EPA-600/2-76-167
June 1976
Environmental Protection Technology Series
METALS MINING AND MILLING PROCESS
PROFILES WITH ENVIRONMENTAL ASPECTS
Industrial Environmental Research Laboratory
Office of Research and Development
U.S. Environmental Protection Agency
Research Triangle Park, North Carolina 27711
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RESEARCH REPORTING SERIES
Research reports of the Office of Research and Development, U.S. Environmental
Protection Agency, have been grouped into five series. These five broad
categories were established to facilitate further development and application of
environmental technology. Elimination of traditional grouping was consciously
planned to foster technology transfer and a maximum interface in related fields.
The five series are:
1. Environmental Health Effects Research
2. Environmental Protection Technology
3. Ecological Research
4. Environmental Monitoring
5. Socioeconomic Environmental Studies
This report has been assigned to the ENVIRONMENTAL PROTECTION
TECHNOLOGY series. This series describes research performed to develop and
demonstrate instrumentation, equipment, and methodology to repair or prevent
environmental degradation from point and non-point sources of pollution. This
work provides the new or improved technology required for the control and
treatment of pollution sources to meet environmental quality standards.
EPA RE VIEW NOTICE
This report has been reviewed by the U. S. Environmental
Protection Agency, and approved for publication. Approval
does not signify that the contents necessarily reflect the
views and policy of the Agency, nor does mention of trade
names or commercial products constitute endorsement or
recommendation for use.
This document is available to the public through the National Technical Informa-
tion Service, Springfield, Virginia 22161.
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EPA-600/2-76-167
June 1976
METALS MINING AND MILLING
PROCESS PROFILES
WITH ENVIRONMENTAL ASPECTS
by
R.J. Nerkervis and J. B. Hallowell
Battelle-Columbus Laboratories
505 King Avenue
Columbus, Ohio 43201
Contract No. 68-02-1323, Task 35
ROAPNo. 21AFH-025
Program Element No. 1AB015
EPA Task Officer: W. G. Tucker
Industrial Environmental Research Laboratory
Office of Energy, Minerals, and Industry
Research Triangle Park, NC 27711
Prepared for
U.S. ENVIRONMENTAL PROTECTION AGENCY
Office of Research and Development
Washington, DC 20460
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METALS MINING AND MILLING PROCESS PROFILES
WITH ENVIRONMENTAL ASPECTS
TABLE OF CONTENTS
Page
INDUSTRY DESCRIPTION 1
A. Metal Industry Segment Sizes, Major
Participating Companies, and Localities 1
B. Raw Materials and Products 3
C. Environmental • Impacts 7
1. Atmospheric Emissions 8
a. Open-Pit Mining 8
b. Underground Mining 9
c. Crushing, Grinding, and Classifying 9
d. Drying Process-Stream Materials 9
e. Roasting and Calcining 10
2. Emission of Liquid Wastes 10
a. Open-Pit Mining 10
b. Underground Mining 11
c. Placer Mining 12
d. Crushing and Screening 12
e. Crushing, Grinding, and Classifying 12
f. Gravity Concentration 13
g. Flotation 13
h. Magnetic Concentration 13
i. Leaching 14
j. Solution Extraction 14
k. Tailings Ponds and Reservoirs 15
3. Emission of Solid Wastes 15
a. Open-Pit Mining 17
b. Underground Mining 17
c. Placer Mining 18
d. Gangue Minerals—Tailings. 18
e. Leach Residues 19
f. Miscellaneous Solid Wastes 19
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METALS MINING AND MILLING PROCESS PROFILES
WITH ENVIRONMENTAL ASPECTS
TABLE OF CONTENTS (Cont.)
Page
4. Overview 19
D. References. 21
II. .INDUSTRY ANALYSIS 21
A. Aluminum 24
B. Antimony 36
C. Beryllium 44
D. Copper 57
E. Gold. . . . 96.
F. Iron. 129
G. Lead and Zinc 155
H. Mercury 166
I. Molybdenum 183
J. Nickel 195
K. Platinum Group Metals 201
L. Rare Earth Metals 205
M. Silver. 215
N. Titanium 225
0. Tungsten 240
P. Uranium 252
Q. Vanadium 270
III. APPENDICES
A. Population of U.S. Metal-Mining
and Beneficiation Companies A-l
B. Raw Materials, Minerals, and Products Utilized
in Metal-Mining and Milling Industry. . . B-l
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METALS MINING AND MILLING PROCESS PROFILES
WITH ENVIRONMENTAL ASPECTS
INDUSTRY DESCRIPTION
U.S. industries engaged in the mining of ores for the production of
metals are identified as major group 10 in the Standard Industrial
Classification (SIC) Manual, 1972, published by the Executive Office
of the President (Office of Management and Budget). This industry
category includes establishments engaged in mining ores for the pro-
duction of metals, and includes all ore dressing and beneficiating
operations, whether performed at mills operating in conjunction with
the mines or at mills operated separately. These include mills which
Crush, grind, wash, dry, sinter, or leach ore, or perform gravity
separation or flotation operations.
The industry categories covered by this report include the following:
SIC 1011 - Iron Ores
SIC 1021 - Copper Ores
SIC 1031 - Lead and Zinc Ores
SIC 1041 - Gold Ores
SIC 1044 - Silver Ores
SIC 1051 - Bauxite Ores
SIC 1061 - Ferroalloy Ores
SIC 1092 - Mercury Ores
SIC 1094 - Uranium/Radium/Vanadium Ores
SIC 1099 - Metal Ores, Not Elsewhere Classified.
The various metal values covered in these SIC codes are shown in Table
I. Twenty-three categories have been identified as commercially
important. Of these, seventeen are analyzed in this report. Two more,
thorium and zirconium, occur as byproducts and are analyzed in con-
junction with the principal metallic ore. The remaining four,
chromium, columbiurn-tantalum, manganese, and tin are almost wholly
imported and thus do not come under the scope of this study.
Metal Industry Segment Sizes,
Major Participating Companies,
and Localities
Industry segments vary drastically in size. Table I shows the produc-
tion and consumption data of metal values in the U.S. Iron and steel
is by far the largest. Aluminum is second in consumption, lead and
1
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TABLE I. SUMMARY OF PRODUCTION AND CONSUMPTION DATA
(U.S. METAL-MINING INDUSTRY PRODUCTION
VERSUS TOTAL U.S. METAL CONSUMPTION
Metal
Aluminum
Antimony
Beryllium
Columbium-
Tantalum
Copper
Gold
Iron
Lead
Zinc
Manganese
Mercury
Molybdenum
Nickel
Platinum
Rare earths
Silver
Thorium
Tin
Titanium Oxide
Titanium
Tungsten
Uranium Oxide
Vanadium
Zirconium
Zircon
U.S. Ore
Production,
Millions of
Short Tons
. ' 2.07
no data
no data
no data
. « 280
6.6
209
~ 10
~ 10
0.23
0.08
20
no data
no data
~ 1
no data
no data
-25
none
0.74
~ 7
no data
none
no data
U.S. Metal Primary
Production From
Domestic Ores,
Millions of Pounds
1,040.00
1.30
~ 0.50
3,600.00
0.089
120,000.00
1,510.00
1,000.00
60.00
0.904
112.00
30.00
~ 0.00i(b)
27.40
3.117
mm
0.220.
1,540.00
—
3.50
28.00
—
—
250.00
U.S. Metal
Consumption
(all sources)
Millions of Pounds
15,600.00
79.00
0.624
4.00
6,800.00
0.524
180,000.00
3,100.00
3,040.00
3,800.00
4.060
57.00
390.00
0.116
27.40
15.417
0.300
124.00
1,674.00
42.00
7.75
• 24.00
10.60
6.00
380.00
U.S. Metal
Production/
Consumption
Ratio, 7.
- 7
1 to 2
80
mm
~ 53
17
66 •
~49
- 33
1 to 2
22
196
7 to 8
~ 1
100
20
mm
< 1
92
0(c)
45
117
—
0(c)
66
(a) Copper from secondary recovery would increase this ratio to about 95 percent.
(b) About 1,164 pounds.
(c) All ore for metal production was imported.
(d) Production and consumption on a U.00 basis.
j o
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zinc are next (the consumption of manganese is slightly larger than
lead and zinc, but 98 percent of manganese ore is imported). Tita-
nium oxide and zircon account for considerable domestic tonnage
production. The only other metal produced in amounts in excess of
45.4 million kilograms (100 million pounds) annually in the U.S. is
molybdenum.
There are currently about 200 readily identifiable companies in the
U.S. participating in the recovery and beneficiation of ores for
metal production. It is estimated that there may be as many as 100
to 150 additional companies that are small and/or are operating inter-
mittently, or that participate less directly in ore recovery (e.g.,
exploration and construction, excavation, and transportation companies)
The number of major participating companies for each of the metal
segments of the industry (again on the basis of the primary metal pro-
duction) are given in Table II. Selected prominent company names are
included in this table, whereas more complete listing of participating
companies is given in Appendix A. Figure I is a map of the continental
United States dipicting the approximate locations of the major metal-
mining operations. There are approximately 250 mining sites shown
which account for the bulk of the U.S. production.
Raw Materials and Products
The major raw material in a metal-mining and benefi dating operation is,
of course, the ore body. An ore body is a mineral deposit which, under
current economic and technological conditions, can be exploited for the
recovery of its valuable minerals at a possible profit. Usually, there
is a dominant mineral or an assemblage of minerals of a dominant metal
in an ore body, although the importance of coproduct and/or byproduct
metals cannot be overstated. "Mine evaluation, process selection, in
fact, ore deposit economics leading to decisions to open a mine can be
ultimately based on the presence and recoverability of byproduct metals."*
Thus, as shown in Table III, several metals are apt to be the target of
operations at a single site in the U.S. practice. The basic raw material
is nevertheless the mineral or minerals for a dominant metal. Table I in
Appendix B lists the ore deposit names and the principal minerals being
mined in the U.S. for the metals of SIC 10 included in this study. The
names of the beneficiated products resulting from U.S. mining operations
also are given in Table I, Appendix B.
In addition to the ore deposit as the principal raw material for a mining
operation, there are usually a host of other materials required. For
example, blasting materials (explosives) are used in most mining opera-
tions. Drilling and loading equipment requires fuel and lubricants, and,
in numerous cases, wooden timbers and other construction materials are
used in mine support, as well as in building mine entrance, access, and
equipment storage structures. The equipment for mined ore transport
requires fuel and lubricants.
Mr. Edward R. Bingham, Manager, Environmental Affairs, Copper Range
Company, Michigan
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TABLE II. THE NUMBER OF READILY IDENTIFIABLE COMPANIES
PARTICIPATING IN THE U.S. HETAL ORE PRODUCTION
Metal Symbol Number of
used in Participating
Figure 1 Companies (a)
Aluminum
Antimony
Beryllium
Columbium-
Tantalum
Copper
Gold
Iron
Lead-Zinc
Managanese
Mercury
Molybdenum
Nickel
Platinum
Rare Earths
Silver
Thorium
Tin
Titanium
Tungsten
Uranium
Vanadium
Zirconium
i/. . , . ,-r-^.a :
A
--
B
C
G
I or •
L
--
H
M
N
--
R
S
—
—
T
V
U
V
Z
10
2
5
(1)
32
12
35
28
(3)
4-5
2
1
1
2
14
(5)
(1)
7
10
24
1
(3)
Selected Company Names (b)
Alcoa, Reynolds
Heel a, Sunshine
Brush Wellman, Berylco
(Byproduct production) Curtis Nevada Corp.
Anaconda, Cities Service, Kennecott, Hecla,
U.V.
Carlin, Homes take, U.V. Industries
Cities Service, Cleveland Cliffs, Hanna,
U.S. Steel
AMAX, Bunker Hill, Kennecott, St. Joe, N.J.
Zinc
(Byproduct production) Hanna, N.J. Zinc
All very small companies (Placer Amex Co.
start up in 1975) (c)
Climax Molybdenum (Div AMAX), Molycorp.
Hanna Mining Company
Goodnews Bay Mining Co. (Alaska)
Molycorp, Curtis Nevada Corp.
Bunker Hill, Hecla, Sierra Silver-Lead,
Sunshine
(Byproduct production) Humphreys Eng. ,
du Pent
(Byproduct production) Climax-Molybdenum
(Div AMAX)
Glidden-Durkce, Humphreys Eng. , du Pont,
N.L. Industries
General Electric, Mines Exploration,
Rawhide, U.C.
Anaconda, Atlas, Exxon, Kerr-McGee,
Ranchers, U.C.
U.C. (i.e., (Union Carbide)
(Byproduct production) Humphries, du Pont
la)
(b) Sec Chapters VII through XXVII for complete names and locations
(c) Large and new producer.
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H-Hg, M-Mo, N-Ni, R-RE, S=Ag, T-T1, W-W, U-U,
FIGURE I. LOCATION OF THE PRINCIPAL METAL-MINING ACTIVITIES III THE CONTINENTAL UNITED STATES
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TABLE III. CLASSIFICATION OF SELECTED METALS MINED
IN .THE UNITED STATES
Group A
Principally Single J-ictal
Production
Group B
Metals Mined as Principal,
Coproduct or Byproduct
Values
Group C
Metals Mined only as
Coproduct or Byproduct
Values
Aluminum Al
Beryllium Be
Boron B
Magnesium Mg
Mercury Hg
Nickel Ni
Silicon Si
Iron Fe(c>
.
•
. •
Copper
Antimony
Gold
Iron
Lead
Molybdenum
Platinum Group
Rare-Earth Group
Silver
Titanium
Tungsten
Uranium
Vanadium
Zinc
Cu
pt
RE
Ag
T1(d>
V
U
Columbium Cb (Ta)
Manganese Mn
Radium Ra
. Tin Sn
Thorium Th
Zirconium Zr
(a) Some byproduct pallium.
(b) Coproduct gold from some ore. Byproduct mercury from some zinc ores.
(c) Coproduct tranyanccc or titanium from some ores.
(d) These elements might be considered as subgroup B-l, metals commonly mined
as principal value, balance as subgroup B-2, metals seldom mined as
principal value.
(e) Not currently recovered for resale.
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Beneficiation operations take their share of raw materials too, ranging
from simply the fuel to run sizing equipment to a host of materials
required for the more sophisticated physical and chemical separations.
Various conditioning chemicals such as zinc sulfate, lime, sodium
sulfide, zanthates, phosphates, oils, and flocculating agents are used.
Table II in Appendix B summarizes the raw materials used in mining and
beneficiation and includes typical flotation reagents.
A very important raw material consumed in many beneficiation operations
is steel, particularly that used in grinding. For example, the copper
segment uses about 0.75 kg (1.5 Ib) of steel in grinding balls and
vessel liner per metric ton (short ton) of ore. This amounts to over
181,400 metric tons (200,000 short tons) of steel per year for just
the copper segment of the industry. In cost, this can" equal the cost
of flotation reagents. Steel consumed in grinding, crushing, drilling,
and loading operations is a significant raw material expendable.
Another raw material, water, is used at the rate of 4 tons per ton of
ore in copper beneficiating. While maximum possible recycle of water
is.practiced, water consumption via evaporation loss, etc., is also a
significant raw material expendable.
The products of the U.S. metal-mining industry as indicated in Table I
in Appendix B may range from a metallic product (e.g., mercury and crude
gold bullion) to a run-of-mine ore (e.g., a rich iron ore), or to lean
ore concentrate. Beneficiation operations of some type are currently
used in every U.S. mine to supply a product which is suitable for sub-
sequent ore reduction and metal-winning operations. The concentrates
can vary in their value content from low (e.g., 11 percent BeO in a
beryl concentrate) to high (e.g., crude gold from retorting an amal-
gamated concentrate). Further, a concentrate product may contain
several metals which will not be separated one from the other until a
later processing step which is not a part of the beneficiation process.
On the other hand, some beneficiation operations achieve a separation
of mineral species as an integral part of the concentrating operation.
Environmental Impacts
The U.S. metal-mining and beneficiating industry handles a large volume
of a variety of materials, mostly rock, in a wide range of process steps.
Emissions from the materials and processes can be a problem. In addition
to emissions, other types of environmental disruptions are associated
with mining and beneficiation activities. The general characteristics
of emissions and environmental problems of the industry are described in
this section.
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The raw materials and processing steps which constitute the core of the
mining and beneficiating industry are described in detail in the indivi-.
dual metal-industry segment flowsheets. Generally, emissions from simi-
lar processing steps in the various segments of the industry are essen-
tially the same from one segment of the industry to another. Therefore,
the arrangement of the process descriptions in this section is presented
in a manner to serve for all segments having common process steps.
Atypical emissions from common process steps are noted in the individual
industry process descriptions where variations in materials or processes
lead to uncommon conditions. Also, for industrial segments utilizing
uncommon process steps, descriptions of emissions from such steps are
noted in the process descriptions.
Atmospheric Emissions - Emissions from the mining and beneficiating
processes to the atmosphere may consist of either or both particulate
and gaseous materials, some of which may be hazardous to health. The
physical nature and the chemical composition of the atmospheric emis-
sions depend to some extent on the segment of the industry from which
the emissions are derived. On the other hand, the commonality of emis-
sions from the various process steps that are common to several segments
is great and these characteristics are described in the following sub-
sections.
Open-Pit Mining. Some portion of the atmospheric emissions from this
process step comes from the consumption of fuel providing energy for the
mining equipment. Drilling and loading equipment, as well as auxiliary
transport equipment, contribute to the total emissions.
Explosives and their abundant use in blasting operations associated with
open-pit mining contribute to atmospheric emissions. Hydrocarbons may be
used as explosives extenders. Commonly, ammonium nitrate is also used in
conjunction with primary explosives for maximum ore breakage per unit of
explosive. For example, up to one-sixth kilogram of explosive per metric
ton (one-third pound of explosive per short ton) of ore is used in a
typical pit mining operation. Generally, the explosives emissions are
the oxides of nitroaen of several soecies. While not an enimission oer se
and therefore not elsewhere described in this report, the environmental dis-
turbance of blasting noise may be a oroblem under particular circumstances.
Many open-pit mining operations are conducted under dry conditions, essen-
tially year round in semiarid districts, and periodically in the dry sea-
sons of wetter climates. Dust as an emission to the atmosphere commonly
occurs, and a universal range for its occurrence on a quantitative basis
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is 0.25 to 0.51 kilograms per metric ton (0.5 to 1.02 pounds per short
ton) of ore. It is not a problem in the open-pit mining of naturally
wet ores (e.g., nickel ores at Riddle, Oregon), and it can be con-
trolled to some extent by water spraying under the drier operating
conditions. In some operations, the ore is of such a nature that it
does not readily dust even under dry conditions.
Underground Mining. Fumes from fuel consumption in mining equipment
operation contribute to the atmospheric emissions from underground min-
ing. No quantitative data are available to indicate compositions and
quantities of fumes attributable to this source. However, it is known
that there are oxides of nitrogen in underground mine fumes from the
use of explosives. Fumes or gases also might emanate from the mining
operation per se in the form of hydrocarbons (e.g., methane) sulfides
(e.g., H2S), and others. Radon gas is a problem in some underground
uranium mining operations. All of the mine gas is brought to the
surface via the ventilating systems and may be dispersed to the atmo-
sphere without good control. The average particulate content of venti-
lated underground mine gas discharges is 0.05 kilograms of dust per
metric ton (0.1 pound of dust per short ton) of ore mined. The parti-
culates are generally large and may be precipitated in the vicinity of
the mining activity.
Crushing, Grinding, and Classifying. Crushing as an initial process
step in preparing mined ore for additional beneficiation can give rise
to large quantities of dust to the atmosphere. [The emission factor
for crushing is up to 3.75 kilograms of particulates per metric ton
(7.5 pounds of particulates per short ton) of ore.] Quantities of dust
generated in this step may vary with rock type and moisture content of
the ore. Crushing is usually followed by grinding. Both rod mills and
ball mills may be used in grinding with both types usually being oper-
ated wet in closed circuits with classifiers. Classifiers are of
various types which send various size ranges of crushed and ground ore
on to different circuits. For example, oversize material might be re-
cycled or discarded, properly sized material might be sent on to the
next process step, and undersize material might be sent to a special
materials handling circuit. If accomplished as a wet operation in a
closed system, there is no dust problem. If it is a dry system, dust
emissions to the atmosphere from screening can be high [e.g., 38 kilo-
qrams per metric ton of feed (76 pounds per short ton) of feed] but
controllable (e.g., via baghouses). Further, the grinding of rocks,
either wet or dry, can result in the release of rock gases of various
species and these may be vented to the atmosphere.
Drying Process-Stream Materials. Several process steps used in bene-
ficiating metal ores are accomplished in water slurries and, in other
cases, precipitates are obtained from aqueous solutions. Frequently,
-------
such wet processing requires further processing in the dry state and for
this the process-stream material or the precipitate must be dewatered
and dried. Cyclone equipment, drum filters, etc., may be used to dewater
with the possibility of producing liquid waste effluents. The dewatered
pulp or precipitate may be dried in ovens, rotary furnaces, multiple-
hearth furnaces, etc. Emissions to the atmosphere from drying usually
consist of only water vapor and coarse particulates (in contrast to
reaction products such as gases, fume, etc.). The emissions are gener-
ally amenable to control by standard control techniques, i.e., hot pre-
cipitators, baghouses, or, less likely, wet scrubbers.
Roasting and Calcining. Process-stream material may be reduced or chemi-
cally altered in the presence of another added material (e.g., salt
roasting) or oxidized and/or fritted or physically altered in form by
heating (e.g., calcining). These so-called roasting or calcining steps
involve a high energy input to the ore. Furnaces of various types are
used. Both fumes and particulates may be released to the atmosphere.
For example, in roasting operations, emissions to the atmosphere may
contain fuel combustion products from natural gas, oil, coke, or coal,
and reaction products such as the gasses CO , SO , FUS, NO , etc. Par-
ticulate emissions will include not only the coarse particles lost from
the process material but also so called fume, characterizable as particu-
lates which are chemical reaction products condensed from the gas phase—
submicron metal oxides, for example. Emissions of this kind may be con-
trolled by the use of electrostatic precipitators, baghouses, or wet
scrubbers. The recovery of discharge material from roasting or calcining
process steps may be required to prevent unacceptable metal losses which
would otherwise occur (e.g., in the case of nickel ore processing).
Emission of Liquid Wastes - Natural water is frequently encountered in
mining operations and it may become contaminated with mine chemicals.
Also, large quantities of water are used in processing metal ores. As
cited previously, about 4 kg of water are used per kg of ore in some
segments. Wastewaters containing very large levels of suspended (e.g.,
asbestiform gangue minerals) and dissolved (e.g., cyanide salts) solids
may be produced. The composition of these emissions often may be unique
to particular locales or to particular metal segments of the industry.
However,, there is a commonality of liquid waste emissions from several
process steps which is described in the following subsections.
Open-Pit [lining. The major effluent problem associated with open-pit
mining is acid mine drainage. The disturbed rock of some ore deposits,
10
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their overburden, and the surrounding country rock may give up chemicals
to the natural water drainage system of the locale. For example, sulf-
ide minerals of many species, but most commonly pyrites (iron sulfides),
may be exposed in open-pit mining with the result of sulfidizing (i.e.,
acidifying) the drainage waters. Control of this kind of emission may be
nonexistent or extensive. An example of the latter is the 45,000,000
liters per day (12,000,000 gals/day) lime and settling water treatment
plant in operation at one bauxite mine. Under proper operating condi-
tions, the acid discharge to the local water system is negligible. In
semiarid localities, the problem may be nonexistent owing to lack of
water and essentially no drainage.
The inescapable operational factors which must be recognized here are the
magnitude of the volumes of overburden and ore which are moved. The
stripping of overburden, exposing oxidizable minerals to the air, often
results in waste piles of a size approaching major features of the terrain
(i.e., mountains) and the depth of the pits may well involve cutting
through one or more natural aquifiers. Thus, control of natural runoff
water (rain) or the pumping of mine water necessary to maintain working
conditions at the lower level of the pit involve considerations on the
scale of miles or handling the entire output of an aquifier. A recent
example of such an exercise was completed in an open-pit copper mine in
Arizona where expansion of the pit into new areas of the ore body
involved the diversion of a natural water course including a sizable dam
and the cutting of a 2.4 kilometer (1-1/2 mile)" tunnel.
In addition to water contamination by rock chemicals due to earth distur-
bance, there is the possibility of wastes being emitted to the water from
other materials. For example, fuel and oil spills or discharges are a
possibility. Also, explosives contribute a high nitrogen discharge to
the drainage waters which can result in downstream algae blooms, etc.
Underground Mining. Underground mining operations may give rise to an
acid mine drainage problem also. The layout of some mines in their topo-
graphical setting may allow a natural drainage to lower slopes and, in
some cases, ground water from higher slopes might actually percolate
through the ore before exiting at lower slopes. In wet mines where
natural drainage is inadequate, mine waters are pumped to the surface.
The minerals of the ore body and the country rock may give up soluble
constituents to the waters. Sulfides are undoubtedly the most frequent
problem. The acidity of discharge waters can be quite high. Control is
always difficult and expensive especially in cases of high-volume
discharge.
The volumes and nature of mine water are always unique to the individual
underground mine. Mine water may vary in nature from high quality drink-
ing water to highly silted (high suspended solids) water with chemical
11
-------
characteristics varying from acid to alkaline, depending on the mineral
and/or rock matrix. The use of explosives, an absolute requirement in
hard-rock underground mining, contributes to a high nitrogen content of
the discharge mine waters.
Placer Mining. There are various methods of placer mining and all require
copious quantities of water. Depending largely on the nature of the
deposit, hydraulic methods (pressure streams and sluicing), dredges, or
other techniques.might be used. Deposits can range from stream-bed
gravels to bank-run silts that might be remote from present stream or
beach. Dredges might work entirely within an existing water body or a
working pool might be created which migrates with the pace of mining.
The major emission problem that is usually associated with placer mining
is the silting of discharge waters. Fuel spills may contribute to the
liquid waste problem. If blasting is used (e.g., it is used in southern
Georgia titanium placer mining operation), it may contribute to a high
nitrogen discharge to adjacent waters. Exposure of previously buried
rock formations may result in oxidation and erosion of otherwise stable
rock formations. Another environmental problem that can be associated
with placer mining of stream deposits is channelization of the stream
bed—potentially damaging in itself to the native ecology of the stream.
Crushing and Screening. Crushing operations are usually a dry process
and may or may not require and have dust control equipment in association.
If wet scrubbers are used to control particulate'emissions, the scrubber
water may be included in the plant water system, usually passing through
the tailings pond before recycle. The water burden from the scrubbers
may discharge in the tailings pond and from the pond may discharge to
the local area drainage—in due course.
Screening and washing operations (if screening is accomplished wet)
similarly may use water from the plant system and discharge some portion
of the mined ore to the tailings pond. Commonly, silts, clays, and
undersize ore fractions are separated from the desired ore fraction and
are discharged to the waste water system.
Crushing, Grinding, and Classifying. Usually, water is introduced in
the grinding operation of the beneficiation system, and acts as a
vehicle for the transport of ground ore. Conditioning chemicals may be
added, even in the grinding step. Unwanted ore fractions (e.g., clays)
may be separated in the classifiers and discharged via the water system
to the tailings pond. The waters thus may carry a waste emissions burden
which may or may not be controlled in the pond.
12
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Gravity Concentration. Most gravity concentrating systems are operated as
wet processing steps utilizing water as the ore carrier. Additives such
as heavy media compounds (e.g., ferrosilicon) may be used to facilitate
the separation functions of this concentrating method. In many wet
gravity concentrating systems, closed circuits are utilized wherein the
gravity equipment is in series with another concentrator such as flota-
tion cells. In other gravity systems, only gravity concentration is used
to separate the value minerals from the gangue, discharging the gangue
tailings to the reservoir pond. Here the tailings may be discharged and
the conditioned water recirculated. In operations located near large
bodies of water, tailings water may not be recycled. Thus, there are two
possible liquid waste emission problems: one associated with tailings
pond water control and the other with discharge of waters contaminated on
a once-through basis.
Flotation. The flotation concentrating method requires large volumes of
water which is conditioned with a variety of chemical compounds to achieve
the ore particle float-no float phenomena. Examples of the chemicals used
are given in Table II in Appendix B, and these are added to serve the
functions of dispersant, collector, promoter, frother, and flocculant in
the flotation process step. Usually, there are several banks of flotation
cells in a rougher concentrating, cleaner, and recleaner sequence. Separa-
tions of value minerals from gangue and of one type value mineral from
another are achievable in essentially closed systems. However, gangues
are carried to and discharged in ponds. Dewatering systems (e.g., cyclone
thickeners or filters) in the circuit may thicken the discard routed to
the pond and overflows of substantially clear water (altered with residuals
of the additives previously mentioned) may be recirculated. Needless to
say, the tailings ponds receive an adulterated water burdened with sus-
pended solids and dissolved materials and the control of this waste from
flotation systems is required.
Magnetic Concentration. This concentrating-separating method may be accom-
plished either in the wet or dry state, on either belt- or drum-type
equipment, and either singly or in combination with other concentrating
equipment. Wet magnetic concentrating systems always have the potential
of adding a waste rock burden to the water vehicle, even in cases where
both fractions of the magnetic separation are to be subsequently processed
in additional steps. Water soluble constituents of the ore and gange
minerals to be discarded are the burden carried to the water reservoir of
the system. Discharge of the burden in the pond facilitated by chemical
treatment in some cases and by physical means (settling) permits water
recycle. The process step has an emissions potential which may require
careful control in some cases.
13
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Leaching. The specific.liquid wastes obtained from the various metal ore
leaching processes are described in the individual metal segment flow-
sheets. Several types of leaching media are used, depending on the ore.
For example, water leaching is used to extract vanadium, acid leaching
(sulfuric) for copper, salt solution (sodium cyanide) for gold, and
alkali (carbonate) for uranium. In each case, leaching solutions are
carefully guarded against loss since they contain the value mineral.
Nevertheless, accidental spills of leach liquors are possible, particu-
larly in cases where large volumes of liquid are involved and spills may
mean liquid waste emissions to the local drainage system or ground waters.
In addition to spills, spent leaching solutions-may be discharged to hold-
ing reservoirs. The solutions may become inefficient due to the buildup
of various salts, in which case they may be ponded for rejuvenation or
for eventual discard. More commonly, pregnant leach liquors (solutions
loaded with the value metal) are stripped of their values by operations
such as the cementation process step for copper or the solution extrac-
tion process step of the type used for several metals. Stripped leaching
solutions also may be ponded for recycling. In all cases, the ponded
liquors require control to prevent the inadvertent discharge of the liquid
waste to the surrounding environment.
The principal problems with leach liquors are identifiable as spills when
incurred under such circumstances as ruptures in cross-country pipelines,
washouts of dikes or dams by flood, or, in one case, overflow during a
labor strike. Elaborate surveillance, spill control, and containment
safety measures are necessary precautions.
Solution Extraction. Leach liquors may be stripped of their mineral
values in a solution extraction process step. These operations consist
of mixing the pregnant leach liquor with an organic liquid which preferen-
tially and sometimes quantitatively removes the value metal ion from the
leach liquor with simultaneous dissolution in the organic. The solutions
may be separated in settling tanks. The spent leach liquor is known as
the raffinate and may be discharged as described in the preceding section
on leaching. In a few cases, the raffinate may contain another value
metal from leaching, selectively rejected by the first organic solution
(e.g., vanadium from uranium solutions), and is further processed to col-
lect the second value. Quite often the raffinate contains only very
small amounts of residual values, but may contain a large burden of waste
materials. Thus, control of raffinates to prevent liquid waste emission
to the environment is essential.
The mixing of leach liquor and organic solution in the extraction circuit
is followed by remixing of the organic with a stripping solution. The
14
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value metal goes to the stripping solution preferentially; in effect it
is the reverse of the extraction circuit. The stripping solution may be
small in volume to achieve maximum concentration. Precipitation from the
stripping solution is accomplished either by adjustment of pH or by addi-
tion of other chemicals. The organic solutions are high priced and the
stripping solutions carry the value metal. Therefore, great care is
taken not to have losses in either. Nevertheless, the possibility of
spills exists and these must be considered in the total picture for
liquid waste emissions.
Tailings Ponds and Reservoirs. Tailings ponds are frequently used as one
of the storage reservoirs in plant water recirculation practice, but,
more importantly, they are used as the sink for the sedimentation of
solids emanating from the total operation. As described in preceding
sections, scrubber water, equipment cooling water, and water from the
various beneficiation process steps (e.g., flotation, leaching raffinate)
as well as excess mine water and possibly sanitary system water may pass
to the tailings pond. Particulate, colloidal, and soluble wastes might
therefore be present, and the control of such mixtures is essential. The
treatment of water for quality improvement prior to discharge is fre-
quently practiced. However, inadequate water treatment and wet season
overflow discharges may permit the wastes to be carried to area streams.
The tailings ponds associated with large flotation concentration opera-
tions are one of the outstanding characteristics of the mining industry.
They are invariably large [hectares to hundreds of hectares (acres to
hundreds of acres)]. Depending on climate and plant capacity, the tail-
ings pond may serve as a major water treating and conservation device or
as the major apparent source of water discharge. For example, in the
arid southwestern.states, all water is usually discharged to the tail-
ings pond, and because of long retention times which lead to a good
degree of water quality, the tailings pond then serves as a source of a
large fraction of process water.
In climates with a positive net annual accumulation of rainfall, dis-
charges from the tailings pond are necessary. The quality of the dis-
charge water varies with the individual operation. In some cases,
economical treatment is a problem because of the large volume involved.
Emission of Solid Wastes - Voluminous solid wastes are generated in the
metal-mining industry. The most recent published statistics on the quan-
tities of waste materials generated by metal-mining operations are indi-
cated in Table IV. This information is compiled annually by the Bureau
15
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TABLE IV. MATERIAL HANDLED AT SURFACE AND UNDERGROUND MINES, BY COMMODITY, IN 1972
(Thousand Short Tons)
01
Commodity
Aluminum
Copper
Cold
Iron Ore
Lead
Mercury
Silver
Titanium
Tungsten
Uranium
Zinc
Other(d>
Total metals
Surface
Crude Ore Waste
2,560
237,000
4,870
197,000
-
51
69
26,100
8
3,800
19
19.400
l) 491,000
(a) Data may not add to
(b) Includes underground
(c) W Withheld to avoid
9,230(b>
683,000
16,106
167,000
102
53
32
823
52
171,000
32,300
1,080,000
Underground
Total
11.800(b)
920,000
20,930
364,000
102
105
100
27,000
60
175,000
19
51,600
1,570,000
Crude Ore
w
34,700
1,700
11,600
9,560
30
588
-
•734
2,690
8,180
15.800
85,700
Waste
W
685
219
1,310
452
3
160
-
130
654
948
562
5,120
totals shown because of independent rounding.
; the Bureau of Mines is not at liberty to publish
disclosing individual company confidential data,
Total(a>
W
35,400
1,910
12,900
10,000
34
749
-
864
3,350
9,130
16.300
90,800
Crude Ore
2,560
271,000
6,560
209,000
9,560
82
657
26,100
741
6,450
8,210
35,200
576,000
All Mines
Waste
9,230
684,000
16,306
168,000
554
57
192
823
182
172,000
948
32,900
1,080,000
Total
11,800
955,000
22,930
377,000
10,100
138
849
27,000
923
178,000
9,150
68,000
1,660,000
separately.
included with "Surface".
(d) Antimony, beryllium, magnesium, manganese, molybdenum, nickel, platinum group metals, rare-earth metals, tin, and
vanadium.
-------
of Mines, and does not include in the waste column the wastes from con-
centrating operations, i.e., only mining wastes are reflected in the
table. The tailings from the crude ore, after extraction of the value
minerals, will constitute a waste quantity in addition to the wastes
given in the table.
The composition of the solid waste from the industry is dependent on the
characteristic rock types, as well as on other raw material additions.
In general, the solids are not toxic, but may be hazardous to health in
other respects, as is the case of asbestiform minerals. They may also
become a source for toxic emissions as they weather and otherwise alter
with time to give up undesirable chemicals.
Open-Pit fining. Literally, mountains of overburden material may be
removed in open-pit mining prior to achieving access to the ore body.
Stripping techniques and efficiencies have so greatly improved that up
to tens to hundreds of meters (hundreds of feet) of overburden may be
removed. The waste material is stored in heaps adjacent to the pits
for possible restoration to the pit at some later time.
Once the ore body is exposed, it may be exploited directly with all sub-
sequent blasting and loading, or as in numerous cases, it may require
selective mining to separate ore from waste rock and rich ore from lean
ore. Waste country rock can amount to very large tonnages. For example,
the estimate for the waste rock in the open-pit being developed by
Climax Molybdenum, Colorado, is 236 million metric tons (260 million
short tons). Since the ore reserve being opened is estimated at 168
million metric tons (185 million short tons), the waste-to-ore ratio is
1.4 to 1. The waste rock will, of course, be added to the waste heaps.
The problems with rock heaps range from unsightliness through dis-
ruptions of wildlife habitat, to being a source of toxic materials to
the air and water as the rocks weather and alter chemically with time.
Underground Mining. There is typically less waste rock associated with
underground mining than with open-pit mining for several reasons. First,
little or no overburden need be removed prior to development of shaft or
adit. Secondly, ores mined by underground methods are necessarily richer
to support the higher cost of underground mining. Further, massive exca-
vation of barren country rock is avoided wherever possible because of the
expense and because a limited passageway from one ore pocket to the next
is quite sufficient for ore access. Nevertheless, the quantities of
waste mine rock generated can be very large for some underground opera-
tions and these accumulate in waste rock storage heaps at some minimum
distance from the mine.
17
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Placer Mining. The solid waste rock emission for placer mining is prob-
ably less than for either open-pit or underground mining. However, large
quantities of relatively unconsolidated detrital rock are usually dis-
placed in placer mining. The spoil banks of disturbed rock may be
replaced fairly easily in some workings. In other cases, the spoil banks
remain as a disturbing blight on the landscape, marking in perpetuity the
path of the dredges. Apart from the unsightliness of these solid waste
heaps, the heaps may contribute to the ravages of a stream caused by
channelization, and, as heap material may be redistributed in floodtime,
the entire character of a water body may be altered by the loosened and
redistributed material.
Gangue Minerals--Tailings. The ore minerals in a deposit may constitute
a very small percentage of the ore body, or, as in the case of aluminum
ore (bauxite), may comprise almost the total amount mined. The worthless
portion of the mined ore is eliminated in numerous beneficiation process
steps, and is variously referred to as gangue, tails, tailings, waste,
and waste rock.
The first cut or separation of gangue from value minerals may occur in
the first screening or the first washing process step. Thereafter, many
of the process steps can result in a tail or a residue consisting princi-
pally of gangue, which is routed to solid waste disposal sites. Most
frequently, this site is the tailings pond. Very large quantities of
gangue or tailings may accumulate from the beneficiation steps. The
process steps usually contributing to solid waste emissions of this type
include the following:
Screening
Washing
Classifying
Gravity concentrating
Flotation concentrating
Magnetic concentrating
Electrostatic concentrating
Solid-liquid separation processes
(e.g.', filtering).
These are not the only process steps wherein the worthless material is
separated. Solid waste also is produced in the various leaching processes
In addition, tailings may contain a variety o.f noxious chemicals with the
potential of giving up these compounds to the environment.
18
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Leach Residues. Residues from the various leaching practices contribute
to the solid wastes associated with metal mining and beneficiation. Tank
or vat leaching leaves a washed residue which may be stored in dumps and
is capable of emitting compounds to the environment during storage. Heap
leaching may entail less washing after leaching due to the giant size of
the heap and other factors. Consequently, leached heaps may constitute
solid waste environmental problems not only due to their bulk but as well
to their residual acid, cyanide, and other possibly noxious chemical con-
stituent.
Miscellaneous Solid Wastes. Residues from thermal operations such as
retorting may consist of gangue and other process materials which may be
disposed of as solid waste. The material may be leached prior to dis-
card. Residues from mercury furnacing operations may be simply dumped.
Other solid waste disposal problems may be associated with such items as
spent resins from ion exchange separation processing steps, junk accumu-
lation in plant operation, and sanitation wastes.
Overview - The following listing briefly summarizes the unit process
operations and the emissions discussed in this section. The listing
is arranged to show the relationship of emissions to unit process.
Open-pit Mining
Equipment engine exhausts
Blasting emissions
Digging and transport dusts
Run-off water
Mine water
Overburden and waste mine rock
Dusting of waste heaps
Waste heap run-off
Underground Mining
Ventilation air—dust and possible mine gases
Mine water
Waste mine rock
Dusting
Run-off water
19
-------
Crushing
Dust
Screening
Dust
Grinding
Dust (if performed dry)
Flotation Concentration
Tailings Slurry
Water containing flotation reagents
Suspended solids (tailings)
Gravity Separations
Water containing conditioning chemicals
Suspended solids (tailings)
Heavy media residuals
Tailings Ponds
Dusting from dry portions
Water outfalls—suspended and dissolved solids
Tailings
Leaching
Acid, alkali, and/or solvent spills
Leach residues (tailings)
Run-off water from residues
Drying, calcining, roasting, and retorting
Gases containing particulates, dust, fume, vapors
or gaseous reaction products
Solid residue (in the case of retorting or roasting
of volatile metals).
20 .
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References
The following references are general references. Specific references for
the processes covered in the flowsheet are provided at the end of each
flowsheet.
(1) Wood, R. A.; Hallowell, J. B.; and Cherry, R. H. Jr.; Demonstra-
tion Opportunities in the U.S. Metals-Mining Industry, Battelle-
Columbus Laboratories to Environmental Protection Agency, Control
Systems Laboratory, Contract 63-02-1323, Task No. 15, December 31,
1974.
(2) Hallowell, J. B., et al., Hater Pollution Control in the Primary
Nonferrous Metals Industry, Vol. II, Aluminum, Mercury, Gold,
Silver, Molybdenum, and Tungsten, Battelle-Columbus Laboratories
to Office of Research and Monitoring, U.S. Environmental Protec-
tion Agency, EPA R2-73-247b, September, 1973.
(3) Private communication with members of the Battelle-Columbus staff
and with metal industry representatives on energy usage in U.S.
metal mining and beneficiation.
(4) Calspan Corporation Development Document for Effluent Limitations
Guidelines and Standards of Performance to U.S. EPA Office of
Water and Hazardous Materials, Effluent Guideline Division,
Contract No. 63-01-2682, April, 1975.
(5) Staff, Bureau of Mines, Mineral Facts and Problems, 19.70, Bureau
of Mines Bulletin 650, Bureau of Mines, U.S. Department of the
Interior.
(6) Staff, Bureau of Mines, Mineral Facts and Problems, 1965, Bureau
of Mines, U.S. Department of the Interior.
INDUSTRY ANALYSIS
Flowsheets covering process descriptions of the following segments of the
metal-mining and ore-dressing industries are covered in this report.
Aluminum
Antimony
Beryllium
Copper
21
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Gold
Iron
Lead and zinc
Mercury
Molybdenum
Nickel
Platinum Group Metals
Rare Earth Metals
Silver
Titanium
Tungsten
Uranium
Vanadium.
As indicated earlier, six of the 23 industry segments are not covered
by individual flowsheets because either the U.S. is completely dependent
on foreign sources for the particular metal or metallic ore or it is a
by-product and is covered in the flowsheet for the principal metallic
ore. The six segments of the industry which fall into these two cate-
gories are as follow:
Chromium - The U.S. is completely dependent on foreign
sources for chromite, the only commercial source of
chromium. No chromite has been mined fn the United
States since 1961.
Columbium (Niobium)-Tantalum - There is virtually
no U.S. production of ores of these metals. Very
small amounts are produced from a single California
mine as a by-product with noble and rare earth metals.
Manganese - The U.S. is almost completely dependent
on imports for its manganese; 98 percent is imported,
2 percent is obtained from secondary manganese and
from manganiferous iron ores charged to the blast
furnace.
Thorium - U.S. thorium production (about 150 metric
tons per year) is almost entirely as a by-product
from the rare-earth containing mineral monazite,
itself a by-product of U.S. east coast titanium and
Colorado molybdenum minerals production. Small
amounts are also obtained as a by-product from
Alaskan uranium ore. Thorium-by-product production
is covered in the flowsheets covering these principal
ore values.
22
-------
Tin - The U.S. is wholly dependent on foreign sources
for tin (imports amounted to 55,000 metric tons in
1973). About 100 metric tons are produced each year
as a by-product of primary molybdenum recovery in
Colorado.
Zirconium - Zircon (ZrSi04), the principal mineral
source of zirconium is recovered as a by-product in
the mining of titanium and monazite minerals in beach
sand deposits. This is covered in the titanium
segment. Waste characteristics and water uses accom-
panying mining and mi 11 Inn to obtain zircon concentrate
are identical to those for titanium minerals.
Raw materials (ores) and products for these metal segments which are not
covered individually in flowsheets are shown in Appendix A with the names
of companies producing the metal or associated product.
The flowsheets of metals mined and beneficiated in the U.S. are arranged
alphabetically as in the listing above. The flowsheets contain process
descriptions of the various industry segments. Subdivisions in processing
steps have been made where emissions to the environment are significant.
Type of emissions—gaseous, liquid waste, and solid waste—are indicated
by appropriate flags Csee flowsheets) placed on the isolated processing
steps. Input materials and products are shown enclosed in circles, pro-
cessing steps are shown in enclosed boxes. Information provided in the
flowsheets includes a description of the function of the processing step,
specific details on materials, input and output, operating parameters,
energy expenditure of utilities per ton of ore processed, and details of
emissions and waste streams from each processing unit. The EPA Source
Classification is given if it exists, and references from which details of
operation were obtained are provided at the end of each process flowsheet.
23
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Aluminum
While the United States is a large consumer of the world
production of aluminum, a very small amount of the ore
for aluminum production, bauxite, is mined domestically.
Over 90 percent of our domestic aluminum production
is based on bauxite imported from foreign mining and
beneficiating operations. The U.S. bauxite production is
about 2 million short tons (2.07 million tons in 1973
which was about 7 percent of our bauxite requirements)
whereas the world production of bauxite is approximately 73
million short tons.
The silica content and the form in which it is present in a
bauxite ore body are important factors in the yield of a
bauxite ore. On a molar basis, two parts of silica tie up
one part of alumina in the mineral kaolinite Al203.2Si02.2H20.
The silica content results in the consumption of caustic
solution in the formation of insoluble sodium aluminum
silicate in refining operations. (The use of high-silica
bauxites involves excess reagent losses or the use of a
two-step, "combination" process to recover the losses in the
initial processing.) In some operations in the U.S., kaolin
is a coproduct of bauxite production and the bauxite itself
may be capable of beneficiation only to a nonmetallurgical
grade (for example, for ultimate use in refractories or
abrasives rather than for metal production). Metallurgical
grade bauxite ore is produced in the U.S., however, notably from
the Arkansas deposits.
24
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Aluminum
tv>
en
Crushing
Washing, &
Screening
To Bayer Refinery
To Manufacturing
(Refractories, Etc.]
y Atmospheric Emissions
P Liquid Waste
~O Solid Waste
-------
ALUMINUM - HIGH GRADE BAUXITE ORE PROCESS NO. 1
Open-Pit Mining of Bauxite Ore
1. Function - Extraction of bauxite, a hydrated aluminum oxide
which is the predominant ore of aluminum, from an ore body
lying near the surface. In the course of extraction, over-
lying waste rock, or overburden, is removed up to thicknesses
of 50 meters.
2. Input Materials - Ammonium nitrate—fuel oil slurry
explosives: 0.1 kg/metric ton (1 Ib/short ton) of
material or 0.4 kg/metric tons (0.3 Ib/short tons) of bauxite
ore.
