and treated in a hydroseparator
and a thickener. Overflow from the thickener may be pumped back
to the concentrating plant.
Dust emissions from tailing piles are estimated to be 4 to
16 tons/acre-year, depending upon climatic factors; for stock-
piling of aggregates, the estimates range from 10 Ib/ton-year
for fine sand to 1.5 Ib/ton-year for crushed rock.
Final concentrate is conveyed on belt conveyors to storage
and is transported to iron and steel refining units by boat,
barge, and railroad. Trucks are also used occasionally. Mostly
the material is stored (stockpiled) at agglomeration units.
Overhead clam bucket gantries, bottom cars, belt conveyors and
gravity chutes are used for transporting the material from
stockpiles. Stackers and shovels are used for loading purposes.
2.4.3 Agglomeration
Ores are agglomerated to produce suitably sized blast
furnace feed. The four major process options for ore agglomera-
tion are sintering, pelletizing, nodulizing, and briquetting.
Of these, sintering and pelletizing are by far the most common,
with sintering predominant. Pelletizing is usually done near
the mine site, whereas sintering is performed at the steel mill.
(8) Sintering - The sintering process fuses various types of
fine materials (e.g., iron ore, collected fumes) into an agglom-
erated mass of suitable size and strength to serve as blast
furnace feed. Sintering plants range from 2000 to 6000 tons
per day capacity.
2-15
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Most of the iron ore in the northeastern United States is
concentrated or pelletized at the mine site only. Table 2.6
gives average grade of sinter and pellets produced in the
northeastern states in 1968.
Table 2.6 AVERAGE GRADE OF SINTER AND PELLETS PRODUCED IN 1968
NORTHEASTERN IRON ORES (DRY BASIS)10
Benson
Sinter
Benson Non-
Bessemer
Sinter
Port Henry
Sinter
Cornwall
Pellets
Morgantown
Pellets
(Grace
Mine)
Fe
63.91
62.60
66.17
64.92
65.83
P
0.026
0.199
0.140
0.006
0.010
Si02
5.47
4.31
3.94
3.30
3.18
Mn
0.30
0.16
-
0.08
0.08
A12°3
3.02
2.74
1.22
1.50
0.61
CaO
1.39
1.28
1.16
0.90
0.55
MgO
0.26
0.26
0.26
1.50
1.54
S
0.030
0.030
-
0.009
0.009
The mixture of iron ore fines or concentrates and coke fines
is deposited on a traveling grate. The mixture is ignited by
natural gas or fuel oil, burns, and forms a fused mass, which
is subsequently fed to a cooler, then crushed, and screened.
The sintering process is a significant source of potentially
hazardous emissions. The process emits not only sulfur oxides
(about 30 to 40 percent of the sulfur in the charge is liberated),
but also other volatile constituents. Particulate emissions are
2-16
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estimated to be about 42 pounds per ton of sinter. In 1969, total
particulate emissions from sinter operations were over 100,000
pounds per year. Table 2.7 gives a screen analysis of
particulate emissions from a sintering machine.
Table 2.7 PARTICLE SIZE ANALYSIS OF PARTICULATE
EMISSIONS FROM A SINTERING MACHINE
Screen size,
microns
5
10
20
30
44
Weight retained,
percent
25.1
47.6
14.6
5.8
5.0
Cumulative Weight,
percent
25.1
72.7
87.3
93.1
98.1
Volumetric flow rate of gases released is approximately
1.5 to 2.0 scfm/lb per hour of sinter. These gases generally
leave the machine at a temperature of 400°F or lower.
Emissions from the cooler range from 0.2 to 0.25 scfm
per hour of sinter capacity. Therefore, the total stack gas
flow from sinter plants can be expected to range from 1.7 to
14
2.3 scfm/lb per hour of sinter product.
Gas velocity from a sinter machine of a typical plant is
6.42 ft/second. In addition to sinter machines and sinter
screens, all conveyor transfer points, loading points, chutes,
and bins handling sinter are potential sources of fugitive dust.
Many industries control the dust from these points by using a
chemical wetting agent mixed with water.
2-17
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(9) Pelletizing - Palletizing is used primarily for taconite
ores. The ore is ground, mixed with water and binder, and
rolled into small balls. These "green" pellets are first dried,
then heated to between 2200 and 2500°F to bind the small par-
ticles, and finally cooled. Control of moisture content of
pellets is very important to insure strength. Normal moisture
content runs between 10.0 and 10.25 percent. The pellets are
conveyed through a weight meter to storage. Magnetite taconites
are concentrated and agglomerated at several locations in
Minnesota. Table 2.8 gives the compositions of taconite
pellets produced at some of these locations.
Table 2.8 COMPOSITIONS OF PELLETS
PRODUCED FROM CONCENTRATES ORIGINATING
WITH MAGNETITE TACONITES (1968)*4
Minntae
Pellets
Reserve
Pellets
Erie
Pellets
Eveleth
Pellets
Birch Lake*
Pellets
Fe
65.12
62.56
63.91
65.39
62.48
P
0.011
0.028
0.012
0.012
0.023
Si02
5.50
8.76
7.22
5.50
9.00
Mn
0.16
0.27
0.23
0.14
0.22
A1203
0.42
0.47
0.31
0.29
0.54
CaO
0.25
0.44
-
0.19
0.50
MgO
0.59
0.51
-
0.30
0.65
S
0.002
-
-
-
—
*Dry basis.
2-18
-------
Total particulate emissions from pellet plants are 80,000
tons/year. Since the concentrates received at pelletizing
plants are usually moist, dust generation from handling is not
a significant problem.
(10) Briquetting - In the briquetting process/ ore fines are mixed
with a binder and formed into compact masses between two rotating
rolls. Alternatively, the ore may be heated to between 1200
and 1800°F and then briquetted while hot.
(11) Nodulizing - In the nodulizing process ore fines are heated
in an oil- or gas-fired rotary kiln. The material moves through
the kiln and is agglomerated into lumps by the rolling of the
charge at temperatures near the fusion point of 2300 to 2500°F.
The ore balls form nodules, which are then discharged and cooled.
Fuel consumption during nodulizing ranges from 2 to 4 million
BTU/ton. Table 2.9 gives typical operating statistics of
nodulizing at one plant and Table 2.10 gives chemical analysis
of the nodulized product of the plant.
Table 2.9 TYPICAL OPERATING STATISTICS16
Optimum nodulizing temperature, °F
High-silica ore as charge 2300-2380
Low-silica ore as charge 2450-2500
Magnetite as charge 2300-2350
Temperature of nodules discharged
from cooler, °F 70- 300
Coal consumption, pounds per long ton
of nodules 175.66
Fuel consumption, BTU/ton of nodules:
For low-silica ore 2,400,532
For magnetite 1,846,000
Power requirements,
KWH/ton of nodules 16.2
2-19
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Table 2.10 CHEMICAL ANALYSIS OF NODULIZED
PRODUCT, AVERAGE16
(Values in percent)
Moisture
Fe
sio2
Mn
P
CaO
From low-silica
ore
0.16
63.23
5.63
0.34
0.054
2.19
From taconite
concentrate
0.12
62.99
7.33
0.29
0.020
2.44
Exit gas temperature of the kiln is 530 to 580°F, and
stack gas temperature of the cooler vent is about 150 to 300°F.
The agglomerated product is stockpiled. From storage, it
is moved to surge hoppers at the blast furnace, where it is
weighed and transferred to the top of the blast furnace by skip
hoist or by belt conveyor. The flux material is transferred
to the surge hoppers by dump cars.
No data were found on emissions from briquetting or
nodulizing processes. The potentially hazardous emissions
should be less than those from the sintering process, because
the mass of material is not heated to as high a level as in
sintering.
2.4.4 Pig Iron Production
12} Blast furnace - The blast furnace reduces the iron ore to
produce pig iron. Iron-bearing materials (iron ore, sinter
pellets, mill scale, open hearth or basic-oxygen-process slag,
iron or steel scrap), coke, and fluxes are charged into
2-20
-------
the top of the furnace along with heated air. In some instances
fuel oil or powdered coal is blown into the bottom. The furnace
operates at about 2800°F, with the blest temperature automatically
controlled. Many furnaces at present operate at pressures of
about 10 psi. The iron ore descends down the furnace and is
reduced and melted by the countercurrent flow of the hot reducing
gases created by the partial combustion of coke.
Approximately 1000 pounds of coke are required to produce
1 ton of pig iron. Natural gas or fuel oil may also be re-
quired, depending on the nature of the charge.
The molten iron is collected in ladles. The hot molten metal
typically contains 4 percent C, 1 percent Si, 0.03 percent S, and
1 percent Mn. Slag is flushed from the furnace and is handled
in one of three ways: (1) it flows directly into ladles; (2) it
is granulated; or (3) it flows directly into cooling pits.
Sometimes molten slag of suitable composition is dumped into a
specially prepared dump. After weathering for a period of
several weeks, it is removed, screened, and sold as aggregate.
Table 2.11 lists typical approximate inputs and outputs of
a blast furnace, and Table 2.12 gives a typical analysis of
the limestone used in blast furnaces.
Particulate emissions from blast furnaces are minimal,
since a high degree of particulate emission control is necessary
to keep the stoves (heat exchangers) from plugging. Without
controls, about 150 pounds of particulate per ton of product
18
is emitted. Blast furnace slips, which create emissions that
2-21
-------
Table 2.11 BLAST FURNACE: INPUT AND
OUTPUT MATERIALS
Material
Weight, tons
Input Materials
Ore and other iron-bearing materials
Coke or other fuel
Limestone or dolomite
Air
Materials Produced
Iron
Slag
Flue dust
Blast furnace gases
1.7
0.50 to 0.65
0.25
1.8 to 2.0
1.0
0.21 to 0.40
0.05
2.5 to 3.5
Table 2.12 ANALYSIS OF LIMESTONE
7
FROM COLUMBUS, OHIO
Constituent
Si00
2
A12°3
CaO
MgO
p
s
Percent
0.06
0.04
30.83
22.27
-
0.020
2-22
-------
bypass the control devices, rarely occur. Table 2.13 presents
composition data for collected blast furnace dust; Table 2.14
gives a size analysis of the dust. The collected dust is
usually utilized as feed to the sinter machine.
Table 2.13 CHEMICAL ANALYSES OF DRY, BLAST-
FURNACE FLUE DUST7
Weight Percent
n.a. - not available.
Component
Fe
FcO
SiOo
Al.,0^
MgO
CaO
Na2O
K20
ZnO
P
Si
Mn
C
Range for Several Plants -
36.5 - 50.3
n.a.
8.9 • 13.4
2.2- 5.3
0.9- 1.6
3.8- 4.5
n.a.
n.a.
n.a.
0.1- 0.2
0.2- 0.4
0.5- 0.9
3.7 - 13.9
Midwest Plant
47.10
11.87
8.17
1.38
0.22
4.10
0.24
1.01
0.60
0.03
n. a.
0.70
n.a.
Table 2.14 SIZE ANALYSIS OF FLUE DUST FROM U.S. BLAST FURNACES12
Size
U S Secies
20
30
40
50
70
100
140
200
-200
Microns
833
589
414
295
208
147
104
74
-74
Range, percent
2.5 - 20.2
3.9 - 10.6
7. 0 - 11.7
10.7 - 12.4
10.0 - 15.0
10.2 - 16.8
7.7 - 12. 5
5.3- 8.8
15.4 - 22.6
2-23
-------
Slag from blast furnaces can create significant problems of
solid waste disposal. Quenching or granulation of slag can also
cause air pollution, since the sulfur trapped in the slag reacts
to form hydrogen sulfide. It is conceivable that other reactions
may also liberate some of the more volatile constituents.
Although slag quenching may entail water pollution problems,
these were not assessed. About 650 pounds of slag are produced
per net ton of hot metal. Table 2.15 gives a typical slag
analysis.
Table 2.15 SLAG ANALYSIS7
Constituent
Si°2
A1203
CaO
MgO
S
Fe
Mn
Percent
35.8
9.0
39.8
12.9
1.92
0.25
1.2
Slag is a useful by-product of iron making, occurring in
three forms whose physical structure depends on the method of
cooling: these are hard, granulated, and expanded slags. To
suppress the hydrogen sulfide pollution from expansion of slag,
the Alan Wood Steel Co. of Conshohocken, Pa., investigated a
new process called "pelletizing", originally developed by
National Slag Limited of Canada. The method involves a rapid
accumulation of slag at the point of cooling.
19
2-24
-------
About 6 tons of gases are evolved for every ton of iron
produced from the blast furnace. Table 2.16 gives a typical
analyses of these gases. Heating value of the raw gas is 90
BTU/ft and the moisture content is 2 percent. The dust concen-
tration is 12 grains/ft as the gases leave the furnace.
Table 2.16 ANALYSIS OF FURNACE GAS7
Constituent
CO~
2
CO
H_
2
CH4
Percent
15.8
25.6
3.0
55.6
Part of this gas is used for heating purposes. The gases leave
the furnace at ter.peratures of 350 to 540°F and at a flow rate
of about 0.508 scfm/lb per hour of pig iron produced (approxi-
mately 110,000 to 150,000 ft per ton of pig iron produced).
The actual flow rate of the gases is a function of the coke
feed rate. Total gas volume increases linearly with the
increase of the coke feed rate.
The combustion products of the blast furnace range from
1.2 to 2.8 pounds of combustion gas per pound of pig iron.
Waste water from the blast furnace includes furnace cooling
water for cooling the blast air and the process wash water. The
furnace cooling water leaves the furnace essentially as received
except for the heat added. The gas wash water dissolves con-
taminants in the vapor phase, including ammonia, phenol, cyanide,
and carbon monoxide. The wash water dissolves alkali (sodium
and potassium bicarbonates) and other contaminants.
2-25
-------
Coke and limestone used in blast furnaces are not stored
near the furnace, but are used directly as they are received.
Charging of the furnace is automatically controlled.
Hot metal from the furnace is poured into torpedo cars
and weighed on the hot metal track scale. After the metal is
transferred to a charging ladle, a crane transports it to the
steelmaking vessel.
2.4.5 Steel Manufacture
Pig iron is refined into steel in steel furnaces by reduc-
ing the level of impurities and adding alloying compounds.
Molten steel from the furnaces is cast and formed into the
desired shapes. The products are then subjected to finishing
operations.
Three types of steel furnaces are in use: open-hearth,
electric, and basic oxygen. A significant number of open-hearth
and electric furnaces also incorporate oxygen lancing because
it permits higher production rates. The four major phases of
furnace operations are charging, melt-down, refining, and
pouring.
Atmospheric emissions vary substantially among these phases
of furnace operation and are greatly increased by the use of
oxygen lancing. From the standpoint of potentially hazardous
emissions, however, the composition of furnace emissions is
primarily a function of the grade of steel being produced (i.e.,
the amount and type of alloying compounds charged to the
furnace) and the scrap metal charge.
2-26
-------
(13) Electric furnaces - Electric furnaces are usually used to
produce high-alloy steels, although they also produce a con-
siderable amount of mild steel. Oxygen lancing is often used
to increase production rates. The electric furnace requires
about 400 to 425 kilowatt-hours of power per ton of steel
produced.
Particulate emissions from electric furnaces consist
primarily of oxides of iron, manganese, aluminum, and silicon.
The uncontrolled particulate emission rate is approximately
9 pounds per ton of metal without oxygen lancing and about 11
pounds per ton of metal produced with oxygen lancing. Other
emissions include gaseous fluorides at 0.012 pound per ton and
particulate fluoride at 0.238 pound per ton of metal produced.
About 18 pounds of carbon monoxide gas is emitted per ton of
metal produced.
As stated previously, emission composition is dependent
upon the type of steel produced. Tables 2.17 and 2.18 present
typical data on composition of emissions from electric furnaces.
Approximately 800 to 1200 gallons of water per minute are
used to cool the equipment. Little contamination of the water
is encountered. Occasionally, extremely high contents of
suspended solids, on the order of 5000 ppm, may be present.
Charging cranes bring the raw material in buckets placed on
scales. Blower trucks are used to push the lime, coal, and
dolomite (the bulk additives) into storage tanks. Buckets are
used to move these materials into the furnace.
2-27
-------
Table 2.17 CHEMICAL COMPOSITIONS OF ELECTRIC-
12
FURNACE DUSTS
(Percent by weight)
Element or
Compound
FeO
Fe203
Cr203
MnO
NiO
PbO
XnO
SiOz
A1203
CaO
MR0
S
P
C
Alkalies
Sample Designation
A
4.2
35.04
o.oo
12. 10
0.30
n. a.
n, a.
8. 80
12.90
14.90
7.90
0.26
0. 10
2. 30
1.20
B
n. a.
50.55
0.56
12.22
n. a.
n. a.
n. a.
5.76
5. 85
2.60
7.78
tr
0.28
n. a.
4.76
C
n. a.
52.62
0.00
5.34
tr
3.47
8.87
6.78
2.55
6.72
3.49
0.59
n. a.
n. a.
n. a.
D
n. a.
52. 05
0. 15
1.29-2. 58
tr
0.81-1. 08
1.24-2.48
3.85
14. 61
1.40-4.20
1.66-4.98
n. a.
ri. a.
n. a.
n. a.
E
n. a .
50. 05
13. 87
n. a.
3. 18
n. a.
n, a.
5. 50
n. a.
9. 80
6. 64
n. a.
n. a.
n. a.
Z. 50
F
4 - 1C
I 9 - u
0 - \l
3 - 11
0 - 3
0 4
0 - 44
2-9
1 - IJ
5 - 22
2 - IS
0 - 1
0 - 1
i - 4
I - 11
Note: 11.n. - nor available, tr - trace
Sample A - f •'.}'' ?0 ,1 furnace. Plant specializing in tool and die steels.
Sample B - Representative sample from plant with four 75-ton and two 200-ton furnaces producing
low -alloy and stainless steels.
Sample <^ - Single 100-ton furnace producing low-alloy steels for plate.
Sample D - Single 100-ton furnace producing low-alloy steels for plate.
Sample E - Single 70-ton furnace producing stainless steel.
Sample F - Representative samples from multiple-furnace shop. Furnaces vary in size from •) to "Oo-ton, pro
low-alloy and stainless strc-ls.
Table 2.18 CHANGES IN COMPOSITION OF ELECTRIC-
FURNACE DUST DURING A SINGLE HEAT
12
PI.' riot!
\u-itiuh
O r <-• ; ) .x i cl a t i < > n
O.xv^on lancing
i\ t/'f mi nt>
Fe203
56. 75
66. 00
65. 37
26.60
Com
c 1-203
1.32
I. 32
0.86
0.53
MnO
10. 15
5.81
9. 17
6. 70
position, weight percent
Si02
9.77
0.76
2.42
Tr
CaO
3.39
6.30
3. 10
35.22
MgO
0.46
0.67
1.83
2.72
A1203
0. 31
0. 17
0,. 14
0.45
P205
0.60
0. 59
0. 76
0. 55
SO2
2. 08
6. 00
1.8-4
7. 55
2-28
-------
(14) Open-hearth furnaces - Open-hearth furnaces account for
a decreasing percentage of steel production because their
production rates are low. Although oxygen lancing is widely
used to increase production rates, electric furnaces and basic
oxygen units are preferred, because of overall economy. A EOF
can produce 300 or more tons of steel per hour as compared with
the 7 to 10 hours required by an open-hearth furnace.
The finishing temperature of steel in an open-hearth steel
heat is about 2900°F. About 4 million BTU/ton of metal produced
are required, the heat usually supplied by combustion of fuel oil
or natural gas. Fuel consumption decreases considerably when
oxygen lancing is used.
Emissions from open-hearth furnaces consist of particulates
and fluorides. Fluoride emission rates depend on the fluorspar
content of the ore. Uncontrolled particulate emissions from a
furnace without oxygen lancing are about 8.3 pounds per ton of
product; with oxygen lancing, emissions range from 9.3 to 22.0
pounds per ton. These emissions include 0.10 pound of gaseous
fluoride and 0.03 pound of particulate fluorides per ton of
product. Table 2.19 presents data on chemical composition of
particulate emissions.
The flow rates of gases range from 10,000 to 75,000 scfm.
The temperatures of gases range from 460 to 1800°F, and gases
must be cooled before entering air pollution control equipment.
Large quantities of water are required for cooling,
generally ranging from about 750 gpm for small furnaces to
as much as 1500 gpm for larger units. The water is acidic,
and most of it is recovered. The only water loss is that
2-29
-------
Table 2.19 CHEMICAL COMPOSITIONS OF OPEN-HEARTH
PARTICULATE EMISSIONS, OXYGEN LANCING X
(Percent by weight)
1 U-nifiit
or
( oiii|>otmd
Kc.,0-,
I-VO
Tuial f'c
SlOo
AI'jO;)
CaO
Mi?0
Mill)
Ma
(tiO
Oi
/.ilO
/.u
I'K>
I'h
SnOo
i r
Nt
!..,(•»,.
1'
.,
Alkalies
U.S. Steel Corp.
Edgar Thomson
89.07
1 87
63.70
0.8'J
0.52
0.35
n.a.
0. 03
n.a.
u . a .
n.a.
n.a.
1.70
n.a.
.0.50
n.a .
n.a.
n.a.
0.47
n.a.
0.40
1.41
Homestead
88.70
3. 17
n.a.
0.92
0.67
1.06
0.39
0.61
n.a.
0.14
n.a.
0.72
n.a.
n.a.
n.a.
n.a.
n.a
u. a.
1.18
n.a.
0.92
n.a.
Steel Co. of Canada
Hilton Works
n.a.
n.a.
63.5 - 68.0
1.16- 1.56
0.15 - 0.44
0.68 - 1.06
0.32 - 0.44
n.a.
0.43 - 0.55
n.a.
0.11 - 0.16
0.26-2.04
n.a.
n.a.
0.05 - 0.95
n.a.
0.06 - 0.11
0. 03 - 0. 05
n.a.
0. 06 - 0. 12
0.34 - 0.70
0.56 - 1.71
United Kingdom
United Steel Co
88.5
2.2
n.a.
0.4
0.4
0.9
1.5
n.a.
n.a.
n.a.
n.a.
n.a.
n.a.
n.a.
n.a.
n.a.
n.a.
n.a.
n.a.
0.3
1.4
n.a.
Germany
Uillingcn
79.65
0.31
55.1)0
0.47
0.52
0.88
1.86
O.til
n.a.
n.a.
n.a.
n. a
n.a.
n.a.
n.a.
n.a.
n.a.
n.a.
1.52
n.a.
2.69
2.72
U. S. Plant a
n.a.
n . a .
5:),. 10
'J Ou
0.-18
1 . iTj[)
1 . ] 'J
u. a .
O.'JS
n.a.
0. ()-'.
n.a.
0-3.0
n.a.
n . a .
n.a.
n.a.
0. 07
n.a.
U. 15
2.78
<>.fce
- data not available.
a) Average for U.S. Plant.
2-30
-------
associated with collected sludge. The other source of waste
water is the blowdown from the waste heat boiler.
The material to be charged to the furnace is loaded in
charging boxes and moved to the furnace on diesel locomotives
operating on broad-gauge track laid close to the furnace.
115) Basic Oxygen Furnaces - The basic oxygen process is being
used increasingly because of its high production rates. It
converts the hot metal into steel by oxidation of carbon, phos-
phorus, silicon, sulfur, and other impurities in the iron.
Table 2.20 gives typical operating data for a basic oxygen
furnace. The furnace is charged with scrap (30%), molten
iron (70%), and fluxes, chiefly burned lime and fluorspar.
Oxygen is blown into the charge under pressure (generally from
140 to 180 psi) to oxidize the carbon, silica, phosphorus, and
sulfur. When the flow is completed, the steel is tapped into
a ladle. Alloying materials are added to the ladle. The basic
oxygen process requires no external source of heat.
Table 2.20 OPERATING DATA FOR BASIC OXYGEN FURNACE
17
Capacity, ton/melt
Oxygen lance rate, Ib/hr
Oxygen lance rate, scfm
Operating cycle, minutes
Charge scrap
Charge hot metal
Charge lime
Blow
Sample
Finish blow
Top
Pour slag
Idle
Small
Large
140
85,000
16,800
250
152,000
30,000
50
5
3
1
20
3
2
3
3
5-10
Throttled flow
Full flow to scrubber
Throttled flow
2-31
-------
The particulate emission rate is so high that all basic
oxygen units eventually must install high-efficiency particulate
control devices. About 51 pounds of particulate are produced
per ton of product, and about 0.20 pound of gaseous fluorides
per ton. Tables 2.21 and 2.22 give the chemical composition
of dust from a basic oxygen furnace.
Table 2.21 CHEMICAL COMPOSITION OF BASIC OXYGEN FURNACE STEEL-
MAKING DUST FROM THREE TYPICAL U.S. PLANTS, WEIGHT PERCENT12
Element or
Compound
Fed
Fe203
Fe
Mn3O4
Mn
Sl°2
A1203
CaO
MpO
b
P
PZOS
Cu
Zn
Typical
1. 5
90. 0
n. a.
4. 4
n. a.
1. 25
0. 2
0. 4
0. 05
n. a.
n. a.
0. 3
n. a.
n. a.
EOF
U.
n. a.
80. 00
n. a.
n a.
0. 35
2. 00
0. 15
5. 10
1. 10
0. 12
0. 10
n. a.
0. 04
Trace
Dust from
S. Plants
n. a . n. a.
n . a . n . a .
56.0 57.68
n . a . n . a .
1.2 1. 54
1.9 1 . 29
0. 4 0. 13
3.1 3. 59
n. a. 0. 63
0. 09 0. 12
0. 2 0. 09
n. a. n. a.
0. 03 n. a.
1,93 4.80
Note: n.a. - data not available.
Table 2.22
VACUUM-TREATED STEELS
DUST AND METAL ANALYSES FOR
12
Material
Steel in ladle
t^,- ^
Steel in ladle
Dust
Elements, weight percent
C
0.33
1.66
0.33
1.69
Mn
0.73
46.30
0.83
47.70
Si
0.25
1.63
0.26
1.40
Ni
2.86
0.38
0.17
0.13
Cr
0.99
0.36
1.01
0.38
V
0.22
0.01
0.23
0.04
Mo
0.53
0.05
1.21
0.09
Cu
0.17
1.60
0.14
1.20
Fe
17.60
15.50
2-32
-------
In operation of basic oxygen furnaces there is a possibility
of formation of flaking black material called "kish" as an
emission. Kish forms spontaneously whenever hot metal with
carbon content greater than 4.5 percent is cooled below the
2
liquidous temperature. This results in the formation of solid
21
Fe^C, which is unstable and decomposes into graphite and iron.
Usually the kish is formed when the hot metal is transferred
into and out of the ladle.
Gas effluents ranging from 200,000 to 1,200,000 acfm are
emitted from the basic oxygen furnace at temperatures between
3000 and 3500°F. These gases carry 300 pounds or more of oxide
dust per minute. Most of the dust is very finely divided,
23
ranging in size from 0.1 to 1 micron. About 40 to 70 pounds
22
of Fe^O are ordinarily collected per ton of steel produced.
Table 2.23 CALCULATED GAS COMPOSITION FOR 100-TON EOF
BLOWN AT 12,000 SCFM O RATE FOR 20 MINUTES "*
CO
co2
°2
N2
Total
Com-
bustion
Air
Induced
Converter emissions
Total/heat
- .0
11,800
2,800
14,600
Open
Tight
SCF
161,000
24,000
185,000
1,426,000
114,200
'eak rate
SCFM
24,000
0
24,000
Peak gas flow
rates after
combustion,
SCFM
Tight hood
(10% con-
bustion)
21,600
2,400
0
4,510
28,510
5,710
Open hood
(20% excess
air)
0
24,000
2,400
54,150
80,550
68,550
Peak hood gas flow rates, ACFM
Lower portion
of hoods
Tiqht
at
32POF
152,000
16,900
0
31,800
200,700
Open
at
400QF
0
206,000
20,600
165,000
691,600
Leaving hoods
Tiqht
at
1800F
94,000
10,400
0
19,600
124,000
Open
at
3000F
0
160, ono
16,000
361,000
537,000
2-33
-------
Concentrations of dust during the blow are reported to be
from 6 to 15 gr/scf.
(16) Degassing - Degassification of molten steel under vacuum
improves its physical properties. The liquid steel may absorb
gases, particularly hydrogen, from the atmosphere and raw materi-
als. Oxygen and nitrogen combine with alloying elements to
form oxides, cyano-nitride, or nitride compounds. All of these
impurities are removed by vacuum degassing, which is done by
three methods: stream degassing, circulation degassing, and
ladle degassing. All of these methods cause emission of gases
containing CO, C09 and H9. Nitrogen and argon are present in
«£ £•
the offgases from air in the system. Water vapor is also
present. Particulate is emitted from the operation.
2.4.6 Casting and Finishing Operations
(17) Casting and finishing operations - The molten degassed
steel either is cast continuously into products of the desired
shape or is cast into ingots for subsequent forming. Before
steel can be rolled, surface defects must be removed by scarfing,
Jets of oxygen are directed at the surface of the steel, which
is maintained at high temperatures, causing localized melting
and subsequent oxidation of the steel. The steel products are
then subjected to a number of finishing operations such as
pickling.
Atmospheric emissions occur as a result of pouring steel
into the molds, volatilization of the mold coating compounds
and hot-tops, and addition of volatile metals to the mold,
such as lead in the production of leaded steel. Emissions
2-34
-------
from the rolling operation are minor. potentially hazardous
emissions from steel scarfing may be significant depending
upon the type of steel.
Pickling entails no significant atmospheric emissions;
it can cause serious water pollution, however, since pickling
is a treatment of steel in an acid bath to remove oxide from
the metal surface. Both sulfuric acid and hydrochloric acid
are used in the baths. Discharge from the pickling operation
generally includes spent strong pickle liquor and acidic rinse
water, which must be neutralized before it can be safely dis-
charged.
2.4.7 Coking
Coke is the major fuel and reducing agent used in the blast
furnace to produce pig iron. Over 98 percent of the total pro-
duction of metallurgical coke is made by the by-product process.
During manufacture and processing of coke by-product emissions
are generated by the coke oven and the by-product chemical
recovery unit. Figure 2.1 shows the coke oven and the chemical
recovery unit. A more detailed schematization of coke plant
operation is shown in Figure 2.2.
(18) Coke oven - The coking operation includes: (1) coke
handling, (2) oven charging, (3) oven operation, pushing and
quenching, and (4) coke production. The coke produced contains
typically 5 percent moisture, 0.8 percent volatile matter, 89.7
percent fixed carbon, 9.5 percent ash, and 0.9 percent sulfur.
Emissions from coal handling are primarily fugitive dust
occurring at the coal storage operation and subsequent transfer
2-35
-------
oid Tar
Tor
Decontjr
F!L
TO
r,?
k
^_
L'QbOr
TS'
p*-
-
Gcs
Coiiec'ini)
Mam
Gos
Pnmcry
Coo e'i
1
i
__C
S'ea
Turbin
_s
r
e
Gas
0'
— _
1
Breeze
Ovens
Co»«
fS-.on
Vi;-:9
Cool
C'jke
Pollution
To
To Wcslc
-To \
Benzol
P'oit
Figure 2.2 Coke plant operation.
24
2-36
-------
points. Emissions are on the order of 10 pounds/year-ton of
material stored. During the charging operation, smoke, tar
vapors, and gases are formed by the pyrolysis of coal and dis-
charged through open charging ports. Atmospheric emissions
during pushing are due to the smoking of incompletely coked coal
and the entrainment of coke particles in thermal updrafts
created by the hot coke discharged from the oven. Coke
particles are also entrained in the steam plume resulting from
coke quenching. Furthermore, waste waters from the by-product
recovery plant, containing phenols, ammonia, and undoubtedly
many other contaminants, are often used for quenching the hot
coke. Thus the coke-quenching operation is a source of potentially
hazardous emissions. The burning of coke oven gas for under-
firing the ovens is a source of sulfur oxide emissions. Vir-
tually all of the sulfur present in coke oven gas is present as
hydrogen sulfide, approximately 3.5 to 4.5 grams of hydrogen
sulfide per cubic foot of coke oven gas. A few plants remove
70 to 90 percent of the hydrogen sulfide from coke oven gas.
Wastes from the coke plant are segregated in a separate circu-
lating system with the exception of the ammonia-still waste,
which contains about 10 ppm of phenols and is sent to the waste
treatment plant for disposal. An average of 12,000 ft of gas
is produced per ton of coal coked, along with 10 gallons of tar,
35 gallons of light oil, and 19 pounds of ammonium sulfate.
The by-product processing operation entails a variety of
steps, any of which, such as thiocyanate discharge, can create
potentially severe water pollution problems.
2-37
-------
Barges bring the coke to the unloading dock at the coke
plant and deliver it to stock pits through belt conveyors. A
bull-dozer loads the material into a track hopper.
After quenching and cooling, oven coke is discharged onto
coke wharves, then conveyed to screening units. Railroad cars
move the furnace coke to blast furnaces.
(19) By-product chemical recovery unit - The gases produced in
coke ovens contain many valuable chemicals that may be recovered.
These include ammonia, benzene, xylene and toluene, phenol, and
napthalene. As a part of recovery operations, the gases are
first washed with water to produce a weak ammonia liquor. This
liquor is very high in ammonia chloride and contains phenol,
cyanide, and thiocyanates. Sources of contaminated waste
liquor include discharge from ammonia, phenol, and benzol
recovery operations. These wastes contain phenol, ammonia,
24
chloride, and light oil. In 1973 only one company in the
United States recovered sulfur as a by-product from coke industry
Table 2.24 gives emission factors for by-product coke manufac-
turing without controls.
2.4.8 Direct Metal Reduction Processes
Many direct reduction methods are in current operation,
most of them in Europe. The direct reduction method bypasses
the blast furnace. Two plants are under construction in the
United States for production of iron by different direct-
reduction processes. Data on the amount and characteristics of
emissions are not yet available.
2-38
-------
Table 2.24 EMISSION FACTORS FOR BY-PRODUCT COKE MANUFACTURE WITHOUT CONTROLS
NJ
I
U)
Particulates
Typo of operation Ib/ton | kg/IVIT
By-product coking'
Unloading
Charging
Coking cycle
Discharging
Quenching
Underfiringd
0.4
1.5
0.1
0.6
0.9
0.2
0.75
0.05
0.3
0.45
Sulfur
dioxide
Ib/ton
-
0.02
-
-
-
4
kg/MT
-
0.01
~~
~
~
2
Carbon
monoxide
Ib; ton
-
0.6
0.6
0.07
-
kg/Ml
-
0.3
0.3
0.035
-
Hydrocarbons'1
Ib/ton
-
2.5
1.5
0.2
-
kg/MT
1.25
0.75
0.1
-
Nitrogen
oxides (NO?)
Ib/tonTkg/MT
0.03
0.01
-
-
-
0.015
0.005
-
-
Ammonia
lb;'ton j kg/MT
-
0.02
0.00
0.1
-
-
0.01
0.03
0.05
-
Emission factors expressed as units per unn weight of coal charged.
Expressed as methane.
L 5. The lulfur dioxide factor is bdsed on the following representative conditions: !1) sulfur content of conl r^ar()''ft to ovun is 0.8
pnrcen; by v\'f*iyht; 12! auoul 33 pcrcenx by weujht of total sulfur in the coal charged to oven is transferred to the coke-oven r,as. (31 about 40
percent of coke-oven gas is burned rlur mq the underf inng operation and the remainder is used m other parts of tne steel operation vvhere the rest of
ihe iulfur riioxirie is disch.irgL'd about G 'h ton !3 ky.-MT) of coai charged; iJnd (4) ass used in underlying hds not bf.'('n dpsu! '-n' i::i'd.
-------
2.5 MAJOR POLLUTANT SOURCES
Though most of the processes in the industry could be
major sources of pollution if uncontrolled, sintering and
by-product coke ovens represent the most significant emis-
sions sources from the purview of tonnage emitted and emis-
sion characteristics. The pollution aspects of these
processes are briefly reviewed below. They are discussed in
more detail in the proceeding section.
0 Sintering operations - This is the predominant
process of all four agglomeration processes used in the iron
and steel industry. As discussed in Section 2.4, sintering
can also be a source of potentially hazardous emissions.
The emission factor for the operation is 42 pounds of
particulate per ton of sinter produced. The industry is
experiencing difficulty in achieving emission reductions
near 100 percent.. At present, with only 90 percent emission
control, annual emissions are estimated to be 107,000 tons.
0 Coke ovens - By-product coke production is an in-
tegral part of major iron and steel plants. The coke ovens,
per se, are the major emission source from by-product coke
production. The gases emitted contain coal pyrolysis
products. Sulfur is present as hydrogen sulfide. A few
plants remove 70 to 90 percent of the H-S from coke oven
gas. An average of 12,000 cubic feet of gas is produced per
ton of ooal charged along with 10 gallons of tar, 3.5 gallons
24
of liquid oil and 19 pounds of light oil. In addition
fugitive dust is emitted from coal handling and transferring
operations.
2-40
-------
REFERENCES FOR CHAPTER 2
1. Reno, H.T. and F.E. Brantley. Iron, In: Minerals
Facts and Problems. U.S. Dept. of the Interior, 1970 Ed.
2. McGannon, H.E. The Making, Shaping and Treating of Steel.
Pittsburgh, Pennsylvania. U.S. Steel Company.
3. Kirk-Othmer. Encyclopedia of Chemical Technology, New York.
Wiley and Sons, Inc., 1966.
4. Lee, Oscar. Taconite Beneficiation Comes of Age at
Reserve's Babbitt Plant. Mining Engineering, May 1954.
5. Sisselman, Robert. Iron Ore in the U.S., A Profile of
Major Mining, Processing Facilities.
6. Miller, J.R. Impurities in Iron Ore, Columbus, Ohio.
Battelle Memorial Laboratories.
7. Labee, C.J. Steel Making Weirton Iron and Steel Engineer.
Oct. 1969.
8. Merrit, P.C. Mesabi Enters a New Era. Mining Engineering,
Oct. 1965.
9. At Reserve Mining Trial on Lake Fibers, emphasis shift
to economic impact. Engineering and Mining Journal.
March 1974.
10. Aiken, G.E., and others. Streamlining the North American
Taconite Industry, Society of Mining Engineering, October 1973
11. Vandergrift, A.E. and others. Particulate Air Pollution In
The United States. Journal of the Air Pollution Control
Association, Vol. 21, No. 6, June 1971.
12. Varga, J. Jr. and Lonnie, H.W. A Final Technological Report
on a Systems Analysis Study of the Integrated Iron and
Steel Industry, Battelle Memorial Institute, Columbus, Ohio.
13. Exhaust Gases from Combustion and Industrial Processes.
Engineering Science, Incorporated, October 2, 1971.
14. Lund, H.F. Industrial Pollution Control Handbook, New York,
McGraw Hill Book Company, 1971.
2-41
-------
15. Frame, C.P. and Elson, R.J. The Effects of Mechanical
Equipment on Controlling Air Pollution at No. 3 Sinter
Plant, Indiana Harbor Works, Inland Steel Company - Journal
of Air Pollution Control Association, December, 1963.
16. Benett, R.L., R.E. Hagen and M.V. Mielke. Nodulizing Iron
Ores and Concentrates at Extaca. Mining Engineering,
Jan. 1954.
17. Uys, J.M. and J.W. Kirkpatrick. The Beneficiation of Raw Materials
in the Steel Industry and Its Effect Upon Air Pollution Control.
