WATER POLLUTION CONTROL RESEARCH SERIES
1401ODZM 08/70
Feasibility Study of Mining Coal
in an
Oxygen Free Atmosphere
U.S. DEPARTMENT OF THE INTERIOR • FEDERAL WATER QUALITY ADMINISTRATION
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Feasibility Study of Mining Coal
in an
Oxygen Free Atmosphere
A DEMONSTRATION OF A NEW MINING TECHNIQUE TO
PREVENT THE FORMATION OF MINE ACID
IN AN ACTIVE DEEP MINE
PHASE I
BY
ISLAND CREEK COAL COMPANY
ISLAND CREEK DIVISION
HOLDEN, WEST VIRGINIA 25625
AND
CYRUS WM. RICE DIVISION
NUS CORPORATION
PITTSBURGH, PENNSYLVANIA 15220
FOR THE
FEDERAL WATER QUALITY ADMINISTRATION
DEPARTMENT OF THE INTERIOR
PROGRAM NO. 14010 DZM
AUGUST, 1970
For sale by the Superintendent of Documents, U.S. Government Printing Office
Washington, D.C. 20402 - Price $1.50
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FWQA REVIEW NOTICE
This report has been reviewed by the Federal Water
Quality Administration and approved for publica-
tion. Approval does not signify that the contents
necessarily reflect the view and policies of the
Federal Water Quality Administration, nor does
mention of trade names or commercial products con-
stitute endorsement or recommendation for use.
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ABSTRACT
A systems evaluation was made to determine the engineering
feasibility and probable economics of mining coal in an
active deep mine in an oxygen free atmosphere using current
technology in the application of life support systems to
conventional coal mining techniques. The project was Phase
I of a four phase program to demonstrate that mining coal
in an oxygen free atmosphere will prevent the formation of
acid mine water. Other major benefits include improved
working conditions from a health and safety standpoint.
A detailed investigation was conducted into the application
and suitability of commercially available inert gas
generators, life support clothing and equipment, and
personnel communications systems. Three sites were
investigated for a demonstration mine.
The investigation revealed it is feasible from an engineer-
ing standpoint to mine coal in an oxygen free atmosphere.
Life support and associated equipment are available
essentially off-the-shelf. A deep- mine using conventional
mining equipment can be designed to operate in an oxygen
free atmosphere. The comparative economics are extremely
favorable when methane gas is recovered and sold.
This report was submitted in fulfillment of Program Grant
No. 14010 DZM between the Federal Water Quality Adminis-
tration and Island Creek Coal Company.
Key Words: Acid Mine Water, Inert Gas Blanketing, Mining,
Life Support Systems, Mining Engineering,
Health, Safety, Communication Systems, Data
Acquisition.
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CONTENTS
Section Page
I. Conclusions 1
II. Recommendations 3
III. Summary 5
IV. Introduction 19
V. Miners' Life Support System (MLSS) 21
VI. Communications 47
VII. Gas Blanketing System 57
VIII. Dust and Heat Control 69
IX. In Mine Systems 75
X. Personnel Program 81
XI. Instrumentation 97
XII. Data Collection 109
XIII. Safety 119
XIV. Projected Mining Costs 127
XV. Mine Site Evaluation 131
XVI. External Systems and Facilities 155
XVII. Acknowledgments 159
XVIII. References 161
XIX. Publications 163
IV
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FIGURES
Page
1 Gas Tight Middle Garment 33
2 Miner in Life Support Suit 34
3 Mine Personnel Rebreather System 37
4 Proposed Communications Antenna System 55
5 Preliminary Refuge Station Gas Lock Design 59
6 Equipment and Personnel Lock 60
7 Coal Handling Concept 61
8 Inert Gas System-Demonstration Mine 67
9 Blanketing Gas Distribution System-Demonstration
Mine 68
10 Section of Mine and Cover 76
11 Plan of Development and Atmosphere Control
System 77
12 Sampling Points 99
13 Sampling Scheme 100
14 Gas Sample Lines 101
15 Watersheds-Kan awha and Big Sandy Rivers 132
16 Test Column Arrangement 145
17 Pond Fork Column Effluent 146
18 Rock House Column Effluent 147
19 Red Jacket Column Effluent 148
20 Mine Location Map 156
21 External Systems and Facilities 157
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TABLES
Page
1 Operational Heat Load 70
2 Projected Capital Costs 129
3 Projected Operating Costs 130
4 Kanawha River Basin 134
5 Big Sandy River Basin 135
6 Field Sample-Pond Fork Mine Discharge 141
7 Field Sample-Rock House Mine Discharge 142
8 Field Sample-Red Jacket Mine Discharge 143
9 Column Test Conditions-Three Sites 149
10 Coal Refuse Analyses 150
11 Pond Fork Refuse-Column Effluent 151
12 Rock House Fork Refuse-Column Effluent 152
13 Red Jacket Refuse-Column Effluent 153
VI
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SECTION I
CONCLUSIONS
The feasibility study conducted on the application of an
oxygen free atmosphere to the mining of coal has developed
the following conclusions:
1. It will be possible with today's technology to mine
coal in a deep mine in an oxygen free atmosphere and that
at least in the instance of gassy mines, the economics of
such operation will be highly favorable.
2. Modification of existing conventional mining equipment
will be minimal for such operation.
3. Present day miners skilled in operating conventional
as well as continuous and long wall mining equipment have
the necessary skills to operate in an oxygen free atmos-
phere.
4. The outside air ventilated refuge station located near
the working section will allow the'miners to take regular
breaks from operation of equipment in addition to providing
a safe haven in the event of an accident or emergency.
5. The miner's life support suits and helmets (under-
garment, gas tight suit and helmet, coverall) are available
essentially off-the-shelf. j
6. The two-piece miner's life support rebreather unit
(portable 02 module, fixed chiller module) must be con-
structed for the particular application but employs
standard off-the-shelf components and makes use of a large
reservoir of existing technology in design and fabrication.
7. Miner's emergency rebreathing and rescue equipment is
available off-the-shelf.
8. Communications employ standard FM transceivers and
systems demonstrated workable in subway stations. Such
units are completely off-the-shelf and are widely used in
industrial applications.
9. Natural gas burning inert gas generators are off-the-
shelf items in the desired sizes, reliable and economic to
operate.
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10. Removal of heat generated by the mining equipment can
be handled in a straightforward fashion by recycling the
oxygen free mine atmosphere using the external ventilation
fan provided for emergency air ventilation along with
requisite duct work.