3. Operating Parameters -
Temperature: Ambient
Pressure: Atmosphere
4. Utilities -
Electrical Energy, shovel loading, drilling, etc: 1.91gx
IQo joules/metric ton (53 kWhe/metric ton or 0.51 x 10 Btu/
short ton) of bauxite
Diesel fuel, truck transportation: 0.68 liters/metric ton
(0.163 gal/short ton) of bauxite
5. Waste Streams -
Dust and vapor emissions from blasting, digging, and loading
operations
Water emissions from spraying to control dust, mine drainage,
sometimes acidic
Storage of overburden in heaps adjacent to pits
6. EPA Source Classification Code - None
7. References -
(1) Center for Industrial Development, Department of Economic
and Social Affairs, United Nations, Studies in Economics
of Industry, "2. Preinvestment Data for the Aluminum
Industry, United Nations".
26
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(2) Chapman, Peter F., "The Energy Cost of Producing Copper and
Aluminum from Primary Sources", Open University Energy
Research Group Report, No. ERG 001, August 1973, (revised
December 1973).
(3) Farin, Philip, Associate Editor, "Aluminum, Profile of the
Industry", Metals Week, McGraw-Hill, Inc., 1969.
(4) Bulletin 650, "Mineral Facts and Problems, Aluminum", 1970,
Bureau of Mines, U.S. Department of the Interior, pp 437-462.
27
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ALUMINUM - HIGH GRADE BAUXITE ORE PROCESS NO. 2
Crushing, Washing, and Screening
1. Function - Bauxite is crushed to a uniform size. The size
produced varies with the hardness of the bauxite ore. The
crushed ore is-passed over washing screens to remove clay
and silica.
2. Input Materials - Bauxite ore and water
3. Operating Parameters -
Temperature: Ambient
Pressure: Atmospheric
4. Utilities -
o
Electric energy, crushing, and screening: 2.12 x 10 joules/
metric ton (59 kWhe/metric ton or 0.56 x 10° Btu/short ton)
bauxite o
Electric energy, pumping: 1.08 x 10 joules/metric ton
(30 kWhe/metric ton or 0.29 x 10& Btti/snort ton) bauxite
5. Waste Streams -
Dust emissions from crushing and conveyors
Water emissions from washing
Clay and silica waste from washing and screening operation
6. ' EPA Source Classification Code - None
7. References -
(1) Center for Industrial Development, Department of Economic
and Social Affairs, United Nations, Studies in Economics
of Industry, "2. Preinvestment Data for the Aluminum
Industry, United Nations".
(2) Chapman, Peter F., "The Energy Cost of Producing Copper and
Aluminum from Primary Sources", Open University Energy
Research Group Report, No. ERG 001, August 1973, (revised
December 1973).
28
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(3) Farin, Philip, Associate Editor, "Aluminum, Profile of the
Industry", Metals Week, McGraw-Hill, Inc., 1969.
(4) Bulletin 650, "Mineral Facts and Problems, Aluminum", 1970,
Bureau of Mines, U.S. Department of the Interior, pp 437-462.
29
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ALUMINUM - HIGH GRADE BAUXITE ORE PROCESS NO. 3
Drying
1. Function - Removal of excess moisture (5 to 25 percent) from
crude bauxite to reduce weight and shipping charges. (In
some instances, drying is unnecessary.)
2. Input Materials - Crude bauxite
3. Operating Parameters -
Temperatures: up to 400 C (752 F). (Temperatures in the upper range
are sometimes used to destroy organic materials and improve
the digestion rate.)
' Pressure: Atmospheric
4. Utilities -
Q
Natural gas ( or heavy oil) for drying: (0.14-3.4) x 10 ft
joules/metric ton [3.8-94 kWhe/metric ton (0.036-0.90) x 10
Btu/short ton] bauxite
5. Waste Streams -
Dust emissions, combustion products
6. EPA Source Classification Code - None
7. References -
(1) Center for Industrial Development, Department of Economic
and Social Affairs, United Nations, Studies in Economics
of Industry, "2. Preinvestment Data for the Aluminum
Industry, United Nations".
(2) Bielfelt, K; Kampf, F.; and Winkhaus, G.; "Heat Consump-
tion in the Production of Aluminum", Paper No. A75-58,
Preprint of paper given at the 104th AIME Annual Meeting,
Americana Hotel, New York, N.Y., February 18, 1975.
(3) Farin, Philip, Associate Editor, "Aluminum, Profile of the
Industry", Metals Week, McGraw-Hill, Inc., 1969.
(4) Bulletin 650, "Mineral Facts and Problems, Aluminum", 1970,
Bureau of Mines, U.S. Department of the Interior, pp 437-462.
30
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ALUMINUM - LOW GRADE BAUXITE ORE PROCESS NO. 1
Open-Pit Mining of Low Grade Bauxite Ore
1. Function - Extraction of nonmetallurgical grades of bauxite
ore body near the surface for further processing into cal-
cined bauxite for use in the abrasives and refractory
industries.
2. Input Materials - Ammonium nitrate—fuel oil slurry
explosives: 0.1 kg/metric ton (.2 Ib/short tons) or 0.4
kg/metric ton (0.8 Ib/short tons) of bauxite ore.
3. Operating Parameters -
Temperature: Ambient
Pressure: Atmospheric
4. Utilities -
Electrical energy, shovel loading, drilling, etc.:
1.91rx 108 joules/metric ton (53 kWhe/metric ton or 0.51
x 10° Btu/short ton) bauxite.
g
Diesel fuel, truck transportation: 1.62 x 10 joules/
metric ton (45 kWhe/metric ton or 0.43 x 10° Btu/short ton)
bauxite
5. Waste Streams - .
Dust and vapor emissions from blasting, digging, and loading
operations
Water emissions from spraying to control dust, mine drainage,
sometimes acidic
Storage of overburden in heaps adjacent to pits
6. EPA Source Classification Code - None
7. References -
(1) Center for Industrial Development, Department of Economic
and Social Affairs, United Nations, Studies in Economics
of Industry, "2. Preinvestment Data for the Aluminum
Industry, United Nations".
31
-------
(2) Kirk-Othmer Chemical Encyclopedia, Aluminum Compouds,
Vol 2, 1963 Edition, pp 56-57.
(3) Farin, Philip, Associate Editor, "Aluminum, Profile of the
Industry", Metals Week, McGraw-Hill, Inc., 1969.
(4) Bulletin 650, "Mineral Facts and Problems, Aluminum", 1970,
Bureau of Mines, U.S. Department of the Interior, pp 437-462.
32
-------
ALUMINUM - LOW GRADE BAUXITE ORE PROCESS NO. 2
Crushing, Washing, and Screening
1. Function - Bauxite is crushed to a uniform size. The size
produced varies with the hardness of the bauxite ore. The
crushed ore is passed over washing screens to remove clay
and silica.
2. Input Materials - Bauxite ore and water
3. Operating Parameters -
Temperature: Ambient
Pressure: Atmospheric
4. Utilities -
Electric energy, crushing, and screening: 2.12 x 108
joules/metric ton (59 kWhe/metric ton or 0.56 x 10° Btu/short
ton) bauxite
o
Electric energy, pumping: 1.08 x 10 joules/metric ton
(30 kWhe/metric ton or 300,000 Btu/short ton) bauxite
5. Waste Streams -
Dust emissions from crushing and conveyors
Water emissions from washing
Clay and silica waste from washing and screening operation
6. EPA Source Classification Code - None
7. References -
(1) Center for Industrial Development, Department of Economic
and Social Affairs, United Nations, Studies in Economics
of Industry, "2. Preinvestment Data for the Aluminum
Industry, United Nations".
(2} Kirk-Othmer Chemical Encyclopedia, Aluminum Compounds,
Vol 2, 1963 Edition, pp 56-57
(3) Farin, Philip, Associate Editor, "Aluminum, Profile of the
Industry", Metals Week, McGraw-Hill, Inc., 1969.
33
-------
(4) Bulletin 650, "Mineral Facts and Problems, Aluminum", 1970,
Bureau of Mines, U.S. Department of the Interior, pp 437-462.
34
-------
ALUMINUM - LOW GRADE BAUXITE ORE PROCESS NO. 3
Calcining
!• Function - The chemically combined water in the nonmetallurgical
grades of bauxite must be removed prior to processing it into
brown fused alumina in an electric arc furnace. Normally, a
prior drying step is unnecessary unless the calcining plant is
at a considerable distance from the crushing, washing, and
screening plant.
2. Input Materials - Washed and screened low grade bauxite
3. Operating Parameters -
Temperature: 930-1600 C (1700-2900 F) for 1-1/2 hr, depending
on use
Pressure: Atmospheric
4. Utilities -
o
Natural gas or heavy oil: (24.6-41.6) x 10 joules/
metric ton [(683-1160) k\lhe/metric ton or (6.5-11) x
10° Btu/short ton] of fesd
5. Waste Streams -
Dust emissions, combustion products
6. EPA Source Classification Code - None
7. References -
(1) Center for Industrial Development, Department of Economic
and Social Affairs, United Nations, Studies in Economics
of Industry, "2. Preinvestment Data for the Aluminum
Industry, United Nations".
(2) Kirk-Othmer Chemical Encyclopedia, Aluminum Compounds,
Vol 2, 1963 Edition, pp 56-57.
(3) Farin, Philip, Associate Editor, "Aluminum, Profile of the
Industry", Metals Week, McGraw-Hill, Inc., 1969.
(4) Bulletin 650, "Mineral Facts and Problems, Aluminum", 1970,
Bureau of Mines, U.S. Department of the Interior, pp 437-462.
35
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Antimony
Only about 2 percent of our domestic antimony requirements are
generated from U.S. mining operations and the bulk of this is
produced as by-product antimony from complex Idaho ores (see
Lead Segment). Limited information is available on a new
Montana mine under development for the production of antimony
(apparently principally for antimony) and the same is the case
for small "one-man" prospecting and mining operations that
develop intermittently in the western and northwestern states
(e.g., Nevada small tonnage operation).
The products from the antimony mining and beneficiating
segments of the industry are appropriately named grades of ore
concentrate, for example, high-grade or low-grade concentrate.
Refinery products resulting from liquation or volatilization
operations are commonly named "Crude", "Crudum", or "Needle"
(melted and solidified Sb2'Ss) and "Stibnox" (volatilized
and condensed Sb20s) from the respective operations. The
refining operations are currently seldom if ever used as a
part of the beneficiating process.
36
-------
Antimony
Water
U>
/ High \
I Grade V*J
Underground
Mining
Y Atmospheric Emissions
y Liquid Waste
Solid Waste
i
Crushing,
Grinding,
Classifying
Limited
Crushing,
Classifying
Water
J_
Gravity.
Flotation
Concentration
Medium-
Grade Ore
Concentrate
To Refinery
High-
Grade Ore
Concentrate
Volatilization
(High Heat
Input)
-------
ANTIMONY - MEDIUM GRADE ORE PROCESS NO. 1
Underground Mining of Medium Grade Antimony Ore
1. Function - Extraction of stibnite (SbpSJ or oxidized stib-
nite ores from small discontinuous deposits which are
entered through a short adit or shallow shaft and removed
by sill cutting in the plane of the vein or by overhead
stoping.
2. Input Materials - Explosives: nitroglycerine derivatives
3. Operating Parameters -
Temperature: Ambient
Pressure: Atmospheric
4. Utilities -
Electric energy, drilling, hoisting, pumping, etc.: 1.80
x 10 joules/metric ton (50 kWhe/metric ton or 0.48 x 10
Btu/short ton) of ore.
5. Waste Streams -
Air emissions from shaft or adit
Water emissions from mine pumps
Storage of waste rock in heaps adjacent to shaft or adit
6. EPA Source Classification Code - None
7. References -
(1) Paone, James, Chapter on Antimony; Mineral Facts and
Problems 1970, Bureau of Mines Bulletin 650, Bureau
of Mines, U.S. Department of the Interior, Washington,
D.C., pp 463-478.
(2) Wyche, Charlie, Preprint of Chapter on Antimony, Vol 1
of the 1970 Minerals Yearbook, Bureau of Mines, U.S.
Department of the Interior, Washington, D.C., 9 p.
(3) Private communications with members of the BCL staff
who have consulted producers on energy requirements.
38
-------
ANTIMONY - MEDIUM GRADE ORE PROCESS NO. 2
Crushing, Grinding, and Classifying
1. Function - Medium grade antimony ores are frequently crushed,
ground, and classified to a sufficient degree of fineness to
affect a separation of particles of the mineral stibnite
(56253) from particles of gangue in subsequent beneficiation
processes. In some cases, the ore, after being hand-cobbed,
is smelted directly.
2. Input Materials - Broken medium grade antimony ore delivered
to the shaft house crusher bins in mine skips.
3. Operating Parameters -
Temperature: Ambient
Pressure: Atmospheric
4. Utilities -
o
Electric energy: 7.92 x lOgjoules/metric ton (220
kWhe/metric ton or 2.1 x 10 Btu/short ton) of ore.
5. Haste Streams -
Dust emissions from crushers and conveyors
Water emissions from classifiers
Solid waste from gangue discard
*
6. EPA Source Classification Code - None
7. References -
(1) Paone, James, Chapter on Antimony; Mineral Facts and
Problems 1970, Bureau of Mines Bulletin 650, Bureau
of Mines, U.S. Department of the Interior, Washington,
D.C., pp 463-478.
(2) Wyche, Charlie, Preprint of Chapter on Antimony, Vol 1
of the 1970 Minerals Yearbook, Bureau of Mines, U.S.
Department of the Interior, Washington, D.C., 9 p.
(3) Private communications with members of the BCL staff
who have consulted producers on energy requirements.
39
-------
ANTIMONY - MEDIUM GRADE ORE PROCESS NO. 3
Gravity Concentration, Flotation
1. Function - Medium and low grade antimony ores are concentrated
by ore-dressing methods in only some cases; oxide ores may be
concentrated by jigging; stibnite (SbpSJ ores by flotation
(which separates out associated arsenic minerals). Concentra-
tion by such means, particularly gravity concentration, has
the disadvantage of high slime loss; hence, medium grade ores
are often smelted directly, and low grade ores volitilized to
produce antimony oxide, removing arsenic in the process because
its oxide is more volitile.
2. Input Materials - Crushed and ground antimony ore
3. Operating Parameters -
Temperature: Ambient
Pressure: Atmospheric
4. Utilities -
Q
Jigs, flotation machines, pumps, etc: 3.78 x 10 joules/
metric ton (77 kWhe/metric ton or 0.73 Btu/short ton) of ore.
5. Waste Streams -
Water emission from jigs and flotation processing
Solid waste from tailings discharged from jigs and flotation
machines
6. EPA Source Classification Code - None
7. References -
(1) Paone, James, Chapter on Antimony; Mineral Facts and
Problems 1970, Bureau of Mines Bulletin 650, Bureau
of Mines, U.S. Department of the Interior, Washington,
D.C., pp 463-478.
(2) Wyche, Charlie, Preprint of Chapter on Antimony, Vol 1
of the 1970 Minerals Yearbook, Bureau of Mines, U.S.
Department of the Interior, Washington, D.C., 9 p.
40
-------
(3) Private communications with members of the BCL staff
who have consulted producers on energy requirements.
(4) Kellog, H. H., "Energy Consumption in Flotation
Beneficiation", (unpublished) Columbia University,
New York, N.Y., July 1973.
41
-------
ANTIMONY - HIGH GRADE ORE PROCESS NO. 1
Underground Mining of High Grade Antimony Ore
1. Function - Extraction of stibnite (SbS) or oxidized stibnite
ores from small discontinuous deposits which are entered
through a short adit or shallow shaft and removed by sill
cutting in the plane of the vein or by overhead stoping.
2. Input Materials - Explosives: nitroglycerine derivatives
3. Operating Parameters -
Temperature: Ambient
Pressure: Atmospheric
4. Utilities -
Electric energy, drilling, hoisting, pumping, etc: 1.80 x
108 joules/metric ton (50 kWhe/metric ton or 0.48 x 10
Btu/short ton) of ore.
5. Waste Streams -
f\ir emissions fror^ shaft cr adit
Water emissions from mine pumps
Storage of waste rock in heaps adjacent to shaft or adit
6. EPA Source Classification Code - None
7. References -
(1) Paone, James, Chapter on Antimony; Mineral Facts and
Problems 1970, Bureau of Mines Bulletin 650, Bureau
of Mines, U.S. Department of the Interior, Washington,
D.C., pp 463-478.
(2) Wyche, Charlie, Preprint of Chapter on Antimony, Vol 1
of the 1970 Minerals Yearbook, Bureau of Mines, U.S.
Department of the Interior, Washington, D.C., 9 p.
(3) Private communications with members of the BCL staff
who have consulted producers on energy requirements.
42
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ANTIMONY - HIGH GRADE ORE PROCESS NO. 4
Limited Crushing and Classifying
1. Function - Owing to the extreme friability of stibnite
(Sb^S-J, concentration by wet means' of ground high grade
(45-60 percent antimony) ores entails prohibitively high
slime losses. Accordingly, high grade antimony ores
receive only a limited amount of crushing. Concentration
to increase the stibnite (Sb^S,; 71.5 percent antimony)
in high grade ores is usually by liquation, and sometimes
by precipitation by iron from molten antimony sulfide.
2. Input Materials - Crushed ore
3. Operating Parameters -
Temperature: Ambient
Pressure: Atmospheric
4. Utilities -
Q
Crushers, conveyors: 0.79 xg10 joules/metric ton (22
kWhe/metn'c ton or 0.21 x 10 Btu/short ton) of ore.
5. Waste Streams -
Dust emissions from crushers and conveyors
Solid waste from hand-cobbing procedures
6. EPA Source Classification Code - None
7. References -
(1) Paone, James, Chapter on Antimony; Mineral Facts and
Problems 1970, Bureau of Mines Bulletin 650, Bureau
of Mines, U.S. Department of the Interior, Washington,
D.C., pp 463-478.
(2) Wyche, Charlie, Preprint of Chapter on Antimony, Vol 1
of the 1970 Minerals Yearbook, Bureau of Mines, U.S.
Department of the Interior, Washington, D.C., 9 p.
(3) Private communications with members of the BCL staff
who have consulted producers on energy requirements.
43
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Beryllium
The world production of beryllium ore (of more than one type but
equivalent to the mineral beryl containing 11 percent beryllium
oxide, BeO) was about 5000 tons in each of the last several years.
While more than this amount is being used by the United States on
an annual basis, considerable amounts used are from stockpiles.
The U.S. production of beryllium ore (from beryl containing ore
bodies in Colorado and South Dakota and from the Utah bertrandite
deposit) represents less than half of the total world production.
The exact U.S. production figures for beryllium ores are withheld
to avoid disclosing company confidential data.
Beryl is frequently found in rather large crystals in pegmatite
deposits which permits the recovery of beryl in an unadulterated
crystal form. Hand sorted (also know as hand cobbed) concentrates
of beryl crystals are the common product from pegmatite mining
operations. The bertrandite deposit in Utah contains considerable
gangue material in- an intimate mixture with the beryllium mineral.
An acid-leaching process is therefore used to extract the value
portion of the ore and this process results in a leach slurry.
The beryllium content comes out of the ore in the acid-water-
soluble compound, beryllium sulfate, BeSO*, and is recovered as
the filtrate from the leach slurry. Thus, the direct products of
the industry are (a) beryl concentrate (in the form of crystals),
and (b) beryllium sulfate in acidic solution.
44
-------
Beryllium
en
I Atmospheric Emissions
? Liquid Waste
—D
Solid Waste
-------
BERYLLIUM - PEGMATITE ORE PROCESS NO. 1
\
Open-Pit Mining
1. Function - Simple open-pit mining methods are used to excavate
beryl-containing granite pegmatites. In the U.S., these
pegmatite deposits are usually mined primarily for feldspar,
mica, quartz crystals, lithium-bearing minerals, and gem
stones. Beryl, a crystalline beryllium-aluminum-silicate
(3BeO-Al203'6Si02), is present in very low concentrations in
these pegmatite deposits; 100 tons of rock yields about 1
ton of beryl.
2. Input Materials - Ammonium nitrate-fuel oil slurry explosives;
1 kg/metric ton of ore. Forty and 60 percent dynamite is also
used.
3. Operating Parameters -
Temperature: Ambient
Pressure: Atmospheric
4. Utilities -
Explosives, energy equivalent 2.91 x 108 joules/metric ton
(80.9 kWhe/metric ton or 0.77 x 106 Btu/short ton) of rock.
Diesel fuel, hauling, etc: 11.9 liters/metric ton (2.84 gal/
short ton) of rock.
5. Haste Streams -
Localized particulate and vapor emissions from drilling, blasting,
and rock handling operations.
Water run-off from mining operations
Waste rock stockpiles
6. EPA Source Classification Code - None
46
-------
7. References
(1) Chin, E., Preprint of Chapter on Beryllium for the 1973
Minerals Yearbook, Bureau of Mines, U. S. Department of
the Interior, Washington, D.C., 5 p.
(2) Heindl, R. A., Chapter on Beryllium, Mineral Facts and
Problems, 1970, Bureau of Mines Bulletin 650, Bureau of
Mines, U. S. Department of the Interior, Washington, D.C.,
pp 489-501.
(3) Private communication with members of the BCL staff who
have consulted producers for estimates on utilities energy
requirements.
47
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BERYLLIUM - PEGMATITE ORES PROCESS NO. 2
Crushing and Hand-Cobbing
1. Function - Beryl-containing ore from pegmatites is crushed and
hand-sorted, sometimes on belts to reclaim beryl and other
mineral values.
2. Input Materials - Broken, pegmatite rock
3. Operating Parameters -
Temperature: Ambient
Pressure: Atmospheric
4. Utilities -
Electric energy: 0.83 x 10° joules/metric ton (23 kWhe/metric
ton or 0.22 Btu/short ton of pegmatite rock.
5. Waste Streams -
Particulate emissions from crushing and handling
Waste rock remaining after hand-cobbing is hauled to dumps
6. EPA Source Classification Code - None
7. References -
(1) Chin, E., Preprint of Chapter of Beryllium for the 1973
Minerals Yearbook, Bureau of Mines, U.S. Department of
the Interior, Washington, D.C., 5 p.
(2) Heindl, R. A. Chapter on Beryllium, Mineral Facts and
Problems, 1970, Bureau of Mines Bulletin 650, Bureau of
Mines, U.S. Department of the Interior, Washington, D.C.,
pp 489-501.
(3) Private communication with members of the BCL staff who
have consulted producers for estimates on utilities
energy requirements.
48
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BERYLLIUM - BERTRANDITE ORE PROCESS NO. 1
Open-Pit Mining of Bertrandite Ore
1. Function - Extraction of beryl-containing bertrandite
hLO)ore from the largest domestic source of beryllium, the Spor
Mountain bertrandite mine near Delta, Utah. In this location,
bertrandite occurs erratically in altered tuff which lies close
to the surface and thus can be mined by open-cut methods.
2. Input Materials - Ammonium nitrate fuel oil slurry explosives
3. Operating Parameters -
Temperature: Ambient
Perssure: Atmospheric
4. Utilities -
Diesel-Electric Generators; Mining Operations: 118 x 10^ joules/
metric ton (3270 kWhe/metric ton or 31.1 x 106 Btu/short ton) of EeO,
5. Haste Streams -
Mo mining dust; the ore is set (16-22 percent moisture)
Water emissions from mining
Considerable amounts of gangue, most of which is separated in the
leaching step
6. 'EPA Source Classification Code - None
7. References -
(1) Chin, E., Preprint of Chapter on Beryllium for the 1973
Minerals Yearbook, Bureau of Mines, U.S. Department of
the Interior, Washington, D.C.., 5 p.
(2) Heindl, R. A., Chapter on Beryllium, Mineral Facts and
Problems, 1970, Bureau of Mines Bulletin 650, Bureau of
Mines, U.S. Department of the Interior, Washington, D.C.,
pp 489-501.
49
-------
(3) Private communication with members of the BCL staff who
have consulted producers for estimates on utilities
energy requirements.
50
-------
BERYLLIUM - BERTRANDITE ORE PROCESS NO. 3
Crushing, Grinding, and Screening
1. Function - Bertrandite(4BeO-2SiOo-H20) ores at the Spor
Mountain mine in Utah contain only an average of 0.65
percent beryllium (ranges from 0.5-1.5 percent). To
free the bertrandite minerals from associated gangue, the
ore is wet crushed, wet ground, and wet screened to a
thixotropic slurry in preparation for a leaching step.
2. Input Materials - Open-pit mined ore from the Spor Mountain
deposit and water.
3. Operating Parameters -
Temperature: Ambient
Pressure: Atmospheric
4. Utilities - (Includes pumping energy for leach solutions)
Diesel-Electric Power; 13.6 X 108 joules/metric ton (378 kWhe/
metric ton or 3.6 x 106 Btu/short ton) of ore.
5. Haste Streams -
No gaseous emissions: Wet crushing, grinding, and screening
No water emissions per se, since ore slurry goes on to the
leaching operation. Spills may occur.
The generation of waste rock occurs in the next step, leaching.
6. EPA Source Classification Code - None
7. References -
(1) Chin, E., Preprint of Chapter on Beryllium for the 1973
Minerals Yearbook, Bureau of Mines, U. S. Department of
the Interior, Washington, D.C., 5 p.
(2) Heindl, R. A., Chapter on Beryllium, Mineral Facts and
Problems, 1970, Bureau of Mines Bulletin 650, Bureau of
Mines, U. S. Department of the Interior, Washington, D.C.,
pp 489-501.
51
-------
(3) Private communication with members of the BCL staff who
have consulted producers for estimates on utilities energy
requirements.
52
-------
BERYLLIUM - BERTRANDITE ORE PROCESS NO. 4
Acid Solution Leaching
1. Function - the bertrandite (4BeO'2Si02'H2Q) ore slurry from
the wet grinding and screening operation is leached in 10
percent sulfuric acid solution to put the beryllium in
solution thus separating it from the insoluble gangue.
After leaching, solids are separated and washed by counter-
current displacement in a series of thickeners.
2. Input Materials - A slurry of wet ground bertrandite ore,
concentrated sulfuric acid, water.
3.. Operating Parameters
Temperature: Ambient
Pressure: Atmospheric
4. Utilities - (Includes energy required for crushing and grinding
besides that of leach pumping).
Diesel-Electric Power; 13.6 x 108 joules/metric ton (378 kWhe/
metric ton or 3.6 x 10° Btu/short ton) of ore.
5. Waste Streams -
Acid residue of slurries from leaching obtained from the
thickeners are combined with a sufficient amount of alkaline
solution to achieve a pH of 8 to 10 in the slurry of solids
discharged to waste storage lagoons.
6. EPA Source Classification Code - None
7. References -
(1) Chin, E., Preprint of Chapter on Beryllium for the 1973
Minerals Yearbook, Bureau of Mines, U. S. Department of
the Interior, Washington, D.C., 5 p.
53
-------
(2) Heindl, R. A., Chapter on Beryllium. Mineral Facts and
Problems, 1970, Bureau of Mines Bulletin 650, Bureau of
Mines, U. S. Department of the Interior, Washington, D.C.,
pp 489-501.
(3) Private communication with members of the BCL staff who
have consulted producers for estimates on utilities energy
requirements.
54
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BERYLLIUM - BERTRAMDITE ORE PROCESS NO. 5
'Solvent Extraction
1. Function - Beryllium, having been put into solution in dilute
10 percent sulfuric acid as an impure beryllium sulfate, is
selectively extracted using an organic chelating agent, di-2-
ethylhexyl phosphoric acid in a kerosene diluent. The extracted
beryllium in the organic solvent is separated from the spent
leach liquor (raffinate) in settling tanks, after which, in
subsequent steps, the organic solution containing the chelated
beryllium ions free of impurities is remixed with an alkaline
stripping solution to produce a solution containing an alkaline
berylate compound. The stripped organic phase is recycled.
Beryllium hydroxide is precipitated from the alkaline berylate
solution by boiling, and is separated from the filtrate by cen-
trifuging and filtering; the alkaline filtrate is recycled.
2. Input Materials - Impure beryllium sulfate in acid solution;
kerosene containing an organic chelating agent; alkaline
stripping solution
3. Operating Parameters -
Temperature: Extraction and stripping - Ambient
Precipitation of BeOH from stripping solution;
boiling
Pressure: Atmospheric
4. Utilities -
Pumping, diesel-electric power: 16.7 x ID8 joules/metric ton (464
kWhe/metric ton or 4.42 x 10^ Btu/short ton) of bertrandite ore.
5. Waste Streams -
Vapor escape from boiling alkaline berylate solution
No toxicological hazards
Spent leach liquor (raffinate)
Spills of organic solution in the extraction circuit
Spills of alkaline stripping solutions
55
-------
6. EPA Source Classification Code - None exists
7. References -
(1) Chin, E., Preprint of Chapter of Beryllium for the 1973
Minerals Yearbook, Bureau of Mines, U.S. Department of
the Interior, Washington, D.C., 5 p.
(2) Heindl, R. A., Chapter on Beryllium, Mineral Facts and
Problems, 1970, Bureau of Mines Bulletin 650, Bureau of
Mines, U.S. Department of the Interior, Washington, D.C.,
pp 439-501.
(3) Private communication with members of the BCL staff who
have consulted producers for estimates on utilities
energy requirements.
56
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Copper
Next to aluminum, copper is the leading nonferrous metal consumed
in the United States. We are practically self-sufficient in
providing our copper requirements from our mines and treatment
facilities (95 per cent). A vast network of mines and treatment
facilities distributed over several states produces about 2.3
million tons of copper annually. About 90 percent of our total
primary copper production is provided by 25 leading U.S. mines.
The most important copper-ore type in the United States is the
so-called "porphyry" copper deposits. These are extensive
masses of rock throughout which crystals of various copper
minerals are more or less uniformly disseminated, and which,
although low grade, may profitably be mined on a massive
nonselective scale. The porphyry copper deposits account
for the major portion of copper production. Porphyry
ores are usually mined by open-pit methods.
Economically important concentrations of copper minerals are
frequently found in association with minerals of other metals.
The most frequent associations are copper with lead or zinc,
copper with gold and silver, copper with molybdenum, and copper
with any combination of these metals. In addition, iron in
the form of pyrite is also a common associate. Other metal!ics
such as nickel, bismuth, antimony, etc. in usually small
quantities, also are found with copper minerals.
Due to the great variety of mineral assemblages found in copper
deposits, including minerals of other metals and nonmetals, it is
convenient to classify copper ores according to their predominant
mineral characteristics and economic grade.
(a) High-grade sulfide ores. These are generally obtained
from underground operations and may range from about 3 to 10
percent copper.
(b) Concentrating-grade ores. As mined, these ores will
contain from about 0.6 to about 1 or more percent copper mostly
as sulfide. They account for about 75 to 80 percent of primary
copper production in the country.
(c) Native copper ores. The only important deposits
containing native copper ores occur in Michigan.
57
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(d) Low-grade (or leaching grade) ores. These are the ores
containing significant quantities of copper as sulfide and/or
oxide and which cannot be economically concentrated by the basic
process. They may contain only a few tenths percent copper. In
mining, such ores are segregated and leached.
(e) Very low grade ores. In some cases the quantity of copper
in the country rock is so low that it is not economical to remove
the rock for copper extraction. Such deposits may be "mined" by
a leaching-in-place process.
(f) Mixed sulfide-oxide ores. These are ores in which the
sulfides and oxide minerals are present in approximately equal
amounts, and which require special treatment to yield an
economic level of recovery. Such ores may range in grade from
about 0.6 to 2 percent copper, with the bulk of them below
1 percent.
The sevoral processes used to recover the copper from the different
types of ore result in several different concentrated products
which are subsequently sent off for further processing (i.e.,
smelting and refining). The products of mining and beneficiating
processes can be classified as:
(a) High-grade ore concentrate. For the purposes of this
report, only high grade ores going directly to smelting are
considered high grade. Those going to a concentrator are
considered as a concentrating grade.
(b) Filter cake. The concentrates produced by milling
operations are always in the form of filter cake containing
about 20 percent by weight of water and, on a dry basis, from
about 20 to 35 percent copper.
(c) Native copper concentrate. Native copper ores
predominantly occur in Upper Peninsula Michigan. In the mines
currently worked in this area, native copper constitutes only
a small percentage of the value, with covellite and chalcocite
being the major copper minerals. The ores are now treated by
more or less conventional concentrating techniques to yield a
conventional filter cake.
(d) Cement copper. The product of cementation is called
cement copper. It is a relatively impure material containing
from about 70 to 90 percent copper and contaminated with such
materials as scrap iron, basic copper and iron sulfates, and
oxides.
58
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(e) Concentrated copper solution. The pregnant solutions
derived from leaching normally contain up to several grams per
liter of copper as copper sulfate. Solutions from this type of
leaching are too dilute for electrolysis, and must be treated by
an intermediate concentration process such as cementation or
solvent extraction.
The flowsheet of the copper mining and beneficiating industry shows
the various types of ores and the processing steps that are
involved in producing concentrated products. The processing
steps are numbered and the numbers are keyed with the subsequent
text in which pertinent explanations and details are presented.
59
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Copper
-.-.^•-^^ *______ *
T Aimosptwfic Ei
P Liquid Waste
~~Q Solid Waste
-------
COPPER - LOW- TO HIGH-GRADE DEPOSITS PROCESS NO. 1
Open-Pit Mining of Copper Ores
1. Function - Open-pit mining involves the removal of ore
from deposits at or near the surface by a cycle of
operations consisting of drilling blast holes, blasting
the ore, loading the broken ore onto trucks or rail
cars, and transporting it to the concentrators. (In
a few cases, blasting is not required; ore is "ripped"
by bulldozers and loaded.) Barren surface rock overlaying
the deposit must be removed to uncover the ore body;
such overburden may be up to (and, in one case, even
exceeding) 150 meters (500 feet) thick.
2. Input Materials - Explosives (ammonium nitrate-fuel oil)
0.54 Kg/metric ton (1.1 Ib./short ton) of material mined.
Water in arid areas.
3. Operating Parameters -
Temperature: Ambient
Pressure: Atmospheric
4. Utilities -
Typical Case -
o
Electric Energy: 0.22 x 10 gjoules/metric ton (6.1
kWhe/metric ton or 0.06 x 10 Btu/short ton) of ore
(0.7 percent copper, average)
Natural Gas: 0.047 cu meters/metric ton (1.5 cu ft/short
ton) of ore
Diesel Fuel: 1.13 liters/metric ton (0.27 gal/short ton)
of ore
5. Waste Streams -
Airborne particulates from blasting
Water run-off (including water used for dust control in
various mining operations)
Storage of solid overburden wastes
6. EPA Source Classification Code - None
61
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7. References
(1) Private communication with BCL staff who have visited open-
pit copper mines and consulted with the staff of various
copper companies; utility energy usage estimates were
based on experience in eight representative open-pit mines.
(2) Explosives consumption based on experience at two mines.
(3) "Development Document for Proposed Effluent Limitations
Guidelines and New Performance Standards for the Primary
Copper Subcategory of the Copper, Lead, and Zinc Segment
of the Nonferrous Metals Point Source Category", pre-
pared by Battelle's Columbus Laboratories for the
Environmental Protection Agency, Contract No. 68-01-1518,
December 1973.
62
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COPPER - LOW- TO HIGH-GRADE ORE PROCESS NO. 2
Underground Mining
1. Function - Underground mining involves the removal of ores from
deep deposits by a number of techniques, the selection of which
depends on the characteristics of the ore body. There are two
main methods, caving and supported stoping. Caving methods
used in the mining of copper include block caving used in large,
homogeneous, structurally weak ore bodies, and top-slicing for
smaller and more irregular ore bodies. Supported stoping
methods are used to mine veins and flat deposits of copper
ore. There are two types, naturally supported and artificially
supported. Natural support stoping methods include open
stoping for small ore bodies and open stoping with natural
pillar support for wider ore bodies, both of which have
structurally strong foot walls (floors in bedded deposits)
and hanging walls (roofs in bedded deposits). Artificially
supported stoping methods include shrinkage stoping for
steeply dipping tabular-shaped deposits having fairly strong
foot and hanging walls, and little waste; cut and fill stoping
for similarly shaped deposits having weak walls; and timbered
or square-set stoping methods for cases where the ore is
weak and the surrounding rock is so weak that temporary
timbered support is necessary as an interim measure prior to
filling with broken waste rock.
2. Input Materials - Nitroglycerine explosives (dynamite). About
0.5 Kg/metric ton (1 Ib/short ton) of ore mined.
3. Operating Parameters -
Temperature: Ambient
Pressure: Atmospheric
4. Utilities -
Electric Energy: Amount used varies widely depending upon
method of mining and type of ore body. Mean value estimated to
be about 0.32 x 10° joules/metric ton (9kWhe/metric ton or
0.086 x 10° Btu/short ton)
63
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5. Waste Streams -
Mine water effluent from seepage and water used in mining
such as in drilling
Storage of solid gangue
6. EPA Source Classification Code - None
References -
(1) U.S. Census of Mineral Industries, Major Group 10
(Copper, lead, zinc, gold, and silver ores) Table
3A, p 10B-11; Table 7, pp 10-22.
(2) Wideman, F. L., Chapter on Copper, Mineral Facts and
Problems, 1965 edition, Bureau of Mines, U.S. Department
of the Interior, pp 263-276.
64
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COPPER - VERY LOW-GRADE ORE DEPOSITS PROCESS NO. 3
Driving Drainage Tunnels Under Porous Ore-Bodies
for In-Pi ace Leaching
1. Function - Drainage tunnels accumulate the dilute sulfuric acid
solutions of copper leached from overlying shattered, broken,
or otherwise porous ore bodies which are too 10w grade to be
processed profitably by other methods.
2. Input Materials - Nitroglycerine explosives. About 0.5 Kg/
metric ton (1 Ib/short ton) of ore mined.
3. Operating Parameters -
Temperature: Ambient
Pressure: Atmospheric
4. Utilities -
Electric Energy: (Air compressors for drilling, etc.) Very
low on the basis of per ton of cement copper removed by
leaching methods in subsequent processing. (In-place leaching
cycles are measured in years.)
5. Haste Streams -
Mine drainage effluent
Waste rock storage
6. EPA Source Classification Code - None
7. References - .
(1) U. S. Census of Mineral Industries, Major Group 10 (Copper,
• lead, zinc, gold, and silver ores) Table 3A, p 10B-11;
Table 7, pp 10-22.
(2) Wideman, F. L., Chapter on Copper, Mineral Facts and
Problems, 1965 edition, Bureau of Mines, U: S. Department
of the Interior, pp 263-276.
65
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COPPER - HIGH-GRADE ORE PROCESS NO. 4
Crushing and Sorting
1. Function - Copper ores containing upwards of about 15 percent
copper are smelted directly; however, it is not possible to
mine only the ore deposit, some associated gangue is present
which is removed by crushing and gravity separation, usually
jigging.
2. Input Materials - High-grade copper ore with associated
gangue and water.
3. Operating Parameters - (Crushing and Jigging)
Temperature: Ambient
Pressure: Atmospheric •
4. Utilities -
o
Electric Energy: 0.11 xg10 joules/metric ton (3kWhe/
metric ton or 0.029 x 10 Btu/short ton) of ore.
5. Waste Streams -
Dust particulates in crushing
Water run off from jigs
Storage of waste rock
6. EPA Source Classification Code - None
7. References -
(1) Private communication with BCL staff who have visited mines
and consulted with producers.
(2) Wideman, F. L., Chapter on Copper, Mineral Facts and Problems,
1965 edition, Bureau of Mines, U. S. Department of the
Interior, pp 263-276.
66
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COPPER - CONCENTRATION GRADE OF SULFIDE ORE PROCESS NO. 5
Crushing, Grinding, and Classifying
1. Function - Ore containing more than about 0.4 percent
copper is concentrated for further treatment at the
smelter. To accomplish this, it is crushed, then ground
to a fineness sufficient to separate the copper
mineral particles from associated gangue, the classifier
is used to separate and return ground oversize to the
grinding mills.
2. Input Materials - Copper ore and water to grinding mills
and classifiers.
3. Operating Parameters - Crushing is a separate operation,
usually done dry. Grinding is usually done wet in a
closed circuit with a classifier.
Temperature: .Ambient
Pressure: Atmospheric
4. Utilities -
Q
Crushing: 0.11 XglO joules/metric ton (3.0 kWhe/metric
ton or 0.029 x 10 Btu/short ton) of ore.
o
Grinding and Classifying: 0.56 x 10 joules/metric
ton or 0.15 x 10° Btu/short ton) of ore.
5. Waste Streams -
Dust, particulates from the crushing operation
Water, effluents from grinding
Waste rock (associated with crushing operation at mine shaft)
6. EPA Source Classification Code - None
References -
(1) Private communication with BCL staff who have visited mines
and consulted with producers.
•
(2) Wideman, F. L., Chapter on Copper, Mineral Facts and
Problems, 1965 edition, Bureau of Mines, U. S.
Department of the Interior, pp 263-276.
67
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COPPER - CONCENTRATION GRADE OF SULFIDE ORE PROCESS iiO. 6
Flotation of Concentration Grades
of Sulfide Ores
1. Function - Copper sulfide minerals,having been freed
from attached gangue minerals such as silicates by
grinding,are separated from them by a "flotation"
technique which depends on differences in the surface
characteristics between the sulfide mineral particles
and the particles of gangue. The ground ore is agitated
by rising air bubbles in cells containing water,
various oils, and chemical reagents which cause the
sulfide mineral particles to be selectively wetted by
the oil present and become attached to the rising air
bubbles, whereupon they rise to the surface of the
cell and are scraped off.
2. Input Materials - Ground ore, water, oils, inorganic, and
organic flotation reagents such as lime and sodium
carbonate for pH regulation, pine oil and cresylic
acid as frothing agents, xanthates and fatty acids
as collectors, sodium cyanide and tannic acid as
depressants, sodium silicates as dispersants,
polysulfides as activators, and sodium monosulfides
as precipitating agents.
3. Operating Parameters - Flotation cells are operated at
ambient temperature and pressure.
4. Utilities -
8
Electric Energy: 0.23 XglO joules/metric ton (6.5 kWhe/.
metric ton or 0.062 x 10 Btu/short ton) ground ore input.
5. Haste Streams -
Slurries containing tailings, reagent losses to tailings
Solid tailings remaining after dewatering
6. EPA Source Classification Code - None
68
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7. References -
(1) Private communication with-BCL staff who have visited
mines and consulted with producers.
(2) Wideman, F.L., Chapter on Copper, Mineral Facts and
Problems, 1965 edition, Bureau of Mines, U. S.
Department of the Interior, pp 263-276.
59
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COPPER - NATIVE COPPER ORES PROCESS NO. 5
Crushing, Grinding, and Classifying
of Native Copper Ores
1. Function - Native copper ores occur in large deposits only
in the Keweenaw Peninsula of Michigan. At present, only
two shafts are in operation with a 680-metric ton
(750 short tonl - per-day pilot mill under construction.
Practice has been to crush the ore at the mine shaft
house, and reduce it further at the mill in stamp
or hammer mills. After an interim jigging operation
to remove large pieces of native copper (which go
directly to the smelter), the ore is wet ground in
closed circuit with classifiers in pebble mills in
preparation for further separation processes.
2. Input Materials - Underground mined ore and water
3< Operating Parameters -
Crushing (Dry)
Wet grinding and classification
Temperature: Ambient
Pressure: Atmospheric
4. Utilities -
o
Crushing: 0.1 x 10 joules/metric ton (3.0. kWhe/metric
ton or 0.029 x 10° Btu/short ton) of ore.
w
Grinding andgClassifying: 0.56 x 10 joules/metric ton
or 0.15 x 10 Btu/short ton) of ore.
5. Waste Streams -
Dust, particulates from the crushing operation
Water, effluents from grinding
Waste rock (associated with crushing operation at mine shaft)
6. EPA Source Classification Code - None
70
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7. References -
(1) Splide, D. E., The Keweenaw Venture: Homes-take's Search
for Native Copper; paper given at the 104th AIME Annual
Meeting, New York Hilton Hotel, New York, N. Y.,
February 17, 1975.
(2) Private communication with BCL staff who have visited
mines and consulted with producers.
(3) Wideman, F. L., Chapter on Copper, Mineral Facts and
Problems, 1965 edition, Bureau of Mines, U. S. Department
of the Interior, pp 263-276.
71
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COPPER - NATIVE COPPER ORES PROCESS NO. 6
Flotation of Ground Native Copper Ores
1. Function - The tailing from the coarse gravity concentrators
are reground fine enough to free minute particles of native
copper from adhering gangue. The finely ground ore is agi-
tated by rising air bubbles in cells containing water,
various oils, and organic and inorganic reagents which
cause the surface of the copper particles to be hydro-
phobic and aerophilic, and are thus selectively wetted by
the oil and become attached to the rising air bubbles,
after which they rise to the surface where they are scraped
off.
2. Input Materials - Ground ore, water, oils, Inorganic, and
organic flotation reagents.
3. Operating Parameters - Flotation cells are operated at
ambient temperature and pressure.
4. Utilities -
Electric Energy: 0.23 xJGB joules/metric ton (fi.s i<^=/ -
metric ton or 0.062 x 10 3tu/short ton) ground ore input
5. Waste Streams -
Slurries containing tailings, reagent losses to tailings
Solid tailings remaining after dewatering
6. EPA Source Classification Code - None
7. References -
(1) Private communication with BCL staff who have visited
mines and consulted with producers.
(2) Wideman, F. L., Chapter on Copper, Mineral Facts and Problems,
1965 edition, Bureau of Mines, U. S. Department of the
Interior, pp 263-276.
72
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COPPER - NATIVE COPPER ORES PROCESS NO. 7
Gravity Concentration .
1. Function - Native copper deposits of the Keweenaw Peninsula
of Michigan occur in amygdaloid and conglomerate beds of
the Keweenawan Portage Lake Lava series. It is disseminated
throughout the conglomerate in varying degrees of fineness;
the amygdaloidal copper deposits tend to be formed in almond-
shaped vesticles of relatively large size. Native copper,
as it occurs in the deposits, is quite pure and malleable,
and thus the large lumps and coarse particles of native copper
occurring in these deposits do not lend themselves to fine
grinding. Accordingly, the copper in the deposits is
separated from the waste rock in stages, the large lumps
and coarse particles are separated first by gravity
concentration. Large pieces, liberated in the stamp and
hammer mills, are separated first in jigs. The overflow
from the jigs is coarse ground and separated by tabling.
Remaining fine particles of copper in the table tailings
discharge are released by further grinding and separated in
flotation cells.
2. Input Materials - Native copper ore and water.
3. Operating Parameters - Jigs and tables are operated at
ambient temperature and pressure.
4. Utilities -
g
Electric Energy: 0.14 xg10 joules/metric ton (9kWhe/
metric ton or 0.038 x 10 Btu/short ton) of ore.
5. Waste Streams -
Water overflow in jigs and tables
6. EPA Source Classification Code - Hone
7. References -
(1) Splide, D. E., The Keweenaw Venture: Homestake's Search
for Native Copper; paper given at the 104th AIME Annual
Meeting, New York Hilton Hotel, New York, N. Y.,
February 17, 1975.
73
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(2) Private communication with BCL staff who have visited
mines and consulted with producers.
(3) Wideman, F. L., Chapter on Copper, Mineral Facts and
Problems, 1965 edition, Bureau of Mines, U. S. Department
of the Interior, pp 263-276.
74
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COPPER - LOW-GRADE SULFIDE AND OXIDE ORES PROCESS NO. 8
Crushing of Low-Grade Ore for Leaching
1. Function - In handling copper ores from open pit mines,
those having more than 0.4 percent copper are concentrated,
those having less than this amount are deposited in waste
rock dumps and leached. In heap leaching (mainly used
on oxide ores), some of the ore may require crushing, and
in some cases, large rock pieces require blasting, to
insure contact of the leach solution with finely
disseminated copper minerals.
2. Input Materials - Low-grade oxide or sulfide copper ore.
3. Operating Parameters -
Tsmperature: Ambient
Pressure: Atomospheric
4. Utilities -
Electric Energy: Very low. In the four open pit mines
that produce most of the cement copper in the U.S., waste
ore for leaching is not crushed; neither is it crushed in
a typical heap leaching operations on soft oxide ore
produced from an open-pit mine at the rate of 7,260
metric tons (8,000 short tons) of ore per day.