Journal Air Pollution Control Association. January 1963.
18. Compilation of Air Pollutant Emission Factors. EPA Contract
No. CPA-22-69-119.
19. Jablin, Richard. Expanding Blast Furnace Slag Without
Air Pollution. Journal of Air Pollution Control Association.
Vol. 22, No. 3. March 1972.
20. Yard, E.M. and P.D. Nyajust. Open Hearths are Replaced by
Electric Furnaces. Iron and Steel Engineer, July 1967.
21. Haltgram, R., Fundamentals of Physical Metallurgy, Prentice
Hall, New York. 1952.
22. Wheeler, D.n T.4e Iron and Steel Industry Proceedings at
the Electrostatic Precipitator Symposium sponsored by APCA/
EAA. Feb. 23-25.
23. Parker, C.M. Basic Oxygen Furnace Air Cleaning Experiences.
Journal of the Air Pollution Control Association, Vol. 16,
No. 8, August 1966.
24. Proceedings of 24th Purdue Industrial Waste Conference,
1969.
25. Industrial Gas Cleaning Institute, Inc. Air Pollution
Control Technology and Costs in Nine Selected Areas.
Prepared for EPA, Sept. 1972, Contract No. 68-02-0301.
2-42
-------
3.0 FERROALLOY INDUSTRY SEGMENT
3.1 INDUSTRY BACKGROUND1
The main use of ferroalloys in the United States is in
the deoxidation, alloying and graphitization of steel. The
ferroalloys consist of iron in combination with one or more
other elements, including silicon, chromium, manganese, and
many other elements in lesser amounts.
The United States is the world's leading producer of
ferroalloys, production totalling 2.69 million short tons in
1971. Table C-l in Appendix C lists the tonnage of each
ferroalloy produced. Twenty-nine companies reported ferro-
alloy production in 1971; the individual plants are listed
in Table C-2, Appendix C. Plants •>'r rn±o and Pennsylvania
accounted for more than hali of the total tonnage. Pro-
duction was also reported from Alabama, Florida, Idaho,
Kentucky, Montana, New Jersey, New York, Oregon, South
Carolina, Tennessee, Texas, Virginia, Washington, and West
Virginia. Most ferroalloy plants are located in areas of
low-cost electricity, where shipping facilities are readily
available.
Major technological trends in the ferroalloy industry
during the past 5 years have been the use of larger fur-
naces, improved material handling procedures, and new tech-
3-1
-------
niques of solidifying molten alloys. A recent development
is the electroslag remelting process for steel refining.
The ferroalloy industry faces serious competition from
foreign producers who are capable of producing ferroalloys
at lower cost than domestic producers. Imports account for
about 40 percent of the domestic market.
3.2 RAW MATERIALS2
Manganese is the most widely used element in ferro-
alloys, followed by silicon, chromium, and phosphorous.
Others include molybdenum, tungsten, titanium, zirconium,
vanadium, niobium, boron, and columbium. Significant
quantities of limestone, coke, and alumina are used as
charge materials. About 75 pounds of carbon electrodes per
gross ton of ferromanganese are consumed in electric fur-
naces; this amount however, varies widely with raw materials
and with type ot ^rnace.
The United States imports almost all of the required
chromium and manganese ores from other countries. The
imported chromium ores contain about 45 to 53 percent
chromium oxide (Cr-O ); manganese ore contain 43 to 54
percent manganese. Silicon is an abundant commodity in the
U.S., significant deposits occuring in Washington, Oregon,
Montana, Idaho, California, Missouri, Illinois, Ohio,
Alabama, Tennessee, Kentucky, West Virginia, Pennsylvania,
and New York. Analysis of most of the available ores shows
95 percent or more Si02. Phosphorous in the elemental state
is not required for ferrophosphorous production, as it is
3-2
-------
recovered as a by-product of the thermal-reduction method of
obtaining elemental phosphorous from phosphate rock. The
Tennessee phosphorous industry is the main source of ferro-
phosphorous.
3.3 PRODUCTS
Various kinds and grades of ferroalloys are produced.
The main products, listed in Figure 3.1 are ferrophosphorous
(FeP), ferrochromium (FeCr), ferromanganese (FeMn), ferro-
silicon (FeSi)/ silicomanganese (SiMn), silvery iron (FeAg),
spiegeleisen (FeMn), ferroboron (FeB), ferrocolumbium (FeCb),
ferrotitanium (FeTi), ferrovanadium (FeV), ferronickel
(FeNi), ferromolybdenum (FeMo-), and ferrocolumbium-titanium
(FeCbTi). Pure manganese and silicon metals are also pro-
duced .
3.4 PROCESS DESCRIPTION
Figure 3.1 illustrates the ferroalloy segment. The
ores are beneficiated, reduced in one of three types of
furnaces, and cast. The processes and their emission
potentials are described in the following sections. Sub-
stantial fuel usage or other extraordinary energy require-
ments are identified.
3.4.1 Ore Handling and Beneficiation
(1*) Ore handling and beneficiation - The ores are used as received
from the mine or beneficiated, depending upon ore quality
and process requirements. Since most ores meet specific
* Numbers refer to corresponding processes in Figure 3.1.
3-3
-------
process requirements when purchased, beneficiation is
usually unnecessary.
The ore and other necessary raw materials are usually
transported to the plant by rail. The materials are stored
and subsequently sized and mixed to meet process require-
ments. Periods of rain or unusually cold weather may
necessitate drying of the ore. After mixing, blending, and
sizing are complete, the charge is weighed and subsequently
fed to a furnace.
All handling operations are potential sources of
fugitive dust emissions. Reported particulate emissions
from materials handling are approximately 10 pounds per ton
of alloy produced.
3.4.2 Smelting
Furnace operation in the smelting of ferroalloys con-
stitutes the major pollution problem. At present three
types of furnaces are used in ferroalloy production: the
electric furnace, the aluminothermic furnace, and the blast
furnace. Of the 48 ferroalloy-producing plants, three use
blast furnaces, five use aluminothermic furnaces, and the
rest use electric furnaces.
(2) Electric furnaces - The design and operation of all ferro-
alloy-producing electric furnaces are essentially the same.
The typical furnace is of the submerged-arc type. Raw ore,
a reducing agent, such as alumina, coal, and/or coke, and
slagging materials such as silica or gravel, are charged to
the furnace in appropriate quantities. The intense heat
3-4
-------
SMELTING
U)
I
flNISHIKC IKMTIHS
Figure 3.1. Ferroalloy production.
-------
zone (4000 to 5000°F) around the carbon electrodes is
responsible for the carbon reduction of the metallic oxides
present. The various impurities are trapped in the slag and
the molten ferroalloy is tapped from the bottom of the
furnace and cast.
The power required for the furnace ranges from 3000 to
^
3600 KWH, per ton, depending on the grade of ore and the
type and size of the furnace.
Emissions from electric furnaces vary widely, depending
upon the ferroalloy being produced, the type of furnace, and
the carbon content of the alloy. Large quantities of gases
are released during electric furnace operation. The gases
are produced as a result of carbon reduction, moisture in
the raw material, thermal decomposition of the raw ore,
vaporization of volatile components, and intermediate re-
actions releasing gases as products. The quantity of gas
generated is approximately proportional to the electrical
energy input; the exhaust rates for the common alloys are
presented in Table 3.1. Approximately 70 percent by volume
of the released gases is carbon monoxide. Other gaseous
components are volatilized metallics, sulfur oxides, cya-
nides, phenols, and oil. In an open electric furnace the
released gases are combusted and virtually all the carbon
monoxide, cyanides, and phenols are destroyed. In a covered
electric furnace, however, the offgases are not combusted;
. . 4
phenols and cyanides are emitted in significant quantities.
3-6
-------
Table 3.1 EXHAUST FLOW FROM ELECTRIC FURNACES
PROCESSING COMMON FERROALLOYS3
Product
Silicon Metal
50% Ferrosilicon
Standard Ferromanganese
Silicomanganese
Ferrochrome-Silicon
H. C. Fe rrochrome
Calcium Carbide
(SCFM/MW)
140-150
130-140
160-170
120-130
110-120
80-90
70-80
(Based on gas saturated at 100°F, scf at 30 in.
Hg, 60°F)
Particulates from electric furnaces are generally
oxides of the materials present in the ore. Table 3.2 gives
typical particulate emission rates for various types of
ferroalloys; Table 3.3 gives the characteristics of fumes
for various types of furnaces and alloys.
Table 3.2 PARTICULATE EMISSIONS FROM
FERROALLOY PRODUCTION
Source
B. Electric-Arc Furnaces
Quantity of Material
317,000 tons, f erromanganese
285,000 tons, silicomanganese
665,000 tons, ferrosilicon
96,000 tons, silicon metal
166,000 tons, silvery iron
590,000 tons, f errochrome ,
ferrophosphorus
Emission Factor*
44 Ib/ton
195 Ib/ton
357 Ib/ton
583 Ib/ton
120 Ib/ton
200 Ib/ton
* per ton of product.
When a wet scrubber is used to control furnace emis-
sions, the waste water may contain cyanides and phenols
scrubbed from the offgases. The waste water may also
3-7
-------
Table 3.3 TYPICAL CHARACTERIZATIONS OF FERROALLOY FURNACE FUMES'
I
CO
F'.;rnac» ; >• i ;<:t: 50* FeSi
Furnace Type Open
vuaie Siiape Spherical,
sometimes
in chains
Fume Size Char-
acteristics (u)
Maximum 0.75
Most Particles 0.05-0.3
X-Ray Dif fraction
Trace Con-
stituents FeSi
FeSi2
Chemical Analysis -
SiOo -:Z-3B
FeO
MgO
CaC
MnC
A12°~
L01
TCr as Crg03
SiC
ZrOg
PbO
Na20
BaO
KgO
C-MZ."
''pen
Spherical ,
sometimes
in chains
0.8
05 - ^ "*•
Fe, :4
Fe2J?
Quartz
SiC
61. IT;
14.08
1.08
1.01
C.12
2.10
--
--
1.82
1.26
--
--
--
— ~
Til-ln-* C.iMn** feMn ii.c.FeCr
Covered Covered jpen Covered
Spherical Spherical Spherical Spnerical
C. 75 J.75 S75 1 r'
0.--0.4 0.2-C.4 0.05-0.4 0.1-0.4
Mn^C^ Quartz t^n^C4 Spinel
MnC Sit-In Mn;, Quartz
Quartz Spinel Quartz
15.69 24.60 :C.46 2?.:'6
6.75 4.50 5.96 lJ.?2
1.12 3.78 1.03 15.41
1.58 2.24
31.35 31.92 33.60 2.64
5.55 4.48 6.36 7.12
23.25 12.04
29.27
--
--
0.47
2.12
__
— - — _ — — —
Chrorae jre- Mr. ;re**-
Li:r:e Melt Lime Melt
! pen 'pen
Spherical Spherical
anci irreg- and irreg-
ular ular
0.50 I.
0.05-0.2 0.
Q
2-0.5
Spinel CaO
10.65
7.48 1.
7.43 0.
15.06 34.
12.
4.SS 1.
13.86 11.
14.69
-.- _
0.
1.70 2.
1.
13.
28
22
96
24
34
36
92
_
_
_
98
05
13
08
* Si - G0-f,r4; Mn - 5-7$; Zr -
*-* Man,-ane.;c fame analyses in particular are salject to vide variations, depending on the
-------
contain dissolved solids, iron, zinc, aluminum, chlorides,
4
and copper. Disposal of the waste water can be a problem.
[3) Aluminothermic furnaces - The aluminothermic process for
preparing ferroalloys involves the co-reduction of iron
oxides and other metallic oxides by aluminum. The charge to
the furnace consists of raw ore, aluminum powder, iron scrap
or mill scale, a thermal booster such as sodium chlorate,
and a fluxing agent, usually lime or fluorspar. The re-
action may be initiated by two methods. One involves
ignition of the mix with an electrical arc from submerged
electrodes. The other method involves use of a small
quantity of a mixture of aluminum with barium peroxide to
ignite a priming batch, to which the charge is slowly added.
After initial ignition occurs, the reaction is highly
exothermic and the smelt is accomplished with no further
addition of energy. The temperature of the reaction is
controlled by adjusting the size of the charge particles and
the feed rate of the charge, or by replacing some of the
aluminum with a milder reductant, such as calcium carbide,
silicon, or carbon. The ferroalloy is tapped from the
bottom of the furnace and cast. Typical ferroalloys pro-
duced by this method include ferroboron, ferrochromium,
ferroniobium, ferromolybdenum, ferrotitanium, ferrotungsten,
and ferrovanadium.
As with electric furnaces, emissions from aluminothermic
furnaces vary widely in type and quantity, depending upon
the ferroalloy and the physical characteristics of the
3-9
-------
charge. Large amounts of gases are released, consisting of
volatile metallies, water vapor, carbon monoxide, and other
gases absorbed in the charge materials. Particulate emis-
sions are substantial because of the fineness of the charged
materials and the violence of the reaction. The composition
of the particulates emitted varies widely with different ore
compositions; emissions consist primarily of oxides of the
different charging materials.
Water pollution problems arise only with the use of wet
scrubbers. The scrubber waste water may contain cyanides,
phenols, dissolved solids, iron, aluminum, zinc, chlorides,
and copper.
4) Blast furnaces - Blast furnaces are of minor importance in
the production of ferroalloys. At present only three are in
operation in the United States. Two produce ferromanganese
and the other i_i*"""!v.-jes silvery iron.
The charge consists of raw ore, iron ore, coke, and
limestone. The furnace is fired with fuel oil or natural
gas, and usually operated at around 1430°C, just above the
slag formation temperature of 1426°C. The ores undergo
carbon reduction and the ferroalloy sinks to the bottom of
the furnace, where it is tapped and cast. Temperature of
the exit gases is usually between 700 and 900°F.
Since the basis of operation of the blast furnace is
carbon ^-Juction, the major constituent of the gases emitted
is carbon monoxide. Other gaseous components are volatilized
3-10
-------
metallics, sulfur oxides, and various organics. Most of the
combustible gases, especially CO, are burned before being
emitted to the atmosphere.
The escaping gases may carry large quantities of dense
smoke, created by the disintegration of coke and ore and by
vaporization and condensation of various materials. About
410 pounds of particulates are emitted per ton of ferroalloy
produced. Approximately 20 percent of the particulates
emitted consist of particles larger than 20 microns. The
remaining 80 percent consist of particles in the range of
0.1 to 1.0 micron.
Blast furnace operation entails no significant water or
solid waste problems.
3.4.3 Slag Processing
(5) Slag processing - The slag is treated by two methods: con-
centration and shotting. In the concentration process, the
slag is dumped in water, where metal particles sink to the
bottom and are recovered while the slag floats and is re-
moved. The recovered metals and other wastes from the
shipping department are recycled to the furnace charge; as
high as 30 percent of the charge may be recycled material.
The concentration process is generally used on ferrochromium
slags. The shotting method, which involves the granulation
of molten slag in water, may be used on ferromanganese
slags. The main problem in slag processing is water pollution
in the form of suspended solids and dissolved metallics,
3-11
-------
such as manganese and chromium. The waste water may also
contain a small amount of oil.
3.4.4 Finishing Operations
( 6 ) Casting - Hot metal from the furnace is usually cast in
ingot form in various types of molds depending on the ferro-
alloy produced. Several kinds of mold coatings and toppings
are used. After sufficient cooling and solidification, the
casts are removed from the molds, graded, and placed in hot
metal skip boxes, where the alloy is held for further
processing. The casts are processed by hand breaking or by
use of pneumatic breakers, depending on the ease with which
they can be broken. At some plants the ferroalloy casts are
washed free of disintegrated slag (prior to breaking) to
insure cleanliness.
( 7 ) Sizing - The broken material from the casts is passed through
a crusher and screen to produce materials of uniform size.
Cranes are used for feeding the crushers. If two crushers
are used, material from the primary crusher is transferred
to the secondary crusher by belt conveyors.
The crushing and screening operations result in par-
ticulate emissions that may be easily controlled.
^ ( e ) Packing and shipping - The crushed and screened material is
shipped in bulk form or is packaged in containers. The
crushing, screening, grading, and packing are mostly ac-
complished in the same unit to minimize handling of materials.
If direct packing cannot be accomplished, the sized materials
are stored by grade in metal tote boxes, skips, or bulk
3-12
-------
floor bins. The package is weighed, inspected, topped off,
covered, and stenciled, then placed in temporary storage or
loaded directly for shipment by truck or rail.
These packing and shipping operations also cause small
quantities of particulate emissions.
3.5 MAJOR POLLUTANT SOURCES
Smelting is the major source of pollutants in the
ferroalloy industry. Of the three types of furnaces in
operation, the blast furnace is least important, since only
three blast furnaces are in operation. Not much information
is available on the aluminothermic furnace, but it is
assumed that the pollution will be similar to that from
electric furnaces.
0 Electric furnaces - The emissions from the furnace
vary widely in type and quantity depending upon the par-
ticular ferroalloy being produced, type of furnace used and
the carbon content of the alloy. Approximately 70 percent
of the gas released is carbon monoxide. Other gas com-
ponents are volatilized metallics, sulfur oxides, cyanides,
and phenols. The phenols and cyanides are absorbed into the
scrubber water and precautions are necessary. Because of
the nature of the raw materials introduced, the gases re-
leased are mostly toxic.
The emission factor for electric furnaces is 240 pounds
of particulate per ton of ferroalloy. In 1968 the net
control achieved for controlling particulate emissions from
electric furnaces in the United States was less than 50
percent.
3-13
-------
REFERENCES FOR CHAPTER 3
1. Fisher, F. L. , Ferroalloys, In: Minerals Year Book.
U.S. Bureau of Mines. 1971.
2. McGannon, H.E. The Making, Shaping and Treating of
Steel.
3. Vandegrift, Dr. A.E., et al. Particulate Pollutant
System Study. Volume III - Handbook of Emission
Properties, E.P.A., Contract No. CPA22-69-104, May
1971.
4. U.S. Environmental Protection Agency. Ferroalloy
Manufacturing Point Source Category. In: Federal
Register, Environmental Protection Agency, Washington,
D.C. Vol. 38, No. 201 (Part II).
5. Kirk-Othmer. Encyclopedia of Chemical Technology, New
York, John Wiley & Sons, Inc., 1966.
6. Fields, J. Processing and Handling of Ferroalloys.
Journal ^f T^cals. 357-360, March 1966.
7. Leeper, R.A. and T.J. Dyerdek. Smelting of High Carbon
Ferrochromium in a Three Phase Electric Furnace.
Journal of Metals. 353-356, March 1966.
8. Sansom, R.L. Development Document for Proposed Ef-
fluent Limitations, Guidelines and New Source Per-
formance Standards for the Smelter and Slag Processing
Segment of the Ferroalloy Manufacturing Point Source
Category. Environmental Protection Agency, Contract
No. 440/1-73/008, August 1973.
3-14
-------
4.0 COPPER INDUSTRY
4.1 INDUSTRY BACKGROUND1
The United States is the world's leading copper producer.
Domestic mine production in 1971 was 1.52 million (copper content)
short tons. In addition to this, approximately 181,000 short
tons of copper was imported, and 187,700 short tons of refined
copper was exported. The electrical equipment industry is the
major U.S. consumer of copper, accounting for approximately
half of the total domestic consumption; other major users are
construction operations (16 percent), industrial machinery (12
percent) , transportation (8 percent), and ordnance (6 percent).
Domestic demand for primary refined copper in the year 2000
2
is estimated to be 4.9 to 7.86 million short tons; by compari-
son, the 1971 consumption was 1.59 million short tons of refined
copper.
Ninety percent of the United States copper is mined in
five western states - Arizona, Montana, Nevada, New Mexico,
and Utah. The remainder is obtained from Idaho, Michigan and
Tennessee. Some large United States copper producers are also
operating in Canada, Mexico, Chile, Peru, the Republic of South
Africa, and Zambia.
The major copper companies operate mining, smelting, refining,
4-1
-------
and fabricating facilities, and also operate their own marketing
organizations. Smaller companies mine and concentrate the
ore and ship the product to major companies or to companies
having only smelting and refining facilities. In 1968, approxi-
mately 45 percent of the ore was produced by five leading mines
and approximately 85 percent of the Nation's total smelting
capacity was controlled by four companies. Most of the ore
is treated in concentrators near the mines. In 1971, there
were 19 U.S. smelters: eight in Arizona, three in Michigan,
and one each in Utah, Montana, Nevada, New Mexico, Tennessee,
Texas, New Jersey, and Washington.
Table D-l of Appendix D provides pertinent statistics on
copper mining operations.
Recently Outokumpu Oy of Finland developed a "flash smelting"
process which provides an atmosphere surrounding the copper
smelter totaix^ free of sulfur dioxide emissions. The Lummus
Company of New Jersey is providing the design, engineering
and construction for plants utilizing the process.
4.2 RAW MATERIALS
Many copper-bearing minerals are widely distributed throughout
the various ore deposits. Table 4.1 lists the major types
of ore and the minerals found in each ore.
Of all these copper-bearing ores, only chalcocite, chalco-
pyrite, bornite, chrysocolla, azurite, and malachite are commer-
ci-..i.ly important. Copper ores occur in many types of deposits
in various rocks. About 90 percent of the U.S. copper ore
4-2
-------
Table 4.1 MAJOR COPPER-BEARING ORES"
Type of ore
Mineralogical name
Form of copper
Sulfide:
Oxide:
Bornite
Chalcopyrite
Enargite
Tetrahedrite
Tennantite
Calcocite
Covellite
Complex famatinite
Bournonite
Cuprite
Tenorite
Malachite
Azurite
Amtlerite
Brochantite
Atacamite
Chrysocolla
CuFeS
(As,Sb)S4
CU12AS4S13
Cu2S
CuS
(Sb,As)S4
PbCuSbS
CU20
CuO
CuC03Cu(OH)2
2CuCO Cu(OH)2
CU4S04(OH)6
CuSiO3:2H20
4-3
-------
occurs in porphyry copper deposits.
Though different copper ores have different compositions,
they contain many of the same elements. Table 4.2 gives a
typical analysis of copper ore.
4.3 PRODUCTS
Ninety-eight percent of the copper is produced from ores
mined primarily for copper; the remainder is produced from
ores mined principally for other metals. In addition to copper,
significant quantities of gold, silver, molybdenum, nickel,
selenium, tellurium, arsenic, rhenium, iron, lead, zinc, sulfur,
and platinum-group metals are recovered as by-products. Table
4.3 shows the coproduct and by-product relationships of copper
with other metals.
4.4 PROCESS DESCRIPTION
Figure 4.1 illustrates the copper industry segment. The
operations are aixning, concentration, smelting and electrowinning,
electrolytic refining, and fabrication.
The ores are smelted down either as they come from the
mine or after they are subjected to a refining process of grind-
ing and flotation, which transforms low-percentage-copper ore
into high-percentage-copper concentrate. In some cases, the
concentrate is partially roasted before smelting to remove
part of the sulfur and produce a favorable balance of copper,
iron, and sulfur for feed to the reverberatory furnaces. In
the ..everberatory furnace, iron oxide combines with a siliceous
flux to form a slag, leaving a material known as matte, which
4-4
-------
Table 4.2 TYPICAL ANALYSIS OF COPPER ORE
USED AT WHITE PINE COPPER COMPANY, MICHIGAN4
Element
Cu
Ag
Au
A1203
SiO2
CaO
Fe
MgO
Ni
S
Pb
As
Mo
Bi
Mn
Zn
Na
K
Co
Se
Percentage
1.0
0.25 oz./ton
Trace
15.0
61.5
7.4
6.6
3.7
0.005
0.35
0.001
0.0005
0.002
0.0001
0.05
0.001
1.5
1.0
0.003
0.0005
4-5
-------
Table 4.3 COPRODUCT AND BY-PRODUCT RELATIONSHIPS
OF COPPER WITH OTHER METALS
Source
Copper
Do
Do
Do
Do
Do
Do
!>,>
Do
Do
Do
Do
Do .
Do
Lead
7;liC
>ii ^
Tungsten
Gold
L'ranium
Product
Arsenic
Rhenium
Selenium
Tellurium
I'l.ittnum
Sih.r
Cold
Molvbdenum
Nickel
Sulfur
7inc
Iron
Lead
Copper
do . .
do . ..
do . .
do . .
do
do
do
Unit
1,000 short tons
I'our.ds
1,000 pounds
do
1. 000 ounces
do
do
1. 000 pounds
do
1,000 long tons
1 ,000 short ions
do .
Short tons
1 000 short tons
. do
do
. . do
do
. . do
do .
Short ions
Quantity
S
2,400
VV
w
5
9.551
406
23.777
4.060
529
9
379
48
1.182
8
5
W
3
W
W
W
Total
output,
percent
100.0
100.0
100.0
W
45.9
29.2
27.5
25.5
13.4
5.4
1.8
.7
98.1
.7
.4
W
.2
W
W
W
W Withheld to avoid disclosing individual company confidential
data.
4-6
-------
contains copper, iron, and. some sulfur. The matte is reduced
to copper in a converter. This crude copper, called blister
copper, undergoes further purification by fire refining to
reduce the sulfur and oxygen contents. The refined blister
copper may then be cast into anodes for electrolytic refining.
These processes and the emissions they produce are further
described in the following sections. Extraordinary energy
requirements are also noted.
4.4.1 Mining and Concentration
(1*) Mining - Open-pit and underground methods are used in mining
various types of copper deposits. Open-pit mining accounts
for nearly 85 percent of the copper ore mined in the United
States. The basic operations are drilling, blasting, loading,
and hauling.
Large amounts of fugitive dust are evolved from the mining
of ore. In 1968, about 490 million tons of waste material
was discarded in the mining of 170 million tons of copper.
The dust consists of all the materials present in the ore.
The copper content of the discarded sulfide ore material varies
from zero to the copper content of the ore grade. Water pollu-
tion is not a problem, since open-pit mining is a dry operation.
Vast areas of land are used for disposal of copper mining
tailings. Typically the copper mine tailings contain no organic
matter and no nitrogen. Tailings and their constituents are
discussed more fully in the following section concerning concen-
tration (2) .
* Numbers refer to corresponding processes in Figure 4.1.
4-7
-------
The ore is loaded into rail cars or trucks by electric
shovels. It is transported to concentrators by standard gauge
railroads, trucks, skipways, and conveyor belts. Rail haulage,
hoisting facilities, and shuttle cars are used in large under-
ground mines.
Several copper deposits are now being worked by in-place
leaching. The deposits are first cut by a system of tunnels,
fractured by explosive or hydraulic methods, then leached by
sulfuric acid introduced through pipes to the upper part of
the deposit. The copper-rich fluids are withdrawn from the
lowest levels of mine workings and pumped to the surface, where
the copper is removed electrolytically or by cementation.
The main disadvantages of the method are that only 50 to 60
percent of the copper in the ore deposit can be recovered by
present techniques and the more valuable by-products, i.e.
gold and rhenxuia, are left in the rock during the leaching
process.
Depending upon the sub-strata, mining operations may have
significant potential for ground water contamination. Also,
some particulate emissions are often associated with development
of the mining site.
(2) Concentration - Copper ores are upgraded from less than 1 percent
copper to approximately 15 to 30 percent copper content. Although
the concentrating methods vary according to the physical proper-
ties, ot the ore, concentration generally involves crushing,
grinding, classification, flotation, and dewatering. The collec-
4-8
-------
SMUTIKC
*»
I
o
_.J .
EUCTIQUTIC
Figure 4.1. Copper industry.
-------
tors (additives) used in flotation are determined by the other
minerals present in the copper ore; they may be xanthates,
dithiophosphates, or xanthate derivatives. Flotation is usually
used only for sulfide ore; recently, however Earth Resources
Company has reported good results from concentration of low-
grade copper oxide by the flotation method. Oxide ore,'-: are
treated by hydrometallurgical methods by leaching and cementation
Rod-mill grinding is common. Lime and wacer are added during
grinding to condition the mineral. Table 4.4 lists elements
that may be present in copper concentrate.
Approximately 2 pounds of particulate per ton of ore pro-
cessed is emitted from concentrating plants. Since much of
the water used is recycled within the process, water pollution
problems are minimal.
Tailings f--,-"- * milling operation and the tailings and
overburden from the mine are dumped at the nine site. Copper
mine tailings are mildly alkaline. The minor elements in
mine wastes are present in low concentrations and create no
air or water pollution problems.
The following tables illustrate typical composition of
copper mine tailings and acid-extractable tailings' metals.
For internal operations within a concentration plant, oie
-irs and conveyors are used to transport materials. The concen-
trate is transported by conveyors, railroads, and trucks to
the smelters, and is stored with fluxes to be charged to the
smelter.
4-10
-------
Table 4.4 ANALYSIS OF COPPER CONCENTRATE
Element
Cu
Pb
Zn
Ag
Au
Pt etc.
As
Sb
Bi
Se
Te
Ni
Co
Cd
In
Tl
Ge
Sn
Cl
F
S
Fe
Al
Si
Ca
Mg
Mo
Mn
Composition
20-50%
11%
9%
40 oz.
1 oz .
tr.
0.25%
0.15%
0.02%
0.02%
0.01%
0.05%
0.02%
0.01%
tr.
tr.
tr.
tr.
0.05%
0.05%
N.A.
N.A.
N.A.
N.A.
N.A.
N.A.
N.A.
N.A.
N.A. = not applicable
4-11
-------
Table 4.5 COMPARATIVE ANALYSES OF TAILINGS, UNDISTURBED
DESERT, AND OVERBURDEN AREAS, PIMA MINING CO., 1972
.--V.--.T.-.
Soil
ma.,.,,al
Ta.lmq
Taili'U) ami
nvp'bmdpn
OverUmlun
DpseM
r v (%i
Siqtiifip.incP
1 BPIWPPII
2 Hi'tiM'i'li
Lpi)pi"1 os
Mp;*ns fo
SKtnilu-anrp
Dpplh
of
Siinipip
1. p.)
15
91
15
91
15
91
15
91
ol eliHnti
snii.lppt
Mil! lll.'ltl
l)l)t Sll
low/eft t)y
(Sllllti-m
Orqanu
maflpT
<"">
021 .1
0 18 a
Ollh
0 11 li
OHb
0 14 b
0 IB .)
0131)
26
iirps
li.lls ' '
nth. ant at
Ilin sarn.'
Npwman
Bulk
dpnsity
(q mi '
1 .IS I)
1311)
1 3-t 1)
1 40 a
1 2" 1)
1 28 1)
1 3 7 h
1 27 li
4
MS
5"'.. '
Ipllpl V
Ki-ul (.»
A
»H
7 75 a
7 B8 .1
7 78 a
7 55 t)
7 85 a
7 SIS li
7 45 li
7 44 1)
1'J
su|t)ihi
vilhin so
li
Total
solublp.
salts
(PI"")
355 P
2 .' 1 i-
28f,n h
2808 h
2452 h
?8'lti t.
3182 a
5540 a
73
* '
,1111 ,11 5%
1 ilopths
_-T._- '. • -- -
NO ( N P
22 n 311.
7 a 48 a
7 li 261)
8 a 1 li
7 h 2 1)
H a 2 h
6I> 1I>
3 h 1 1)
b7 5!)
ns
'• SKl.nli.ant
an: nol rtiffpfpnf
IS ipfMTl)
N.I K
or, i. si .1
55 li 35 a
IHn.i 25t)
104,1 31,1
135 a 15 h
107 a 20 h
63 ti 1 7 h
55 h 211)
47 43
IIS
at Pi,
ill Ihf! 5"n lOVP] Of
- -•-... organic m;iltot. hulk density. pH. total soluble salts NO3 N.
idotablo Na. and extractahle K in soil materials in tailing berms
.i,. .... -ng Co. 1972
s
M.il
Tnilinc
T nlmq
ovrrbi
Ovnb
Oosfrt
cv i-
Siqmfi
1 DP
2 BP
t rupn
V,,'
Si'JIllf'
[>tith
ful S II!)])''
enal (cm)
15
91
a»,l 15
idrn 91
irden 1 5
91
15
91
,i
i an' P of riiffprp
fp
16215 rf
141,78 ;i
13O13 t>
1 1 188b
Gt l J (t
5R?8r
7255 c
4G83 rJ
43
nrl-S
Am
Mil
7O2B a
37SR i-.
(SOtr, i,
352Oi:
3131 (I
23 t)
67 i.
54 li
64 i
40 i
55
.:.-- . -
Mn
ippn
1 78 .1
!)4 ti
1 Ifi ,ib
54 li
MS b
72 1)
t 7H .)
159 a
43
Cu
I*
7(i1 -l
7(19 j
(>B'3 t)
521 h
22 i;
9 '.
Hi r
13 c
!)9
Fp
823
HI21
(, I'l
SOS
IS
12
21
18
103
Availabin
Mi]
,1 7 1 B 1)
a 832 ,i
li OBG 1-
h 541 b
r 438 i:
c: 371 c
p 33H r
r. 354 c
33
Cu
30 it
firi a
25 h
24 b
4 '.:
2 <
3 <
2 c
1O9
WCPP sot! ilppttis
wpf*n st>tl niati
afis to'icAPil by
ram i1 'Stiuli-Mi
rials
l\« ,. :• ;-l
lMlll-1 W
Kc.ii I"'.'
n,m s,
p nol f
t at the 5
Ipvrt ot
g _ Average acui cxtractiihlu f^e. Mi) 7n Mn and Cu and available Fi>. Mg
and Cu at two depths in soit materials in tailiny berms Ptma Mining Co . 1972
4-12
-------
(3) Hydrometallurgy (Leaching and Cementation) - Valuable metals
are separated from gangue by lixiviation. This method is usually
used with oxidized, mixed oxidized and sulfide ores, and native
coppers. The most commonly used solvent is 5 to 10 percent
sulfuric acid. Ferric sulfate or ammonia solutions are also
used, the latter on native copper ores of Michigan. Leaching
methods include leaching in place, heap leaching, percolation
leaching, and agitation leaching.
The treatment of mixed ore, containing both sulfide and
oxide minerals/ depends upon the relative proportions of the
two types of minerals. Ores that contain equal amounts of
sulfide and oxide are treated by a method combining leaching
and flotation.
Increasing amounts of copper (cement copper) are produced
by precipitation of copper from mine waters and leach solutions
with scrap iron.
No particulate is emitted from leaching operations, but
considerable water pollution is associated with this process.
4.4.2 Smelting
Smelting includes roasting, reverberatory smelting, convert-
ing, and fire refining.
W Roasting - Although roasting is not used in the majority of
plants, it is still practiced by some operations, who use multiple-
hearth roasters and fluid bed roasters, which operate autogenously
Their offgases contain up to about 15 percent SO~.
£m
a) The sulfuric acid used is normally produced as a by-product
from smelter flue gases.
4-13
-------
The main purpose of roasting is desulfurization. Usually
the concentrates have high sulfur content. Much of this sulfur
is useless and creates air pollution problems as SO2 in sub-
sequent operations. The roasting not only eliminates much
of the sulfur from the concentrate, but makes it possible to
economically recover it as H2S04. The disadvantage of roastirio
is an increase in the amount of copper lost in t;.e slag.
The concentrated ore contains S, Fe, Si, Ca, Al, Mg, Zn,
Cd, Mn, Co, Ni, As, Sb, Bi, Pb, Se, Tl, Te, Au, Ag, Pt, and
Pd. It is heated in the presence of air with the addition
of fluxes, and the sulfur in the ore is oxidized and partially
eliminated to produce a "roast" with suitable composition for
further smelting.
The temperature of the roast ranges from 400°F at the lowest
hearth levels :" ' ernal heat is provided by gas or oil firing.
The roaster o^oduct "calcine" is passed to reverberatory furnaces
Effluent gases from the roasters contain SO2, which may
be used as a feed to a sulfuric acid plant. The collected
fumes from the roaster are heated to separate a residue contain-
ing Pb and Sb from crude material containing As2C>3. The residue
is transferred to a lead smelting unit. Table 4.6 gives typical
input and output data for a roaster. Table 4.7 identifies
tl-'o major elements in the feed to a typical copper roaster
and the disposition of these elements.
The roasting operation generates about 170 pounds of partica-
late per ton of copper. Total annual particulate emissions
in the U.S. from all roasting processes is estimated to be
4-14
-------
Table 4.6 TYPICAL INPUT AND OUTPUT TO A
p
COPPER ROASTER (TONS PER DAY)
Cu
Fe
S
SiO
CaO
Other
H2°
Air
S02
N2
Charge
concentrate
200
300
350
100
80
100
830
Flux
90
35
40
Calcine
200
300
175
190
35
120
Roaster
gas
100
350
655
Table 4.7 DISTRIBUTION OF ELEMENTS IN FEED
TO A COPPER ROASTER
.
Element
Cu
As
Sb
Bi
Pb
Zn
Cd
Se
Te
Charge
composition /
25
0.25
0.15
0.02
11
1
0.01
0.02
0.01
Amount
into
roasted
product /
99
20-50
40-60
60-80
25-50
60-75
60-75
50-75
75-90
Amount
into dust
collector
catch /*
-
50-80
40-60
20-40
50-75
25-40
25-40
25-50
10-25
Unaccounted,
%
-
0-1
0-1
0-1
0-1
0-1
0-1
0-5
0-2
*Note: Collected fume circulates or goes to arsenic recovery
4-15
-------
7000 tons. The volumetric flow rate of exhaust gases varies
considerably with plant capacity and design.
The composition of the particulates is dependent on the
ore type. Common constituents are arsenic, antimony, mercury
and lead, which except for mercury appear as oxides in the roaster
effluent. The uncontrolled emission rate for S02 from the roaster-
is 60 pounds per ton of copper produced. An SO^ reduction in
excess of 90 percent can be obtained by using a combination
of sulfuric acid plants and lime slurry scrubbing. About
1 to 3 percent of the S02 is converted to S03. The SO3 may
combine with water vapor at temperatures below 400°F to form
sulfuric acid mist.
Table 4.8 lists the contaminants of the gas stream from
a typical roaster.
Table 4,o CONTAMINANTS OF GAS STREAM FROM ROASTER
11
Chlorides as Cl
Fluorides as F
Arsenic as As-O.,
Lead as Pb
Mercury as Hg
Selenium as Se
Total Solids
S02 content, vol . %
of oxygen
Solid content,
grams
0.055
0.011
0.087
0.087
0.0011
0.044
0.44
7
gr/DSCF
0.071
0.014
0.11
0.11
0.014
0.056
0.56
9
4-16
-------
Volumetric flow rate of exhaust gases vary considerably with
plant capacity. A typical gas flow rate is 16,000 SCFM, The
furnace gases are cooled by dilution air. Average temperature
12
of the gases is approximately 1200°F.
(5) Reverberatory smelting - The roast charge or the wet concentrate
(if roasting is not practiced) and limestone flux are transported
from bins by a conveyor belt system and fed to the reverberatory
furnace through a hopper. This process produces a slag and
copper matte containing 15 to 50 percent copper. The liquid
matte is formed at about 1800°F.13 Table 4.9 lists the approxi-
mate distribution of elements into the matte, slag, and fume.
About three fourths of the U.S. plants use natural gas
to provide the required heat input; most of the remainder use
pulverized coal.