11. The amount of heat to be removed from recycle gas
requires only modestly sized mechanical refrigeration
equipment (50 tons per day per active section) and no new
technology.
12. Dust control at 12,000 CFM circulation rate at the
face in each section should not present either greater nor
less a problem from a visibility viewpoint than is
currently encountered with conventional equipment opera-
tion. The recycling of the mine atmosphere offers the
possibility of complete dust control through the installa-
tion of external dust removal equipment.
13. The gas lock design is straightforward and employs
established principles of gas curtain designs for such
purposes and requires no new developments.
14. Preliminary estimates of the costs of equipping a
5,000 ton per day deep coal mine show that the added cost
for inert gas blanketing would probably not exceed 12% of
the installed cost of the mine. In a non-gassy mine, the
operating costs of inert gas operation may increase the
operating costs of the mine by a few percent. In the case
of a gassy deep coal mine, operation in an inert gas
atmosphere may actually decrease the cost of the mine
operation by as much as 20% when credit is applied for the
methane gas that is trapped and sold.
15. Sufficient data could be gathered in a single section
demonstration mine operated in an oxygen free atmosphere
that sound projections to full scale deep mining operation
with either nitrogen or methane blanketing could be made.
Such a demonstration would be necessary before any full
scale application could occur.
16. If a demonstration mine were to be constructed, the
Pond Fork site of" Island Creek Coal Company in Boone
County, West Virginia would allow the use of the adjacent
active mine's external coal preparation facilities and
utilities and would be suitable from geologic considera-
tions for a demonstration project. There is a good
chance that the site would produce mildly acid mine
drainage in the absence of blanketing.
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SECTION II
RECOMMENDATIONS
The feasibility study on the application of an oxygen free
atmosphere to deep coal mining has developed a series of
conclusions regarding the key factors involved. Based upon
those conclusions, the following recommendations are
extended:
1. The important life support components of the proposed
mining system should be tested in a Phase II program in
an active air ventilated deep coal mine using conventional
mining equipment. Specifically, the miner's life support
suit, the miner's life support rebreather unit with tether
hoses, the miner's emergency rebreather unit and the
miner's communication system should be purchased from
available suppliers, tested, modified as required, and
retested. The purpose of the testing is to develop a
final design and specifications as well as operations
and maintenance manuals for these systems suitable for the
miner's use in an oxygen free atmosphere when operating
standard mining equipment. The initial specifications for
the components to be tested should be those developed in
the Phase I feasibility study.
2. At least one of each piece of conventional rubber
tired coal mining equipment required for operation of a
single section should be obtained for a Phase II test
program. The required modifications to the life support
systems should be developed based on operation of this
equipment as well as any modifications of the mining
equipment itself required to accommodate the life support
systems. Sufficient life support and communication
components should be obtained to equip two miners for the
test program.
3. Detailed plans, specifications and estimated costs
should be prepared in the Phase II program for construction
and operation of a demonstration mine to be constructed if
the results of the Phase II program warrant a Phase III pro-
gram. The mine consisting of a single active section should
be operated in an oxygen free, nitrogen-carbon dioxide
atmosphere by a mining crew of approximately ten men. The
plans should be based upon the use of the coal preparation
and support facilities of an active mine adjacent but
unconnected with the demonstration mine. Such plans should
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include those for the mine proper and for external support
buildings special to the project as well as those for the
gas locks, inert gas system, heat and dust control, gas and
water quality instruments, communications, refuge station,
and coal handling. The bases for the designs should be
those developed by the feasibility study.
4. Provision should be made in the foregoing design of the
demonstration mine to accommodate installation of a room to
contain a supply of a known acid producing pyritic material
through which a portion of the mine drainage may be
diverted so as to augment the data obtained on the normal
drainage characteristics of the selected mine. The
demonstration mine should contain only one air ventilated
refuge station. The extent of mining anticipated for a
demonstration program would be sufficiently limited that
one refuge station will be within easy walking distance of
the working faces. The oxygen free atmosphere to be
employed in the demonstration mine should be achieved by
use of exhaust gas from combustion of natural gas in
standard industrial inert gas generators of this type.
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SECTION III
SUMMARY
Miner's Life Support System
The miner in the proposed process must work in an atmosphere
that will have less than 0.1% oxygen and will be at 100%
relative humidity. The life support system thus must not
only supply breathing oxygen but must remove carbon dioxide
all without contributing significantly to the oxygen content
in the mine. The life support system must be comfortable
for eight hours per day, five days per week. It cannot
unduly hinder the miner in his operation of conventional
mining equipment.
Face masks, helmets with neck seals, helmets with torso
seals, liquid cooled undergarments, full suits with cuff
seals and suits with pressure tight gloves and boots were
considered.
It is concluded that each miner should wear a full suit and
helmet. The helmet can be equipped with a fitting to attach
a standard miner's lamp. A voicemitter diaphragm can be
located over one ear enabling the miner to hear directly
sounds outside the suit and surrounding him. The other ear-
piece in the helmet should be equipped with a communications
earphone. A mouthpiece connected to an emergency breathing
apparatus should be installed in the helmet in a position
easily accessible to the miner. The helmet can be attached
to the suit with a sealed clamping ring, and should be
readily removable and replaceable by the miner.
A gas impervious middle garment should be used/ constructed
of lightweight rubberized cloth. The garment can be fitted
with gloves and boots detachable via ring seals at the
ankles and wrists. The suit can be designed to operate at
one-half inch water pressure relative to the outside
atmosphere. A maximum leakage rate of 1 cubic foot per
hour at 7" H2O pressure should be specified. An outer wear
resistant garment should be worn over the gas impervious
middle garment.
The 100% relative humidity in the mine atmosphere plus the
heat generated by the mining equipment requires that the
metabolic heat and perspiration in the suit of the miner be
removed by external means. The oxygen requirements of the
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miner must be supplied both during operation and during
movement to and from the equipment. The components of the
life support system must be reliable and off-the-shelf.
The weight of the oxygen supply and carbon dioxide absorber
must be low enough to permit twelve hours supply in a
portable unit of modest weight able to be carried by the
miner to and from his work.
In approaching the life support problem, consideration was
given to cryogenic oxygen, pressure cylinder oxygen,
potassium superoxide, chlorate candles, and Baralyme
absorbers for breathing requirements. Cryogenic gas and
mechanical refrigeration were considered for removing heat.