5. Waste Streams -
Dust, particulates from dumping ore in heaps or dumps;
also from a limited amount of crushing.
6. EPA Source Classification Code - None
7. References -
(1) Power, Kenneth L., Operation of the First Commercial
Copper Liquid Ion Exchange and Electrowinning Plant,
Proc., Extractive Metallurgy Division Symposium on
Copper Metallurgy, Denver, February 15-19, 1970;
The Metallurgical Society of the AIME, New York,
N. Y., 1970, pp 1-26.
(2) Private communication with BCL staff who have visited
mines and consulted with producers.
75
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(3) Wideman, F. L., Chapter on Copper, Mineral Facts and
Problems, 1965 edition, Bureau of Mines, U.S.
Department of the Interior, pp 263-276.
76
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COPPER - LOW-GRADE SULFIDE AND OXIDE ORES PROCESS NO. 9
Dump and Heap Leaching
1. Function - Subore grades of copper from open pit mines having
less than 0.4 percent copper are deposited in waste rock
heaps (dumps) and leached. The leaching cycle in dump
leaching is measured in years. Heap leaching is used" to
recover copper from weathered ore, and in some cases
from material from mine dumps. The material is placed in
alternately fine and coarse layers in prepared water-tight
basins up to a thickness of about 6.1 meters (20 feet).
In a typical heap-leaching operation, the spent
leaching solution containing sulfuric acid, with water
additions, is recycled; additions of sulfuric acid to
this solution are made during the initial stages of a
6-month leach cycle.
2. Input Materials - Broken ore, spent leach, water, and dilute
sulfuric acid sometimes ferric sulfate and bacteria. Various
bacteria such as thiobacillus ferrooxidans are used to
oxidize ferric iron and reduce sulfur compounds. Amounts
of sulfuric acid used will vary. A typical amount would
be 12.5 Kg/metric ton (25 Ib/short ton) of mill feed.
3. Operating Parameters - Leach dumps and heaps are open to the
weather; ambient temperature and
4. Utilities -
8
Electric Energy: fi0.2 x 10 joules/metric ton (5.5 KWhe/metric
ton or 0.052 x 10 Btu/short ton) of ore.
5. Waste Streams -
Storage of spent leaching solutions (recycled), spills
Storage of solid leached material 'in dumps and heaps
6. EPA Source Classification Code - None
7. References -
(1) Power, Kenneth L., Operation of the First Commercial
Copper Liquid Ion Exchange and Electrowinning Plant,
Proc., Extractive Metallurgy Division Symposium
on Copper Metallurgy, Denver, February 15-19,
1970; The Metallurgical Society of the AIME, New
York, N.Y., 1970, pp 1-26.
77
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(2) Private communication with BCL staff who have visited mines
an'd consulted with producers.
(3) Wideman, F. L., Chapter on Copper, Mineral Facts and
Problems, 1965 edition, Bureau of Mines, U. S. Department
of the Interior, pp 263-276.
78
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COPPER - VERY LOW-GRADE ORE IN SITU PROCESS NO. 10
Leaching in Place
1. Function - Lean ore bodies containing less than 0.4 percent
copper (as sulfide or oxides) which are broken or shattered
to allow contact with air and water are leached in place; the
sulfide minerals are exposed and oxidized by alternate and
intermittent contact with air and water to form (along with
any.oxides present) a copper sulfate leach solution which is
accumulated in drainage tunnels driven under the ore.
2. Input Materials - Explosives for tunnel construction and to
achieve permeation of the ore body by leach solutions,
water, spent leach solution, dilute sulfuric acid, sometimes
ferric sulfate and bacteria (to oxidize metallic sulfides
to water soluble sulfates).
3. Operation Parameters - Ore bodies leached by in-place methods
are open to the weather; temperature and pressure are
ambient, the leach cycle is measured in years.
4. Utilities -
Electric Energy: (Pumping) 0.2 x 108 joules/metric ton
(5.5 kWhe/metric ton or 0.052 x 106 Btu/short ton) of ore.
5. Waste Streams -
Stripped solutions are ponded for recycling. Spills.
Areas of in-place leached shattered ore which may require
reclamation.
6. EPA Source Classification Code - None
7. References -
(1) Power, Kenneth L., Operation of the First Commercial
Copper Liquid Ion Exchange and Electrowinning Plant,
Proc., Extractive Metallurgy Division Symposium on
Copper Metallurgy, Denver, February 15-19, 1970; The
Metallurgical Society of the AIME, New York, N. Y.,
1970, pp 1-26.
79
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(2) Private communication with BCL staff who have visited
mines and consulted with producers.
(3) Wideman, F. L., Chapter on Copper, Mineral Facts and
Problems, 1965 edition, Bureau of Mines, U. S. Department
of the Interior, pp 263-276.
80
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LOW GRADES OF SULFIDE ORE
COPPER - LOW GRADES OF OXIDE ORE PROCESS NO. 11
VERY LOW GRADES OF ORE IN SITU
Cementation of Copper From Leach Solutions Obtained
in Dump and Heap Leaching
1. Function - Copper in solution in the dilute acid leach liquor
is precipitated by replacement with iron. In typical practice,
the leach liquor, containing 0.5-1.5 g/1 of copper, flows
through launders containing scrap iron (usually detinned steel
scrap or burned tin cans) and plates out a loosely adherent
"cement" copper on the iron surfaces which, in a later cycle,
is washed off these surfaces into a settling basin. Auto-
matically controlled cone precipitators which "self clean" the
copper precipitates have been introduced in the industry
during the late I9601s.
2. Input Materials - Leach solution, scrap iron, detinned steel
scrap, or burned tin cans. Water jets or sprays for removing
cement copper from the iron surfaces.
3. Operating Parameters -
Temperature: Ambient
Pressure: Atmospheric
4. Utilities - 8
Electric Energy: (Pumping —includes leaching) 0.2 XglO
joules/metric ton (5.5 kWhe/metric ton or 0.052 x 10
Btu/short ton) of ore. 0.16 x 108 joules/kilograms (4.3
kWhe/kilogram or 0.020 x 10° Btu/pound of cement copper
(-0.3 percent copper, 30 percent recovery.)
5. Waste Streams -
Stripped solutions are ponded for recycling. Spills.
6. EPA Source Classification Code - None
7. References - .
(1) Pings, W. B., and Rau, Earl L., Recent Trends in Copper
Metallurgy, Mineral Industries Bulletin, Colorado School
of Mines Research Foundation, Inc., Vol II, No. 4, July,
1968, pp 1-12.
81
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COPPER - LOW GRADES OF SULFIDE AND OXIDE ORE PROCESS NO. 12
Solvent Extraction (Liquid Ion Exchange)
1. Function - Leach liquors containing copper in weak acid solution
may be selectively removed from the solution by contact with a
liquid ion-exchange reagent. In the two commercial installations
in the United States, copper in the leach liquors is extracted
with a 6-7-percent-by-volume solution of LIX-64 (a proprietary
organic ion-exchange compound produced by General Mills) in
a kerosene solvent. In the extraction reaction, the hydrogen
ions of the reagent are replaced with copper ions. In a
following stripping cycle, the copper in the organic medium
is stripped with acid electrolyte from the electrolytic recovery
section of the plant. In this stripping cycle, the copper ions
are reexchanged with hydrogen ions, thus regenerating the
ion exchange reagent for recycling to the extraction system,
and concentrating the electrolyte. Because the ion-exchange
reagent is highly selective, the enriched electrolyte is
essentially impurity free.
2. Input Materials - Leach solution, liquid ion-exchange reagent
in an inert organic solvent such as kerosene (both recycled).
Make-up water. Dilute sulfuric acid additions.
3. Operating Parameters - Depending on the climate, the extraction
circuit may require some heat input (via heat exchangers)
during the winter months to insure proper separation of the
organic solution of ion exchange reagent and the aqueous
electrolyte.
Temperature: 27 C (80 F)
Pressure: Atmospheric
4. Utilities -
o
Electric Energy: About 0.04 x 10 joules/metric ton (1.1
kWhe/metric ton or 0.010 x 10° Btu/short ton) of copper
produced, required for pumping of solutions, and operation
of flotation cells (without additional reagents) to
remove entrained organic ion-exchange reagent from the
pregnant electrolytic which, if present, causes -copper to
precipitate as sponge or cement copper rather than as a dense
deposit.
82
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5: Waste Streams -
Possible seepage losses under dumps and heaps
Seepage losses or spills from pregnant liquor pond
Spillage of dilute sulfuric acid
Filtered slimes from pregnant solution
Waste rock in heaps and dumps
6. EPA Source Classification Code - None
7. References -
(1) Power, Kenneth L., Operation of the First Commercial
Copper Liquid Ion Exchange and Electrowinning Plant,
Proc., Extractive Metallurgi Division Symposium on
Copper Metallurgy, Denver, February 15-19, 1970; The
Metallurgical Society of the AIME, New York, N. Y.,
1970, pp 1-26.
(2) Private communication with BCL staff who have visited mines
and consulted with producers.
(3) Wideman, F. L., Chapter on Copper, Mineral Facts and
Problems, 1965 edition, Bureau of Mines, U. S. Department
of the Interior, pp 263-276.
83
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COPPER - MIXED SULFIDE AND NONSULFIDE ORES PROCESS NO. 5
Crushing, Grinding, and Classifying
1. Function - Ore containing more than about 0.4 percent copper is
concentrated for further treatment at the smelter. To
accomplish this, it is crushed, then ground to a fineness
sufficient to separate the copper mineral particles from
associated gangue, the classifier is used to separate and
return ground oversize to the grinding mills.
2. Input Materials - Copper ore and water to grinding mills and
classifiers.
3. Operating Parameters - Crushing is a separate operation, usually
done dry. Grinding is usually done wet in a closed circuit
with a classifier.
Temperature: Ambient
Pressure: Atmospheric
4. Utilities - 8
Crushing: 0.11 xg10 joules/metric ton 93.0 kWhe/metric
ton or 0.029 x 10 Btu/short ton) of ore.
Q
Grinding and Classifying: 0.56 x 10 joules/metric ton
(15.5 kWhe/metric ton or 0.15 x 106 B.tu/short ton) of ore.
5. Haste Streams -
Dust, particulates from the crushing operation
Water, effluents from grinding
Waste rock (associated with crushing operation at mine shaft)
6. EPA Source Classification Code - None
7. References - ' .
(1) Private communication with BCL staff who have visited mines
and consulted with producers.
(2) Wideman, F. L., Chapter on Copper, Mineral Facts and Problems,
1965 edition, Bureau of Mines-, U. S. Department of the
Interior, pp 263-276.
84
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COPPER - MIXED SULFIDE AND NONSULFIDE
(OXIDE OR SILICATE) ORESPROCESS NO. 13
Vat Leaching in the L-P-F (Leaching-Precipitation-
Flotati'on) Process for Mixed Sulfide. and Nonsulfide~Qres
1. Function - Copper oxide minerals which are present in mixed ores
are only partially amenable to concentration by the flotation
process. The L-P-F (Leaching-Precipitation-Flotation) process
developed to treat these mixed ores comprises three steps:
(1) vat or percolation leaching with sulfuric acid to put the
oxide minerals in the ore in solution, (2) precipitating
the dissolved copper as cement copper (or alternatively
transferring the pregnant leach solution to the electrolytic
refining plant), and (3) recovery of the cement copper and
copper sulfide minerals by flotation (Cement copper, like
the sulfide minerals, is easily concentrated by flotation
methods).
2. Input Materials - Ground "mixed" copper ore, dilute sulfuric
acid, water.
3. Operating Parameters -
Temperature: Ambient
Pressure: Atmospheric
4. Utilities -
n
Electric Energy, Pump: 0.2 x 10 joules/metric ton (5.5
kWhe/metric ton or 0.052 x 10° Btu/short ton) of ore
(includes also associated agitated tank leaching residue
washing-pumping energy)
5. Waste Streams -
Possible leakage in spent leach solution ponds. Both the
leaching liquid and the leached solids are further processed.
6. EPA Source Classification Code - None
7. References -
(1) Pings, W. B., and Rau, Earl L., Recent Trends in Copper
Metallurgy, Mineral Industries Bulletin, Colorado School
of Mines Research Foundation, Inc., Vol II, No. 4, July,
1968, pp 1-12.
85
-------
(2) Private communication with BCL staff who have visited mines
and consulted with producers.
(3) Wideman, F. L., Chapter on Copper, Mineral Facts and Problems,
1965 edition, Bureau of Mines, U. S. Department of the
Interior, pp 263-276.
86
-------
COPPER - MIXED SULFIDE AND NONSULFIDE
(OXIDE AND SILICATE)~QRETPROCESS NO. 14
Residue Washing of Ground Vat Leached Ore in the
L-P-F (Leaching-Precipitation-Flotation) Process
1. Function - After the leaching cycle, copper in solution
in dilute sulfuric acid is in contact with ground ore which
still contains ground unreacted copper sulfide minerals.
The ore is washed free of the copper leach by countercurrent
washing.
2. Input Materials - water
3. Operating Parameters -
Temperature: Ambient
Pressure: Atmospheric
4. Utilities -
•~\
Electric Energy: Pumping: 0.20 xfi!0° joules/metric ton
(5.5 kWhe/metric ton or 0.052 x 10 Btu/short ton) of
ore (includes energy required on vat leach solution and
agitated tank leaching operations)
5. Waste Streams -
Wash waters representing various stages of washing are stored
in tanks. Possibility of spillage, leaks, etc.
6. EPA Source Classification Code - None
7. References -
(1) Pings, W. B., and Rau, Earl L., Recent Trends in Copper
Metallurgy, Mineral Industries Bulletin, Colorado School
of Mines Research Foundation, Inc., Vol II, No. 4, July,
1968, pp 1-12.
(2) Private communication with BCL staff who have visited mines
and consulted with producers.
87
-------
(3) Wideman, F. L., Chapter on Copper, Mineral Facts and Problems,
1965 edition, Bureau of Mines, U. S. Department of the
Interior, pp 263-276.
-------
COPPER - MIXED SULFIDE AND NONSULFIDE
(OXIDE AND SILICATE) ORESPROCESS NO. 6
Flotation of Reground Mixed Ore Residue
After Vat Leaching and Hashing
1. Function - The copper sulfide minerals remaining in the leached
and washed residue are reground to free these minerals from any
attached gangue and then separated from them by a "flotation"
technique which depends on the differences in the surface
characteristics between the sulfide mineral particles and the
particles of gangue. The ground ore is agitated by rising air
bubbles in cells containing water, various oils, and chemical
reagents which cause the sulfide mineral particles to be
selectively wetted by the oil present and become attached to
the rising bubbles, whereupon they rise to the surface and are
scraped off.
2. Input Materials - Reground washable residue from vat leaching,
waters, oils, inorganic, and organic flotation reagents.
3. Operating Parameters - Flotation cells are operated at ambient
temperature and pressure.
4. Utilities -
g
Electric Energy: 0.23 x 10 joules/metric ton (6.5
kWhe/metric ton or 0.062 x 10° Btu/short ton) of ground
ore input.
5. Waste Streams -
Slurries containing tailings, reagent losses to tailings
Solid tailings remaining after dewatering
6. EPA Source Classification Code - None
7. References -
(1) Pings, W. B., and Rau, Earl L., Recent Trends in Copper
Metallurgy, Minerals Industries Bulletin, Colorado School
of Mines Research Foundation, Inc., Voi II, No. 4, July,
1968, pp 1-12.
89
-------
COPPER - MIXED SULFIDE AND NONSULFIDE
(OXIDE AND SILICATE) ORESPROCESS NO. 15
Agitated Tank Leaching of Slimes from the Classifier
in the Grinding Circuits with Pregnant Leach Liquor
from the Vat Leaching Operation irTthe L-P-F (LeachTng-
Precipitation-Flotation) Process
1. Function - Slimes produced in the course of-grinding and regrind-
ing would fill the interstices of the ground material in the
leaching vat and prevent effective percolation of the leach
liquor through the ground ore. To prevent this, and still
obtain the copper values in very finely divided ore, the
slimes are leached separately with the pregnant vat leaching
liquor in an agitated tank leach.
2. Input Materials - Pregnant leach liquor from the vat leach and
slimes from the classifiers in the grinding operations.
3. Operating Parameters -
Temperature: Ambient
Pressure: Ambient
4. Utilities -
Electric Energy; Pumpingg—• includes vat leaching and
residue washing Og2Q x 1C joules/metric ton (5.5 kWhe/metric
ton or 0.052 x'lO Btu/short ton) of ore
5. Waste Streams -
Both the leach liquor product and the leached slimes are further
processed
Spillage and leaks in equipment
6. EPA Source Classification Code - None
7. References -
(1) Pings, W. B., and Rau, Earl L., Recent Trends in Copper
Metallurgy, Minerals Industries Bulletin, Colorado School
of Mines Research Foundation, Inc., Vol II, Mo. 4, July,
1968, pp 1-12.
90
-------
(2) Private communication with BCL staff who have visited mines
and consulted with producers.
(3) Wideman, F. L., Chapter on Copper, Mineral Facts and Problems
1965 edition, Bureau of Mines, U. S. Department of the
Interior, pp 263-276.
91
-------
COPPER - MIXED SULFIDE AND NONSULFIDE
(OXIDE AND SILICATE) ORESPROCESS NO. 11
Cementation of the Pregnant Liquor from the
Agitation Leaching Operation in the L-P-F (Leaching-
Precipitation-Flotation) Process
1. Function - The pregnant liquor from the agitated leaching tanks
is mixed with sponge iron which precipitates the copper out of
solution as cement copper; in a later step, the precipitated
cement copper is separated and concentrated by flotation methods,
2. Input Materials - Pregnant leach solution and sponge iron
3. Operating Parameters -
Temperature: Ambient
Pressure: Atmospheric
4. Utilities -
Electric Energy; Pumping —includes entire leaching and
cementation processing cycle 0.20 x 10" joules/metric
ton (5.5 kWhe/metric ton or 0.052 x 106 Btu/short ton)
of ore. 0.15 x 10° joules/kilogram (4.3 kWhe/kilogram
or 0.02 x 10° Btu/pound) of cement copper.
5. Waste Streams -
Leakage and spillage from spent liquor ponds
Solids are further processed
6. EPA Source Classification Code - None
7- References -
(1) Pings, W. B., and Rau, Earl L., Recent trends in Copper
Metallurgy, Mineral Industries Bulletin, Colorado School
of Mines Research Foundation, Inc., Vol II, No. 4, July,
1968, pp 1-12.
92
-------
(2) Private communication with BCL staff who have visited mines
and consulted with producers.
(3) Wideman, F. L., Chapter on Copper, Mineral Facts and Problems,
1965 edition, Bureau of Mines, U. S. Department of the
Interior, pp 263-276.
93
-------
COPPER - MIXED SULFIDES AND NONSULFIDES
(OXIDE AND SILICATE) ORESPROCESS NO. 6
Flotation of Cement Copper after Precipitation with
Sponge Iron from Pregnant Agitated Leach Tank Liquor
in the L-P-F (Leaching-Precipitation-Flotation) Process
1. Function - Cement copper from the precipitation process responds
to flotation in much the same manner as sulfide minerals.
Accordingly, it is concentrated by flotation .methods. Usually
it is mixed with the sulfide flotation product obtained from the
vat leaching residue and shipped to the smelter.
2. Input Materials - Cement copper from precipitation operation,
water, oils, and flotation reagents.
3. Operating Parameters - Flotation cells are operated at ambient
temperature and pressure.
4. Utilities -
Electric Energy: 0.23 xfi108 joules/metric ton (6.5 kWhe/
metric ton or 0.062 x 10 Btu/short ton) of ground ore input.
5. Waste Streams -
Sturries containing tailings* reagent losses to tailings
Solid tailings remaining after dewatering
6. EPA Source Classification Code - None
7. References -
(1) Pings, W. B., and Rau, Earl L., Recent Trends in Copper
Metallurgy, Mineral Industries Bulletin, Colorado School
of Mines Research Foundation, Inc., Vol II, No. 4, July,
1968,. pp 1-12.
94
-------
(2) Private communication with BCL staff who have visited mines
and consulted with producers.
(3) Wideman, F. L., Chapter on Copper. Mineral Facts and Problems,
1965 edition, Bureau of Mines, U. S. Department of the
Interior, pp 263-276.
95
-------
Gold
The consumption of gold in the United States exceeds domestic pro-
duction of this commodity by about five fold. U.S. reserves of gold
are fairly large but of low grade so that production is not likely to
equal consumption even with an intensified mining effort brought about
by increasing gold prices. Most of the gold reserve in the U.S. is in
lode deposits such as in the Homestake, South Dakota and Carl in, Nevada,
ore bodies, but considerable gold also is in reserve in copper deposits
as a dilute part of the mineralization. In fact, about half of the U.S.
primary production of gold is as byproduct from copper.ores.
When the rocks of a lode gold deposit are dissolved and disintegrated
by "weathering" (i.e., rain, freezing, erosion, etc.), the gold par-
ticles resistant to these forces are liberated and washed into water-
ways. This is the so-called "placer" gold ore and is distinguished
from "lode" ore in which the gold is still associated, encapsulated,
etc., in other rocks.
Much of the gold recovered in the U.S. from both lode and placer mining
operations is in the form of impure, but nevertheless, metallic gold.
From placer operations the product may be a "heavy sand" concentrate
which is very rich in metallic gold, or indeed from some placers, the
product may be only metallic gold with attendent impurities (e.g.,
silver). Leaner ores from placers, or some of the higher gold content
gangue material (i.e., middlings), may be sent through an amalgamation
process to result in the end product, gold amalgam. Crude gold bullion
may be obtained by retorting gold amalgam,which process liberates gold
from the mercury of the amalgam. Lode gold ore concentration product
may also be gold amalgam or gold bullion obtained from retorting amalgam.
The products of gold ore mining and concentrating are:
(a) Rich gold ore concentrate
(b) Gold amalgam or crude gold bullion from retorting amalgams
(c) Concentrated gold solutions
(d) "Black" powder, precipitated gold powder.
As previously stated, gold ores may be broadly categorized as placer and
lode types. The mining methods used for the recovery of these are placer
mining and conventional open pit or underground mining (for lode ores).
Wet gravity methods of concentrating, flotation, leaching, and various
solution extraction techniques are some of the processes additionally
used in the recovery of gold. These methods are depicted in sequential
order on the accompanying process flow diagram and are described in the
following paragraphs. The numbers in the process blocks on the diagram
are keyed to the corresponding process descriptive text.
96
-------
Gold
To R«fining
Yo Refining
4
Grinding.
Amalgamation
o
To Electiowinning
| Atmospheric Emissions
y Liquid Waste
To Refining
-------
GOLD - PLACER DEPOSITS PROCESS NO. 1
Placer Mining
1. Function - Placer mining comprises the excavation and delivering
of auriferous gravel from alluvial deposits to a washing plant
for the recovery of its gold content. The type of deposit
determines the particular placer mining method used: (1) large
stream deposits may be mined by floating dredges combining
digging, washing, gravity separation, and tailings disposal in
a self contained unit, (2) hydraulic mining or gravel pumping
is another method which consists of excavating and breaking
up a gravel bank with hydraulic monitors, washing the disinte-
grated material into a sump, elevating this material to a line
of sluice boxes with a gravel pump, where the gold is recovered
by slucing, (3) Excavation by power shovel or dragline, and
(4) small-scale hand methods.
2. Input Materials - Auriferrous gravel from alluvial deposits,
water under pressure.
3. Operating Parameters -
Temperature: Ambient
Pressure: Atmospheric
4. Utilities - Includes washing, screening and gravity separation
The amount of power used depends upon the method of placer mining
and concentration. For dredging: 0.046 x 10° joules/metric ton
(1.27 kWhe/metric ton or 0.012 x 10° Btu/short ton) of placer
gravel for excavation, delivery, washing, and gravity concentra-
tion. For gravel pumping: 0.086 x 10 joules/metric ton (2.38
kWhe/metric ton or 0.023 x 10° Btu/short ton) of placer gravel
for excavation, collection into sump, elevation to the sluice
boxes, and concentration by sluicing.
5. Waste Streams -
Water run from hydraulicking, tailings run from dredging, etc.
Gravel remaining on tailings after concentration.
98
-------
6. EPA Source Classification Code - None
7. References -
(1) Private communication with members of the BCL staff who
have consulted with producers on energy requirements
and specifics of operation.
(2) Ageton, R. W., Chapter on Gold, Mineral Facts and
Problems, 1970; Bureau of Mines, U. S. Department of the
Interior, Washington, D.C., pp 563-572.
(3) Ryan, J. Patrick; Chapter on Gold, Mineral Facts and
Problems, 1965, Bureau of Mines Bulletin 630, Bureau
of Mines, U. S. Department of the Interior, Washington,
D.C., pp 387-397.
(4) Development Document for Effluent Guidelines and Standards
of Performance, Ore Mining and Dressing Industry (Draft),
U. S. Environmental Protection Agency, Washington, D.C.
(Prepared by the Calspan Corp., Buffalo, N. Y.).
99
-------
GOLD - PLACER DEPOSITS PROCESS NO. 2
Hashing and Screening
1. Function - The function of washing and screening of auriferrous
gravel is to separate sand, small rocks, heavy minerals, and
gold from barren rock oversize by washing it through rotating
cylindrical screens (washing trommels).
2. Input Materials - Auriferrous gravel and water
3. Operating Parameters -
Temperature: Ambient
Pressure: Atmospheric
4. Utilities - (Includes dredging and gravity separation)
The amount of power used depends upon the method of placer mining
and concentration. For dredging: 0.046 x 108 joules/metric ton
(1.27 kWhe/metric ton or 0.012 x 10° Btu/short ton) of placer
gravel for excavation, delivery, washing, and gravity concentra-
tion. For gravel pumping: 0.086 x 10° joules/metric ton (2.38
kWhe/metric ton or 0.023 x 10° Btu/short ton) of placer gravel
for excavation, collection into a sump, elevation to the sluice
boxes, and concentration by sluicing.
5. Waste Streams -
Dust where trommel ing is done dry as in some areas of the U.S.
Southwest.
Water emissions from washing trommel.
Barren rock oversize from washing operations.
6. EPA Source Classification Code - None
7. References -
(1) Private communication with members of the BCL staff who
have consulted with producers on energy requirements
and specifics of operation.
100
-------
(2) Ageton, R. W., Chapter on Gold, Mineral Facts and
Problems, 1970; Bureau of Mines, U. S. Department of
the Interior, Washington, D.C., pp 563-572.
(3) Ryan, J. Patrick; Chapter on Gold, Mineral Facts and
Problems, 1965, Bureau of Mines Bulletin 630, Bureau
of Mines, U. S. Department of the Interior, Washington,
D.C., pp 387-397.
(4) Development Document for Effluent Guidelines and
Standards of Performance, Ore Mining and Dressing
Industry (Draft), U. S. Environmental Protection
Agency, Washington, D.C. (Prepared by the Calspan
Corp., Buffalo, N. Y.).
101
-------
GOLD - PLACER DEPOSITS PROCESS NO. 3
Gravity Separation
1. Function - Gold, with its high density, is easily separated
from the lighter weight gravel by gravity concentration methods;
these include sluice boxes operated in conjunction with placer
mining, and jigs and tables.
2. Input Materials - Auriferrous gravel from alluvial deposits,
water under pressure.
3. Operating Parameters -
Temperature: Ambient
Pressure: Atmospheric
4. Utilities - (Includes dredging, washing and screening)
The amount of power used depends upon the method of olacer
mining and concentration. For dredging: 0.046 x 10 joules/
metric ton (1.27 kWhe/metric ton or 0.012 x 106 Btu/short ton)
of placer gravel for excavation, delivery, washing, and gravity
concentration. For gravel pumping: 0.086 x 10 joules/metric
ton (2.38 kWhe/metric ton or 0.023 x 10° Btu/short ton) of
placer gravel for excavation, collection into a sump, elevation
to the sluice boxes, and concentration by sluicing.
5. Waste Streams -
Dusting in areas of U.S. Southwest where air, rather than water,
pulsations are used in dry gravity-concentration processes
Barren gravel waste from gravity concentration
6. EPA Source Classification Code - None
7. References -
(1) Private communication with members of the BCL staff who have
consulted with producers on energy requirements and specifics
of operation.
102
-------
(2) Ageton, R. W., Chapter on Gold, Mineral Facts and
Problems, 1970; Bureau of Mines, U. S. Department of the
Interior, Washington, D.C., pp 563-572.
(3) Ryan, J. Patrick; Chapter on Gold, Mineral Facts and
Problems, 1965, Bureau of Mines Bulletin 630, Bureau
of Mines, U. S. Department of the Interior, Washington,
D.C., pp 387-397.
(4) Development Document for Effluent Guidelines and Standards
of Performance, Ore Mining and Dressing Industry (Draft),
U. S. Environmental Protection Agency, Washington, D.C.
(Prepared by the Calspan Corp., Buffalo, N. Y.).
103
-------
GOLD - PLACER DEPOSITS PROCESS NO. 4
Grinding and Amalgamation
1. . Function - Current practice (in the single mill in Colorado
which uses an amalgamation process) involves crushing and
grinding of lode ore, separation of the gold-bearing black
sands by jigging, and final concentration of the gold in the
sands by batch amalgamation with mercury in a barrel amalgama-
tor. In barrel amalgamation, the ore is gently ground in a
cylindrical rod or ball mill for several hours to bring the
gold and mercury into intimate contact. The resulting amalgam
is collected in a gravity trap.
2. Input Materials - Ground ore from a gold bearing lode deposit,
mercury and water.
3. Operating Parameters -
Temperature: Ambient
Pressure: Atmospheric
4. Utilities -
0
Electric Energy: crushing and grinding; 0.56 x 10 joules/
metric ton (15 kWhe/metric ton or 0.15 x 10° Btu/short ton) of
ore.
5. Waste Streams -
Water containing suspended solids from amalgamation plant to tailing
.pond (copper, iron, mercury, and zinc in solution)
6. EPA Source Classification Code - None
7. References -
/
(1) Private communication with members of the BCL staff who
have consulted with producers on energy requirements and
specifics of operation.
(2) Ageton, R. W., Chapter on Gold, Mineral Facts and Problems,
1970; Bureau of Mines, U. S. Department of the Interior,
Washington, D.C., pp 563-572.
104
-------
(3) Ryan, J. Patrick; Chapter on Gold, Mineral Facts and Prob-
lems, 1965, Bureau of Mines Bulletin 630, Bureau of Mines,
U. S. Department of the Interior, Washington, D.C., pp 387-
397.
(4) Development Document for Effluent Guidelines and Standards
of Performance, Ore Mining and Dressing Industry (Draft),
U. S. Environmental Protection Agency, Washington, D.C.
(Prepared by the Calspan Corp., Buffalo, N. Y.)
105
-------
GOLD - PLACER DEPOSITS PROCESS NO. 5
Retorting
1. Function - Gold dissolved in mercury is recovered by distilling
off the mercury in a retort.
2. Input Materials - Gold amalgam
3. Operating Parameters -
The retort is heated to vaporize the mercury constituent [b.p.
357 C (675 F)]. The pressure is atmospheric.
4. Utilities -
The heat required is relatively low since only small amounts of
gold and mercury are handled relative to the amount of ore mined,
Fuel to supply heat is usually transported to the site.
5. Waste Streams -
Mercury emissions
6. EPA Source Classification Code - None
7. References -
(1) Private communication with members of the BCL staff who
have consulted with producers on energy requirements and
specifics of operation.
(2) Ageton, R. W., Chapter on Gold, Mineral Facts and
Problems, 1970; Bureau of Mines, U. S. Department of
the Interior, Washington, D.C., pp 563-572.
(3) Ryan, J. Patrick; Chapter on Gold, Mineral Facts and
Problems, 1965, Bureau of Mines Bulletin 630, Bureau of
Mines, U. S. Department of the Interior, Washington,
D.C., pp 387-397.
106
-------
(4) Development Document for Effluent Guidelines and Standards
of Performance, Ore Mining and Dressing Industry (Draft.),
U. S. Environmental Protection Agency, Washington, D.C.
(Prepared by the Calspan Corp., Buffalo, N. Y.).
107
-------
GOLD - LODE DEPOSITS PROCESS NO. 6
Underground Mining
1. Function - Underground mining involves the removal of ores from
deep deposits by a number of techniques, the selection of which
depends on the characteristics of the ore body. There are two
main methods, caving and supported stoping. Caving methods used
in the mining of gold include block caving used in large,
homogeneous, structurally weak ore bodies, and top-slicing for
smaller and more irregular ore bodies. Supported stoping
methods are used to mine veins and flat deposits of gold. There
are two types, naturally supported stoping methods include open
stoping for small ore bodies and open stoping with natural
pillar support for wider ore bodies, both of which have
structurally strong foot walls (floors in bedded deposits) and
hanging walls (roofs in bedded deposits). Artificially supported
stoping methods include shrinkage stoping for steeply dipping
tabular-shaped deposits having fairly strong foot and hanging
walls, and little waste; cut and fill stoping for similarly
shaped deposits having weak walls; and timbered or square-set
stoping methods for cases where the ore is weak and the
surrounding rock is so weak that temporary timbered support
is necessary as an interim measure prior to filling with
broken waste rock.
2. Input Materials - Nitroglycerine explosives (dynamite). About
0.5 kg/metric ton (1 lb/short ton) of ore mined.
3. Operating Parameters -
Temperature: Ambient
Pressure: Atmospheric
4. Utilities -
Electric Energy: Amount used varies widely dependong upon
method of mining and type of ore body. Mean value estimated to
be about 0.32 x 10a joules/metric ton (9 kWhe/metric ton or
0.086 x 106 Btu/short ton) .of ore.
108
-------
5. Waste Streams -
Mine water effluent
Storage of solid gangue
6. EPA Source Classification Code - None
7. References -
(1) U. S. Census of Mineral Industries, Major Group 10(Copper,
lead, zinc, gold, and silver ores) Table 3A, p 10B-11;
Table 7, pp 10-22.
(2) Private communication with members of the BCL staff who
have consulted with producers on energy requirements and
specifics of operation.
(3) Ageton, R. W., Chapter on Gold, Mineral Facts and Problems,
1970; Bureau of Mines, U. S. Department of the Interior,
Washington, D.C., pp 563-572.
(4) Ryan, J. Patrick; Chapter on Gold. Mineral Facts and
Problems, 1965, Bureau of Mines Bulletin 630, Bureau
of Mines, U. S. Department of the Interior, Washington,
D.C., pp 387-397.
(5) Development Document for Effluent Guidelines and Standards
of Performance, Ore Mining and Dressing Industry (Draft),
U. S. Environmental Protection Agency, Washington, D.C.
(Prepared by the Calspan Corp., Buffalo, N. Y.).
109
-------
GOLD - LODE DEPOSITS PROCESS NO. 7
Open-Pit Mining
1. Function - Open-pit mining involves the removal of ore from
deposits at or near the surface by a cycle of operations
consisting of drilling blast holes, blasting the ore, loading the
broken ore onto trucks or rail cars, and transporting it to the
concentrators. (In a few cases, blasting is not required; ore
is "ripped" by bulldozers and loaded.) Barren surface rock over-
laying the deposit must be removed to uncover the ore body; such
overburden may be up to (and, in one case, even exceeding) 152
meters (500 feet) thick.
2. Input Materials - Explosives (ammonium nitrate-fuel oil) 0.55 kg/
metric ton (1.1/short ton) of material mined.
3. Operating Parameters -
Temperature: Ambient
Pressure: Atmospheric
4. Utilities -
Diesel Fuel: 63 liters/metric ton (15.0 gal/short ton.) of ore
Equivalent Energy: 2.2 x 10s joules/metric ton (206 x 103 Btu/
short ton) of ore.
5. Waste Streams -
Airborne particulates from blasting
No water runoff in the only open-pit gold mine in the U.S.
(Nevada, desert climate)
Stockpiling of overburden
6. EPA Source Classification Code - None
7. References - .
(1) Private communication with members of the BCL staff who have
consulted with producers on energy requirements and specifics
of operation.
110
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(2) Ageton, R. W., Chapter on Gold, Mineral Facts and Problems,
1970; Bureau of Mines, U. S. Department of the Interior,
Washington, D.C., pp 563-572.
(3) Ryan, J. Patrick; Chapter on Gold, Mineral Facts and Prob-
lems, 1965, Bureau of Mines Bulletin 630, Bureau of Mines,
U. S. Department of the Interior, Washington, D.C.,
pp 387-397.
(4) Development Document for Effluent Guidelines and Standards
of Performance, Ore Mining and Dressing Industry (Draft),
U. S. Denvironmental Protection Agency, Washington, D.C.
(Prepared by the Calspan Corp., Buffalo, N. Y.).
Ill
-------
GOLD - HIGH GRADE LODE ORE PROCESS NO. 8
Crushing, Grinding, and Classifying
1. Function - If ore is to be concentrated by flotation or gravity
separation, it'must be ground to a fineness sufficient to liberate
the valuable minerals from the associated gangue. To accomplish
this, it is usually crushed at the mine site to an intermediate
size for subsequent handling in the grinding operation at the
mill. Grinding is done in ball mills or rod mills with a
classifier in the circuit to separate and return ground over-
size ore to the grinding mills.
2. Input Materials - Ore and water to the grinding mills and
classifiers
3. Operating Parameters - Crushing is a separate operation, usually
done dry. Grinding is usually done wet in a closed circuit with
a classifier.
Temperature: Ambient
Pressure: Atmospheric
4. Utilities -
o
Crushing: 0.11 x 10 joules/metric ton (3.1 kWhe/metric ton or
0.029 x 10° Btu/short ton) of ore
Grinding and Classifying: 0.56 x 10° joules/metric ton (15.4
kWhe/metric ton or 0.15 x 10° Btu/short ton) of ore
5. Haste Streams -
Dust, particulates from the crushing operation
Water, effluents from grinding
Waste rock (associated with crushing operation at mine shaft)
6. EPA Source Classification Code - None
112
-------
7. References -
(1) Private communication with members of the BCL staff who
have consulted with producers on energy requirements and
specifics of operation.
(2) Ageton, R. W.,- Chapter on Gold, Mineral Facts and Problems,
1970, Bureau of Mines, U. S. Department of the Interior,
Washington, D.C., pp 563-572.
(3) Ryan, J. Patrick; Chapter on Gold. Mineral Facts and Prob-
lems, 1965, Bureau of Mines Bulletin 630, Bureau of Mines,
U. S. Department of the Interior, Washington, D.C., pp 387-
397.
(4) Development Document for Effluent Guidelines and Standards
of Performance, Ore Mining and Dressing Industry (Draft),
U. S. Evnrionmental Protection Agency, Washington, D.C.
(Prepared by the Calspan Corp., Buffalo, N. Y.).
113
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GOLD - HIGH-GRADE LODE ORE
PROCESS NO. 9
Flotation
1.
2.
3.
4.
6.
7.
Function - The flotation technique may be used to separate ground
ore mineral particles from gangue mineral particles and from each
other in complex ores if the differences in the surface charac-
teristics between the various ore mineral and gangue particles
are sufficiently large. In the flotation process, the ground
ore is agitated by rising air bubbles in cells containing water,
various oils, and chemical reagents which cause the mineral
particle to be selectively wetted by the oil present and become
attached to the rising air bubbles, whereupon they rise to the
surface of the cell and are scraped off. In complex ores
containing more than one ore mineral value, reagents called
depressants are used to "depress" one type mineral particle
while the other is being floated.
Input Materials - Ground ore, water, oils, inorganic, and
organic flotation reagents.
Operating Parameters - Flotation cells are operated at ambient
temperature and pressure.
Utilities -
Electric Energy: 0.24 x 10^ joules/metric ton (6.6 kWhe/metric
ton or 0.063 x 106 Btu/short ton) ground ore input
Waste Streams -
Slurries containing tailings, reagent losses to tailings
•
Solid tailings remaining after dewatering
EPA Source Classification Code - None
References -
(1) Private communication with members of the BCL staff who
have consulted with producers on energy requirements and
specifics of operation.
114
-------
(2) Ageton, R. W., Chapter on Gold, Mineral Facts and
Problems, 1970, Bureau of Mines, U. S. Department of
the Interior, Washington, D.C., pp 563-572.
(3) Ryan, J. Patrick, Chapter on Gold, Mineral Facts and
Problems, 1965, Bureau of Mines Bulletin 630, Bureau of
Mines, U. S. Department of the Interior, Washington,
D.C., pp 387-397.
(4) Development Document for Effluent Guidelines and Standards
of~Perfonnance, Ore Mining and Dressing Industry (Draft),
U. S. Environmental Protection Agency, Washington, D.C.
(Prepared by the Calspan Corp., Buffalo, N. Y.).
115
-------
GOLD - LODE DEPOSITS PROCESS NO. 3
Gravity Separation
1. Function - Gold, with its high density, is easily separated from
the lighter weight gangue by gravity concentration. Accordingly,
practice on lode ores containing sulfides of lead, zinc, and
copper, in addition to native gold (and silver) is to make a
prior gravity separation of native gold (and silver) in the ground
ore by jigging (gold in finely ground ore also can be gravity-
concentrated by tabling). Gold, separated in this manner, can
be recovered by amalgamation, or alternatively, by cyanidation
methods. After the precious metals are recovered, the jig
concentrate is sent to a flotation circuit for the separation
of other metal sulfide mineral particles.
2. Input Materials - Ground ore from the grinding circuits
3. Operating Parameters -
Temperature: Ambient
Pressure: Atmospheric
4. Utilities -
Electric Energy: (Jigs or tables) Very low on a per-ton-of-ore
basis
5. Waste Streams -
Slurried ore solids
Mercury contaminants from losses in the amalgamation circuit
Heavy metals and cyanide dissolved in tailing pond effluent in
plants using cyanidation recovery processes, cyanide could also
accidentally be lost in an accidental discharge from the flotation
machines
6. EPA Source Classification Code - None
116
-------
7. References -
(1) Private communication with members of the BCL staff who
have consulted with producers on energy requirements and
specifics of operation.
(2) Ageton, R. W., Chapter on Gold, Mineral Facts and Problems,
1970, Bureau of Mines, U. S. Department of the Interior,
Washington, D.C., pp 563-572.
(3) Ryan, J. Patrick; Chapter on Gold, Mineral Facts and Prob-
lems, 1965, Bureau of Mines Bulletin 630, Bureau of Mines,
U. S. Department of the Interior, Washington, D.C., 387-397.
(4) Development Document for Effluent Guidelines and Standards
of Performance, Ore Mining and Dressing Industry (Draft),
U. S. Environmental Protection Agency, Washington, D.C.
(Prepared by the Calspan Corp., Buffalo, N. Y.).
117
-------
GOLD - LODE DEPOSITS PROCESS NO. 4
Grinding and Amalgamation
1. Function - Current practice (in the single mill in Colorado which
uses an amalgamation process) involves crushing and grinding of
lode ore separation of the gold-bearing black sands by jigging,
and final concentration of the gold in the sands by batch
amalgamation in a barrel amalgamator. In barrel amalgamation,
the ore is gently ground in a cylindrical rod or ball mill for
several hours to bring the gold and mercury into intimate contact.
The resulting amalgam is collected in a gravity trap.
2. Input Materials - Ground ore from a gold bearing lode deposit.
3. Operating Parameters -
Temperature: Ambient
Pressure: Atmospheric
4. Utilities -
Electric Energy: 0.56 x 108 joules/metric ton (15 kWhe/metric
ton or 0.15 x 106 Btu/short ton) of ore
5. Waste Streams -
Water containing suspended solids from amalgamation plant to
tailing pond (copper, iron, mercury, and zinc in solution)
6. EPA Source Classification Code - None
7. References -
(1) Private communication with members of the BCL staff who have
consulted with producers on energy requirements and specifics
of operation.
(2) Ageton, R. W., Chapter on Gold, Mineral Facts and Problems,
1970, Bureau of Mines, U. S. Department of the Interior,
Washington, D.C., pp 563-572.
118
-------
(3) Ryan, J. Patrick, Chapter on Gold, Mineral Facts and Prob-
lems, 1965, Bureau of Mines Bulletin 630, Bureau of Mines,
U. S. Department of the Interior, Washington, D.C., pp 387-
397.
(4) Development Document for Effluent Guidelines and Standards
of Performance, Ore Mining and Dressing Industry (Draft),
U. S. Environmental Protection Agency, Washington, D.C.
(Prepared by the Calspan Corp., Buffalo, N. Y.).
119
-------
GOLD - LODE DEPOSITS PROCESS NO. 5
Retorting
1. Function - Gold dissolved in mercury is recovered by distilling
off the mercury in a retort.
2. Input Materials - Gold amalgam
3. Operating Parameters -
The retort is heated to vaporize the mercury constituent [b.p.
357 C (675 F)]. The pressure is atmospheric.
4. Utilities -
The heat required is relatively low since only small amounts of
gold and mercury are handled relative to the amount of ore mined.
5. Waste Streams -
Mercury emissions
6. EPA Source Classification Code - None
7. References -
(1) Private communication with members of the BCL staff who
have consulted with producers on energy requirements and
specifics of operation.
(2) Ageton, R. W., Chapter on Gold, Mineral Facts and Prob-
lems, 1970, Bureau of Mines, U. S. Department of the
Interior, Washington, D.C., pp 563-572.
(3) Ryan, J. Patrick, Chapter on Gold, Mineral Facts and Prob-
lems, 1965, Bureau of Mines Bulletin 630, Bureau of Mines,
U. S. Department of the Interior, Washington, D.C., pp 387-
397.
(4) Development Document for Effluent Guidelines and Standards
of Performance, Ore Mining and Dressing Industry (Draft),
U. S. Environmental Protection Agency, Washington, D.C.
(Prepared by the Calspan Corp., Buffalo, N. Y.).
120
-------
GOLD - LODE DEPOSITS PROCESS NO. 10
Cyanide Leaching
1. Function - Cyanidation leaching of gold ore is done by four meth-
ods in the United States. For low-grade ores, and for recovery
of old mine waste dumps, heap leaching is used. For high-grade
ores, vat leaching, agitation leaching, and carbon-cyanidation are
used (in the carbon-cyanidation process, the solubilized gold
cyanide is first collected by adsorption onto activated charcoal
and then stripped with hot caustic).
2. Input Materials - Low-grade ore (old mine dumps) in the case of
heap leaching; higher grade ground ore in the case of vat, agita-
tion and charcoal-cyanidation leaching, cyanide, and water.
3. Operating Parameters -
Usually at ambient temperature and pressure.
4. Utilities -
Electric Energy: Pumping, 0.12 x 108 joules/metric ton (3.3 kWhe/
metric ton or 0.032 x 10° Btu/short ton) of ore
Diesel Fuel Oil: For ore transfer, 1.8 liters/metric ton (0.48
gal/short ton) of ore
5. Waste Streams -
Waste water from heap leaching containing large amounts of
suspended solids. It also may contain mercury or cyanide.
Waste water from other types of leaching of ground ore have
high dissolved heavy metal concentrations, a high concentration
of suspended solids, and dissolved reagents lost in the mill
beneficiation processes. Cyanide and mercury are the most
prominent.
Solid wastes remaining after leaching
6. EPA Source Classification Code - None
121
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7. References -
(1) Private communication with members of the BCL staff who
have consulted with producers on energy requirements
and specifics of operation.
(2) Ageton, R. W., Chapter on Gold, Mineral Facts and Prob-
lems, 1970, Bureau of Mines, U. S. Department of the
Interior, Washington, D.C., pp 563-572.
(3) Ryan, J. Patrick, Chapter on Gold, Mineral Facts and Prob-
lems, 1965, Bureau of Mines Bulletin 630, Bureau of Mines,
U. S. Department of the Interior, Washington, D.C., pp 387-
397.
(4) Development Document for Effluent Guidelines and Standards
of~Performance, Ore Mining and Dressing Industry (Draft),
U. S. Environmental Protection Agency, Washington, D.C.
(Prepared by the Calspan Corp., Buffalo, N. Y.).