Table 4.9 DISTRIBUTION OF ELEMENTS IN
REVERBERATORY FURNACE FEED
Element
Cu
As
Sb
Bi
Pb
Zn
Cd
Se
Te
Charge
composition,
15-50
0.13
0.09
0.02
5
0.75
0-01
0.02
0.01
Amount
into
matte,
%
99.0
80-90
85-90
90-95
75-90
10-25
5-15
95-100
95-100
Amount
into
slag,
%
N.A.
10-20
10-15
5-10
10-25
75-90
65-80
0-5
0-5
Amount
into dust
collector
catch,*
N.A.
0-10
0-6
0-1
0-10
0-25
0-25
nil
nil
4-17
-------
If a particulate control device is used on the reverberators
furnace, the flue dust is usually circulated back to the charge.
The slag is usually sent to a waste dump; it contains Fe , Ca,
Si, Al, Mg, Mn, Co, Zn, Sb, Cu, Ag, and Pb .
About 206 pounds of particulate is emitted per ton of copper-
In 1969, annual particulate emissions from this process in the
U.S. totaled 28,000 tons.9 Significant quantities of potentially
hazardous materials, as identified in Table 4.9, may be emitted
if suitable emission control devices are not used. Furnace
gases contain 1 to 2 percent S02 and 13 percent CC>2 . The volu-
metric flow rate of the exit gases averages 50,000 SCFM, and
the temperature is 700 °F.7 Table 4.10 presents typical composi-
tions of the exit gases from reverberatory furnaces. Because
of the low SO2 concentration found, it is not economical to
make H2SO4 from
oratory gases
Table 4.10 COMPOSITION OF REVERBERATORY FURNACE EXHAUST GASES
°2
N2
CO2
H^O
CO
so2
Volume %
Minimum
5
72
10
4
0
1
Maximum
6
76
17
10
0.2
2
irters - The ir.olt'~*> matte from the reverberatory smelter
cnarged to the converter. Recycled material from zinc plants
4-18
-------
soda-ash, recycled dust, scrap, siliceous ore, and flue dusts
are also added. A charge consists of 163 tons of 35 to 40 percent
copper matte, 40 to 50 tons siliceous flux, and 40 to 50 tons
of cold copper-bearing material, such as scrap and matte.
Air is forced through tuyeres into the molten matte to produce
blister copper. Most of the iron present in the matte is oxidized
and slagged with silica flux, which is then recycled to the
reverberatory furnace. Converter temperatures are maintained
at approximately 2200°F. Table 4.11 identifies the elements
found in the charge to the converter. The converter requires no
external source of heat; requirements are satisfied by heat of
reaction in the converter.
Table 4.11 DISTRIBUTION OF ELEMENTS IN CHARGE
TO THE CONVERTER
Element
Cu
As
Sb
Bi
Pb
Zn
Cd
Se
Te
Charge
composition,
40
0.2
0.12
0.03
4.5
0.3
0.01
0.04
0.02
Input
into
blister,
Bulk
40-60
50-70
70-80
5-10
nil
nil
90-100
90-100
Input
into dust
composition,
catch, %
—
40-60
30-50
20-30
90-95
90-100
90-100
0-10
0-10
Input
unaccounted
—
0-10
0-10
0-10
0-10
0-10
0-10
nil
nil
4-19
-------
The effluent gases are rich in sulfur dioxide and may be sent
to a sulfuric acid plant for recovery. The exhaust streams
contain lead, antimony, arsenic, bismuth, selenium, tellurium,
zinc, cadmium, and thallium. The collected dust is shipped
to a lead smelter for recovery of lead, antimony, bismuth, and
thallium. Significant quantities of hazardous materials can
be emitted if high efficiency particulate control devices are
not used.
The converters emit about 240 pounds of particulate per
ton of copper produced; annual particulate emissions from the
process in the U.S. total 32,000 tons.
Since the slag is recycled to the reverberatory furnace,
no solid or liquid wastes are generated.
The gases are emitted at a rate of 16,000 SCFM.
The moltr>- -.'.:•• a is brought in ladles from reverberatory
furnaces by a crane and charged to the converter through a hood.
The flux is stored in a bin, from which it is conveyed to the
converter.
The blister copper is moved for refining by short haul
methods, such as rail or crane and ladle when the refinery is
very near or an integral part of the smelters.
(7) Fire-refining furnace - Blister copper from the converters is
fire-refined to remove impurities and to adjust the sulfur and
oxygen contents to levels suitable for casting. Furnaces in
common use are of the reverberatory or the tilting cylindrical
type. The fire-refined copper may be cast into anodes for elec-
4-20
-------
trolytic purification; demand for electrolytically refined copper
is increasing at the expense of demand for fire-refined copper.
About 5 percent of the world's copper is supplied as fire-refined
copper.
The fire-refining process consists of melting, blowing
and poling. The blister is first melted by a hot air stream
prior to blowing. Fluxes are then added. During this process
sulfur and volatile impurities are evolved as oxidation takes
place. In addition, the volatile metals such as cadmium and
zinc are removed into slag during blowing. Oxides of iron, arsenic,
lead, copper, and other substances are skimmed as slag and sent
back to copper smelters. The oxygen content is reduced by forcing
wood logs below the molten metal surface (poling). Table 4.12
lists the disposition of elements in the feed to the refining
furnace. Particulate emissions are minimal.
The molten copper is transferred to the furnace from the
converter by ladle.
Table 4.12 DISPOSITION OF ELEMENTS IN
FEED TO REFINING FURNACE
Element
Cu
As
Sb
Bi
Pb
Zn
Cd
Se
Te
Charge
composition,
98
0.06
0.03
0.04
0.5
nil
nil
0.1
0.05
Input
into
refined,
copper
99.6
nil
nil
nil
nil
nil
nil
nil
nil
Input
into
refined,
products
_
nil
nil
nil
nil
nil
nil
85-95
90-100
Input
into
slag,
-
90-100
90-100
90-100
90-100
90-100
90-100
5-15
0-10
Amount
unaccounted,
-
0-10
0-10
0-10
0-10
nil
nil
0-15
0-10
4-21
-------
(8 ) Casting - The casting operation for fire-refined copper is compar-
able to that for electrolytic copper. The casting of anodes
from an anode furnace is performed on a casting wheel. Copper
is poured from a furnace into a ladle. The mold temperature
is regulated by water sprays. The cast anodes are cooled and
then sent to the electrolytic refinery. Casting the copper
may cause some air pollution.
4.4.3 Electrolytic Refining
(9 ) Electrolytic cell - In the electrolytic cell, the copper from
the impure anode is dissolved electrolytically and migrates
to the cathode, where it is deposited. The impurities in the
anode copper either dissolve in the electrolyte, which is a
solution containing copper sulfate and sulfuric acid, or fall
into the slime.
Electrolytic cells require approximately 200 KWH per ton
of cathodes i ^a. Natural gas or fuel oil is also required
to fire the melting furnace used to produce anodes.
Table 4.13 presents a typical analysis of the anodes, electro-
lyte, refined copper, and slime.
Table 4.13 GENERAL RANGE ANAYLSIS OF ANODE,
ELECTROLYTE, REFINED COPPER, AND ANODE SLIME
Con*
Slllfl]
Hllllll
" ''M'l
.'llltil
liisin
iluent
],' ,',rid
•r
•n
•
ie
11,11V
ilh
lend
nickel
.•selenium
tellurium
H"l
0
0
0
0
0
II
-0
0
0
3
, l-;ie.-lr..l\le, K..l
170 -j::n
Ii l.'l .",11
1)1
2 0 :, U
1 o '_' n 7
(II Old",
•J
2 • II _,l II
(111
Ol!
()'•
'.10''
liefined c
ii n:;
ii mil
II OOOl
II (UK I'J
O IIIIOOI
II HOI 11!
n 0001
n IH in.;
O. 1 101 II
O.Oirj
O.O.'i
'!'
II
0
0
1)
0
II
o
o
0
0
0
M-r, ' ,
D.'i
1 K I'J
IHII
Dill
1 II II I'J
III 1 1 0
1 II I'J
out
HI III' 1
Hi''
• f
(.ll
II
0
-
II
1
o
s
y
'-'
. )
••
(1
1
.(»
•;>
,O
1000
lime, ' r
1.MS1S)
10
r,
1 ll
:,.o
15 (l
2 0
20 I)
-S (1
.{Oil'1
Midi)''
1 Kxtrouics oiniU<"(l.
^Tmy ounces (:n.!03g) por tun (2000 Ih).
4-22
-------
Atmospheric emissions from the cells should be relatively
minor, although trace amounts of some elements may be emitted.
Proper operation of the cell should cause little pollution,
since the cell slime is sent to the precious-metal recovery
plant and the spent electrolyte is sent to the electrolyte purifi-
cation plant.
(10) Electrolyte purification - The electrolyte is purified by elec-
trolysis to control the concentrations of copper and soluble
impurities. Copper from the solution is deposited on the cathode
and the electrolyte solution (containing sulfates of As, Sb,
Bi, Ni, and Cu) is transferred to open or direct-fired evaporators,
where it is further concentrated to produce nickel sulfate.
The black liquor from the evaporators is either discarded or
used in leaching operations. Some plants are using dialyzers
to separate the sulfuric acid from impurities, which is recylced
for electrolyte make-up.
Volatile constituents such as arsine (AsH3) may be liberated
from the cells. The direct-fired evaporator could also be
a source of potentially hazardous emissions. Black liquor from
the evaporators can be a source of water pollution.
Slimes containing Ag, Au, Pt, Pd, Se, Te, As, Sb, Bi,
Pu and Cu are sent to treatment plants.
Ill) Melting furnace - The cathode copper contains sulfur in the
form of sulfates. The normal range of the cathode sulfur analysis
is 0.001 to 0.002 percent. Copper melting is accomplished in
reverberatory arc and induction furnaces.
4-23
-------
Since the melt copper is continuously casted, there should
be no significant emissions.
Mechanical cranes are used for charging purposes. About
250 to 300 KW of power is required to maintain the molten bath
in the arc furnaces of 50 to 80 tons capacity. The molten copper
from the furnace flows into a ladle that has multiple pouring
spouts for subsequent casting.
(12) Casting - Among a variety of possible casting operations, continu-
ous casting has become very popular. The molten copper is fed
into a mold and discharges continuously in its final shape.
The pour temperature is controlled at about 2050°F. The flow
of the precisely formed cast is maintained over pinchrolls,
on which cast cakes are cut by traveling cut-off saws. The
cast cakes are marketable at this point.
(13) Slime treatment - The insoluble metals and compounds that settle
to the bottom ^ne tanks during the electrolytic cycle are
screened and pumped to a slime-treatment plant for recovery
of precious metals and by-products. There are many recovery
processes for slime treatment. From raw slimes, selenium is
recovered and sent to selenium plants for recovery. Tellurium
is also recovered.
4.4.4 Electrowinning Method
In principle, the electrowinning method is the same as
the electrolysis process, except that the electrowinning method
bypasses the smelting operation and treats the copper concentrate.
Electrowinning is an alternative method of producing finished
copper from copper concentrate solution or copper leach solu-
4-24
-------
tion. Although electrowinning has been limited to treatment
of oxidized minerals, recent attempts were made to treat sulfide
ores by this method. The attempts were successful economically
but not technically. Anaconda Aluminum Company in Montana and
18
Duva Company in Arizona are engaged in hydrometallurgically
processing sulfide ores on pilot plant scale and each has started
construction of a full scale plant.
4.5 MAJOR POLLUTANT SOURCES
The converter, reverberatory furnace and ore crushing opera-
tions are the most significant sources of emissions in the copper
industry.
0 Copper converter - About 240 pounds of particulate and
3500 pounds of sulfur dioxide are emitted per ton of copper
produced. It is estimated that approximately 32,000 tons per
year of particulates are emitted. This annual emission rate
from converters represents 13 percent of the total emissions
from the copper industry. The converter operates at an elevated
temperature of approximately 2200°F. Fumes from the converter
contain lead, antimony, arsenic, bismuth, selenium, tellurium,
zinc, cadmium, and thallium. Slag from the converter contains
iron, silica and copper as well as varying quantities of poten-
tially hazardous materials.
0 Reverberatory furnace - The emission factor for reverbera-
tory furnaces is 206 pounds of particulate per ton of copper.
Table 4.10 shows the elements that are present in the particulate
emissions and their amounts. Exit gases contain 1 to 2 percent
S02 and 13 percent CO2. The gases are released at a temperature
4-25
-------
of 700°F and at a rate of 50,000 SCFM. Slag formed from the
furnace also contains various amounts of the elements shown
in Table 4.10.
0 Ore crushing - Approximately 2 pounds of particulate
are emitted per ton of ore processed. In 1969 crushing operations
had only limited controls and nearly 170,000 tons of particulates
per year were emitted from copper ore crushing operations in
the United States. In addition, there are some dust problems
from material handling. Composition of the dust emitted is
the same as that of the ore handled. Elements present in the
ore (as shown in Table 4.2) include silver, lead, arsenic and
selenium.
4-26
-------
REFERENCES FOR CHAPTER 4
1. Schroeder, H. J. and John W. Cole. Copper, In: Minerals
Year Book. Vol I - II. Bureau of Mines. 1971.
2. Ageton, R. W. and G. N. Greenspoon. Copper, In: Bureau
of Mines Bulletin 650, Mineral Facts and Problems, 1970
Edition.
3. Kirk-Othmer. Encyclopedia of Chemical Technology.
New York, John Wiley and Sons, Inc. 1966.
4. Private communication. White Pine Copper Company.
White Pine, Michigan.
5. Ealy, G. K. Concentration of Copper Oxides by Flotation
at Nicimiento. Mining Congress Journal. March 1973.
6. Ludeke, K. L. Soil Properties of Materials in Copper Mine
Tailing Dikes. Mining Congress Journal, August 1973.
7. Semarau, K. T. Control of Sulfur Oxide Emissions from
Primary Copper, Lead and Zinc Smelters - A critical
review. Journal of Air Pollution Control Association.
April 1971. Vol. 21, No. 4.
8. MacAskill, D. Fluid Bed Roasting: A Possible Cure for
Copper Smelter Emissions. Engineering and Mining Journal.
July 1973.
9. Vandegrift, A. E. and Others. Particulate Air Pollution
in the United States. Journal of the Air Pollution
Control Association, Vol. 21, No. 6. June 1971.
10. Compilation of Air Pollutant Emission Factors. Prepared
for EPA. Contract No. CPA-22-69-119.
11. Donovan, J. R. and P. J. Stuber. Sulfuric Acid Production
From Ore Roaster Gases. Journal of Metals. November 1967.
12. Exhaust Gases from Combustion and Industrial Processes,
Engineering Science, Inc., Washington, D.C. October 2,
1971. Distributed by National Technical Information
Center.
13. Industrial Gas Cleaning Institute, Inc. Air Pollution
Control Technology and Costs: Nine Selected Areas.
Prepared for EPA. September 1972. Contract No. 68-02-0301
14. Phillips, A. J. The World's Most Complex Metallurgy.
Transactions of the Society of AIME. Vol. 224. August
1962.
4-27
-------
15. Flash Smelting Process for Copper Concentrates. The Mines
Magazine. August, 1973.
4-28
-------
5.0 LEAD INDUSTRY
5.1 INDUSTRY BACKGROUND
In 1971, the United States mined about 0.58 million
short tons of lead, which was 15.0 percent of the world's
total; we consumed 1.43 million short tons (primary and
secondary metal), which was 0.38 percent of the world's
consumption. In 1968, domestic primary metal represented 33
percent of apparent demand, secondary metal 38 percent,
metal imports 32 percent, and stock drawdown 6 percent.
Fifty percent of the total supply was consumed by the trans-
portation industry, 18 percent by gasoline refineries and 18
percent by the construction industry. The remaining 14
percent was consumed for such other uses as ammunition,
communication, and home maintenance.
The United States demand for lead in the year 2000 is
expected to be from 2.52 to 4.14 million tons. Table E-l in
Appendix E lists the lead producing mines in the United
States and Table E-2 presents mine production of recoverable
lead in the United States by state.
Missouri, the leading lead-producing state, accounted
for about 74 percent (429,600 short tons) of the domes-
tically mined lead in 1971. Other significant lead-pro-
ducing states are Idaho, Utah, and Colorado. These three
states produced about 23 percent of the total U.S. lead in
1971. The lead ore imports were primarily from Canada,
5-1
-------
Peru, Australia, and the Honduras. Secondary lead production
provides a significant amount of the domestic supply.
Ore output from the mines varies widely from a few tons
per day to over 10,000 tons per day. Generally, deposits in
the western states contain higher grade ore and are more
costly to mine and process than the deposits in Missouri.
The lead mines are located in remote areas populated
mainly by people who depend upon the mines for employment.
There were 120 domestic mines operating in 1969.
The toxicity of lead to humans seriously limits the
marketing of lead and lead products, especially in urban
areas. Another limitation is the dependence of domestic
smelters on foreign lead ore sources.
5.2 RAW MATERIALS
The primary domestic lead ore is derived from the
sulfide miner?1 - a. Table 5.1 lists the lead-bearing
minerals by name and composition. These minerals are
briefly described below:
Table 5.1 LEAD MINERALS, BY NAME, COMPOSITION
Mineral
Galena
Angles! to
CeruGsite
Pyromorphite
Vanauini te
Crocoitc
\\ulf cnite
Linar i te
Composition
PbS
PbSO,
PbCOj
Pb5ci{po4)3
Pb5ci(vo4)3
PbCrO .
4
PbMoO
PbO -CuO-SO-, !1.,0
Lead, I
8 G . (>
68. 3
77.5
7G. 3
73.0
63.9
56.4
5-2
-------
Angles!te: A brittle, lustrous lead sulfate. Its opacity
varies from transparent to opaque.
Cerussite: Lead carbonate. Its color varies from white to
grayish adamantine.
Crocoite: An orange mineral consisting of lead chromate
PbCro..
Galena: A lead sulfide, PbS, the most common ore of lead,
containing 86.6 percent lead. It usually contains silver;
when the percentage of silver exceeds that of lead, it
becomes silver ore. The metallic minerals most commonly
associated with galena include pyrite (FeS2), sphalerite
(AnS), chalcopyrite (CuFeSO, tetrahedrite (SCu^-Sb-S ) ,
bournonite (3PbS-Cu2S-Sb2S ) and other sulfosalts. Gangue
minerals associated with galena include quartz, calcite,
dolomite and other carbonates, barite, and fluorite.
Linarite: A natural hydrous sulfate of lead and copper
found in the oxide zone of metalliferrous lodes.
Pyromorphite: A green lead ore, member of the apatite
group. Found in oxidized zones of lead deposits. Some
specimens of pyromorphite have been reported to contain
uranium.
Vanadinite: A natural chlorovanadate of lead. Found in New
Mexico, Arizona, Africa, Scotland, and USSR.
Wulfenite: A mineral sometimes associated with calcium,
chromium, and vanadium. Found in veins with ores of lead in
Massachusetts, New York, Pennsylvania, Nevada, Utah, New
Mexico, and Arizona.
Characteristics of the ores of some states are described
briefly below.
Idaho (Coeur D'Alene District, Idaho) - Chief ore constit-
uents" are galena, sphalerite, tetrahedrite, and pyrite.
Quartz, siderite, calcite, colomite, and barite are the
common non-metallic gangue minerals. Grade and composition
of the ore varies greatly in different parts of the dis-
trict. One ore carries 2 to 10 percent lead, 2 to 10 per-
cent zinc, a trace to 0.6 percent copper, and 1 to 30 ounces
of silver per ton. An estimated average grade of the dis-
trict is 4.7 percent lead, 3.8 percent zinc, 0.2 percent
copper, and 7.5 ounces of silver per ton.
Utah Region - Following are the lead-producing districts: 1)
West Mountain (Bingham) district in Salt Lake County, 2)
Park City district in Summit County, 3) Ophir district in
5-3
-------
Tooele County, 4) Tintic district in Juab and Utah Counties,
5) Blue Ledge district in Wasatch County. Ore occurs in
fissure veins, breccia pipes, and replacement bodies mainly
in limestone beds. Chief ore minerals are galena and
sphalerite, with small quantities of tetrahedrite and
chalcopyrite. Gold, silver, and bismuth are supporting by-
product constituents. Estimated average grade of ore in the
region is 8 percent lead, 5.5 percent zinc, 0.4 percent
copper, 3 to 7 ounces of silver, and a trace to several
tenths of an ounce of gold per ton.
Montana - Copper is the major mining product. Lead may be
considered a by-product of the zinc, occurring in a ratio of
about 1 part lead to 5 parts zinc on the district average.
Metaline District, Washington - A typical district ore grade
is roughly 1.5 percent lead, 3 percent zinc, traces to 0.1
percent copper, and trace to 0.5 ounce of silver per ton.
Colorado Districts - The bulk of Colorado output comes from
two regions:1) parts of Lake and Eagle Counties, and 2) a
region in the mountains of southwestern Colorado in San
Juan.
Practically all the lead-bearing ores of Colorado are com-
plex mineral mixtures of copper, lead, zinc, iron, gold,
silver, and other elements; the ores are of widely varying
grades. An estimate of typical ore grade of the Leadville
region is approximately 9 percent zinc, 1.5 percent lead,
1.5 ounces of silve^ er ton, and small but recoverable
quantities of i copper. An estimated average grade
of ore in curr ^ operating mines in southwestern Colorado
is 3 percent zinc, 3 percent lead, 0.7 percent copper, 2 or
3 ounces of silver, and trace to 0.1 ounce gold per ton.
Arizona and New Mexico Districts - Types range from typical
fissure veins and limestone replacement bodies to contact
metamorphic deposits. Almost all deposits contain gold,
silver, copper, lead, and zinc. A typical assay of ore from
the larger, more constantly producing areas would approxi-
mate 7 percent zinc, 3 percent Pb, 0.6 percent Cu, one to
several ounces of silver, and trace to 0.1 ounce of gold per
ton.
Nevada Districts - The most stable and productive mines are
in Eureka, Lincoln, and Elko Counties. Types of ore de-
posits are various, but nearly all are small, irregular and
high grade. Lead is often the least important of the valued
ore constituents.
California Districts - The Darion Ingo County deposits are
the major lead sources _'."i California. These deposits are
principally veins and limestone replacement bodies con-
taining lead and zinc sulfides. Oxidized ores also are
reported.
5-4
-------
5.3 PRODUCTS
In addition to the various grades of lead produced,
several coproducts and by-products are recovered. Copper,
gold, silver, and zinc are the major coproducts or by-
products associated with lead ores; minor by-products are
antimony, bismuth, sulfur, and tellurium. Concentrator
tailings in Missouri are used as highway and railroad
ballast, dolomite limestone for agriculture, and smelter
slags as construction materials. Table 5.2 shows the co-
product and by-product relationships of lead and other
metals.
Table 5.2 COPRODUCT AND BY-PRODUCT RELATIONSHIPS
OF LEAD AND OTHER METALS1
Souur
l.rail
Do .
Do
Do
Do
Do
Do
Do
Do
Do
/me
Silver
Fluorine'
£ir
Uranium
\\.' \Virl
I'rothicl 1', nil Quantity oil
pi
tpll! ,
tfllt
. HiMiiutli 1.000 pu Mils 700 100.0
\ntiiiiony Slmit i
Irlhmuui .000 ,
MlM-r .000 '
/mi .000 1
(,olcl .000 i
('upper .000 1
Mum- tli
Siiltur .000 li
1 e.i.l .000 si
li . . U
1( U
1. io
U Short ti
1. 1.
1, 1.
1.0 lit
Mils S(i
,,-s 5,r,T:i
l tons .r>7
i cs T>
I tuns H
W
^ inns \V
it tons 2H't
(ill
li
1
us •!«
21
VV
rj4.;l
2') 7
17.0
10.7
fi. 1
.7
7S.H
IS). 2
l.li
.4
fiitia
5.4 PROCESS DESCRIPTION
Figure 5.1 illustrates the lead industry segment. The
primary lead smelters in this country use essentially the
same processing steps, with some differences in equipment
and details of operation. The processes are mining, ore
concentration, leaching, smelting, pyrometallurgical re-
fining, electrolytic refining, and finishing.
5-5
-------
5.4.1 Mining
(1*; Mining - Lead ores are largely mined by underground
methods employing either open or supported stops. The
stopping includes block caving, room and pillar with and
without rock bolts, shrinkages, cut-and-fill, and timbered
methods.
Very little air pollution occurs in lead mines. Large
amounts of solid waste are generated and are used in highway
construction operations. When the waste cannot be used, it
is dewatered and impounded to minimize atmospheric pollu-
tions.
Water contamination depends on the acidity of the water
leaching through the waste pile. Mine waste water from the
new Lead Belt mine in Missouri is basic (pH 7.8 to 8.2) and
would precipitate heavy metals into existing settling ponds.
At that mine, copper was found to be the most toxic heavy
metal present.2 The heavy metals in the tailings discharge
v-ere not toxic enough to endanger fish life. At one mine in
Missouri approximately 3500 to 5500 gpm of water is pumped
for mining operations.
The ore is disintegrated by lightweight percussive and
rotary percussive drilling machines. Power shovels, scrapers,
id mucking machines are used for leading. Transportation
., by electric or diesel-powered motorized trains operating
•i heavy-gage tracks.
4.2 Concentrat ion
ineral dressing and concentration - The mined ore is normally
"Numbers refer to corresponding processes in Figure 5.1.
5-6
-------
r'
•EFIIIIIIC
PYROMETDLURGICAL SOFTENING
Figure 5.1. Primary lead production.
-------
in the lead-zinc flotation process are sodium isopropyl
xanthate, diethyl dithiocarbamate, mixed alcohols, zinc
sulfate, sodium cyanide, copper sulphate, and sodium di-
chromate. Pine oil and cryslic acid are used as frothers,
and sodium carborrate and calcium oxide as conditioners. The
flotation process requires approximately 1500 to 2000 gpm of
water.
Crushing operations generate about 2 pounds of par-
ticulate emissions per ton of concentrate produced. About 5
pounds per ton are emitted from material handling and stock-
piling.
Spent liquor from the flotation process and the mine
waste liquor and tailings flow by gravity to settling ponds.
The flotation reagents form a surface film in the ponds and
contribute to stream pollution by promoting growth of
bacteria and undesirable algae. Where more complete water
recovery is required, the tailings may be thickened, fil-
tered, and conveyed to a tailings pile. Disposal of the
tailings at the mine site, causes no substantial solid waste
problem but may cause serious water pollution.
The ore charge is run over a grizzly (coarse screen)
through an ore bin to the crusher. Belt conveyors convey
the crushed material to a ball mill and then to a classifier
The concentrate is transported to smelters by truck or rail.
Care must be taken to prevent losses by leakage from truck
bodies or railroad cars. Truck bodies are covered to pre-
vent dust losses. Most high-grade ores are shipped in
5-9
-------
sealed steel drums to prevent loss through leakage, dusting,
or pilferage.
5.4.3 Leaching
(3) Pressure leaching - To simplify subsequent smelting oper-
•r"
ations, concentrated ore, or in some cases direct-mined ore,
is pressure leached to remove most of the copper and some
other elements such as arsenic and antimony. The leaching
is done under pressure at high temperatures. The extracted
copper is recovered by precipitation.
Leaching should cause no significant atmospheric emis-
sions, since the process is conducted under pressure in an
autoclave. The waste leach solution may be a source of
serious water pollution. Table 5.4 shows a typical analysis
of the pressure leach-feed, the residue, and the leach
solution.
Table 5.4 TYPICAL ANALYSIS OF PRESSURE LEACH -
FEED, RESIDUE, AND LEACH "SOLUTION
Autoclave
Cd
Co
In
Ni
Pb
Zn
Cu
As
Sb
Sn
Fe
Mn
Mg
Ag
Bi
s
insolubles
Ca
feed, %
0.15
0.025
0.08
0.40
50.6
8.7
6.46
2.2
2.0
0.07
7.8
0.14
0.15
131. 7a
0.006
16.4
2.3
0.2
Autoclave
Cd
Co
In
Ni
Pb
Zn
Cu
As
Sb
Sn
Fe
Mn
Mg
Ag
Bi
S
insolubles
Ca
residue, %
0.02
0.01
0.04
0.11
51.2
1.20
0.83
2.0
1.8
0.06
6.7
0.10
0.10
140. la
0.006
9.4
3.0
0.2
Autoclave
Cd
Co
In
Ni
Pb
Zn
Cu
As
Sb
Sn
Fe
Ag
Bi
8
&"«•
solution , g/1
0.85
0. 13
0. 06
1.78
trace
49. 5
47. 8
1. 36
0. 15
trace
4.0
trace
0.0
67 . 6
44.0
0.0
Value for Ag given in oz/ton.
5-10
-------
5.4.4 Agglomeration
Ores are agglomerated to facilitate subsequent handling
in the smelting process. They are first pelletized and then
sintered. Sintering, also considered part of the smelting
process, is discussed in Section 5.4.5.
|4) Pelletizing - Various concentrates, return sinter, crude
ore, zinc plant residue, and by-products such as flue gas
dusts are blended and conditioned in a mill by the addition
of water and then pelletized. A typical charge contains 30
to 45 percent lead, 7 to 12 percent sulfur, 10 to 12 percent
insolubles, and 6 to 10 percent lime. The pelletizer is
oil- or gas-fired to maintain an exit gas temperature of
600°F.
Particulates are emitted from the pelletizer. Their
composition should be essentially the same as that of the
pelletized product.
The charge is conveyed to a hopper and then to a sinter
machine.
5.4.5 Smelting
In the smelting operation the concentrate is first sin-
tered (roasted) to convert the lead sulfide to lead oxide.
The lead oxide is reduced in the blast furnace to metallic
lead.
(5) Sintering - Sintering is a universal practice in the lead-
smelting industry. The purpose of sintering is to reduce
the sulfur content of the concentrate by roasting and to
produce a strong, porous mass suitable for reduction in the
5-11
-------
blast furnace. Such elements as arsenic and antimony, Cd,
Hg are volatilized. The reaction takes place at a temperature
of 1100°F. Sintering takes place on a moving metal belt.
Combustion takes place on the belt, and once initiated does
not require external heat.
The sintering process is a potentially significant
source of air pollution. Substantial quantities of sulfur
dioxide are emitted; in many plants this SO_ is converted to
sulfuric acid. Offgases also contain organic vapors from
flotation reagents in the concentrate. The volume of gases
emitted is a function of machine size and material through-
put. The range is from 100 to 200 SCFM per square foot of
bed area. Temperatures of the gases normally range from 250
to 600°F. Flow rate may range from 0.80 to 1.4 SCFM per
Ib/hr of lead production.
Table 5.5 gives a typical analysis of gases from a
sintering machine.
Table 5.5 ANALYIS OF SINTER MACHINE GASES
(MISSOURI LEAD OPERATING COMPANY)7
Range Vol., %
S02 4-7
°2 4~9
CO2 3-4
N2 84-85
SO3 0.05-0.2
Dust content 25 grains/scf
Temperature 400°-665°F
Moisture content 25% by vol.
Vessel sizing; for 25,000 scfm dry gas, with gas cooling
system sized to maintain a water balance for the production
of 66° Be acid with gas strength of 4% SO2 at 21,000 scfm.
5-12
-------
The dust from the sinter machine contains Pb, Sb, Zn,
Cd, Ge, Se, Te, Tn, Tl, Cl, F, and As. These constituents
are usually collected for subsequent recovery of antimony
and other elements. Particulate emissions are approximately
500 pounds per ton of lead produced. Table 5.6 identifies
the partial composition of the feed and product from a
sintering machine.
Table 5.6 TYPICAL SINTERING MACHINE FEED
AND PRODUCTS
'"•"lit'-tlC
l.i-a.1
In-i'luble
(.'iilt'ium oxide —
7ii r
t'lijiuiuni —
SlUlT <>"'"
.percent -
iio . . _
d.j
.do
. . . . do - -
.-.do .
... do . -
. do -
es per toil .
rtrt
•1. 0
3J 0
>.). 4
4. t)
4. 5
10. 6
5. 0
0 05
30 1 50
.Tii./rr
2. 9
35 5
0. 7
10. 0
10. 3
1 4
10 0
0 04
30 150
The sinter is conveyed on belt conveyors to storage.
(6) Blast furnace - In the U.S., blast furnaces are used to
reduce lead oxides to metallic lead. Limestone, other
fluxes, and coke are mixed with the sinter and charged to
the blast furnace with limited quantities of air. Some ore
and'lead scrap are also charged directly to the furnace.
Fuel can be liquid or gaseous. The blast furnace operates
at approximately 1800 to 1900°F.
Since most lead ores contain some zinc and many lead
smelters treat zinc-plant residues having high lead and zinc
contents, blast furnaces often produce large tonnages of
zinc as well as lead.
5-13
-------
The bullion product from the blast furnace contains Pb,
Cu, Au, Ag, Sb, As, Bif Sf In, Cd, Ni, Fe, Te, and other
Q
elements. Table 5.7 shows a typical blast-furnace charge,
and Table 5.8 gives the analysis of typical inputs and
outputs from a blast furnace.
Table 5.7 TYPICAL BLAST-FURNACE CHARGE3
Components Height, Ib
Sinter 2750-3600
Coke 270-360
Cleanup products 0-200
Slag (direct) 0-500
Silica (60% SiO~) 0-80
Limerock (52% CaO) 0-60
Cadmium residue 0-20
Refinery dross 0-75
Baghouse product 0.75
The slag, formed at the peak temperature of the furnace,
contains oxides of Fe, Ca, Si, Al, Mg, and Mn. It also
contains the elements Zn, Cl, F, Ge, As, Pb, Sb, Cd, Cu, and
Q
Ag in significant concentrations. This slag is further
treated in a fuming furnace and deleading kiln to recover
additional lead and zinc oxide. All blast furnaces in the
U.S. have control devices. The uncontrolled emission rate
is about 250 pounds of particulate per ton of lead produced.
q
The inlet dust loading averages 6.0 grains/scf. Concen-
trations of trace metals in the dust exiting from the con-
trolled exhaust stream are as follows: Cd and V 0.01-0.1
ppm; Cu 0.01-0.1 ppm; Mg 1-10 ppm; Mn, Ni, and Sn 0.01-1.0
ppm; Pb 0.1-100 ppm. Composition of the entrained dust,
which is friable and minute, is similar to that of the
blast-furnace charge. The fumes (containing Pb, Sb, Se, Te,
5-14
-------
Cl, F, In, Tl, Zn, Cd, and As) are sent to cadmium treatment
plants.
The blast-furnace exhaust gas flows depend on furnace
size; generally they range from 5000 to 9000 SCFM. Varying
amounts of dilution air enter the furnace exhausts. The
average flow rate of exhaust gases is about 0.6 SCFM per
Ib/hr of product. The temperature of blast-furnace gases
is around 1800°F. The sulfur dioxide content of exhaust
gases is low, varying considerably from 0.005 to 1.5 percent.
Carbon Monoxide emissions are considerable and concentrations
in blast-furnace gas is generally on the order of 2% CO.
Table 5.8 TYPICAL BLAST-FURNACE MATERIALS AND PRODUCTS
11
S inter Analysis, %
Aga 10-21
Cu 0.6-1.5
Pb 28-36
S 0.75-1.6
Fe 12-15.5
Si02 13.5-15.6
CaO 9.0-10.5
Zn 9.5-12.5
Slay Analysis, %
Aga 0.05-0.15
Cub 0.10
Pb 1.5-3.5
FeO 25.5-31.9
CaO 14,3-17.5
Zn 13.0-17.5
insol 22.6-26.5
MnO 2.0-4.5
Asb 0.10
Sbb 0.10
Bullion Analysis, %
Aga 40-100
Aua 0.05-0.1
Cu 1.0-2.5
Fe 0.6-0.8
As 0.7-1.1
Sta 1.0-1.75
i 33i- 0.01-0.03
!
1
a) Ag and Au, oz/ton.
b) Variable, depending on the furnace charge.
5-15
-------
(7) Fuming furnace - Slag is heated in an oil- or gas-fired
furnace to produce a matte, and speiss which contains As,
Sb, Cu, Ag, Si, and Fe. The matte is sent to a copper
smelter for further treatment. The furnace also produces
slag containing Fe, Ca, Si, Al, Cu, Mg, F and Cl. This slag
is usually discarded, although one plant treats it to
recover copper and silver.
Substantial quantities of fumes containing Pb, Zn, Ge,
Sb, Cd, Se, Cl, and F are generated by the fuming furnace.
The dust from this exhaust is collected and sent to a de-
leading kiln.
(8) Deleading kiln - The charge containing the collected dust
from the fuming furnace and carbon is heated in a gas- or
oil-fired kiln. Zinc oxide is generated and recovered for
sale; it contains Ge, Pb, and Sb as impurities.
The lead oxide fumes from the kiln contain Sb, Cd, Se,
Ge, Cl, and F, which are collected and recirculated to the
blast furnace.
5.4.6 Refining
Although the smelted ore produced from pure ores (for
example that from southeast Missouri) may require no further
treatment, most of the blast-furnace lead, which is derived
from more complex ores, is refined.
Refining includes dressing, softening, desilverizing,
and various other elemental recovery processes.
5.4.6.1 Prossing - The primary purpose of dressing is to
remove copper. In many smelters, the dressing immediately
5-16
-------
follows the tapping of the bullion blast furnace; in other
smelters, the bullion is transported to the refinery for
dressing. The charge is heated in the dressing kettle, then
cooled to below the freezing point of copper (700 to 900°F).
Copper and many impurities that were soluble in the hot
bullion rise to the surface and are skimmed off.
Dressing is done by two processes: soda matte and
continuous.
(9) Soda matte process - The blast-furnace bullion is added to
the dressing kettle and treated as described above. Soda
ash, litharge, baghouse dust (PbO), coke, and sulfur (if the
sulfur content of the dross is low) are also added. The
dressed bullion is transferred to a lead refinery, the dross
is smelted in a reverberatory furnace with the addition of
pig iron and silica to separate the dross into speiss (20-
30%), matte (10-15%), slag (2-4%), dust (3-5%), and lead
bullion (50%) . The speiss and matte are sent to a copper
plant for recovery.
Dressing operations emit about 20 pounds of particulate
per ton of lead produced. The collected fumes and the slag
are recirculated to the blast furnace.
ilO) Continuous dressing - Continuous dressing is used when the
charge contains a high percentage of sulfur. The hot
bullion is intermixed with cooled bullion and as its tem-
perature is reduced, copper is rejected as mixed sulfide
crystals, which float to the top of the bullion bath.
5-17
-------
Atmospheric emissions are essentially the same as in the
soda matte process.
5.4.6.2 Softening - The drossed lead bullion is further
refined to remove As, Sb, and Sn, either pyrometallurgically
or electrolytically. Pyrometallurgical softening (usually
referred to as pyrometallurgical refining) entails four
(11)(12) alternative processes: (1) the reverberatory process, (2)
(13)(14)
the kettle process, (3) the Harris process, or (4) the
continuous softening process. The lead bullion from the
softening furnace is desilverized with the addition of zinc
to separate a dross that contains all the noble metals.
This dross is retreated to recover the zinc for reuse. The
residual metal is very rich in silver.
(15) (16) Desilverizing and Degolding - The softened lead bullion
contains 40 to 500 ounces of silver per ton, 1 to 2 ounces
of gold, and 1 to 2 pounds of bismuth. The silver and gold
may be extracted by one of three methods, known as the
Parkes process, the Betts process, and the Pattinson process.
In the Parkes process, which is the most commonly used, zinc
is added to the hot bullion; mixtures of gold and zinc, and
silver and zinc are removed. The remaining zinc is sub-
sequently removed by vacuum distillation, chlorine dezinc-
ing, or the Harris process; vacuum distillation is most
common.