Single units as well as dual units were examined. Multiple,
crew type systems were also considered. The relative
merits of replacing oxygen and CO2 units inside the mine
versus outside the mine were studied.
It is concluded that one complete rebreather system should
be used for each miner. Such a rebreather system can
consist of three components: (1) An umbilical hose for
conveying breathing and ventilating air to and from the
miner; (2) A portable oxygen module; and (3) A fixed chiller
module. The umbilical hose should be flexible with quick,
self-closing disconnects on each end. Hose lengths can be
variable up to 20 feet depending upon the anticipated
activity of the miner.
The portable oxygen module can contain the oxygen supply,
the C02 absorber, the circulating blower, and the battery
for blower operation during such times that the module is
disconnected from an outside power supply. The module can
be compact in size, weighing approximately 30 pounds. The
oxygen supply can be via a demand regulator from a 2,200
psi cylinder of pressurized gaseous oxygen sufficient to
supply 12 hour requirement based upon a 0.2 pounds of oxygen
per hour consumption. The C02 absorber can be a Baralyme
unit of sufficient capacity for 12 hours operation.
The miner should carry the portable oxygen module with him
whenever he leaves his piece of operating equipment to go
to the refuge station or to exit the mine. During such
tiroes, the portable oxygen module can supply the necessary
oxygen requirements and CO2 removal, but cannot remove any
heat or perspiration. The battery should have sufficient
capacity for two hours of blower, operation and can be re-
charged each time the portable oxygen module is reconnected
to the power supply associated with a fixed chiller module.
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The fixed chiller module can contain the mechanical refrig-
eration unit capable of removing 2,000 BTU's per hour from
the recirculating air to the miner. The recycled air should
be controlled at 72°F and 40% relative humidity as it is
supplied to the suit. The fixed chiller module estimated
to weigh approximately 100 pounds should be mounted on the
mining equipment or transport equipment and should be
powered from it.
Failure of the rebreather system for any reason, or failure
of the miner's suit by tearing or by fracturing the face
plate requires that an emergency back up system be provided
that will operate independently of either the normal re-
breather system or the suit. Sufficient capacity must exist
in the emergency unit that it will allow the miner safe
passage to a refuge station or out of the mine. The unit
must be small enough and light enough to allow the miner to
carry it with him at all times without-"unduly hindering his
activity. The unit must also have a long shelf life or have
a ready means of assuring its serviceability. No provision
for body heat removal need be made.
Chemical oxygen rebreathers as well as pressure cylinder
oxygen rebreathers were considered with capacity up to one
hour. It is concluded that a satisfactory system can con-
sist of a potassium superoxide canister that is the source
of oxygen as well as being the CO2 and moisture absorber.
The canister can contain a chlorate candle for rapid
ignition and quick supply of oxygen for one hour. A re-
breather bag should be used and the assembly connected to
the helmet with quick disconnect hoses which, in turn, lead
to the mouthpiece previously described. The miner, by
breathing in and out through his mouthpiece, will be able
to sustain himself.
Communications
With the miner completely enclosed in a life support suit,
communication between miners as well as communication to a
refuge station and to a control point outside the mine must
be provided. The system employed should be rugged, highly
reliable, lightweight and not hinder the activity of the
miner. It should not require that he manipulate the device
whenever he wishes to talk. Communication between miners
must include those riding on shuttle cars as well as working
out of sight in separate rooms or passageways.
Hard wire connection through cables on equipment and junc-
tion boxes, passageways, inductive wireless transmission,
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low and high frequency radio communication were considered.
Availability and reliability of equipment or system to
operations underground was a requisite. Direct communica-
tion by loudspeakers and microphones was also studied.
It is concluded that individual high frequency FM trans-
mitter receivers should be used. The units can be carried
by the miner and connected to the headset within the
helmet. A voice operated microphone can be used which will
enable the miner to communicate without having to activate
any switches. Communication should be by transmission line
of sight to an antenna cable which will pick up the signal
and carry it to an external remote base station. The base
station receives the individual signals and rebroadcasts
same at much higher power back on to the antenna cable.
The antenna cable, which can be strung along the ceiling in
active crosscuts and down one entry, can rebroadcast the
signal from the base station to be picked up by the
individual miner receivers. The previously described
voicemitters on each helmet should enable the miner to hear
sounds made by his equipment in operation as well as to
listen to sounds made by the roof so as to detect unsafe
conditions.
Gas Blanketing System
A non-combustible oxygen free inert gas must be provided to
interface between the outside air atmosphere and the pres-
surized oxygen free atmosphere in a sealed mine. In the
instance of a non-gassy mine, the inert gas used for the
interface would also be used as the gas within the mine
proper. The interface occurs in the gas locks for person-
nel, for equipment, and for the coal removed. The inert
gas employed for purging the gas locks must be inexpensive
and readily available at the mine site. The source must
provide for short duration high demand flow rates.
Consideration was given to carbon dioxide, liquid nitrogen,
locally cryogenically produced nitrogen, and to combustion
exhaust gas, a mixture of nitrogen, carbon dioxide, and
water vapor.
It is concluded that the inert gas for purging the gas locks
and for blanketing and sealing a non-gassy mine should be
obtained as the product combustion gas from natural gas and
air burned in a standard industrial inert gas generator.
The effluent from the generators should go to a gas holder
tank (100,000 cubic foot capacity in the case of the
demonstration example).
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The gas holder can smooth out the demand which reaches peaks
during periods of maximum personnel and equipment locking.
Inert gas can be maintained in the holder at one to two
inches of water pressure, the same pressure as the mine
proper.
The inert gas within the mine should be recycled continuously
at 12,000 CFM per section using the ventilation fan provided
for initial air development. This same fan can serve for
emergency purposes when it might become necessary to abort
the gas blanket in the mine and to ventilate the mine with
air. In gassy mine operations, the circulating inert gas
can be natural gas from the coal formation. Pressurization
of the mine would thus come from the natural gas generated
within and be maintained by proper pressure control devices.
Natural gas released from the mine can be recovered and
pressurized for discharge into a natural gas pipeline system.
It is necessary that personnel and equipment be able to
routinely enter and leave the oxygen free atmosphere in a
sealed mine. During such transit, air cannot be allowed to
enter the mine, nor can the mine atmosphere, particularly a
methane atmosphere, be allowed to enter the outside air
indiscriminately. The amount of inert nitrogen gas used for
the interface between inside and outside the mine must be
minimized.