122
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GOLD - LODE ORE PROCESS NO. 11
Filtering
1. Function - Leaching dissolves gold as a cyanide compound in the
dilute cyanide solution. After the leaching step is completed,
the cyanide pulp is washed and decanted in a series of thicken-
ers, and the supernatent solution from the thickeners is clari-
fied by pressure filtering, after which the dissolved gold is
extracted either by zinc precipitation, or absorption of the
solubilized gold cyanide on activated carbon, followed by
stripping with hot caustic. Only a small volume of hot caustic
is necessary to strip the gold from the charcoal.
2. Input Materials - Gold-bearing cyanide solutions, wash water,
zinc and caustic
3. Operating Parameters -
Temperature: Ambient
Pressure: As high as 34 kg (75 Ib) are used in pressure filters
for classifying solutions
4. Utilities -
Electric Energy: 0.01 x 108 joules/metric ton (0.28 kWhe/
metric ton or 0.003 x 10^ Btu/short ton) of treated ore
5. Waste Streams -
The solution passes onto the precipitation step. Water required
to wash and remove filter cake.
Solid filter cake entrained in the filtering medium (removed by
washing)
6. EPA Source Classification Code - None
7. References -
(1) Private communication with members of the BCL staff who
have consulted with producers on energy requirements and
specifics of operation.
123
-------
(2) Ageton, R. W., Chapter on Gold, Mineral Facts and Prob-
lems, 1970, Bureau of Mines, U. S. Department of the
Interior, Washington, D.C., pp 563-572.
(3) Ryan, J. Patrick, Chapter on Gold, Mineral Facts and
Problems, 1965, Bureau of Mines Bulletin 630, Bureau of
Mines, U. S. Department of the Interior, Washington, D.C.,
pp 387-397.
(4) Development Document for Effluent Guidelines and Standards
of Performance, Ore Mining and Dressing Industry (Draft),
U. S. Environmental Protection Agency, Washington, D.C.
(Prepared by the Calspan Corp., Buffalo, N. Y.).
124
-------
GOLD - LODE DEPOSITS PROCESS NO. 12
Carbon Extraction
1- Function - This process, as currently used in the United States,
treats only the slimes in the overflow from a cyclone classi-
fier in the grinding circuit (the coarser underflow is vat leached
and precipitated with zinc). Slimes in the overflow are mixed
with cyanide solution in large tanks and agitated. It is then
passed through a series of vats where the solubilized gold
cyanide is collected by adsorption on activated charcoal held
on screens. Gold is stripped from the charcoal with small
amounts of hot caustic.
2. Input Materials - Overflow from the cyclone classifier
3. Operating Parameters - Hot caustic solutions are used to
desorb the loaded carbon.
4. Utilities -
Electric Energy: Pumping, (usage estimated to be about the same
as for classification and precipitation with zinc) - 0.01 x 10^
joules/metric ton (0.28 kWhe/metric ton or 0.003 x 106 Btu/short
ton) of ore treated.
5. Haste Streams -
Cyanide solution is recycled, hence the amount present in
effluent is reduced.
Slurried ore solids in tailing ponds
6. EPA Source Classification Code - None
7. References -
(1) Private communication with members of the BCL staff who
have consulted with producers on energy requirements and
specifics of operation.
(2) Ageton, R. W., Chapter on Gold, Mineral Facts and Prob-
lems, 1970, Bureau of Mines, U. S. Department of the
Interior, Washington, D.C., pp 563-572.
125
-------
(3) Ryan, J. Patrick, Chapter on Gold, Mineral Facts and Prob-
lems, 1965, Bureau of Mines Bulletin 630, Bureau of Mines,
U. S. Department of the Interior, Washington, D.C., pp 387-
397.
(4) Development Document for Effluent Guidelines and Standards
of Performance, Ore Mining and Dressing Industry (Draft),
U. S. Environmental Protection Agency, Washington, D.C.
(Prepared by the Calspan Corp., Buffalo, N. Y.).
126
-------
GOLD - LODE DEPOSITS PROCESS NO. 13
Zinc Precipitation, Filtration
1. Function - Gold is precipitated from pregnant cyanide leach
solutions with zinc dust. The precipitate is collected in a
filter press and the spent cyanide filtrate is recycled (with
additions.of cyanide to bring it up to leaching strength).
2. Input Materials - Pregnant leach solution and zinc dust.
3. Operating Parameters -
Temperature: Ambient
Pressure: Atmospheric
4. Uti1ities -
Electric Energy: Pumping, (estimated from analogous pumping costs
from pressure filtering) - 0.01 x 10° joules/metric ton (0.28
kWhe/metric ton or 0.003 x 106 Btu/short ton) of ore
5. Haste Streams -
Filtrate is recycled, losses only
Gold precipitate is valuable, losses are therefore small.
6. EPA Source Classification Code - None
7. References -
(1) Private communication with members of the BCL staff who
have consulted with producers on energy requirements and
specifics of operation.
(2) Ageton, R. W., Chapter on Gold, Mineral Facts and Problems,
1970, Bureau of Mines, U. S. Department of the Interior,
Washington, D.C., pp 563-572.
127
-------
(3) Ryan,-J. Patrick, Chapter on Gold. Mineral Facts and Prob-
lems, 1965, Bureau of Mines Bulletin 630, Bureau of Mines,
U. S. Department of the Interior, Washington, D.C., pp 387-
397.
(4) Development Document for Effluent Guidelines and Standards
of Performance, Ore Mining and Dressing Industry (Draft),
U. S. Environmental Protection Agency, Washington, D.C.
(Prepared by the Calspan Corp., Buffalo, N. Y.).
128
-------
Iron
The iron ore industry of the United States grew from an annual out-
put of less than 5 million tons in 1870 to over 115 million tons
annually in 1951. Since that time, production has declined to about
90 million tons a year, of which about 83 percent is from the Lake
Superior region. Approximately 40 million tons of ore per year are
imported—that is, about one-third of the total amount consumed.
The Lake Superior district is the big production center for iron ore,
producing about 83 percent of all crude ore mined. The remaining
production was from 17 other States, of which the principal pro-
ducers were California, Missouri, Wyoming, Utah, New York and Penn-
sylvania. Open pit mines produce approximately 90 percent of the
iron ore in the United States.
The iron ore deposits of the United States may be classified on the
basis of their mineral content and rock type for the purposes of
this report. Accordingly, eight categories are identified which
characterize domestic deposits. These are:
Magnetite iron ore deposit
Magnetite-hematite iron ore deposit
Hematite iron ore deposit
d) Hematite-limonite iron ore deposit
(e) Limonite and siderite iron ore deposits
(f) Taconite iron ore deposit
(g) Jaspilite Iron ore deposit
(h) Pyrites iron ore deposit
(i) Manganiferous iron ore deposit.
Most of the iron ores currently recovered are beneficiated to an
iron ore concentrate and most of the concentrates are pelletized
prior to shipment. Today, sintering is used almost entirely in
connection with iron ore smelting and is usually accomplished within
a relatively short distance of the smelting operation. Briquetting
and nodulizing are infrequently used methods of agglomerating iron
ores resulting in briquettes and nodules, respectively. In summary,
the products that can be shipped from the iron mines are:
Run-of-mine ore
Direct shipping ore
Iron ore concentrate
d) Manganiferous iron ore concentrate
e) Pellets
f) Briquettes
Nodules
Sinter (cake).
129
-------
co
o
V AtmosplMfic Emission*
9 Liquid W»U
~a Solid WBM
-------
IRON - ALL TYPES OF DEPOSITS PROCESS NO, 1
Open Pit Mining
1. Function - Open pit mining involves the removal of ore from
deposits at or near the surface by a cycle of operations consisting
of drilling blast holes, blasting the ore, loading the broken
ore onto trucks, skips, or rail cars, and transporting it to the con-
centrators. (In a few cases, blasting is not required; ore is
"ripped" by bulldozers and loaded.) Barren surface rock overlaying
the deposit must be removed-to uncover the ore body.
2. Input materials - Explosives (ammonium-nitrate-fuel oil) 0.35 kg/
metric ton (0.7 Ib/short ton) of ore
3. Operating Parameters -
Temperature: Ambient
Pressure: Atmospheric
4. Utilities -
Electrical Energy: 0.90 x 108 joules/metric ton (27.5 kWhe/
metric ton or 0.26 x 10° Btu/short ton) of ore
Diesel Fuel: 0.71 liters/metric ton (0.17 gal/short ton) of
ore
5.. Waste Streams -
Airborne particulates from blasting and loading
Waste water from the mine containing suspended solids and dissolved
materials, oil, and grease
Storage of overburden and runoff from it
6. EPA Source Classification Code - None
7. References -
(1) Private communication with BCL staff who have visited producers.
(2) Development Document for Effluent Guidelines and Standards of
Performance, Ore Mining and Dressing Industry (Draft), U. S.
Environmental Protection Agency, Washington, D.C. (prepared
by the Calspan Corp., Buffalo, N. Y.), April 1975.
131
-------
(3) Reno, Horace T., Chapter on Iron, Mineral Facts and
Problems, 1965, Bureau of Mines Bulletin 630, Bureau
of Mines, U.S. Department of the Interior, Washington,
D.C., pp 455-479.
(4) Reno, Horace T., and Brantley, Francis E., Chapter on
Irg_n_, Mineral Facts and Problems, 1970, Bureau of Mines
Bulletin 650, Bureau of Mines, U.S. Department of the
Interior, Washington, D.C., pp 291-i314.
(5) U.S. Steel Corp., (MacGannon, Harold E., Editor) The
Making, Shaping, and Treating of Steel. 9th Ed., 1971,
U.S. Steel Corp., Pittsburgh, PA, 1420 pp.
132
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IRON - ALL TYPES OF DEPOSITS PROCESS NO. 2
Underground Mining
1. Function - Underground methods are used to extract iron
ore only where the cost of stripping is too high for
economical open pit mining. The technique consists of
sinking vertical shafts adjacent to the deposits far enough
removed to avoid the effects of surface subsidence resulting
from mining operations.
Sub!eve! caving has been the principal underground method
of mining iron ore in the Lake Superior district. Block
and panel caving and variations thereof are used in large
ore bodies where dilution is not a problem. Shrinkage
stoping, open stoping, sublevel stoping,'with many modifica-
tions and various other methods also are used depending on
the size, shape, and character of the orebody, and the
character of the enclosing rocks. Most bedded deposits are
mined by room and pillar methods similar to those used in
coal mining.
2. Input Materials - Explosives, ammonium nitrate and fuel
oil, ammonium nitrate-TNT slurries, and gelatin dynamites
are used.
3. Operating Parameters -
Temperature: Ambient
Pressure: Atmospheric
4. Utilities (Based on usage in a Michigan underground iron mine) •
Electrical Energy: 1.3 x 108 joules/metric ton (37 kWhe/metric
ton or 0.35 x 10° Btu/short ton of ore
Natural Gas: (0.8 steres, 28 cu ft): 0.87 cu meters/metric
ton (28 cu ft/short ton) of ore
Diesel Fuel: (0.18 liters, 0.045 gal): 0.19 liters/metric ton
(0.045 gal/short ton) of ore
Gasoline: (0.03 liters, 0.008 gal): 0.033 liter/metric ton
(0.008 gal/short ton) of ore
133
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5. Waste Streams -
Waste water from the mine containing suspended solids,
dissolved material, oil, and grease
Storage of waste rock from shafts and cuts to the ore body
6. EPA Source Classification Code - None
7. References -
(1) Private communication with BCL staff who have visited
producers.
(2) Development Document for Effluent Guidelines and Standards
of Performance, Ore Mining and Dressing Industry (Draft),
U. S. Environmental Protection Agency, Washington, D.C.
(prepared by the Calspan Corp., Buffalo, N. Y.), April 1975.
(3) Reno, Horace T., Chapter on Iron, Mineral Facts and
Problems, 1965, Bureau of Mines Bulletin 630, Bureau
of Mines, U. S. Department of the Interior, Washington,
D.C., pp 455-479.
(4) Reno, Horace T., and Brantley, Francis E., Chapter on
Iron, Mineral Facts and Problems, 1970, Bureau of Mines
Bulletin 650, Bureau of Mines, U. S. Department of the
Interior, Washington, D.C., pp 291-314.
(5) U.S. Steel Corp. (MacGannon, Harold E., Editor) The
Making. Shaping, and Treating of Steel. 9th Ed., 1971,
U.S. Steel Corp., Pittsburgh, PA, 1420 pp.
134
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IRON - DIRECT SHIPPING GRADES OF IRON ORE PROCESS NO. 3
Crushing. Washing, and Screening
1. Function - Direct shipping ore requires only crushing, screen-
ing, and washing (to remove fine clay and sand) prior to ship-
ment to the steel mills. High-grade, hard lump ore is crushed
to about 20 cm (8 inches) if destined for use in an open-
hearth furnace and a maximum of 10 cm (4 inches) if destined
for use in a blast furnace. Practice is to remove minus 0.64
cm (1/4-inch) material. Minus 0.64 cm (1/4-inch) material
either is sold at a discount or agglomerated.
2. Input Materials - Iron ore from the mine and water
3. Operating Parameters -
Temperature: Ambient
Pressure: Atmospheric
4. Utilities -
Electrical Energy: for crushing, 0.51 x 108 joules/metric ton
(14.1 kWhe/metric ton or 0.13 x 106 Btu/short ton) or ore;
for pumpnng, 0.19 x 10° joules/metric ton (5.3 kWhe/metric
ton or 0.050 x 106 Btu/short ton) of ore
5. Waste Streams -
Dissolved and suspended solids in wash water which is clarified.
Water is then recycled. Some losses.
«
6. EPA Source Classification Code - None
7. References -
(1) Private communication with BCL staff who have visited
producers.
(2) Development Document for Effluent Guidelines and Standards
of Performance, Ore Mining and Dressing Industry (Draft),
U. S. Environmental Protection Agency, Washington, D.C.
(prepared by the Calspan Corp., Buffalo, N. Y.), April 1975.
135
-------
(3) Reno, Horace T., Chapter on Iron, Mineral Facts and
Problems, 1965, Bureau of Mines Bulletin 630, Bureau
of Mines, U. S. Department of the Interior, Washington,
D.C., pp 455-479.
(4) Reno, Horace T., and Brant!ey, Francis E., Chapter on
Iron, Mineral Facts and Problems, 1970, Bureau of Mines
Bulletin 650, Bureau of Mines, U. S. Department of the
Interior, Washington, D.C., pp 291-314.
(5) U.S. Steel Corp. (MacGannon, Harold E., Editor) The
Making, Shaping, and Treating of Steel, 9th Ed., 1971,
U.S. Steel Corp., Pittsburgh, PA, 1420 pp.
136
-------
IRON - SIZED IRON ORE PROCESS NO. 4
Crushing, Grinding, and Classifying
1. Function - The lower grade taconite and jaspilite ores from
the Lake Superior District must be ground fine to free the
iron oxide minerals from the associated gangue. Accordingly,
these ores are crushed and ground with a classifier in the
grinding circuit to remove-fine clay and sands.
2. Input Materials - Mined iron ore and water.
3. Operating Parameters -
Temperature: Ambient
Pressure: Atmospheric
4. Utilities -
Electrical Energy: for crushing, 0.51 x 108 joules/metric ton
(14.1 kWhe/metric ton or 0.13 x 106 Btu/short ton) of ore;
for grinding, 2.0 x 108 joules/metric ton (54.7 kWhe/
metric ton or 0.52 x 10& Btu/short ton) of ore; for pump-
ing, 0.19 x 108 joules/metric ton (5.3 kWhe/metric ton or
0.050 x 106 Btu/short ton) of ore
5. Haste Streams -
Water and ore are recycled but there are some losses.
6. EPA Source Classification Code - None
7! References -
(1) Private communication with BCL staff who have visited
producers.
(2) Development Document for Effluent Guidelines and Standards
of Performance, Ore Mining and Dressing Industry (Draft),
U. S. Environmental Protection Agency, Washington, D.C.
(prepared by the Calspan Corp., Buffalo, N. Y.), April 1975.
(3) Reno, Horact T., Chapter on Iron, Mineral Facts and
Problems, 1965, Bureau of Mines Bulletin 630, Bureau of
Mines, U.S. Department of the Interior, Washington, D.C.,
pp 455-479.
137
-------
(4) Reno, Horace T., and Brantley, Francis E., Chapter on Iron,
Mineral Facts and Problems, 1970, Bureau of Mines Bulletin
650, Bureau of Mines, U. S. Department of the Interior,
Washington, D.C., pp 291-314.
(5) U.S. Steel Corp. (MacGannon, Harold E., Editor) The
Making, Shaping, and Treating of Steel, 9th Ed., 1971,
U.S. Steel Corp., Pittsburgh, PA, 1420 pp.
138
-------
IRON - IRON ORE REQUIRING CONCENTRATION PROCESS NO. 5
Gravity Concentration
1. Function - Gravity concentration of iron ore involves jigging,
heavy medium separation, Humphrey spirals, and hydrocyclones.
Jigging is applied to coarse crushed ores, usually plus 1/4
inch. Heavy medium separators make a more rapid and precise
separation on unsized ore than do jigs. Both Humphrey
spirals and hydrocyclones may be operated with or without
suspension medium. Humphrey spirals operate on ground ore
by a combination of sluicing and centrifugal action. Hydro-
cyclones separate the heavier and coarser fractions of ground
ore at the apex of a long cone, while lighter and finer
particles overflow from the central vortex. Humphrey spirals
make a better separation of fine materials than do hydrocy-
clones, but do not have as high capacity. Heavy-medium hydro-
cyclones appear to be the most favored method of gravity
separation by the large producers.
2. Input Materials - Crushed or ground, classified iron ore,
water, and heavy media.
3. Operating Parameters -
Temperature: Ambient
Pressure: Atmospheric
4. Utilities (Electrical Energy) -
The amount of energy used depends on the type of processing.
The following is typical of electrical energy usage in an iron
ore concentration plant: for concentration, 0.19 x 10°
joules/metric ton (5.3 kWhe/metric ton or 0.050 x 10° Btu/
short ton) of ore; water handling, 0.19 x lO0* joules/metric
ton (5.3 kWhe/metric ton or 0.050 x 10° Btu/short ton) of ore;
tailings disposal, 0.15 x 10^ joules/metric ton (4.2 kWhe/
metric ton or 0.040 x 10° Btu/short ton) of ore
5. Waste Materials -
Tailings (10 to 15 percent solid loadings). In some areas,
for example, Silver Bay, Minnesota, and the Grovel and Mine in
Dickenson County, Michigan, amphibole minerals with fibrous
characteristics are a constituent part of the tailings. These
asbestic minerals release measureable quantities of asbestos
fibers in the waste water.
139
-------
Spills, including water.
6. EPA Source Classification Code - None
7. References -
(1) Private communication with BCL staff who have visited
producers.
(2) Development Document for Effluent Guidelines and Standards^
of Performance, Ore Mining and Dressing Industry (Draft),~
U. S. Environmental Protection Agency, Washington, D.C.
(prepared by Calspan Corp., Buffalo, N. Y.), April 1975.
(3) Reno, Horace T., Chapter on Iron, Mineral Facts and
Problems, 1965, Bureau of Mines Bulletin 630, Bureau of
Mines,-U. S. Department of the Interior, Washington, D.C.,
pp 455-479.
(4) Reno, Horace T., and Brantley, Francis E:, Chapter on Iron,
Mineral Facts and Problems, 1970, Bureau of Mines Bulletin
650, Bureau of Mines, U. S. Department of the Interior,
Washington, D.C., pp 291-314.
(5) U.S. Steel Corp. (MacGannon, Harold E., Editor) The
Making, Shaping, and Treating of Steel, 9th Ed., 1971,
U.S. Steel Corp., Pittsburgh, PA, 1420 pp.-
140
-------
IRON - IRON ORE REQUIRING CONCENTRATION PROCESS NO. 6
Flotation
1. Function - In the flotation process, the surfaces of ground
mineral particles, usually of the ore mineral, are selective-
ly conditioned with reagents so that they are aerophilic in a
water suspension. Thus they become selectively attached to
air bubbles and rise to the surface where they float in a
supernatent froth.and are collected. The gangue particles
are hydrophilic and remain behind. There are two types of
flotation processes, the anionic--which utilizes anionic
(negatively charged ion) collectors (the most common of which
are fatty acids), and cationic (positively charged ion) col-
lectors (amines). So far, only the anionic type has been
used commercially for iron ore, but cationic flotation has
been used to float silica and apatite away from iron minerals
on an experimental scale.
2. Input Materials - Ground ore, water (densifier thickness
Underflow), air, and flotation reagents.
3. Operating Parameters -
Temperature: Ambient
Pressure: Atmospheric
4. Utilities (Electrical Energy) -
Not known precisely, about 0.24 x 108 joules/metric ton (6.6
kWhe/metric ton or o.o63 x 10° Btu/short ton) of ore
5. Waste Streams -
To prevent buildup of soluble salts, 20 percent of the flota-
tion water is discharged after settling and treatment (alum).
Solid tailings after dewatering
6. EPA Source Classification Code - None
141
-------
7. References -
(1) Private communication with BCL staff who have visited
producers.
(2) Development Document for Effluent Guidelines and Standards
of Performance, Ore Mining and Dressing Industry (Draft),
U. S. Environmental Protection Agency, Washington, D.C.
(prepared by Calspan Corp., Buffalo, N. Y.), April 1975.
(3) Reno, Horace T., Chapter on Iron, Mineral Facts and
Problems, 1965, Bureau of Mines Bulletin 630, Bureau of
Mines, U. S. Department of the Interior, Washington, D.C.,
pp 455-479.
(4) Reno, Horace T., and Brantley, Francis E., Chapter on Iron,
Mineral Facts and Problems, 1970, Bureau of Mines Bulletin
650, Bureau of Mines, U. S. Department of the Interior,
Washington, D.C., pp 291-314.
(5) U.S. Steel Corp. (MacGannon, Harold E., Editor) The
Making, Shaping, and Treating of Steel, 9th Ed., 1971,
U.S. Steel Corp., Pittsburgh, PA, 1420 pp.
142
-------
IRON - IRON ORE REQUIRING CONCENTRATION PROCESS NO. 7
Magnetic Concentration
1. Function - Magnetic taconite ores are crushed and ground to
free the magnetite mineral and are usually concentrated in low
intensity wet magnetic separators. The concentration may be
performed in three stages in "rough", "intermediate", and
"finish" magnetic separators. Concentrate from the rough or
"cobber" separation is reground and magnetically separated in
a second, cleaner magnetic separator; the concentrates from
this second step are then sized in closed circuit in a hydro-
cyclone; oversize is recycled and undersize is concentrated
further (mechanically) in a hydroseparator; concentrates from
the hydroseparator are given a final treatment in a "finish"
magnetic separator.
Dry magnetic separation systems are not as widely applied as
wet systems. There are two types: low-intensity and high-
intensity magnetic separators. There is also a wet high-
intensity separator, but it has not been used commercially.
2. Input Materials - Ground ore
3. Operating Parameters -
Temperature: Ambient
Pressure: Atmospheric
4. Utilities -
Electrical energy for magnetic separation: about 0.040 x 10
joules/metric ton (1.1 kWhe/metric ton or 0.011 x 10° Btu/
short ton) of ore
5. Waste Streams -
Slurries of tailings to tailings basin from three magnetic
separations, and from the intermediate hydroseparation process
6. EPA Source Classification Code - None
143
-------
7. References -
(1) Private communication with BCL staff who have visited
producers.
(2) Development Document for Effluent Guidelines and Standards
oT Performance, Ore Mining and Dressing Industry (Draft)V
U. S. Environmental Protection Agency, Washington, D.C.
(prepared by Calspan Corp., Buffalo, N. Y.), April. 1975.
(3) Reno, Horace T., Chapter on Iron, Mineral Facts and
Problems, 1965, Bureau of Mines Bulletin 630, Bureau of
Mines, U. S. Department of the Interior, Washington, D.C.,
pp 455-479.
(4) Reno, Horace T., and Brantley, Francis E., Chapter on Iron,
Mineral Facts and Problems, 1970, Bureau of Mines Bulletin
650, Bureau of Mines, U. S. Department of the Interior,
Washington, D.C., pp 291-314.
(5) U.S. Steel Corp. (MacGannon, Harold E., Editor) The
Making, Shaping, and Treating of Steel, 9th Ed., 1971,
U.S. Steel Corp., Pittsburgh, PA, 1420 pp.
144
-------
IRON - IRON ORE REQUIRING CONCENTRATION PROCESS NO. 8
Pelletizing
1. Function - All minus 0.64 cm (1/4 inch) iron ores are agglom-
erated before reduction in the blast furnace. Pelletizing
involves the formation of pellets or balls from finely ground
iron ore. In a typical operation with finely ground magnetic
taconite ores, the concentrate from the finisher magnetic .
separation passes through a thickener and is filtered. The
filter cake is mixed with small amounts of bentonite and
measured amounts of water in a balling drum. The "green"
pellets from the balling drum are first dried, then bonded
by heating in an agglomeration furnace. There is also a
traveling grate system which is used for producing pellets.
2. Input Materials - Finely ground iron ore, water, and, usually,
bentonite [approximately 8 kg/metric ton (16 Ib/ton) of
pellets]
3. Operating Parameters -
Temperature: (1204-1371 C) (2200-2500 F)
Pressure: Atmospheric
4. Utilities -
Electrical Energy: 0.19 x 108 joules/metric ton (5.4 kWhe/
metric ton or 0.051 x 106 Btu/short ton) of pellets
Natural Gas: 8580 cu meters/metric ton (275,000 cu ft/short
ton) of pellets
Fuel Oil: 6.2 liters/metric ton (1.5 gal/short ton) of
pellets
5. Waste Streams -
Exhaust gases from the agglomeration furnace
Fine particles of minerals in thickener overflow (particularly
in cases where the thickener overflow is not recirculated)
Spills
6. EPA Source Classification Code - None
145
-------
7. References -
(1) Private communication with BCL staff who have visited
producers.
(2) Development Document for Effluent Guidelines and Standards
of"Performance, Ore Mining and Dressing Industry (Draft),
U. S. Environmental Protection Agency, Washington, D.C.
(prepared by Calspan Corp., Buffalo, N. Y.), April 1975.
_(3) Reno, Horace T., Chapter on Iron, Mineral Facts and
Problems, 1965, Bureau of Mines Bulletin 630, Bureau of
Mines, U. S. Department of the Interior, Washington, D.C.,
pp 455-479.
(4) Reno, Horace T., and Brantley, Francis E., Chapter on Iron,
Mineral Facts and Problems, 1970, Bureau of Mines Bulletin
650, Bureau of Mines, U. S. Department of the Interior,
Washington, D.C., pp 291-314.
(5) U.S. Steel Corp. (MacGannon, Harold E., Editor) The
Making, Shaping, and Treating of Steel, 9th Ed., 1971,
U.S. Steel Corp., Pittsburgh, PA, 1420 pp.
146
-------
IRON - IRON ORE REQUIRING CONCENTRATION PROCESS NO. 9
Sintering
1. Function - Sintering does not require as uniform a ground
input material as does pelletizing. It usually involves the
mixing of small amounts of coke and limestone with reclaimed
steel plant iron ore dusts (to make them self-fluxing). This
is followed by combustion to form a granular coarse self-
fluxing product for the blast furnace charge. Combustion of
the mixture takes place on a traveling grate provided with a
downdraft to promote combustion. After discharge from the
end of the traveling grate, the sinter is crushed, cooled,
and screened. Undersize is resintered.
2. Input Materials - Iron ore fines, blast furnace dust, sludge
containing metallics, mill scale, melt shop slag, blast
furnace oxygen dust, limestone or dolomite fines, and coke
fines
3. Operating Parameters -
Temperature: 1st Section, 1149 C (2100 F); Exit 816 C
(1500 F)
Pressure: Atmospheric
4. Utilities -
Fuel requirements not known precisely. U.S. Steel Corp.
operators report that the fuel requirement per ton of ore
for sintering is about double that of pelletizing.
5. Haste Streams -
Air Emissions
Iron ore dust consisting of Fe203 and F6304 with some
silica and limestone
Limestone dust, principally calcite
Coke dust
Combustion gases from ignition of coke oven gas and
natural gas fuels (with some use of fuel oil)
147
-------
Sinter dust—iron oxides, calcite iron-calcium silicate
and quartz
The major problem in the control of emissions from a sinter
reclamation plant is minimizing emissions from the wind box
of the sintering machines. There are 45 sinter reclamation
plants in the U.S. operating 72 sintering strands, 93 percent
of which are controlled with electrostatic precipitors, cy-
clones, or scrubbers.
The chemical composition of particulate emissions from three
plants having dust collecting systems are shown in the follow-
ing table:
Particulate
Component
Fe203
CaO
MgO
K20.
Si 02
A1203
Na20
ZnO
MnO
Chlorides
Sul fates
Hydrocarbons
Other
Loss on Ignition
Plant F
Weight
• Percent
33.9
7.1
5.3
5.2
4.8
2.6
1.6
0.4
0.2
8.5
7.5
7.4
1.6
13.9
Plant G
Weight
Percent
11.7
10.9
0.4
0.6
2.4
4.3
0.8
0.1
0.1
3.0
16.5
36.9
0.0
12.3
Plant H
Weight
Percent
28.0
15.0
2.0
8.1
4.6
2.5
0.0
0.0
0.0
8.8
2.1
0.0
0.0
28.9
Total
100.0
100.0
100.0
148
-------
Typical size distribution of participates from the wind box
exhausts on two sintering strands [each with a flow rate of
10,993 m3/min (385000 acfm) at 118 C (245 F)] controlled by
a multicyclone followed by an electrostatic precipitator is
as follows:
Particulate Size, Cumulative Weight Percent Retained
microns
>12.00
7.50
5.10
3.50
2.20
1.10
0.68
0.46
<0.46
Test No. 1
54.36
61.56
65.05
66.62
69.22
70.49
72.50
73.56
100.00
Test No. 2
10.43
21.50
30.97
40.20
47.89
58.65
66.99
76.48
100.00
Note: Particle size determinations were made with an
Andersen Cascade Impactor.
The gaseous emissions obtained from-this same test are as
follows:
Gaseous Component
Condensable hydrocarbons
Noncondensable hydrocarbons
Fluoride
Carbon monoxide
Sulfur dioxide
Sulfur tri oxide
Nitrogen oxides
Milligrams
NmJ
1.036
812.11
3.21
-
-
-
-
Grains
SCFD*
0.00453
0.3539
0.00140
-
-
-
-
ppm
-
230
-
8000
900
11.5
71.4
*Standard cubic foot (dry).
149
-------
The participate contents at the inlet and outlet sides of the
electrostatic precipitators at this plant during this test
were as follows:
mg/m3 (dry) grains/ft3 (dry)
Average ESP inlet 595 0.26
Average ESP outlet 69 0.03
This represents a collection efficiency of 88.4 percent. The
corresponding release of emissions to the atomosphere amount-
ed to 0.214 kg/metric ton (0.428 Ib/short ton) of sinter.
6. EPA Source Classification Code - None
7. References -
(1) Private communication with BCL staff who have visited
producers.
(2) Development Document for Effluent Guidelines and Standards
of Performance, Ore Mining and Dressing Industry (Draft),
U.S. Environmental Protection Agency, Washington, D.C.
(prepared by Calspan Corp., Buffalo, N.Y.), April 1975.
(3) Reno, Horace T., Chapter on Iron, Mineral Facts and
Problems, 1965, Bureau of Mines Bulletin 630, Bureau of
Mines, U.S. Department of the Interior, Washington, D.C.,
pp 455-479.
(4) Reno, Horace T., and Brantley, Francis E., Chapter on
Iron, Mineral Facts and Problems, 1970, Bureau of Mines
Bulletin 650, Bureau of Mines, U.S. Department of the
Interior, Washington, D.C., pp 219-314.
(5) U.S. Steel Corp. (MacGannon, Harold E., Editor) The
Making, Shaping, and Treating of Steel, 9th Ed., 1971,
U.S. Steel Corp., Pittsburgh, PA, 1420 pp.
(6) Control of Reclamation (Sinter) Plant Emissions Using
Electrostatic Precipitators. EPA-600/2-76-002, U.S.
Environmental Protection Agency, Washington, D.C. (pre-
pared by John Varga, Jr., Battelle Columbus Laboratories,
Columbus, Ohio) January 1976.
150
-------
IRON - IRON ORE REQUIRING CONCENTRATION PROCESS NO. 10
Briquetting
1. Function - Briquetting is a process by which iron ore fines
are mixed with a binder such as molasses and lime and formed
into briquettes in either mold presses or roll presses. In a
related process, hot briquetting, no binder is required; the
ore is heated, fed into a pressure-roll machine to produce
the briquettes. Neither process has been used commercially,
but cold briquetting is coming on stream on a very small
scale for agglomerating waste oxides (mill scale, blast
furnace dust, B.O.F. dust, etc.).
2. Input Materials - Ore fines, waste oxides, mill scale, dusts
from smelting operations
3. Operating Parameters
Temperature: Briquetting, Ambient;
Hot Briquetting, 871-1038 C (1600-1900 F)
Pressure: In hot briquetting, roll separating loads range
from 68 to 270 metric ton (75 to 300 short tons) for
roll diameters of 51 to 71 centimeters (20-28 inches)
and roll widths of 12 to 25 centimeters (4.7-10 inches).
4. Utilities -
Energy usage, not known precisely. U.S. Steel Corp. operators
report that hot briquetting requires about the same amount of
fuel per ton of ore as pelletizing.
5. Waste Streams -
Dust, particulates, particularly from hot briquetting
Dust, fumes from the pressure roll machine discharge
6. EPA Source Classification Code - None
7. References -
(1) Private communication with BCL staff who have visited
producers.
151
-------
(2) Development Document for Effluent Guidelines and Standards
of~Performance, Ore Mining and Dressing Industry (Draft),~
U. S. Environmental Protection Agency, Washington, D.C.
(prepared by Calspan Corp., Buffalo, N. Y.), April 1975.
(3) Reno, Horace T., Chapter on Iron, Mineral Facts and Problems,
1965, Bureau of Mines Bulletin 630, Bureau of Mines, U. S.
Department of the Interior, Washington, D.C., pp 455-479.
(4) Reno, Horace T., and Brantley, Francis E., Chapter on Iron,
Mineral Facts and Problems, 1970, Bureau of Mines Bulletin
650, Bureau of Mines, U. S. Department of the Interior,
Washington, D.C., pp 219-314.
(5) U.S. Steel Corp. (MacGannon, Harold E., Editor) The
Making, Shaping, and Treating of Steel, 9th Ed., 1971,
U.S. Steel Corp., Pittsburgh, PA, 1420 pp.
152
-------
IRON - IRON ORE REQUIRING CONCENTRATION PROCESS NO. 11
Nodulizing
1. Function - Nodulizing is another method of agglomerating iron ore
fines. Ore fines are heated in a rotary kiln to incipient fusion,
and are formed into balls by the rotary motion of the kiln. It
is not used to any great extent because the nodulized product is
not acceptable as blast furnace burden because it is non-uniform
in size and has inferior reducibility. Moreover, it has the dis-
advantage of high heat consumption. Nodules are acceptable for
open hearth use.
2. Input Materials - Ground iron ore
3. Operating Parameters -
Temperature: 1260-1371 C (2300-2500 F)
Pressure: Atmospheric
4. Utilities -
Natural gas (or equivalent): 62.4-125 cu meters/metric ton
(2000-4000 cu ft/short ton) of nodules
5. Waste Streams -
Exhaust gases from kiln
Dust, particulates in exhaust gases, and accompanying kiln discharge
6. EPA Source Classification Code - None
7. References -
(1) Private communication with BCL staff who have visited producers.
(2) Development Document for Effluent Guidelines and Standards
of Performance, Ore Mining and Dressing Industry (Draft).
U. S. Environmental Protection Agency, Washington, D.C.
(prepared by Calspan Corp., Buffalo, N. Y.), April 1975.
153
-------
(3) Reno, Horace T., Chapter on Iron, Mineral Facts and
Problems, 1965, Bureau of Mines Bulletin 630, Bureau of
Mines, U. S. Department of the Interior, Washington, D.C.,
pp 455-479.
(4) Reno, Horace T., and Brantley, Francis E., Chapter on Iron,
Mineral Facts and Problems, 1970, Bureau of Mines Bulletin
650, Bureau of Mines, U. S. Department of the Interior,
Washington, D.C., pp 291-314.
(5) U.S. Steel Corp. (MacGannon, Harold E., Editor) The
Making, Shaping, and Treating of Steel, 9th Ed., 1971,
U.S. Steel Corp., Pittsburgh, PA, 1420 pp.
154
-------
Lead and Zinc
Lead and zinc minerals occur in many major ore bodies in such
intimate mixtures that they must be mined together. At some
stage of processing, separations must be made. In addition,
lead and zinc ores commonly contain other metals, such as
copper, bismuth, antimony, gold, and silver, which for
technological or economical reasons must be separated from
lead and zinc. The processes for treating lead ores, zinc ores,
and lead-zinc ores are highly complicated operations interwoven
with each other as well as with processes for copper, precious
metals, cadmium, etc.
The total number of mine sources of zinc and lead in the United
States has been placed at about 300.
The United States is not self-sufficient in lead production from
domestic ores. Currently about 26 percent of consumption is
imported. Lead from primary production is only about half of
our consumption. Currently, our zinc production from primary
sources is only about one-third of domestic consumption.
For purposes of this report, the raw materials for the production
of lead and zinc are classified as follows:
a) Lead ores
b) Zinc ores
(c) Lead-zinc ores
(d) Copper-lead-zinc ores
(e) Complex ores containing lead and/or zinc
values.
The lead-zinc segment of the mining industry produces concentrates
of the ores being worked by processes to be described. The products
of the industry are:
(a) Lead concentrates
(b) Zinc concentrates, and
(c) Other metal concentrates depending on the
minerology of the ore body.
Almost all lead and zinc ores are mined by underground techniques
in contrast to the major open-pit operations of the copper industry.
Limited mining of lead and zinc by small open-pit operations
has been used in the Tri-state region of Missouri and in
Washington. Some zinc mines in the early stages of their
development are also mined by open-pit methods. Underground
methods most commonly used for lead and zinc mining include
block-caving, cut and fill, room and pillar, and various
stoping techniques.
155
-------
Ores of lead and zinc are concentrated using two general methods, gravity
and flotation. In gravity concentration, advantage is taken of the high
specific gravity of the lead minerals galena (specific gravity 7) and of
the zinc mineral sphalerite (specific gravity 4.7) to separate them from
the lighter gangue or nonore materials. Gravity separation is usually
done by float-sink methods in so-called heavy media. The flotation pro-
cess with lead and zinc ores is quite complex and exhibits many variations
depending on the type of ore, the association of minerals within the ore,
and the desired grade and recovery levels of lead or zinc concentrate
required. By the use of relatively small quantities of conditioning
chemicals, it is possible to manipulate the surface properties of the
different sulfide materials so that high-grade concentrates of lead and
zinc can be produced from even the most complex ores of lead, zinc,
copper, etc.
156
-------
en
To Smelting
Lead and Zinc
I Atmospheric Emissions
y Liquid Waste
—O Solid Waste
Recovery Alter
Further Processing
-------
LEAD AND ZINC - ALL TYPES OF MIXED LEAD-ZINC ORES PROCESS NO. 1
Underground Mining
1. Function - Lead and zinc ores are largely produced from underground
mines. The most common lead mineral mined is galena, lead sulfide,
which is often associated with the most common zinc sulfide mineral,
sphalerite, and with copper, silver, and gold. Other common zinc
minerals besides sphalerite include the oxide zincite, the sili-
cate zinc willemite, and a complex iron-zinc-manganese mineral,
franklinite. Sphalerite is often found in association with sul-
fides of lead and iron. Copper, gold, silver, and cadmium are
also found in association with sphalerite.
The largest producer of lead is the "New Lead Belt" of Southeast
Missouri. Ore bodies there which contain some zinc and copper
sulfides are large, horizontally-lying deposits which lend them-
selves to the room and pillar method of mining. Zinc and lead-zinc
deposits of the Tri-State, Upper Missippi Valley, Tennessee,
Virginia, and the Metaline (Washington) districts also tend to be
large, horizontal ore bodies, and open stopes with pillars (breast
stopes) are used exclusively in mining these ores. Zinc and lead-
zinc deposits in the western states do not have a self-supporting
overlying rock structure; accordingly, they are mined by artificially
supported stoping methods which include shrinkage stoping, cut and
fill stoping, and timbered stoping.
2. Input Materials - Explosives: 0.45 kg/metric ton (0.9 Ib/short
ton) of lead and zinc ore; Fuel oil: 1.67 liters/metric ton
(0.4 gal/short ton) of lead and zinc ore
3. Operating Parameters -
Temperature: Ambient
Pressure: Atmospheric
4. Utilities -
Q
Electrical energy: 1.8gx 10 joules/metric ton (51 kWhe/
metric ton or 0.48 x 10 Btu/short ton) of lead and zinc
ore
158
-------
5. Waste Streams -
Raw mine drainage containing suspended solids from blasting,
oils and greases. Because of the associated limestone or
dolomite, the water may be excessively alkaline.
Waste rock from shafts, cross-cuts, etc.
6. EPA Source Classification Code - None
7. References -
(1) Census of Mineral Industries (1967), U. S. Department of
Commerce, Major Group 10, Table 3A, p. 10B-11, and
Table 7, p. 10B-23.
(2) Private communication with BCL staff who have visited
producers.
(3) Rausch, Donald 0., and Mariacher, Burt C., Editors, AIME
World Symposium on the Mining and Metallurgy of Lead and
Zinc, 1970, Vol 1, Mining and Concentrating of Lead and
Zinc, 1017 pp.
(4) Paone, James, Chapter on Lead, Mineral Facts and Problems,
1970, Bureau of Mines Bulletin 650, Bureau of Mines, U. S.
Department of the Interior, Washington, D.C., pp 603-620.
(5) Heindl, R. A., Chapter on Zinc. Ibid., Ref. (4), pp 805-824.
(6) Development Document for Effluent Guidelines and Standards of
Performance, Ore Mining and Dressing Industry (Draft), U. S.
Environmental Protection Agency, Washington, D.C. (prepared
by Calspan Corp., Buffalo, N. Y.), April 1975. .
159
-------
LEAD AND ZINC - ALL TYPES OF MIXED LEAD-ZINC ORES PROCESS NO. 2
Crushing, Grinding, and Classifying
1. Function - simple ores such as coarsely disseminated lead;
lead-zinc, or zinc minerals occurring in low specific
gravity gangue (a type typical in the Mississippi
Valley and the Eastern United States) are crushed and
ground in closed circuit with screens or classifiers to
provide a sized feed to gravity concentrators. Fines
and middlings from the classifiers (or screens) are
concentrated by flotation (Process 4). The more
complex sulfide ores of the Western United States
require fine grinding in a closed circuit with a
classifier to free the mixtures of disseminated
minerals from the gangue, following which the ore
is selectively concentrated by flotation (Process
4) to yield lead, zinc, copper, and copper-pyrite
concentrates. Regrinding with a classifier in a closed
circuit is frequently necessary as an interim step
in the flotation treatment (Process 4).
2. Input Materials - Mined ore and water.
3. Operating Parameters -
Temperature: Ambient (mill temperature)
Pressure: Atmospheric
4. Utilities -
Q
Electrical energy: for crushing, 0.083 x 10 gjoules/
metric ton (2.3 kWhe/metric ton or 0.022 x 10 Btu/
short ton) of ore; for grinding, 0.070 x 10° joules/
metric ton (19 kWhe/metric ton or 0.18 x 106 Btu/short
ton) of ore
5. Waste Streams -
Dust, particulates in crushing
Spills in grinding circuits
Ground ore and ore slurries pass on to subsequent
concentration steps.
160
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6. EPA Source Classification Code - None
7. References -
(1) Census of Mineral Industries (1967), U. S. Department
of Commerce, Major Group 10, Table 3A, p. 10B-11, and
Table 7, p. 10B-23.
(2) Private communication with BCL staff who have visited
producers.
(3) Rausch, Donald 0., and Mariacher, Burt C., Editors, AIME
World Symposium on the Mining and Metallurgy of Lead and
Zinc, 1970, Vol 1, Mining and Concentrating of Lead and
Zinc. 1017 pp.
(4) Paone, James, Chapter on Lead, Mineral Facts and Problems,
1970, Bureau of Mines Bulletin 650, Bureau of Mines, U. S.
Department of the Interior, Washington, D.C., pp 603-620.
(5) Heindl, R. A., Chapter on Zinc, Ibid., Ref. (4), pp 805-824.
(6) Development Document for Effluent Guidelines and Standards of
Performance, Ore Mining and Dressing Industry (Draft), U. S.
Environmental Protection Agency, Washington, D.C. (prepared
by Calspan Corp., Buffalo, N. Y.), April 1975.
161
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LEAD AND ZINC - ALL TYPES OF MIXED LEAD-ZINC ORES PROCESS NO. 3
Gravity Concentration
1. Function - Lead and zinc ores mined in the Mississippi
Valley and the Eastern United States typically contain
coarsely disseminated lead and lead-zinc ores associated
with a low specific gravity gangue. In a number of cases:
practice is to save expensive grinding costs with a
preliminary gravity separation. Only the concentrates
from the gravity separator need to be finely ground for
further concentration by flotation methods. In
preparation for the preliminary gravity concentration,
the ore, after primary crushing, is fed to a secondary
crusher operating in closed circuit with screens or
classifiers to produce about a minus 4.4 cm (1-3/4 inch),
plus 0.64 cm (1/4 inch) feed size. Separated fines and
middlings are sent directly to the flotation grinding
section. The sized feed (oversize from the screens)
then goes' to the gravity concentrators which may be
either jigs or heavy-media cone separators. Media
used in the cone separators may be either ferrosilicon,
magnetite, ferrosilicon-magnetite mixtures, or fine
galena. Tailings from the gravity concentrators are
discarded.
Alternatively, the concentrates from gravity separation
may go directly to the smelter. Coarse lead concentrates
can go directly to the sintering plant.
2. Input Materials - Sized ore from the secondary crushing-
screening operation and water.
3. Operating Parameters -
Temperature: Ambient (mill temperature)
•V.
Pressure: Atmospheric
4. Utilities -
Electrical energy: for heavy-media separation, 0.020 x ,
10° joules/metric ton (0.55 kHhe/metric ton or 0.005 x 10
Btu/short ton) of ore
Consumption of ferrosilicon is about 0.35 kg/metric ton
(0.7 Ib/short ton) of feed.
162
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5. Haste Streams -
Float product from heavy-media separation or tailings discard
from jigs containing 25-50 percent solids, to tailing pond
6. EPA Source Classification Code - None
7. References -
(1) Census of Mineral Industries (1967), U. S. Department
of Commerce, Major Group 10, Table 3A, p. 10B-11, and
Table 7, p. 10B-23.
(2) Private communication with BCL staff who have visited
producers.
(3) Rausch, Donald 0., and Mariacher, Burt C., Editors, AIME
World Symposium on the Mining and Metallurgy of Lead and
Zinc, 1970, Vol 1, Mining and Concentrating of Lead and
Zinc, 1017 pp.
(4) Paone, James, Chapter on Lead, Mineral Facts and Problems,
1970, Bureau of Mines Bulletin 650, Bureau of Mines, U. S.
Department of the Interior, Washington, D.C., pp 603-620.
(5) Heindl, R. A., Chapter on Zinc, Ibid., Ref. (4), pp 805-824.
(6) Development Document for Effluent Guidelines and Standards
of Performance, Ore Mining and Dressing Industry (Draft),"
U. S. Environmental Protection Agency, Washington, D.C.
(prepared by Calspan Corp., Buffalo, N. Y.), April 1975.
163
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LEAD AND ZINC - ALL TYPES OF MIXED LEAD-ZINC ORES PROCESS NO. 4
Flotation
1. Function - Generally in U. S. practice with lead-zinc ores, the
procedure is to crush and grind the ore in closed circuit with a
classifier to a size where the disseminated ore minerals are
freed from the gangue and each other in the case of complex ores.