(17) Refining kettles and casting - Refined lead is fed to cast-
ing kettles, in which caustic soda and nitrate are agitated
into the metal. The metal is cooled to bring the impurities
5-18
-------
to the surface for skimming off. The lead is then cast with
mechanized casting machines.
Emissions from this process should be minor.
5.4.6.3 Electrolytic Softening (Betts Process) - The bullion
is refined electrolytically to produce pure lead cathodes
and slimes containing impurities. Process operations in-
clude electrolytic cell operation, kettle melting, and
electrolyte preparation.
18) Electrolytic cells - Refining of lead is carried out in
cells. Impure lead bullion is cast into anodes. A solution
of lead fluosilicate (PbSiF..) and free fluosilicic acid is
b
used as the electrolyte. Cathode starting sheets are made
from pure electrolyte lead. Electrolyte "reagents" (com-
binations of glue with either goulac or binderine) are
added.
The cell voltage ranges from 0.3 to 0.70 V.
119) Melting kettle - Deposited cathodes are thoroughly washed by
dipping in water and are charged to melting kettles, where
they are heated to 970°F. The molten lead is then cast into
ingots.
M) Electrolyte preparation - The fluosilicic acid is prepared
by reacting fluorspar with sulfuric acid to form hydro-
fluoric acid. This acid in turn is allowed to react with
silica.
"^) Slime treatment plant - The spent anodes with adhering
slimes are first washed. The slimes are then scraped off
and repulped, filter pressed, and dried to approximately 8
5-19
-------
percent moisture. Generally, the slimes are melted in a
small reverberatory furnace to produce a slag. This slag is
partially reduced in a second reverberatory furnace to
remove precious metals. It is then transferred to the
smelting department for production of antimonial lead, the
reduced portion being returned to the melting furnace for
slimes. Then copper and bismuth are removed from the
antimonial lead, and any selenium and tellurium fractions
are also removed by adding nitre.
The slime treatment plant can be a potentially sig-
nificant source of air pollution because the operations
require many driers and furnaces.
5.5 MAJOR POLLUTANT SOURCES
The overall emissions from the lead industry are less
compared with those of other nonferrous industries. In the
industry the sintering, blast furnace, slime treatment
operations and slag handling operations can be considered as
important sources of emissions.
0 Sintering - The gases mainly contain volatilized
oxides such as SO2, SO3, As2O3 and Sb^. The fumes which
are circulated to special treatment plants contain lead,
antimony, zinc, cadmium, germanium, selenium, tellurium,
indium, thallium, chlorine, fluorine and arsenic. Partic-
ulate emissions for the lead sintering process are approxi-
mately 520 pounds per ton. Almost 90 percent of the plants are
equipped with some kind of control devices. But the annual
5-20
-------
emissions of 17,000 tons are significant. The gases also
contain sulfur dioxide.
0 Blast furnace - Process operating temperature is
approximately 1875°F. The emission rate is 250 pounds per
ton. Particulate emissions are very friable and carry a
considerable quantity of lead ore and volatilized metals.
The fumes evolved from the blast furnace contain Pb, Sb, Se,
CO, Te, Cl, F, In, Tl, Zn, Cd and As. Concentrations of
trace metals present in the particulate emissions are 0.01
to 1 ppm Cd, 0.01 to 0.1 ppm Cu, 1 to 10 ppm Mg, 0.01 to 1
p'pm Mn, 0.01 to 1 ppm Ni, 0.1 to 100 ppm Pb, 0.01 to 1 ppm
Sn, and 0.01 to 1 ppm V. Exhaust gas temperature is around
1800°F and the sulfur dioxide content is low. The dust is
very minute in nature and requires high efficiency control
equipment.
Slag is formed at the peak temperature of the furnace
and contains oxides of Fe, Ca, Si, Al, Mg and Mn. The
elements Zn, Cl, F, Ge, As, Pb, Sb, Cd, Cu and Ag are also
present in the slag in significant concentrations.
5-21
-------
REFERENCES FOR CHAPTER 5
1. Paone, J., Lead, In: Mineral Facts and Problems. U.S.
Department of the Interior, 1970.
2. Wixson, B.C., and Others. Pollution from Mines in the
"New Lead Belt" of Southeastern Missouri. Proceedings
of 24th Industrial Waste Conference, 1969.
3. Kirk-Othmer, Encyclopedia of Chemical Technology. John
Wiley and Sons, Inc. New York, New York.
4. Vandegrift, A.E., et al. Particulate Air Pollution in
the United States. Journal of Air Pollution Control
Association. Vol. 21, No. 6, June 1971.
5. Appendix to First Edition of Denver Modern Mineral
Processing Flow Sheets, Denver Equipment Company,
Denver, Colorado.
6. Exhaust Gases from Combustion and Industrial Processes.
Engineering Sciences, Inc. Washington, D.C. October
2, 1971. Distributed by National Technical Information
Center.
7. Gibson, F.W. Smoke Handling in a Lead Smelter.
Missouri Lead Company. Boss, Missouri 65440.
8. Phillips, A.J., The World's Most Complex Metallurgy,
Transactions of the Society of AIME. Vol. 224. August
1962.
9. Krebs Engineers, High Energy Gas Scrubbing at Low
Pressure Drop. California.
10. Lee, Jr., E.R. and D.J. Von Lehmden. Trace Metal
Pollution in the Environment. Journal of the Air
Pollution Control Association, October 1973.
11. Semran, K.T. Control of Sulfur Oxide Emissions from
Primary Copper, Lead and Zinc Smelters - A Critical
Review. Journal of Air Pollution Control Association,
April 1971.
5-22
-------
6.0 ZINC INDUSTRY
6.1 INDUSTRY BACKGROUND1
In 1971, the United States produced slightly more than
half a million short tons and consumed an estimated 1.25
million short tons of zinc in addition to about 0.4 million
short tons of secondary zinc. Six leading countries,
Canada, Russia, United States, Peru, Mexico, and Australia,
2
produce more than 60 percent of the world's total. In
1969, about 63 percent of the total domestic zinc production
was from zinc ore, 18 percent from lead-zinc ore, 9 percent
from lead ore, and the remaining from all other ore sources.
In the same year, the United States consumed about 1.35
million short tons of slab zinc, 42 percent of which was for
zinc-base alloys, 35 percent for galvanizing, 13 percent for
brass mills, 4 percent for rolled zinc, and 3 percent for
zinc oxide. Tennessee, New York, Idaho, Colorado, and
Pennsylvania produce about 60 percent of domestic zinc ores.
Tennessee, with 8 of the 25 leading mines, produced approxi-
mately 25 percent of domestic output in 1969. A total of 25
states produce zinc ore. In 1968 there were 15 zinc smelt-
ers, but the number decreased to 8 in 1971. The Nation's
smelter capacity was 766,433 tons in 1971.
6-1
-------
Recoverable identified resources (reserves) are esti-
mated to be about 45 million tons in the United States and
235 million tons worldwide.
An estimated range of the Nation's requirements for
zinc in the year 2000 is 2.46 to 4,7 million short tons.
Other metals like aluminum, may replace zinc for some uses.
If this occurs, requirements for zinc in the year 2000 will
be at the minimum of the range.
The United States is the world's leading producer of
zinc metal, followed by Japan and the U.S.S.R. Some of the
domestic companies control important zinc mines in Canada,
Mexico, Bolivia, Argentina, Peru, Australia, and Territory
of South-West Africa.
Zinc mines are mainly located in areas remote from
cities and populated by the people dependent on the mines
for employment.
Table F-l in Appendix F lists the names of companies
processing zinc ore.
The zinc industry suffered several setbacks in 1970
after steady growth during the preceding 2 years. The
supply and consumption of all zinc elements declined, and
many mines and smelters closed in 1971. In 1972 the con-
sumption of slab zinc rose to a new high level, but most of
the Nation's demand was met by imports. Table 6.1 lists the
principal companies and their smelter and electrolytic
refinery capacities in the years 1969, 1970, and 1974.
6-2
-------
Table 6.1 ZINC SMELTER AND ELECTROLYTIC REFINERY CAPACITIES
Company
Electrolytic plants:
ASARCO
American Zinc Co
Do
The Bunker Hill Co
Horizontal-retort plants:
ASARCO
American Zinc Co
AMAX Lead & Zinc Co
Eagle-Picher
Industries, Inc.
National Zinc Co
Vertical-retort plants:
Matthiessen & Hegeler
Zinc Co.
New Jersey Zinc Co. ....
Do
St. Joe Minerals Corp. .
Total
Plant location
Corpus Christi
Tex.
Sauget , 111 .
Anaconda, Mont. . . .
Great Falls, Mont.
Kellogg, Idaho. . . .
Amarillo Tex
Dumas Tex
Blackwell, Okla. . .
Henryetta, Okla...
Bar tie svi lie
Okla.
Meadowbrook,
W. Va.
Depue , 111
Palmer ton, Pa
Monaca , Pa
1966
100.0
75.0
90.0
162.0
92.0
52.5
57.0
94.0
45.0
47.1
48.0
56.0
118.0
180.0
1,216.6
1967
100.0
75.0
90.0
162.0
98.0
52 5
57.0
94.0
45.0
45.3
48.0
56.0
118.0
200.0
1,240.8
1968
100.0
75.0
90.0
162.0
110.0
52.5
57.0
94.0
45.0
52.0
48.0
70.0
120.0
215.0
1,290.5
1969
100.0
80.0
57.7
162.0
110.0
52.5
57.0
94.0
61.0
48.0
70.0
120.0
215.0
1,227.2
1970
100. 0
80.0
162.0
110.0
52.5
57.0
94.0
53.0
48.0
70.0
120.0
215.0
1,161.5
1971
100 0
162 0
10Q 0
52 5
86.4
53 0
120 0
215.0
897.9
1972
i fin n
1 no n
S9 S
•Jt. . _>
72.0
s°, n
1 20 0
215.0
721.5
1973
1 r\r\ n
i.UU . U
1-70 n
/ £ . U
i nn r\
iuy . u
C.O c.
jiL , 3
co n
J J . U
i ?o n
260.0
766.5
1974
lUO . 0
Q/, r\
OH . U
i n o r\
iuy. u
^9 t;
Jf. . J
co n
J J • U
1 Of) n
260.0
778.5
•'•Now owned by AMAX Lead & Zinc. Co.
-------
6.2 RAW MATERIALS
Many minerals contain zinc as a major component. Table
6.2 lists the zinc-bearing minerals and their chemical
formulas.
Table 6.2 ZINC-BEARING MINERALS 2
Type of ore
Sulfide-
containing
ores
Oxygen-
containing
minerals
Mineralogical name
Sphalerite
Wurtzite
Smithsonite
Hemimorphi te
{calamine)
Hydrozincite
Zincite
Willemite
Franklinite
Chemical formula
ZnS
ZnS
ZnCO,
Zn Si 0 (OH) HO
Znt.(OH),(CO.).>
Znd 632
Zn.SiO.
(Fe,Zn,Mn) (Fe,Mn)_0
Zinc content
percent
63-67
59-67
48-52
52-54
59-78
75-80
51-56
14-27
Zinc is usually found in nature as a sulfide. Most
other zinc minerals probably have been formed as oxidation
products of the sulfide. Zinc sulfide is often associated
with the sulfides of other elements, especially those of
lead, cadmium, iron, and copper. Characteristics of the two
ores are described below:
Sulfide-containing ores - The principal ore minerals of
zinc are sphalerite and wurtzite.
Sphalerite; Resinous in appearance. Next to iron,
cadmium is the most common impurity (typical cadmium
content of zinc concentrate runs about 0.3%). Ger-
manium and galena also occur in sphalerite deposits
formed at relatively low temperatures. Traces of
indium and tin can occur in sphalerite formed at high
temperatures. Common varieties of sphalerite are
yellow or resinous brown. The pure and nearly color-
less variety is known as cleiophate; the dark brown to
black variety with more than 10 percent Fe is known as
marmatite.
6-4
-------
Wurtzite: Hexagonal form of the sulfide; stable at
temperatures above 1020°C. It is a relatively rare and
less stable zinc sulfide.
Oxidized forms of zinc minerals - Most of these min-
erals are minor sources of zinc. They result from the
oxidation of the sulfide by weathering. Smithsonite and
hemimorphite are important ore minerals in many localities.
Franklinite and zincite are the major minerals in the ores
of Sussex County, New Jersey.
6.3 PRODUCTS
Zinc and zinc oxide are the primary products of the
zinc industry. Several other valuable metals are also
recovered from zinc plant residues; these residues are
sometimes shipped to other nonferrous smelters for treat-
ment. Zinc is also available as a coproduct from lead and
copper smelters. The by-product-coproduct relationships are
shown in Table 6.3.
Sulfuric acid is also produced by the zinc industry.
In 1969 approximately 1.1 million tons of sulfuric acid was
produced from stack gases evolved in roasting of zinc
sulfide ores.
Table 6.3 ZINC BY-PRODUCT AND COPRODUCT RELATIONSHIPS
S*Hlf 1.01)
\V
SilM'l
Slilflll
Cold
(:.,!( Kim
<.0|,|HT
•stone
718
W
r>
•11 n
12 (i
:i.»
\A
.H
.4
\V
W VV'ilhhclil to avoiil
ata.
10.7
do ]'2 2.2
do !l 1.8
do 2 A
Mioit tons !i
OSIIIR individual company confidential
6-5
-------
6.4 PROCESS DESCRIPTION
Figure 6.1 illustrates the zinc industry segment. The
metallurgy of zinc is in many respects more complex than
that of copper or lead. The processes include mining,
concentration, roasting and sintering, reduction, casting,
and purifying.
6.4.1 Mining
(1*) Underground Mining - Most zinc ore is obtained by under-
ground mining. The principal classes of this method are
open shrinkage, cut-and-fill, or square set stopping method.
There is no stripping waste problem; occasionally the solid
waste and tailing piles may cause disposal problems in
heavily populated areas. The particulate emission factor
for fugitive dust from mining and milling is 0.2 pound per
ton of zinc produced.
Loading is done with diesel or electric shovels or
loaders with high capacity. Hauling is done with trucks.
The trend is toward rubber-tired, high-speed, maneuverable
4
machines.
6.4.2 Concentration
(2 ) Concentration - The zinc content of practically all zinc ore
is very low. Concentration of ores not only increases the
zinc content, but modifies the physical characteristics for
ease of processing in subsequent operations. This upgrading
process includes size reduction by crushing and grinding and
separation by flotation. In some ores the zinc is mixed
* Numbers refer to corresponding processes in Figure 6.1.
6-6
-------
JOJilULC IIB_SI«JI«J1C
Figure 6.1. Primary zinc production.
-------
with the lead too intimately to separate by flotation. In
such cases, final separation involves sulfuric acid leaching
at an electrolytic zinc plant or use of the blast-furnace
process, which produces lead as a by-product. Depending
upon subsequent process requirements, the concentrate may be
pelletized or briquetted to improve its mechanical strength.
Table 6.4 lists the elements that may be found in zinc
concentrates.
The handling, crushing, and flotation operations have
no extraordinary energy requirements. Fuel may be required
to fire pellets or briquetts.
Emissions of potentially hazardous materials during
this phase should be relatively minor. Composition of
particulates from the various operations should be essen-
tially the same as that of the raw material charged, since
the process, except for pelletizing and briquetting, are
performed at ambient temperatures. Briquetting and pel-
letizing steps are conducted at temperatures low enough to
preclude significant emissions of hazardous pollutants. The
flotation operation may pose a problem of waste water dis-
charge. Flotation is normally conducted in the neutral to
basic pH range, however, and the potential for leaching
significant quantities of hazardous materials from the rock
should be minimal.
The crushing operation produces approximately 2 pounds
of particulate emission per ton of ore. Belt conveyors are
used for internal transport.
6-8
-------
Table 6.4 ELEMENTS THAT MAY BE FOUND
IN ZINC CONCENTRATES
Element
Cu
Pb
Zn
Ag
Au
Pt etc.
As
Sb
Bi
Se
Te
Ni
Co
Cd
In
Tl
Ge
Sn
Cl
F
Zn cone.
2-1/2%
5%
50-65%
125 oz./ton
2 oz./ton
tr.
0.15%
0.05%
0.03%
-
-
0.015%
-
0.7%
0.05%
-
0.05%
0.05%
-
—
6-9
-------
6.4.3 Roasting and Sintering
Zinc concentrate is roasted to reduce the sulfur con-
tent, and sintered to prepare a charge for reduction. There
are three types of roasters in use: multiple hearth,
flash, and fluidization. Roasting and sintering are some-
times combined in a single operation although the sinter
produced by such methods is more difficult to reduce.
The product from the roasters, referred to as calcine,
may be either sintered or otherwise agglomerated prior to
pyrometallurgical reduction, or directly subjected to
electrolytic reduction.
The roasting process is a potentially significant
source of hazardous pollutants as well as sulfur dioxide.
Table 6.5 lists the elements found in the roaster charge
that may be volatilized. The percentage of a given element
volatilized, however, depends upon how the operation is
conducted. Although temperature of the operation is obvi-
ously important, other factors, such as localized reducing
or oxidizing conditions and sulfur displacement, may be
equally important.
Table 6.5 DISPOSITION OF ELEMENTS IN THE FEED TO ROASTER
Element
Zn
Pb
Cd
As
Sb
Charge Com-
position, %
55
2
0.5
0.1
0.1
Input to
Roasted
Product, %
90-98
85-95
25-50
90-100
90-100
Input to
Baghouse
Fume, -L
2-10
5-15
50-75
0-10
0-10
Amount
Unaccounted
for. *
0-1
0-1
0-2
0-1
0-1
6-10
-------
(3) Multiple-hearth roaster - The ore is fed to the upper
hearth, which serves to dry the crude material. The ore
moves from the outer edge of the upper hearth toward the
center and falls upon hearth 1, then to hearth 2, and in
like manner through the furnace. Heat is provided through a
vertical cylinder of boiler plate lined with refractory
brick. The roasting temperature usually is about 1200 to
1350°F. Fuel requirement is about 3.5 to 4 million BTU per
4
ton of feed. Total particulate emissions from multiple-
hearth roasters in the U.S. are estimated to be 4000 tons/
year.
The offgases contain about 1100 pounds of sulfur
oxides per ton of ore concentrate (333 Ib/ton of zinc).
These gases are usually treated at sulfuric acid plants and
the tail gases are discharged to the atmosphere.
The flow rate of the exit gases range from 5000 to
6000 scfm; they contain 5.7 percent sulfur dioxide.
(4) Flash roaster - The dried feed is blown into the roaster
through a specially designed burner. Air is also introduced
at optimum pressure to produce a specified air - concentrate
mixture. The temperature in the chamber is maintained at
about 1800°F. About 40 percent of the roasted product,
which contains most of the coarse material (more likely to
be high in sulfur), settles on the bottom and is exposed to
further desulfurizing. The remaining 60 percent is with-
drawn from the furnace. Sulfur content of the final product
6-11
-------
can be controlled within the range of 0.1 to 5.0 percent.
If desired, some or all of the dust products can be fed
to this furnace for further oxidation.
Offgases released from the roaster range from 10,000
l
to 15,000 scfm at temperatures of 1600 to 1800°F, They are
passed through a waste heat boiler and cooled to 600°F.
About 20 percent of the suspended dust drops out in the
boiler. The SO- content of the offgases is about 10 to 13
percent.
( 5 ) Fluidj-zation roasting - In the United States, this method is
used for roasting zinc concentrates both for pyrometallur-
gical and electrolytic processes.
The feed enters the bed, and air is introduced into the
roaster. A starting burner brings the bed temperature to
the sulfide ignition point of about 1200°F. Then no ex-
ternal heat is required. The feed is fluidized and brought
to the roasting temperature of about 1600°F. If slurry
feeding is not desired, the temperature is controlled by
water injections. The particulate emission factor (one ton
per ton of zinc produced) is much higher for the fluid-bed
roaster than for the multiple-hearth furnace.
About 65 percent of the sulfur (equivalent) generated
from the roaster is recovered. Fluid-bed roasters have
larger capacities than other types, yielding treated off-
gases at the rate of 20,000 to 35,000 scfm at 700 to 900°F,
rich enough in sulfur dioxide for use as feed to an acid
plant. The sulfur dioxide content of the offgas from the
-------
units range from 10 to 13 percent, but generally is decreased
to 6 to 8 percent in subsequent cooling and cleaning oper-
ations.
Sintering - Sintering is the most common agglomerating
process although nodulizing is used in a few plants. Feed
for the sintering machine is a mixture consisting of calcine
(or sometimes concentrate), recycled ground sinter, re-
covered dust (in some plants), sand, zinc solutions from
cadmium plants, and coal. Sintering increases the mechan-
ical strength of the material and reduces the impurities by
volatilization. Not only is additional sulfur removed, but
also lead, cadmium, mercury, and halides. Operating temper-
ature is about 1900°F. The collected fumes may be sent to
a cadmium recovery plant.
Natural gas or fuel oil is used for heating. The waste
gases from the sinter machines contain low but highly var-
iable concentrations of sulfur dioxide; concentrations
depend on the type of sinter produced and the amount of
residual sulfur remaining in the calcined ore. Table 6.6
gives typical zinc sintering operations.
Table 6.6 TYPICAL ZINC SINTERING OPERATIONS7
Case :
Total charge capacity,
tons per day
Machine size, ft
Dust in off gas,
% of feed
Off gas SO7 content, %
1
240-300
3.5 x 45
5
1. 5-2.0
2
400-450
6 x 97
5-7
0.1
3
550-600
12 x 168
5-10
1.7-2.4
6-13
-------
Particulate emissions from sintering operations are
about 180 pounds per ton of zinc. The exit gas flow, which
depends upon the feed, varies from 140 to 240 scfm per
square foot of grate. The temperature of gas ranges from
500 to 700°F. No sulfur is recovered from sintering.
The sintering machines have continuous conveyors made
of grate-bar pallets, upon which the feed material is placed
and processed. The sinter product is conveyed to storage by
belt conveyors.
(7) Nodulizing - Nodulizing is a heat-treating process used with
oxidized materials such as oxide ore concentrates or mate-
rials from roasting of sulfide ore concentrates. Generally
a rotary kiln is used. The waste gases contain about 0.1 to
0.2 percent sulfur dioxide. The fume content of waste gas,
which is removed in bag filters, is treated for recovery of
lead and cadmium.
6.4.4 Reduction Process
Reduction of zinc ores and concentrates to zinc is
accomplished by pyrometallurgical reduction or electrolytic
disposition from solution.
6.4.4.1 Pyrometallurgical reduction - The three major
pryometallurgical reduction furnaces are the horizontal
retort, the vertical retort, and the electrothermic furnace.
Blast furnaces are also used outside the United States. The
reducing atmosphere in the furnace, created by incomplete
combustion of coal or coke, reduces the zinc oxide to me-
tallic zinc. About 2500 BTU is required to produce 1 pound
of metal.
6-14
-------
) Horizontal retort - The feed material is a mixture of roasted
concentrate, sinter, and coal or coke. The optimum composi-
tion is determined by the nature of the gangue in the roasted
concentrate. The retort is typically 8 inches in diameter
and 60 inches long. Several hundred retorts are arranged
back-to-back in a furnace and are heated through indirect
heat exchange by burning of fuel, usually natural gas.
Temperature is maintained at about 2000°F. The flue gas
passes around the retorts and does not contact the material
inside the retorts or the distilling zinc vapors. The zinc
vapors are collected and condensed. If the temperature is
maintained below 2000°F, formation of unwanted blue powder
4
may take place.
The offgases, containing carbon monoxide, are either
rejected or used as fuel. Horizontal retorts emit about 8
pounds of particulate per ton of ore concentrate. At one
horizontal-retort plant, 34 percent of the particulate
emissions were less than 2.5 microns in diameter, 35 percent
between 2.5 and 5.0 microns, and 31 percent larger than 5
microns. The emissions are composed of zinc oxide and
sulfur complexes. Disposition of elements in the charge to
a horizontal retort is shown in Table 6.7.
Table 6.7 DISPOSITION OF ELEMENTS IN CHARGE TO
HORIZONTAL ZINC RETORT
Element.
Zn
Pb
Cd
As
Sb
Charge com-
position, 0
55
2
0.1
0.1
0.5
Input to
Metal, "
90-95
80-85
80 .85
0-5
0-5
Input to
Res i due, ".
5-10
15-20
5-15
80-90
80-90
Amount
Unaccoun tod
± o r, o
2-3
0-1
0-5
0-5
0-5
6-15
-------
(9) Vertical retort - Reduction by vertical retort is a continuous
operation using a briquetted sinter or calcine. The bri-
quettes are mixed with coke or coal plus a binder and fed to
the top of the unit. The retort surface is heated to about
1300°C. As the briquettes travel down to the bottom of the
unit, the zinc is volatilized, travels upwards, and is
collected in condensers at the top of the unit. Vertical
retorts emit 100 pounds of particulate per ton of ore con-
centrate.
(10) Electrothermic process - Sinter, briquette, and coke are
charged at the top of the unit. An electric current gen-
erates heat via the resistance of the charge. The vaporized
zinc is collected in a condenser, and some of the residue
from the furnace is recycled to recover zinc values.
Temperatures within the furnace are about 900°C near the
wall, 1200°C in the main body of the charge, and 1400°C and
higher at the axis.
The residues of all these retort processes contain Pb,
Cu, Ag, Au, Ni, Ge, As, Sb, Cd, Zn, In, Si, Fe, Ca, Al, Mg,
and Mn, and are shipped to lead smelters.
6.4.4.2 Electrolytic reduction - Electrolytic reduction
consists of leaching of the roasted or sintered material and
electrolysis of the leach solution.
(11) Leaching - The calcine is first leached with sulfuric acid
and spent electrolyte to separate zinc completely from lead
and all the gangue material. Lime or limestone is then
added to neutralize the solution and precipitate iron,
6-16
-------
silica, antimony, and arsenic. Zinc dust is added to the
clear leach solution to remove copper, cadmium, and cobalt.
(12) Electrolysis - The purified solution is subjected to elec-
trolysis in a series of cells to recover metallic zinc. The
voltage varies from 3.25 to 4.5 volts per cell, depending on
the deposition period, current density, temperature, acid-
ity, and electrode spacing. The recovered zinc is stripped
from the cathode, melted (usually in induction furnaces),
and cast into shapes suitable for commercial purposes.
Alloying elements can be added to meet special product
requirements.
From the solution, Cu, Ge, Cd, Ni, As, Sb, Co, and Fe
are removed as precipitate and shipped to either copper or
lead smelters for recovery of at least the copper and
germanium, and occasionally other elements. Cadmium is
usually recovered as a separate precipitate at the cadmium
recovery unit in the electrolytic zinc plant. The spent
electrolyte contains Zn, Al, Mg, Ca, Na, Cl, F, and S.
Emissions of potentially hazardous materials should be
relatively minor. Total particulate emissions from elec-
trolytic processes are 3 pounds per ton of ore concentrate.
Residues generated in the leaching and purification stages
may contain hazardous solid wastes requiring disposal; these
residues are often recycled to copper or lead smelters for
metal recovery. Table 6.8 indicates disposition of the
elements found in the charge to an electrolytic zinc plant.
6-17
-------
Table 6.8 DISPOSITION OF ELEMENTS IN CHARGE
TO ELECTROLYTIC ZINC PLANT
Element
Zn
Pb
Cd
As
Sb
Charge com-
position, %
55
2
0.1
0.1
0.1
Input to
metal , %
92-98
nil
nil
nil
nil
Input to
residue, %
2-8
98-100
0-15a
98-100
98-100
Amount
unaccounted
for, %
nil
nil
nil
nil
nil
Cadmium is removed for subsequent recovery in the
leach plant.
(13) Purification and casting - The zinc obtained from all re-
torting processes must be redistilled and fractionated for
production of high-grade zinc. Distillation separates the
lead alloy containing indium and cadmium from the zinc. The
zinc is cast and prepared for market.
When zinc is produced by the electrolytic method, the
cathode zinc is melted and cast into shapes.
Atmospheric emissions from purification and casting are
thought to be minor.
6.4.5 Zinc Oxide Production
Zinc oxide production closely resembles metal pro-
duction, since the zinc must first be vaporized whether it
is to be condensed as the metal or as the oxide. Oxidation
of the zinc vapor without its being condensed as the metal
is referred to as the 'direct1 process. If the vapor is
first condensed to zinc metal then vaporized and oxidized,
the process is called 'indirect1.
6-18
-------
The most common types of furnaces for producing zinc
oxide by the direct process are the grate furnace, rotary
kiln, and electrothermic furnace.
Hi Grate-type furnace - A mixture of zinc ore and coal is
ignited on a grate, and air is blown up through the bed.
The vapor from the furnace passes into a separate chamber,
where additional combustion air is carefully introduced to
produce zinc oxide.
!5> Rotary (Waelz) kiln - Zinc-containing material and coke are
heated. The zinc vapor passes to a combustion chamber where
air is added to form zinc oxide. Table 6.9 gives typical
operating data of a rotary furnace in Germany.
if) Electrothermic furnace - Procedures with this furnace are
similar to those of metallic zinc production except that
combustion air is added to the vapor stream leaving the
furnace to form zinc oxide. Zinc oxide is also recovered
from lead blast-furnace slags in fuming furnaces similar to
reverberatory furnaces; however, the zinc oxide produced by
this furnace is less pure than that produced by other
methods.
Atmospheric emissions from well operated and maintained
zinc oxide furnaces should be relatively minor, since the
product is being collected by the air pollution control
equipment. Pollution potential arises, however, when the
rotary (Waelz) kiln is used to volatilize Zn, Pb, Cd, As,
Sb, Sn, and Bi from residues. Such varied materials as zinc
ores, waste dump materials, jig tailings, jig slimes, table
6-19
-------
Table 6.9 OPERATING DATA OF ROTARY FURNACES
FOR OBTAINING ZINC OXIDE8
Apparatus
Utilization
Capacity
Specific load
Heat consumption
Charge
Moisture content of
charge
Waste-Gas Factors
Volume
Flue gas temperature
C0_ content
Dew point
Dust
Dust content of g/NnT
raw gas
Share below 10 y %
Chemical composition wt %
Dust Removal
Apparatus
Degree of precipitation %
Average dust content g/Nirf
of waste gases
Ton/day oxide
Ton/day/m
furnace volume
Kcal/kg charge
Nm /ton charge
°C
% vol
°C
Extraction of zinc from
slag and low-grade
oxidic zinc ores
15-50
0.3-1
20-150 for supplementary
heat; total of reaction
is exothermic
Slag and/or ore mixed
with reduction fuel
(about 30% coke fines)
2500-15,000
550-700
About 10
40-45
20-50
90
65% Zn, 8% Pb and 1.5% S
Electrostatic precin-
itator or hose filter
Above 99
Below 0.5%
6-20
-------
concentrate slimes, zinc-bearing iron ores, electrolytic
zinc-leach residues, zinc-retort residues, lead furnace
slags, tin ores and slags, and antimonial and arsenical gold
ores can be fed to a kiln. Depending upon the fume recovery
practices, emissions of hazardous pollutants can be sig-
nificant.
Emissions from the fuming furnace process may also be
significant since the slag is transferred in the open to the
fuming furnace from the blast furnace. Further, the lead
may be removed from the recovered zinc in a separate kiln,
another potential source of atmospheric emissions.
Residue from the furnaces contains some potentially
hazardous materials, particularly those from the rotary
kiln, which uses a diversity of materials as feed stock.
6.5 MAJOR POLLUTANT SOURCES
Zinc roasting and refining are the major emission
sources im the primary zinc smelting industry.
0 Zinc roasting - Of the three types of roasters in
use, the fluid-bed roaster is the largest source of emis-
sions. It emits one ton of particulate per ton of zinc
produced, whereas multiple-hearth roasters emit only 330
pounds of particulates per ton of zinc produced. About 98
percent of emissions from fluid-bed roasters are suppressed,
but still the emissions are significant. Fumes from the
roaster contain mercury, lead, chlorine, fluorine, zinc and
cadmium. Offgases also contain 10 to 13 percent sulfur
6-21
-------
dioxide from fluidized-bed type and 6 percent or more sulfur
dioxide from multiple-hearth roasters.
0 Zinc refining - The gases emitted contain CO and
varying quantities of potentially hazardous metals. The
residue which is usually shipped to lead smelters contain
lead, copper, silver, gold, nickel, arsenic, cadmium, zinc,
silicon, iron, calcium, aluminum, magnesium, germanium and
antimony.
6-22
-------
REFERENCES FOR CHAPTER 6
1. Heindl, R.A., Zinc, In: Minerals Facts and Problems.
1970 Edition. U.S. Bureau of Mines.
2. Wedow, Jr. H., Zinc, In: United States' Mineral Resources,
U.S. Geological Survey Professional Paper 820.
3. Moulds, D.C. Zinc, In: Minerals Yearbook 1969. U.S.
Bureau of Mines.
4. The U.S. Zinc Industry: A Historical Perspective.
Bureau of Mines Information Circular No. 8629. 1974.
United States Department of the Interior.
5. Vandegrift, et.al. Particulate Air Pollution in the
United States; Journal of Air Pollution Control Asso-
ciation, Vol. 21, #6, June 1971.
6. Exhaust Gases from Combustion and Industrial Processes.
Engineering Sciences, Inc. Washington, D.C.
7. Arthur G. McKee and Company - Systems Study for Control
Emissions - Primary Non-Ferrous Smelting Industry.
8. VDI-Richtlinien. Restricting Emission of Dust and
Sulphur Dioxide in Zinc Smelters. (This publication
translated from German) U.S. Department of Health,
Education, and Welfare.
9. Phillips, A.J. The World's Most Complex Metallurgy,
Transaction of the Society of AIME Vol. 224, August
1962. p. 657.
10. National Inventory of Sources and Emissions. W.E.
Davis and Associates.
11. Kirk-Othmer. Encyclopedia of Chemical Technology. New
York, John Wiley and Sons, Inc. 1964.
6-23
-------
7.0 ALUMINUM INDUSTRY
1 o
7.1 INDUSTRY BACKGROUND '
In 1971, the United States mined about 3 percent and imported
approximately 25 percent of the world's total bauxite. Jamaica,
the world's leading bauxite producer, accounted for 62 percent
and Surinam 23 percent of total U.S. imports.
The United States is the leading producer of aluminum.
We produced an estimated 35 percent (about 4 million short tons)
and consumed approximately 45 percent of the world's total
aluminum in 1971.
The U.S. aluminum demand in the year 2000 is estimated
to be 21.2 to 42 million tons. The major consumers of aluminum
are transportation, building and construction, electrical con-
tainer and packaging, consumer durables, machinery, and equipment.
In the future an increasing amount of aluminum will be consumed
in the manufacture of liquified natural gas tankers.
Three states, Arkansas, Alabama, and Georgia, produce the
entire U.S. bauxite output. Ninety-four percent of the total
bauxite is used for producing alumina, and the rest for refrac-
tories, chemicals, and abrasives.
In 1971, 94 percent of the total alumina produced in the
U.S. was used for aluminum and the remainder for abrasives,
chemicals, ceramics, and refractories.
7-1
-------
In 1968, three of the leading fully integrated aluminum
companies (ALCOA, Reynolds, and Kaiser) produced about 76 percent
of the total primary aluminum.
Plants producing alumina are generally located in coastal
areas. The aluminum plants, however, are located in areas of
low power costs, because electricity requirements for electrolytic
reduction of alumina to aluminum are high.
Table 7.1 shows the distribution of aluminum plants with
respect to population in 1971.
Table 7.1 DISTRIBUTION OF PLANTS BY POPULATION3
Number of
Plants
13
9
2
7
Percent
Capacity
41.1
28.7
5.7
24.5
Surrounding 300 Square Mile Area
Population
Less than 10,000
10-25,000
25-50,000
More than 50,000
Population/Sq. Mi.
Less than 32
32-80
80-160
More than 160
The Aluminum Company of America (ALCOA) has developed a
new electrolytic method of producing aluminum in which chlorine
rather than cryolite is used to convert the alumina. This pro-
cess is expected to reduce electric power requirements by 30
percent, to be less sensitive to power interruptions than the
process currently used, and to substantially reduce atmospheric
emissions. It is also expected to reduce total operating costs
Recently, the possibilities of purifying aluminum sulfate by
crystallization for alumina production have been explored.
7-2
-------
Though this method is technically feasible, it is not economical
4
as long as bauxite is available for the Bayer process. Develop-
ment is also under way on a method of producing aluminum metal
directly from bauxite, bypassing the production of intermediate
alumina.
The names and locations of the aluminum producing firms are
listed in Table G-l in Appendix G. Table G-2 presents capacities
of domestic alumina plants and Table G-3 gives mine production of
bauxite in the United States.
7.2 RAW MATERIALS5
The aluminum-containing minerals are alunite, amblygonite,
andalusite, bauxite, corundum, cryolite, cyanite, sillimanite,
spinel, topaz, turquoise, wavellite, and many silicates. Other
sources are aluminous shale and slate, aluminum phosphate rock,
dawsonite, high-alumina-content clays, nepheline, syenite,
saprolite, coal ash, and aluminum-bearing copper leaching solu-
tions .
Alunite ; KA1-, (SO,) ~ (OH) , Alunite is a white mineral
containing 37 percent alumina. Recently two companies
explored the alunite deposits at Cedar City, Utah and
found that they contain 35 to 45 percent alunite. The
remainder is primarily quartz.
Aluminum phosphate rock - Several deposits of aluminum
phosphate rock in Florida contain about 4 to 20 percent
alumina of 0.005 to 0.02 percent U30g.
Aluminous shale and slate - These formations, distributed
widely throughout the United States, contain 20 to 24
percent Al-O.,.
Dawsonite; NaAL(OH)2C03 is a colorless or white mineral.
Large quantities of dawsonite, which contain about 35.4
percent (by weight) of alumina or 18.7 percent aluminum
metal, are present in northwestern Colorado.
High-alumina clays: These clays, consisting mainly of
kaolinite and 25 to 35 percent alumina, occur in many
deposits in the United States.
•7—
-------
Igneous rocks: These rocks occur in Wyoming, California,
New York, and many other places in the United States.
They contain about 23 to 28 percent of alumina and
mostly feldspar.
Saprolite; Deposits of saprolite with alumina content
of 25 to 36 percent are found in southern Virginia,
South Carolina, North Carolina, Georgia, and Alabama.
Other deposits, associated with low-grade bauxite occur
in Hawaii, Washington, and Oregon.
Coal ash: Coal ash may be considered as long-range
resource. Coal that is burned to provide energy pro-
duces large amounts of coal ash; enough for extraction
of alumina and sulfuric acid.
Bauxite: Bauxite, currently the world's most abundant
source of aluminum, is classified according to the
degree of hydration of alumina.
1) Monohydrate bauxite (A1203*H20) - The two distinct
minerological forms are boehmite and diaspore.
2) Trihydrate bauxite (A120..3H2O) - Has low silica
content and is known as gibbsite or hydrargillite.
The deposits of bauxite in the United States are chiefly
composed of gibbsite and contain kaolinite as an impurity.
The major deposits are located in Arkansas; minor deposits are
in Georgia and Alabama. The iron and titanium-bearing low-grade
bauxites occur in Washington, Oregon, and Hawaii. Table 7.2
presents an analysis of bauxites from Arkansas, Oregon, Washing-
ton, and Hawaii. Table 7.3 gives the analysis of bauxite from
Georgia.