Completely purged gas locks were studied as well as gas
curtain designs where the primary effect is to prevent mix-
tures of air or mine atmosphere in the lock. A double bin
design and a water seal design were investigated for convey-
ing the coal from a mine while maintaining the mine in a
sealed condition.
It is concluded that the gas locks provided for personnel
entry into the refuge stations and for personnel and equip-
ment entry and egress from the mine proper should be
designed with two doors interlocked so that only one door
will open at a time, and that exhaust from the gas locks
should be from plenums surrounding each door on the inside
of the gas lock producing a gas curtain which will prevent
the atmosphere within the gas lock and that within the mine
or outside the mine from mixing.
The conveyor belt emerging from the mine should be contained
in a duct which can extend from the entry to the top of the
coal bin. The coal bin should be a two section bin with a
gate valve between each and at the exit from the lower bin.
Coal can discharge into the upper bin under the atmosphere
of the mine, which atmosphere would be maintained within the
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duct and in the top of the bin. Inert gas can be supplied
to the lower bin to purge it during such time as coal is
transferred from the upper bin to the lower bin. Inert gas
can also be supplied to the lower bin when coal is being
discharged from it into the truck for transport to the
preparation plant. Gas curtains exhausting to fans can be
used around the exit of each of the gates in the coal bin
to minimize mixture of the outside atmosphere or mine
atmosphere with the lower bin. It is estimated, for
example, that the total inert gas demands for the proposed
single section demonstration mine could be as much as
600,000 cubic feet per day for a one shift per day opera-
tion.
Dust and Heat Control
The electrical power required to operate the pieces of
equipment used in mining coal results in the generation of
heat in the working face area. Normal air ventilation used
for control of methane or dust removes this heat conveying
part to walls of the mine and rejecting the remainder in the
exhaust to the outside atmosphere. Dust generated by the
mining equipment is controlled to a large degree by water
sprays but remaining dust is conveyed from the working area
by air ventilation. This residual dust is deposited in
passage through the mine with some small unknown fraction
finally rejected to the outside in the exhaust. In a
sealed mine, the moisture in the ground produces a 100%
relative humidity in the mine atmosphere at whatever the
temperature of the mine finally results.
The steady state rejection of heat to mine walls was con-
sidered. Liquid cooling of equipment, local recirculation
through chiller coils, as well as general recirculation
were studied. Local dust filters were also considered. The
effect of miner suit temperature was taken into account.
The use of external dust removal processes was investigated.
It is concluded that the heat generated by the mining
equipment, estimated at 600,000 BTU's per hour per operating
section, can be removed from the working face by recircula-
tion of the mine atmosphere at 12,000 CFM per section using
the external mine fan properly ducted. Some heat will be
removed by conduction to the walls of the mine and some by
the coal removed. Most of the heat must be removed however
by mechanical refrigeration provided outside the mine.
Chiller coils can be located in the duct work at the inlet
to the circulating fan. Water sprays can be provided to
wash off any dust depositing on the chiller coils. Fifty
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tons of mechanical refrigeration capacity are estimated as
sufficient to provide the required cooling for a single
section. Stoppings can be used to convey the cooled dis-
charge from the ventilating fan to the working crosscut.
With 12,000 CFM gas flow rates supplied at the working
face per section, it is anticipated that the dust problems
will be no more nor no less than those encountered in
equivalent standard open air ventilated operation. The
recycling gas temperature should be controlled between 55
and 74°F at 100% relative humidity in order to avoid con-
densation of the mine atmosphere on the suit.
In-Mine Systems
A mine using the oxygen free blanketing process should be
constructed in a fashion normal for the conventional
mining equipment procedures chosen. The development of the
desired single section in the case of the proposed demon-
stration mine should be away from an adjacent active mine
but constructed in a way not to preclude eventual operation
in an air ventilated status to recover the remaining coal
if the inert process is abandoned.
In opening a new mine to use the inert process only, three
entries need be driven. Once inside, development of the
five headings for the first section can be on 60 foot
centers, for example in the case of the demonstration mine.
Later, after initial development, the breakthroughs can be
driven on 80 foot centers. The width of the mine entries
and headings can be 20 feet. During initial development, a
ventilation fan can be used to drive in several hundred
feet under conventional ventilation to construct the first
three breakthroughs before placing the mine in an oxygen
free status. Five parallel headings can be used to form
the single section desired.
It is necessary that a place be provided in a sealed mine
that will be air ventilated at all times and uncontaminated
by the oxygen free mine atmosphere. Such a refuge station
must serve to house safely an entire section crew and pro-
vide them with sanitary facilities as well as emergency
supplies. The refuge should be within several minutes walk-
ing distance of the working face so that any required breaks
in work activity may be taken conveniently. Since the
30-60" height of seams of general interest does not allow
the stand-up required for suit servicing, opening up to 84"
is required for the refuges and thus portable shelters with
self-contained air were only briefly considered.
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A refuge station of desired design should be located in the
proposed demonstration mine, for example, just beyond the
entries after the start of the breakthroughs. A convenient
size is approximately 20 feet wide, 40 feet deep, with the
roof opened to a 7 foot height. It is practical to seal
with concrete block and to plaster the block with cement and
bituminous-based material to insure its being gas tight.
A single gas lock will provide sufficient access and it can
be sized to accommodate a man on a stretcher. The gas lock
will serve as the entry from the mine into the refuge
station. Two 10 inch diameter boreholes should be drilled
from the surface into the refuge for ventilation. These
boreholes can also be used to supply power and communica-
tions separate from the mine proper. One of the boreholes
can also serve to exhaust the atmosphere in the gas lock
during passage of personnel to and from the refuge. The
refuge should be supplied with sanitary facilities,
emergency maintenance facilities for the life support suits,
spare life support system units, emergency rescue units, as
well as first aid equipment.
The necessity of maintaining the mine in a tightly sealed
condition dictates the use of conveyor belts rather than
tracks for coal movement out of the mine. The gas locking
of individual coal cars would be time consuming and require
very large quantities of inert gas. Coal movement within
a large mine could be either by tracked equipment or by belt
with discharge from the mine to the outside atmosphere
always by belt.
The proposed demonstration mine being only a single section
should thus be all rubber-tired without tracks or tracked
equipment. In this case, the coal removal would be by a
single conveyor to a bin outside the mine from which the
coal would be hauled by truck to the coal preparation plant.
Modifications will have to be made to the standard mining
equipment for the installation of power converters and racks
to support the individual life support systems required for
the equipment operators.