This is followed-by a separation of the desired mineral parti-
cles by a selective flotation process. The flotation process
entails adding chemical reagents to finely ground ore minerals
suspended in water with air bubbles. This treatment of the
surfaces of the particles makes some particles aerophyllic and
some hydrophillic so that the desired mineral particles may be
separated out of the water suspension by attachment to the air
bubbles. These float up to a froth on the surface and are scraped
off. Where several ore minerals are separated, sequential differ-
ential flotation methods are used. Reagents termed depressants
are used to change the surface characteristics of some of the
desired mineral particles so that they will not float while
another is being floated. Thus, three or more successive
flotation circuits are used to produce individual concentrates
of copper, lead, and zinc from an ore containing these three
metals. Ordinarily, each of the three circuits are similar in
that each first makes a "rougher" concentrate that is subsequently
"cleaned" and "recleaned".
2. Input Materials - Ground ore, water, and flotation reagents
such as sodium ethyl xanthate as a collector, sodium
sulfite as a zinc depressor in lead flotation, cresylic
acid as a frother, lime for pH control, zinc sulfate
conditioner in the lead flotation circuit, and copper
sulfite conditioner in the lead flotation circuit.
3. Operating Parameters -
Temperature: Ambient (mill temperature)
*
Pressure: Atmospheric
4. Utilities -
Electrical energy: for conditioning, flotation, pumping,
miscellaneous - 0.27 x 108 joules/metric ton (7.4
kWhe/metric ton or 0.07 x 106 3tu/short ton) of ore
164
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5. Waste Streams -
A large volume of tailings or gangue material remains as the
underflow from the last cell in the flotation circuit. They
are typically adjusted to a slurry which can be hydraulically
transported to a tailings pond. Generally, lead, zinc, and
copper sulfide flotation suspensions are run at a pH of 8.5-11.0
which is maintained by hydrated lime additions.
The waste stream contains dissolved solids and flotation reagents
Accidental spills of reagents are a potential source of adverse
discharge.
6. EPA Source Classification Code - None
7. References -
(1) Census of Mineral Industries (1967), U. S. Department
of Commerce, Major Group 10, Table 3A, p. 108-11, and
Table 7, p. 10B-23.
(2) Private communication with BCL staff who have visited
producers.
(3) Rausch, Donald 0., and Mariacher, Burt C., Editors, AIME
World Symposium on the Mining and Metallurgy of Lead and
Zinc, 1970, Vol 1, Mining and Concentrating of Lead and
Zinc, 1017 pp.
(4) Paone, James, Chapter on Lead, Mineral Facts and Problems,
1970, Bureau of Mines Bulletin 650, Bureau of Mines, U. S.
Department of the Interior, Washington, D.C., pp 603-620.
(5) Heindl, R. A., Chapter on Zinc, Ibid., Ref. (4), pp 805-824.
(6) Development Document for Effluent Guidelines and Standards^
of Performance. Ore Mining and Dressing Industry (Draft),
U. S. Environmental Protection Agency, Washington, D.C.
(prepared by Calspan Corp., Buffalo, N. Y.), April 1975.
165
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Mercury
The mercury mining industry has shown very variable character
in recent years. Domestic production from mines was about
28,000 flasks in 1970 (a flask is equal to 76 pounds of
mercury), almost 18,000 flasks in 1971, and only 7,286
flasks in 1972, the latest year for which production
figures are available. A total of 71 mines reported
production of mercury in 1971, but only 21 made claims in
1972. In 1975, a single, large, new operation started production
using flotation concentration in the process. This operation
represents a doubling of domestic production capacity.
Mercury occurs in almost all natural substances in the parts
per billion to parts per million range, but in order for a
"deposit" to be minable, a mercury ore must have at least 4
or 5 pounds of mercury to a ton of ore (2000-2500 parts per
million) which is many times greater than in most rocks.
The mineral in most mercury ores is cinnabar, HgS.
The product of the mercury mining and beneficiating segment
of the industry is a cinnabar concentrate or mercury metal
depending on whether or not the mining company has the
pyrometallurgical equipment necessary to win the metal from
the ore in a simple furnacing operation. Ore concentrates
may be heated in retorts, multiple-hearth roasters, or rotary
kilns which can be located at the mine and mill site or
elsewhere. If the furnacing equipment is available, mercury
metal is shipped from the mine.
166
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-------
MERCURY - CINNABAR DEPOSITS PROCESS NO. 1
Open Pit Mining
1. Function - Open pit surface mining is accomplished by the normal
drilling, blasting, digging, and loading operations. Open pit
methods have accounted for about one-third of U. S. mercury
production in recent years. However, owing to slackened demand,
many open pit mercury mines have shut down. Only two of the
lower cost open pit mines remain active. The mineral mined is
cinnabar, HgS; ores from open pit mines contain upwards of 2.5 kg
of mercury per metric ton (5 Ibs/short ton).
2. Input Materials - Explosives: amount not known precisely, about
1.75 kg/metric ton (3.5 Ib/short ton) of ore
3. Operating Parameters -
Temperature: Ambient
Pressure: Atmospheric
4. Utilities -
8
Electrical energy: about 1.55 xg10 joules/metric ton
(43 kWhe/metric ton or 0.41 x 10 Btu/short ton) of ore.
Diesel fuel (or equivalent): about 2.8 liters/metric ton
(0.67 gal/short ton) of ore
5. Waste Streams -
Emissions of mercury vapor from open deposits of cinnabar
ore through natural heat. The emission factor from
mining has been reported as 0.005 kg/metric ton (0.01
Ib/short ton) of ore.
Runoff and ground water seepage caused by precipitation.
Negligible in the arid regions where open pit mines are
currently in operation.
Overburden and gangue minerals. Silica and carbonate
minerals predominantly. Some deposits contain pyrite,
FeS2, and marcasite, FeS2- Stibnite, Sb2Sa, and orpiment,
AS2S3, occur rarely.
6. EPA Source Classification Code - None
168
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7. References -
(1) Private communication with members of the BCL staff who
have conferred with producers.
(2) Pennington, J. W., "Mercury—A Material Survey", U. S.
Bureau of Mines Circular 7941 (1959), Department of the
Interior, Washington, D.C.
(3) She!ton, John E., Chapter on Mercury, Mineral Facts and
Problems, 1965, U. S. Bureau of Mines Bulletin 630,
Department of the Interior, Washington, D.C., pp 573-581.
(4) Greenspoon, Gertrude N., Chapter on Mercury, Mineral Facts
and Problems, 1970, U. S. Bureau of Mines Bulletin 650,
Department of the Interior, Washington, D.C., pp 639-652.
(5) Development Document for Effluent Guidelines and Standards
of"Performance, Ore Mining and Dressing Industry (Draft),
U. S. Environmental Protection Agency, Washington, D.C.
(prepared by Calspan Corp., Buffalo, N. Y.), April 1975.
(6) Anderson, D.,"Emission Factors for Trace Substance,"
Report PB 230894, Springfield, Va., Nat. Tech. Infor- •
mation Service (Dec. 1973).
169
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MERCURY - CINNABAR DEPOSITS PROCESS NO. 2
Underground Mining
1. Function - Over the past few years, about two-thirds of the
mercury produced came from underground mines. The larger mines
are mined by square set stoping. Shrinkage and sub!eve! stoping
methods are also used. Ore is broken by blasting and removed by
scrapers or mechanical .loaders.
2. Input Materials - Explosives: 0.41 kg/metric ton (0.82 Ib/short
ton) of ore
3. Operating Parameters -
Temperature: Ambient
Pressure: Atmospheric
•4. Utilities -
g
Electrical energy: 2.3 x 10? joules/metric ton (64
kWhe/metric ton or 0.61 x 10 Btu/short ton) of ore
5. Waste Streams -
Ground water seepage
Water emissions from milling tailings used to backfill stopes
where such backfilling is practical
Waste rock from shafts, cross-cuts, etc.
6. EPA' Source Classification Code - None
7. References -
(1) Private communication with members of the BCL staff who have
conferred with producers.
(2) Pennington, J. W., "Mercury—A Material Survey", U. S.
Bureau of Mines Circular 7941 (1959), Department of the
Interior, Washington, D.C.
170
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(3) Shelton, John E., Chapter on Mercury, Mineral Facts and
Problems, 1965, U. S. Bureau of Mines Bulletin 630,
Department of the Interior, Washington, D.C., pp 573-581.
(4) Greenspoon, Gertrude N., Chapter on Mercury, Mineral Facts
and Problems, 1970, U. S. Bureau of Mines Bulletin 650,
Department of the Interior, Washington, D.C., pp 639-652.
(5) Development Document for Effluent Guidelines and Standards
of Performance, Ore Mining and Dressing Industry (Draft),
U. S. Environmental Protection Agency, Washington, D.C.
(prepared by Calspan Corp., Buffalo, N. Y.), April 1975.
171
-------
MERCURY - CINNABAR DEPOSITS PROCESS NO. 3
Crushing and Screening
1. Function - Crushing and screening at mines operating on fairly
high grade ores is done to prepare a sized feed for the retort
or furnace. With lower grade ores, the crushing and screening
operations also afford a means of partial separation. In most
types of ore, cinnabar breaks more readily and into smaller
particles than does the associated gangue, so that a rough
separation can be achieved by screening and discarding the over-
size waste minerals.
2. Input Materials - Mined ore
3. Operating Parameters -
Temperature: Ambient
Pressure: Atmospheric
4. Utilities -
g
Electrical energy: 0.74 x 10 joules/metric ton (20.5
kWhe/metric ton or 0.20 x 106 Btu/short ton) of ore
5. Waste Streams -
Dust, particulates in crushing and screening operation
Oversize waste minerals to stock pile
6. EPA Source Classification Code - None
7. References -
(1) Private communication with members of the BCL staff who
have conferred with producers.
(2) Pennington, J. W., "Mercury—A Material Survey", U. S.
Bureau of Mines Circular 7941 (1959), Department of the
Interior, Washington, D.C.
172
-------
(3) Shelton, John E., Chapter on Mercury, Mineral Facts and
Problems, 1965, U. S. Bureau of Mines Bulletin 630,
Department of the Interior, Washington, D.C., pp 573-581.
(4) Greenspoon, Gertrude N., Chapter on Mercury, Mineral Facts
and Problems, 1970, U. S. Bureau of Mines Bulletin 650,
' Department of the Interior, Washington, D.C., pp 639-652.
(5) Development Document for Effluent Guidelines and Standards
of~Performance. Ore Mining and Dressing Industry (Draft),
U. S. Environmental Protection Agency, Washington, D.C.
(prepared by Calspan Corp., Buffalo, N. Y.), April 1975.
173
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MERCURY - CINNABAR DEPOSITS PROCESS NO. 4
Crushing. Grinding, and Classifying
1. Function - Flotation is the most efficient way of concentrating
mercury ores, but to date it has only been used on a pilot-
plant scale. A commercial operation is scheduled to start in
Nevada in late 1975. Grinding the crushed ore in a ball or rod
mill in closed circuit with a classifier to free cinnabar from
the gangue minerals is the first step in a flotation concentrator.
In a Bureau of Mines pilot plant flotation of ore from the Hermes
mercury mine in Idaho, classifier overflows of minus 48 to minus 65
mesh were sufficient to effect a high ratio of concentration in
the flotation process, with mercury recoveries of about 90 percent.
2. Input Materials - Crushed ore and water.
3. Operating Parameters -
Temperature: Ambient
Pressure: Atmospheric
4. Utilities -
Electrical energy: not known precisely; operation has yet to be
started
5. Waste Streams -
Dust, particulates from crushing operation
Spills in the grinding-classification circuit
6. EPA Source Classification Code - None
7. References -
(1) Private communication with members of the BCL staff who
have conferred with producers.
(2) Pennington, J. W., "Mercury—A Material Survey", U. S.
Bureau of Mines Circular 7941 (1959), Department of the
Interior, Washington, D.C.
174
-------
(3) Shelton, John E., Chapter on Mercury, Mineral Facts and
Problems, 1965, U. S. Bureau of Mines Bulletin 630,
Department of the Interior, Washington, D.C., pp 573-581.
(4) Greenspoon, Gertrude N., Chapter on Mercury, Mineral Facts
and Problems, 1970, U. S. Bureau of Mines Bulletin 650,
Department of the Interior, Washington, D.C., pp 639-652.
(5) Development Document for Effluent Guidelines and Standards
of Performance, Ore Mining and Dressing Industry (Draft),
U. S. Environmental Protection Agency, Washington, D.C.
(prepared by Calspan Corp., Buffalo, N. Y.), April 1975.
175
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MERCURY - CINNABAR DEPOSITS PROCESS NO. 5
Flotation
1. Function - The flotation process (froth flotation) is one in
which ore that is ground fine enough to free the mineral values
from the gangue is agitated by rising air bubbles in cells con-
taining water, frothing reagents, and other chemical reagents
(such as collectors, activators, depressants, etc.) which cause
the ore particles to be selectively wetted by the frothing
reagent and become attached to the rising air bubbles. These
collect into a froth-on the surface where they are scraped off.
In normal practice, a "rougher" concentrate is first produced
and removed, and the tailings discarded. This "rougher" concen-
trate is then retreated in one or more "cleaner" flotation cir^
cuits to produce a finished concentrate and a tailing which is
recycled to the "rougher" flotation circuit.
2. Input Materials - Ground ore from the grinding-classifier
circuits, water, floatation reagents such as Dow
froth 250 (polypropylene glycol methyl ethers), a
frother; Z-ll (sodium isopropyl xanthate), a
collector; and lime and sodium silicate, which are
depressing agents.
3. Operating Parameters -
Temperature: Ambient
Pressure: Atmospheric
4. Utilities -
Electrical energy: not known precisely but energy usage
for analagous mineral sufide flotation processes (including
condition and pumping) is about 2.52 x 10° joules/metric
ton (7.0 kWhe/metric ton or 6.7 x 10° Btu/short ton) of
ore.
5. Waste Streams -
Mercury (cinnabar) in the tailings from the rougher cell.
Also flotation reagents in the water in the tailings
pond. In the one commercial installation planned,
these reagents would be Dowfroth 250 (polypropylene
glycol methyl ethers), a frother; Z-ll (sodium isopropyl
xanthate), a collector; and lime and sodium silicate
(depressing agents). There may also be finely divided
suspended solids which may present removal problems.
Solubilized, or dispersed colloidal or absorbed
heavy metals may also be present.
176
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6. EPA Source Classification Code - None
7. References -
(1) Private communication with members of the BCL staff who
have conferred with producers.
(2) Pennington, J. W., "Mercury—A Material Survey", U. S.
Bureau of Mines Circular 7941 (1959), Department of the
Interior, Washington, D.C.
(3) Shelton, John E., Chapter on Mercury, Mineral Facts and
Problems, 1965, U. S. Bureau of Mines Bulletin 630,
Department of the Interior, Washington, D.C., pp 573-581.
(4) Greenspoon, Gertrude N., Chapter on Mercury, Mineral Facts
and Problems, 1970, U. S. Bureau of Mines Bulletin 650,
Department of the Interior, Washington, D.C., pp 639-652.
(5) Development Document for Effluent Guidelines and Standards
of Performance, Ore Mining and Dressing Industry (Draft],
U. S. Environmental Protection Agency, Washington, D.C.
(prepared by Calspan Corp., Buffalo, N. Y.), April 1975.
177
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MERCURY - CINNABAR DEPOSITS PROCESS NO. 6
Retorting
1. Function - Retorts are inexpensive installations
for small operations treating 0.23 to 4.5 metric tons
(1/4 to 5 short tons) of ore per day. Typically,
they are manually-charged, cast-iron cylindrical (or
D-shaped in cross section) vessels, 2.1 to 2.7 meters
(7 to 9 feet) long and 25.4 to 20.5 cm (10 to 12
inches) in diameter. They are supported by
brickwork or other masonry, and are heated with a
fire box placed either below or to the side of the
retort. Mercury gas discharges through a pipe at the
closed end of the retort into an inclined, water-cooled
tube condenser. Since only a limited amount of air is
available to oxidize the sulfur, it is necessary to
add lime or iron to the retort charge to combine
with the sulfur in the ore. These additions are
particularly necessary when the sulfur content of
the ore is high.
Mercury, dust, and soot collected in the condenser
system are removed periodically and transported to
a hoe table where the impure product is mixed with
lime to recover the mercury. During this "hoeing"
operation the mercury coalesces and flows into
a sump at a low point in the table where it is
collected and bottled in flasks. To increase yield,
the residue from the hoe table is recycled by mixing
it with the ore input into the retort.
2. Input Materials - Mercury Ore crushed to 3.8 - 5.1 cm
(1-1/2 - 2 inch) maximum size
Lime or iron to combine with sulfur in the ore. Lime
additions to the hoeing table.
Fuel for the retort fire box
3. Operating Parameters -
Temperature: Retorting 377-399 C (710-750 F)
Pressure: Controlled negative pressures are
maintained in the system by means of draft
gages to prevent the escape of fumes and dust.
178
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4. Utilities -
Retorts are small inexpensive installations used by
small operators. Fuel, coal, oil or bottled gas
for retort heating is usually transported to the
site. Rate of fuel usage per ton of ore is about
the same as that for rotary furnaces (Process #7).
Electric current is used only for central and plant
auxiliaries.
5. Haste Streams -
Air Emissions: The flow of gas through the furnace and
mercury condenser is controlled by an exhaust fan
placed between the dust collector and the condenser.
Any mercury remaining in the gas is recovered by
passing the gases through wooden settling tanks
(or alternatively, cooling towers) where recovery
of mercury in the gas is achieved from a reduction in
gas velocity and a slow percolation of gas through
wetted baffles. Gases from this tank pass into the
atmosphere through a wooden stack. Mercury losses to
the atmosphere are very low when the temperature of the
waste gas is kept below 49C (120F). Mercury recovery
by this process usually equals or exceeds 98 percent.
The major loss of mercury occurs in the stack gases.
The emission factor for the retort operation is as
follows:
0.001 Kg/metric ton (0.002 Ib/short ton)
of ore processed.
Condenser Hater - The condenser cooling and wash water
may contain metallic mercury which is potentially
highly toxic, and thus requires lined lagoons for
storing this waste water and any other process waste
water.
Solid Waste - Minor amounts of mercury are entrained
in the calcine residues, minor losses occur in dusts and
spillage.
6. E.P.A. Source Classification Code - None
7. References same as Mercury - Cinnabar Deposits -
Process No. 1 - Open Pit Mining.
179
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MERCURY - CINNABAR DEPOSITS PROCESS NO. 7
Rotary Kiln Furnace Roasting of Mercury Ore
1. Function - Rotary kiln operation is most frequently used
to liberate mercury vapor from ore (alternatively
multiple hearth furnaces may be used, but they are not in
common use in the United States). The kiln is essentially
an insulated, fire-brick lined, rotating steel tube
inclined slightly to the horizontal, with gas seals
at each end. In operation, ore up to 4 cm (1-1/2
inches) in size, is fed into the kiln against a
counter current flow of hot combustion gases. Calcine
is discharged at the lower end of the kiln, while the
mercury-laden gases then pass through a condenser where
the mercury vapor is cooled below the dewpoint to form
liquid mercury. Final traces of mercury vapor remaining
in the gases from the condensers are removed in
scavenger tanks or washers and collected. Rotary
furnace installations vary greatly in capacity from
5.4-9.1 metric tons/day (6-10 short tons/day)
[from 53 cm (21 inch) diameter by 6.1 meter (20
feet) long kiln] to 150-218 metric tons (165-240
short tons/day) [from a 133 cm (72 inch) diameter
by 30.5 meter (100 feet) long kiln].
Mercury, dust, and soot collected in the condenser
system are removed periodically and transported to a
hoe table where the impure product is mixed with
lime to recover the mercury. During this "hoeing
operation" the mercury coalesces and flows into a
sump at a low point in the table where it is
collected and bottled in flasks. To increase
yield, the residue from the hoe table is returned
to the rotary kiln for reprocessing.
2. Input Materials - Mercury ore crushed to a maximum
1-1/2 inch size
180
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3. Operating Parameters -
Temperature: Gases from the rotary kiln enter the
condenser at about 500C (930F) and exit at 125C (257F)
Pressure: Slightly below atmospheric. Negative pressures
are maintained by blowers on the down stream side of
the cyclone to prevent the escape of fumes and dust.
4. Utilities -
Roasting:
Residual Fuel Oil (.Energy Equiv.) 4.4 x 103 joules/
metric ton (122 kWhe/metric ton or 1.16 x 10° Btu/
ton of ore). g
Electrical Energy 0.16 x 10 joules/metric ton
(4.4 kWhe/metric ton or 0.042 x 106 Btu/short ton)
of ore
5. Haste Streams -
Air Emissions: The major emissions of mercury occur
from the condenser stack. Others are from the hoe
table ventilation air, and emissions from the hot
calcine discharge. Emission factors for stack and
hoeing operations are as follows:
Stack - 0.16 Kg/metric ton (0.031 Ib/short ton)
Hoeing Operations: 0.01 Kg/metric ton (0.02 lb/
short ton) (6)
Water Effluent: The condenser cooling and wash-water
can contain metallic mercury which is potentially
highly toxic (Lined lagoons are recommended for storing
this waste water). The chemical composition of waste
water percolating through sinter tailings at a mine
processing 200,000 tons of ore per year was as follows:
mg/1
Nitrate 2.4
Chloride 63.8
Sulfate 2382.6
Bicarbonate 12.2
Carbonate 0
Sodium 186
Potassium 23.0
Calcium 289.6
Magnesium 294.4
Fluorides 1.7
Silica 18.0
Iron 0.02
Manganese 2.4
181
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Boron 3.7
Cyanide 0.03
Lead 0.000
Arsenic 0.000
Copper 0.08
Mercury 0.02
Total Hardness 1950.0
pH 4.8-5.7
Solid Waste: Roasted sinter from the rotary kiln is
transported to a tailings dump. As noted above under
Water Effluents, some soluble mercury may be present.
Other gangue constituents associated with cinnabar
deposits which make up this sinter are carbonate and
silicate minerals such as calcite, chalcedony, dolomite,
opalite, quartz, and serpentine.
6. E.P.A. Source Classification Code - None
7. References - Same as Mercury - Cinnabar Deposits -
Process #1, Open Pit Mining
182
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Molybdenum
Molybdenum production in the United States amounts to about 56
percent of the total world production of around 200 million
pounds per year. About 63 percent of the U.S. production is
from primary sources, namely Rocky Mountain porphyry molybdenum
deposits in Colorado and New Mexico, and the remainder as byproduct,
principally from porphyry copper deposits in the Western States
but also as byproduct from tungsten and uranium mining and
beneficiating operations. The United States is completely
self-sufficient in molybdenum and in fact exports molybdenum
products upon demand (currently low). The greatest use of
molybdenum is in the steel making industry in the form of
molybdic oxide (>75 percent) addition for "moly-content"
steels and in the form of ferromolybdenum. A relatively
small portion of the total molybdenum production is reduced
to the form of pure metal for use in molybdenum base
alloys or as alloying addition in other nonferrous
alloys. The reserves of molybdenum ores are quite large and
should afford our continued self-sufficiency in this commodity
for many years.
Two important mineral forms of molybdenum are molybdenite,
MoS2, and wulfenite, PbMoCty. An example of a commercially
important deposit of molybdenite is the Climax Mine in
Colorado where the ore contains 0.34 percent molybdenite.
Another molybdenite operation in the United States is that
at Questa, New Mexico where the mineral wulfenite also is
found. Molybdenite is the principal mineral for the recovery
of molybdenum from all operations however. Molybdenite (sulfide)
is the form associated with the concentrate produced by
differential flotation at both molybdenum - and copper-producing
operations.
183
-------
Molybdenum
Water
00
MoS2.
Molybdenum
Containing
Deposit
Molybdenite
(MoS2)
Concentrate
taming
Iron Pyrite,
Rare Earths,
Sequential
Gravity, Flotation,
& Magnetic Sep-
aration Techniques
T
7
Atmospheric Emissions
Liquid Waste
Solid Waste
Monazite
(Rare Earths)
Concentrate
-------
MOLYBDENUM - DEPOSITS CONTAINING MoSp PROCESS NO. 1
Underground Mining
1. Function - Molybdenum ore in the large underground mine at
Climax, Colorado, is mined by block caving, a method in which
the ore body is undercut to induce caving. Broken ore from
the caved area flows down "finger raises" into concrete-lined
si usher drifts. Haulage drifts are placed just below and per-
pendicular to these slusher drifts. Ore in the slusher drift
is scraped into cars on the haulage level via "drawholes" con-
necting the slusher and haulage drifts.
Smaller, vein-type deposits are mined by shrinkage and cut-
and-fill stoping methods.
2. Input Materials - Explosives: 0.145 kg/metric ton (0.29 lb/
short ton) of ore
3. Operating Parameters -
Temperature: Ambient
Pressure: Atmospheric
4. Utilities -
o
Electrical energy: 0.21 x 10g joules/metric ton (6.0
kWhe/metric ton or 0.057 x 10 Btu/short ton) of ore
Natural gas: 2 cu meters/metric ton (65 cu ft/short
ton) of ore
Liquid hydrocarbon fuels: 0.67 liter/metric ton (0.16 gal/
short ton) of ore
5. Waste Streams -
Mine water, on acid side from-oxidation of sulfides, typical
pH 4.5, may contain oil and grease, fluorides, and small
amounts of copper, manganese, and zinc in solution. Mine water
in the Climax installation goes to a tailing basin. Discharge
from the tailing basin occurs during spring snow-melt runoff.
Waste Rock from block-caving operations
185
-------
6. EPA Source Classification Code - None
7. References -
(1) Private communication with members of the BCL staff who
have conferred with producers.
(2) Development Document for Effluent Guidelines and Standards
of Performance, Ore Mining and Dressing Industry (Draft).
U. S. Environmental Protection Agency, Washington, D.C.
(prepared by Calspan Corp., Buffalo, N. Y.), April 1975.
(3) Sheridan, Eugene T., Chapter on Molybdenum, Mineral Facts
and Problems, 1970, Bureau of Mines Bulletin 650, U. S.
Department of the Interior, Washington, D.C., pp 333-346.
• (4) Hoiliday, R. W., Chapter on Molybdenum, Mineral Facts and
Problems, 1965, Bureau of Mines Bulletin 630, U. S. Depart-
ment of the Interior, Washington, D.C., pp 595-605.
(5) Hallowell, J. B., et al., Water Pollution Control in the
Primary Non-Ferrous Industry, Vol II, Aluminum, Mercury,
Gold, Silver, Molybdenum, and Tungsten, prepared for the
Office of Research and Monitoring, U. S. Environmental
Protection Agency, Washington, D.C., EPA-R2-73-247b,
September 1973.
186
-------
MOLYBDENUM - DEPOSITS CONTAINING MoS., PROCESS NO. 2
Open Pit Mining
1. Function - The two largest deposits of molybdenite, Mo$2, in the
U. S. are mined by open pit methods in much the same manner as
that outlined for copper. (Both require the removal of large
quantities of overburden.) One of these deposits, that at Cli-
max, Colorado, is mined by both open pit and underground methods;
production from this open pit is relatively new, starting in 1973.
The other large open pit deposit located at Questa, New Mexico,
also contains wulfenite, lead molybdate, PbMoO^. Both deposits
contain some ferrimolybdate, FeMoOg-HUO. The Climax, Colorado,
deposit also contains tungsten as wolframite, rare earth oxides
in the mineral monazite, tin as cassiterite, and iron pyrites,
all of which are recovered as by-products.
2. Input Materials - Explosives (ammonium-nitrate-fuel oil):
0.125 kg/metric ton (0.25 Ib/short ton) of ore (based on anala-
gous open pit copper mine operations)
3. Operating Parameters -
Temperature: Ambient
Pressure: Atmospheric
4. Utilities (based on analagous open pit copper mine operations) -
O
Electrical energy: 0.22 x 10? joules/metric ton (6.1
kWhe/metric ton or 0.058 x 10 Btu/short ton) of ore
Natural gas: 0.047 cu meter/metric ton (1.5 cu ft/short ton) of ore
Diesel fuels: 1.13 liters/metric ton (.27 gal/short ton) of ore
5. Waste Streams -
Dust, particulates from blasting, loading, etc.
No mine water is produced at the large open pit mine in Questa,
New Mexico. •
Suspended solids and dissolved ore constituents in runoff waste
water.
187
-------
Impoundment of waste water in mountain areas subject to' spring
flooding
Oxidation of exposed sulfides produces low pH acid waste water
containing increased soluble material.
Blasting decomposition products and oil and grease may be pres-
ent in waste water effluent.
Percolation of water through overburden and waste stockpile
contributes to increased dissolved materials from these sources.
There is a considerable storage problem with large amounts of
overburden in mountainous country.
6. EPA Source Classification Code - None
7. References -
(1) Private communication with members of the BCL staff who
have conferred with producers.
(2) Development Document for Effluent Guidelines and Standards
of Performance, Ore Mining and Dressing Industry (Draft),
U. S. Environmental Protection Agency, Washington, D.C.
(prepared by Calspan Corp., Buffalo, N. Y.), April 1975.
(3) Sheridan, Eugene T., Chapter on Molybdenum, Mineral Facts
and Problems, 1970, Bureau of Mines Bulletin 650, U. S.
Department of the Interior, Washington, D.C., pp 333-346.
(4) Holliday, R. W., Chapter on Molybdenum, Mineral Facts and
Problems, 1965, Bureau of Mines Bulletin 630, U. S. Depart-
ment of the Interior, Washington, D.C., pp 595-605.
(5) Hallowell, J. B., et al., Water Pollution Control in the
Primary Non-Ferrous Industry, Vol II, Aluminum, Mercury,
Gold, Silver, Molybdenum, and Tungsten, prepared for the
Office of Research and Monitoring, U. S. Environmental
Protection Agency, Washington, D.C., EPA-R2-73-247b,
September 1973.
188
-------
MOLYBDENUM - DEPOSITS CONTAINING MoQ3 PROCESS NO. 3
Crushing, Grinding, and Classifying
1. Function - Both the primary molybdenite ores and the copper
sulfide ores containing molybdenite are concentrated by flota-
tion. Accordingly, these ores are crushed, then ground in
closed circuit with a classifier (typically, a cone classifier)
so that the molybdenite mineral particles are physically sepa-
rated from associated gangue. Regrinding in circuit with a
classifier of oversize from the intermediate flotation "cleaner"
tailings classifiers is usual practice in molybdenite flotation.
2. Input Materials - Mined ore, water
3. Operating Parameters -
Temperature: Ambient
Pressure: Atmospheric
4. Utilities -
8
Electrical energy: for crushing, 0.064 xg!0 joules/metric
ton (1.8 kWhe/metric ton or 0.017 x 10 Btu/short
ton) of ore; for grinding, 0.45 x 10 ioules/metric
ton (12.6 kWhe/metric ton or 0.12 x 10 Btu/short ton) of ore
5. Haste Streams -
Dust, particulates from multistage crushings
Spills in grinding-classification circuit.
6. EPA Source Classification Code - None
7. References -
(1) Private communication with members of the BCL staff who
have conferred with producers.
(2) Development Document for Effluent Guidelines and Standards
of Performance, Ore Mining and Dressing Industry (Draft),
U. S. Environmental Protection Agency, Washington, D.C.
(prepared by Calspan Corp., Buffalo, N. Y.), April 1975.
189
-------
(3) Sheridan, Eugene T., Chapter on Molybdenum, Mineral Facts
and Problems, 1970, Bureau of Mines Bulletin 650, U. S.
Department of the Interior, Washington, D.C., pp 333-346.
(4) Holliday, R. VI., Chapter on Molybdenum, Mineral Facts and
Problems, 1965, Bureau of Mines Bulletin 630, U. S. Depart-
ment of the Interior, Washington, D.C., pp 595-605.
(5) Hallowell, J. B., et al., Water Pollution Control in the
Primary Non-Ferrous Industry, Vol II, Aluminum, Mercury,
Gold, Silver, Molybdenum, and Tungsten, prepared for the
Office of Research and Monitoring, U. S. Environmental
Protection Agency, Washington, D.C., EPA-R2-73-247b,
September 1973.
190
-------
MOLYBDENUM - DEPOSITS CONTAINING MoS0 PROCESS NO. 4
Flotation
1. Function - Molybdenite, MoS^* "is recovered from ground
ore by flotation. Flotation is usually carried out at
alkaline pH, typically 8.5 for molybdenite. It is
controlled with lime. Reagents used include collectors
which are reagents that are absorbed onto the molybdenite
particle surfaces and make these surfaces hydrophobic,
frothers such as pine oil, to aid the collector-
coated minerals to cling to rising air bubbles, and
depressants such as sodium cyanide, to supress the
flotation of minerals such as pyrite that might be
associated with molybdenite. Where there are no by-
product values in the ore, the flotation is carried
out in three separate steps: roughing, cleaning, and
recleaning. Several stages, each necessitating
regrinding and recycling, comprise each step. Final
concentrates are dewatered and dried for shipment
to plants for further processing onto molybdenum
products.
2. Input Materials - Ground ore, water, flotation reagents,
1ime for pH control
3. Operating Parameters -
Temperature: Ambient
Pressure: Atmospheric
pH of flotation slurry: 8.5
4. Utilities (includes energy costs of beneficiation of
associated mineral values) -
o
Electrical energy: for flotation; 0.19 x 10 joules/
metric ton or 0.050 x 10 Btu/short ton) of ore; for
pumping, tailings disposal, gravity classifiers, etc.,
0.18 x 10° joules/metric ton (5.0 kWhe/metric ton or
0.047 x 10° Btu/short ton) of ore
5. Haste Streams - ,
Tailings from molybdenite flotation have a pH of about
8.5; the pH is controlled with lime additions. They also
contain surfactants, cyanides (depressants),
oils, and greases, complex organic
191
-------
reagents such as xanthates and amines. Molybdenum is soluble
as the molybdate anion in basic solutions.
The solids in the tailings are finely ground. Therefore dis-
solution of soluble constituents in the ore is intensified.
The suspended solids content would also tend to be high. Since
the ore is so lean, about 0.34% Mo$2, solid tailings are volu-
minous.
Spring thaws in mountain areas may cause tailings pond overflow.
6. EPA Source Classification Code - None
7. References -
(1) Private communication with members of the BCL staff who
have conferred with producers.
(2) Development Document for Effluent Guidelines'and Standards
of Performance, Ore Mining and Dressing Industry (Draft),
U. S. Environmental Protection Agency, Washington, D.C.
(prepared by Calspan Corp., Buffalo, N. Y.), April 1975.
4
I
} (3) Sheridan, Eugene T., Chapter on Molybdenum, Mineral Facts
» and Problems, 1970, Bureau of Mines Bulletin 650, U. S.
' Department of the Interior, Washington, D.C., pp 333-346.
(4) Holliday, R. W., Chapter on Molybdenum, Mineral Facts and
Problems, 1965, Bureau of Mines Bulletin 630, U. S. Depart-
ment of the Interior, Washington, D.C., pp 595-605.
(5) Hallowell, J. B., et al., Water Pollution Control in the
Primary Non-Ferrous Industry, Vol II, Aluminum, .Mercury,
Gold, Silver, Molybdenum, and Tungsten, prepared for the
Office of Research and Monitoring, U. S. Environmental
Protection Agency, Washington, D.C., EPA-R2-73-247b,
September 1973.
192
-------
MOLYBDENUM - ORES CONTAINING MoS? PROCESS NO. 5
By-Product Recovery by Combined
Gravity-Flotation Magnetic
Separation-Concentration Techniques
1. Function - The largest U. S. deposit of molybdenite ore at
Climax, Colorado, contains iron pyrite, rare earth metals in
monozite, tungsten as wolframite, and tin as cassiterite, which
are separated by a combination of gravity, flotation, and mag-
netic separation methods. Tailings from the rougher flotation
are routed to Humphrey spirals; the concentrated heavy fractions
sluiced from the Humphrey spirals are then treated by flotation
to produce a pyrite concentrate which is marketed after being
dewatered and dried. Tailings from the pyrite flotation machine
are tabled to produce a concentrate containing monazite, tin,
and tungsten. This concentrate, in turn, is treated by flota-
tion to produce a monazite concentrate comprising rare earth
metal phosphates. The tailings from the monazite flotation are
dewatered and dried, then magnetically separated to produce a
nonmagnetic tin concentrate and a magnetic tungsten concentrate.
2. Input Materials - Slurries of tailings from the
molybdenite rougher flotation cells, water flotation
agents such as the following in pyrite flotation:
sulfuric acid, (0.018 Kg/metric ton of ore milled),
Z-3 xanthate collector (0.0005 Kg/metric ton of ore
milled), and Dowfroth 50 frother (0.0001 Kg/metric ton
of ore milled). In monazite flotation the following
reagents are used: "Armac C" collector, starch and
sulfuric acid - all at the rate of 0.0005 Kg/metric
ton of ore milled.
3. Operating Parameters -
Pyrite is removed from the heavy fractions from the
Humphrey spirals by flotation at pH 4.5. The tailings
from this step are tabled to further concentrate the
heavy fractions. The pH of.the table concentrate is
adjusted, to 1.5 and its temperature raised to 70 C
(158 F) for the flotation of monazite. Tailings from
this flotation step are dewatered, dried, and fed to
magnetic separators which yield tin (cassiterite) and
tungsten (wolframite).
4- Utilities (includes energy cost of molybdenite separation) -
g
Electrical energy: for flotation, 0.19 x 10 joules/metric
ton or 0.050 x 10° Btu/short ton) of ore; for pumping,
tailings disposal, gravity classifiers, etc., 0.18
x 10 joules/metric ton (5.0 kWhe/metric ton or
0.047 x 10 Btu/short ton) of ore 8
The magnetic separators require about 0.04 x 10 Joules/
metric ton (1.1 kWhe/metric ton or 0.011 x 10 Btu/
short ton) of feed.
193 .
-------
5. Haste Streams -
The tailings from the molybdenite flotation rougher comprising 97
percent of the ore input enter the by-products plant. Reagents
used for flotation include sulfuric acid for pH regulation,
xanthates and other collectors, starch (as a depressant for WC^).
and Dowfroth 250, a frothing agent. Effluents from by-products
plant flotation machines will have an increased amount of heavy
metals in solution because of the increase of the acidity of the
flotation slurries. Iron and manganese in solution are high. Total
suspended solids are also high.
6. EPA Source Classification Code - None
7. References -
(1) Private communication with members of the BCL staff who
have conferred with producers.
(2) Development Document for Effluent Guidelines and Standards
of Performance, Ore Mining and Dressing Industry (Draft),
U. S. Environmental Protection Agency, Washington, D.C.
(prepared by Calspan Corp., Buffalo, N. Y.), April 1975.
(3) Sheridan, Eugene T., Chapter on Molybdenum, Mineral Facts
and Problems, 1970, Bureau of Mines Bulletin 650, U. S.
Department of the Interior, Washington, D.C., pp 333-346.
(4) Hoiliday, R. W., Chapter on Molybdenum, Mineral Facts and
Problems, 1965, Bureau of Mines Bulletin 630, U. S. Depart-
ment of the Interior, Washington, D.C., pp 595-605.
(5) Hallowell, J. B., et al,, Water Pollution Control in the
Primary Non-Ferrous Industry, Vol u, Aluminum, Mercury,
Gold, Silver, Molybdenum, and Tungsten, prepared for the
Office of Research and Monitoring, U. S. Environmental
Protection Agency, Washington, D.C., EPA-R2-73-247b,
September 1973.
194
-------
Nickel
The amount of nickel consumed within the United States is approxi-
mately one-half of the free world production. While a large pro-
portion of the free-world nickel production takes place in North
America (Canada), the production of nickel in the U.S. is minimal.
The mining of the ore for this commodity, its conditioning, and the
smelting of this domestic ore to ferronickel is done at only one
place in the United States—near Riddle, Oregon. The Hanna Mining
Company and the Hanna Nickel Smelting Company, both daughter
companies of Hanna Steel Comaany as the names suggest, are the only
operators.
The mineral garnierite, H^(Ni, Mg) SiCty, is the nickel containing
member of a weathered perioaite-type rock found on Nickel Mountain,.
Riddle, Oregon. The garnierite bearing rock which averages about
1.2 percent nickel is the ore body being exploited by Hanna. The
•intensity of the green color of the rock is directly proportional
to the nickel content (other nickel minerals are associated with
the garnierite in small amounts) and efforts begin at the mine to
sort and blend ore by color to produce a uniform feed to the melt-
ing furnace (smelting).
The Hanna Company also produces ferrosilicon in an associated
operation for use in reducing and refining the ore to the ferro-
nickel end product. Coke, lime, and iron ore also are added in the
refining operation.
The product of the Hanna Companies' operations is ferronickel alloy.
195
-------
Nickel
Water
Nickel
Mountain
Ore
Open Pit
Mining
Crushing,
Screening,
Drying,
Calcining
Carbon,
Iron Ore,
Lime, &
Ferrosilicon
Addns.
1
Atmospheric Emissions
9 Liquid Waste
•
L
Refining Facility
—D Solid Waste
-------
NICKEL - NICKEL MOUNTAIN ORES PROCESS NO. 1
Open Pit Mining
1.' Function - The Hanna Mining Company mines nickel ore in an open
pit operation at Nickel Mountain near Riddle, Oregon. The
mineral garnierite, ^(Ni ,Mg)Si04, anc' severa^ associated
minerals occur in altered peridotite. Ores average around 1.2
percent nickel.
2. Input Materials - Ore at Nickel Mountain is dug without blasting.
3. Operating Parameters -
Temperature: Ambient
Pressure: Atmospheric
4. Utilities -
No energy is required to tram the ore, rather the electric
generators used to brake the tram cars in their 610 meter
(2000 ft) descent to the smelter generate electric power.
5. Waste Streams -
Ores do not have a tendency to dust because of high moisture
content.
Mine water runoff in prolonged wet weather during'the winter
season is voluminous, as much as 2,180 cu meters/day
(576,000 gal/day) to the impoundment.
Boulders of residual rock are rejected at the mine. Rejects of
submarginal ore after crushing are also made at the mine.
6. EPA Source Classification Code - None
7. References -
(1) Private communication with members of the BCL staff who have
conferred with producers.
197
-------
(2) Development Document for Effluent Guidelines and Standards
of~Performance, Ore Mining and Dressing Industry (Draft),
U. S. Environmental Protection Agency, Washington, D.C.
(prepared by Calspan Corp., Buffalo, N. Y.), April 1975.
(3) Ware, Glen C., Chapter on Nickel, Mineral Facts and Problems,
1965, Bureau of Mines Bulletin 630, U. S. Department of the
Interior, Washington, D.C., pp 607-619.
(4) Reno, Horace T., Chapter on Nickel, Mineral Facts and
Problems, 1970., Bureau of Mines Bulletin 650, U. S. Depart-
ment of the Interior, Washington, D.C., pp 347-360.
198
-------
NICKEL - NICKEL MOUNTAIN ORES BENEFICATION PROCESS NO. 2
Crushing. Screeningj Drying, and Calcining
1. Function - Ore is crushed at the mine and screened; plus 7.6
cm (3-inch) oversize is lower grade and is rejected. Under-
size is aerotrammed to the mill where it is stockpiled and
blended to obtain uniformity and, since it contains 17-25
percent moisture at this point, it is dried in large rotary
kilns. Drying and tumbling in a rotary kiln breaks up the
valuable minerals in the ore charge and it is screened again
following drying; plus 1.91 cm (3/4-inch) material is reject-
ed at this point; plus 0.79 cm (5/16-inch) material is re-
crushed and recycled; and minus 0.79 cm (5/16-inch) material
is classified as it is needed for the next step, electric
furnace reduction, into plus and minus 0.83 mm (20-mesh)
material. The plus 0.83 mm (20-mesh) material is calcined
in a rotary kiln to remove water of crystallization from the
concentrate, and to preheat it for charging into the electric
furnace. The minus 0.83 mm (20-mesh) material is calcined
and preheated in a multihearth furnace.
2. Input Materials - Broken ore at the mine site and water
3. Operating Parameters -
The calciners operate as preheaters for the electric furnace
charge so that temperatures are higher than normal, about
650-700 C (1200-1300 F).
4. Utilities -
No energy is required for crushing and screening at the mine
since all the energy used there is produced by generators in
the descending tram cars.
o
Drying consumes 144 x 10 joules/metric ton (3990 kWhe/metric
ton or 38.0 x 106 Btu/short ton) of ferronickel (46% Ni).
Calcining and preheating consumes 129 x 10^-joules/metric ton
(3590 kWhe/metric ton or 34.2 x 106 Btu/short ton) of ferro-
nickel (46% Ni).
199
-------
5. Waste Streams -
Beneficiation is dry. Emission rates from the drying, re-
grinding, and calcining steps are high. Dust emission
control devices are used on the calciners.
Water is used for belt washing and in wet scrubbers.
Oversize rejects, above 7.6 cm (3-inch) at mine screens, and
above 1.91 cm (3/4-inch) at drying screens, are voluminous.
6. EPA Source Classification Code - None
7. References -
(1) Private communication with members of the BCL staff who
have conferred with producers.
(2) Development Document for Effluent Guidelines and
Standards of Performance, Ore Miningand Dressing
Industry (Draft), U.S. Environmental Protection Agency,
Washington, D.C. (prepared by Calspan Corp., Buffalo,
N.Y.), April 1975.
(3) Ware, Glen C., Chapter on Nickel, Mineral Facts and
Problems, 1965, Bureau of Mines Bulletin 630, U.S. De-
partment of the Interior, Washington, D.C., pp 607-619.
(4) Reno, Horace T., Chapter on Nickel, Mineral Facts and
Problems, 1970, Bureau of Mines Bulletin 650, U.S. De-
partment of the Interior, Washington, D.C., pp 347-360.
200
-------
Platinum Group Metals
The United States is almost totally dependent on import platinum
and platinum-group metals since our production is only about 1 per-
cent of consumption (consumption is about 1.4 million ounces per
year). Platinum and palladium are the best known and most widely
used members of the platinum group; the other members iridium,
osmium, rhodium, and ruthenium, are less abundant. The only
current primary platinum recovery operation in the U.S. is located
in Alaska. A custom concentrator in California purchases platinum-
group ores for benefication along with their coproduct or byproduct
platinum-group ores from their own mine. Elsewhere in the United
States, platinum-group concentrates are produced as coproduct or
byproduct with gold and silver from one other mine in California
and from one in Nevada. In addition, there is platinum-group
metal recovery from the electrolytic slimes associated with
copper recovery. Copper ores in Utah, Arizona, and New Mexico
contain small quantities of platinum group metals--chiefly palla-
dium and platinum. Platinum-group metals recovery is principally
palladium and platinum from U.S. ores although a fairly new opera-
tion in Moro County, California is recovering osmium and iridium
in appreciable quantities.
201
-------
Platinum Group Metals
Water
O
ro
i
Dredging,
Screening, &
Gravity
Concentration
Platinum
Containing
Concentrate
To Further Processing & Refining
T Atmospheric Emissions
y Liquid Waste
Solid Waste
-------
PLATINUM GROUP METALS - PLACER DEPOSITS PROCESS NO. 1
Dredging, Screening, Jigging. Tabling, and Magnetic Separation
1. Function - With the exception of the recently discovered pri-
mary platinum veins in Rickey Canyon, Moro County, California
(the first primary platinum vein in the United States), which
will be mined first by open pit methods and later by under-
ground methods, the only primary mining of platinum in the
United States is the single dredging operation in the Good.-
news Bay District of Alaska. Most of the platinum group
metals in the U.S. are produced as byproducts of gold and
copper refining. It happens that the mineralization of the
"platinum" deposit in Moro County, California, also includes
the rare earth group of metals, gold and silver, tantalum,
and columbium, with rare earths having the principal mineral
value at this early stage of development.
In the Alaskan dredging operation, dredged gravels are
screened, jigged, and tabled to separate the heavy minerals
from thelighter gangue. Chromate and magnetite are separated
from the platinum group minerals by magnetic separation.
The separated platinum group concentrates are then screened
to a series of uniformly sized cuts, all of which are passed
through blowers to remove any remaining light fractions.