Most of the bauxite used in the United States is imported
from Jamaica, Surinam, Australia, and Guinea. Table 7.4 shows
the composition of ore from Jamaica, Surinam, and Guinea. About
90 to 95 percent of all bauxite used in the United States is
consumed for producing aluminum and the rest in the production
of refractories and chemicals.
7-4
-------
Table 7.2 CHEMICAL COMPOSITION OF BAUXITES
Cpercent)
A12°3
Si02
Fe2°3
Ti02
Loss on ignition
Arkansas
40-60
1- 20
3- 6
1-3
15.35
Oregon
35.0
6.7
31.5
6.5
20.2
Washington
38.8
6.6
28.7
4.2
21.7
Hawaii
25.9
4.7
39.4
6.7
20-23
Table 7.3 CHEMICAL COMPOSITION OF BAUXITE IN GEORGIA'
(percent)
sio2
A1203
Fe O
2 3
FeO
MgO
CaO
Na2°
K2°
H2°
Ti02
P2°5
MnO
BaO
SrO
Li02
SO3
Cl
C02
Carbonaceous matter
55.02
21.02
5.00
1.54
2.32
1.60
0.81
3.19
8.09
0.65
0.06
Trace
0.04
Trace
0.03
0.02
Trace
0.83
0.32
7-5
-------
Table 7.4 COMPOSITION OF IMPORTED BAUXITE
(weight percent)
A1203
sio2
Fe2°3
Ti02
F
P2°5
V2°5
H20,
A12°3
A1203
, total
combined
, trihydrate
, monohydrate
Jamaica
49.0
0.8
18.4
2.4
—
0.7
—
27.5
40-47
2-9
Surinam
59.8
3.8
2.7
2.4
--
0.06
0.04
31.2
59.6
0.2
Guinea
58.6
4.9
4.1
2.5
0.02
—
—
29.6
52.7
5.9
Other materials needed in the production of aluminum are
sulfur, cryolite, aluminum fluoride, fluorspar, petroleum, coke,
pitch binder, and carbon. About 47 pounds of cryolite is needed
to produce a ton of aluminum. Lately, most of the cryolite
used in the industry is produced synthetically. A typical com-
position of cryolite is 51 percent F, 12.5 percent A1203, 30
percent Na, and 0.30 percent SiO2, with 0.15 percent loss on
8
roasting.
Aluminum trifluoride (a white crystalline solid) is used
in large amounts as a component of the electrolyte melt in the
manufacture and refining of aluminum.
Table 7.5 shows the amount of raw material required for
7-6
-------
the production of 1 ton of aluminum.
(
Table 7.5 RAW MATERIALS FOR PRODUCTION OF ALUMINUM"
(one ton)
Material
Sulfur
Alumina (A120.)
Cryolite (Na^AlFg)
Alumina Fluoride (A1F3)
TP~I no-rc-n^T- (CaV )
Amount
0.01 =
1.9
0.03 -
0.03 -
0.003
(Tons)
.05
.05
.05
Anode
Petroleum Coke
Pitch Binder
Cathode (Carbon)
Total: Approximately
0.490 Prebake, .455 Soderberg
0.123 Prebake, .167 Soderberg
0 .02
2.6 tons raw material/ton Al
7.3 PRODUCTS
More than 90 percent of the bauxite in the United States
is used to make alumina and about 94 percent of this alumina
is consumed by the aluminum industry. Table 7.6 presents the
composition of alumina.
Table 7.6 TYPICAL COMPOSITION OF ALUMINA
Chemical composition:
Silica (MO..)
Ii on o\ iflc ( T^
-------
Aluminum metal and alloys are used in many products because
of their low density, high electrical and thermal conductivity,
resistance to corrosion, nontoxicity, and nonmagnetic and
nonsparking properties.
In the United States, one company recovers gallium as a
by-product. In other countries iron, vanadium, and chromium
are recovered as by-products.
7.4 PROCESS DESCRIPTION
The bauxite ore is treated to refine alumina by either
the Bayer process or the Combination Process, a modification
of the Bayer process in which the solid residue is further treated.
The Combination Process is used for treating high-silica-content
bauxites, such as those from Arkansas. The following sections
describe the processes involved in refining alumina from bauxite
and producing aluminum (see Figure 7.1).
7.4.1 Bayer Process
The commercial Bayer process for extracting alumina from
ore entails dissolving alumina in caustic and recrystallizing
it as purified A1(OH)~.
(1*) Mining - Ninety percent of bauxite in the United States is mined
by the open-pit method.
There are no significant pollution problems. The ore is
broken by drilling and blasting. Drag lines, shovels, and carry-
alls are used for loading the ore, which is transported to alumina
plants by truck, rail, or aerial tramlines.
*Numbers refer to corresponding processes in Figure 7.1.
7-8
-------
LL-_ .
o;-<
u.
4-~
.4
i
J
UECDOIVSIS
Figure 7.1. Primary aluminum industry.
-------
(2) Grinding - The ore is often washed to remove silica or clay
minerals prior to grinding. Most imported ore is dried prior
to grinding; Jamaican ore does not need grinding.
Since the ore has high moisture content, grinding produces
a very small amount of particulate (6 pounds per ton of ore).
Some water pollution from washing operations may occur.
The ground material is conveyed to the mixer by belt conveyors.
(3) Mixing and digestion - The ore is mixed with caustic soda solution
at moderate temperatures to form a slurry of 50 percent solids
content. The slurry is digested at high temperatures and pres-
sures to extract the aluminum as sodium aluminate. Monohydrates
are extracted at 290°F and 60 psi.
Emissions of pollutants are negligible. The slurry is
pumped to the digester. The digested product is pumped to a
thickener.
(4) Thickener - The sodium aluminate liquor is separated from the
residual "red mud" in the thickener in the presence of flocculants,
such as cooked starch and sent to precipitators. This red
mud contains the impurities present in bauxite, such as iron
oxides, titanium oxide, in the form of sodium-aluminosilicate,
alumina, and caustic soda. The quantity of mud formed depends
upon the type of ore and its contaminants, ranging from 650
pounds (for Surinam bauxite) to 2 tons (for Arkansas bauxite)
per ton of alumina produced.
(5) Washing and filtering (of red mud) - The red mud is either fil-
tered or countercurrently washed. The residual mud slurry is
pumped to a waste area. The wash liquor is concentrated by
7-10
-------
evaporation to recover caustics. Tables 7.7 and 7.8 lists
the major insoluble and soluble constituents of Jamaican red
mud. The red mud (residue from the thickeners) is the major
waste problem of the bauxite refinery.
Table 7.7 INSOLUBLE SOLIDS OF RED MUD
FROM JAMAICAN BAUXITE11
LOI
SiO0
2
A12°3
Fe2°3
p n
25
CaO
Na O
2
TiO»
2
MnO0
2
Miscellaneous
11.0
5.5
12.0
49.5
2.0
8.0
3.5
5.0
1.0
1.5
Table 7.8 SLURRY SOLUBLE SOLIDS OF RED MUD
FROM JAMAICAN BAUXITE11
A1203 2.5 g/kg liq.
NaOH 3.7 g/kg
Na2C03 1.6 g/kg
Na2S04 0.4 g/kg
NaCl 0.7 g/kg
Na2C204 0.1 g/kg
Specific gravity 1.008
pH 12-5
BOD 6 PPm
COD 148 ppm
7-11
-------
Table 7.9 gives chemical analyses of red muds from processing
at three different companies.
Table 7.9 CHEMICAL ANALYSES OF RED MUDS12
Coinponcn t.
l-V,0-4
A12°J
SiO.,
Tii>2
c.-.o
N,?0
Lo:;s on
i-C.ni I: ion
UV i.!-lit_ IVrrrni
Al i oa
Hob i. lr, Ala.
(Sur i nai:i)
3U-4U
i <3- ~/n
11-14
10-11
5- (>
ij-8
10.7- 11 .4
tin'u:-:i Le , Ark.
(Arl'an.sas )
55-6.,
12-15
4-3
A- 3
:,- 1 (i
2
5- in
Ri.-yiu •!(!•;
r.. '>-<>
t r.-ii-c
^.>H.::>
1 . rj- r; . 0
HI- n
(6) Precipitation - The sodium aluminate liquor from the thicken-_r^ -,
also known as aluminate liquor, is rich in alumina. The liquor
is filtered and cooled to 50 to 60°C. Controlled agitation
of the cooled liquor in the presence of recycled aluminum hydrate
crystals precipitates about 50 percent of the alumina.
The precipitate is separated, washed by filtration (usually
in rotary filters), and fed to calcination furnaces. The filter
liquor is recycled.
The remaining insoluble red mud from the first filtration
is the only pollutant.
(7) Calcination - The hydrated alumina is fed to a rotary furnace,
7-12
-------
where it is calcined to about 1200°C. This operation eliminates
about 45 percent of the water and converts the alumina into
a crystalline form in which it is shipped to alumina plants.
Table 7.10 shows the composition of high quality alumina.
o
Table 7.10 COMPOSITION OF A HIGH QUALITY ALUMINA
( 'oinpo.silinu
I Iji), cnniliiiird (hiss on i-:ilciii;itiini! ().(!.> t,<
!l;0, lulsorhecl (l..ss :il, I l<>"<')
SifV,
1-WI,
Tilt, O.UO-U
,M);
-------
The large quantity of brown mud generated in the process
is either discarded or further heated for use in cement manufac-
turing.
(9) Washer - The sodium aluminate is washed in lye, filtered, and
added to the main stream for further processing. Caustic filtrate
is recycled. No pollutants are generated.
7.4.3 Production of Aluminum
Aluminum is produced by the electrolysis of alumina in
electrolytic cells (Hall Heroult Process) . This process involves
anode preparation and electrolysis.
The raw material (alumina powder) arrives in bulk by ship
or rail. Transfer to storage bins is accomplished pneumatically
or by bucket elevator systems.
7.4.3.1 Anode plant - Most plants manufacture their own carbon
anodes and cathodes. The anode is made from petroleum coke,
reclaimed anode carbon, and pitch.
The anode-making operation consists of crushing, screening,
mixing, molding, and baking.
(10) Crushing and screening - Petroleum coke, reclaimed anodes, and
anode scrap are crushed and screened.
Some particulate emissions result from this operation.
The petroleum coke arrives at the plant in bulk and is
conveyed to storage. Wetting agent sprays are used at some
plants to control dust during handling. Material from storage
is fed to crushers, primarily by front-end loaders with enclosed
cabs. The screened material is conveyed to storage bins.
7-14
-------
(ID Paste mixing - The ground coke is preheated to a temperature
of 200°F and mixed with hot molten pitch in steam jacketed mixers.
The mixture is then allowed to cool.
Particulate emissions may be emitted from this operation.
Dry solids are drawn from the mix bins in measured propor-
tions by tram cars and fed to the mixer.
(12) Molding and baking - The cold paste is molded into anode shapes
by an anode press. The anodes are baked at 2100°F in a gas-
or oil-fired furnace to develop the required electric conductivity
and strength.
Coke and coal dusts, and fines are emitted. They are easily
controllable and do not create a significant air pollution prob-
lem. Carbon dioxide, carbon monoxide, sulfur dioxide and hydro-
carbons are emitted.13 Table 7.11 presents typical anode baking
furnace emissions.
Table 7.11 ANODE BAKING RING FURNACE EMISSIONS
Flow rate, cfm 75,000 - 184,000
Stream loading/ gr/cf
Total solids 0.021 - 0.10
HF 0.003 - 0.03
Pitch condensate 0.01 - 0.30
Quantities, lb/1000 Ib Al
Total solids 1-0 - 5.0
Hydrocarbon 0.25 - 0.75
Total F 0.15 - 0.75
Sulfur 0.35 -1.0
1) Although direct-fired ring furnaces have been used
normally for prebaked anodes, continuous tunnel
kilns are under development. Combustion conditions
are significantly different and zonal temperature
control closer. As a result the emission levels
listed above may be reduced by factors of 0.01 in
total solids and 0.02 in hydrocarbons, fluorine,
and sulfur.
7-15
-------
An overhead crane system conveys the anodes into the baking
ovens, and the finished anodes to the pot rooms.
7.4.3.2 Elect rolysis of A lumina -
Electrolytic cell - There are two basic types of electrolytic
cells, prebake multi-anode and Soderberg. The main difference
is that the prebaked anode pots provide better electrical effi-
ciency but require anode fabricating and rodding facilities.
In Soderberg pots, the anode is prepared by combining carbon
and binder in the top of the pot. Heat from the pot bakes the
anode in place. The Soderberg anode systems are further catego-
rized according to the method of introducing current to the
anodes: horizontal-stud Soderberg and vertical-stud Soderberg.
In 1970, 69 percent of the aluminum in the U.S. was produced
14
in prebaked cells and 25.5 percent on horizontal-stud Soderberg.
The principle cell operations in the prebaked anode method
are feeding the alumina to molten cryolite at 2-hour intervals,
stirring to remove a high-resistance gaseous film of CF., and
changing the carbon anodes as they are consumed. Soderberg
system operations include stud planting and pulling (changing
electrode connections in horizontal-stud type), feeding, and
stirring.
Table 7.12 compares the operating requirements of prebaked
anodes and Soderberg systems.
7-16
-------
Table 7.12 OPERATING REQUIREMENTS OF PREBAKED ANODE
AND SODERBERG SYSTEMS9
Soderberg
Prebaked
Time to produce 1 ton
KWH to produce 1 ton
Effluent gases treated
per 100,000 amperes
Water - Gas Ratio
37 hours
15,400
4,000 CFM
3.3-4.4 Gal
1,000 CF
27 hours
13,600
23,500 CFM (no hoods)
10 Gal
1,000 CF
The electrolysis of the alumina involves decomposition of
alumina by continuous current flow through an electrolytic cell
containing alumina dissolved in molten cryolite. Anthracite
mixed with soft pitch may be added to the cell as lining paste.
A small amount of aluminum fluoride is added to combine with
the impurities of alumina and to form artificial cryolite.
The cryolite dissolves the alumina at a relatively low temperature,
in comparison with alumina's melting point of 3595°F. The
temperature inside the cell is maintained at 965 to 980°C.
A large quantity of electrical energy is required. The
average U.S. plant consumes about 8.0 to 8.5 KWH/lb of aluminum;
one company, however, operates successfully consuming only 6.0
to 6.3 KWH/lb of aluminum.
During electrolysis aluminum metal is deposited at the cathode.
Oxygen is liberated from the bath and reacts with the carbon
of the anode to form carbon dioxide and carbon monoxide. The
carbon dioxide rises through the alumina covering of the electro-
7-17
-------
lytic cell, carrying small amounts of alumina dust and fluorides
that produce hydrogen fluoride on contact with the air. Almost
all industries provide for collection and control of the HF
emissions.
Spent anodes from the reduction pots are returned to the
rodding section, where the remaining carbon is stripped off
and mixed with the incoming calcine coke in the carbon plant.
The main pollutants include alumina, tar-pitch, distillation
products, inorganic fluorine compounds, oxides of sulfur, hydrogen
sulfide, carbonyl sulphide, carbon disulfide, silicon tetrafluo-
ride, and water vapor.
Emissions from the horizontal-stud Soderberg cell are 98.4
pounds of particulate, 26.6 pounds of gaseous fluoride (HF),
and 15.6 pounds of particulate fluorides (F) per ton of aluminum
produced. Emissions from the vertical-stud Soderberg cell are
78.4 pounds of particulate, 30.4 pounds of gaseous fluorides (HF),
and 10.6 pounds of particulate fluorides (F) per ton of aluminum.
Emissions from the horizontal-stud Soderberg also include hydro-
carbons .
The particulate contains Al-CU, A1F.,, Na2CO3 and carbon dust.
Table 7.13 gives representative particle sizes of effluents
from prebaked and horizontal-stud Soderberg cells.
The emissions of both particulate and fluorine compounds
from the bath increase with increasing temperature, decreasing
bath ratio of NaF/AlF., (weight percent) , and decreasing alumina
content. The hydrogen fluoride emissions are generated primarily
as a result of moisture reacting with A1F3 containing materials.
7-18
-------
Table 7.13 REPRESENTATIVE PARTICLE SIZE DISTRIBUTIONS
OF UNCONTROLLED EFFLUENTS FROM PREBAKED AND
HORIZONTAL-STUD SODERBERG CELLS 17
Size range ym
1
1 to 5
5 to 10
10 to 20
20 to 44
> 44
Particles within size range, wt %
Prebaked
35
25
8
5
5
22
Horizontal -stud
Solderberg
44
26
8
6
4
12
The HF emissions increase directly with the partial pressure
of the water.
The moisture is from the atmosphere, from mois-
ture content of Al-O.,, and from burning of the hydrocarbons
in the anodes.
The fluoride particulates range in size from about 0.05
to 0.75 ym with the majority of particles smaller than 0.25
The fluorine content of the total gases, withdrawn from the
3 19
pots or pot rooms may vary from 2 to 40 rag/ ft . Another
study reports the fluorine content of the total gas, on weight
basis, varies between 18.97 and 25,63 Kg/ton of raw material.
According to the same report, cooling the process by 5 degrees
centigrade, will reduce fluorine consumption by 0.2 Kg/ton of
raw material, while increasing the cryolite ratio of 0.1 will
20
effect approximately a 3 Kg/ton savings.
Fifty percent of the fluorine present in the emissions from
prebaked pots occurs as HF, while 90 percent of the fluorine
21
in Stud Soderberg pot emissions occur as HF . T"
18
7-19
-------
The gas flow rate for vertical stud Soderberg cells is 300
to 600 scfm per pot, while the flow rate for prebaked and hori-
zontal cells is 1800 to 3500 scfm per pot. The exhaust tempera-
tures of the gases from the electrolytic pots are approximately
22
1700 to 1800°F, while the velocity is between 25 and 50 fps.
This exhaust is mixed with ventilation air prior to gas treat-
22
ment. Table 7.14 gives the mass flow rate of exhaust gases
from cells, Soderberg or prebaked. Table 7.15 presents a summary
of aluminum smelter effluents.
Table 7.14 ESTIMATED COMPOSITION OF THE AIR DISCHARGED
FROM THE CELL ROOM BEFORE CONTROL EQUIPMENT12
Gas phase
Hydrogen fluoride
Sulfur dioxide
Carbon monoxide
Carbon dioxide
Dilution air
Total
Pounds per
hour
230
115
10,600
24,000
37,200,000
37,234,945b
Pounds per
ton aluminum
20.0
10.0
910.0
2,090.0
3,200,000.0
3,203,030.0
a) Expressed as pure fluorine.
b) Equivalent to an air flow of 7,700,000 scfm.
7.4.4 Finishing Operations
Casting and homogenizing - The pure aluminum deposited at the
bottom of the pot is siphoned into a holding ladle. The molten
metal is transferred into holding furnaces, then cast into billets,
slabs, or 'T1 shapes. The cast billet is passed through a homo-
7-20
-------
Table 7.15 ALUMINUM SMELTER EFFLUENTS MODELS
23
Component
Solid Fluorides
Quantity, Ib/Mlb Al
Loading, mg/in-*
HF
Quantity, Ib/Mlb Al
Loading, mg/ir,^
Total Fluoride2
Quantity, Ib/Mlb Al
Loading, ing/in-^
Alumina-'-
Quantity, Ib/Mlb Al
Loading, rag/m3
Total Solids
Quantity, Ib/Mlb Al
Loading, rng/m^
Sulfur Oxides
Quantity, Ib/Mlb Al
Loading, mg/nH
4
Diluent Air
106 cu. ft./Mlb Al
Collection Efficiency
Solid F, %1
HF , S
Total F, %
New Probake
Total
10
-
13
-
23
-
20
-
48
-
15-50
-
27.5
Prim.
9.5
61
12.6
81
22.1
142
19.0
122
46.1
295
14-48
90-300
2.5
95
97
96.0
Sec.
0.5
0.32
0.4
0.25
0.9
0.57
1.0
0.64
1.9
1.2
1-2
0.6-1.2
25
Old Prebake
Total
10
—
13
-
23
-
20
-
48
-
15-50
-
27.5
Prim.
8.0
51
11.7
75
19.7
126
16.0
103
41.3
265
14-45
90-300
2.5
80
90
85.6
Sec.
2.0
1.3
1.3
0.8
3.3
2.1
4.0
2.6
6.7
4.4
1-5
0.6-3.2
25
. VSS Soderberg
Total
3
—
20
-
23
-
3
-
39
-
15-50
-
35.5
Prim.
1.5
47
17.0
543
18.5
590
1.5
47
25.9
826
13-43
420-1380
0.5
50
85
80.4
Sec.
1.5
0.7
3.0
1.4
4.5
2.1
1.5
0.7
13.1
6.1
2-7
0.9-3.2
35
HSS Soderberg
Total
10
—
13
-
23
-
20
-
49
-
15-50
-
18.5
Prim.
8^0
37
11.7
53
19.7
90
16.0
73
38.2
174
14-45
64-206
3.5
80
90
85.6
Sec.
2.0
0.9
1.3
0.6
3.3
1.5
4.0
1.8
10.8
18.4
1-5
0.4-2.3
3.
1 Includes fugitive dusts from cell room.
2 Reported range 12.8 to 33.0 Ib/Mlb Al.
3 10 Ib SO, per 1000 Ib Al per percent S in anode coke.
4 Represents total cell room air.
-------
genizing furnace to improve metallurgical properties such as
grain structure and ductility.
Emissions from material handling are estimated to be about
10 pounds of particulate per ton of alumina produced. Particu^-
late from metal-casting operations contain A1C13, A1203 and
cryolite. Exhaust gases contain carbon dioxide and carbon mon-
12
oxide.
7.5 MAJOR POLLUTANT SOURCES
Reduction cells, calcination of alumina and material
handling operations are the major sources of pollutants.
0 Reduction cells - Of the three kinds of cells in use,
the horizontal-stud Soderberg cells have the highest emis-
sion rate.
The particulate emissions contain Al-O , A1F_, Na^CO-
and carbon dust. Nearly 60 percent of the particulate
present is in the size range of 1 to 5 microns. A sig-
nificant portion of particulate emission is fluoride. The
horizontal-stud Soderberg cell emits about 98.4 pounds of
particulate, 26.6 pounds of gaseous fluoride (HF) and 15.6
pounds of particulate fluorides (F) per ton of aluminum
produced. The vertical-stud Soderberg cell emits 78.4
pounds of particulate, 30.4 pounds of gaseous fluorides (HF)
and 10.6 pounds of particulate fluorides (F) per ton of
aluminum. The particulate emissions increase with increas-
ing temperature. The gas temperature is around 1750°F. Not
all industries have adequate control.
7-22
-------
REFERENCES FOR CHAPTER 7
1. Stamper, J.W., Aluminum, In: Minerals Year Book. Vol.
I. Bureau of Mines. 1971.
2. U. S. Bureau of Mines, Minerals Yearbook, 1970.
3. Air Pollution Control in the Primary Aluminum Industry.
Singmaster and Breyer. Metallurgical and Chemical Process
Engineers. Contract No. CPA 70-21. July 23, 1973.
4. Saeman, W. C. Alumina from Crystallized Aluminum Sulfate.
Journal of Metals, July, 1966.
5. Patterson, S. M. and Dyni, J. R. Aluminum and Bauxite,
U. S. Geological Survey, Professional Paper No. 820.
6. Engineering and Mining Journal, 1971.
7. Watson, T. L. Bauxite Deposits of Georgia, Geological
Carvey of Georgia, Bulletin No. 11.
8. Kirk-Othmer. Encyclopedia of Chemical Technology. New
York. John Wiley and Sons, Inc.
9. Hanna, T. Air Emissions from Primary Aluminum Industry.
Term paper. Air Resource Programme, Department of Civil
Engineering, University of Washington. Seattle, March 10,
1970.
10. Vandegrift, A. E., and others. Particulate Air Pollution
in the United States.
11. Rushing, J. C. Alumina Plant Tailings Storage. Metallurgical
Society of AIME, Chicago, Illinois, February 25-28, 1973.
12 Utilization of Red Mud Wastes for Light-Weight Structural
Products. IITRI Project No. G-6075, prepared for U. S.
Bureau of Mines.
13 Background Report In Support of Regulations and Standards
* for Primary Aluminum Plants. State of Washington. Depart-
ment of Ecology. April 1970.
14. Marshall, R. C. A Generalized Enforcement Report on
Aluminum Reduction Plants.
15. Mayers, David. New Techniques In Aluminum Production.
Chemical Engineering. June 5, 1967.
7-23
-------
-16. Ball, D. F. and P. R. Dawson. Air Pollution from
Aluminum Smelters. Chemical Process Engineering.,
52, 1971.
17. Engineering and Cost Effectiveness Study of Fluoride Emis-
sions Control. Volume 1, TRW Systems and Research Corp.,
Reston, Virginia; prepared for EPA, Office of Air Programs,
R.T.P., N.C., under Contract No. EMSD-71-14, January, 1972.
18. McCabe, Louis, C. Atmospheric Pollution. Industrial and
Engineering Chemistry 47(8). August 1955.
19- Sitting, M. Pollutant Removal Handbook. Noyes Data
Corporation. 1973.
20. Solntsev, S. S. Computational Method of Determining
Fluorine Balance During Aluminum Electrolysis. Text in
Russian. Tesvetn. Metal., 40(2). 1967.
21. Less, L. N. and J. Waddington. The Characterization of
Aluminum Reduction Cell Fume. AIME, New York, New York.
1971.
22. Exhaust Gases from Combustion and Industrial Processes,
Engineering Science, Incorporated, Washington, D. C.
October 2, 1971.
23- Dumont,Rush, J. C. Russell, Reid E. Iversen. Effectiveness
and Cost of Air Pollution Abatement on Primary Aluminum Pot
Lines. Presented at annual APCA Meeting, Miami, Florida,
June, 1972.
7-24
-------
8 . 0 TITANIUM INDUSTRY
8.1 INDUSTRY BACKGROUND
Titanium was discovered in 1790 by William Gregor, an
English clergyman and mineralogist. He determined that a
black magnetic sand (ilmenite) was a mineral of an unknown
metallic element which he named menaccanite, after his local
parish. Five years later the German chemist, Martin Klaproth,
found that a mineral in Hungary called rutile was the oxide
of a new metal, which he called titanium. A short time
later it was established that rutile and menaccanite were
minerals of the same metal. More than a hundred years later
titanium was first used commercially in the United States as
an additive in iron and steel manufacture. Ti° P-"-<3ments
were first available commercially in America in 1918; weld-
ing rod coatings have contained titanium since 1935.
The titanium industry has grown rapidly since about
1950, when the metal was first used in defense applications
Although titanium is relatively high-priced, it is never-
theless the most economical material for certain applica-
tions. Its low density, about 57 percent of that of steel,
can yield major weight savings and premium performance for
aircraft. It is also highly corrosion resistant. The
8-1
-------
demand for titanium compounds is greater than that for the
metal. Titanium dioxide is used extensively as a brilliant
white pigment.
The birth of the titanium industry can be traced to
Wilhelm J. Kroll; between 1932 and 1940 he produced a good
quality ductile metal by reducing titanium tetrachloride
with magnesium in a closed system. Around 1950, the U.S.
Bureau of Mines studied all known processes for producing
titanium metal and concluded that the Kroll process was the
most promising for producing ductile metal. The Bureau
constructed and operated a series of small reactors to study
the process and to demonstrate its feasibility. This study
was largely instrumental in establishing the domestic
titanium industry. With an increasing demand for large
quantities of metal in the defense program, the Office of
Defense Mobilization provided funds for titanium facilities
and the General Services Administration agreed to buy excess
metal at market or contract prices; as a result, excess
metal was stockpiled until around 1958.
Because of its high ratio of strength to weight, tita-
nium is used widely in the aerospace industry. In the
1950's less than 1 percent of the structural weight of large
aircraft was titanium. During the 1960's up to 3 percent of
the total structural weight of such aircraft was titanium.
Some supersonic aircraft constructed after 1965 have con-
tained over 90 percent titanium in structural members. The
8-2
-------
Boeing 747 commercial jet airliner requires 45 tons of
titanium mill products for engine components, fasteners, and
critical airframe parts.
The recent cancellation of the Boeing supersonic trans-
port (SST) program and reductions in military aircraft
production have caused a serious setback in the titanium
industry. In 1971 titanium ore production in the United
4
States dropped to the lowest level since 1959.
The two principally occurring titanium ores are rutile
and ilmenite, each with different end-use patterns. Ilmen-
ite is used mainly for making titanium pigments, whereas
rutile is used to make pigments and metal as well as other
products. The U.S. is a major source of ilmenite, but
produces practically no rutile and therefore must rely
almost entirely on foreign sources for ores from which to
product titanium metals. Production of ilmcnite concentrate
in the U.S. reached a high of 960,000 tons in 1968 but was
down to 714,000 tons in 1971. Ilmenite imports ranged from
111,000 tons in 1968 to 231,000 tons in 1971. Rutile con-
centrate imports ranged from 174,000 tons in 1968 to 243,000
tons in 1970. From 20 to 40 percent of our metallic tita-
nium requirements are imported in the form of sponge metal
every year. During the period from 1967 to 1971 the U.S.
consumed approximately 50 percent of worldwide rutile pro-
duction. In the same period, U.S. consumption of ilmenite
4
was approximately 27 percent of world production.
8-3
-------
The U.S. Government offers exploration assistance at 75
percent of the approved cost of exploration for rutile, but
2
no applications for assistance were submitted in 1971.
About 85 percent of the ilmenite produced in the U.S.
comes from two mines in New York and Florida. The remainder
is produced at four small mines in New Jersey, Virginia, and
Georgia. Ilmenite for the rest of the world comes mainly
from one mine in Canada, one in Norway, five in Australia,
and an unknown number in Russia. In 1968, domestic rutile
came from only one mine in Virginia, which ceased operation
during that year. Virtually all of the world's rutile
output is from about a dozen mines along the east coast of
Australia, several in the U.S.S.R. and one in Sierra Leone.
The titanium industry is characterized by a moderately
high degree of integration from raw materials to semi-
finished products. Several companies mine and utilize the
ore minerals in producing titanium pigments. The Titanium
Metals Corporation of America, owned jointly by National
Lead Company and Allegheny Ludlum Steel Corp., is fully
integrated from the mine to semi-finished titanium products.
The National Lead Company, with mines in the U.S. and Norway,
controls approximately 50 percent of the world's reserves of
ilmenite. Rutile reserves in Australia are controlled
chiefly by Consolidated Goldfields of South Africa Ltd.
Rutile reserves in Sierra Leone are owned 80 percent by PPG
Industries, Ind., and 20 percent by British Titan Products
Company, Ltd. National Lead and du Pont own or control 35
8-4
-------
percent of the world's productive capacity for titanium
.u 3
pigment.
In 1971, ilmenite concentrates were produced by du Pont
in Starke and Highland, Florida; by Humphreys Mining Company
in Folkston, Georgia; by SCM Corporation, Glidden-Durkee
Division, Lakehurst, New Jersey; by NL Industries, Inc.,
Tahawus, New York; and by American Cyanamid Co., Piney
River, Virginia. No domestic production of rutile con-
centrate was reported. The American Cyanamid Company closed
its mine at Piney River, Virginia, in June 1971. Titanium
Enterprises, a joint venture of American Cyanamid and Union
Camp, installed plant facilities and initiated mining in
1972 at its Green Cove Springs property in Florida. This
mine, located 35 miles inland from the ocean, is to produce
some 140,000 tons of concentrates per year. American
Smelting and Refining Company developed beach sand deposits
discovered in New Jersey in 1957, and the company concluded
a 10-year agreement with du Pont under which American Smelt-
ing will supply du Pont with up to 165,000 long tons of
ilmenite concentrate per year. The site is near Lakehurst,
New Jersey, and production at a rate of 20,000 tons of ore
per day started in April 1973. Kerr-McGee Corporation, a
major producer of titanium pigments, continued engineering
work to develop methods to process mineral deposits in
4
western Tennessee.
Titanium sponge metal was produced by three companies
in 1971:
8-5
-------
Titanium Metals Corporation of America, Henderson,
Nevada, owned by NL Industries, Inc., and Allegheny
Ludlum Steel Corp.
RMI Company, Ashtabula, Ohio, owned by National Dis-
tillers and Chemical Corp. and U.S. Steel Corp.
Oregon Metallurgical Corporation, Albany, Oregon,
partly owned by Armco Steel Corporation and Ladish
Company.4
Because of cancellation of the SST program and the
resultant poor demand for titanium metal during 1971, all
three companies shut down their sponge metal facilities
4
during that year.
Nine companies produced titanium ingots from sponge
metal and scrap in 1971:
Crucible Steel Company of America, Midland, Pennsylvania
Harvey Aluminum, Inc., Torrance, California
Howmet Corp., Whitehall, Michigan
Oregon Metallurgical Corp., Albany, Oregon
RMI Company, Ashtabula, Ohio
Teledyne Titanium, Inc., Monroe, North Carolina
Titanium Metals Corporation of American, Henderson,
Nevada
Titanium Technology Corp., Pomona, California
4
Titanium West, Inc., Reno, Nevada
These companies produce titanium pigments:
American Cyanamid Co., Piney River, Virginia, and
Savannah, Georgia
American Potash and Chemical Corp. - Kerr-McGee Corp.,
Hamilton, Mississippi
Cabot Titania Inc., subsidiary of Cabot Corp., Ashtabula
Ohio
8-6
-------
E.I. du Pont de Nemours and Co., Inc., Edge Morr,
Delaware, Antioch, California, and New Johnsville,
Tennessee
NL Industries Inc., St. Louis, Missouri
New Jersey Zinc Company, controlled by Gulf and Western
Industries, Gloucester, New Jersey
PPG Industries, Natrium, West Virginia
SCM Corporation, Glidden-Durkee Division, Baltimore,
Maryland
4
Sherwin-Williams Chemical Company, Ashtabula, Ohio
Industry and Process Trends
In 1971, consumption of ilmenite declined more than 7
percent. Consumption of rutile, however, which is used
principally for production of titanium dioxide pigment,
titanium metal, and welding rod coatings, increased by 21
percent. Since demand for titanium metals is closely tied
to the fortunes of the aerospace industry, the abandonment
of the SST project and the slow development of commercial
aviation programs created serious problems for titanium
suppliers. Table H-l in Appendix H gives data on consump-
tion of titanium concentrates in the United States.
Titanium demand for the year 2000 is expected to be
between 1.1 and 2.6 million tons. This would entail an
average annual growth rate of from 2.7 to 5.6 percent from
the year 1971. By the year 2000 anticipated domestic
requirements for titanium metal, from 106,000 to 390,000
tons, could comprise from 5 to 30 percent of total titanium
demand.
About 20 percent of the domestic demand for titanium
metal in 1968 was met by secondary sources. It is antic-
8-7
-------
ipated that by the year 2000, 40 percent of the domestic
3
requirement will be from secondary sources. In 1968,
approximately 150,000 tons of titanium in ilmenite was mined
from sand-type deposits in the United States. Water pol-
lution problems may prohibit any large-scale expansion of
output from some of these deposits, but it may be assumed
that the current rate of operation could be continued during
the forecast period at current cost levels. This situation
could result in the availability of 4.8 million tons of
titanium. Continuation of current levels of domestic oper-
ation in rock deposits would lead to availability during the
forecast period of an additional 5 million tons, also at
present cost levels. Alleviation of environmental problems
in mining sand deposits and the need for improved technology
for mining and processing titanium minerals from rock de-
posits will tend to increase the cost of any additional
domestic supplies of titanium during the forecast period.
Consumption will probably shift to the more abundant rock-
type deposits as the predominant source of titanium.
Ilmenite presently is the mineral source of 85 percent of
world titanium requirements. The known world supply of this
mineral at reasonable costs theoretically could meet the
cumulative world demand for titanium through the year 2000.
Resources of rutile are limited. If mining operations
are expanded to continue production of 15 percent of the
total requirement for titanium, world reserves will be
exhausted by the mid-1980's. The U.S. and the rest of the
8-8
-------
world have abundant resources of ilmenite. Under conditions
of increasing costs, estimated at 5 to 25 percent above 1968
prices, or improved technology, the U.S. could supply all
its needs for titanium indefinitely from domestic sources.3
Since enough rutile may not become available to meet
demands for TiCl. for pigments and metal, economic processes
need to be developed for chlorinating ilmenite or for making
a high-TiO2~content product that is suitable for chlorin-
ation or for use directly as a pigment. Economically
feasible methods to chlorinate titanium oxide are also
needed. If chlorination of ilmenite or other high-iron-
content materials are to become commercial, a use must be
found for the by-product iron chloride. Similarly, in the
production of TiO2 by the sulfate method only part of the
iron sulfate by-product is utilized and the remainder con-
stitutes an expansive waste and disposal problem.
8.2 RAW MATERIALS
Additional raw materials are generally not required for
beneficiation of titanium ores. Ilmenite is beneficiated by
classification and flotation methods along with magnetic and
electrostatic separators. Rutile sands are also classified
rather easily. Upgrading of hematite-ilmenite and mag-
netite-ilmenite ores requires crushing them with coal and
smelting them in an electric furnace to produce a component
mixture of molten iron and slag, which contains 70 to 90
percent TiO_.
8-9
-------
Considerable quantities of chlorine are required to
produce TiCl.. However, this chlorine is later liberated
when the TiCl. is converted back to TiO2. When titanium
metal is produced, the chlorine is converted to magnesium
chloride or sodium chloride. Some plants recover the re-
ductant metal and chlorine by electrolysis.
The most common titaniferous materials are anatase,
ilmenite, leucoxene, and rutile. In addition, a few de-
posits contain large amounts of less common materials.
Perovskite, Brookite, sphene, and magnetite also contain
titanium.
Anatase is brown, crystallizes in the tetragonal system,
and in the natural state contains 98.4 to 99.8 percent TiO2.
Ilmenite is iron black and crystallizes in the hex-
agonal system. Although it consists theoretically of 52.66
percent Ti02 and 47.34 percent FeO, at ordinary temperatures
it usually contains small amounts of magnesium and manganese
as well as Fe2O3.
Leucoxene is a fine-grained rutile or anatase, or
mixtures of these with amorphous material. This product
usually contains more than 68 percent TiO2 and occurs with
other titanium materials.
Rutile occurs as reddish-brown to red crystals of
tetragonal structure or in granular masses. It is essen-
tially pure TiO2, but some deposits contain large amounts of
ferric iron, tantalum, or columbium.
8-10
-------
Titanium slag may also be considered an ore. It is
produced by smelting a mixture of carbon and titanium-
bearing material to yield molten iron and slag containing
about 70 to 90 percent Ti02.
8.3 PRODUCTS
The various products of the titanium industry are
described briefly.
Titanium tetrachloride, TiCl4, is a volatile, colorless
liquid, an intermediate product used in the manufacture of
titanium metals and pigments.
Titanium metal is a low-density, silvery-white metal
important for its high strength-to-weight ratio and its
resistance to corrosion. It is 61 percent heavier than
aluminum but only 56 percent as heavy as alloy steel. The
strength-to-weight ratio below 1000°F exceeds that of
aluminum and of stainless steel.
Titanium dioxide pigment is sold domestically in three
grades. Rutile and anatase grades are fairly pure titanium
dioxide, but because of differences in crystal structure
they differ in hiding power and chalking characteristics.