Routine maintenance of mining equipment can be conducted
within the oxygen free atmosphere in the mine. Major
maintenance on equipment can be performed outside the mine
in the shop. Passage of the equipment in and out of the
mine for maintenance can be through a gas lock in one of
the entries; this gas lock must be constructed of
sufficient size to take the largest piece of equipment
involved.
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Miner Training Program
Miners by their own selection and pursuit of a mining
career demonstrate that they do not experience claustropho-
bia; they have not however had experience in the special
problems associated with a life support suit. Discussion
with NASA was held on their experience with skilled labor
at Cape Kennedy operating in such suits. Island Creek's
experience with miner training was considered also. It is
concluded that present job specifications can be employed
for each of the men involved, supplemented with thorough
physical exams and only sufficient psychological testing to
determine that the individual will be able to operate in a
life support suit.
Training of experienced miners in the functioning of their
suit, their life support and emergency breathing apparatus
will be necessary for their safety. While each miner will
be familiar with normal operation of mining equipment,
further familiarization with such operation while wearing
a suit is advisable before going under an oxygen free
atmosphere.
A training facility should be located outside the sealed
mine. This facility should contain a classroom, a small
gas lock chamber in which men can be accustomed to the
safety of their suits and apparatus, and a garage in which
individual pieces of mining equipment can be operated by
the men while wearing the life support suits so that they
can become accustomed to such operation before having to
perform it within the confines of the mine proper.
Approximately one month is anticipated for training a ten
man section crew before they would begin operation in an
oxygen free atmosphere.
Data Collection
One of the primary purposes of the inert gas program is to
effectively prevent the formation of acid mine drainage.
How drainage quality will vary with time from transition
from air to inert gas status is thus of great interest.
Comparison with a reference condition is desirable.
Manual as well as automatic recording analysis of drainage
quality was studied for a sealed mine.
It is concluded that continuous instrumental monitors
should be provided to measure the quantity and quality of
the effluent from the sealed mine. In addition, in the
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proposed demonstration mine, the flow and quality should be
measured in the stream above and below the mine site. The
continuous monitoring program should be supplemented with
automatic sampling and laboratory analyses for the remaining
components of interest. In the case of the proposed demon-
stration program, provision can be made for the insertion
of heavily pyritic material within the demonstration mine
and for measurement of the drainage that would ensue from it
as an additional control.
Monitoring of the mine atmosphere as well as the atmosphere
in the gas locks and refuges should be continuous for each
of the gases of interest. Such instrumentation is available
and reliable. It can be located either in refuge stations
or external to the mine, whichever is most convenient. All
results can be displayed in a central control room.
Safety
A_personnel accident in an oxygen free mine requires that
first consideration be given to rescue apparatus that will
provide breathing atmosphere for an unconscious and possibly
stunned individual completely separate from any of the
breathing apparatus carried by the individual. The appa-
ratus must be portable, reliable and have a high shelf life.
It is concluded that the rescue breathing apparatus used
should be the automatic resuscitator type with provision
for demand breathing. Such equipment is self-contained and
operates from a pressure cylinder of oxygen. Such apparatus
is not the recycle-rebreathing type but is the full purge
type. The helmet can be removed from an injured miner and
the face mask of the rescue apparatus placed on the miner.
The initial development of any mine as well as that of the
proposed demonstration mine would be in an air atmosphere
under at least temporary ventilation sufficient to meet all
normal safety regulations. The transition from air venti-
lation to an oxygen free pressurized status must be per-
formed safely and at reasonable speed. Likewise, there may
arise certain conditions, particularly in any demonstration
mine, when it will be necessary to abandon the oxygen free
state for the mine.
A new mine during development prior to blanketing can be
intJ1niiY °Perated in an air ventilated condition employing
a 12,000 CFM ventilating fan for the first section. When
it is desired to place the mine in an inert condition,
dampers provided in the gas duct work outside the mine can
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be rearranged so that the ventilating fan can begin to
circulate the mine atmosphere. Inert gas can be supplied
from the inert gas generator system to the discharge of the
circulating fan and an equivalent amount of return gas can
be vented as soon as the required one inch differential
pressure between the mine and outside air has been
established. In the event of an emergency, the dampers
can be rearranged so as to discharge from the ventilating
fan to the atmosphere and to intake into the mine directly
from the outside atmosphere.
Future Planning
Much of the equipment for mining in oxygen free atmospheres
is off-the-shelf; some of it must be modified and some
developed from standard components. The inert atmosphere
adds a severe caution on safety and reliability. The costs
of operating a mine are substantial, and thus any program
to demonstrate the process must utilize the minimum number
of miners, and the minimum supplies and utilities.
Two additional phases are thus proposed for the oxygen free
mining program aimed ultimately at demonstrating the
utility of the process as applied to full scale mining.
Phase II should have as its primary purpose the determina-
tion of the safety, reliability, and suitability of the
key components of suits, life support systems, and communi-
cations gear for mining coal in an oxygen free atmosphere.
The work should be conducted both above ground and below
ground in a portion of an active mine which should be con-
ventionally air ventilated.
It is reasonable for the Phase II program to train and suit
up only two miners but to have these two men operate all
five of the conventional pieces of mining equipment. It is
anticipated that the suits and life support systems employed
would be considerably modified during the course of the
Phase II program. Phase II would also develop the detailed
plans and specifications for all of the components for the
proposed Phase III demonstration mine. It is anticipated
that the Phase II program would cost approximately $700,000
and would take about a year and a half to complete.
Phase III should involve the construction of a demonstra-
tion mine and the operation of a full section with ten men
suited and trained plus their replacements utilizing the
life support systems evolved in Phase II. The Phase III
program should be designed to develop information on the
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productivity and effectiveness of typical miners if the
process is to be ultimately adopted by any significant
segment of the industry. Men presently trained as miners
must thus be the pool from which men would be chosen.
The proposed demonstration mine should employ one loading
machine operator, one cutting machine operator, two shuttle
car operators, one roof bolting machine operator, one coal
drill operator and shot man, two maintenance mechanics, one
general serviceman, one section foreman, and one mining
engineer. Operation during Phase III need be only during
the daylight shift, for one shift each day. Four shifts
per week could be worked with one shift per week being used
for critique and training.
It is anticipated that during Phase III, the demonstration
mine would actually be operated in an inert atmosphere for
a year's time and that the duration of the entire Phase III
program would be two years. The Phase III program would
result in the preparation of the estimates of the cost of
construction and operation of a full scale mine, both for
non-gassy and gassy operations based upon the experience
gained in efficiency of operation as well as in service life
and maintenance of the specialized life support equipment.