Concentrates assaying 90 percent platinum group metals and
gold are produced. These are shipped to a refinery.
2. Input Materials - Gravel and water from a placer deposit
3. Operating Parameters -
Temperature: Ambient
Pressure: Atmospheric
4. Utilities -
Electric Energy: (Dredging, screening, jigging, and tabling--
based on analogous operation) 1.37 x 10° joules/metric ton
(38 kWhe/metric ton or 0.36 x 106 Btu/short ton) of gravel.
(Magnetic separation) About 0.04 x 108 joules/metric ton (1.1
kWhe/metric ton or 0.01 x 10° Btu/short ton) of concentrate
5. Haste Streams -
Mining and milling in a dredge operation cannot-be considered
separately since the wet mill on board the dredge discharges
to the dredge pond.
203
-------
No reagents are used in the milling process.
The principal waste constituent from a dredge operation is
suspended solids.
6. EPA Source Classification Code - None
7. References -
(1) Private communication with members of the BCL staff who
have conferred with producers.
(2) Development Document for Effluent Guidelines and
Standards of Performance, Ore Mining and Dressing .
Industry (Draft). U.S. Environmental Protection Agency,
Washington, D.S. (prepared by Calsfan Corp., Buffalo,
N.Y.), April 1975.
(3) Platinum Metals Group Supply in Critical Materials,
Commodity Action Analysis, Aluminum, Chromium, Platinum,
Palladium; First edition, Office of Mineral Policy
Development, U.S. Department of the Interior, March
1975.
204
-------
Rare Earth Metals
The rare-earth metals group usually is considered to include
the elements with atomic numbers 57 through 71 as follows:
cerium, dysprosium, erbium, europium, gadolinium, holmium,
lanthanum, lutetium, neodynium, praseodynium, promethium,
samarium, terbium, thulium, and ytterbium. Some groups in
industry include the metals yttrium and scandium in the
rare-earth group although only yttrium has the chemical
characteristics of the rare-earths. Cerium and lanthanum
are the most abundant of the rare-earth group in U. S. ores.
The United States is self-sufficient in rare-earth metals-the
California deposits of bastnasite and other rare-earth
minerals are the world's largest known ore bodies of this
type. Production is from these deposits and from byproduct
rare-earth oxide minerals from the titanium and phosphate
production in the Southeastern U.S. and from molybdenum
production in Colorado. The annual domestic consumption of
rare-earth oxides is currently about 13,700 tons.
205
-------
Rare-Earth Metals (Thorium By-Product at Refinery)
Water
Water
ro
o
Crushing,
Grinding,
Classifying
Five-Stage
Flotation
Concentration
4
Leaching
U
To separation
of rare earth
-*»• metals by
solvent
extraction
T Atmospheric Emissions
V Liquid Waste
Solid Waste
-------
RARE EARTH METALS- DEPOSITS CONTAINING
RARE EARTHS: BASTNASITE PROCESS NO. 1
Open-Pit Mining
1. Function - Rare earth metals are produced from several sources.
Over 90 percent of U.S. production comes from the bastnasite
deposits of the Mountain Pass Area in San Bernadino County,
California. Bastnasite is a fluorcarbonate mineral containing
primarily cerium, lanthanum, neodymium, and praseodynium,
plus small amounts of samarium, gadolinium, and europium.
Rare earths also occur in monazite (Ce,La,Th,Y)P04', considerable
amounts of it are recovered as a by-product from titanium open-
pit mining and milling operations in Florida and Georgia. These
are covered in the titanium section.
There is a platinum vein deposit which contains rare earths that
is being developed at Rickey Canyon in Moro County, California.
This is a complex deposit which contains gold and silver,
tantalum and columbium besides platinum and the rare earths.
At present stage of development, the rare earths represent
the principal mineral value. The mine has been developed by
underground methods, but open pit-mining methods will supercede
these. Thus, practically all of the rare earths produced in
the United States will be mined by ordinary open-pit methods.
In the case of the bastnasite deposit at Mountain Pass, California,
ore is blasted, loaded into trucks by power shovels, and trucked
about a quarter of a mile to the mill.
2. Input Materials - Explosives 0.75 kg/metric (1.5 Ib/short ton)
of ore
3. Operating Parameters -
Temperature - Ambient
Pressure - Atmospheric
4. Utilities -
g
Electric Energy: 0.14 x 10g joules/metric ton (4.0 kWhe/
metric ton or 0.038 x 10 Btu/short ton) of ore
Fuel Oil: 23.4 liters/metric ton (5.6 gal/short ton)
of ore
207
-------
5. Waste Streams -
Dust, participate in loading and blasting
Dust controlled by water spraying
No mine discharge currently exists at the Mountain Pass,
California open-pit mine
Was.te rock storage
6. EPA Source Classification Code - None
7. References -
(1) Private communication with members of the BCL staff who
have conferred with producers.
(2) Development Document for Effluent Guidelines and Standards
of Performance, Ore Mining and Dressing Industry (Draft),
U. S. Environmental Protection Agency, Washington, D.C.
(Prepared by Calspan Corp., Buffalo, N. Y.), April 1975.
(3) The Rare Earth Elements, Yttrium and Thorium; A Materials
Survey, Bureau of Mines Information Circular No. 8476,
Bureau of Mines, U. S. Department of the Interior, 1971.
208
-------
RARE EARTH METALS - DEPOSITS CONTAINING
RARE EARTHS; BASTNASITE PROCESS NO. 2
Crushing, Grinding, Classifying, and Conditioning
1. Function - Crushing, grinding, and classifying are done at
both the 2720 metric ton (3000 - short tons)-per-day-
concentrator at Mountain Pass, Riverside County,
California, and the 91 metric ton -(100 - short tons)-
per-day concentrator at Rickey Canyon, Mono County,
California. The latter handles ore from a new mine
not yet in full production.
The crushing, grinding, and classifier section at the
Mountain Pass concentrator consists of a primary jaw
crusher in series with a Symons cone crusher, from
which a 1.6 cm (5/8-inch) feed passes to a
1.8 - by 3.0-meter (6- by 10-foot) rod mill. This
produces a minus-1.65 mm (10-mesh) material which is
fed to a Dorr classifier in closed circuit with a
2.7-meter (9-foot) by 1.5-meter (5-foot) conical ball
mill. The classifier overflow, containing 52
percent solids which are 96 percent minus 0.15 mm (100
mesh) flows to 3 heating agitators where the pulp is
heated by stages to 93 C (200 F) by using waste heat
from a diesel generating plant, supplemented by steam
from a boiler. A fourth agitator is used to cool the
slurry to 60 C (140 F) before pumping it to rougher
flotation. Heating is necessary to condition the rare
earth containing mineral, bastnasite, for flotation.
2. Input Materials .- Mined bastnasite ore, water, and steam
3. Operating Parameters -
Temperature: Ground pulp from the classifier overflow is
heated to 93 C (200 F) and then cooled to 60 C (140 F)
to condition it for flotation
Pressure: Atmospheric
209
-------
4. Utilities -
Electric Energy: Bastnasite ore preparation, crushing,
0.21 x 10°fijoules/metric ton (5.9 kWhe/metric ton or
0.056 x 10 Btu/short ton) of ore; grinding, 0.62 x
108 joules/metric tons (17.3 kWhe/metric ton or 0.16
x 10° Btu/short ton) of ore; conditioning, 0.032 x 10b
joules/metric ton (0.9 kWhe/metric ton or 0.008 x TO6
Btu/short ton) of ore
Reserve Fuel Oil: (for steam boiler) Bastnasite ore
preparation (conditioning) 1.1 liters/metric ton
(0.27 gal/short ton) of ore
5. Haste Streams -
Dust, particulates in crushing operation
Spills in grinding-classifier-heat agitator cycle
6. EPA Source Classification Code - None
7. References -
(1) Private communication with members of the BCL staff who
have conferred with producers.
(2) Development Document for Effluent Guidelines and Standards
of Performance. Ore Mining and Dressing Industry (Draft),
U. S. Environmental Protection Agency, Washington, D.C.
(Prepared by Calspan Corp., Buffalo, N. Y.), April 1975.
(3) The Rare Earth Elements, Yttrium and Thorium; A Materials
Survey, Bureau of Mines Information Circular No. 8476,
Bureau of Mines, U. S. Department of the Interior, 1971.
210
-------
RARE EARTH METALS - DEPOSITS CONTAINING
RARE EARTHS; BASTNASITE PROCESS NO. 3
Flotation
T. Function - Ground bastnasite ore from the Mountain Pass area
of San Bernadino County, California is preheated to 95 C (200 F)
and cooled to 60 C (140 F) to condition it for flotation. An
oleic-olein collector, Orzan A, and silicic acid are added to
the slurry during the conditioning. Flotation is initiated in
four Fagergren and eight Agitair rougher machines which produces
a tailing for discard. Barite is depressed during flotation,
and the froth is cleaned in five stages of Denver cells. Froth
from each cleaner advances to the next stage and tailing is
recycled countercurrently to the preceding cell. The final
flotation concentrate contains 63 percent rare earth oxides.
The operation at Rickey Canyon, .Mono County, California at
present consists of a flotation circuit augmented by various
gravity concentration and other separation steps to separate
the platinum, gold and silver, tantalite, and columbite from
the rare earths in the complex ore body which is being developed.
The wet gravity methods in current use will be replaced by air-
gravity separation methods in the near future.
2. Input Materials - Ground ore conditioned by heating for flotation,
Orzan A (oleic-olein), silicic acid, and water.
3. Operating Parameters -
Temperature: 60 C (140 F)
Pressure: Atmospheric
4. Utilities -
Electric Energy: Bastnasite flotation - 0.38fix 108 joules/
metric ton (10.6 kWhe/metric ton or 0.10 x 10 Btu/short ton)
of ore; heat conditioning, bastnasite ore - 1.13 liters/
metric ton (0.27 qal/short ton) of ore
5. Waste Streams -
Flotation tailings are discharged to a tailing pond, clarified,
and recycled back to the flotation circuit. The mill at Mountain
Pass is in a desert area and water is scarce.
211
-------
Reagents used in the flotation circuit are as follows
Frother Methyl, sobutyl carbinol
Collector N-80 oleic acid
pH Modifier Sodium carbonate (to pH 8.95)
Depressants Orzan, sodium silicofluoride
Conditioning Agent Molybdenum compound
High total solids and high fluoride content in waste water
6. EPA Source Classification Code - None
7. References -
(1) Private communication with members of the BCL staff who have
conferred with producers.
(2) Development Document for Effluent Guidelines and Standards
of Performance, Ore Mining and Dressing Industry (Draft),
U. S. Environmental Protection Agency, Washington, D.C.
(Prepared by Calspan Corp., Buffalo, N. Y.), April, 1975.
(3) The Rare Earth Elements, Yttrium and Thorium; A Materials
Survey, Bureau of Mines Information Circular No. 8476,
Bureau of Mines, U. S. Department of the Interior, 1971.
212
-------
RARE EARTH METALS - DEPOSITS CONTAINING
RARE EARTHS; BASTNASITE PROCESS NO. 4
Leaching
1. Function - Leaching the final bastnasite flotation concentrate,
which contains 63 percent rare earth oxides (REO), in 10 percent
hydrochloric acid, removes calcium and strontium carbonates and
raises the grade to 72 percent REO. A further beneficiation
to over 92 percent REO is accomplished by drying and calcin-
ing the leached concentrate in the solvent-extraction plant.
This eliminates carbonate, leaving essentially a mixture of
rare-earth oxides and fluorides.
2. Input Materials - Flotation concentrates, hydrochloric acid
3. Operating Parameters -
Temperature: Ambient
Pressure: Atmospheric
4. Utilities -
o
Electric Energy: Leaching - 0.14 x 10 joules/metric (4.0
kWhe/metric ton or 0.038 x 10° Btu/short ton) of flotation
cogcentrate; thickening and filtering - 0.004 x fi
10 joules/metric ton (0.12 kWhe/metric ton or 0.001 x 10
Btu/short ton) of flotation concentrate
5. Haste Streams -
The leach dissolves calcite (CaC03) strontianite (SrCOs), and
barite (BaSOa) from the concentrates. Chlorides in solution
(from the acid leach) are extremely high, 54,000 mg/1. Leach
waters are impounded with waste water from the solvent exchange
plant. Tellurium, not known to be present in the ore, is
dissolved in the combined waste stream at rather high concentration,
3.4 mgl. Leach circuit wastes are kept separated from flotation
circuit wastes as the very high dissolved solid concentrations
would interfere with flotation.
6. EPA Source Classification Code - None
213
-------
7. References -
(1) Private communication with members of the BCL staff who
have conferred with producers.
(2) Development Document for Effluent Guidelines and Standards
of Performance, Ore Mining and Dressing Industry (Draft),
U. S. Environmental Protection Agency, Washington, D.C.
(Prepared by Calspan Corp., Buffalo, N. Y.), April, 1975.
(3) The Rare Earth Elements, Yttrium and Thorium; A Materials
Survey, Bureau of Mines Information Circular No. 8476,
Bureau of Mines, U. S. Department of the Interior, 1971.
214
-------
Silver
The production of silver from mines in the United States is less
than one quarter of our annual consumption. The difference is
supplied by imports and reclaimed silver from various sources. In
1973, 37.4 million troy ounces were produced while 185 million
troy ounces were consumed
Mine production of silver is largely (~ 75 percent) byproduct
silver from primary base metal and gold-silver mining. The balance
is from ores classified primarily as silver ores which frequently
contain more base metal per ton than silver but of lower total
value per ton than silver.
Gold-silver ores can contain more silver than gold on a weight
basis but silver content is usually lower than gold content in such
ores. Placer gold usually contains only a little silver (commonly
less than 10 percent). Recent reports indicate a single gold-
silver mine producing more silver than gold. Currently there are
no U.S. mines reporting silver as the only product. The U.S.
reserves of silver ores are large, although silver concentrations
are quite low in most of these deposits which prevents their
exploitation under current economical and technical conditions.
215
-------
Silver
ro
Complex
Sulfide
Ore
Water
Underground
Mining
Open Pit-
Underground
Mining
Mined
Complex
Ore With
Silver
Water
Crushing,
Grinding,
Classifying
Sized
Complex
Ore With
Silver
Flotation
Concentration
Silver-
Base-
Metal
Concentrate
To Smelting
and Refining
9
I Atmospheric Emissions
/ Liquid Waste
Solid Waste
-------
SILVER - COMPLEX SULFIDE ORES PROCESS NO. 1
Underground Mining
1. Function - U.S. silver production is derived almost entirely
from low-grade and complex primary sulfide ores. Three-
fourths of this comes from ore in which lead, zinc, and
copper constitute the principal values; one-fourth comes
from ores where silver is the principal value in complex ore
containing lead, zinc, and/or copper. Mining methods are
similar to those used in mining several other metal ores.
Underground mining involves the removal of ores from deep
deposits by a number of techniques, the selection of which
depends on the characteristics of the ore body. There are
two main methods, caving and supported stoping. Caving
methods used in the mining of ore containing silver include
block caving used in large, homogeneous, structurally weak
ore bodies, and top slicing for smaller and more irregular
ore bodies. Supported stoping methods are used to mine veins
and flat deposits of silver containing ore. There are two
types, naturally supported and artifically supported.
Natural support stoping methods include open stoping for
small ore bodies and open stoping with natural pillar support
for wider ore bodies, both of which have structurally strong
foot walls (floors in bedded deposits) and hanging walls
(roofs in bedded deposits). Artifically supported stoping
methods include shrinkage stoping for steeply dipping
tabular-shaped deposits having fairly strong foot and hang-
ing walls, and little waste; cut and fill stoping for simi-
larly shaped deposits having weak walls; and timbered or
square-set stoping methods for cases where the ore is weak
and the surrounding rock is so weak that temporary timbered
support is necessary as an interim measure prior to filling
with broken waste rocks.
2. Input Materials - Nitroglycerine explosives (dynamite). About
0.5 kg/metric ton (1 Ib/short ton) of ore mined
3. Operating Parameters -
Temperature: Ambient
Pressure: Atmospheric
217
-------
4. Utilities -
Electrical Energy: Amount used varies widely depending upon
method of mining and type of ore body. Mean value estimated
to be about 0.32 x 108 joules/metric ton (9 kWhe/metric ton
or 0.086 x 106 Btu/short ton) of ore.
5. Waste Streams -
Mine water effluent
Storage of solid gangue
6. EPA Source Classification Code - None
7. References -
(1) U. S. Census of Mineral Industries, Major Group 10 (Copper,
lead, zinc, gold, and silver ores) Table 3A, pp 10B-11;
Table 7, pp 10-22.
(2) Private communication with members of the BCL staff who
have conferred with producers.
(3) Development Document for Effluent Guidelines and Standards
of Performance, Ore Mining and Dressing Industry (Draft),
U. S. Environmental Protection Agency, Washington, D.C.
(prepared by Calspan Corp., Buffalo, N. Y.), April 1975.
(4) Ryan, J. Patrick, Chapter on Silver, Mineral Facts and
Problems, Bureau of Mines Bulletin 630, Bureau of Mines,
U. S. Department of the Interior, Washington, D.C., 1965,
pp 809-821.
(5) Ageton, Robert W., Chapter on Silver, Mineral Facts and
Problems, Bureau of Mines Bulletin 650, Bureau of Mines,
Department of the Interior, Washington, D.C., 1970, pp 723-
737.
218
-------
SILVER - COMPLEX SULFIDE ORES PROCESS NO. 2
Open-Pit Mining
1. Function - U.S. silver production is derived almost entirely
from low-grade and complex primary sulfide ores. Three-fourths
of this comes from ore in which lead, zinc, and copper constitute
the principal values; one-fourth comes from ores where silver is
the principal value in complex ore containing lead, zinc, and/or
copper. Mining methods are similar to those used in mining
several other metal ores.
Open-pit mining involves the removal of ore from deposits at or
near the surface by a cycle of operations consisting of drilling
blast holes, blasting the ore, loading the broken ore onto
trucks or rail cars, and transporting it to the concentrators.
(In a few cases, blasting is not required; ore is "ripped" by
bulldozers and loaded.) Barren surface rock overlaying the
deposit must be removed to uncover the ore body; such over-
burden may be up to (and, in one case, even exceeding)152
meters (500 feet) thick.
2. Input Materials - Explosives (ammonium nitrate-fuel oil) 0.55
Kg/metric ton (1.I/short ton) of material mined.
3. Operating Parameters -
Tempe ra tu re: Amb i e n t
Pressure: Atmospheric
4. Utilities -
Typical Case -
Electric Energy: 0.22 x 108 joules/metric ton (6.1 kWhe/metric
ton or 0.058 x 10^ Btu/short ton) of ore (0.7 percent silver,
average).
Natural Gas: 0.047 cu meter/metric ton (1.5 cu ft/short ton)
of ore
Diesel Fuels: 1.13 liters/metric ton (0.27 gal/short ton) of
ore
219
-------
5. Waste Streams -
Airborne parti.culates from blasting
Water run-off (including water used for dust control in various
mining operations)
Storage of solid overburden wastes
6. EPA Source Classification Code - None exists
7. References -
(1) U. S. Census of Mineral Industries, Major Group 10 (Copper,
lead, zone, gold, and silver ores) Table 3A, pp 10B-11;
Table 7, pp 10-22. '
(2) Private communication with members of the BCL staff who
have conferred with producers.
(3) Development Document for Effluent Guidelines and Standards
of Performance, Ore Mining and Dressing Industry (Draft),
U. S. Environmental Protection Agency, Washington, D.C.
(prepared by Calspan Corp., Buffalo, N. Y.), April, 1975
(4) Ryan, J. Patrick, Chapter on Silver, Mineral Facts and
Problems, Bureau of Mines Bulletin 630, Bureau of Mines,
U. S. Department of the Interior, Washington, D.C., 1965,
pp 809-821.
(5) Ageton, Robert W., Chapter on Silver, Mineral Facts and
Problems, Bureau of Mines Bulletin 650, Bureau of Mines,
Department of the Interior, Washington, D.C., 1970, pp 723-
737.
220
-------
SILVER - COMPLEX SULFIDE ORES PROCESS NO. 3
Crushing, Grinding, and Classifying
1. Function - To prepare the mixed sulfide ores for flotation,
the ore is crushed, then ground to a fineness sufficient to
separate the valuable minerals from the gangue. A classi-
fier is placed in circuit with the grinding mills to sepa-
rate and return oversize particles for further grinding.
2. Input Materials - Ore, and water to the grinding circuits.
3. Operating Parameters - Crushing is a separate operation,
usually done dry. Grinding is usually done wet in a closed
circuit with a classifier.
Temperature: Ambient
Pressure: Atmospheric
4. Utilities -
/
Crushing: 0.11 x 10°" joules/metric ton (3.1 kWhe/metric
ton or 0.029 x 10° Btu/short ton) of ore
Grinding and Classifying: 0.56 x 10° joules/metric ton
(15.4 kWhe/metric ton or 0.15 x 106 Btu/short ton) of
ore
5. Waste Streams -
Dust, particulates from the crushing operation
Water, effluents from grinding
Waste rock (associated with crushing operation at mine shaft)
6. EPA Source Classification Code - None
7. References -
(1) U.S. Census of Mineral Industries, Major Group 10
(Copper, lead, zinc, gold, and silver ores) Table 3A,
pp 10B-11; Table 7, pp 10-22.
221
-------
(2) Private communication with members of the BCL staff who
have conferred with producers.
(3) Development Document for Effluent Guidelines and Standards
of Performance, Ore Mining and Dressing Industry (Draft),
U. S. Environmental Protection Agency, Washington, D.C.
(prepared by Calspan Corp., Buffalo, N. Y.), April 1975.
(4) Ryan, J. Patrick, Chapter on Silver, Mineral Facts and
Problems, Bureau of Mines Bulletin 630, Bureau of Mines,
U. S. Department of the Interior, Washington, D.C., 1965,
pp 809-821.
(5) Ageton, Robert W., Chapter on Silver, Mineral Facts and
Problems, Bureau of Mines Bulletin 650, Bureau of Mines,
Department of the Interior, Washington, D.C.,,1970, pp 723-
737.
222
-------
SILVER - COMPLEX SULFIDE ORE PROCESS NO. 4
Flotation
1. Function - The flotation technique may be used to separate
ground ore mineral particles from gangue mineral particles
' and from each other in complex ores if the differences in
the surface characteristics between the various ore mineral
and gangue particles are sufficiently large. In the flota-
tion process, the ground ore is agitated by rising air
bubbles in cells containing water, various oils, and chemi-
cal reagents which cause the mineral particle to be selec-
tively wetted by the oil present and become attached to the
rising air bubbles, whereupon they rise to the surface of
the cell and are scraped off. In complex ores containing
more than one ore mineral value, reagents called depressants
are used to "depress" one type mineral particle while the
other is being floated.
2. Input Materials - Ground ore, water, oils, inorganic, and
organic flotation reagents.
3. Operating Parameters - Flotation cells are operated at
ambient temperature and pressure.
4. Utilities -
Q
Electric Energy: 0.24 x 10 joules/metric ton (6.6 kWhe/
metric ton or 0.063 x 10° Btu/short ton) of ground ore input
5. Haste Streams -
Slurries containing tailings, reagent losses to tailings
Solid Tailings remaining after dewatering
6. EPA Source Classification Code - None
7. References -
(1) U.S. Census of Mineral Industries, Major Group 10
(Copper, lead, zinc, gold, and silver ores) Table 3A,
pp 10B-11; Table 7, pp 10-22. '
(2) Private communication with members of the BCL staff who
have conferred with producers.
223
-------
(3) Development Document for Effluent Guidelines and Standards
of Performance, Ore Mining and Dressing Industry (Draft)
U. S. Environmental Protection Agency, Washington, D.C.
(prepared by Calspan Corp., Buffalo, N. Y.), April 1975.
(4) Ryan, J. Patrick, Chapter on Silver, Mineral Facts and
Problems, Bureau of Mines Bulletin 630, Bureau of Mines,
U. S. Department of the Interior, Washington, D.C.,
1965 pp 809-821.
(5) Ageton, Robert W., Chapter on Silver. Mineral Facts and
Problems, Bureau of Mines Bulletin 650, Bureau of Mines,
Department of the Interior, Washington, D.C., 1970, pp 723-
737.
224
-------
Titanium
The United States use of titanium metal has increased to about
35 million pounds in 1974. However, the use of metallic
titanium is small compared to the far larger quantites of
titanium oxide used in pigments, welding rods, etc. About
3 percent of the total titanium oxide utilized (881,000
tons in 1972) was used in producing metal. Approximately
half of the oxide used is produced in domestic mines with
the balance imported.
Lode deposits of titanium minerals are currently mined in
Virginia (rutile and ilmenite together with nonmetallic
minerals of value, e.g., aplite) and New York (ilmenite
together with magnetite, an iron mineral) while placer
titanium deposits are worked in New Jersey, Georgia, and
Florida. The extensive placer deposits of heavy sands
along the Eastern coast of the U.S. are fossil beach placers
where the titanium mineralization is principally ilmenite
with some rutile and leucoxene also present. In addition,
these fossil beach placers contain zircon, ZrSiO^ monazite,
(Ce, RE, Th)P04, and other minerals which are usually recovered
as by-products.
The fossil beach placer titanium deposits are float-dredged
by creating a transient operating pond and the lode deposits
are mined by open-pit methods. Beneficiation of the mined
ores is accomplished by a variety of techniques ranging from
simple gravity procedures to complicated circuits embodying
gravity, electrostatic, flotation, and various-intensity
magnetic separation methods. The methods used in the
currently operating plants are outlined in the process flow
diagram.
225
-------
Titanium-Placer Deposits
Water
Water
t 7
1
Dredging,
Gravity
Concentration
(Wet Mill)
LJ
f Mixed ^
' Ti Minerals,
Monazite,
, and Zircon
\Concentrates
IV)
ro
t
2
Dry
Scrubbing
Electrc
Separ
Magr
Separal
Ti Mil
C
Mill:
, Drying,
>static
ation;
letic
ion of
lerals
f
U
-*J
llmenite
Concentrate
37-60% Fe
Leucoxine
Concentrate
30-40% Fe
y Atmospheric Emissions
¥ Liquid Waste
~~D Solid Waste
Rutile
Concentrate
4-10% Fe
Water
Non-
conductive
Tailings
from
Electrostatic
Separators
* 1
3
Separation
of By-Products
by Gravity
Concentration
and Magnetic
Separation
f
u
/
Monazite
Concentrates
[Rare Earth
and Thorium)
(Magnetic)
Zircon
Concentration
(Zirconium]
Non-magnetic
Tailings
from
Gravity
Concen-
tration
-------
Titanium-Lode Deposits
Water
r\i
Open Pit
Mining
y Atmospheric Emissions
y Liquid Waste
Solid Waste
Mined
llmenite-
Magnetite
Ore
»
5
Crushing,
Grinding,
Classifying,
and
Magnetic
Separation
i
i
r
w.
Magnetic
Concentrate I
Flotation
Concentration
-------
TITANIUM - HEAVY MINERAL BEACH SANDS PROCESS NO. 1
Dredging - Wet Mill Operations
1. Function - Beach-sand placers containing ilmenite
(FeO*Ti02), leucoxine (altered ilmenite), and rutile
(Ti02) are mined with floating suction or bucket-line
dredges. The dredges feed sand to a wet mill where
vibrating screens in circuit with either spiral classifiers
or laminar flow roughers and cleaners produce a mixed
heavy mineral concentrate containing ilmenite, leucoxine,
rutile, zircon (ZrS04), and monazite (which contains
rare earths and thorium). These mixed concentrates
are then sent to the "dry mill".
2. Input Materials - "Heavy sand" from placer deposits and
water. Sulfuric acid to reduce pH and aid flocculation
of colloidal slime. Final discharge of clarified
overflow neutralized with lime.
3. Operating Parameters -
Temperature: Ambient
Pressure: Atmospheric
4. Utilities -
Electrical energy: for dredging and wet mill gravity
concentration, 0.14 x 10& joules/metric ton
(3.8 kWhe/metric ton or 0.037 x 106 Btu/short ton)
of solids mined
Fuel oil, diesel fuel: for dredging and wet mill
gravity concentration, 0.54 liter/metric ton
(0.13 gal/short ton) of solids mined
5. Waste Streams -
Water used for gravity concentration is discharged to the dredge
pond. No reagents are used in beneficiation. Sands contain
organic materials which form a highly colored colloidal slime;
high levels of phosphate and organic nitrogen also are present
in the waste stream.
Waste lubricating oil from the dredge and wet mill also goes to
the dredge pond.
Oversize from screens in circuit with classifiers goes to the
dredge pond.
228
-------
6. EPA Source Classification Code - None
7. References -
(1) Private communication with members of the BCL staff who
have consulted with producers on energy requirements and
specifics of operation.
(2) Development Document for Effluent Guidelines and Standards
of Performance, Ore Mining and Dressing Industry (Draft),
U. S. Environmental Protection Agency, Washington, D.C.
(prepared by Calspan Corp., Buffalo, N. Y.), April 1975.
(3) Stamper, John W., Chapter on Titanium, Mineral Facts and
Problems, 1955, Bureau of Mines Bulletin 630, U. S. Depart-
ment of the Interior, Washington, D.C., pp 971-990.
(4) Stamper, John W., Chapter on Titanium, Mineral Facts and
Problems, 1970, Bureau of Mines Bulletin 650, U. S. Depart-
ment of the Interior, Washington, D.C., pp 773-794.
(5) Miller, Jesse A., Titanium, A Materials Survey, Bureau of
Mines Information Circular 7791, U. S. Government Printing
Office, Washington, D.C., 1957, 202 pp.
229
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TITANIUM - HEAVY MINERAL BEACH SANDS PROCESS NO. 2
Separation and Upgrading of Titanium
Minerals in the "Dry" Mill
1. Function - Bulk concentrates from the wet mill are washed free
of any remaining clay or adherent material in a scrubber plant,
following which they are dried, and then electrostatically
separated into conductive titanium mineral concentrates and
non-conductive silicate (including zircon, ZrSiO^ and monazite
mineral concentrates. The titanium mineral concentrates undergo
final separation in induced-roll magnetic separators; separation
is based on their relative magnetic properties, which in turn
is based on iron content: ilmenite has 37 to 65 percent iron,
leucoxine has 30 to 40 percent iron, and rutile has 4 to 10 per-
cent iron.
2. Input Materials - Bulk concentrate from the "wet mill"
and water.
3. Opera ting Pa ramete rs -
Temperature: (drying) 149-204 C (300-400 F)
Pressure: Atmospheric
4. Uti1ities - Dry Mill; includes separation of by-product minerals:
Electrical energy: 0.57 x 10a joules/metric ton (15.8
kWhe/metric ton or 0.15 x 10° Btu (short ton) of feed
Fuel oil and diesel oil: 14.4 liters/metric ton (3.45 gals/short
ton) of feed
5. Haste Streams -
Dust, particulates in separation operations
No water effluent from dry operations. Water effluent from
scrubbing operations. Clay and other suspended solids from
scrubbing operations. Tailings are disposed of in the next
step—separation of by-product minerals.
230
-------
6. EPA Source Classification Code - None
7. References -
(1) Private communication with members of the BCL staff who
have consulted with producers on energy requirements and
specifics of operation.
(2) Development Document for Effluent Guidelines and Standards
of Performance, Ore Mining and Dressing Industry (Draft),
U. S. Environmental Protection Agency, Washington, D.C.
(prepared by Calspan Corp., Buffalo, N. Y.), April 1975.
(3) Stamper, John W. , Chapter on Titanium, Mineral Facts and
Problems, 1965, Bureau of Mines Bulletin 630, U. S. Depart-
ment of the Interior, Washington, D.C., pp 971-990.
(4) Stamper, John W., Chapter on Titanium, Mineral Facts and
Problems, 1970, Bureau of Mines Bulletin 650, U. S.
Department of the Interior, Washington, D.C., pp 773-794.
(5) Miller, Jesse A., Titanium, A Materials Survey, Bureau of
Mines Information Circular 7791, U. S. Government Printing
Office, Washington, D.C., 1957, 202 pp.
231
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TITANIUM - HEAVY MINERAL BEACH SANDS PROCESS NO. 3
Separation of By-Product Minerals in the
Non-conductive Tailings from the
Electrostatic Separators
1. Function - The non-conductive tailings from the high tension (HT)
electrostatic separators may contain zircon (ZrO^-S^) and
monazite (a rare earth phosphate mineral which, in turn, may
contain thorium silicate in association with it).
In a typical operation, the tailings are first upgraded by
either wet or dry gravity concentration (i.e., spirals or tables),
following which they are separated from one another in induced-
roll magnetic separators. Monazite, which is slightly magnetic,
is separated from zircon, which is non-magnetic.
2. Input Materials - Tailings from the high-tension magnetic
separators and water.
3. Operating Parameters -
Temperature: Ambient
Pressure: Atmospheric
4. Utilities (includes production of titanium minerals) -
Electrical energy: 0.57 x 108 joules/metric ton (15.8
kWhe/metric ton or 0.15 x 106 Btu/short ton) of feed
Fuel oil, diesel oil: 14.4 liters/metric ton (3.45
gals/short ton) of feed
5. Waste Streams -
Dust, particulates in dry separation operations
Water effluents from wet gravity concentration, where used
Tailings (may be either wet or dry, depending on the type of
operation) from gravity concentration
6. EPA Source Classification Code - None
232
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7. References -
(1) Private communication with members of the BCL staff who
have consulted with producers on energy requirements and
specifics of operation.
(2) Development Document for Effluent Guidelines and Standards
of Performance, Ore Mining and Dressing Industry (Draft),
U. S. Environmental Protection Agency, Washington, D.C.
(prepared by Calspan Corp., Buffalo, N. Y.), April 1975.
(3) Stamper, John W., Chapter on Titanium, Mineral Facts and
Problems, 1965, Bureau of Mines Bulletin 630, U. S.
Department of the Interior, Washington, D.C., pp 971-990.
(4) Stamper, John W., Chapter on Titanium, Mineral Facts and
Problems, 1970, Bureau of Mines Bulletin 650, U. S.
Department of the Interior, Washington, D.C., pp 773-794.
(5) Miller, Jesse A., Titanium, A Materials Survey, Bureau of
Mines Information Circular 7791, U. S. Government Printing
Office, Washington, D.C., 1957, 202 pp.
233
-------
TITANIUM - LODE DEPOSITS PROCESS NO. 4
Open Pit Mining
1. Function - The single lode deposit being exploited in
the U. S. is a large ilmenite/magnetite deposit in the
Lake Sanford area, Essex County, New York (one of four
in the area). The ore body being exploited occurs as
an outcrop on the side of Sanford Hill and is mined by
conventional open pit methods. Approximately 1.1
metric tons (1.25 short tons) of waste rock must be
removed to recover 0.91 metric ton (1.0 short ton of ore.
The benches in this open pit mine are 10.7 meters (35
feet) high. Blast holes are placed so as to loosen
907 metric tons (1000 short tons) of rock. Some
secondary breakage is required. Usually drop-ball
cranes are used for this purpose, but some "mud-cap"
secondary blasting is necessary. Loosened ore is
trucked to the primary crushing operation.
2. Input Materials - Explosives, 6-8 metric tons of rock/
kilogram (3-4 Short tons/1b) of explosive. Water
impounded with tailing in an adjacent open-pit is
recycled.
Operating Parameters -
Temperature: Ambient
Pressure: Atmospheric
4. Utilities (based on an analogous operation) -
o
Electrical energy! 0.99 x 10° joules/metric ton (27.6
kWhe/metric ton or 0.26 x 106 Btu/short ton) of ore
Diesel fuel: 0.71 liter/metric ton (0.17 gal/short ton)
of ore
5. Haste Streams -
Airborne particulates from blasting and loading
Considerable amounts of water are discharged from the hillside
pit, 2650 cu meters (700,000 gals) per day.' It contains high
concentrations of oils and greases, fluorides, Kjeldahl (organic)
nitrogen, and nitrates (from nitrate-based explosives).
Solid waste is considerable, 1.25 times the amount of ore mined.
6. EPA Source Classification Code - None
234
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7. References -
(1) Private communication with members of the BCL staff who
have consulted with producers on energy requirements and
specifics of operation.
(2) Development Document for Effluent Guidelines and Standards
of~Performance, Ore Mining and Dressing Industry (Draft),
U. S. Environmental Protection Agency, Washington, D.C.
(prepared by Calspan Corp., Buffalo, N. Y.), April 1975.
(3) Stamper, John W., Chapter on Titanium, Mineral Facts and
Problems, 1965, Bureau of Mines Bulletin 630, U. S.
Department of the Interior, Washington, D.C., pp 971-990.
(4) Stamper, John W., Chapter on Titanium, Mineral Facts and
Problems, 1970, Bureau of Mines Bulletin 650, U. S.
Department of the Interior, Washington, D.C., pp 773-794.
(5) Miller, Jesse A., Titanium, A Materials Survey, Bureau of
Mines-Information Circular 7791, U. S. Government Printing
Office, Washington, D.C., 1957, 202 pp.
235
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TITANIUM - LODE DEPOSITS PROCESS NO. 5
Magnetic Separation of Magnetite from
Ilmenite and Gangue; Upgrading of
Magnetite by Magnetic Processing
1. Function - Magnetite mineral particles are freed from ilmenite
and gangue in ilmenite/magnetite ores by grinding and are
separated by magnetic processing. The sequence of operations
is as follows:
Ores are initially crushed and screened. Both undersize and
oversize are magnetically cobbed to remove nonmagnetic rock
which is discarded. Oversize is further crushed, screened,
and separated. Undersize is initially ground in rod mills in
circuit with a classifier. Final grinding of the undersize
from the classifier is done in a ball mill, after which the
ground ore is magnetically separated into magnetite concentrate,
and ilmenite mixed with gangue. The latter goes to the flota-
tion machines. The magnetite concentrates are further upgraded
by additional magnetic processing, following which they are
dewatered and sent to storage to be followed by sintering to
make a material suitable for blast furnace feed.
2. Input Materials - Mined ore, trucked from open pit mine
and water.
3. Operating Parameters -
Temperature: Ambient
Pressure: Atmospheric
4. Utilities (based on analogous operation) -
0
Electrical energy: for crushing, 0.11 x 10 joules/
metric ton (3.1 kWhe/metric ton or 0.029 x 106 Btu/
short ton) of feed, for grinding and classifying,
0.56 x 10° joules/metric ton (15.4 kWhe/metric ton
or 0.15 x 1Q6 Btu/short ton) of feed; for magnetic
separation, 0.04 x 10^ joules/metric ton (1.1 kWhe/
metric ton or 0.011 x 106 Btu/short ton) .of feed
5. Waste Streams -
Dust, particulates from crushing operations
. Waste water from dewatering of magnetite concentrates
236
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Tailings from the magnetic separators contain ilmenite and are
sent on to the flotation machines.
6. EPA Source Classification Code - None
7. References -
(1) Private communication with members of the BCL staff who
have consulted with producers on energy requirements and
specifics of operation.
(2) Development Document for Effluent Guidelines and Standards
of Performance, Ore Mining and Dressing Industry (Draft),
U. S. Environmental Protection Agency, Washington, D.C.
(prepared by Calspan Corp., Buffalo, N. Y.), April 1975.
(3) Stamper, John W., Chapter on Titanium, Mineral Facts and
Problems, 1965, Bureau of Mines Bulletin 630, U. S.
Department of the Interior, Washington, D.C., pp 971-990.
(4) Stamper, John W., Chapter on Titanium, Mineral Facts and
Problems, 1970, Bureau of Mines Bulletin 650, U. S.
Department of the Interior, Washington, D.C., pp 773-794.
(5) Miller, Jesse A., Titanium, A Materials Survey, Bureau of
Mines Information Circular 7791, U. S. Government Printing
Office, Washington, D.C., 1957, 202 pp.
237
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TITANIUM - LODE DEPOSITS PROCESS NO. 6
Separation of Ilmenite
from Gangue by Flotation
Function - Non-magnetic ilmenite and gangue particles from the
magnetic separators are upgraded in a flotation circuit con-
sisting of roughers and three stages of cleaners. The floated
ilmenite concentrate is then thickened, filtered, and dried
prior to shipping.
Input Materials - Ground ilmenite and gangue from the magnetic
separation operation and water. Flotation reaaents in the
following amounts:
Frothers
Tall oil 1.33 kg/metric ton (2.66 Ib/short ton) of ore
Fuel oil 0.90 kg/metric ton (1.80 Ib/short ton) of ore
Methyl amyl alcohol 0.030 kg/metric ton (0.16 Ib/short ton) of ore
Depressant
Sodium bifluoride 0.76 kg/metric ton (1.52 Ib/short ton) of ore
pH Modifier
Sulfuric acid 1.78 kg/metric ton (3.55 Ib/short ton) of ore
Operating Parameters -
Temperature: Ambient
Pressure: Atmospheric
Utilities (based on analogous operation) -
Electrical energy, flotation: . 0.24 x 108 joules/matric
ton (6.6 kWhe/metric ton or 0.063 x 10° Btu/short ton) of feed
Waste Streams -
High amounts of suspended solids and relatively high levels of
iron, titanium, zinc, nickel, vanadium, chromium, and selenium
238
-------
were found in the relatively voluminous waste streams from this
mill [34,800 cu meter/day (9,200,000 gals/day)]. Flotation
reagents listed in (2) Input Materials would.also be present.
Solids - mineralogically, the ore averages 32 percent ilmenite,
37 percent magnetite, 16 percent feldspar, and 15 percent iron
silicates. The latter two would be present in the slurry of
finely ground tailings emanating from the mill.
6. EPA Source Classification Code - None
7. References -
(1) Private communication with members of the BCL staff who
have consulted with producers on energy requirements and
specifics of operation.
(2) Development Document for Effluent Guidelines and Standards
of Performance, Ore Mining and Dressing Industry (Draft),
U. S. Environmental Protection Agency, Washington, D.C.
(prepared by Calspan Corp., Buffalo, N. Y.), April 1975.
(3) Stamper, John W., Chapter on Titanium, Mineral Facts and
Problems, 1965, Bureau of Mines Bulletin 630, U. S.
Department of the Interior, Washington, D.C., pp 971-990.
(4) Stamper, John W., Chapter on Titanium, Mineral Facts and
Problems, 1970, Bureau of Mines Bulletin 650, U. S.
Department of the Interior, Washington, D.C., pp 773-794.
(5) Miller, Jesse A., Titanium. A Materials Survey, Bureau of
Mines Information Circular 7791,'U. S. Government Printing
Office, Washington, D.C., 1957, 202 pp.
239
-------
Tungsten
The tungsten mineral mining and beneficiating segment of the
U.S. industry is not a large one, but it is important.
Tungsten is one of the refractory metals that is of strategic
importance in numerous and diverse applications (i.e.,
from light bulb filaments to tool bits, to the hard-facing
of and alloying in other metals). Although our primary
production of tungsten was formerly almost two-thirds of our
demand (prior to 1950), current primary production of about
4 million pounds tungsten from domestic mines represents
only about half of our demand for this metal. Much of
the current production is as byproduct concentrate from the
mining and beneficiating of ores for other metals (e.g.,
molybdenum) and presently all of the production is from our
western states, principally California and Nevada (formerly
some tungsten ores were recovered in North Carolina).
Several of the mining operations are small-scale intermittently
operating ventures which usually ship their ores to mills
operated by the larger companies. There are apt to be no
changes in this pattern for tungsten recovery since the
tungsten ore reserves in the U.S. are of the high-cost (to
process), low-grade type although there are considerable
amounts of such deposits available.
Tactite is the rock type for the principal commercial source
of tungsten in the United States. Tactites are the products
of high-temperature replacement and recrystallization of pure
or impure limestone or dolomite at or near the contact of
intrusive igneous rocks. Where the mineralization includes
tungsten, the tungsten content of the tactites occurs as
scheelite, CaWCL, often as molybdenum-containing scheelite,
Ca(W,Mo)CL; the former is the major tungsten mineral of the
U.S. *
Scheelite-bearing tactite deposits range in size from small
isolated pods scattered along a contact to massive bodies
which may contain many thousands of tons, although WO., contents
of such large ore bodies is generally low. Some ores run up
to 10 percent WO., in localized areas but overall, producing
deposits average between 0.5 and 1 percent. Lower grade ore
(about 0.3 percent WO-) can be worked when tungsten prices
are high.
The scheelite-containing tactite rock is dug, crushed and
concentrated to produce a scheelite concentrate. Ideally a
concentrate will contain about 60 percent- WO.,. Lower W0_
content concentrate can be enriched by an acfd leaching
process and chemical treatment wherein the ultimate product is
ammonium paratungstate.
240
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Tungsten
ro
Scheelite
and
Wolframite
Group
Ores
Underground
Mining
Open Pit-
Underground
Mining
Water
Water
Gravity &
Flotation Con-
centration of
Ground Ore
i
Hydro metal-
lurgical Con-
centration
V Atmospheric Emissions
y Liquid Waste
—O Solid Waste
-------
TUNGSTEN - SCHEELITE AND WOLFRAMITE GROUP ORES PROCESS NO. 1
Underground Mining
1. Function - Underground mining involves the removal of ores from
deep deposits by a number of techniques, the selection of which
depends on the characteristics of the ore body. There are two
main methods, caving and supported stoping. Caving methods used
in the mining of tungsten include block caving used in large,
homogeneous, structurally weak ore bodies, and top-slicing for
smaller and more irregular ore bodies. Supported stoping methods
are used to mine veins and flat deposits of ore. There are two
types, naturally supported and artificially supported. Natural
support stoping methods include open stoping for small ore bodies
and open stoping with natural pillar support for wider ore bodies,
both of which have structurally strong foot walls (floors in
bedded deposits) and hanging walls (roofs in bedded deposits).
Artificially supported stoping methods include shrinkage stoping
for steeply dipping tabular-shaped deposits having fairly strong
foot and hanging walls, and little waste; cut-and-fill stoping
for similarly shaped deposits having weak walls; and timbered or
square-set stoping methods for cases where the ore is weak and
the surrounding rock is so weak that temporary timbered support
is necessary as an interim measure prior to filling with broken
waste rock.
Most of the tungsten produced in the U. S. is mined by under-
ground methods. The largest producing mine, the Pine Creek Mine,
in Inyo County, California, is mined by block caving methods.
Most U. S. ore mined is scheelite ore.
2. Input Materials - Nitroglycerine explosives (dynamite): About
0.5 kg/metric ton (1 Ib/short ton) of ore mined
3. Operating Parameters -
Temperature: Ambient
Pressure: Atmospheric
242
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4. Utilities -
Electrical energy: Amount used varies widely depending
upon method of mining and type of ore body. Mean value
estimated to be about 0.32 x 108 joules/metric ton (9
kWhe/metric ton or 0.086 x 106 Btu/short ton) of ore.
5. Waste- Streams -
Mine water effluent
Storage of solid gangue
6. EPA Source Classification Code - None
7. References -
(1) Private communication with members of the BCL staff who
have consulted with producers on energy requirements and
specifics of operation.
(2) Development Document for Effluent Guidelines and Standards
of Performance, Ore Mining and Dressing Industry (Draft),
U. S. Environmental Protection Agency, Washington, D.C.
(prepared by the Calspan Corp., Buffalo, N. Y.), April 1975.
(3) Hallowell, J. B., et al., Water Pollution Control in the
Primary Non-Ferrous Metals Industry, Vol II, Aluminum,
Mercury, Gold, Silver, Molybdenum, and Tungsten. Office
of Research and Development, U. S. Environmental Protection
Agency, Washington, D.C., pp 75-113.
(4) U.S. Department of Commerce, Business and Defense Services
Administration, Materials Survey, Tungsten, December 1956.
243
-------
TUNGSTEN - SCHEELITE AND WOLFRAMITE GROUP ORES PROCESS NO. 2
Open Pit Mining
1. Function - Open pit mining involves the removal of ore from
deposits at or near the surface by a cycle of operations con-
sisting of drilling blast holes, blasting the ore, loading
the broken ore onto trucks or rail cars, and transporting it
to the concentrators. (In a few cases, blasting is not re-
quired; ore is "ripped" by bulldozers and loaded.) Barren
surface rock overlaying the deposit must be removed to uncover
the ore body.