Each is 95 to 99 percent pure Ti02- Extended titanium
pigment contains only 30 to 50 percent Ti02, as sold com-
aercially.
Titanium sponge is an elemental metal product with a
sponge-like appearance, obtained by reducing TiCl4 with
fflagnesium or sodium. It is remelted into solid titanium
ingots.
8-11
-------
Titanium ingots include three types, classified accord-
ing to the predominant crystal structure: alpha, alpha-beta,
and beta. Aluminum is the most prominent alpha-stabilizing
addition. Alpha-beta alloys contain some aluminum, but also
contain additional metals to stabilize the beta phase. The
beta alloys also have a mixed alpha-beta structure, but are
predominantly beta. About 20 commercial and semicommercial
titanium alloys are available to the titanium user.
8.4 PROCESS DESCRIPTION
As illustrated in Figure 8.1, titanium manufacturing
operations include mining, beneficiation, metal production
processes, and pigment production processes.
8.4.1 Mining
1*) Rutile - Rutile ores required for metallic titanium pro-
duction are generally not mined in the United States; there-
fore, mining contributions to air pollution, water pollution,
and solid wastes problems in the U.S. are minimal. Although
some ore is imported, a large portion of the titanium for
metal requirements is imported in the form of sponge metal.
(2) Ilmenite sands - Florida sands are mined by underwater
suction dredges. Surface preparation includes removal of
standing timber, stumps, and roots. Eight-inch-diameter
holes are then drilled at 20-foot intervals and loaded and
blasted. Removal is done with a suction cutterhead capable
of digging 1200 tons of solids per hour at a depth 45 feet
below the water surface. The slurry, consisting of 10 to 15
* Numbers refer to corresponding processes in Figure 8.1.
8-12
-------
METAL PRODUCTION
MIHNG
RUTILE
MINE
I J I I
Figure 8.1. Titanium industry.
-------
percent solids is pumped to barges, where the ore is ben-
eficiated, as described in Section 8.4.2. Since the ore is
wet-mined, atmospheric emissions are minimal. The large
dredging operation must be kept isolated from other water
bodies so that potential water pollution problems are not
intensified.
Ilnenite rock - Rock deposits in New York are mined by use
of electric shovels for loading and diesel trucks for haul-
ing the ore. The ore is drilled and blasted in 35-foot
bench heights. Approximately 1.2 tons of waste must be
removed to obtain 1 ton of ore, which averages 18 percent
TiO.,. Atmospheric emissions from this operation are probably
similar to those from other strip-mining activities. Both
the blasting and the minerals handling at the mine may
release significant quantities of fugitive dust. The over-
burden must be handled and stored properly to prevent the
-miner operation from becoming unsightly. Provisions should
be rr.ade for backfill and landscaping of the mine site after
the ere is extracted. Without such treatment, erosion may
lead to surface runoff, with associated water pollution
problems.
3.4.2 Beneficiation
Rutile ore - Rutile sands are fairly easily beneficiated to
vield a concentrate containing 90 to 98 percent Ti02. The
rutile ores are preferred for metal production because they
are less difficult to chlorinate than ilmenite ores and they
have fewer impurities that tend to carry over into the metal
8-14
-------
escalate proportionately. Environmental restrictions may
also preclude expansion of mine production.
Ores from rock deposits are crushed and ground in
several stages by jaw crushers, cone crushers, and rod mills
to produce a minus-28-mesh material. Wet magnetic sepa-
rators remove the magnetic fraction of the material. The
nonmagnetic fraction containing gangue and ilmenite is
sized; the ilmenite is then concentrated on reciprocating
tables, dried, and upgraded to a 45 percent TiO2 concentrate
on a dry magnetic separator. Wet processing results in a
large quantity of slime. Ilmenite values are recovered by
flotation. Eguipment for the operation includes thickeners,
dewatering rake classifiers, cyclone separators, and flota-
tion cells.
Considerable attention has been given to upgrading of
ilmenite ores for use as a substitute for rutile, which is
in rather short supply. These methods, which mainly entail
the removal of iron, are being considered by ilmenite pro-
ducers, rutile consumers, and the Federal government. Most
of the methods that have approached commercialization in-
volve an acid-leaching process that can cause serious water
pollution problems. Waste disposal problems considerably
limit the productive capacity of such plants. The processes
are not yet economical, and prices for upgraded ilmenite are
still slightly below those for natural rutile. Three
methods of upgrading ilmenite that are reported to cause
less significant waste disposal problems have been proposed:
8-16
-------
1) a U.S. Bureau of Mines pyrometallurgical process based on
producing titanium-rich slag and pig iron from ilmenite, 2)
a carbonyl process whose by-product, iron pentacarbonyl , can
be decomposed into iron powder and carbon monoxide, which is
recycled, and 3) the Murso process, which separates iron and
other impurities to yield a product containing about 95
percent TiO~ .
8.4.3 Smelting
- Smelting is done to upgrade certain ores con-
taining large quantities of iron with titanium. Titanium-
rich slag is recovered from the iron smelting process. The
slag is produced in Canada; there are no reports of its
being produced commercially in the United States.
Environmental problems resulting from this process are
expected to be typical of those involved in the melting
aspects of the iron-making industry. Proven technology is
available for the control of fumes from such melt processes.
Particulate emissions from blast furnaces are well con-
trolled to prevent plugging of the heat exchangers on those
furnaces. Slag quenching activities may result in emission
of hydrogen sulfide and other undesirable volatiles, and
water pollution from quenching may also be significant.
Ultimate disposal of the slag after it has been processed
constitutes a solid wastes problem.
8.4.4 Metal Production
Chlorination - Rutile ores are used almost exclusively in
the manufacture of metal because of the requirement for a
chlorinated titanium intermediate product. Ilmenite ores
fl-1 7
-------
cannot be chlorinated economically because large quantities
of chlorine are consumed by the iron in ilmenite. The iron
chloride thus formed has little or no market value and poses
other processing difficulties as well.
The rutile ores are chlorinated in either batch fur-
naces, in fluidized beds, or in molten salt. The fluidized-
bed method lends itself to continuous operation. Chlorin-
ation proceeds rapidly between 800 and 1000°C. The main
products are titanium tetrachloride and carbon monoxide,
with small amounts of carbon dioxide and phosgene. The
TiCl is purified to a clear colorless liquid by fractional
distillation or rectification. By adding small stoichio-
metric amounts of water, aluminum is precipitated as aluminum
oxychloride. Vanadium impurities can also be removed by
distillation. Alternatively the vanadium can be removed as a
sulfide by the addition of H2S.
Effluent gases resulting from the manufacture of TiCl4
have been reported to include 75 pounds C12, 25 pounds HC1,
and 23 pounds TiCl4 per ton of TiCl4 produced. These emis-
sions are controlled by water and caustic scrubbers. If the
scrubber effluent becomes acidified, the chlorine may be
released into the atmosphere. The waste metal chlorides can
release HC1 if they are exposed to moisture in air. These
wastes are usually buried in landfills or are hydrolyzed and
injected into deep wells. Alternatively, they are disposed
7
in impounding ponds or are dumped at sea.
8-18
-------
Increasing regulation of ocean dumping and land dis-
posal operations is of concern to processers. The chloride
disposal problem is generally considered to be considerably
less severe than the problem of disposal of sulfates and
acids from alternative processes. Technologies that will
eliminate formation of these chloride wastes are being
sought.
Reduction - Production of 1 pound of titanium sponge metal,
requires approximately 2.5 pounds of rutile, 5 pounds of
chlorine, 1.25 pounds of magnesium, 0.9 cubic feet of inert
gas, and about 0.3 pound of petroleum coke. If the magnesium
chloride is processed to recover its elemental constituents,
producing a pound of sponge metal requires only about 0.2
pound of magnesium and 1 pound of chlorine. Power require-
ments range from 6 to 15 kilowatt-hours per pound of sponge.
The higher demand includes power to recover reductant metal
and chlorine.
Nearly all the current production of titanium metal
involves reduction of titanium tetrachloride with magnesium
in a closed system by the Kroll process. Sometimes sodium
•is the reductant instead of magnesium. In the magnesium
process cleaned magnesium ingots are first placed in the
bottom of the reactor, a steel pot. The reactor is then
sealed, evacuated, back-filled with argon, and preheated to
about 700°C. Purified TiCl. is admitted at a controlled
rate to maintain the temperature between 850 and 900°C.
Spongy magnesium metal and liquid magnesium chloride are
8-19
-------
formed. The magnesium chloride is drained and recycled
through electrolytic cells to recover the magnesium and
chlorine. After the addition of titanium tetrachloride is
stopped, the reactor is heated to about 900°C to reduce all
the TiCl. completely. When the reactor has cooled, the
spongy mass is removed. Salt is removed from the sponge
after crushing by vacuum distillation at temperatures up to
925°C or by leaching in dilute hydrochloric acid and drying.
Vent streams from the reactor vessel contain TiCl. and
MgCl2 vapors and reduced titanium chlorides. The stream
must be controlled by scrubbers to prevent TiCl. from re-
acting with moisture to produce titanium hydrate fumes and
HC1. Conventional waste disposal techniques are employed
to handle impurities in the sponge that are stripped out by
distillation. Some of the material may be drummed and sold
to refiners of other materials, but most of the waste,
mainly in the form of metallic chlorides, is deposited in
p
landfills or dumped at sea. Landfill material is a poten-
tial ground water pollutant.
(9) Melting - Early attempts to induction-melt titanium proved
unsatisfactory because of excessive contamination of the
metal by crucible materials. The satisfactory solution of
the problem is attributed to W. J. Kroll, who also invented
the reduction process that bears his name. The main features
of the induction furnace are a water-cooled copper crucible,
a consumable electrode, and a vacuum system. The electrode
8-20
-------
is made from compacted blocks of sponge metal blended with
desired alloying elements. The furnace is well evacuated
before melting is started. Sometimes a partial pressure or
argon of helium is used. Typical melting currents run
between 500 and 1000 amperes per inch of electrode diameter,
at 40 to 60 volts DC. The ingots so formed are commonly
remelted to improve homogeneity and to reduce the gas con-
tent of the metal.
8.4.5 Pigment Production
Extraction - About half of U.S. production of titanium
pigment is from ilmenite ore concentrates. The titanium
content is extracted with sulfuric acid. Titanium sulfates
form in an exothermic reaction that sustains temperatures
between 125 and 200°C. Iron in solution is reduced by
adding iron filings. Ferrous sulfate precipitates upon
cooling of the solution and is filtered out. Then the
titanium sulfates are converted to metatitanic acid and
precipitated by the addition of water. The precipitate is
filtered and dried.
Particulate air pollutants from pigment production are
usually controlled by wet scrubbing techniques. Spent
sulfuric acid and iron sulfates are the principal waste
products of this operation. Until recentlyr one plant has
discharged acid and sulfates wastes into tidewater, relying
on natural forces to dispose the waste; that company now
plans to barge strong acid wastes to deep water for dis-
charge. The Ti02 producers claim that the minerals being
8-21
-------
dumped are naturally occurrring salts and acids and that no
current alternative technology for waste disposal is feasible.
One company, which reports that environmental problems are
well in hand, concentrates stronger portions of spent acid
by evaporation and returns the acid to the supplier for
recycling. Weaker acid portions are neutralized and diluted
before being released into nearby waters.
(11) Hydrolysis - Rutile may also be used to produce TiO2 pigment.
In one method, TiCl. is hydrolyzed to produce titanic acid
and hydrochloric acid. The titanic acid is then precipitated
and separated. Acid wastes may constitute a disposal
problem.
(12) Oxidation - The solid titanium acids produced by extraction
and hydrolysis are burned at 900 to 1000°C to form TiO_ and
£»
to remove residual chlorine and hydrochloric acid. The
chlorine is recovered and recycled. Incentive for product
recovery preclude any significant atmospheric emissions.
Purified TiCl. is burned directly in air or oxygen to
produce TiO_ and chlorine. The Ti02 forms as a fine smoke,
which is collected by baghouses, and the chlorine is also
collected and reused. The exothermic reaction is sustained
at about 1000°C. The collected TiO2 may be calcined at 500
to 600°C to remove residual chlorine. The Ti02 may also be
subjected to additional grinding and finishing processes to
meet particular specifications. Since scrubbers are used to
recover Cl- and HCl, pollutant emissions are expected to be
minimal.
8-22
-------
Table 8-1 presents a summary of titanium emissions data
for all major potential sources.
8.5 MAJOR POLLUTANT SOURCES
The reduction and extraction processes are the impor-
tant sources of pollution.
0 Reduction operations - Gaseous streams contain TiCl.
and MgCl_ vapors. A large amount of solid waste containing
^
metallic chlorides is also produced and either land filled
or dumped at sea.
0 Extraction - Water and solid waste as well as air
pollution is emitted from this unit. Spent sulfuric acid
and iron sulfates are principal waste contents. The pro-
ducers dump the waste in the sea. No current alternate
feasible method for waste disposal exists.
8-23
-------
Table 8-1 SOURCES AND ESTIMATES OF TITANIUM-CONTAINING EMISSIONS8
oo
I
fc . .* .N : .T» • n £.•::. ; .C *-\ ....
>pea pit Xir.irj?
3enef iclation
Open Pit
Dredsirat
2. METAL PROCESS TNG
Metal Ingots
Carbides
Alloys:
Tttantun-?a9e
rerrotitaniua
St-iel "roaucsior,
' ,. '
1 Parttcv.late
i=ls3ion "actor „
fVi/tor.) (X^/ku x l:.J)
C.: c.i
38 19
9.5 4.75
0 0
0 0
0 0
ISO 75
it-
Coce
(B)
'B)
(D)
CD)
CO
Pro-
duction
leve 1
1,350,000
152,000
303,000
-
-
.
5,672
(tons of
alloy)
:,590
(Ti(> :on-
sumed as
in steel
r« f •
!n
15
*
*
-
-
.
i5~
•*
Xeli-
abil-
Code
(A)
(3)
(B)
(0
C-)
T1C2
Sefore
Controls
30
2,890
1,460
0
0
0
200
31
istl-
Mted
level if
irnissicn
Control
0
90
90
.
.
_
40*,
-y.
After
Controls
(tons/yr)
30
289
146
0
0
c
j.20
7
A) Excellent
B) Above Average
C) Average
D) Below Average
-------
8
Table 8-1 (Continued). SOURCES AND ESTIMATES OP TITANIUM-CONTAINING EMISSIONS
oo
l
N>
Ul
'
-v-..rr ,,-,v_ . T ,-cr;
'.•' o l^i;v Koc . ca- iru
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1
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4. "-:—"/ :-::•"—::•::
-
•sir.ts, etc.
"tr.tr V = c-
^: "-.rv-.r..
Co.-.'. C> *r,;:;.
r.ror.trolled
Tart ic. late
r.zissior. -'acur
(I: /'.or.} ('•;''''•••? x l:'
_ - 1
0 <-•
It I-
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' i •'• ' '•
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'•:)
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level
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t
• 10-
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—
- e li-
ar il-
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,' "= ',
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Bef ore
Controls
V
3
->- ^~,:T
US
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-?;.::;
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Control
"
67'
cont rols
per.tral ly
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97"
°9. 5
i"
-^:
•r
710;
i;E;:ss ions
After
Controls
(tons XT')
0
,1 1
|
;
-------
Table 8-1 (continued). SOURCES AND ESTIMATES OF TITANIUM-CONTAINING EMISSIONS8
00
I
to
en
i. •.: ;..r::.r^
•es . . .a.
". 1st •. IlatcS
s ;:on :• .cillic
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. ^ • . - . .".-r j
1
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(tor-t/vr)
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6,900,000
.con-
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-j
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o
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''tons-'vr1'
:o
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3 . 30r
i..
., ,=, i
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^y. > "-at A;?li;a'.-U
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* r.-.-isiiiir. r'actor aiileipli^r
-------
REFERENCES FOR CHAPTER 8
Kirk-Othmer. Encyclopedia of Chemical Technology, New
York. Wiley and Sons, Inc., 1966.
Stamper, John W. Titanium, In: Minerals Year Book.
Vol. I. Bureau of Mines, 1967.
Stamper, John W. Titanium, In: Minerals Year Book.
Vol. I. Bureau of Mines, 1970.
Noe, Frank E., Titanium, In: Minerals Year Book. Vol.
I. Bureau of Mines, 1971.
Titanium, A Materials Survey, 1957.
lammartino, Nicholas R. Troubled Times for TiO2-
Control Techniques for Chlorine and Hydrogen Chloride
Emissions - Draft Copy, Environmental Protection
Agency, March 1971, unpublished.
Report of Proposal for Liquid and Gaseous Waste Treat-
ment for Integrated Titanium Facilities - Oregon
Metallurgical Corporation, Albany, Oregon, August 11,
1969.
8-27
-------
9.0 URANIUM INDUSTRY
9.1 INDUSTRY BACKGROUND
Before the discovery of fission in 1939, few uses for
uranium were known, even though the element was discovered
in 1789 and isolated in 1841. Uranium ores were initially
sought primarily for their radium content, with most of the
uranium content being dispersed and wasted. Early attempts
to find markets for the material were largely unsuccessful.
The ceramic industry used uranium compounds as yellow and
green pigments. Manufacturers of tool steel alloys also
used some uranium. A limited amount of uranium-bearing ores
was stockpiled in hopes that a market would develop.
In 1939, L. Meitner and O. R. Frisch described the
fission phenomenon and suggested that a chain reaction could
be thus initiated. The atomic age accelerated quickly from
that point and climaxed in 1945 with the bombings of Hiroshima
and Nagasaki.
From the birth of atomic energy until 1966 the uranium
industry was completely dominated by the Federal Government,
and virtually all uranium mined was channeled into the
production of nuclear weapons.
As the nuclear electric power industry began to grow
in the late 1960's, the bulk of uranium usage shifted from
9-1
-------
the Federal Government to private industry. By 1968» about
98 percent of the uranium supply to industry was used to
generate electric power.
Other applications include the use of uranium oxides by
the chemical industry and of uranium metal for ballast
material by the aircraft industry. It is anticipated that
in the future nuclear reactors will be used on a large scale
for the desalting of sea water.
The United States produces about half of the free
4
world's uranium output. In 1971 U.S. production totaled
10,900 short tons of uranium (12,907 short tons of U30g).
The recoverable uranium oxide concentration in U.S. ore is
about 0.205 percent. Thus the U.S. produced approximately
6.3 million tons of uranium ore in 1971.
About 70 percent of current uranium ore production in
the U.S. is from the Colorado Plateau area located in Utah,
Colorado, Arizona, and New Mexico. Ore from this area
accounted for 73 percent of the uranium production in 1970.
The Wyoming Basin area provided 25 percent of the total U.S.
uranium ore and 23 percent of the total U.S. uranium pro-
duction. Other states producing uranium include North
Dakota, South Dakota, and Texas, accounting for about 4
4
percent of total U.S. uranium production in 1967.
Approximately 600 mining operations were active in
1966. In 1967 only 500 were operating, and in 1971 only
240. This high percentage of mine shutdowns resulted from
expiration of AEC uranium contracts in 1966. Although many
9-2
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mining companies anticipated a period of uranium oversupply,
the rate of increased demand for uranium to supply nuclear
electric power has exceeded the estimates of many experts.
Those mining companies that have continued to explore and
develop new locations have good profit potential. In 1968
uranium sold for $9.43 per pound. In 1971 the price had
fallen to about $7.00 per pound. It is estimated that by
the turn of the century the market value will exceed $20 per
2
pound (constant 1968 dollars).
The uranium industry of the United States consists of
many privately owned firms dealing in exploration, drilling,
mining, sampling, milling, and processing. In 1968 the only
Government-operated function in the nuclear fuel manufacturing
process was enrichment, performed at three Government-owned
gaseous diffusion plants located at Oak Ridge, Tennessee;
Paducah, Kentucky; and Portsmouth, Ohio. Distribution of
uranium milling activities in 1971 is shown in Table 9.1.
Table 9.1 U.S. URANIUM MILLING COMPANIES
AND PLANTS IN 19714
Hi., A In MI: MUM,, 1.1 I
.Sij-i\i,.| ulin.i \\Vsl ITU I
II .
I'll'.,11 ( .ul.i.d- , ',
i),.
Do
riliti',1 N'llrl.-ur (
I'tji. li.li-m.ili.,,i:il In,'
n,
\V,.,t«.rn Nta-Uar Ii,,-
<\ mf/any . I'liiiil location
llhirwiillT N. Mcx - - -
Miuli, I'lah
•i.iniMT Niii-li-ar. Iw -. Karnus C.rjnty, T«x
. <';.»,,n City, C.,1,, . . ... .
. 1-W.I, Wash
,. Amern-an Nliflear C.ir|> <',as Hills, Wyi)
,,^ i',, . . }',<*. l<;r Hivfr HUMM, Wyu . _
tyrants, N. Mrx
„,- K.ltfeim.nt, S. Dak ....
. Sliirl.-y Basin, Wye, .
l.a Sill, I'tah ... . ..
In.. . . Kails City. T.-x
Kay f'uint , Tf x . . .
Travail. C, ,!,,.'
N'alruna <'ounty, Wyo
In,- ifi.im-st.ilvp MlriinK Co (irants, N. Mt'X,,
. <;ns Hills, Wyo
.Shirley Ha.siii, \Vyii .... .
Jr/Ircy City, Wyo .
Caparity
(tons ,:( ore.
|»T .lay)
11, 01)11
1 . MM)
' 1,7T>0
4 r,0
. .. . r,ii(i
. . . . N.'iO
. ... i a. mill
. . 7.0(1 1
i;r. i
. l . r,d i
1 r,' 1 1
1.IKI)
10)0
'2JIKI
1 . " JO
:\ T) id
liiio
. . . . , i . -' >o
. . . . . 1. ••!(>»
i" . ,n,,i ru.ti.-r,. |i!:iiin.\ .
.-: I'.S. At.in.ii- KII.TK':, <'
9-3
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There were 240 uranium-producing properties in 1971.
One hundred ninety-three underground mines accounted for
45.3 percent of total mine output, and 29 open-pit mines
produced 53.3 percent. Miscellaneous activities produced
4
the remaining 1.4 percent. Ore shipments totaled 6,370,726
tons in 1971.
In 1967 Allied Chemical Corp., Metropolis, Illinois,
owned the only commercial plant for converting U_OQ into
J O
gaseous uranium hexafluoride, UF,, the compound required by
gaseous diffusion plants for producing uranium enriched in
235
U . The plant, closed in 1964, was maintained in a state
of readiness; and in 1967 Allied began construction to
double the size of the plant to an ultimate capacity in 1969
of 10,000 tons of tUO- per year. Kerr-McGee Corp. also
initiated plans for a UF, conversion plant to be ready by
1970 with a capacity of 5000 to 10,000 tons of U3Og annually.
Both General Electric Co. and Westinghouse Corp. operated
plants for fabricating nuclear fuel elements ari announced
plans for new ones. General Electric operates its facility
at San Jose, California, and started construction on a new
plant on a 1600 acre site near Wilmington, North Carolina.
Westinghouse fabricates fuel elements at its plant at
Cheswick, Pennsylvania, and was doubling capacity there. In
addition, Westinghouse broke ground for a new $20 million
facility at Columbia, South Carolina, planned for operation
in 1969. Aerojet and Gulf also produce fuel elements. Both
companies stated that the large volume of new orders for
9-4
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nuclear plants had strained the capacities of their fabri-
cation facilities.
Based on alternative future contingency requirements
for uranium, annual U.S. civilian demand in the year 2000 is
expected to range between 61,000 and 69,000 short tons of
uranium (72,000 to 81,100 short tons of U_00).2 This rate
J O
corresponds to a demand compound growth rate of 10.2 to 10.6
percent in the period 1968-2000. The annual demand for
uranium is expected to grow at average rates exceeding 25
percent until the mid-19801s. Demand is expected to peak
soon after 1990 and then to decline slightly for the re-
mainder of the century.
This forecast is discussed in detail in reference 2.
Virtually all of the forecast demand is for use in nuclear
electric power plants. But as much as 3 percent is allo-
cated for other miscellaneous purposes.
Cumulative demand for this period is expected to range
between 1.2 and 1.6 million short tons of uranium. As of
1969, reasonable assured reserves at $10 per pound of U^O0 or
3 8
less ($11.76 per pound of uranium) totaled about 204,000
short tons. Another 100,000 short tons is expected to be
made available as by-product leaching process. Thus,
proven reserves total only 20 to 25 percent of requirements
for the century. Massive exploration and development efforts
will be required if future demands are to be met. Emerging
technology may make it possible to mine certain low-quality
deposits economically.
9-5
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Uranium is not especially rare. The earth's crust
contains about 40 times as much uranium as silver and about
1/10 as much uranium as copper. Its abundance approximately
equals that of lead. Deposits of uranium with concentrations
high enough to be of commercial value are uncommon, however,
with rising demand for uranium, it will become more eco-
nomical to process lower-grade ores, thus increasing avail-
able reserves. One estimate indicates that 1.3 million tons
are available domestically at a price of about $25 per pound
(1968 dollars).
As of 1970 an embargo was placed on uranium imports to
ensure that the industry could survive during the adjustment
from a munitions market to an electric power generation
market. Thus, imports may in the future provide for some
U.S. uranium requirements, but competing world markets may
limit this supply significantly. Approximately 35 percent
of known free-world uranium reserves are in the United
States. Canadian ores account for 28 percent, and South
African ores account for 11 percent of the known supply.
Demand projections are based on current nuclear power
plant technology, by which reactors convert only about 1
percent of the energy in natural uranium. It is predicted
that new types of commercial breeder reactors will utilize
2
50 to 80 percent of the available energy. Such a break-
through would strengthen uranium resources so that they
would dwarf conventional fuel resources by a large margin.
9-6
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9.2 RAW MATERIALS
Uranium milling operations require large amounts of
sulfuric acid or sodium carbonate for leaching, as well as
Fe , MnO~, NaC10_ as an oxidizing agent and NaOH as an
alkali. Extraction solvents such as dialkylphosphoric acid,
dodecylphosphoric acid, and tributylphosphate are used with
a kerosene carrier in the solvent extraction process.
Various alkali anion-exchange resins are used in conjunction
with nitrate or chloride elutriants in ion-exchange processes
In the purification process, HNO_ is used to dissolve the
yellow cake, and organic solvents such as tributylphosphate
in a hexene carrier are used for solvent extraction and
purification. Hydrogen for the reduction of UO_ to UO» is
usually obtained by cracking ammonia. Hydrogen fluoride is
used to react directly with UO2 to form UF4. It is also
electrolyzed to obtain F2> which reacts with UF, to form
OF,. UF. can also be reacted with magnesium in a closed
b 4
bomb to form uranium metal. After the enrichment process,
UF, is reacted with NH.OH to produce ammonium diuranate
which is in turn made into UO2 for pelletizing.
0 Basic Types of Ores - Uranium occurs in a variety of
ores in quantities of economic importance. The principal
ores are listed below:
Uraninite - Most common ores contain UO2 and UO^. The
massive form is called pitchblende and is often con-
centrated in pegmatites and primary vein deposits.
Coffinite - A uranium silicate ore found in western
states.
9-7
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Carnotite - K2<3-2UO3«U2O5-n H2O is the most important
secondary uranium ore mined.
Multiple Complex Oxides Rare Earth Oxides with Columbium
and/or Tantalium -
Thorianite (Uranothorianite (ThU)O2; Fergusonite -
Formanite; Samarskite - Yttrotantalite; Euxenite -
Polycrase;
Some western lignites have been profitably ashed to
yield up to 0.5 percent U-,00.
J O
Some phosphate deposits contain uranium in quantities
great enough for profitable by-product recovery from the
production of phosphoric acid.
Primary Uranium Minerals:
Uraninite or pitchblende - Uranium dioxide
UO2; U = 46.5 to 88.2 percent
Betafite - Oxide of columbium, titanium, and uranium
(U, Ca) (C. , Ta, Ti) OQ-NH»O?; U = 13.7 to 24.5
percent D J y ^
Brannerite - Oxide of uranium and titanium with rare
earths
(U, Ca, Fe, Y, TbK (TiSi)5O16?; U = 27.9 to 43.6
percent
Davidite - a rare-earth iron-titanium oxide
A B^(O OH)_ or AB-O_ ,
A = Fe+2, rare earths, U , Ca, Zn, Ta
B = Ti, Fe+3, V, Cn; U = 0 to 4.4 percent
Euxenite - A rare-earth columbate-tantalate
(Y, Ca, Ce, U, Th)(Cb, Ta, Ti)2 Og; U = 0.6 - 8.0
percent
Fergusonite
(Y, Er, Ce, Fe)(Cb, Ta, Ti)O.; U = 0.8 to 7.2 percent
Samarskite
(Y, Ce, U, Ca, Fe, Pb, Ta)(Cb, Ta, Ti, Sn)2 Og;
U 8.4 to 16.1 percent
9-8
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Secondary Uranium Minerals:
Carnotite - potassium-uranium vanadate;
K2(UO2)2(^04)2 * 3H2°'
U = 52.8 to 55.9 percent
Tyuyamunite - calcium-uranium vanadate;
CA(UOo)2(VO4)2•7-10.5H2O;
U = 54.4 to 56.7 percent
Metatyuyamunite - calcium-uranium vanadate;
Ca(U02)2(V04)£•57H2O
U = 50.1 to 52.2 percent
Autunite - calcium-uranium phosphate;
Ca(U02)2(PO4)2-10-12H2O;
U = 45.4 to 48.2 percent.
Torbernite - copper-uranium phosphate;
CU(U02)2(P04)2-12H20;
U = 47.1 percent
Metatorbernite - copper-uranium phosphate;
audio?) 2(PO4)2*nH2On=4 to 8;
U = 50.8 percent
Gummite - chiefly uranium oxide with water and lead;
generic term for minerals occurring as alteration
products of uraninite and not otherwise identified.
Uranophane - calcium-uranium silicate;
Ca(UOo)2(SiO3)2•5H2O;
U = 55.6 percent
Schroeckingerite - water-rich carbonate and sulfate
containing uranium;
NaCa3(U02)(CO3)3(SO4)F-10H2O;
U = 26.8 percent
Coffinite - a uranium silicate;
U(Si04)1_x(OH)4x;
U = 60.2 percent in concentrated, but not pure sample
Zippeite - a uranium sulfite;
3UO3-2SO3-9H2O? or 2UO3-SO3.5H2O?;
U = 59.1 or 64.1 percent (?)
9.3 PRODUCTS
Uranium is used principally to fuel nuclear reactors
that produce electrical power. The fuel is in the form of
9-9
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uranium oxide pellets. A very small quantity of uranium is
used for research, military and space applications, isotopic
medicine, and the Plowshare program. The metallic form of
depleted uranium is used to some extent for ballast and for
radiation shielding. The metal is also used by the chemical
industry as a catalyst.
9.4 PROCESS DESCRIPTION
Figure 9.1 illustrates the processes in the uranium
industry.
9.4.1 Mining
(1*) Shallow mines - Some uranium mines contain less than 2000
tons of ore in shallow irregular deposits that cannot be
mined economically at depth. Fairly continuous production
from these mines can be attained only by continuous ex-
ploration and development. These mines are typical in the
Uravan mineral belt of Colorado. Mining methods vary some-
what because of the variety and irregularity of the de-
posits. Some mines require no more equipment than a pick, a
shovel, and a wheelbarrow. Others are large enough for
motorized rail equipment. The mine operator follows the ore
by monitoring the working face with a geiger counter.
Because of high ratios of waste to ore, the relative costs
of labor and explosives also are high. Production per man
shift averages only 2 or 3 tons of ore.
Free silica concentrations in uranium mines can be a
health hazard. Nearly all U.S. uranium ores contain 35 to
70 percent free silica. Exposure of workers can be controlled
* Numbers refer to corresponding processes on Figure 9.1.
9-10
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r
i r
i i
i
.J L.
. J
Figure 9.1. Uranium industry.
-------
by use of wet drilling methods, by requiring the use of
respirators, and by providing suitable ventilation at the
mine face. In dieselized mines the U.S. Bureau of Mines
recommends that 100 to 200 cubic feet of fresh air per
minute be provided per brake horsepower. This ventilation
rate is reported to be adequate to remove diesel exhaust
fumes and to reduce radon gas concentrations to below
acceptable limits if precautions are taken to ensure that
the vented fresh air reaches the vicinity of the working
face of the mine.
Although the exhaust air may carry with it particulate
matter, uranium mining "has not been found to cause measur-
able increases in environmental radioactivity outside the
immediate vicinity of the mines." Wet drilling creates the
hazard of water pollution, principally by particulates and
radioactive materials. Dry mining operations may create a
localized dust nuisance, with associated worker exposure
hazards described in the preceding paragraph.
(2 ) Underground mines - Large underground mines have been
developed in Utah and New Mexico. These deposits may be
very large, with deposits ranging from 5 to 20 feet thick
and 300 to 7000 feet wide. Depths of cover range from 100
to 700 feet. Various mining methods are used, including
room and pillar, longwall retreat, and panel mining. Mobile
equipment may be tracked or trackless. One mine in New
Mexico requires removal of about 500 gallons of water per
minute, and the mine is ventilated at a rate of 25,000 cubic
9-12
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feet per minute. Environmental problems are the'"same as
those with shallow mines.
Open-pit mines - More than half of the uranium in the United
States is mined by open-pit methods. In these mines,
virtually complete extraction of the ore is possible, but
the ore obtained is frequently of lower grade than that from
other types of mines. Stripping ratios (overburden to ore)
may be as high as 30:1, and overburden depth may range to
300 feet. Generally the ore must be drilled and blasted
loose, but the overburden can usually be removed easily.
The mines are large and fully mechanized, with large earth-
moving machinery. Fugitive dust emissions from these mining
operations may be significant. Other problems include
increased erosion, contaminated run-off water, and over-
burden disposal. Ore is usually transferred from the mines
in large trucks, but some mines are equipped with rail
facilities.6 Trucking operations in remote areas generate
considerable quantities of dust, especially where roads are
unpaved or poorly paved. Windblown ore losses from the
trucks also occur.
Preconcentration - Preconcentration of uranium ore is
difficult without sacrificing valuable products in the
tailings. As of 1969 no plants were operating in the U.S.
with preconcentrator units, but electronic ore-sorting
devices were used in earlier years.
Because the sizing and sorting operations in precon-
centration generate some dust, mine operators should apply
appropriate dust control systems as necessary.
9-13
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(5 ) Ore sampling - Ore shipments are sampled and analyzed to
determine moisture and uranium contents before they are sent
to the mills. Mechanical sampling plants constructed near
the mining areas for that purpose consist mainly of a three-
or four-stage crushing and sample-splitting facilities.
Dust from these operations is usually controlled with baghouse
collectors, typically with capacity of about 15,000 cfm at
an air/cloth ratio of 3 feet per minute. Workers in sampl-
ing plants are required to wear respirators in dusty
areas.6 Ore is transferred by truck or train from the
mining to the milling facilities. Windblown ore losses and
road dust resulting from transport of the ore both consti-
tute fugitive dust problems, mitigated somewhat by the
remote locations of the mines and mills.
9.4.2 Milling
After the ore is analyzed, it is processed (milled) to
extract the uranium and to concentrate it in the form of
yellow cake, a material rich in uranium oxide (U3Og).
Impurities in the yellow cake can total as much as 25 per-
cent. Several processing steps are entailed in the milling
operation, but a given uranium mill does not necessarily use
all of them.
(6 ) Crushing and grinding - Sand grains in uranium ore are
essentially barren, but the cement that binds the grains
together is rich in uranium. The ore must therefore be
crushed to the size of the sand grains for release of the
uranium by leaching. Crushing is accomplished in several
9-14
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stages, since ore is transferred from the mines in lumps as
large as 12 inches diameter. Coarse crushing is performed
in jaw crushers. Fine crushing may utilize smaller jaw
crushers, gyrators, hammer mills, rod mills, and ball mills.
The degree of required grinding varies with the deposits.
In some western ores the uranium minerals are not signif-
icantly locked within insoluble materials, and extraction
from 10-mesh particles is essentially complete. Processing
of other ores requires much finer grinds. Grinding to 50
percent minus-200 mesh is fairly typical. These crushing
and grinding units release particulate matter into the air
and often require some degree of dust control.
Roasting - Roasting at 500 to 600°C may enhance the ex-
traction of vanadium from vanadium-rich uranium ores, but
roasting is not required for most uranium ores. Sometimes
carbonaceous material must be burned from ores containing
shale, lignite, and asphalt. Roasting also improves the
settling and filtering characteristics of ores containing
clay minerals. Atmospheric emissions, varying with the
material being driven off, may include carbonaceous mate-
rial, particulates, hydrocarbons, and sulfur compounds.
Acid leaching - After the ore is ground and roasted (op-
tional) , the uranium content is leached, usually in mechan-
ically or air-agitated tanks containing sulfuric acid or a
carbonate solution. Sulfuric acid is used unless acid
consumption by the particular ore exceeds about 150 pounds
per ton of ore. Capital costs for acid leaching circuits
9-15
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are generally lower than for carbonate circuits, principally
because the carbonate circuits require the use of auto-
claving equipment. However, corrosion problems are more
severe in an acid circuit. Acid circuits are easier to
control and yield higher recoveries - yields above 98 per-
cent are not uncommon. To obtain high efficiency the
uranium must be oxidized from U to U , generally accom-
plished by the use of MnO2 or NaClO.,. Ferric iron in
solution is also needed for oxidation. Usually sufficient
iron is present in the ore. The dissolved iron is air
oxidized to the ferric ion by virtue of air agitation.
Leaching by aqueous agitation is performed at densities
between 40 and 65 percent solids. Mechanical agitation with
turbine impellers in baffled tanks is widely used in the
United States. Continuous rather than batch leaching is
practiced almost exclusively in the U.S., with 4 to
14 tanks in series. High temperatures and pressures
may be required. One Canadian plant leaches at 107 to
122°F for 48 hours. Acid leaching creates large amounts of
solid and liquid wastes. Undissolved materials must be
disposed of, and care must be taken not to contaminate water
supplies with liquid or solid wastes. Steps must also be
taken to prevent escape of acid mists into the atmosphere.
(9) Carbonate leaching - Carbonate leaching is used to treat
ores with high lime content that would cause excessive acid
consumption. With proper oxidizing conditions, yields range
between 90 and 95 percent. Ores usually must be ground
9-16
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somewhat finer than for acid leaching because the carbonate
does not react with material surrounding the uranium mineral.
Leaching is slow, when done at atmospheric temperature and
pressure. Autoclaves are used frequently. Uranium is
precipitated from the carbonate solution with sodium hy-
droxide .
9.4.3 Extraction Process
After the uranium has had time to dissolve, the liquid
portion of the slurry (pregnant liquor) is separated from
the solids. Flocculants used to accelerate the thickening
and filtering of the ore from the liquor include various
vegetable gums, cactus extract, high glue, polyacrylamides,
and starch. Also, several synthetic polymer flocculants
have been developed.
Solvent extraction - The uranium salts are usually separated
from the leach liquor with alkylamines and organophosphorus
compounds. By changing process conditions the uranium
salts can be partitioned from the leach liquor into an
organic phase. Then the uraniferous material is re-par-
titioned into an aqueous solution, from which it is pre-
cipitated as "yellow cake." The various liquid discharges
are potential water pollutants since the liquids may contain
dissolved and suspended solids, organic materials, and
radioactive wastes.