It is estimated that the cost of the Phase III program
would be approximately $2,000,000.
Site Selection
The site that should be selected for the proposed Phase II
demonstration mine must be on leases currently available
for operation, must be in a virgin seam in which there has
been no other actual mining activity surface or deep in the
part of the seam to be used, a minimum of 50" of seam
height to allow reasonably uncramped operation, a seam out-
cropping above grade so as to allow drift entries, a non-
gassy seam, and an active mine with working entries within
a reasonable distance so that coal handling facilities,
haulage, utilities and roads may be shared. In addition,
a good probability of producing acid mine drainage during
operation should exist.
Three leases, Red Jacket, Rock House, and Pond Fork, all
within a radius of Holden, West Virginia, belonging to
Island Creek Coal Company, met with the stated requirements.
Field water samples were analyzed and laboratory column
tests were run on samples of refuse from the adjacent active
mines.
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The best site of those studied for the construction of the
proposed demonstration mine is adjacent to the newly
active (July, 1970 production) Pond Fork mine of Island
Creek Coal Company, located in Boone County, West Virginia.
Drainage from the mine area is into the Kanawha River Basin.
A survey of records of other mining activity in this same
seam in this same region, coupled with analyses of samples
of drainage collected within the area, plus the tests run in
the laboratory on columns, indicates a probability of mild
acid drainage from the demonstration mine.
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SECTION IV
INTRODUCTION
Intense public and private interest has been focused in
recent years on the stream pollution and on the dust
levels, and fire and explosion hazards associated with
deep coal mine operation. Testimony in both the House and
Senate on the Water Quality Improvement Act of 1970 empha-
sized the magnitude and importance of the mine drainage
pollution problem and the need to advance the technology
for abating such pollution. Concern over dust and fire
and explosion hazards resulted in the passage of the Coal
Mine Health and Safety Act of 1969, PL 91-173. The
development of new technology to aid in solving simulta-
neously the foregoing problems associated with deep coal
mining is the object of the study discussed herein.
It has been established that the oxidation of pyritic
material associated with coal leads to the development of
iron sulfate and sulfuric acid in the water draining from
the coal mine. Early laboratory studies showed that
exclusion of oxygen from the coal mine would retard or
prevent the formation of acid mine drainage. Further
laboratory studies performed by Cyrus Wm. Rice Division of
NUS CORPORATION in 1968, under FWQA Contract No. 14-12-404,
confirmed that oxygen exclusion from moist pyrites would
result in reducing the production rate of sulfates by over
90% of that produced in air. A program to study the
application of an oxygen free atmosphere to abandoned deep
coal mines is currently under study by the Commonwealth of
Pennsylvania's Department of Mines and Mineral Industries
under Contract No. CR-81 with Cyrus Wm. Rice Division of
NUS CORPORATION supported by FWQA Grant No's WPRD-227 and
14010EFL.
The concept of application of an oxygen free atmosphere to
active deep coal mines originated with J. K. Rice of Cyrus
Wm. Rice Division (RICE) of NUS CORPORATION in 1966. The
concept involved the use of life support systems for the
miners to enable them to operate the mining equipment in a
mine blanketed with an oxygen free atmosphere. Preliminary
conceptual studies indicated the possible success of the
application in not only abating acid mine drainage but in
eliminating both dust inhalation and fire and explosion
hazards from mines. Other possible benefits that could
occur included the elimination of rock dusting and the use
of special explosion proof equipment. In the case of mines
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producing large quantities of methane gas, capture and sale
of this gas would be possible.
The initial ground rules adopted for the feasibility study
were as follows:
1. Maximum use was to be made of equipment that is avail-
able as is or available with minor modification.
2. The sealed mine was to be designed to allow use of all
nitrogen, nitrogen plus methane, or all methane atmosphere
with the oxygen content limited to a maximum of 0.1% v/v.
3. Any proposed demonstration mine was to be located
adjacent to an existing active mine but not connected to it
internally. This would allow the use of the coal handling
and coal preparation facilities of the active mine to handle
the coal produced in the demonstration program.
4. A refuge station was to be located in the sealed mine
near the working face with the refuge ventilated separately
from the outside.
5. Conventional rubber tired mining equipment was to be
used.
6. Sizing of equipment and calculation of support require-
ments were to be based upon using one complete mining crew
working one section, one shift per day.
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SECTION V
MINERS' LIFE SUPPORT SYSTEM (MLSS)
The coal mine must be completely sealed. Oxygen free
atmospheres of either 90% nitrogen-10% carbon dioxide, or
100% methane are proposed to purge and pressurize the mine
to maintain a maximum 0.1% oxygen concentration in the
mine. The recycling of the mine atmosphere, the heat gen-
erated by the mining equipment and the water within the
mine will create a warm humid atmosphere. The minimum
coal seam height, approximately 35 inches, as well as the
design of the mining equipment seats prevents the mounting
of the life support equipment on the miner's back.
The life support system proposed for use in the oxygen
free mine must supply the miner with a cool carbon dioxide
free breathing oxygen uncontaminated by mine atmosphere
with a minimum amount of air leakage from the systems to
the mine so as not to contribute significantly to the
oxygen content of the mine. The system must keep the miner
comfortable in a mine atmosphere at 100% relative humidity
and must not unduly hinder him in his operation of con-
ventional mining equipment. The rebreather section must
be so constructed as to be easily carried by the miner and
mounted onto the mining equipment; it must sustain a miner
for his entire shift plus a 50% safety factor. Where
possible, the system employed should be off-the-shelf and
not require special development. The system must be
extremely reliable yet remain uncomplicated and rugged
To determine the availability of off-the-shelf equipment
and technology, inquiries were sent to various suppliers.
On the basis of the returns, detailed discussions were held
with Arrowhead Products Division - Federal - Mogul Corp.,
ILC Industries, Inc; Litton Systems, Inc, and MSA Research
Corporation.
A trip was made accompanied by a NASA representative to
Cape.Kennedy to the Bendix Launch Support Division to review
the problems involved in maintaining large numbers of life
support systems. Additional information was obtained by
reviewing the In-Fab process developed and tested by the
Universal Cyclops Corporation.