Underground systems are sometimes used to remove ore from an
open pit. In such cases ore is mined and fed into a raise at
the bottom of the pit, giving the pit a funnel shape which is
referred to as a "gloryhole". The Round Valley Tungsten Mine
at Bishop, California, uses this method.
2. Input Materials - Explosives (ammonium nitrate-fuel oil) 0.54 kg/
metric ton (1.I/short ton) of material mined
3. Operating Parameters -
Temperature: Ambient
Pressure: Atmospheric
4. Utilities -
Typical Case -
Electrical energy: 0.22 x 108 joules/metric ton (6.1
kWhe/metric ton cr 0.058 x 106 Btu/short ton) of ore
Natural gas: 0.047 cu meter/metric ton (1.5 cu ft/short ton)
of ore
Diesel fuels: 1.13 liters/metric ton (0.27 gal/short ton) of
ore
5. Haste Streams -
Airborne particulates from blasting
244
-------
Water runoff (including water used for dust control in various
mining operations)
Storage of solid overburden wastes
6. EPA Source Classification Code - None
7. References -
(1) Private communication with members of the BCL staff who
have consulted with producers on energy requirements and
specifics of operation.
(2) Development Document for Effluent Guidelines and Standards
of Performance, Ore Mining and Dressing Industry (Draft),
U. S. Environmental Protection Agency, Washington, D.C.
(prepared by the Calspan Corp., Buffalo, N. Y.), April 1975.
(3) Hallowell, J. 8., et al., Water Pollution Control in the
Primary Non-Ferrous Metals Industry, Vol II, Aluminum.
Mercury, Gold, Silver, Molybdenum, and Tungsten, Office of
Research and Development, U. S. Environmental Protection
Agency, Washington, D.C., pp 75-113.
(4) U. S. Department of Commerce, Business and Defense Services
Administration, Materials Survey, Tungsten, December 1956.
245
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TUNGSTEN - SCHEELITE AND WOLFRAMITE GROUP ORES PROCESS NO. 3
Gravity and Flotation Concentration
1. Function - The specific gravity of tungsten minerals is high and
therefore gravity concentration methods are used primarily. How-
ever, scheelite, the principal U. S. ore, is very friable and in
the process of wet-grinding a considerable amount of slimes are
produced which reduce recovery by gravity techniques. To increase
overall recovery, the finely divided scheelite particles in the
slimes are concentrated by flotation techniques using fatty acids
as collectors.
Molybdenum and copper sulfide minerals are frequently associated
by-product minerals in the ore. After crushing and wet-grinding,
these are removed from the ore (and each other, subsequently) by
flotation methods, using xanthates as collectors and soda ash
for pH modification. Tailings from this operation are refloated
using tail oil soap as collectors to recover the scheelite.
U. S. tungsten ores have an average concentration of 0.6% tungs-
ten. There is no typical single procedure because the ores are
complex and usually require the recovery of co-products or by-
products. The concentration processes all involve the libera-
tion steps of crushing, grinding, and classifying. Grinding is
usually done either in rod mills or a combination of rod and
ball mills to avoid excessive production of fines. Following
grinding and classifying, subsequent processing depends on the
type of ore being processed; frequently only the slimes are
processed by flotation, the coarser material being concentrated
by gravity techniques. As noted above, when by-products are
present, a combination of sulfide flotation and scheelite flo-
tation is used. This is usually followed by further gravity
concentration of the scheelite concentrate.
The magnetic separation of wolframite, (Fe,Mn)W04, concentrates
and cassiterite, Sn02> concentrates as by-products from a
Colorado molybdenum ore is covered under Molybdenum - Ores Con-
taining MoS2 - Process No. 5, By-Product Recovery.
2. Input Materials - Mined tungsten ores, ores containing tungsten as
a by-product, flotation reagents (proprietary collectors and
frothers), soda ash and caustic soda for pH control, sodium
silicate (depressant for silicates), and sodium cyanide (de-
pressant for sulfides), fattv acids, xanthates and water.
246
-------
3. Operating Parameters - Flotation of scheelite is difficult as
compared to metal sulfide flotation. Density of the incoming
pulp is critical and in a typical operation is maintained at 35
percent solids. Temperature minimum is around 16 C (60 F).
The pH of the pulp is maintained between 10 and 10.2.
4. Utilities -
o
Electrical energy; for crushing, 0.11 x 10 joules/metric
ton or 0.0.29 x 10 Btu/short ton) of ore; for grinding,
0.56 x 10° joules/metric ton (15.4 kWhe/metric ton or
0-15 x 10° Btu/short ton) of ore; for gravity concentration
and flotation, 0.41 x 108 joules/metric ton (11/4 kWhe/metric ton
or 0.11 x 106 But/short ton) of ore.
5. Waste Streams -
Dust, particulates from crushing operation
Tailings from gravity and flotation concentration. Flotation
reagents
Concentrates are leached in the next beneficiation step. See
Tungsten - Scheelite and Wolframite Group Ores - Process No. 4,
Hydrometallurgical Concentration.
Suspended and dissolved solids in tailing slurry.
Voluminous solids, values in ore in the order of 1 percent.
6. EPA Source Classification Code - None
7. References -
(1) Private communication with members of the BCL staff who
have consulted with producers on energy requirements and
specifics of-operation.
(2) Development Document for Effluent Guidelines and Standards
of Performance» Ore Mining and Dressing Industry (Draft),
U. S. Environmental Protection Agency, Washington, D.C.
(prepared by the Calspan Corp., Buffalo, N. Y.), April 1975.
247
-------
(3) Hallowell, J. B., et al., Hater Pollution Control in the
Primary Non-Ferrous Metals Industry, Vol II, Aluminum,
Mercury, Gold, Silver, Molybdenum, and Tungsten, Office
of Research and Development, U. S. Environmental Protection
Agency, Washington, D.C., pp 75-113.
(4) U. S. Department of Commerce, Business and Defense Services
Administration, Materials Survey, Tungsten, December 1956.
248
-------
TUNGSTEN - SCHEELITE AND WOLFRAMITE GROUP ORES
PROCESS NO. 4
Hydrometallurgical Concentration
1. Function - There are many variations in hydrometallurgical pro-
cedures for upgrading tungsten concentrates practiced in the U.S.
Differences in the deposits require different procedures.
Scheelite concentrates from the flotation machines tend to be
low grade as compared with gravity concentrates. Calcite (cal-
cium carbonate) and apatite (calcium fluorophosphate) are the
principal contaminants in these low-grade concentrates (scheelite
concentrates seldom contain sulfides in 1 arge- amounts ). These
impurities may be leached out with acid, and the concentrates up-
graded in the process. A first-stage leach with hydrochloric
acid (HC1) removes the calcite as calcium chloride (CaClp) solu-
tion, which is discarded. A second-stage leach is used to dis-
solve the apatite [CaF(PO^)3], which is not dissolved in the
presence of calcium chloride.
The iron and manganese in the wolframite series of minerals
require a pressurized alkaline treatment of concentrates to pro-
duce sodium tungstate in solution with minimum leaching of the
other constituents. Additions of hydrochloric acid to the leach
solution causes the precipitation of solid tungstic acid (^04).
Heating to 1000 C (1830 F) decomposes the acid to tungsten tri-
oxide.
Usually, separation from by-products such as molybdenum, as well
as treatment of slimes not amenable to concentration by physical
means, necessitates the pressured alkali treatment for both types
of ores to form a synthetic scheelite.
One of the many variations of tungsten ore beneficiation proce-
dures is the hydrometallurgical treatment of low-grade scheelite
group concentrates to produce calcium tungstate. A water slurry
of scheelite concentrates from the flotation machines are digested
in a pressurized digester vessel with sodium carbonate and steam
to produce tungstate and molybdate in solution. To remove the
molybdenum, the solution is filtered and heated to 91 C (195 F) ,
and sodium sulfide is added to precipitate molybdenum. The pH
is adjusted to 3.0 with H^SO* to complete this separation. Fol-
lowing this, the hot purified solution is neutralized with
sodium hydroxide to a 9.2 pH, then treated with calcium chloride
249
-------
to precipitate calcium tungstate. Alternatively, the filtered
solution after molybdenum separation may be solvent-extracted
by a proprietary process to produce ammonium paratungstate,
which is crystallized out of solution and dried.
Input Materials - Tungsten concentrates from the flotation
operation. Hydrochloric acid for leaching out apatite and
calcite from scheelite concentrates. Sodium carbonate and
sodium sulfide in procedures which require digestion with
alkali hydroxides and removal of molybdenum as a sulfide pre-
cipitate, and water.
Operating Parameters -
In leaching scheelite with hydrochloric acid to remove calcite
and apatite, the pulp in wood-stave leach tanks contains about
60 percent solids. In the first stage of leaching, HC1
is added until the liberation of CO;? is complete. This occurs
at a pH of 2.5 - 3.0. This liquor is decanted off the settled
solids, and the concentrates are given a second leach at 91 C
(195 F) in HC1 in sufficient amounts to bring the phosphorus
content of a washed sample of concentrates to 0.03%.
In the pressured alkaline treatment, a slurry of tungsten con-
centrates is passed through a bank of pressure vessels in a con-
tinuous flow. Steam is introduced in the amounts necessary to
achieve a reacting temperature of 188 C (370 F) at a pressure
of 13.6 atmospheres (200 psi).
Utilities -
Electrical energy: 2.4 x 10 joules/metric ton (66
kWhe/metric ton or 0.63 x 10° Btu/short ton) of CaW04
Natural gas: 231 cu meters/metric ton (7400 cu ft/short
ton) of CaW04
Waste Streams -
Acid leach residues in plants using an HC1 acid leach to upgrade
flotation concentrates. High calcium and phosphorus contents.
Alkaline effluents (pH 10) in plants using pressurized alkaline
digestion; these contain high concentrations of manganese and
molybdenum.
250
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Ammonia in plants- producing ammonium paratungstate.
6. EPA Source Classification Code - None
7. References -
(1) Private communication with members of the BCL staff who
have consulted with producers on energy requirements and
specifics of operation.
(2) Development Document for Effluent Guideline and Standards
of"Performance, Ore Mining and Dressing Industry (Draft),
U. S. Environmental Protection Agency, Washington, D.C.
(prepared by the Calspan Corp., Buffalo, N. Y.), April 1975.
(3) Hallowell, J. B., et al., Hater Pollution Control in the
Primary Non-Ferrous Metals Industry, Vol II, Aluminum,
Mercury, Gold, Silver, Molybdenum, and Tungsten, Office
of Research and Development, U. S. Environmental Protection
Agency, Washington, D.C., pp 75-113.
(4) U. S. Department of Commerce, Business and Defense Services
Administration, Materials Survey, Tungsten, December 1956.
251
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Uranium
In the United States, large exploitable deposits of uranium are
found chiefly in sandstone and associated rocks. The geographical
distribution of exploitable deposits is in the Western States.
Production leaders are New Mexico, Wyoming, Colorado, and Utah in
that order. Some uranium also is taken from Alaska, Washington,
Texas, and as a minor byproduct from some Arizona copper deposits.
The domestic production of about 7 million tons of ore was reported'
for 1973. These ores averaged 0.213 percent U^g. Mills recovered
close to 14jOOO.tons, UsOs- Almost 2,300 tons of concentrate were
imported. The market is one of oversupply. However, the longer
range view is not so optimistic. Projected uranium demands would
exhaust the domestic reserves in approximately 50 years.
(Radium)
The United States was the major world producer of radium
from the Colorado Plateau carnotite deposits until in the
1920's when the high-grade pitchblend (uraninite) deposits
of the former Belgium Congo were exploited.
Currently, the uranium content of U.S. ores is recovered
while the radium content is dumped. Radium is only slightly
soluble in the leaching processes used for the recovery of
uranium and remains in the waste products. Such waste
must be handled properly to prevent contamination of
streams and underground waters. The Bureau of Mines has
conducted investigations of the problem in several mills.
The best methods to date, consist of recycling of the raffi-
nate*, providing for soil seepage, and treating the solution
with a barium salt which tends to precipitate and immobilize
the radium. The problem has not yet been solved satisfactor-
ily.
In view of the complexities of the mineralization in deposits mined
for their uranium content, the terminology of the raw material suffv
cient for description in this report is—uranium content deposit.
It will be understood that this term may be used to include addi-.
tional value minerals such as those of molybdenum, thorium and
vanadium that may occasionally occur in a few deposits.
*Raffinate. Waste liquors from ion exchange or solvent extraction
processes.
252
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Uranium processing utilizes more chemical than physical methods.
In fact, many ore processing techniques are almost wholly chemical
and are accomplished at plants that may be remote from mining sites,
A single plant might service the output from a number of mines on
a toll basis. Nevertheless, such plants and their product is
"Yellow Cake", which is composed of one of several insoluble
uranium compounds precipitated from a penultimate uranium salt in
solution. The yellow cake may be a sodium, magnesium, or an
ammonium salt. The concentrates vary from 70 to 80 percent in
their 11303 (equivalent) content and contain about 1 percent of
moisture.
253
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Uranium
Water
ro
en
Uranium
Containing
Deposits
Open Pit
. Mining
Underground
Mining
Uranium
Ores
Containing
less than
12% CaCOo
Y Atmospheric Emissions
9 Liquid Waste
Alkaline Leach
NaOH Precipi-
tation Recovery
Water
Acid Leach
Leach
Liquor
and/or
Leach
Slurry
Solvent
Extraction
Ion Exchange
Recovery
Solid Waste
-------
URANIUM - URANIUM CONTAINING DEPOSITS PROCESS NO. 1
Open Pit Mining
1. Function - Open-pit mines accounted for 63 percent of uranium
mined in the U.S. in 1973. Open-pit mining involves the re-
moval of ore from deposits at or near the surface by a cycle
of operations consisting of drilling blast holes, blasting
the ore, loading the broken ore onto trucks or rail cars,
and transporting it to the concentrators. (In a few cases,
blasting is not required; ore is "ripped" by bulldozers and
loaded.) Barren surface rock overlaying the deposit must be
removed to uncover the ore body.
Present practice is to stock-pile low-grade ores for future
use. Average uranium content of the ore is 0.2 percent
uranium oxide, UsOs, i.e.,
2. Input Materials - Explosives (ammonium nitrate-fuel oil)
0.55 kg/metric ton (1.1 Ib/short ton) of ore
3. Operating Parameters -
Temperature: Ambient
Pressure: Atmospheric
4. Utilities -
Electric Energy: 0.63 x 108 joules/metric ton (17.4 kWhe/
metric ton or 0.17 x 10^ Btu/short ton) of ore
Fuel Oil: 12.6 liters/metric ton (3.0 gals/short ton) of
ore
(NOTE: The amount of energy used per ton of ore in open-pit
uranium ore mining is higher than that in the mining of
copper ore by open-pit methods. Both reported rates of use
reflect producer's figures.)
5. Haste Streams -
Dust, particulates in blasting and loading
255
-------
The large U.S. deposits of uranium are in arid areas in the
western United States.
Open-pit mines in this area lose more water by evaporation
than they gain by seepage from aquifiers.
Radioactive nuclides are present in wastes from the mining
operations. Further details on this aspect of mining
uranium ores is covered in the next section, underground
mining of uranium ores.
6. EPA Source Classification Code - None
7. References -
(1) Private communication with members of the BCL staff who
have consulted with producers on energy requirements and
specifics of operation.
(2) Development Document for Effluent Guidelines and Standards
of Performance, Ore Mining and Dressing Industry (Draft),
U. S. Environmental Protection Agency, Washington, D.C.
(prepared by Calspan Corp., Buffalo, N. Y.), April, 1975.
(3) DeCurlo, Joseph A., and Shortt, Charles E., Chapter on
Uranium. Mineral Facts and Problems, 1970, Bureau of
Mines Bulletin 650, Bureau of Mines, U. S. Department of
the Interior, Washington, D.C., pp 219-242.
(4) Baroch, Charles T., Chapter on Uranium, Mineral Facts
and Problem, 1965, Bureau of Mines Bulletin 630, Bureau
of Mines, U. S. Department of the Interior, Washington,
D.C., pp 1007-1035.
256
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URANIUM - URANIUM CONTAINING DEPOSITS PROCESS NO. 2
Underground Mining
1. Function - Mining methods in the larger uranium ore deposits
include room and pillar, longwall retreat, and panel methods.
Modification of each are common and some features of each may
be found in all of these methods. Underground mines accounted
for 36 percent of uranium mined in the U.S. in 1973.
2. Input Materials - Explosives (Based on analogous underground mining
operation) About 0.5 kg/metric ton (1.0 Ib/short ton) of ore
3. Operating Parameters -
Temperature: Ambient
Pressure: Atmospheric
4. Utilities - (Based on analogous operations)
Electric Energy: About 1.8 x 108 joules/metric ton (50 kWhe/
metric ton or 0.47 x 10^ Btu/short ton) of ore
5. Haste Streams -
Radon gas and mine dusts present radiation hazards. Radon is
a gaseous decay product of radium. Therefore, special ventila-
tion procedures are necessary in uranium underground mines.
As mentioned in the preceding section on open-pit mining,
uranium mining is conducted primarily in arid areas. Rela-
tively few mines discharge any water. Where it is practical,
mine waste water is used as process feed water for milling.
Also, where dry mines are near the mines discharging waste
water, the discharge is often recycled to the dry mines for
in situ leaching.
Decay products present in the uranium ores include isotopes of
uranium, thorium, and radium. Therefore, build-up of these
decay products in the recycle operation accompanying ion-
exchange recovery of values from these leach solutions is in-
evitable. Accordingly, high fractions of these decay products
257
-------
particularly that of the most toxic isotope, radium 226, are
present in raw wastes from these mines.
Organics derived from carbonaceous ores are also present in
raw waste water from mines. Total dissolved solids in waste
waters may be high. Effluents may contain appreciable
concentrations of calcium and magnesium, uranium, and iron.
A considerable fraction of radium 226 remains in the .tailing
after beneficiation. The uranium content may also be too
high for safe release to the environment.
6. EPA Source Classification Code - None
7. References -
(1) Private communication with members of the BCL staff who
have consulted with producers on energy requirements and
specifics of operation.
(2) Development Document for Effluent Guidelines and Standards
of Performance, Ore Mining and Dressing Industry (Draft),
U. S. Environmental Protection Agency, Washington, D.C.
(prepared by Calspan Corp., Buffalo, N. Y.), April 1975.
(3) DeCurlo, Joseph A., and Shortt, Charles E., Chapter on
Uranium, Mineral Facts and Problems, 1970, Bureau of
Mines Bulletin 650, Bureau of Mines, U. S. Department of
the Interior, Washington, D.C., pp 219-242.
(4) Baroch, Charles T., Chapter on Uranium, Mineral Facts and
Problems, 1965, Bureau of Mines Bulletin 630, Bureau
of Mines, U. S. Department of the Interior, Washington,
D.C., pp 1007-1035.
258
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URANIUM - URANIUM CONTAINING DEPOSITS PROCESS. NO. 3
Recovery of Uranium from High Lime Ores by Alkaline Leaching
and Direct Precipitation with Caustic Soda
Function - Solutions of sodium carbonate (40-50 g/1) in an
oxidizing environment are used to leach uranium and vanadium
values from high lime content ores. Alkaline leaching is
slower than acid leaching. It, therefore, is used at higher
temperatures (80-100 C; 175-212 F) and pressures. Leaching
may take place under hydrostatic pressure at the bottom of
a pachuca tank with oxygen being supplied by air agitation;
air from a compressor is introduced at the bottom of the
tank. Alternatively the leach tank may be pressured with
oxygen. Potassium permanganate is sometimes added to the
leach when additional oxidant is required.
The alkaline leach does not react with gangue minerals,
therefore, the ore must be finely ground (to 200 mesh, 700
micrometers) to obtain exposure of the uranium minerals to
the leach.
Leach liquors are separated from residues by countercurrent
decantation, thickening, and pressurized filtration. The
leach solution is regenerated by recarbonization with sodium
bicarbonate additions. Sometimes the residues (tails and
slimes) are given a scavenging leach to improve efficiency.
After filtration, uranium is precipitated from solution. The
usual method is to add caustic soda to the solution to raise
the pH and precipitate the uranium as sodium diuranate, after
which it is filtered, washed, dried, and packaged in drums
as "yellow cake".
If vanadium is present in alkaline leached ore, the clarified
liquor is neutralized after clarification and filtration
with acid to a pH of 6, causing uranylvanadate to precipitate.
It is recovered by thickening and filtering. The precipitate
is then roasted with soda ash and carbon to reduce uranium to
insoluble U02- The soluble sodium vanadate in the roasted
mixture is separated by water leaching leaving a "yellow cake"
residuum which is a marketable uranium end product.
There are three mills using the alkaline leach process in the
United States; two of them use the caustic soda precipitation
259
-------
method described here; one uses a resin-in-pulp ion-exchange
method described under Process No. 6.
2. Input Materials - Filtered uranium-bearing solution; sodium
carbonate 40-50 g/1; air or oxygen for oxidation; and sodium
bicarbonate, 10-20 g/1 (in the regeneration of leach solution
by exposure to carbon dioxide via the recarbonation); water.
3. Operating Parameters -
Temperature: 80-100 C (176-212 F)
Pressure: Hydrostatic pressure prevailing at the bottom of a
15 to 20 M (50-65 ft) cylindrical tank agitated by a cental
airlift.
Duration of Leach: About 2 days
4. Utilities -
Electric Energy: for crushing and screening, 0.14 x 108
joules/metric ton (4.0 kWhe/metric ton or 0.038 x 106
Btu/short ton) of ore; for wet grinding, 0.75 x 10°
joules/metric ton (21 kWhe/metric ton or 0.20 x 10^
Btu/short ton) of ore; for classification, 0.07 x 10^
joules/metric ton (2.0 kWhe/metric ton or 0.019 x 106
Btu/short ton) of ore; for pressurized leaching, 0.11 x
10° joules/metric ton (3.0 kWhe/metric ton or 0.028 x
106 Btu/short ton) of ore; for filtration, 0.14 x 108
joules/metric ton (4.0 kWhe/metric ton or 0.038 x 106
Btu/short ton) of ore; for precipitation, 0.10 x 10°
joules/metric ton (2.9 kWhe/metric ton or 0.027 x 10°
Btu/short ton).of ore; for filtration, 0.07 x 108
joules/metric ton (2.0 kWhe/metric ton or 0.019 x 106
Btu/short ton) of ore; for drying, 0.07 x 108 joules/
metric ton (2.0 kWhe/metric ton or 0.019 x 105 Btu/
short ton) of ore.
Natural Gas: for crushing and screening, 1.31 cu meters/metric
ton (42 cu ft/short ton) of ore; for wet grinding, 1.64
cu meters/metric ton (52.6 cu ft/short ton) of ore; for
classification, 0.66 cu meters/metric ton (21 cu ft/short
ton) of ore; for pressurized leaching, 13.1 cu meters/
metric ton (420 cu ft/short ton) of ore; for filtration,
1.0 cu meter/metric ton (31.6 cu ft/short ton) of ore;
for drying, 8.55 cu meter/metric ton (274 cu ft/short ton)
of ore
260
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5. Waste Streams -
Stack gas from recarbonation treatment
Leach is recycled via the recarbonation loop
Alkaline leach mills discharge sodium carbonate
Waste water from sodium removal purification step
Repulped tailings to pond
A considerable fraction of radium 226 remains in the tailings.
Also the uranium content may be too high for safe release to
the environment.
6. EPA Source Classification Code - None
7. References -
(1) Private communication with members of the BCL staff who have
consulted with producers on energy requirements and specifics
of operation.
(2) Development Document for Effluent Guidelines and Standards
of Performance, Ore Mining and Dressing Industry (Draft),
U. S. Environmental Protection Agency, Washington, D.C.
(prepared by Calspan Corp., Buffalo, N.Y.), April 1975.
(3) DeCurlo, Joseph A., and Shortt, Charles E., Chapter on
Uranium, Mineral Facts and Problems, 1970, Bureau of
Mines Bulletin 650, Bureau of Mines, U. S. Department of
the Interior, Washington, D.C., pp 219-242.
(4) Baroch, Charles T., Chapter on Uranium, Mineral Facts and
Problems, 1965, Bureau of Mines Bulletin 630, Bureau
of Mines, U. S. Department of the Interior, Washington,
D.C., pp 1007-1035.
261
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URANIUM - URANIUM CONTAINING DEPOSITS PROCESS NO. 4
Acid Leaching of Uranium Ores
1. Function - Uranium ores containing less than 12 percent calcium
carbonate are acid leached.
Ores are blended, crushed, and ground to 0.6 mm (28 mesh) in
preparation for acid leaching. Some ores require an inter-
mediate roast either to burn out organic material or improve
filtering characteristics (in the case of clayey ores), or
to solubilize associated vanadium compounds (in the case of
chloride roasting of high vanadium content ores to convert
the vanadium to water-soluble sodium orthovanadate, N33V04,
so that vanadium maybe removed by water leaching prior to the
acid leaching step).
In the acid leaching operation, the ground ore is leached with
sulfuric acid either in mechanically agitated tanks or in
air-agitated columns. Oxidizers such as sodium chlorate, NaClO^,
or manganese dioxide are added to the leaching solution to
oxidize any tetravalent uranium to the hexavalent state. The
resultant leach solution slurry is classified into sand and
slime fractions in hydrocyclones, thickened, and filtered to
produce a clear pregnant liquor required for subsequent uranium
recovery.
2. Input Materials - Ground ore, 0.6 mm (28 mesh); oxidizer, sodium
chlorate 2 kg/metric ton (4 Ibs/short ton) of ore; sulfuric acid,
• 26 kg/metric ton (52 Ibs/short ton) of ore
3. Operating Parameters - Ores are leached at slightly above room
temperatures. With agitation, leaching is completed in less than
8 hours. The agitated tanks and columns operate at atmospheric
pressure.
4. Utilities -
Electric Energy: for crushing and screening, 0.15 x 108
joules/metric ton (4.2 kWhe/metric ton or 0.040 x 10b
Btu/short ton) of ore; for wet grinding, 0.20 x 108
joules/metric ton (5.6 kWhe/metric ton or 0.054 x-106
Btu/short ton) of ore; for digestion, 0.10 x 108 joules/
metric ton (2.8 kWhe/metric ton or 0.026 x 106 Btu/short
ton) of ore; for classification, 0.10 x 108 joules/
metric ton (2.8 kWhe/metric ton or 0.026 x 106 Btu/short
ton) of ore; for filtration, 0.015 x 108 joules/metric
ton (0.42 kWhe/metric ton or 0.004 x 106 Btu/short ton)
of ore
262
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Natural Gas: for crushing and screening, 0.36 cu meters/
metric ton (11.6 cu ft/short ton) of ore; for wet
grinding, 0.52 cu meters/metric ton (16.8 cu ft/short
ton) of ore; for digestion, 2.6 cu meters/metric ton
(84 cu ft/short ton) of ore; for classification, 0.53
cu meter/metric.ton (17 cu ft/short ton) of ore; for
filtration, 0.34 cu meter/metric ton (11 cu ft/short ton)
of ore
5. Waste Streams -
Recycling of acid leach liquor is not practical because high
concentrations of solutes interfere. Neutralization of acid
waste liquors is necessary if seepage or discharge of wastes
take place.
With the exception of the bulk of uranium isotopes, the radio-
active decay products, including the most toxic isotope, radium
226, remain in the tailings.
6. EPA Source Classification Code - None
7. References -
(1) Private communication with members of the BCL staff who
have consulted with producers on energy requirements and
specifics of operation.
(2) Development Document for Effluent Guidelines and Standards
of Performance, Ore Mining and Dressing Industry (Draft),
U. S. Environmental Protection Agency, Washington, D.C.
(prepared by Calspan Corp., Buffalo, N. Y.), April 1975.
(3) DeCurlo, Joseph A., and Shortt, Charles E., Chapter on
Uranium, Mineral Facts and Problems, 1970, Bureau of
Mines Bulletin 650, Bureau of Mines, U. S. Department of
the Interior, Washington, D_C., pp 219-242.
(4) Baroch, Charles T., Chapter on Uranium, Mineral Facts
and Problem, 1965, Bureau of Mines Bulletin 630, Bureau
of Mines, U. S. Department of the Interior, Washington,
D. C., pp 1007-1035.
263
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URANIUM - URANIUM CONTAINING DEPOSITS PROCESS NO. 5
Solvent Extraction of Uranium from the
Pregnant Leach Solution
1. Function - Direct precipitation of uranium by raising the pH is
effective only with the alkaline leach (which is described in
a previous section, Process No. 3). If it were applied to
the acid leach, most heavy metals, particularly iron, would
be precipitated as contaminants. To avoid this, uranium (or
vanadium and molybdenum) is concentrated by a factor of
five or more by solvent extraction or ion exchange. The latter
is described in the next section, Process No. 6
In the solvent extraction process, polar solvents such as
tertiary amines or alkylphosphates in a nonpolar diluent such
as kerosine unite with uranium salts in the clarified aqueous
leach when the two immersible mediums are mixed. After mixing,
the supernatent uranium-loaded organic layer is decanted for
stripping.
The reverse of solvent extraction is accomplished in the stripping
step. The pregnant organic solvent is stripped with an aqueous
sodium chloride solution. In turn, uranium oxide is precipitated
from this aqueous solution with ammonia. The precipitate is
filtered, dried, and packaged in drums as "yellow cake".
2. Input Materials - Pregnant leach solution; kerosine (nonpolar
diluent for polar solvents) 1.75 liters/metric ton (0.42 gals/
metric ton) of ore; polar solvents, tertiary amines, alkyl
phosphates; sodium chloride (in stripping solution), 4.4 kq/
metric ton (8.8 Ibs/short ton) of ore; ammonia (for precip-
itating uranium oxide from the stripping solution), 0.8 kg/
metric ton (1.6 Ibs/short ton) of ore; water.
3. Operating Parameters -
Temperature: Room temperature
Pressure: Atmospheric
264
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4. Utilities - Amount used based on ore containing 0.20 percent
uranium oxide
o
Electric Energy: for solvent extraction, 0.061 x 10 joules/
metric ton (1.7 kWhe/metric ton or 0.016 x 106 Btu/short
ton) of ore; for stripping, 0.026 x JO8 joules/metric ton
(0.73 kWhe/metric ton or 0.007 x 106 Btu/short ton) of
ore; for precipitation, 0.018 x 108 joules/metric ton
(0.51 kWhe/metric ton or 0.005 x 106 Btu/short ton) of
ore; for drying, 0.052 xJO8 joules/metric ton (1.5 kWhe/
metric ton or 0.014 x 10b Btu/short ton) of ore
Natural Gas: for drying, 8.14 cu meters/metric ton (261 cu
ft/short ton) of ore
5. Waste Streams -
Acid leach mills discharge a portion of the acid leach.
Excess free acid in leach liquor and extraction raffinates
(non-soluble portions) may be recycled. Acid may be used to
condition incoming ores containing acid consuming gangue.
Sulfates, however, remain.
Loss of kerosine solvents is in the amount of 1/2000th of water
usage. Also losses of tertiary amines and alkyl phosphates occur
which are toxic to fish.
Repulped tailings from preceding acid leach contain radium,
thorium, and uranium, organics from carbonaceous ores, chlorides,
nitrides, and phosphates, and both light and heavy metals
6. EPA Source Classification Code - None
7. References -
(1) Private communication with members of the BCL staff who
have consulted with producers on energy requirements and
specifics of operation.
(2) Development Document for Effluent Guidelines and Standards
of Performance. Ore Mining and Dressing Industry (Draft),
U. S. Environmental Protection Agency, Washington, D.C.
(prepared by Calspan Corp., Buffalo, N. Y.), April 1975.
(3) DeCurlo, Joseph A., and Shortt, Charles E., Chapter on
Uranium, Mineral Facts and Problems, 1970, Bureau of
Mines, U. S. Department of the Interior, Washington, D.C.,
pp 219-242.
265
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(4) Baroch, Charles T., Chapter on Uranium, Mineral Facts
and Problems, 1965, Bureau of Mines Bulletin 630, Bureau
of Mines, U. S. Department of the Interior, Washington,
D.C., pp 1007-1035.
266
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URANIUM - URANIUM- CONTAINING DEPOSITS ' PROCESS NO. 6
Ion-Exchange Recovery of Uranium from
Pregnant Leach Solution (Including
the Resin-in-Pulp Ion-Exchange Process)
Function - Ion exchange is based upon the same principle as
solvent extraction. Polar organic molecules (in the case of
solvent extraction) or polymers (in the case of a resin) exchange
a mobile ion in their structure for an ion in the leach solution
which either has a greater charge or smaller ionic radius. In
the ion exchange process, the exchange of ions is between the
leach solution and an insoluble resin. It is used to concentrate
uranium oxide in both acid and alkaline leach solutions. The
method is particularly adaptable to the removal of small amounts
of solutes from large volumes of solutions. Uranium is in the
leach solution as an oxidized ion complexed with an ionic radical
to form trisulfates in acid leach solutions or tricarbonates in
alkaline leach solutions. These complexes react with anion
exchange resins which absorb the uranium anions. This is done
in two ways; either a clarified pregnant uranium solution is
passed through fixed packed columns of resins, or pulp-containing
slimes and dissolved uranium is concentrated using the "resin-
in-pulp" method. In the "resin-in-pulp" process, spherical-
shaped resin particles [between 1.65 and 0.83 mm (10 and 20
mesh) in size] are oscillated in baskets in the slimy pregnant
pulp. The oscillation prevents accumulation of the solid
slimes between the resin particles. The "resin-in-pulp" method
eliminates the need for clarification.
Vanadium and molybdenum, common constituents in uranium ores,
also may be present in the leach solution as oxidized ions com-
plexed with anionic radicals. While they also react anionically
with the exchange resins, the relative degree of affinity for
exchange resins can be changed radically by changes in pH of the
leach and other controllable factors. Thus, variations in pH,
redox potential, multiple columns, and periods of reaction are
used to make an ion-exchange process specific for a desired
product.
After absorption of the uranium, the resin is eluted with a
dilute solution of sulfuric acid and sodium chloride. The values
are precipitated with a base or hydrogen peroxide. Ammonia is
267
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preferred by most mills. Partial neutralization with calcium
hydroxide, followed by magnesium hydroxide precipitation, is
also used. In the latter case, the resultant solution is
treated with milk-of-lime to adjust pH and to remove iron,
which is filtered off. Magnesia is added to the clarified
solution to precipitate yellow cake. Following filtration,
the precipitate is washed with an ammonium sulfate solution and
later, water. The yellow cake is then dried on drum driers and
with infrared heaters.
Input Materials - Pregnant leach solution; resin (recycled);
sulfuric. acid (elution), 2.6 kg/metric ton (5.2 Ibs/short ton)
of ore processed; sodium chloride (elution), 10.6 kg/metric ton
(21.2 Ibs/short ton) of ore processed; lime (precipitation),
2 kg/metric ton (4 Ibs/short ton) of ore processed; ammonia
(precipitation), 0.8 kg/metric ton (1.6 Ibs/short ton) of ore
processed
Operating Parameters -
Content of pH and redox potential of pregnant solutions is
critical. For example, at pH 9, a particular resin will
absorb 7 times more vanadium than uranium from a leach solu-
tion; at pH 11, the ratio is reversed, with 33 times as much
uranium as vanadium being captured.
4. Utilities -
Electrical Energy: for ion exchange, 0.27 x 108 joules/metric
ton (7.5 kWhe/metric ton or 0.071 x 106 Btu/short ton)
of ore processed; for stripping, first precipitation and
filtration, second precipitation and filtration, 0.17 x
10° joules/metric ton (4.6 kWhe/metric ton or 0.044 x
10*5 Btu/short ton) of ore processed; for drying, 0.083 x
10° joules/metric ton (2.3 kWhe/metric ton or 0.022 x 10°
Btu/short ton) of.ore processed
Natural Gas: for stripping, first precipitation and filtra-
tion, second precipitation and filtration, 1.87 cu meters/
metric ton (60 cu ft/short ton) of ore processed; for
drying, 7.0 cu meters/metric ton (224 cu ft/short ton) of
ore processed
268
-------
5. Haste Streams -
Radium constituents of the ore remain in the raffinate and is a
serious liquid waste emissions problem.
Vanadium, if present in the ore, and hence in the pregnant leach,
will remain in the raffinate. If present in recoverable amounts,
the raffinate will undergo solution or solvent extraction.
Worn out resins are occasionally discarded.
Solid tailings from resin-in-pulp ion exchange operations remain
with the raffinate.
Other metals, organics, ion-exchange resins (about 30 ppm) appear
in the waste streams. Suspended solids also are on the high side.
6. EPA Source Classification Code - None
7. References -
(1) Private communication with members of the BCL staff who
have consulted with producers on energy requirements and
specifics of operation.
(2) Development Document for Effluent Guidelines and Standards
of Performance, Ore Mining and Dressing Industry (Draft).
U. S. Environmental Protection Agency, Washington, D.C.
(prepared by Calspan Corp., Buffalo, N. Y.), April 1975.
(3) DeCurlo, Joseph A., and Shortt, Charles E., Chapter on
Uranium, Mineral Facts and Problems, 1970, Bureau of Mines
Bulletin 650, Bureau of Mines, U. S. Department of the
Interior, Washington, D.C., pp 219-242T
(4) Baroch, Charles T., Chapter on Uranium, Mineral Facts and
Problems, 1965, Bureau of Mines Bulletin 630, Bureau of
Mines, U. S. Department of the Interior, Washington, D.C.,
pp 1007-1035.
269
-------
Vanadium
The United States has been a leading producer of vanadium
for over two decades. In this commodity, we are almost
self-sufficient although some vanadium materials, principally
ferrovanadium, continue to be imported. The consumption of
vanadium in the U.S. is approaching 5500 tons per year.
Domestic production falls about 500 to 600 tons per year
short of that amount. The bulk of the domestic production is
as byproduct vanadium from such sources as uranium-vanadium
ores, vanadium-bearing oil residues, spent catalysts, vanadium-
bearing residues from titanium dioxide and titanium
tetrachloride production, vanadium-containing slags, and
vanadium-bearing ferrophosphorus obtained in elemental
phosphorus production.
Vanadium is about twice as abundant as copper and zinc, and
ten times as abundant as lead. However, it is quite dispersed
for the most part which makes the recovery impractical from
many of its known "rich" concentrations except as byproduct
in the recovery of other materials. The single U.S. exception
to the above is the Potash Sulfur Springs (also known as
Wilson Springs), deposit in Garland County, Arkansas (near
Hot Springs). Here the vanadium ore which contains about 1
percent ^2®$ equivalent, occurs as poorly defined bodies in
irregular masses of argil lie altered rock of both an igneous
intrusion (alkalic) and the bordering sedimentary strata.
The ore rarely occurs as discrete vanadium minerals but
those that have been identified are: montroseite, fervanite,
and hewettite. Due to these complexities, the raw material
for the purposes of this report is termed, complex vanadium
mineral deposit.
The mined ore from the Potash Sulfur Springs deposit is
processed in a Hot Springs Arkansas processing plant (which
also handles byproduct ferrophosphorus obtained in elemental
phosphorus production, for vanadium recovery) to result in
pure vanadium oxide (99.8 percent) or ammonium metavanadate,
NH4V03. The plant can also produce a technical grade
vanadium pentoxide (86 percent V^Oc minimum) but does not
usually do so. Thus the usual products are:
(a) Pure vanadium oxide
(b) Ammonium metavanadate
270
-------
Vanadium
ro
Complex
Vanadium
Minerals
Deposit
Open Pit Mining
LJ
Water
Crushing,
Drying,
Screening, &
Grinding
Sized
Vanadium
Ore
Water
i
Hydro-
metallurgical
Processing
Vanadium
Pentoxide,
V2°5
T Atmospheric Emissions
P Liquid Waste
Solid Waste
-------
VANADIUM - COMPLEX VANADIUM MINERAL DEPOSIT PROCESS NO. 1
Open Pit Mining
1. Function - Most of the vanadium mined in the U. S. was produced
from the uranium-vanadium deposits of the Colorado Plateau and
from the complex Potash Sulfur Springs vanadium mineral deposit
near Hot Springs, Arkansas. Recovery of vanadium from the carno-
tite ores of the Colorado Plateau are covered under "Uranium".
The Arkansas deposit is the only U. S. deposit mined for vanadium
only. Mining is by open pit methods using standard drilling,
blasting, digging, and loading equipment. The deposit is not
uniform. It contains alternate "pockets" of lean and rich ores
necessitating assays of drill holes spaced at 6.1 meters
(20-ft) centers. Ore is produced in a controlled mix to
provide a uniform feed to the mills.
2- Input Materials (based on analogous operations) - Explosives:
about 0.5 kg/metric ton (1.0 Ib/short ton) of ore; water.
3. Operating Parameters -
Temperature: Ambient
Pressure: Atmospheric
4- Utilities (based on analogous operations) -
Electrical energy: 0.22 x 108 .joules/metric ton (6.0 kWhe/
metric ton or 0.057 x 10° Btu/short ton) of ore
Diesel fuel (or equivalent): 1.2 liters/metric ton (0.28
gal/short ton) of ore
5. Haste Streams -
Air emissions normally associated with open pit mining: dust,
particulates from blasting and loading operations
Raw mine water effluent flows at the rate of 11.3 cu meters/
min (3000 gals/min). Manganese content is high, 6.8 mg/liter.
Owing to the "pockety" nature of the deposit, waste rock may be
appreciable.
272
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6. EPA Source Classification Code - None
7. References -
(1) Development Document for Effluent Limitations Guidelines
and Standards of Performance, Mining and Ore Dressing
Industry, U. S. Environmental Protection Agency, (pre-
pared by Calspan Corp., Buffalo, N. Y.), April 1975.
(2) Private communication with members of the BCL staff who
have consulted with producers on energy requirements
and specifics of operation.
(3) Griffith, Robert F., Chapter on Vanadium. Mineral Facts
and Problems, 1970, Bureau of Mines Bulletin 650, Bureau
of Mines, U. S. Department of the Interior, po 417-430.
273
-------
VANADIUM - COMPLEX VANADIUM MINERAL DEPOSIT PROCESS NO. 2
Crushing, Drying, Screening, and Grinding
1. Function - Ore is crushed, dried, then ground and
classified by screening to minus 1.17 mm (-14 mesh)
in preparation for the next step in processing—mixing
with salt, and pelletizing. Crushed ore is dried in
a rotary kiln dryer which is equipped with a wet-scrubber.
2. Input Materials - Ore containing 1.5-2.0 percent VpO,-
from open-pit mine and water.
3. Operating Parameters -
Temperature: Roasting, 850C (1562)
Pressure: Atmospheric •
4. . Utilities -
Q
Electric Energy: 0.73 x 10 joules/metric ton (20.4
kWhe/metric ton or 0.19 x 106 Btu/short ton) of ore
Natural Gas: 9.4 cu meters/metric ton (302 cu ft/short
ton of ore
5. Waste Streams -
Dust, particulates in crushing and grinding
Bleed from wet scrubber on the rotary kiln dryer has a
pH of 7.8, a total dissolved solids (T.D.S.) content of
about 7500 mg/1, and a chloride content of about 4000 mg/1.
6. EPA Source Classification Code - None
7. References -
(1) Development Document for Effluent Limitations Guidelines
and Standards of Performance, Mining and Ore Dressing
Industry, U. S. Environmental Protection Agency, (pre-
pared by Calspan Corp., Buffalo, N. Y.), April 1975.
(2) Private communication with members of the BCL staff who
have consulted with producers on energy requirements and
specifics of operation.
274
-------
(3) Griffith, Robert F., Chapter on Vanadium, Mineral Facts
and Problems, 1970, Bureau of Mines Bulletin 650, Bureau
of Mines, U. S. Department of the Interior, pp 417-430.
275
-------
VANADIUM - COMPLEX VANADIUM MINERAL DEPOSIT PROCESS NO. 3
Hydrometallurgical Processing
1. Function - In the hydrometallurgical processing of ore to
vanadium pentoxide, the crushed and dried ore is ground and
screen classified to minus 1.17 mm (-14 mesh), and then mixed
with about 7 percent by weight of salt, following which it
is pelletized, and roasted at 850 C (1560 F) to convert
vanadium in the ore to soluble sodium vanadate, NaV03-
It is then quenched in water, after which the water
solution is acidified with sulfuric acid to a pH of
2.5-3.5. The resulting sodium decavanadate, Na5V]g028>
is concentrated by solvent extraction and in the process
freed of impurities such as sodium from the roasting
operation, and calcium, iron, phosphorous, and silica
from the ore; these impurities remain in the raffinate.
Slightly soluble ammonium vanadate, MH4V03, is precipitated
from the stripping solution with ammonia. The ammonium
vanadate is then calcined to yield vanadium pentoxide,
V2°5-
2. Input Materials - minus 1.17 mm (-14 mesh) ore; salt, from
6-10 percent by weight of ore; sulfuric acid (additions to
water solution of sodium vanadate to yield a pH range of
2.5 to 3.5); tertiary amines (solvent extraction) 0.61
Kg/metric ton (1.25 Ib/short ton) of ore (based on
analogous operation); ammonium hydroxide (additions to
precipitate' NfyVOs) 0.65 Kg/metric ton (1.30 Ib/short
ton) of ore (based on analogous operation)
3. Operating Parameters -
The temperature of the salt roast is 850 C (1560 F).
Quenching in water follows roasting. The pH of this water
leach containing vanadium as soluble sodium decavanadate
Na6V10028, is adjusted to 2.5-3.5 with ^$04 additions.
Vanadium in this solution is then further concentrated
by solvent extraction. Stripped liquor from this
operation is heated and the pH adjusted with ammonia to
convert the sodium decavanadate Na5V-|Q028 to ammonium
vanadate, (Nfy ^40-12- The solution is cooled, fed to
continuous cooling crystalizers which crystallize out
ammonium vanadate.
276
-------
4. Utilities -. (based on analogous operation)
Electric energy: for salt roasting, 0.049 x 108 joules/
metric ton (1.35 kWhe/metric ton or 0.013 x 10° Btu/
short ton) of ore; for leaching; 0.049 x 10° joules/
metric ton (1.35 kWhe/metric ton or 0.013 x 10° Btu/
short ton) of ore; for solvent extraction, 0.049 x
10a joules/metric ton (1.35 kWhe/metric ton or 0.013
x 106 Btu/short ton) of ore; for precipitation and
calcining, 0.011 x 10° joules/metric ton (0.3 kWhe/
metric ton or 0.003 x 105 Btu/short ton) of ore
Natural Gas: for salt roasting, 67 cu meters/metric
ton (2140 cu ft/short ton) of ore; for leaching, 3.9
cu meters/metric ton (124 cu ft/short ton) of ore;
for solvent extraction, 8.4 cu meters/metric ton
(268 cu ft/short ton) of ore; for precipitation and
calcining, 11 cu meters/metric ton (354 cu ft/short
ton) of ore
5. Waste Streams -
Stack exhausts from rotary kiln drying and roasting cycles
are cleaned with wet scrubbers.
Effluent streams from leaching and solvent extraction are sent
to tailing ponds where "brown mud" waste material from nearby
alumina plants may be used to clarify the waste water before
it is discharged to streams.
Streams from leaching, solvent extraction, and wet scrubbers on
the dryer and salt roast operations account for 70 percent of
the effluent streams.
The leach and solvent extraction effluent (pH, 3.5) contains
extremely high amounts of dissolved sulfate, 26,000 ma/1. The
chloride content is also appreciable, 7,900 mg/1.
The salt roast scrubber bleed (pH, 2.5) contains extremely high
amounts of calcium (78,000 mg/1) and chloride (about 60,000 mg/1.