Ion-exchange - The ion-exchange uranium extraction process
is widely used, although it has been replaced by solvent
extraction in several plants. Adsorbent systems usually
9-17
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incorporate strongly basic anion-exchange resins with quat-
ernary ammonium bases that extract uranium in the form of
anionic complexes. The batch process involves sorption,
washing, elution, and regeneration. Automated valving
equipment has reduced manual operations to the extent that
the overall procedure is like a continuous process. A
residence time of 7 minutes is adequate for adsorption.
After adsorption the uranium is eluted from the resin by
acidified nitrate or chloride solutions. The eluting
solutions are recycled. After the uranium is eluted from
the resin, the resin is flushed with fresh water to activate
it for the adsorption step of the next batch of pregnant
liquor. Waste water from this process contains acids and
nitrates or chlorides. The waste stream must be carefully
monitored if it is to be discharged into any body of water.
(12) Resin-in-pulp - Some uranium ores do not filter well after
leaching and do not lend themselves to conventional ion-
exchange equipment. For these ores the ion-exchange process
has been modified to extract the uranium directly from the
leach pulp. This modification is called the "resin-in-pulp"
(RIP) process. Environmental hazards are similar to those
from the conventional ion-exchange process.
9.4.4 Refining Operation
(13) Purification - Yellow cake concentrates are shipped in steel
drums to refining plants, where the concentrates are di-
gested in nitric acid for purification. Tributylphosphate
in kerosine or hexone may also be used in the extraction
9-18
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process, which yields purified UO.,. Atmospheric emissions
from this process are probably slight, consisting mainly of
solvent losses from exhaust ventilation. Water pollution
may result from discharge of the spent acid or organic
solvents. The impurities separated from the yellow cake are
reduced to a sludge, which is landfilled. Precautions must
be taken to ensure that groundwater contamination does not
result.
;|) Reduction - Reduction of UO, to U02 is accomplished by
cracking ammonia and reacting the H2 with the UO^ as follows:
H2(g) + U03(s) U02(s) + H20(g)
This process is either a batch or a continuous system; the
excess hydrogen is burned or recycled, and the dust is
collected and recycled. Operating temperatures range from
1500 to 1800°F. A hydrogen atmosphere is maintained until
the U02 is cooled, to prevent oxidation and formation of
U-00. Reduction is essentially a closed process, but some
J O
dust and gaseous products from impurities in the reaction
o
may be emitted. The inherent economic value of the uranium
virtually precludes any significant releases of uranium
products to the environment.
!5| Fluorination - Fluorination of U0« to obtain UF, is a two-
2 O
step process. First the UO_ is reacted with anhydrous HF,
which has been preheated to 550°C. The product of this
reaction, UF. or "green salt," is reacted with fluorine
produced at the refinery in electrolytic cells. The UF&
thus produced is purified and placed in cylinders. Pollu-
9-19
-------
tants may be vented from any of these processes, especially
from the electrolytic cells, which produce F2 from HF and
discharged with H» into the air. The UF, must be prevented
from contacting moisture because it hydrolyzes rapidly with
moisture to form UO2 and hydrogen fluoride.
(16) Reduction - If uranium metal is the desired product of the
refining process uranium tetrafluoride is mixed with mag-
nesium and a reduction reaction in a thermite bomb yields
metallic uranium. The reaction takes place at about 1900°C,
and the uranium is later remelted under vacuum conditions
and cast for fuel-rod fabrication or other end use. Al-
though the metal oxide slag from this process may be a solid
waste problem, the slag is used to line the reaction vessels.
Also, the uranium content is recovered from any excess slag.
Since this operation occurs in a sealed vessel, probability
of hazardous discharge is minimal.
9.4.5 Enrichment
(17) Diffusion - Enrichment by diffusion depends on isotopic
O O [T 2 "3 ft
differences. UFg is lighter than UFg, and therefore
diffuses faster through a porous membrane. Because the
diffusion rates are only slightly different, a great many
membranes are required for significant enrichment. Also,
extremely large amounts of electrical energy are required to
move the gas through the membranes. This process entails
little chance of pollution. The depleted UFg is put back
into cylinders for "permanent" storage, pending a market for
the material.
9-20
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5) Centrifugal separation - An experimental technique, centri-
fugal separation also exploits differences in atomic weight
to separate 235U from 38U. Again, the procedure holds
little chance for pollution, and problems of disposing of
the expended material are identical to those for diffusion
plants.
15) Electromagnetic separation - In this process a stream of
ionized UF, is passed near a magnetic field. Because the
b
lighter isotope is reflected slightly more than the heavier
one, a separation can be made. This process is too expensive
to be used commercially. Little potential for pollution is
foreseen.
9.4.6 Fuel Pellet Manufacturing
235
1} Conversion - Enriched uranium hexafluoride (up to 50% U)
is transferred to fuel pelletizing facilities in cylinders.
It is vaporized and converted to ammonium diurinate, which
in turn is dried, reduced in a rotary calciner, and con-
verted to UO0. The UO9 is ground to uniform particle size
^ ^
for pelletizing. As in any closed system, there is little
likelihood of environmental contamination.
'•!} Pelletizing - The powdered UO2 is measured into hydraulic
process and shaped into cylinders about an inch long and
half an inch in diameter.1 These cylinders are baked in a
sintering furnace and later ground to a slight hour-glass
shape. Particulate emissions from the grinding process are
collected and recycled. Pollutant emissions and fuel com-
bustion emissions are minimal.
9-21
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9.4.7 Fuel Element Manufacturing
(22) Machining - If unenriched uranium metal is to be used as
fuel in a heavy water nuclear reactor, the metal is rolled
or forged by the refining operation into a machinable form.
Core blanks are then machined from the metal and clad to
form fuel elements. The only likely discharges from the
machining process are particulates in the air and in cutting
fluids. High-efficiency dust filters collect the uranium
particles for recycling. All fuels used in the U.S. are
enriched however.
(23) Cladding - Fuel pellets or core blanks are placed in a metal
casing for fission product containment, better heat trans-
fer, and to minimize fuel corrosion before they are put in
reactors. Little pollution from unirradiated cladding is
likely. However, irradiated cladding becomes radioactive
from neutron activation.
9.4.8 Nuclear Power Generation
(24) Reactor - Whether the fuel is oxide or metal, enriched or
unenriched, the power from a nuclear reactor is provided by
nuclear fission. Pressurized water reactors are operated at
high temperatures and pressures for higher energy effi-
ciency. Consequently, if pressure is lost, thermal run-away
can occur as gas bubbles on fuel element surfaces do not
offer adequate heat transfer. Radiation leakage is the most
publicized danger, and even though the system is well designed
from the standpoint of containment, contamination of air or
water is possible. The process can also cause thermal
9-22
-------
pollution. Nuclear power plants discharge four gaseous
o R "-"i 1 "3 1
radio-nuclides, H, Kr, I, and Xe into the atmo-
9 135
sphere. The radio active xenon is also present as Xe.
131
Although I has a short half-life and decays during normal
85 3
handling and storage, Kr and H have longer half lives;
their buildup in the atmosphere or in water could be a
significant hazard when nuclear power production reaches
predicted levels.
9.4.9 Fuel Reprocessing
Solvent Extraction or Ion Exchange - Before they are com-
pletely exhausted, fuel elements are removed from nuclear
reactors and processed to separate fissionable uranium and
plutonium from fission products. First, the fuel elements
are placed underwater at the reactor site for 4 months to
allow short-lived radioactive products to decay. Then the
elements are placed in cooled lead-shielded containers with
crash cages and transported to the processing plant, where
they are again placed underwater. At the processing plant
the fuel elements are removed from the cladding metal,
sheared, and dissolved in nitric acid. Solvent extractions
or ion exchange are used to separate uranium and plutonium
from the fission products. Radiation into the storage water
or into the air poses an obvious potential hazard to the
environment. Further, radioactive fission products create a
considerable solid wastes problem from the standpoint of
perpetual storage. Nearly all the radioactive wastes from
the nuclear industry arise from the reprocessing of reactor
9-23
-------
fuel. Most of this solid waste is stored underground.
Probably the most difficult problem to solve is the release
85
to the atmosphere of Kr from fuel reprocessing plants.
Because of the inert gas character of Kr and Xe, their
p C
removal is a technically difficult task. The Kr is a
long-lived nuclide that tends to build up in the atmosphere.
Several methods are currently under development for the
Q C
removal of Kr from waste gas streams by adsorption,
distillation, extraction, or diffusion. These processes may
p r
remove as much as 90 percent of the Kr that is now being
9
discharged from reprocessing plants.
In general, the mobility of fission products in the
environment is a complex phenomenon which is complicated by
the fact that several members of a beta decay chain can be
translocated because of the mobility of a radioactive
parent. Furthermore small particles of radionuclides are
often transported by virtue of the reactive energy asso-
ciated with nuclear decay, and thus do not require exter-
nally applied force for dissemination.
9.5 MAJOR POLLUTANT SOURCES
All processes of the uranium industry, mining, milling,
refining, fuel element manufacturing and nuclear power
generation, are potential sources of radioactive airborne
dust.
0 Mining and milling processes: Uranium, thorium and
their daughter products are sources of radioactivity, but
9-24
-------
the main source is gaseous radon and its decay products. As
a result of air cleaning and dilution of gases in the
atmosphere, the quantity of airborne dust released to the
atmosphere is usually very small.
0 Refining and element manufacturing processes: Since
the majority of daughter products will have been removed
earlier, airborne products from the purification steps,
consist primarily of dust or fumes of uranium or thorium.
These are usually controlled. Similarly the dust released
from element manufacturing processes consist essentially of
uranium or thorium compounds involved in the process.
0 Reactor: Wastes generated by reactor include four
gaseous radio-nuclides, 3H, 85Kr, 131I and 133Xe. The
radioactive xenon is also present as Xe. Although I
has a short half-life and decays during normal handling and
storage, 85Kr and 3H have longer half lives; their buildup
in the atmosphere or in water could be a significant hazard
when nuclear power production reaches predicted levels
9-25
-------
REFERENCES FOR CHAPTER 9
1. Kirk-Othmer. Encyclopedia of Chemical Technology, New
York. Wiley and Sons, Inc., 1964.
2. DeCarlo, J. A., and Shortt, C. E., Uranium, In: Minerals
Facts and Problems. U.S. Bureau of Mines. 1970.
3. Baroch, C. T., Uranium, In: Minerals Year Book. Vol I-
II. Bureau of Mines, 1967.
4. Woodmansee, W. C., Uranium, In: Minerals Year Book.
U.S. Bureau of Mines. 1971.
5. Crawford and Paone. Facts Conerning Uranium Exploration
and Production. 1956.
6. Clegg and Foley. Uranium Ore Processing. 1958.
7. "Cornell Workshop on Energy and the Environment,"
sponsored by the National Science Foundation, Committee
on Interiors and Insular Affairs, U.S. Senate, 1972.
8. Harrington and Ruehl. Uranium Production Technology.
1959
9. Rivera-Corderu, A., The Nuclear Industry and Air
Pollution. Env. Sci. and Tech., 4(5)392, 1970.
9-26
-------
0 CONVERSION FACTORS °
ENGLISH UNITS TO METRIC UNITS
Multiply
by
Atmosphere 760.0
BTU (British Thermal Unit) 252.0
Cubic foot 28.32
Foot 30.48
Gallon (US) 3.785
Grain 0.065
Horsepower 0.7457
Ounce (avoirdupois) 28.35
Ounce (fluid) 29.57
Pound 453.6
Ton (long) 1016
Ton (short) 907.0
Watt 0.0143
To Obtain
millimeter of mercury
gram calorie
liter
centimeter
liter
gram
kilowatt
gram
milliliter
gram
kilogram
kilogram
kilo calorie/minute
9-27
-------
10.0 RECOMMENDATIONS
It was the purpose of this study to assemble data on
processes and emissions into a standard format developed by
EPA with the goal of identifying processes, which because of
their potential for hazardous pollutant emissions, should be
the subject of further evaluation. Various literature
sources and limited contacts with primarily governmental
agencies served as the primary data bases. The majority of
the useful information which can be obtained by such an
approach is presented in this report. Such an approach,
however, has inherent limitations; for example, useful data
available from such sources as industrial representatives
can be overlooked. In this screening study we have iden-
tified the following processes which should be the subject
of further evaluation. These processes were selected after
qualitatively considering available information on total
quantity of material processed, total mass emissions,
comparative emission toxicity, particle size distribution,
process operating conditions, process growth trends, loca-
tion relative to population centers and degree of emissions
control.
10-1
-------
0 Sintering (iron and steel)
0 Lead sintering
0 Zinc roasters
0 Copper converters
0 Ferroalloy electric furnaces
0 Blast furnace (lead)
° Copper ore crushing
0 Material handling (iron and steel)
0 Reduction cells (aluminum industry)
0 Reduction process (titanium industry)
0 Nuclear reactor
The rationale for selecting these sources is briefly
described below.
Sinter plants (Iron and Steel) - Uncontrolled emissions
from the sintering process average approximately 40 pounds
of particulate per ton of sinter. Seventy-five percent of
the particulate is present in the size range of 1 to 10 u.
Sulfur dioxides as well as volatilized metals are emitted.
The overall degree of emissions control is estimated to be
only 90%.
Considerable quantities of sinter are produced (ap-
proximately 51 million tons in 1967). The overwhelming
majority of sinter is produced on-site at steel plants, of
which approximately 85% are located within Standard Met-
ropolitan Statistical Areas, (SMSA's).
Sintering (Lead Industry) - The lead sinter process
emits (uncontrolled) about 500 pounds of particulates per
10-2
-------
ton of lead. Elements present in the particulates include
Pb, Sb, Cd, Ge, Se, Te, Tn, Tl, Cl, F, and As. The off-
gases also contain substantial quantities of sulfur dioxide
and organic vapors. The overall level of control is esti-
mated to be only 85%.
There are about six facilities with operating lead
sintering machines (1969 data), all of which are west of the
Mississippi. Of the 21 primary lead and zinc smelters,
eight are within SMSA's.
Zinc Roasters - Emissions from zinc roasters contain
As, Ag, Be, Cd, Cr, Hg, Mg, Mn, Ni, Pb, Sb, Se, Sr, and V as
well as significant quantities of SO^. The overall level of
particulate control is reported to be relatively high, but
is unverified.
Zinc production is fairly well split between eastern
and western United States; the majority of the plants in the
eastern U.S., however, are near populated areas.
Copper Converters - About 240 pounds of particulate and
3500 pounds of SO,, are emitted (uncontrolled) per ton of
^
copper produced. The degree of particulate control is
approximately 85 to 90%. Fumes from the converter contain
lead, antimony, arsenic, bismuth, selenium, tellurium, zinc,
cadmium and thallium.
Of the 19 primary copper smelters, eight are in Arizona,
Four smelters are within SMSA's. Except for several in
Michigan, New Jersey, and Tennessee, smelting sites are in
the western portion of the country from Texas to Washington.
10-3
-------
Electric Furnace (Ferroalloy Industry) - Emissions from
ferroalloy furnace vary widely in type and quantity depend-
ing primarily upon the particular ferroalloy being produced;
uncontrolled emissions range from about 40 to 600 Ibs/ton of
product. The emissions contain significant amounts of
potentially hazardous materials. In 1970, overall degree
of emissions control was estimated at approximately 50%.
In 1966, there were 51 listed plants producing ferro-
alloys in 17 states. Ohio led in total production followed
by Pennsylvania; these two states account for 35 percent of
the plants and about one-half of these are located in
SMSA's. Over 2.5 million tons of ferroalloys were produced
in electric furnaces.
Blast Furnace (Lead Industry) - About 250 pounds of
particulate (uncontrolled) per ton of material charged is
emitted. Trace metals present in the particulates emitted
and the range of composition are: Cd, 0.01 to 0.1 ppm; Cu,
0.01 to 0.1 ppm, Mg, 1 to 10 ppm; Mn, 0.01 to 1.0 ppm, Ni,
0.01 to 1.0 ppm; Pb, 0.1 to 100 ppm, Sn, 0.01 to 1.0 ppm and
V, 0.01 to 0.1 ppm. Recovered fumes, which are sent to
cadmium treatment plants, contain Pb, Sb, Se, Te, Cl, F, In,
Tl, Zn, Cd and As. Slag formed in the furnace contain the
oxides of Fe, Ca, Si, Al, Mg, and Mn. Essentially all blast
furnaces in the industry have some kind of control; overall
control efficiency is estimated to be only 85 percent,
however.
There are approximately six primary lead smelters, all
located west of the Mississippi,
-------
Copper Ore Crushing - Approximately 200,000 tons of
particulate is emitted per year from crushing operations;
this represents nearly 70 percent of the total particulate
emissions from the copper industry. Composition of the
particulate is the same as that of ore. Free silica in the
ore may be appreciable and pose a health hazard. Most of
these operations, however, are confined to remote areas.
Material Handling (Iron and Steel Industry) - In 1970,
approximately 445,000 tons of particulate was emitted annually
from the material handling process in the iron and steel in-
dustry. Composition of the emission is essentially the same
as the ore. The fugitive dust emissions created by mate-
rials handling are a problem in both rural and urban areas.
Reduction Cells (Aluminum Industry) - Hydrogen fluoride
is the emission of primary concern. All plants have primary
control equipment, but in many cases their operating ef-
ficiency is not high enough to be satisfactory. Furthermore,
few plants have secondary emissions control (i.e., control
of pot-line emissions that escape the hoods). Of the three
kinds of cells in the industry, the horizontal-stud Soderberg
cells have the highest emission rates. The emissions also
contain alumina, tar-pitch distillation products, oxides of
sulfur and carbonyl sulfur.
In 1968, there were 24 primary aluminum reduction
plants in the United States with a total capacity of approxi-
mately 3.5 million tons. One-third of these plants were
within SMSA1s.
10-5
-------
Reduction Process (Titanium Industry) - Atmospheric
emissions contain TiCl2 and MgCl2 vapors. The most sig-
nificant problem however, is the relatively large amounts of
solid waste containing metallic chlorides which must either
be landfilled or dumped at sea.
Nuclear Reactors - Wastes generated by reactors contain
four gaseous radionuclides, I, H, Kr and Xe. Many
hundreds of additional radioactive fission products may
exist as suspended solids. Of particular interest biolog-
137 134
ically and from a solubility standpoint are Cs, Cs,
and Sr because of their ready intake by the body and
concentration in the food chain. The rare earth fission
products also are biologically mobile enough to be of
serious threat.
Wastes from the nuclear reactor present a potentially
severe environmental problem. With the expected growth in
nuclear power generation, these sources could be of over-
whelming importance.
The next study phase should consist of obtaining de-
tailed information for each of these processes on the
emission characteristics and the approximate degree of
emissions control. This phase would entail several plant
inspections of each process, and discussions with appro-
priate personnel from the industry, their design/process
engineers and emission control equipment manufacturers.
Emission source tests may also be required for several
processes to obtain necessary data on emission particle size
distribution and composition.
10-6
-------
A consistent quantitative procedure of ranking these
processes should then be used to identify the most sig-
nificant sources. This procedure should encompass the
qualitative factors, listed above, which were used in the
initial selection. For example, such a procedure might
include determination of the "area of significant pollution
impact;" such an area could be estimated by considering
probable distance of significant pollutant transport coupled
with probable health impact. Health impact determinations
should be based upon consideration of the particle size
distribution and particle composition. Such a study should
be a cooperative effort with EPA's Health Effects Research
Laboratory. Once the "significant impact area" is deter-
mined, the population living or working within such areas
could be determined and an emissions control priority
established for all processes, not only for the significant
sources identified by this study but for those identified in
parallel studies.
10-7
-------
APPENDIX A
METAL PRODUCTION AND CONSUMPTION STATISTICS
(1971)
A-l
-------
PRIMARY (METAL CONTENT)
MINE (ORE) 1,0/5
SMELTER (BY-PRODUCT) 11,374
IMPORTS I3,j/y
EXPORTS
(ORE, METAL, ALLOYS) 1,023
SECONDARY zO,y|/
All values in short tons v
otherwise indicated.
^
inless
PRODUCTION
PRIMARY
METAL 3,816
OXIDE 6,272
ci II cmc 1 Q
JULrlUt lo
RESIDUES 136
ANTIMONIAL LEAD 1,132
TOTAL 11,374
SECONDARY
ANTIMONIAL LEAD 15,839
flTUJCD ICAfl Al 1 ("NVC
-------
IMINF PRODUCTION ?r22&/Ann| **
| IMPORTS 13,805, 100 | "^
Irvn/^rvrc 10 1 rwt L_« _._.__
tXrUKia Jo, IUU J^ ~
^PROCESSED 16,031,7001 1
CONSUMPTION
USERS
ALUMINUM
ABRASIVE
CHEMICAL
REFRACTORY
OTHER
PERCENT
93.6
1.3
2.0
2.4
0.5
All values in short tons unless
otherwise indicated.
Figure A-2 Bauxite (aluminum ore) production and consumption statistics (1971).
-------
PRODUCTION
IMPORTS
[EXPORTS
W
424
36
REFINERY}-
USERS
FUSIBLE ALLOYS 257
METALLURGICAL ADDITIVES 181
OTHER ALLOYS 9
PHARMACEUTICALS 362
EXPERIMENTAL 13
OTHER 2
TOTAL 824
All values in short tons unless
otherwise indicated.
Figure A-3 Bismuth production and consumption statistics (1971).
-------
>
PRIMARY AND SECONDARY
(METAL CONTENT)
IMPORTS 1,750
EXPORTS 33
""CJREFINING
PRODUCTS
CADMIUM METALS
AND COMPOUNDS
5,416
All values in short tons unless
otherwise indicated.
Figure A-4 Cadmium production and consumption statistics (1971)
-------
[IMPORTS 1,299,0001
| EXPORTS 180,000 T I
[CONSUMPTION i,o93,oooTE::T*'
STOCK
26,000 I
All values in short tons unless
otherwise indicated.
CHEMICAL
180,000 T
(45.6% ar2O3)
REFRACTORY
193,000 T
(36.3% Cr2O3)
METALLURGICAL
720,000 T
(47.8%Cr2O3)
USERS
STEEL:
CARBON
S.S. AND HEAT RESISTANT
ALLOY
TOOL
CAST IRON
SUPER ALLOYS
ALLOYS:
CUTTING AND WEAR RESISTANT
WELDING AND HARD FACE
NONFERROUS
OTHER
MISCELLANEOUS AND UNSPECIFIED
OTHER
TOTAL
Figure A-5 Chromite production and consumption statistics (1971).
-------
IMPORTS* 5,456
(COBALT CONTENT)
REFINERY
PRODUCTION
METAL
ALLOY AND CONCENTRATE
HYDRATE '
OTHER
2,450
1 78
All values in short tons unless
otherwise indicated.
* SOME COBALT ALSO RECOVERED
AS A BY-PRODUCT FROM PROCESSING
OTHER ORES.
W = DATA WITHHELD INCLUDED IN TOTAL
USERS
STEEL:
CARBON 1
S .S. AND HEAT RESISTANT 25
ALLOY (EXC . S.S. AND TOOL) 98
TOOL 159
CAST IRON W
SUPER ALLOYS 992
ALLOYS:
CUTTING AND WEAR RESISTANT 615
WELDING AND HARD FACE 123
MAGNETIC 1,139
NONFERROUS 266
OTHER 235
MILL PROP. W
CHEMICAL AND CERAMIC:
PIGMENTS 73
CATALYSTS 237
GROUND COAT FRIT 69
GLASS DECOLOR IZER 30
OTHER 51
MISCELLANEOUS AND UNSPECIFIED 766
SALTS AND DRIERS 1,372
TOTAL 6,250
Figure A-6 Cobalt production and consumption statistics (1971).
-------
COLUMBIUM (METAL CONTENT)
MINE PRODUCTION W
RELEASE FROM GOVERNMENT STOCK 309
IMPORTS:
MINERAL CONCENTRATE 2,860
Cb METAL AND ALLOYS 1
FERRO COLUMBIUM NA
CONSUMPTION 1,645
EXPORTS
ORE AND CONCENTRATE
METAL, ALLOYS, COMPOUNDS
(GROSS)
NA
23
CONSUMPTION
COLUMBIUM METAL 130
FERROCOLUMBIUM
AND FERROT ANT ALUM -
COLUMBIUM 1,296
CO
TANTALUM (METAL CONTENT)
MINE PRODUCTION W
RELEASE FROM GOVERNMENT STOCK 50
IMPORTS:
MINERAL CONCENTRATE 523
TA METAL AND ALLOYS 25
CONSUMPTION 867
EXPORTS
ORE AND CONCENTRATES
METAL, ALLOYS, COMPOUNDS
(GROSS)
METAL AND METAL POWDER
61
325
70
CONSUMPTION
TANTALUM METAL
FERROCOLUMBIUM
AND FERROTANTALUM-
COLUMBIUM
209
1,296
W = WITHHELD FROM USBM STATISTICS
All values in short tons
unless otherwise indicated.
-------
vo
ORE PRODUCED
(OPEN PIT 88%
UNDERGROUND 12%)
242,656,0001
(0 .55% Co M
1,522,183
(COPPER CONTENT)
IMPORTS
ORE, MATTE, ETC.
181,259
(COPPER CONTENT)
SMELTER
1,470,815
(COPPER CONTENT)
-*•
REFINERIES
FROM DOMESTIC ORES 1,410,523
FROM IMPORTS 181,259
PRIMARY COPPER
1,591,259
USERS
BRASS MILLS
WIRE MILLS
FOUNDRIES
CHEMICAL PLANTS
AND MISC.
SECONDARY
SMELTIRS
* ALL VALUES IN SHORT TONS UNLESS OTHERWISE INDICATED.
Figure A-8 Copper production and consumption statistics (1971).
-------
I
o
DOMESTIC PRODUCTION ( 5% MN)
(OPEN PIT 93 .8%
UNDERGROUND 6.2%)
HEMATITE 64,075,200
LIMONITE 6,516,200
MAGNATITE 167,362,700
TOTAL 237,954,100
BY-PRODUCT ORE 935,200
IMPORTED ORE 50, 261 , 100
EXPORTED ORE 6,151,000
— H TO BENEFICATION 230, 13 7,600 \—*~
AGGLOMERATES 64, 780,800 »
CONCENTRATES 27,933,900 >
BLAST FURNACE
* ORE 31,726,000
AGGLOMERATES 112,421,000
STEEL FURNACE
ORE 2,391,000
AGGLOMERATES 941,000
•] FERRO-ALLOYS
•JIRON OXIDE PIGMENTS 75,849
HCEMENT |
ALL VALUES IN SHORT TONS UNLESS OTHERWISE INDICATED.
Figure A-9 Iron production and consumption statistics (1970).
-------
M
M
DOMESTIC ORES
(LEAD CONTENT)
LEAD ORE 458,691
ZINC ORE 8,291
LEAD-ZINC ORE 93,991
COPPER 12,929
OTHER 4,648
TOTAL 578,550
IMPORTS
ORE AND MATTE 65,998
BASE BULLION 41
PIGS AND BARS
[EXPORTS 5,925
HOT
•*
REFINERY
PRIMARY LEAD
FROM DOMESTIC ORES 573,022
FROM IMPORTS 76,993
ANTIMONIAL LEAD
LEAD CONTENT 16,116
ANTIMONY CONTENT 1,191
— »-
USERS
METAL PRODUCTS 366,563
BATTERIES 679,803
PIGMENTS 81,258
CHEMICALS 264,641
MISCELLANEOUS 23,498
UNCLASSIFIED 15,751
TOTAL 1,431,514
ALL VALUES IN SHORT TONS UNLESS OTHERWISE INDICATED.
Figure A-10 Lead production and consumption statistics (1971).
-------
NJ
MAGNESIUM CHLORIDE
SEAWATER
BRINE
ELECTROLYTIC
REDUCTION
PRIMARY METAL
123,485
[MAGNESIUM SCRAP
[IMPORTS 3,67i "]•
REFINERY
SECONDARY METAL 13,148
[EXPORTS 24,311
USERS
STRUCTURAL
CASTINGS
WROUGHT PRODUCTS
SUBTOTAL
DISTRIBUTIVE OR SACRIFICIAL
POWDER
ALUMINUM ALLOY
ZINC ALLOY
CHEMICAL
ANODES
REDUCING AGENT
(Ti, Zr, Hf, U, Be)
NODULAR IRON
OTHER
SUBTOTAL
TOTAL
11,945
13,290
25,J35
3,410
39,988
39
9,088
9,416
5,588
4,135
2,282
73,866
99,101
ALL VALUES IN SHORT TONS UNLESS OTHERWISE INDICATED.
Figure A-ll Magnesium production and consumption statistics (1971).
-------
U)
MANGANESE ORE
DOMESTIC PRODUCTIONS
OVER35%MN 142
5-35% MN 198,334
IMPORTED ORE
OVER 35% MN 1,914,264
TOTAL 2,112,740
— »-j BLAST FURNACE | — »-
— H ELECTRIC FURNACE | — »-
— *-| ELECTROLYTIC CELLJ-^*-
FERRO-
MANGANESE
MANGANESE
ALLOYS
MANGANESE
METAL
MANGANESE
CHEMICALS
FERROMANGANESE
PRODUCTION 759,896
IMPORTS 242, 778
EXPORTS 4,526
USERS
MANGANESE ALLOYS
AND METAL 1,837,683
PIG IRON AND STEEL 187,251
DRY CELLS, CHEMICALS
AND MISCELLANEOUS 130,520
TOTAL 2,155,454
* ALL VALUES IN SHORT TONS UNLESS OTHERWISE INDICATED.
Figure A-12 Manganese production and consumption (1971).
-------
PRODUCTION
a
RECOVERED
IMPORTS
670
2,212
EXPORTS
217
SECONDARY
633
All values in short tons
unless otherwise indicated.
H
USERS
AGRICULTURE
AMALGAMATION
CATALYSTS
DENTAL PREPARATION
ELECTRICAL APPARATUS
ELECTROLYTIC CHLORINE AND CAUSTIC
GENERAL LABORATORY USE
INDUSTRIAL AND CONTROL INSTS.
PAINT:
ANTIFOULING
MILDEW PROOFING
PAPER AND PULP MANUFACTURE
PHARMACEUTICALS
OTHER
TOTAL
56
W
43
91
644
466
69
185
RECOVERED FROM ORE MINED PRINCIPALLY FOR MERCURY CONTENT
W = WITHHELD
Figure A-13 Mercury production and consumption statistics (1971)
-------
CONCENTRATE (METAL CONTENT)
PRODUCTION
IMPORTS
54,796
427
PRIMARY PRODUCTS
MOLYBDIC OXIDE 24,959
METAL POWDER 1,209
AMMONIUM MOLYBDATE 850
SODIUM MOLYBDATE 430
OTHER 6,057
TOTAL 33,508
All values in short tons unless
otherwise indicated.
Ul
USERS
STEEL:
CARBON
STAINLESS AND HEAT RESISTANT
ALLOY
TOOL
CAST IRONS
SUPER ALLOYS
ALLOYS:
WELDING AND HARD FACE
OTHER
MILL PRODUCTS FROM POWDER
CHEMICAL AND CERAMIC
PIGMENTS
CATALYSTS
OTHER
MISCELLANEOUS
TOTAL
1,095
2,472
8,609
1,121
1,742
864
188
137
J,061
Figure A-14 Molybdenum production and consumption statistics (1971).
-------
ORES
(NICKEL CONTENT)
DOMESTIC
BY-PRODUCT
TOTAL 15,65*
| IMPORTS
[EXPORTS
13,073
2,581
142,183
{SECONDARY 29,6571—'
REFINERY
26,143 h*
PRODUCTS
METAL
FERRO-NICKEL
OXIDE
SALTS
OTHER
TOTAL
95,639
11,332
16,751
2,376
2,718
128,816
USERS
STEEL:
STAINLESS AND HEAT RESISTANT
ALLOY (EXC. STAINLESS)
SUPER ALLOYS
ALLOYS WITH COPPER
PERMANENT MAGNET
OTHER {NICKEL AND ALLOYS)
CAST IRON
ELECTROPLATING
CHEMICALS
OTHER (BATTERIES, CHEM., ETC.)
TOTAL
128,816
* ALL VALUES IN SHORT TONS UNLESS OTHERWISE INDICATED.
Figure A-15 Nickel production and consumption statistics (1971).
-------
PRIMARY METAL
DOMESTIC ORE
IMPORTS
ORE (TIN CONTENT)
METAL
EXPORTS
H
-J
3,427
52,573
REFINERY}-
| SECONDARY METAL 22,508 |-
2,533
USERS
ALLOYS (MISCELLANEOUS)
BABBITT
BAR TIN
CHEMICALS
COLLAPSIBLE TUBES AND FOIL
PIPE AND TUBING
SOLDER
TERNE METAL
TINNING
TIN PLATE
TIN POWDER
TYPE METAL
WHITE METAL
OTHER
TOTAL
78,344
ALL VALUES IN SHORT TONS UNLESS OTHERWISE INDICATED
Figure A-16 Tin production and consumption statistics (1971).
-------
M
00
RAW MATERIALS
ILMENITE CONCENTRATE
MINE SHIPMENTS 713,549
RUTILE CONCENTRATE
IMPORTS 215,109
TITANIUM SLAG 147,191
IMPORTS
ILMENITE CONCENTRATE 185,618
RUTILE CONCENTRATE 215,109
TITANIUM SPONGE 3,023
TiO
USERS
PIGMENTS 769,486
WELDING ROD COATING
AND FLUXES 14,857
ALLOYS AND CARBIDE 1,104
CERAMICS 390
GLASS FIBERS, METAL
AND MISCELLANEOUS 21,322
TOTAL 807,159
TITANIUM METALS
USERS
JET ENGINES
AIR FRAMES
SPACE AND MISSILES
INDUSTRIAL
* ESTIMATED
PERCENT*
51.0
26.0
7.0
16.0
100.0
All values in short tons
unless otherwise indicated.
Figure A-17 Titanium production and consumption statistics (1971).
-------
I**~f"lMf~C(-slTD ATT DD(^r»t ll^TIOKI 1A GdCl 1 ...„_.,.. IM»
(_CTN(_LIN IKAI L r KUUUL 1 IUTN J4,OUU j" •— •• i»
\J{J VLKIN/viLiN 1 DUJV^Iv. OY 1 l~ "~ — ^~
IrvDOOT^ i nni 1*
LArUKiJ I,UUJ p^— — — -
All values in short tons unless
otherwise indicated.
PRODUCT.)
TUNGSTEN:
POWDER 1,559
CARBIDE 2,575
CHEMICALS 1,326
OTHER 406
TOTAL 5,866
USERS
STEEL:
STAINLESS AND HEAT RESISTANT 94
ALLOY 74
TOOL 710
CAST IRONS 8
SUPER ALLOYS 105
ALLOYS:
CUTTING AND WEAR RESISTANT 2,541
OTHER 402
METAL MILL PRODUCTS 1,022
CHEMICAL AND CERAMIC 191
MISCELLANEOUS 435
TOTAL 5,580
Figure A-18 Tungsten production and consumption statistics (1971).
-------
NJ
O
MINE
ORE (GROSS WT . 6,279,000)
MILL
CONCENTRATE
(U308)
IMPORTS
CONCENTRATE
(U3o8)
122,731
942
REFINERY
UF6
U°2
All values in short tons
unless otherwise indicated.
Figure 19 Uranium production and consumption statistics (1971).
-------
K)
H
PRODUCTION (METAL CONTENT)
ORE AND CONCENTRATE 5,252
IMPORTS
FEERO VANADIUM 89
EXPORTS
FERROVANADIUM AND OTHER
ALLOYING MATERIAL 675
ORES, CONCENTRATES, OXIDES
AND VANADATES 260
All values in short tonB
PRODUCTS
FERROVANADIUM 4,171
VANADIUM OXIDE 143
AMMONIUM
METAVANDATE 35
OTHER 453
TOTAL 4780?
USERS
STEEL:
CARBON 830
STAINLESS AND HEAT RESISTANT 30
ALLOY (FXC . STAINLESS AND TOOL) 2,530
TOOL 441
CAST IRONS 56
SUPER ALLOYS 14
ALLOYS (EXC . STEEL AND SUPER ALLOYS)
CUTTING AND WEAR RESISTANT 8
WELDING AND HARD FACE 10
NONFERROUS 363
OTHER 7
CHEMICAL AND CERAMIC 1 14
MISC . AND UNSPECIFIED 399
TOTAL 47561
unless otherwise indicated.
Figure A-20 Vanadium production and consumption statistics (1971).
-------
I
N)
KJ
DOMESTIC ORES
(ZINC CONTENT)
ZINC ORE
LEAD ORE
ZINC-LEAD ORE
COPPER ORES
OTHER
TOTAL
EXPORTS
267,789
51,351
155,368
42,521
17,107
534,136
IMPORTS
ORES (ZN CONTENT) 525,759
SLAB ZINC 270,413
288
REFINERY
SLAB ZINC
FROM DOMESTIC ORES 403,953
FROM IMPORTS 473,858
USERS
GALVANIZING
BRASS PRODUCTS
ZINC BASE ALLOYS
ROLLED ZINC
ZINC OXIDE
WET BATTERIES
DESILVERIZING LEAD
LIGHT METAL ALLOYS
OTHER
TOTAL
17196,951
* ALL VALUES IN SHORT TONS UNLESS OTHERWISE INDICATED.
Figure A-21 Zinc production and consumption statistics (1971).
-------
APPENDIX B
IRON ORE MINING AND PRODUCTION STATISTICS
B-l
-------
Table B- 1 Economic Facts of Life Place On-Going Emphasis on Pellets as U.S. Natural Ore Operations Continue Phase~O
Ore/ Or* Conean- Concan-
Mlnlng Drilling Htulag* Wmla Mined Ort O>* trull lr»l>
1973.
. , , Pcltel Sinl«r Produc- Grade Shipping EiDan-
Aggtom- Equipment Capacity Capacity lion Final .Dtllina- •"-•--•• p
to
I
jr-atlon/Ucillon *
£jg!o MOL/nlaff) mine
fcng't MounH-n. C*l»- 100%
Cmnir* mint*
P|lm»r, Mtcn. 40%
25%
20%
13%
Republic mint*
Rflput-UC. MtC*l.
Malher-0 .I.P.-Pionew1
Negau'ie* Mich.
Humboldt Mining Co.'
Mjmboldt. Mich. &0%
50%
Tltdcn Mine-Project
30%
10%
B%
5%
Groveland mine
BruMH, MTJ» 100%
Sherwood mine
0 . C
Mesaba Cliffs
Colinm*. Minn. 33%
IS 4%
16%
139%
' Mining Co.
,ioyt LiKet M.nn. 45%
3!>%
10*
10%
Evelolh T>conlle Co.
15%
Butler Taconile
COQlBy, Minn.
National Sieel Pellet
Plant FVXi
KfBwatm, Minn U%
Pierce minp
H>hb'"T. Minn
HiM Annr?x mine
CHur"«t. Mrctv 100%
Lind Greenway mine
G'ind Hap.di Mmn. 100%
McKmley mine
UttOMiy. Minn. 100*
Reserve Mining Co,
6 ,t,f I', W">n 50%
S.'^r Qiy. M'on." 50%
Arciu'us mine'1
'.'»'tj'« Minn 100%
Plurnmor mine
Co'Bralft*. Mmn. tOO%
Minntac
Mounltln rron. rjlrtn. fOO%
ichteau mine,
«hgirM», Minn 100%
Ghnrman mine
hi%t'clm.Mlf.r».