The Bioastronautics Data Book of the National Aeronautics
and Space Administration (NASA-SP3006) was used to establish
the criteria for the breathing system. A requirement of 0.2
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pounds per hour of oxygen and a 1190 BTU per hour metabolic
rate both equivalent to that of rowing a boat for pleasure
were chosen for the average work load. The supply of 70°F
air at 40% humidity provides a 600 BTU per hour evaporative
heat loss equivalent to a sweat rate of 0.6 pounds of water
per hour. An air circulation rate of 15 cubic feet per
minute within the suit is required to provide evaporative
cooling for the miner.
A review of the existing life support systems currently in
use in mines indicates such units are being used primarily
for rescue work. These units consist of face masks and back
packs weighing approximately 35 pounds; they are limited to
a 2 hour use; they are rebreather systems and rely primarily
on compressed oxygen to supply the makeup oxygen to the
rebreather system. This equipment is not satisfactory
because of its 2 hour limit and it would be unreasonable to
expect a miner to wear a 35 pound pack for an 8 hour day.
The life support system should provide 12 hours of oxygen
(50% excess) and should be capable of being mounted on the
mining equipment while supplying the miner with oxygen.
A second consideration was that of a miner wearing a face
mask for 8 hours. In a short period of time, a mask becomes
quite uncomfortable and it is unreasonable to expect a per-
son to work for 8 hours a day, 40 hours a week under these
conditions. In addition, the warm, humid atmosphere expected
in the mine would be very uncomforatable for the miner.
The chosen life support system must keep the man comfortable
as well as supply oxygen. In addition, in order to main-
tain less than 0.1% oxygen in the atmosphere within the mine,
the life support system must be of the closed circuit re-
breather type leaking a minimum amount of oxygen into the
mine.
A review of the literature and work being done by NASA and
other organizations in the space program indicated there are
two basic cooling systems being used to keep the wearer of
life support systems comfortable. One system is to circulate
a cool air throughout the extremities of a completely en-
closed life support suit relying on evaporative cooling to
keep the man comfortable. This is the system used by the
launch support crews at Cape Kennedy and in the Titan Missile
Program.
The second system is to use a liquid cooled garment under-
neath the outer gas tight life support suit. This garment
consists of a series of small tubes knitted into the under-
garment through which chilled water is circulated to remove
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body heat. Using this method there is no loss of body
fluids and the amount of circulated air required to sustain
the man is considerably less (1 cfm versus 15 cfm). The
liquid cooled garment has found considerable use in the
space program due to conservation of body fluids. It adds
additional cost and complexity, however, since pumps and
reservoirs for the coolant and an additional heat exchanger
are required. The undergarment is more bulky and costly as
well.
Investigation
The MLSS includes all components relating to breathing, com-
munications and cooling either worn, carried by the miner
or mounted on equipment. Three approaches were studied in
choosing the equipment for the MLSS. The first was to use
the existing back pack equipment currently being used for
mine rescue work as discussed above. The second was to use
a life support suit similar to those currently being used
by launch support personnel in the Apollo Space Program and
by service personnel in the Titan Missile Program and adapt-
ing to this suit a remote rebreather gas cooling system
utilizing the suit as a breathing bag. The third approach
was to use a helmet sealed at the face or neck, connected
to a breathing vest supplied by a remote source of oxygen
and incorporating the use of a liquid cooled garment.
Existing Mine Equipment
The unit being used in mines today that comes closest to
meeting the demands of this project is the Scott-Draeger
No. 174 (Scott Aviation)* back pack. This is one of the
primary self-contained rebreather systems being used in mine
rescue work. It has a 2 hour rating but it has a 4 hour
capability. The oxygen bottle and CC>2 absorbing canister
could be replaced in the mine refuge station and two changes
would provide for an 8 hour working shift. A supply of
oxygen bottles and CO2 canisters would have to be stored in
the mine. Using this technique, a miner could stay in the
mine for an indefinite period. The disadvantages are as
previously discussed - lack of cooling, face mask irrit-
ation, weight, back mounting, a short operating cycle.
Availability and proven reliability are advantages. Leakage
rate around the mask is variable and no data could be
uncovered.
* Mention of trade names or commercial products does not
constitute endorsement or recommendation for use.
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Full Suit System
A life support system incorporating the complete enclosure
of the miner within a protective suit (coverall type) and
utilizing evaporative cooling for comfort control was part
of the original concept of this project.
A major advantage of the full suit with connected helmet is
that the man would not be required to wear a face mask and
would not have to suffer the discomfort of a sweaty face
within a mask. The full suit is able to provide a control-
led atmosphere over the entire body, head and face to keep
the miner comfortable. As mentioned previously/ there are
two types of cooling systems currently in use in full suit.
The evaporative cooling system provides a large amount of
cool air, a portion (40%) of which goes to the helmet for
both breathing and cooling while the remaining (60%) is
ducted to the various extremities of the body for cooling
only. Two air ducts (tethers) are required to circulate
the air from the external rebreathing module to the suit.
The liquid cooled garment which is worn close to the skin,
as previously described, requires two 1/4 inch tubes to
circulate the water to an external pump and chilling source.
These tubes are in addition to the dual tether required to
supply breathing air to the man and to remove the moisture
from the exhaled breath.
There are several disadvantages to the full suit system.
The suit must be loose since it does not stretch and when
worn is inflated slightly by the need to maintain a slightly
higher pressure in the suit over the ambient atmosphere to
prevent in-leakage. This slight inflation may tend to
hinder the movements of the miner. The use of boots and
gloves may further restrict the miner's ability to operate
his equipment. The possibility of tearing the suit is a
real one and makes a backup breathing system of prime
importance. The tubes required to cool the miner and to
supply breathing air would have to be so located as to not
be in the miner's way when operating the mining equipment.
A full suit incorporating evaporative cooling, would require
15 cfm of air recirculation versus 1 cfm if a liquid cooled
garment with only a helmet were used and only breathing air
supplied to the helmet. The rebreather system blower would
be much larger as would the tethers in the full suit system.
The full suit is more difficult for one man to put on by
himself than the helmet and vest. The full suit system may
require a more involved maintenance and inspection program
by reason of the greater wearing surface and the need for
pressure integrity.
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In spite of these disadvantages to the full suit system,
it's estimated that it's modification for in-mine use would
cost considerably less than the development of the helmet/
vest system and the full suit with evaporative cooling is
available now essentially off-the-shelf from several
suppliers.
Helmet/Vest Systems
This system involves the use of a flight helmet developed by
the Robertshaw Control Company,* Inc., with a breathing vest
developed by the Applied Technology Division of Litton Sys-
tems, Inc.* These in conjunction with a rebreather module,
and a liquid cooled garment would complete the life support
system. No gas tight garment would be required. A wear-
resistant outer coverall would be worn over the vest.