Effluents from the leach and solvent extraction plant (T.D.S.,
about 40,000 mg/liter) and the salt roast scrubber bleed (T.D.S.,
about 50,000 mg/liter) are segregated in the plant to avoid
the generation of voluminous calcium sulfate precipitates. They
are discharged into tailing pond at the same point after being
diluted 10:1 just before discharge. Discharges from the tailing
pond to area streams are made only during wet seasons. The major
emission associated with calcining is high nitrogen (thousands of
ppm) in the effluent from the wet scrubber.
277
-------
6. EPA Source Classification Code - None
7. References -
(1) Development Document for Effluent Limitations Guidelines
and Standards of Performance, Mining and Ore Dressing
Industry, U. S. Environmental Protection Agency (pre-
pared by Calspan Corp., Buffalo, N. Y.), April 1975.
(2) Private communication with members of the BCL staff who
have consulted with producers on energy requirements
and specifics of operation.
(3) Griffith, Robert F., Chapter on Vanadium, Mineral Facts
and Problems, 1970, Bureau of Mines Bulletin 650, Bureau
of Mines, U. S. Department of the Interior, pp 417-430.
278
-------
APPENDIX A
Population of U.S. Metal-Mining
and Beneficiation Companies
-------
APPENDIX A
Population of U.S. Metal Mining
and Beneficiation Companies
Bauxite Mining and Beneficiating Companies
(1) General Refractories Company
(Southern Mines)
Stevens Pottery
Georgia 31088
(2) Eufaula Bauxite Mining Company
P. 0. Box 556
Eufaula, Alabama 36027
(3) A. P. Green Refractories
Eufaula
Alabama 36027
(4) Harbison-Walker Refractories
Company, Div. of Dresser
Industries, Inc.
Eufaula, Alabama 36027
(5) Wilson-Sneed Mining Co., Inc.
P. 0. Box 568
Eufaula, Alabama 36027
(6) Aluminum Company of America
P. 0. Box 300
Bauxite, Arkansas 72011
(7) American Cyanamid Company
Industrial Chemicals and
Plastics Division
P. 0. Box 246
Benton, Arkansas 72015
(8) Englehard Minerals & Chemicals
Corporation
Minerals and Chemicals Div.
Little Rock, Arkansas 77206
(9) Reynolds Mining Corporation
P. 0. Box 398
Bauxite, Arkansas 72011
(10) Stauffer Chemical Company
Industrial Chemical Division
P. 0. Box 188
North Little Rock, Arkansas
72115
A-l
-------
Antimony Ore Producers
(1) U.S. Antimony Corporation (Babbit Mine)
P.O. Box 643
Thompson Falls, Montana 59873
(2) Hecla Mining Company (Consolidated Silver Project)
P.O. Box 259
Osburn, Idaho 83849
(3) Sunshine Mining Company (Sunshine Mine)
P.O. Box 1080
Kellogg, Idaho 83837
A-2
-------
Beryllium Ore Producers
(1) Brush Wellman, Inc.
(Spor Mountain Operations)
P. 0. Box
Delta, Utah
(2) U. S. Beryllium Corporation
303 Bon Durant Building
Pueblo, Colorado 81003
(3) Jack Pendleton
Custer
South Dakota 57730
(4) John Carter
608 St. Cloud Avenue
Rapid City, South Dakota 57701
A-3
-------
Columbiurn-Tantalum Ore Producers
(1) Curtis Nevada Mines, Inc.
P.O. Box 133
Topaz, California 96133
Raw Materials
The minerals of importance for the production of columbiurn and tantalum
are columbite, (Fe,Mn)(Cb,Ta)205; tantalite, (Fe,Mn) (Ta.CbUOg;
pyrochlore, NaCaCboOgF; and several complex rare earth-content minerals
such as euxenite, fCe,YJTh,Ca,U)(Cb,Ta,Ti)206.
Columbite and tantalite are actually a series of oxide mixtures includ-
ing oxides of iron and manganese in chemical bond wherein the mineral
is termed columbite when the amount of columbium (niobium) is high, and
tantalite when more tantalum than columbium is present. As mentioned
previously, columbite-tantalite mineralization is commonly of pegmatitic
occurrence (or in placers derived from pegmatite weathering). The min-
eralization of the ore being mined in California includes columbite,
tantalite, yttrocerite and sarnarskite (rare earth minerals), siserskite
(platinum metals group), and the noble metals, gold and silver.
Columbiurn-Tantalum Products
The products resulting from the mining and beneficiating of ores for
the production of columbium and tantalumin the U.S. are the concen-
trates of the appropriate minerals, columbite and tantalite.
A-4
-------
Copper Mining and Beneficiating Companies
(1) American Smelting and Refining
Company
San Xavier Unit
P. 0. Box 111
Sahuarita, Arizona 85629
(2) American Smelting and Refining
Company
Sacation Unit
P. 0. Box V
Casa Grande, Ari'zona 85222
(3) American Smelting and Refining
Company
Mission Unit
P. 0. Box 111
Sahuarita, Arizona 85629
(4) American Smelting and Refining
Company
Silver Bell Unit
Silver Bell, Arizona 85270
(5) The Anaconda Company
Primary Metals Division
Butte Operations
P. 0. Box 1971
Butte, Montana 59701
(6) The Anaconda Company
Primary Metals Division
Yerington Mines
P. 0/Box 1000
Weed Heights, Nevada 89443
(7) APCO Oil Corporation
Minerals Division
Cove Meadow Copper Mine
P. 0. Box 6
Wadsworth, Nevada 89442
(8) Anamax Mining Company
Twin Buttes Operation
P. 0. Box 127
Suharita, Arizona 85629
(9) Cities Service Company
North American Chemicals
& Metals Group
Miami Copper Operations
P. 0. Box 100
Miami, Arizona 85539
(10) Cities Service Company
North American Chemicals
& Metals Group
Pinto Valley'Operations
P. 0. Box 727
Miami, Arizona 85539
(11) Cities Service Company
North American Chemicals
& Metals Group
Copperhill Operations
Copperhill, Tennessee 37317
(12) Cobre Mines,
Cobre Mine
Box 378
Hanover, New
Inc.
Mexico 88041
(13) Continental Copper, Inc.
Control Mine
P. 0. Box 622
Oracle, Arizona 85623
(14) Cyprus Mines Corporation
Bruce Mine Division
P. 0. Box 457
Bagdad, Arizona 86321
A-5
-------
(15) Duval Corporation
Mineral Park Property
P. 0. Box 1271
Kingman, Arizona 86401
(16) Duval Corporation
Esperanza Property
P. 0. Box 38
Sahuarita, Arizona 85629
(17) Duval Sierrita Corporation
Sierrita Property
P. 0. Box 125
Sahuarita, Arizona 85629
(18) Eagle-Pilcher Industries, Inc.
Creta Operation
P. 0. Box 16
Olustee, Oklahoma 73560
(19) Earth Resources Company
Nacimiento Copper Mine
P. 0. Box 202
Cuba, New Mexico 87013
(20) El Paso Natural Gas Company
Emerald Isle Plant
P. 0. Box 1313
Kingman, Arizona 86401
(21) Federal Resources Corporation
Bonney-Miser's Chest and
'85' Mines •
P. 0. Box A
Lordsburg, New Mexico 88045
(22) Goldfield Corporation
San Pedro Copper Mine
101, 65 East Nasa Boulevard
Melbourne, Florida 32901
(23) Hecla Mining Company
Lakeshore Copper Property
P. 0. Box 493
Casa Grande, Arizona 85222
(24) Homestake Copper Company
650 California Street
San Francisco, California
54108
(25) Imperial Consolidated
Copper Company
Ox Hide Mine
Inspiration, Arizona 85537
(26) Inspiration Consolidated
Copper Company
Christmas Division
Inspiration, Arizona 85537
(27) Inspiration Consolidated
Copper Company
Sanchez Project
Inspiration, Arizona 85537
(28) Inspiration Consolidated
Copper Company
Inspiration Division
Inspiration, Arizona 85537
(29) Imperial Copper Company
11634 Davis Street
Sunnymead, California 92388
(30) Kennecott Copper Corporation
Ray Mines Division
Hayden, Arizona 85235
(31) Kennecott Copper Corporation
Utah Copper Division
P. 0. Box 11299
Salt Lake City, Utah 84111
(32) Kennecott Copper Corporation
Chi no Mines Division
Hurley, New Mexico 88043
(33) Kennecott Copper Corporation
Nevada Mines Division
McGill, Nevada 89313
A-6
-------
(34) Kerramerican, Inc.
Blue Hill Mine
P. 0. Box D
Blue Hill, Maine 04614
(35) Keystone Wallace Resources
702 South Main Street
Moab, Utah 84532
(36) Magma Copper Company
San Manuel Division
P. 0. Box M
San Manuel, Arizona 85631
(37) Magma Copper Company
Superior Division
Box 37
Superior, Arizona 85273
(38) McAlester Fuel Company
Zonia Operation
Route 1
Kirkland, Arizona 86332
(39) Micro Copper Corporation
Lisbon Valley Mine
Uranium Building
Moab, Utah 84532
(40) Phelps Dodge Corporation
Tyrone Branch
Tyrone, New Mexico 88065
(41) Phelps Dodge Corporation
Copper Queen Branch
Bisbee, Arizona 85603
(42) Phelps Dodge Corporation
Morenci Branch
Morenci, Arizona 85540
(43) Phelps Dodge Corporation
New Cornelia Branch
Ajo, Arizona 85321
(44) Pima Mining Company
Box 7187
Tucson, Arizona 85725
(45) Ranchers Exploration &
Development Corporation
Big Mike Mine
620 Metaky Street
Winnemucca, Nevada 89445
(46) Ranchers Exploration &
Development Corporation
Ranchers Bluebird Mine
Box 880
Miami , Arizona
(47) Ranchers Exploration &
Development Corporation
Old Reliable Mine'
149 Main Street
Mammoth, Arizona
(48) Salmon Canyon Copper Co.
P. 0. Box 891
Jamestown, North Dakota
58401
(49) Toledo Mining Company
OK Mine
323 Newhouse Building
Salt Lake City, Utah 84111
(50) USNR Mining & Minerals Inc.
Copper Leach Mine
P. 0. Box 1256
. Silver City, New Mexico
88061
(51) White Pine Copper Company
White Pine
Michigan 49971
A-7
-------
Gold Ore Processing Companies
(1) APCO Oil Corporation
Minerals Division
P. 0. Box 51
Downieville, California 95935
(2) APCO Agricola Mines
Independence Mine
P. 0. Box 397
Battle Mountain, Nevada 85820
(3) Carl in Gold Mining Company
P. 0. Box 973
Carl in, Nevada 89822
(4) Coronado Silver Corporation
Los Lagos Office
Rollinsvilie, Colorado 80474
(5) Cortez Gold Mines
Cortez
Nevada 89821
(6) Homestake Mining Company
P. 0. Box 875
Lead, South Dakota. 57754
(7) Inland Empire Milling &
Mining Corporation
432 North "G" Street
San Bernardino, California
92410
(8) L & K Development Corporation
3450 Glen Avenue
Oroville, California 95965
(9) The Old Ontario Mining Company
P. 0. Box 93
Duncan, Arizona 85534
(10) Picacho Development Corp.
c/o Continental Diversified
Industries, Inc.
433 Maple Avenue
Westbury, New York 11590
(11) Sultan Sawmill & Mining Co.
1808 8th Avenue
Seattle, Washington 98101
(12) United States Platinum Inc.
2301 Oddie Blvd., #123
Reno, Nevada 89503
(13) U. V. Industries, Inc.
P. 0. Box 1170
Fairbanks, Alaska 99701
A-8
-------
Iron Ore Processing Companies
(1) Adams Mine
The Cleveland-Cliffs Iron
Company
Kirkland Lake
Ontario, Canada
(2) Bethlehem Mines Corporation
Bethlehem
Pennsylvania 18016
(3) Butler Taconite
The Hanna Mining Company
Cooley, Minnesota
(4) Caland Ore Company Ltd.
Inland SteeT Company
Atikokan
Ontario, Canada
(5) Cities Service Company
Copperhill Operations
Copperhill, Tennessee 37317
(6) The Cleveland-Cliffs Iron
.Company
1460 Union Commerce Building
Cleveland, Ohio 44115
(7) Coons Pacific Company
2521 First Avenue
Hibbing, Minnesota 55746
(8) Empire Iron Mining Company
The Cleveland-Cliffs Iron
Company
Eagle Mills, Michigan
(9) Erie Mining Company
Pickands Mather & Co.
P. 0. Box 847
Hoyt Lakes, Minnesota
55750
(10) Eveleth Taconite Company
Oglebay Norton Company
Thunderbird, Minnesota
(11) Hanna Iron Ore Division
National Steel Corporation
100 Erieview Plaza
Cleveland, Ohio 44114
(12) The Hanna Mining Company
100 Erieview Plaza
Cleveland, Ohio 44114
(13) Inland Steel Company
30 West Monroe Street
Chicago, Illinois 60603
(14) Jackson County Iron Co.
Inland Steel Company
Black River Falls
Wisconsin
(15) Jones & Laughlin Steel Corp.
3 Gateway Center
Pittsburgh, Pennsylvania
15230
(16) Kaiser Steel Corporation
Kaiser Center
300 Lakeside Drive
Oakland, California 94612
(17) Lone Star Steel Company
P. 0. Box 35888
2200 West Mockingbird Lane
Dallas, Texas 75235
(18) Luck Mining Company
215 Market Street, Room 810
San Francisco, California
94105
A-9
-------
(19) Marquette Iron Mining Co.
The Cleveland-Cliffs Iron
Company
Humboldt, Michigan
(20) Meramec Mining Company
250 Park Avenue
• New York, New York 10017
(21) The Mesaba-Cliffs Mining
Company
The Cleveland-Cliffs Iron
Company
Coleraine, Minnesota
(22) N L Industries, Inc.
Titanium Pigment Div. (USTP)
100 Chevalier Avenue
South Amboy, New Jersey
08879
(23) The Negaunee Mine Company
The Cleveland-Cliffs Iron
Company
Negaunee, Michigan
(24) Nevada-Barth Corporation
P. 0. Box 1057
Winnemucca, Nevada 89445
(25) Oglebay Norton Company
1200 Hanna Building
Cleveland, Ohio 44115
(26) Pacific Isle Mining Company
Inland Steel Company
Ishpeming, Michigan 49849
(27) Pickands Mather & Co.
1100 Superior Avenue
Cleveland, Ohio 44114
(28) Pilot Knob Pellet Company
The Hanna Mining Company
.. Pilot Knob, Missouri
(29) Pioneer Pellet Plant
The Cleveland-Cliffs Iron
Company
Eagle Mills, Michigan
(30) Pittsburgh Pacific Company
2521 First Avenue
Hibbing, Minnesota 55746
(31) Reserve Mining Company
Silver Bay
Minnesota 55614
(32) Rhude & Fryberger, Inc.
P. 0. Box 66
Hibbing, Minnesota 55746
(33) Sherman Mine
The Cleveland-Cliffs Iron
Company
Temagami, Ontario
Canada
(34) The Standard Slag Company
1200 Stambaugh Building
Youngstown, Ohio 44501
(35) Tex-Iron, Inc.
P. 0. Box 367
Gushing, Texas
75760
(36) Til den Mining Company
The Cleveland-Cliffs Iron
Company
Til den Township
Michigan
(37) United States Pipe and
Foundry Company
3300 First Avenue, North
Birmingham, Alabama 35202
A-10
-------
(38) United States Steel Corp.
600 Grant Street
Pittsburgh, Pennsylvania
15230
(39) Utah International Inc.
550 California Street
San Francisco, California
94104
(40) CF & I Steel Corporation
Sunrise Mine
P. 0. Box 457
Guernsey, Wyoming 82214
(41) CF & I Steel Corporation
Cornstock Mine
P. 0. Box 100
Center City, Utah 84720
(42) Cranberry Magnetite Corp.
Greenback Industries, Inc.
P. 0. Box 63
Greenback, Tennessee 37742
(43) Cranberry Magnetite Corp.
Greenback Industries, Inc.
Cranberry, North Carolina
28614
(44) Dunbar Layton Mining
P. 0. Box 267
Lumpkin, Georgia 31815
(45) Glenwood Mining Company
Glenwood
Alabama 36034
(46) Halecrest Company, Inc.
Talmadge Road
Edison, New Jersey 08817
(47) Halecrest Company, Inc.
Mt. Hope Iron Mine
RD No. 1
Wharton, New Jersey 07885
(48) Leber Mining Company
Falcon Mine
Stamps, Arkansas 71860
(49) Mahoning Ore & Steel Company
Mahoning Mine
Box 308
Kelly Lake, Minnesota 55754
(50) Shook & Fletcher Supply Co.
1814 First Avenue North
Birmingham, Alabama 35202
(51) J. R. Simplot Company
Simplot Iron Mines
Palisades Nevada
(52) Snyder Mining Company
Div. Shenango Furnace Company
Whiteside Mine
Box 218
Buhl, Minnesota 55713
(53) Republic Steel Corporation
Adirondack Ore Mines
Mineville, New York 12956
A-ll
-------
Lead-Zinc Ore Processing Companies
(Lead Predominating)
(1) Allied Chemical Corporation
Industrial Chemicals Div.
P. 0. Box 228
Boulder, Colorado 80302
(2) AMAX Lead and Zinc, Inc.
Buick Mine
Boss, Missouri 65440
(3) AMAX Lead and Zinc, Inc.
7733 Forsyth Boulevard
Clayton, Missouri 63105
(4) American Smelting &
Refining Co.
Leadville Unit
Box 936
Leadville, Colorado 80461
(5) The Bunker Hill Company
P. 0. Box 29
Kellogg, Idaho 83837
(6) Camp Bird Colorado, Inc.
Duray
Colorado 81427
(7) Cominco American Incorporated
Magmont Mine
Bixby, Missouri 65439
(8) Day Mines, Inc.
506-1/2 Cedar Street
Wallace, Idaho 83873
(9) Kennecott Copper Corporation
Tintic Division
P. 0. Box 250
Eureka, Utah 84628
(10) Ozark Lead Company
Rural Branch
Sweetwater, Missouri
63680
(11) Pend Oreille Mines & Metals
Company
923 Old National Bank Bldg.
Spokane, Washington 99201
(12) Pend Oreille Mines & Metals
Company
Metaline Falls
Washington 99153
(13) Rico Argentine Mining Co.
Rico
Colorado 81332
(14) St. Joe Minerals Corporation
250 Park Avenue
New York, New York 10017
(15) St. Joe Minerals Corporation
Edwards Mine
Balmat, New York 13609
(16) St. Joe Minerals Corporation
Fletcher Mine
Bonne Terre, Missouri 63628
(17) St. Joe Minerals Corporation
Brushy Creek
Bonne Terre, Missouri 63628
(18) St. Joe Minerals Corporation
Indian Creek
Bonne Terre, Missouri 63628
(19) St. Joe Minerals Corporation
Viburnam
Bonne Terre, Missouri 63628
A-12
-------
Zinc-Lead Ore Processing Companies
(Zinc Predominating)
(1) American Smelting & Refining
Refining Company
Mascot Operations
Mascot, Tennessee 37806
(2) American Smelting &
Refining Company
New Market Mine
P. 0. Box 66
New Market, Tennessee
37820
(3) American Smelting .&
Refining Company
Deming Mill
P. 0. Box 1037
Deming, New Mexico 88030
(4) American Smelting &
Refining Company
Ground Hog Unit
P. 0. Box 186
Vanadium, New Mexico 88073
(5) Cerro Spar Corporation
P. 0. Box 213
Salem, Kentucky 42078
(6) Eagle-Picher Industries Inc.
Metal Mining Department
Illinois-Wisconsin Operation
P. 0. Box 1040
Galena, Illinois 61036
(7) Hecla Mining Company
Hecla Building
Wallace, Idaho 83873
(8) Hydro Nuclear Corporation
Suite 700
First National Bank Bldg. E.
Albuquerque, New Mexico 87108
(9) Idarado Mining Company
Ouray
Colorado 81427
(10) Ivey Construction Company
128 High Street
Mineral Point, Wisconsin
53565
(11) Minerva Oil Company
Fluorspar Division
P. 0. Box 531
Eldorado, Illinois 62930
(12) The New Jersey Zinc Company
Austinville Mine
Austinville, Virginia 24212
(13) The New Jersey Zinc Company
Friedenville Mine
R. D. 1
Center Valley, Pennsylvania
18034
(14) The New Jersey Zinc Company
Sterling Mine
Plant Street
Ogdensburg, New Jersey 07439
(15) The New Jersey Zinc Comoanv
Jefferson City Mine
P. 0. Box 32
Jefferson City, Tennessee
37760
A-13
-------
(16) The New Jersey Zinc Company
Gil man Mine
P. 0. Box 118
Gil man, Colorado 81634
(17) Ozark Mahoning Company
Johnson Works
Rosiclare, Illinois 62982
(18) Resurrection Mining Company
Leadville
Colorado
(19) E. G. Sommerlath Enterprises
33740 Lindell Boulevard
Marion, Kentucky 42064
(20) Standard Metals Corporation
Silverton Operations
P. 0. B x 247
Silverton, Colorado 81423
(21) United States Steel Corp.
Zinc Mine
Jefferson City, Tennessee
37760
(22) U. V. Industries, Inc.
Bullfrog Mill
P. 0. Box 406
Hanover, New Mexico
88041
(23) U. V. Industries, Inc.
Hanover Mine
P. 0. Box 406
Hanover, New Mexico
88041
(24) U. V. Industries, Inc.
Princess Mine
P. 0. Box 406
Hanover, New Mexico
88041
A-14
-------
Manganese-Content Ore Producers
(1) Hanna Mining Company
Lauretta Manganiferous
Mine Project
Crosby, Minnesota 56441
(2) Luck Mining Company
P. 0. Box 29
Silver City, New Mexico
88061
(3) The New Jersey Zinc Company
Sterling Mine
Plant Street
Ogdensburg, New Jersey
07439
Raw Materials
Manganese occurs in a great many minerals that are widely distributed
in the earth's crust. Commercially, the most important minerals are
the oxides, manganite (Mn20o-H20), and pyrolusite (MnC^). World produc-
tion outside the U. S. is almost entirely from oxides. In the U. S.,
the oxide minerals are found with the carbonate mineral rhodocrosite
(MnCOg), as at Butte, Montana, in small quantities. The manganese
oxides predominate in the Minnesota Cuyuna Range ore which contains
13.75 percent manganese as mined. Presumably the oxides also are the
prevalent form of manganese in the New Mexico mine recovery of mangani-
ferous iron ore. The manganese minerals in the New Jersey zinc recovery
operations have not been identified.
Manganese Ore Products
As previously indicated, manganese is recovered in the form of man-
ganiferous iron ore concentrate from the Minnesota and New Mexico
mining operations and as ferromanganese alloy from the smelting of
the New Jersey zinc ore (the zinc ore is smelted in Pennsylvania).
The latter product is designated as manganese-in-residue on the lead-
zinc process flow diagram.
A-15
-------
Mercury Producers
(1) Buena Vist Mines, Inc.
1140 Railroad Street
P. 0. Box 753
Paso Robles, California
93446
(2) El Paso Natural Gas Co.,
Mining Division
P. 0. Box 627
Weiser, Idaho 83672
(3) New Idria Mining and
Chemical Company
21731 Almaden Road
San Jose, California
95120
(4) New Idria Mining and
Chemical Company
Idria Mine
Idria, California 95027
(5) New Idria Mining and
Chemical Company
New Almaden Mine
P. 0. Box 68
Almaden, California 95042
(6) New Idria Mining and
Chemical Company
Old Guadalupe Mine
18501 Hicks Road
Los Gatos, California
95120
(7) Superior Gypsum Company
2150 Franklin Street
Oakland, California
94612
(8) Superior Gypsum Company
Petaluma Mine
Petaluma, California 94952
A-16
-------
Molybdenum Ore Processing Companies
(1) Climax Molybdenum Company
Div., AMAX
Western Operations Hqs.
Mines Park
Golden, Colorado 80401
(2) Climax Molybdenum Company
Climax Mine
Climax, Colorado 80429
(3) Climax Molybdenum Company
Henderson Mine
P. 0. Box 63 (Georgetown)
Empire, Colorado 80438
(4) Molybdenum Corporation of America
Questa Mine
Questa, New Mexico 87556
A-17
-------
Nickel Ore Producers
(1) The Hanna Mining Company and
The Hanna Nickel Smelting Company
Riddle, Oregon 97469
A-18
-------
Platinum Concentrate Producers
(1) Goodnews Bay Mining Company
Platinum
Alaska 99651
(2) United States Platinum Milling, Incorporated
P. 0. Box 481
Bridgeport, California 93517
A-19
-------
Rare Earth Metals Ore Producers
(1) Curtis Nevada Mills, Inc.
P. 0. Box 133
Rickey Canyon, California
(2) Molybdenum Corporation of America
Nipton
California 92366
A-20
-------
Silver Ore Processing Companies
(1) American Smelting and
Refining Company
Galena Unit
P. 0. Box 440
Wallace, Idaho 83873
(2) Black & White Mining Co.
4207 21st Avenue
Missoula, Montana 59801
(3) Black & White Mining Company
Brooklyn Mine
Maxville, Montana 59801
(4) Bunker Hill Company
Crescent Mine
P. 0. Box 29
Kellogg, Idaho 83837
(5) Clayton Silver Mines
P. 0. Box 890
Wallace, Idaho 83873
(6) Hecla Mining Company
Consolidated Silver Project
P. 0. Box 259
Osburn, Idaho 83849
(7) Hecla Mining Company
Lucky Friday Mine
Mull an, Idaho 83846
(8) Homestake Mining Company
Bulldog Mountain Project
P. 0. Box 98
Creede, Colorado 81130
(9) McFarland & Hullinger
915 North Main Street
Tooele, Utah 84074
(10) McFarland & Hullinger
Ophir Mine
Ophir, Utah 84056
(11) Minerals Engineering Company
Creede Associates, Ltd.
P. 0. Box 377
Creede, Colorado 81130
(12) Montecito Minerals Company
1482 East Valley Road
Santa Barbara, California
93108
(13) Nancy Lee Mines, Inc.
P. 0. Box 67
Kellogg, Idaho 83837
(14) Sierra Silver Lead Mining Co.
46 East Thirtieth Avenue
Spokane, Washington 99203
(15) Standard Resources, Inc.
P. 0. Box 1106
Carson City, Nevada 89701
(16) Sunshine Mining Company
Sunshine Mine
P. 0. Box 1080
Kellogg, Idaho 83837
(17) Sunshine Mining Company
Sixteen-to-One Mine
Silver Peak, Nevada 89047
(18) Universal Exploration, Inc.
Silver Moon Mine
3935 North Yellowstone
Idaho Falls, Idaho 83401
A-21
-------
Thorium Ore Producers
(1) E. I. du Pont de Nemours
& Company, Inc.
(Clay County) Florida
(2) Humphreys Mining Company
(Char!ton County) Georgia
(3) Titanium Enterprises, Inc.
(Clay County) Florida
(4) Climax Molybdenum Company
Leadville
Colorado
(5) Kendrick Bay Mining Company
Prince of Wales Island County
Alaska
Raw Materials
The occurrence of thorium is widespread, and large deposits are found in
beach and fluviatile placers, veins, sedimentary rocks, alkalic igneous
rocks, and carbonatites. The principal minerals recovered for thorium
extraction are monazite, (Ce,La,Th)P04; thorite, ThSiC^; multiple oxide
minerals of Ti ,U,Ca,Fe,Th, and Y, such as brannerite; and thorianite,
Th02- Important thorium contents are present in some uranium ores but
not in most of the U. S. uranium ores. The amount of thorium present
in our stateside uranium ores is generally too small for economic recovery.
An Alaskan uranium mine does recover thorium as a by-product, however.
Thus, the domestic source for thorium is principally monazite as pre-
viously described—a by-product in titanium and molybdenum ore recovery
operations. While the ThC^ content of monazite may range between 0 and
32 percent, the domestic monazite contains .from about 3.5 to 9 percent
ThCL, with a 5 percent average over several years from all production.
A-22
-------
Thorium Ore Products
Monazite concentrates (imported concentrates are processed as well as
domestically produced concentrates) are treated chemically to recover
the rare earth-oxide content. In the chemical plants, thorium phos-
phate precipitate is recovered in one process. Another process
results in a hydroxide residue. These compounds can be purified by
solvent extraction techniques and ultimately high purity thorium
nitrate, thorium oxide, or other thorium compounds can be obtained
chemically. Metallic thorium can be produced by reduction of the
halides with calcium or magnesium, fused-salt electrolysis, or by
other methods, all of which require a high technology for the produc-
tion of pure metal.
A-23
-------
Tin Concentrate Producers
(1) Climax Molybdenum Company
Division of AMAX
Western Operations Hqs.
Mines Park
Golden, Colorado 80401
(2) Climax Molybdenum Company
Climax Mine
Climax, Colorado 80429
Raw Materials
The tin-containing mineral of worldwide economic importance is
cassiterite, Sn02-
Tin Products
A small amount, of tin reports along with the tungsten and other
non-molybdenum minerals in the tailings from the molybdenum
mining operations in Colorado. These non-molybdenum minerals
are concentrated and separated from one another in a gravity-
flotation process. The tin mineral concentrate is finally
separated from tungsten concentrate by magnetic separation as
indicated in the flow diagram for molybdenum.
A-24
-------
Titanium Ore Processing Companies
(1) American Smelting and
Refining Company
Oak Tree Road and
Park Avenue
South Plainfield,
New Jersey 07080
(2) E. I. du Pont de Nemours
& Company, Inc.
Highland Plant
P/0. Box 68
Lawtey, Florida 32092
(3) E. I. du Pont de Nemours
& Company, Inc.
Trail Ridge Plant
P. 0. Box 753
Starke, Florida 32091
(4) The Feldspar Corporation
P. 0. Box 69
Middletown, Connecticut
06453
(5) Glidden-Durkee Division
SCM Corporation
P. 0. Box 5
Lakehurst, New Jersey
08733
(6) National Lead Industries,
Incorporated
111 Broadway
New York, New York 10006
(7) The Feldspar Corporation
Rt. 1, P. 0. Box 23
Montpelier, Virginia
23192
(8)
Humphreys
P. 0. Box
Folkston,
Mining Company
8
Georgia 31537
(9) Titanium Enterprises,
Green Cove Springs
Florida
Inc.
A-25
-------
Tungsten Ore Processing Companies
(1) Comeback Consolidated Inc.
Placerville
California
(2) Henry C. & John Crofoot
P. 0. Box 797
Lovelock, Nevada 89419
(3) General Electric Company
Minerals Engineering Company
Dillon, Montana
(4) General Electric Company
Minerals Engineering Company
Avron, Montana
(5) General Electric Company
Minerals Engineering Company
White Pine County, Nevada
(6) Las Maderas Mining and
Petroleum, Ltd.
Fresno
California
(7) Mines Exploration, Inc.
P. O.'Box 27
Red Mountain, California
92374
(8) Montecito Minerals Company
1482 East Valley Road
Santa Barbara, California
93108
(9) Montecito Minerals Company
P. 0. Box 125
Darwin, California 93522
(10) Frank Ramsey
3445 Court Street
Baker, Oregon 97814
(11) Rawhide Mining Company
Rawhide
Nevada
(12) Tungsten Properties, Ltd.
P. 0. Box A
Inlay, Nevada 98418
(13) Union Carbide Corporation
Mining & Metals Division
270 Park Avenue
New York, New York 10017
(14) Union Carbide Corporation
Pine Creek Mine and Mill
Bishop, California 93514
A-26
-------
Uranium Ore Producers
(1) Altamont Uranium and
Mining Company, Inc.
P. 0. Box 1776
Salt Lake City, Utah
84110
(2) The Anaconda Company
Jackpile-Paguate Mine
P. 0. Box 638
Grants, New Mexico 87020
(3) Atlas Minerals Division
Atlas Corporation
Big Indian Mines
P. 0. Box 1207
Moab, Utah 84532
(4) Atlas Minerals Division
Atlas Corporation
Moab Mill
P. 0. Box 1207
Moab, Utah 84532
(5) Blake Mining Company
Box 431
Nucla, Colorado 81424
(6) Continental Oil Co., Inc.
Conquista Project
P. 0. Box 300
Falls City, Texas 78113
(7) Continental Uranium Company
of Wyoming
Box 662
Oracle, Arizona 85623
(8) Dawn Mining Company
P. 0. Box 25
Ford, Washington 99013
(9) Exxon Company, USA
Exxon Corporation
P. 0. Box 3020
Casper, Wyoming 82601
(10) Exxon Company, USA
P. 0. Box 2180
Houston, Texas 77001
(11) Federal-American Partners
520 East Main
Riverton, Wyoming 82501
(12) Four Corners Exploration Co.
Box 116
Grants, New Mexico 87020
(13) Homestake Mining Company
P. 0. Box 77
Grants, New Mexico 87020
(14) Kendrick Bay Mining Company
Prince of Wales Island County
Alaska
(15) Kerr-McGee Corporation
P. 0. Box 218
Grants, New Mexico
(16) Kerr-McGee Corporation
P. 0. Box 2855
Casper, Wyoming 82601
(17) Mines Development, Inc.
P. 0. Box 49
Edgemont, South Dakota 57735
(18) Mountain West Mines, Inc.
P. 0. Box 126
Blanding, Utah 84511
A-27
-------
(19) Petrotomics Company &
KGS--JV
P. 0. Drawer 2459
Casper, Wyoming 82601
(20) Ranchers Exploration &
Development Corporation
1776 Montano Road, N.W.
Albuquerque, New Mexico
87107
(21) Ranchers Exploration &
Development Corporation
P. .0. Box 2737
Grants, New Mexico 87020
(22) Rio Algom Corporation
P. 0. Box 610
Moab, Utah 84532
(23) Susquehanna Western, Inc.
Box 217
Falls City, Texas 78113
(24) Operations #2
Box 767
Three Rivers, Texas 78071
(25) Union Carbide Corporation
Mining & Metals Division
Grand Junction, Colorado
81501
(26) Union Carbide
Rifle Plant
Box 832
Rifle, Colorado 81650
(27) Union Carbide
Uravan Plant
Uravan, Colorado 81346
(28) Union Carbide Corporation
Mining & Metals Division
Gas Hills Station
Box 1500
Riverton, Wyoming 82501
(29) United Nuclear Corporation
Mining & Milling Division
P. 0. Box 3951
Albuquerque, New Mexico 87110
(30) United Nuclear Corporation
Ambrosia Lake Operation
P. 0. Box 199
Grants, New Mexico 87020
(31) United Nuclear-Homestake'
Partners
P. 0. Box 98
Grants, New Mexico 87020
(32) Utah International, Inc.
Shirley Basin Mine
Shirley Basin, Wyoming 82061
(33) Utah International, Inc.
Lucky Me Mine
P. 0. Box 831
Riverton, Wyoming 82501
(34) Western
Jeffrey
Jeffrey
Nuclear, Inc.
City Operations
City, Wyoming 82219
(35) Western Nuclear, Inc.
Rox Operations
254 North Center Street
Casper, Wyoming
A-28
-------
Vanadium Ore Producers
(1) Union Carbide Corporation
Route 6
P. 0. Box 943
Hot Springs, Arkansas 71901
(2) Kerr-McGee Chemical Corporation
Soda Springs Plant
P. 0. Box 478
Soda Springs, Idaho 83276
A-29
-------
Zirconium Ore Producers
.(1) E. I. du Pont de Nemours
& Company, Inc.
Highland Plant
P. 0. Box 68
Lawtey, Florida 32092
(2) E. I. du Pon.t de Nemours
& Company, Inc.
Trail Ridge Plant
P. 0. Box 753
Starke, Florida 32091
(3) Humphreys Mining Company
Folkston Plant
P. 0. Box 8
Folkston, Georgia 31537
(4) Titanium Enterprises,
Green Cove Springs
Florida
Inc.
Raw Materials
Both of the principal zirconium minerals, zircon (ZrSiO^ and
baddeleyite (ZrQo), occur as primary constituents in alkaline-rich
igneous rocks. The occurrence of these minerals in this mode is
widespread but there are no richly concentrated igneous rock
deposits of either mineral known in the U. S. The anciently
formed placer deposits along the Eastern seacoast, derived from
igneous rock masses, contain much more zircon than baddeleyite
and are the only current source of zirconium ore in the U. S.
Zirconium Products
The product resulting from the U. S. mining and beneficiating of
ores containing zirconium minerals is zircon concentrate, a by-
product from titanium mineral production.
A-30
-------
APPENDIX B
Raw Materials, Minerals, and Products Utilized
in Metal-Mining and Milling Industry
-------
TABLE 1. UNITED STATES METAL-MINING INDUSTRY: METALS, RAW MATERIALS, MINERALS, AND PRODUCTS
(MAJOR GROUP 10, SIC)
Sg-T '-'.•?-- ... ."7==
:;etai
Alu.-ni.num
Antir.ony
Beryllium
Colimblum"""
(N'icbiun)
Copper
Chcn-
ical
Sym-
bol
Al
Sb
Be
- Cb
(Nb)
Cu
SIC
No.
1051
1099
1099
Mining and
R.iw Materials
Ore Deposit Name
HifJi-Crndc Bauxite 'Deposit
Lov-Grac!c Bauxite Deposit
Stibnite Content Deposit
P*cbnatitic Ore Body
Bertrandite Ore Body
1061 — rrirar-Tarth 'Complex Deposit
1021
High-Grade Ore Deposit
Bcnof iciatint;
Principal
Mineral (s)
Bauxite
S tibnite
Beryl
Bcrtrandite
Colurr.bi te
Chalcocite
Materials
Bcncficiatcd Product (s), Nair.es
Metallurgical Grade Bauxite
Nonmc t.i Llurgical Grade Bauxite
Higli-Grndo Ore Concentrate
Medium-Grade Ore Concentrate
Beryl Concentrate
BoSO^ Filtrate
Columbite Concentrate
Hiph-Cradc Ore Concentrate
Produced an
a. Principal
b. Coproduct
c. By-Product
a
a, b, c
a
c
a, b, c
CO
I
Gold
Iron
Au
Fe
Lead Pb
Manganese Kn
Lov-to-High Grade Ore Deposit
Very low Grade Ore Deposit
1041 Placer Gold Deposit
Lcde Gold Deposit
1011 Magnetite Ore Body
Magnetite-Hematite Ore Body
Hematite Ore Body
Hematitc-Limonite Ore Body
Iron Pyrites Ore Body
M-iM-anifcrous Iron Ore Body
Linonitc-Sidcritc Ore Body
Jas'pilito Ore Body
T.iconite Ore Body
1031 Lead Ore Deposit
Lead-Zinc Ore Deposit .
1061 Iron-Manganese Deposit
Zinc Ore Deposit
Chalcopyrite
Cuprite
Malacliite
Native Copper
Azurite
Native Gold
Magnetite
Hematite
Pyrite
Sidcrite
Llmonttc
Galena
Cerrusite
Manganite
Pyrolueite
Filter Cake
Native Copper Concentrate
Ccnent Copper
Cement Copper Concentrate
Concentrated Copper Solution
Hich Gold Ore Concentrate a, b, c
Gold Amalgam
Crude Gold Bullion
.Concentrated Gold Solution
"Black" Powder, Gold Precipitate
Run of Mine Ore a, b, c
Direct Shipping Ore
Iron Ore Concentrate
Man^ainferous Iron Ore Concentrate
Iron Ore Sinter
Iron Ore Briquettes
Iron Ore Pellets
Iron Ore Nodules
Lead Concentrate a, b, c
High Manganese Content Iron Ore c
Manganese in Residue
-------
TABLE 1: (Continued)
ro
Chem-
ical
Sym-
Mctal hoi
Mercury
Molybdenum
Nickel
(a)*
Platinum v '
Radius
Rare (b)*
Earths w
Silver
Tantalum
Thorium
Titanium
Tin -,'
Tungsten
Uranium
Vanadium
Kg
Mo
Ni
Pt
Ra
RE
Ag
Ta
Th
Ti
Sn
W
U
V
SIC
No.
1092
1061
1061
1099
1094
1099
1044
1061
1099
1099
1099
1061
1094
1094
Mining and
Raw Materials
Ore Deposit Name
Cinnabar Content Deposit
Molybdenum Content Deposit
Nickel Content
Garnicritc Deposit
Bcncflciatinn Materials Produced as
Pr inc ipal
Mineral (s)
Cinnabar
Molybdenite
Carnierite
Platinum Content Placer Deposit Native Pt-Group
Uranium Content Deposit
Bar, tnitsite Deposit
Rare-Earth Complex Deposit
Silver Complex Deposit
Silver-Gold Deposit
Rare-Earth Complex Deposit
Titania Placer Deposit
Molybdenum Content Deposit
Titnnia Placer Deposit
Titania-Nonmc tal Lode Deposit
Titania-Magnctite Deposit
Molybdenum Content Deposit
Schcelite Content Deposit
Uranium Content Deposit
Complex Vanadium Minerals Deposit
>
Metals
Uranlnite
Bastnasite
Tetrahcdrite
Elcc tra
Tan ta lite
Monazite
Iltncni te
Rutilc
Lcucoxcne
Cassitcrite
Schcolite
Uranini te
Thucholite
Carnotite
Montroseite
Fervanite
a. Principal
b. Coproduct
Bcncficiatcd Product (s), Names c. Ey- Product
Cinnabar Ore Concentrate a, c
Mercury (Metal)
Molybdenite Concentrate a, b, c
Fcrronickel Alloy (Metal) a
Platinum Content Concentrate a, b, c
Not recovered as a product
Rare-Earth Concentrate a, c
Silver-Rase-Mctal Concentrate a, b, c
Silver-Gold Solution
Tan ta lite Concentrate * c
Monazite Concentrate' ' c
Rutilc Concentrate a, b
Ilmcnite Concentrate
Rich Titania Content Concentrate.
Lean Titania Concentrate
Nonmagnetic Tin Concentrate c
Schcelite Concentrate ,
a . b t c
Ammonium Paratungs tate
Yellow Cake a, b
Technical Grade V205 a» b, c
Ammonium Mctavanadate
Pure Vanadium Pcntoxide
* Footnotes on next page.
-------
TABLE 1: (Continued)
DO
I
CO
Ketal
Zinc
Zirconium
Chcn-
ical
Syr.i-
bol
Zn
Zr
SIC
No.
1031
1099
Mininr, and
Rnw Materials
-Ore Deposit Name
Zinc Ore Deposit
Zinc-Lead Ore Deposit
Titania Placer Deposit
Bcncf iciating
Principal
Mineral (s)
Sphalerite
Cal ami no
Zircon
Materials
Eencficiatcd Product(s), Names
Zinc Concentrate
Zircon Concentrate
Produced as
a. Principal
b. Coprociuct
c. Ey-Product
a, b, c
c
(a) Category includes all of the Platinum-Group Metals: platinum (Pt) palladium (Pd) iridium (Ir) osmium (Os) rhodium (Rh)
and ruthenium, Ru.
(b) Category includes all of the Rare-Earth Metals: cerium (Ce) dysprosium (Dy) erbium (Er) europium. ( Eu) gadolinium (Gd)
holmium (ilo) lanthanum (La) lutctium (Lu) ncodynium (Nd) prascodynium (Pr) promcthium. (Pm) samarium (Sci) terbium (Tb)
thulium (Tn) and ytterbium (Yb). In addition, some commercial groups choose to include yttrium (Y) and scandium .(SC) in
die rare-earths group.
(c) Thorium is recovered as a by-product during the recovery of rare-earth oxides and metals from cionazite. Monazite is
itself a by-product from titanium and molybdenum mineral recovery operations.
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TABLE 2. RAW MATERIALS UTILIZED IN THE MINING AND BENEFICIATING OF METALLIC ORES
(Examolps)
Process
Process Step
Materials and Remarks
Mining
Ore Body
Conditioning
Ore digging & loading
Transportation
Beneficiation Crushing & Grinding
Classifying,Washing
Flotation (e.g.MoS,)
Leaching
Explosives (fuel oil as explosives
extender)
Fuels and lubricants (e.g., for drilling
equipment)
Fuels and lubricants (for equipment
operation)
Wooden timbers (for nine support or ore-
gangue separation)
Steel (chain link fence and rods for nine
support. Elevator and building construc-
tion)
Fuels and lubricants (tire rubber is-
significant)
Fuels and lubricants (for operating equip-
ment) '
Steel [balls & liners] (1.5 pounds per ton
of ore)
Water (4 tons per ton of ore--added in
grinding, carried through to pulp dewater-
ing, mostly recycled)
Fuels & lubricants (for operating equipment)
Lime (conditioner,e.g.,pH modifier)
Zinc sulfate (conditioner 0.1 pounds per
ton of ore)
Sodium sulfide (depressent 0.08 pounds per
ton of ore)
Sodium cyanide (depressent 0.005 pounds
per ton of ore)
1,1,3 Triethoxy butane (0.05 pounds per
ton of ore)
Zanthate ester (0.007 pounds per ton of
ore)
"N" Silicate (0.20 pounds per ton of ore)
Phosphorus pentasulfide (0.06 pounds per
ton of ore)
Potassium permanganete (0.003 pounds per
ton of ore)
Polyacrylanid [water soluble] (0.008
pounds per ton of ore)
Sulfuric acid (e.g. copper leaching)
Sodiun cyanide (e.g. gold leaching)
B-4
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TECHNICAL REPORT DAT A
(Please read lititnictions at!. 'J.tc waiw fa fore c
1. REPORT NO.
EPA-600/2-76-167
2.
3. RECFHIENT'S ACCESSION NO.
4. TITLE AND SUBTITLE
Metals Mining and Milling Process Profiles with
Environmental Aspects
5. REPORT DATE
June 1976
S. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
R.J. Nerkervis and J.B. Hallowell
3. PERFORMING ORGANIZATION REPORT NO,
9. PERFORMING ORGANIZATION NAME AND ADDRESS
Battelle Columbus Laboratories
505 King Avenue
Columbus, Ohio 43201
10. PROGBAM ELEMENT NO,
1AB015; ROAP 21AFH-025
J1. CONTRACT/GRANT NO.
68-02-1323, Task 35
12. SPONSORING AGENCY NAME AND ADDRESS
EPA, Office of Research and Development
Industrial Environmental Research Laboratory
Research Triangle Park. NC 27711
33. TYPE OF REPORT AND PERIOD COVERED
Task Final; 8/75-5/76
34. SPONSORING AGENCY CODE
EPA-ORD
15. SUPPLEMENTARY NOTES jERL-RTP task officer for this report is W.G. Tucker, Mail Drop
63, 919/549-8411, Ext 2745.
is. ABSTRACT
repOrt describes the environmental aspects of metals mining and
milling (concentration) operations in the U.S. The metals include Al, Sb, Be, Cu,
Au, Fe, Pb, Zn, Hg, Mo, Ni, Pt, the rare earth metals, Ag, Ti, W, U, and V.
The types of environmental impacts associated with operations from mining through
production of concentrate are described in general terms; the nature of each metal
category of the industry is described in terms of number and locations of plants,
names of producing companies, production levels, and other characteristics of the
industry. Flowsheets are presented which indicate raw materials inputs, unit oper-
ations , and intermediate and final products. Each unit process is described in terms
of function, input materials, operating conditions, utilities and energy use, and waste
streams. The descriptions of unit processes identify waste streams in terms of
emissions to the air, water effluents, and solid wastes disposed to the land. The
approximately 185 unit operations described include mining, dredging, crushing,
flotation, leaching, sintering, and nodulizing. The most common waste streams are
dusts from mining and crushing operations, liquid streams from mine drainage,
flotation operations, tailings ponds, and leaching operations.
17.
KEY WORDS AMD
BWr ANAL YS1W
DESCRIPTORS
Pollution
Metals
Metal Industry
Mining
Comminution
Industrial Processes
ENDED TERMS
Pollution Control
Stationary Sources
Production Levels
13. DISTRIBUTION STATEMENT
Unlimited
CL.VKKS (This Report)
ij20. SECaafllTY CLASS (This page)
Unclassified
c. COSATI Field/Group
13B
11F,07B
05C
081
13H,07A
21. NO. OF PAGES
313
22. PRICE
EPA Form 2220-1 (9-73)
B-5
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