Sicphona mine
Aurori, M,r*i. 100%
Ownership Startup
*""' "**' It4i
In(*nd Sl"*( tWJ
CtfVfltntf-CriflV
ltC4. Hitviilflr
CUMlind Cllltt 1»M
Jerwi | LaugMin
till t H»iyr»i*i
Whtil'rtg Prtt«bwe>
— 1965'
CHwliftd-CUrti 1WW»
Ford Motor
AlfomA $)t«.| 1074
Jon*<<& Ldua^'n
CUveUnd-CMIIf
S'flko
Whtjolmg.PltlibufQh
Sh»fon 5>F«> '
Ktnm Mining 1flM
Jon?* f| i.ijqnlln n.i.
Dcl'OH Slf B'
Cltrilind-CWIt
Wh«e»nq i'i!UbufBh
Nnnonal Stool
Oc^tfl^crri Sff«' 1957
Vounjsiown S t T
Sic't»
Inlirl^Kv
Mckifidi Mllhtt
FordMoior 1845
Oglebty Noilen
lUmi Mmm 186'
Wb*9l- nl Sloo' "»W
Jonet t Uug*iiin 1B17
Jortoi & LiugMin 1860
JODBt & L»u0hllfl 1BU
Armca Sie«l 1955
Pfputii'cSt**!
U S, S'*«t n •
U.S. Si.*l fit.
U.SW* 1967
U.S. Slsil 1943
.
U.V SIM) * •&;
Method
Op*np!l
op»tpJl
.,-,,.
undBT'
r»*«««i
opwpfl
optn pn
op.n pit
roiwi
op*f> pit
open pit
op«n pit
optn pit
•n II
optn pit
ep>n pff
op*n pit
»p«n pit
op«n pit
cp*n pH
optn pit
op*n pit
ownp
e
JM30
n.m
8130
~
».t40
I4.I90
29.400
13,159
24,000
23.400
Z4.000
JI.JOO"
1»,JO«ri
M.TOO"
•9.000
ft.t
n ft.
n.«.
Mlnoroli arid* (Ipd) Gr«d* •t«llon u»d (tpd)
Mmalitt ,,ll(
mlgnffllta 31% 10.720 R.a. p«H«l« prala kiln t.940
"•""""• »»• '«• -
htmititt eo.1% n.i. n.« 7 c,.i. hMn (6SO
— — — *" p*ll»l» grile kiln t.BW
Somillt. 3ft% 13.300 - p.tl.1, QrlM kill, 1U80
m.gi-M*. 35,5% S.T30 64.0% p*llt|» 1rt,«ling 5,550
t 1 ••
ritmalltt
himiilie 3ft% 1,100 — — — —
migntllU :?% 2D.B13 M 35% pt"«tt «h»" 38.;?i
lum»cti
mign«Hl* 23% ft. 000 6T.J% p*H(l» , Quit kltfi 6.400
mig^tlltt 31.21% 7.641' 690% ptlltti gnu utn 7,64f
magnflite,
hfmafiin. 3J.39% 7.5U JO 47% — — —
lliiOlilH,
gool'titf)
hCT»«'"«, 3570% 5,3«?6 59,54% — — —
QMlhltt
hcrmtll*, 97.7% ig.OOO «1 74% — — _
gnlhlt*
mignvtitt 24% 2S.OOO 64% p«l.»t| travgl.ng 30000
gnu
hamilll* nt. n •. n i. • — M —
mign«lll* 100.000 p*Mtl| g,t\t t,\\n 24,250
rn»rn«,t!i» n.m n • n.i. — _ _
llmonlli
Urnonll*
n.iL n.i. n ». — — —
^vvacrif i,on
— f.ooo.eco'
— 3.S70.000
— 2,650.000
121.000
COartt On]
— 990,000
— —
— 2.000.000
~* 310,000
~ 1.000,000
— 9,971,080
— 2,141.233
- 2,269,854
1,100000'*
— 649,000
~" «f2.(WO
"~ 1,985,000
— 9.042.632
— l.t&t (40
WWI
— 3.158.67J
— 2.658,010
0M.C21
Fmal Deslina-
Product lion
M» fOT».. C..
64% Ifivref IIHV
64.6% lowttr 1«h«
56 2% '
»,«% ratv«r !**•
85.3% Ciitda.
lower Ilk*
83 2% n t
E«i
CH'C*go,
ind.
66% low«f Uk«
64 4% l»-
'*'. bo« non,
'*'!. fcwf none
'Hi. bo«t —
rill, bo«| no^
'•'I. bOajt ^^
can. boil .,0rtfj
rail, botl non*
r*il, Doit ¥Sin
rail, bott „,,„.,
mil, bat) noot
rill, boat . nona
fifll, bOtl
rii'. boat nont
rail, bosl nan«
non»
rail, boit yfl,if
«M. d«i non.
rail rnAI .—
-------
Table B-l (continued) .
Economic Facts of Life Place On -Going Emphasis on Pellets as U.S. Natural Ore Operations Continue Phase-Q
Oponllon/Locollon %
'ol Knob Pellol Co.
Mol Knob, Mo. SO1*
SO*
Mflranoc Mining Co.
Sullivin, MO. 50'*
10%
New York Ore dlvltion
w
1 G'ace mine
Morgar>lown. f*. 100%
OJ
Lone Star Slee) Co.
Lo*o Star, !••*» 100%
Comstock mine
CrdarCiiy. Ulth 100%
Dcsorl Mound mine
CedsrCHy. Ul*rt 100%
Iron Springs mine
Odor City, Ulih
B'^nk Fliver Fa'ls mine
Sunrise mine
r nrl.e vvvo 100%
• . - ..'•., Ore
Opfrjiponi 100%
L*nt?«f, Wyo
Mining
Ownerih!p Startup Method
Granite Cfly 1«9 undar-
Htnn» Ulnlnfl 0roUhd
B»lMflh«m SUfl t9M undir-
St. Joi WinttUt ground
1(
Bi(h)th«m &t«*1 IKfl und«f-
O'ound
Lot* S!»f Sl«*l 1947 op*n pit
CFAI 5I**< tP53 op«np4t
U 9. &t»l 1PJ1 op*npll
Ulitt Inl'l. 1943 oponph
U.S Sle«l 1962 octn pit
Ore/
Prilling Hautaga Weitf
Method Mothod (Ipd)
ptrcus- truck. 7.JOO
Itofl convey of,
Or
parcui- '»"• 10.72S
lion conveyor.
loid-hiul-
dump
rctfy, (nick 17,309
lion
percu*- comvyOf (.000
»lon
non»'» injck, 9.0*0
rot* FT (ruck i? BOO
roUry liucK 4,000
rotiry truck v«r1i^<«
ro'try r,H 32.000
Ore Conctn- Conctrv
Mlned Ore Or« tralo tralg
((pd) Minarali Qrad* (Ipd) Qrad«
3,000 mig^t'lt 35.3% 3.000 eS.2%
-
10. WO magnBt'ta. 49.1% fl.500 67.6%
•pitilc (meg Ft)
1C 300 ff>4K((t«, J3%, 10 000 67%
6.300 magnallii. ^0.^% 4iGOO $5.5-66.8%
py'll*.
chgliopyrllt
13,920 'iTo-.le, 27 B-<% 3.707 42.B3H
4.?M wppnelirt. 531% na p §
M->«lit«.
1.500 - 60%
3.200 =^. 30.50% 4,000 61%
13400 n.l. !6Tt (.000 642%
1972
Pellet Slnler Pioduc- Gtade Ehlppinj Enpan-
r II, C»n.icJI» lion final Doslim- Shippmj >ion
A°g'km' |i?n (ipdl (lpd> (toni) Product lion Melhod Plunt
M )% O'inlieCllj riil foni
e«lieU trivellftg 5,000 ~~
B'llt
1Bfi3S24 610% vanougclIlM Ilil, dUCh nbnt
Ptllttl >rii" 6,900 '• sa' |n ^ g
tvmicM
_ — 3.000 »M,6St 86% J * L mllli "" ron*
••1313T 655.6SS% BellHehtm nil "»"•
pl'IHtl »h«" 6-WO — ,,.32,12.' 03.3 QT1.3T* ^
fuintcts
_ J.(|T SI9.330 50S«% lti« 5W '•'' "Ont
•""" sle«l will
., ,u Piinblo, raM n_no
_ 919.235 531% nOn«
_ _ S30.DOO - Pfovo, r-J1 n0"*
Utah
600000 M* P'o.o, '•" »«"•
~ — Ulah
P.II.U t1r.lflht oral* 3,300 - 697,000 65% El.l ChjcaflO. '•'» "»"•
_ 5*1.7*5 51% PueW°. '*'" n°"«
Coio
p«tl«K flfflie hlln 5000 ~ '• O0'09 ut>h
11 Dfiglm* »
-------
APPENDIX C
PPODUCTION STATISTICS OF FERROALLOYS
C-l
-------
Table C-l FERROALLOYS PRODUCED AND SHIPPED FROM FURNACES
IN THE UNITES STATES (1971)
Alloy Gross weight
(short tons)
Ferromanganese 759,896
Silicomanganese 164,682
Ferrosilicon 687,166
Other chromiums 107,493
Ferrotitanium 3,363
Ferrophosphorus 101,353
Ferrocolumbium 830
Others include 86,329
Alsifer, ferroboron,
ferronickel, ferro-
molybdenum, ferro-
tungsten, ferro vana-
dium, Simanal, Spie-
gelsen, Zirconium-ferro-
silicon, ferro silicon-ziroco-
nium and other miscellaneous
ferroalloys.
Total 2,331,055
Alloy element
continued
(average percent)
78.6
66.0
68.3
44.0
28.2
24.0
61.4
44.1
62.6
C-2
-------
Table C-2 PRODUCERS OF FERROALLOYS
IN THE UNITED STATES IN 1971
Producer riant location Product ' Type of furnace
Atrriro Chemical ("<>_ _ Pierre, F!a ......__.__. FrP Electric.
(Culvert City, Ky ... |
Airco Alloys & Carbide ......._ i Charleston, S.C . . (KcC'r Fpf'rSi FeMn I
j Mobile, Ala f FeSi, .SiMn' Silvery Do
(Niagara Falls, N.Y ) iron. j
Alabama Metallurgical Corp Selma, Ala KeSi Dn
Bethlehem Steel Co Johnstown, Pa . . _ FeMn"" Blast
Chromium Mining & Smelting Co. . Woodstock, Term .... FeMn, SiMn, FpCr, Electric
FeSi, FeCrSi.
Climax Molybdenum Co I^angploth, Pa . FeMo Aluminothermic
Diamond Shamrock Corp KingMood, VV. Va FeMn Elpf.tric
FMCCorp.... . Pocatelld, Idaho.. _ FeP _.....".'.""." "_ Do.'
f Cambridge, Ohkv ..
Graham, W. Va.
Fell, FeCb. FeTi, FeV,
FeCr, FeCrSi, Fc.Si,
vjranam, v> .
Foole Mineral .Co.. . .. ...... < Keokuk, low
I Vancoram, Ohio. ..... i Silvery iron, other
I Wenatchee, Wash . . _____ |
Hanna Furnace Corp . . _________ . Buffalo, N.Y ______ ____ Silvery iron _____ ______ Blast.
Hanna Nickel Smelting Co _____ , Riddle, Oreg .......... . FeNTi _ Electric.
Hooker Chemical Corp ....... ___ ., (Columbia, Tenn _____ _ FeP . Do
Interlace Steel Corp ..... __________ Beverly, Ohio ... . FeCr, FeCrSi, FeSi Do
SiMn.
Ka»e<-ki Chemical Co ..... ------ F.astan.Pa, .. ......... FpCI) ... ........ Atuminotbermic.
Mobi! C'hemical Co _____ .... . .. Nichols, Fla . . ...... FeP ____ _. Electric.
Molyhilenupi Corj>. n[ America . . Washineton, Pa _________ FeMo, FeW, FeCh, Electric and
Feb. aluminothermic.
Monsanto Chemical Co ____ ____ /Columbia, Tenn )„ „ _,
iSoda Spring, Idaho".".' " I ". I fel - - ------------- E.ectnc.
Nl, Industries, Inc . _____ ....... _ Niagara Falls, N.Y ______ FeCTi, FeTi. other *. .. Dn.
New Jersey Zinc Co. ____________ Palmertcm, i'a _ Spin Do
I Brilliant, Ohio )
Ohio Ferro-Alloys Corp. . _______ . . | Philo, Ohio . .._ . ____ I FeCr, FeSi. FeB, 1 n
ll'nwhatan, Ohio. . ( FeMn, SiMn, other.' / L '
ITacoma, Wash __________ )
Kea fling Alloys ________ ....... .. Robesonia, Pa. ...... . ,_FeCh, FeV Aluminothermic.
Shieldalloy C'orp ....... ..... ____ Newfield. N.J ____ . ____ FeV, FeTi, FeB, FeCb, Do.
NiCb, CrMo, other. i
KtaufTer Chemical Co ...... ______ 'Mt. Pleasant, Tenn 1 ., „ .,,
\Silver 'Bow, Mont. ..:..:!FPP -------------- Llectric.
Tennessee Alloys Corp. ...... ___ Bridgeport, Ala ___ ..... . FeSi,. ..... ........ Do.
Tennessee Valley Authority.. ..... Muscle Shoals, Ala FeP D<;
Term-Ten Alloy Chemical Corp. of Houston, Tex, . . . ...... FeMn, SiMn" ~ .'.'.'_"_'.'' Do!
Houston.
,'Mliiy, W. Va _________ 1
jAshtabula, Ohio.. ______ | F<"H. FeCr, FeCr.Si, |
Union Carbide Corp . . i Marietta, Ohio ( FeCb FeSi FeMn I „
1 Niagara Falls, N.Y _______ | FeTi. FeW. FeV. f L'°-
'Portland, Oreg.. . . | SiMn others
• Sheffield, Ala . . I
l.'.R. Steel Corp. ....... .... ;Clairton,P
'
McKeesport. Pa".
„ ., ...
FeMn -------- ----- Hlast'
. . . . . . . _
Woodward Iron Co . . . i Woodward, Ala 1 .,
•""i
' CrMo, Chromium rnnlylidpiium; FeMn, fprnimaujjanese; Spin, spipgelr-isen; SiMn, silicr.maneanese; FeKi,
ferrnsilicon; FeP, fcrroiihosphorus; FeCr, fernichromium; FeMo, ferromolyb'lenum; FeN'i, ferronickel; FeTi,
ferrotitimium; FeW, fe.rrotuncstpn; FeV, ferrovanadium; Felt, fermboron; FeCh, ferrocolumbium; NiCb,
nickel columbiunr. Si, silicon metal. FcCTi, ferrocarbontitanium.
- Includes Alsifer, Simanal, zirconium alloys, ferrosilicon boron, aluminum silicon alloys, and miscellaneous
ferroalloys.
C-3
-------
APPENDIX D
COPPER MINE PRODUCTION STATISTICS
D-l
-------
Table D-l UNITED STATES PRINCIPAL COPPER MINE STATISTICS/
CAPACITIES AND/OR 1972 PRODUCTION
United Slalet Principal Copper Mln.1 Slar.^ici— Riled Capacllic* and/or 1972 Production
Company 8 pro parly
name I location
Asarco
Siiver licit, Ai
Mission, Az
Anaccnrfa Co.
0-jtte. Ml. UG
Bulie. Ml. OP
6v«*. Mi, 111,
Vfrfloglon. Nv
Twin Suite*, Az
BagdjJ Copper Corp.
Bigdatf. Az
Cities Service Co,
CopporhW, Tn
Mraml. Az
CoDoe- P.ince Co.
Whit* Tine. Mi
Ouval Carp.
L-Epgrjrva. Ax
Mirtei*! Pnik
Bfftlle r/oL-niain. Mw
Si...'.,. p,?i Corp.
Bing'>.-.r. Ut
Puln, Nv
Chl-iO. NM
Ray, N*
Magma Czvi".'.' Cc.
Sjperioi. At
Ss^ Maruel. Az
Phe'p'j DfJ.rCnrp.
C.'j-pcr O-:,-."i, AiUG
Cc;i:v CM- -in. Ai OP
Mtiri'ncl, Ai
Tymnfl. MM
f i !*i.i . A /
qanrnn,. F»|1.or.11i
mi
1912
1959
1R7Q
ir>54
1942
19G9
1957
1964
SurlAc*
or
under.
ground
S
g
5
U
S
8
S
s
U
g
U
S
S
S
S
s
S
S
S
S
S
S
U
U
U
S
S
S
S
Reduction
plant
concen.
heap leacti
concert.
vnl leech
concen.
concen.
tieap leach
solv. exlrac.
elec. winning
concen.
•.matter
leach
heap leach
concen.
«meMer
concen.
heap leach .
heap le ach
ccncen.
heap teach
concen.
hfltfp IBflch
vat leach
smelter
elec. re I,
conctn.
heap [each
concen.
heap reach
smertor
«!ec. ret.
fljorite,
QIZ (J'OrMe
ichist.
qil. mom..
Quartzile
li.. primary
he^i.to,
pyrilc
porpfi.
qti. porph.,
l».
monz. r-'Orph,.
gian.!-. Is..
duftasp
,h>oli,.
qlt, mom.
metaied.
scWM.
gran He
cap.
Ipd.
10.500
!4,COO
32,000
6.00C
4.900
24.500
15.000
19.000
4.535
A3.00C
5,500
none
106,500
21,500
22.BOO
?5.400
4.000
62.500
19.000T1
—
60,000
46.000
53.500
no«»
'pr
,0,00
S3. 937
?»j.59Q
75.000
19.579
2i,ono
72.000
JO.2.5
16 3J2
68.940
53.M7
11.244
4.«4«
J5S.037
4S.OOO
75700
103.471
24.000
144 000
2S900
21. POO
'20,000
57.900
100,000
92500
7.500
Cu In
(p/ in c-cni
1->3uO -«
45 000 eS
P. 8. 26
18,500 M
75,000 Z9
12 279 32
2»,OCO 20
n.a. 31
17.024 25
08.940 26.1
25,347 39.24
11.244 20.43
— _
210.714 27 06
«!.000 115
5S.PGO !O.C
64.336 1fl
24,000 25
"4.000 28
16.60C 10.3
107.800 22.2
5J-.90C 30.3
96.000 21.3
32.500 2fl
— —
MOS;
Total Cu Cu iri pro due-
's lpr tpy
n.B 4.700 120'
n a 01 000
p. a. — 0
n.a. — 0
9' tt 24,000 0
n.B 20,000 0
n.a. 0 1,650
83 7 300' 38-J
n.a. 0 , 0
6.100
'
60.65 0 0
67 2,661 2.044
84.5 0 9.731
76 41 22.738 3rt>
71.g7 0 0
41.7 4.S4& 0
8907 n« 11.2S4
7Jj 3.000 1TO
79.3 n.t. 4?3
8? 14.&OQ 5^
frSS t> 0
92.7 0 4.JOO
69.3 5.000 0
792 12,200 0
94.6 0 0
77.5 4,000 0
85 0 I.500-
50 00
Product N«w »
cons _ (nspii alien. Ai none
ppls
fire lefmed maiket none
cona euitsni nprt
TDti smelt
rpU smelt
cons coHOiTi r.pre
sme
PP' markeJ 9 1 MM or*
c«t nodes
rod
tons InspifBtion nom
ppl Iftipiraiion ncne .^
calnodaa mirk*! r.ono
*n«des
r>pt>
blister Maryland none
pels
blister Tiauk-ijl none
Km refined
PPTS Maryland
anodes Hurley, NM none
cathodee
com San Manuel. A; I.QI MM ore
calhedes market none
dfrect rmjit.
^nodts P t). rcf-no none
nnodes P.O. /glint r-one
CCnj P.O. •melleri IQQ OQQ
ppls
com Douglmi norn
San Manuql. Az
c*!hod«i market 24,000*
**
, Con
a
7/1
1 9T
ien
.81
I'D
Ml
D-2
-------
APPENDIX E
LEAD PRODUCING MINES IN THE UNITED STATES
E-l
-------
Table E-l LEAD 1'KODUCING MINES IN UNITED STATES
td
PO
Aho , Go or'•_•;<->
American Smelting
Refining Co.
Antonioli, Peter
Bcbb, Virgil
Bunker Hill Co.
Bunker Kill Co.
3yrd, John H.
Byrd, John H.
Canyon Silver Mine
C1 i p p i? r M .1 n i rig Co .
C o H b s , M a r v i r. '• v.
Crim, John D.
Day Minos, Inc.
Dross c~ r I r. d u s t r i c s
Farrow Bros.
Gerlach, Keith H.
_ing &
- ri r-
:> .
3 .
M i n o s
' Co.
Tv .
. r ios
H .
N.".:1'-; OF MT-;E
f< j / '' . --T1 r-<: !
' ': i *- I ."• r ^ i " , '-'' "•••". "i i ! . '
Payo, Idaho
Mc-ni ton-Broadv/a t-.^r ,
Mop. t~ina
Douglas, Idaho
L u n her Hill,. I d a ' T o
Star, Idaho
S a ir, G a t y , Montana
Fran';] i n .- H o n t a n a
C a n y on S i 1 v e r , I d a h o
CM i ppcr , Colo .
L i ~ i n i t c , A r i z o n a
Henrietta, Colo.
Dayroc'-;, Idaho
Mag:ncnt, Mo.
Dia::io:.d Jim, I'-icvada
0 La" -..-;.•: J in , :]...-vruh':
n ; -1
M: . :'
A f ••
Pb,
Ag,
Ag,
Ag ,
Ag,
AU r
Au ,
Ag,
Ag ,
Ac; ,
Ag,
Ag ,
Pb
Au ,
P r-
INCIP.-..L
AFil- M ' ' . • , ! )
Di-,
Zn
Pb, Zn
Pb, Zn
Pb, Zn
Pb, Zn
Ag , Pb
Ag , Pb
Pb, Zn
Pb, Zn
Pb
Pb, Zn
Pb, Zn
Ag, Pb
0 RE
PRODUCTION
I'! ! Mf"T
1 '1
73,G93
S 4 0
ir.o
351,930
172,310
195
70
2,100
D o v e 1 o y ; ^ o n t onl y
34
290
23,715
116,120
360
D e v e i o c n e n t onl y
-------
COMPANY NAME
NAME OF MINE
& LOCATION
PRINCIPAL
METALS Mi:;ED
ORE
PRODUCTION
IN 1968
Hand, John
Helca Mining Co.
Helca Mining Co.
Helca Mining Co.
Hopkins, John F.
Kennecot Copper Corn.
Kraft Buildg., Contr.
Marshal Douglas
McBridge, G. V. R.
McFarland & Hullingcr
Mei ssnor, Dona Id O.
Minerava Oil Co.
Monte Cristo Mining
Corp .
Nygren, Rudy
Ivygren, Rudy
Osceola Metals Co.
Ozark Lead Co.
Hand, Montana
Star Morning, Idaho
Lucky Friday, Idaho
M a y f 1 o w o r , U t a h
Negros, Mont-ana
Eurgin, Utah
Treasure Key, Colo.
Santiago, Colo.
Montgomery, Montana
Iron King, Arizona
Goodvi cv/, Wevada
Jefferson, Illinois
Jubilee, Calif.
Ferdinand, Montana
Y e 11 o v; B i r d , M c n t a n L
Osceola, Colo.
Ozark. Load, Mo.
Au, Ag, P h
Ag, Pb, Zn
Ag, Cu, Pb, Zn
Ag. Cu, Pb, Zn
Ag, Pb
Ag , Pb, Zn
Pb
Au, Ag, Pb, Zn
Pb
Ag, Cu, Pb, Zn
Ag , P b, S b
Fluorspar, Pb, Zn
Pb
P b , Z n
Ag, Pb, Zn
Pb, Zn
Pb, Zn
2,050
172,310
87,020
111,000
29
181,440
92, 610
Development only
92,610
135
22,800
1 , 815
13
11
12,975
-------
Table E-2. MINE PRODUCTION OF RECOVERABLE LEAD IN THE UNITED STATES, BY
State
Va*k~
* •
l')\rin'<
K s
M ^- JO
1
1
1
2
45
3
5
1
68
W
704
001
778
790
467
227
W
611
,870
863
,3S3
396
387
W
,205
.573
.655
,126
140
19'
2,
21 .
65,
355,
1,
1
2,
1,
0
41
3
8
1
69
0
217
51 rt
767
597
791
395
452
753
420
368
686
605
1
332
,358
649
.102
19
1
21
61
1
421
3
1
(
45
3
6
70
285
,772
,855
,211
,532
80
,764
996
364
,550
280
797
3
.377
.356
,7R4
761
19
2
25
66
1
429
2
38
3
5
71
859
,284
,746
.610
,238
,634
615
111
.971
877
,270
.386
,177
752
20
Total 316.931 359,156 509,013 571.767 578,550
W Withheld to avoid disclosing individual company confidential data; included in "Other States."
' !-
-------
APPENDIX F
ZINC PRODUCTION IN THE UNITED STATES, BY STATE, 1971
F-l
-------
Table F-l PRODUCTION OF LEAD AND ZINC IN THE UNITED STATES IN 1971,
BY STATE AND CLASS OF ORE, FROM OLD TAILINGS, ETC.,
IN TERMS OF RECOVERABLE METALS
State
Idaho
New York . . . .
Utah
Other States
Total
1'ercent of total zinc-lead
Gross weight
(dry basis)
0)
. ... 311
4
172
. . 171
(>28
. . 4,244
614
413
.. - 281
6 843
.099
973
.027
74
,179
,533
.408
,715
,72i
425
.760
.955
869
Zinc ore
Zinc
content
32,239
69
265
10
29,977
15.585
27,438
111.992
16.829
8
10,645
11,190
266.247
51
Lead
content
3,612
22
30
3
3 . 386
752
486
8.291
2
Gross weight
(dry basis)
3,250
143
274.716
8.624,668
6.190
197
621
8,909,785
lx_-ad ore
Zinc
content
69
(')
2 , 506
4H.215
12
2
50 , 804
10
Xlnc-U-ucl ore
Lead
content
124
O
46
28.479
429.634
373
10
25
458,691
79
Gross weight
(dry basis)
i 8!)
425.
7HO
119.
606.
i 363,
252,
2 . 638 ,
042
,701
.970
217
532
.021
,978
,216
,492
174
7j\nc
content
1
i 3 , 003
16,084
41,854
"6
54
13,473
47,835
' 22,974
5,774
151,008
30
Lead
content
1
i 2,284
12.306
36.848
10
81
2.971
877
i 33 , 462
5.151
93,991
16
See footnotes at end o[ table.
-------
APPENDIX G
ALUMINUM, ALUMINA AND BAUXITE PRODUCTION STATISTICS
G-l
-------
Table G-l MATRIX OF THE CHARACTERISTICS OF PRIMARY
ALUMINUM PLANTS
bcdcrtrrt Pec-
*tr fqlliltlo* Cmuioi f.«tr*od»
d* ft*k* Anod« C*»t
fttdin. fjrih C*-v;:c.
K.;icr... Sr- V..I.
CuU CMSE
Uk« Ci-
loojv
275 23 201
US
' Ui
J3_
:t
'•'•° 10
_15 3_
50
NOTE: ST = Short ton
BOX U«; +
ESF Drv
UMC - recycle
X Drv
Ciy £2P
* "" Scry.E.'""-'
Wt
ia-p - once ^h^c^I^^
X "»
..Ij-"
"tt
Civolitt • IWcvcu''0
"« - -^«--
_Ei^
Pry
Closed
Sr.ter- SetlHr.t H.lni
Met tSP u«t
« Cr> "«I
tti
Cryo!it> - Recycle
None No*e
J BL»
^°"'•
Sor.< Nwe
Sa^hpuse None
» «»t «°»«
"°"« 2li Lirt - tfcrclt Ligoon
X Drv Ron* Kane
forte Mpne Drv
It Vtc Kon<
CrvolUe - Pe.vclr
J'V !•>'
G-2
-------
Table G-2 CAPACITIES OF DOMESTIC ALUMINA PLANTS,
DECEMBER 31, 1971
(thousand short tons per year)
Company ami plant Capacity
Aluminum Co. nf America: 375
Bauxite, Ark -------- ----- ...... • ----------------------------------------------- 1 yot
Monile. Ala ------ ..... ----------- ....... ------------------------------------------ j'35,,
Point Comfort, Tex -------------- ------------- .............. ------- ----------------- _______
Total - ________________ ------------------------------------ ........ -------------- "'350
Harvey Aluminum. Inc.: St. Croix, V.I . . . ---- --------------------- --- .......... ----- .._
Kaiser Aluminum & Chemical Cor|>: j 025
Baton liouee, I -a .. -------- ----------------------------------------------------- " ' x()0
G ra mercy, l-a ------ --------------- ------------------------ - --------------- ..... " _ .....
Total
Ormet Corp.: Burnsule, La
Reynolds Metals Co.; g40
Hurricane Creek, Ark --------------- ----- ----------------------------------- III "II 1 3X0
Corpus Christi, Tex ..... ...... -------------------------------------------------- __ 1. __
Total
Grand total
'Capacity may vary liepemlinn upon the bauxite being used.
G-3
-------
Table G-3 MINE PRODUCTION OF BAUXITE AND SHIPMENTS FROM
MINES AND PROCESSING PLANTS TO CONSUMERS IN THE UNITED STATES
(thousand long tons and thousand dollars)
Mine production
Alabama ;:
1971
Arkansas:
97.i.
i>7i
Tota Pni'.
f*i;<>
1!'71
' Com;.,.
> Data n
Crude
-, : Georgia:
108
. 110
... 270
261
1 943
1.901
2.251
2.157
i S' ates:1
2.051
2.071
2.233
2 . 522
2419
Dry
equivalent
83
S3
88
213
207
1.571
1 . 582
1.755
1 . HC9
1.781
i !<;<-,:,
1.843
2.0H2
1 .988
Value l
$810
694
1,020
3.778
3 , 564
18,269
23.058
24.706
26.293
24,979
19.079
23.752
25.725
30.070
28 . r>43
Shipment? from mines and
processing plants to consumers
As Dry
shipped equivalent
85
74
72
149
143
2.022
1.962
2 044
2.194
2, 161
2.107
2 . 036
2.116
2.343
2 . 305
84
69
79
161
171
1.742
1,680
1.765
1.917
1.892
1.826
1.749
1.R44
2 . 078
2.063
• <-• ; (rum ^eliinj; prices and values assigned by producers and from estimates of the Bureau
- i; i'.a for Oregon and Washington.
ay not add to totals shown because of independent rounding.
Value i
$1.236
K98
1,324
3,299
3,566
21.343
25.349
26 , 304
29 , 049
28.296
22.579
26.247
27.628
32,348
31.862
of Mines.
G-4
-------
APPENDIX H
TITANIUM CONSUMPTION (UNITED STATES) STATISTICS
H-l
-------
Table H-l CONSUMPTION OF TITANIUM CONCENTRATES
IN THE UNITED STATES, BY PRODUCT
Ilmen
Year and product Gross
weight
•'<• - 919
;.- - - . -_ . 9f>9
1,003
'i;t:ment*: 966
"V.anium metaL - _ _
V-VMm^-ri'd roatinga and fluxes
Vi.'vs arul carbide , '2,
Total . -. . ' 9G9
1 -merit* 890
"'V-J-.iin^-j-iHi coatings and fluxes
• '-.mii-s - _ (»)
Tutai - 896.
206
558
501
350
510
905
21
786
226
641
599
172
fi3S
ite i
Titanium slag
TiO,
content
estimated)
488
510
541
515
' 1
' 517
481
I
1
484
.236
,353
,840
,860
356
.320
13
,549
,141
474
.104
.714
.433
Gross TiOi
weight content
(estimated)
122,926
142 , KJH
138.553
129,247
C)
C)
129,247
147,191
m
--
147.191
8C,
100,
98,
91,
91,
104,
(')
104
945
591
075
639
639
375
375
Rutile
Gross TiOj
weight content
(estimated)
153,
160,
185,
140,
C)
15.
•31,
* 188.
191,
15.
(=)
20.
227.
457
273
432
790
634
79
391
112
006
786
113
403
605
907
147,
153,
178,
135,
14,
•29,
• 180,
183,
14.
(')
19,
218.
158
600
090
350
917
75
377
644
363
970
383
390
608
351
,
t.- a mixed product containing rutile. leucoxene, and altered ilmenite,
tM with "Miscellaneous" to avoi<( disclosing individual company confidential data.
ed Avith "Pigments" to avoid disclosing individual company confidential data.
H-2
-------
APPENDIX I
URANIUM MINING AND PROCESSING COMPANIES
1-1
-------
Table 1-1 U.S. URANIUM MILLING COMPANIES AND PLANTS IN 1971
Capacity
Company Plant location (tuns of ore
per day)
The Anaconda Co _ Bluewater, N. Mex 3,000
Atlas Corp Moab, Utah 1,500
Continental Oil Co.—Pioneer Nuclear, Inc . Karnes County, Tex '1. 7f>0
(Vtter Corp_ . Canon City, Colo ' 4i>0
Dawn Mining Co.. Font, Wash 5OO
Fe0
llumlile oil and Refining Co Powder River Basin, Wyo > 2,000
Kerr-MrGee Curp Grants, N. Mex 7.000
Mines Development, Inc. .; ... KdRemont, S. Dak ii50
1'etr, t, niit-s Co . Shirley Basin, Wyo 1, r,00
Uio AU,.in Mines, Ltd La Sal, Utah.. ' SOO
Su.Miiiphanna-Western. Inc Falls City, Tex 1 ,OOO
!>,., __ Ray Point, Tex 1,000
I'nii-n Carl'i'ie Corp lira van. Colo. 1 _ 2,000
;,,. Rifle, Colo. /
Do ........... Natrona County, Wyo l.OOO
Unitf-l \'iK-!eur Corp. Inc.—Homestake Mining Co Grants, N. Mex 3,500
ftali International Inc. Gas Hills, Wyo 1 ,W»
p, Shirley Basin, Wyo ! .200
\V(.-\,r!i Nut-lear. Inc Jeffrey City, Wyo 1,'JOO
31.900
; Vn'.ler r-jnatruction; planned completion in 1972.
Source: U.S. Atomic Knergy Commission.
1-2
-------
AND FABRICATING NUCLEAR FUEL MATERIALS IN 1971
Allied Gulf Nuclear Services. Inc
Allied Chemical Corp
Atomics International Div., North
American Rockwell Corp.
The Babcock and Wilcox Co
General Electric Corp
Do
Do... _
Gulf General Atomic Co..
Gulf United Nuclear Fuel Corp
Do - -
Do
Jersey Nuclear Co. .. . _....*...
Kerr-M i-Gee Corp
Do
NL Industries
Nuclear Chemicals and Metals Corp.
Nuclear Fuel Services, Inc
Do -
Nuclear Materials and Equipment
Corp, (NUMEC).!
Do
Nuclear Metals Div., Whiitaker
Corp
United Nuclear Corp
West) nnhoii.se Electric Corp ,
Do
Barnwi'll, S.C
Metropolis III X
Cano^a Park, Calif-.
LynchburK, V;i
Windsor Conn
M»>rrw, III
Sun Jose ami
Valient,*, Calif.
Wilmington, X'.C.
Kan Du'>ro. Calif
Klmrtfont and
Pawling, X.Y.
Hematiu,-, Mo.
New Huvvn, Conn
Richlund, Wash
Cimarron. Ok la
Albany. \.V
Huntsvilli-, Tenn
Krwin, Tpnn
West \alk-y. N.Y
Apollo. Pa
Let'chburn, Pa
West Concord Mass
Wood RIVIT Junction.
R.I.
Oht.-swirk, Pa, ....
Culumbiu, S.C ,
1'O-i
' X
1 X
X
X
X
X
' X
X
X
X
x
X
uo-
' X
X
X
X
X
X
X
X
X
X
X
t;o.
X
X
X
X
X
X
X
X
' X
X
X
X
X
Fuel
fabrication
Car- Spocial
hide
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
x
U-2.1H Pu
X
X
1 X
X
> X
X
X
X
X X
' X
X X
X
Dtpleti.-d
uranium Scrap
Metal Com- U
pimmls
X
'X
X
X
X
X
X
'X
XXX
X
X 'X
XXX
X X
X
X X
X
_
1 X
Pu
' X
' X
i X
' X
1 X
X
X
X
X
'-
Spent En-
fuel richer!
cluing UFi
'X IX
'X 'X
_ .
. _
- -
X 'X
X
- -
--
--
X FrulicaU'ft capacity shown.
1 Under construction or planned.
: Formerly an Atlantic Kirht'iuUi Oil Co. subsidiary; facilities acquire.d by Babcurk and Wilcox Co. in Nuvrmbi-r.
Suurct*: lr.S. Atomic KiHir(fy Commission.
-------
TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
1. REPORT NO.
EPA-650/2-74-115
2.
3. RECIPIENT'S ACCESSIOWNO.
4. TITLE AND SUBTITLE
Trace Pollutant Emissions from the Processing of
Metallic Ores
5. REPORT DATE
October 1974
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
V.Katari, G.Isaacs, and T.W.Devitt
8. PERFORMING ORGANIZATION REPORT NO.
PEDCO-3146E
9. PERFORMING ORGANIZATION NAME AND ADDRESS
PEDCo-Environmental Specialists, Inc.
Atkinson Square (Suite 13)
Cincinnati, Ohio 45246
10. PROGRAM ELEMENT NO.
1AB015: ROAP 21AUZ-02a
11. CONTRACT/GRANT NO.
68-02-1321 (Task 5)
12. SPONSORING AGENCY NAME AND ADDRESS
EPA, Office of Research and Development
NERC-RTP, Control Systems Laboratory
Research Triangle Park, NC 27711
13. TYPE OF REPORT AND PERIOD COVERED
Final; Through 8/74
14. SPONSORING AGENCY CODE
15. SUPPLEMENTARY NOTES
is. ABS RACT
repOrt gives results of a. study of eight metallic ore processing indus-
tries. Selected for their potential for hazardous pollutant emissions, the industries
.were: iron and steel, ferroalloy, primary copper, primary lead, primary zinc,
aluminum, titanium, and uranium. Bases for selection were: quantity of ore pro-
cessed, toxicity of potential emissions, fugitive dust emissions potential, and
process characteristics. The report describes the processes in each industry
in terms of a functional process statement, process operating conditions, energy
requirements, potential emissions, and method of transferring material from one
process to the next. Eleven processes are recommended for more detailed study
because of their significant hazardous pollutant emissions potential.
17.
a.
Air Pollution
Metalliferous
Minerals
Beneficiation
Dust
Toxicity
KEY WORDS AND DOCUMENT ANALYSIS !
DESCRIPTORS
Fuels
Furnaces
Trace Elements
Waste Disposal
Water Pollution
18. DISTRIBUTION STATEMENT
Unlimited
b.lDENTIFIERS/OPEN ENDED TERMS
Air Pollution Control
Stationary Sources
Particulates
Energy Requirements
Mineral Mining
Mineral Processing
19. SECURITY CLASS (This Report}
Unclassified
20. SECURITY CLASS (This page}
Unclassified
c. COSATl Field/Group j
13B, 21D |
13A E
08G, 06A |
11F, 081 |
06T j
21. NO. OF PAGES |
282 |
22. PRICE 5
I
5:
EPA Form Z220-1 (9-73J
1-4
------- |