Ordinary shoes and gloves would be used.
The Robertshaw Control flight helmet (AOH-1) is currently
being used by the U. S. Navy. The pilots who have used this
helmet prefer it over others they have used because it is
more 'comfortable and less irritating.
The helmet, hinged at the top swings out at the back and
clamps around the man's neck. A face mask within the helmet
provides a tight seal preventing oxygen leakage from the
helmet. This seal is made of silicone rubber which has
proven to be nonirritating and can be adjusted so that three
sizes of helmets will fit 95% of those required to wear them.
The breathing vest developed by Litton Systems, Inc., is
a double walled vest filled with air which fits snugly
around the man's torso. The oxygen is fed into the vest
and the chest, expanding during normal breathing, forces
this oxygen into the mask. On exhaling, the chest contracts
and the vest expands making room for more oxygen. The
exhaled breath by the use of valving would be recycled to
the rebreating module. The liquid cooled garment would be
worn under the vest and would be used to keep the miner
comfortable.
As mentioned above, normal work clothes could be worn over
the breathing vest and liquid cooled garment, and the miner
would have complete freedom to use his hands and legs. His
trips to the refuge station would be minimized as he would
not have to remove a life support suit to relieve himself.
* Mention of trade names or commercial products does not
constitute endorsement or recommendation for use.
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To complete this system, a remote rebreathing module located
on the mining equipment would be required. This module
would be generally the same as would be required for the
full suit system, however, the amount of air being recir-
culated would be 7% of that required for the full suit
system. In either system the heat rejection and oxygen and
C02 requirements would be the same. The difference in the
two breathing modules therefore, would be that a smaller
blower would be required with the helmet/vest system, the
tether would be smaller, liquid coolant lines, pump and
reservoir would be added, and two heat exchangers, one for
air, and one for coolant would be necessary. The cooling
controls in the rebreather module would be more complicated
in the helmet/vest systems than in the full suit evaporative
system.
Breathing Apparatus
Consideration at first was given to a central system that
could supply the requirements of the entire 10 man section.
The concept envisioned a crew support vehicle carrying the
O2 r C02 units plus the refrigeration unit. This vehicle
would leave the mine with the crew and would be located near
the working face during mining operations. Connections
could be made by hose to reels on each piece of mining equip-
ment similiarily as used for electrical power. The complex-
ity of the hose system, liability to hose failure, and
problems of regulation led to abandonment of the concept in
favor of individual units, one per miner.
Each individual miner thus requires a complete self-
contained rebreather system to furnish oxygen, C02 removal,
and cooling. Since the breathing module can be mounted on
the mining equipment or transport vehicle associated with
the man, the only weight limitation is that a man must be
able to comfortably carry at least the life sustaining com-
ponent into the mine and mount it on his particular piece
of mining equipment.
A review of the available breathing systems indicates that
breathing oxygen can be obtained from the following sources:
liquid oxygen, liquid air, compressed oxygen, compressed
air, special mixtures of oxygen and nitrogen or helium,
potassium superoxide, and sodium chlorate (oxygen) candles.
These sources are currently being used in breathing ap-
paratus generally for short periods of time. In most cases,
the exhaled oxygen is vented to the surroundings. The
choice between these sources is determined by the weight of
the source per pound of available oxygen, the problems
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involved in recharging the breathing apparatus, the ability
to control the rate of air to match metabolic requirements
and the disposal of spent containers, and the limit of 0.2
cubic feet per hour of 02 that can be vented to the mine
atmosphere. The latter requirement rules out both, continuous
purge systems and the use of either liquid or compressed air
since the nitrogen associated with the oxygen must be con-
tinuously purged.
Liquid Oxygen
Liquid oxygen is the most concentrated source of oxygen
available, however, handling liquid oxygen is hazardous and
clean room techniques must be used. The possibility of
fires and explosions due to accidental spilling and contam-
ination in the mine is a real one. Equipment using liquid
oxygen could not be recharged in the mine due to the dusty
conditions. Since the containers for cryogenic oxygen even
though well insulated allow some heat flux, there is a con-
stant bleed off of oxygen that if not consumed by the miner
must be vented to the mine atmosphere. Control of vapor-
ization of liquid oxygen to match demand is complex. While
the heat of vaporization can be used to cool the miner, the
amount of oxygen required for such cooling greatly exceeds
the amount required for breathing and hence must be vented
continuously from the system. The amount so vented greatly
exceeds the 1 cubic foot per hour of air limit. Use of
liquid oxygen for makeup to the rebreathing system requires
a companion device for absorbing C02 from the recirculated
breathing gas. The cost of liquid oxygen in quantity is 15
per pound, making it the most economical of the several
sources.
Compressed Oxygen
Compressed oxygen is readily available in 2200 psig
cylinders. Oxygen at this pressure has a specific volume
of 0.0847 cubic feet per pound thus requiring a cylinder
volume Qf 0.203 cubic feet for the 2.4 pounds specified for
12 hours. Two standard cylinders weighing 13-1/2 pounds
full - 12 pounds empty containing 1-1/2 pounds of oxygen
could be used to meet these requirements. A special cylinder
could also be designed to meet these requirements. Extreme
care must be used in handling the cylinders and cleanliness
must be observed in making all connections. The ability to
store oxygen in cylinders for considerable periods of time
and to easily measure the amount in store by a pressure
gauge is in its favor. The danger of coal dust would limit
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cylinder changes in the mine to emergency only and hence the
full shift capacity would be required in the rebreathing
unit or spare units would need to be used. The ability to
use standard demand pressure regulators for controlling the
rate of use is a major advantage. As with liquid oxygen,
compressed oxygen requires the use of a CO? absorber in the
rebreather circuit. The cost of compressed oxygen in
cylinders is approximately 38.8$ per pound.
Special-Oxygen Nitrogen Mixtures
The use of special compressed oxygen-nitrogen mixtures may
be more desirable than the use of pure compressed oxygen,
from the standpoint of the effects of pure oxygen on the
man. These mixtures would be less hazardous to handle than
pure oxygen and could be prepared at a filling station
outside the mine where adequate safety precautions could be
taken. The composition of the mixture would be regulated
by the leakage rate from the life support rebreather system
so as to maintain the normal 20% oxygen in the rebreather
atmosphere. Maintaining this delicate balance with varying
leakage rates from different suits would present a difficult
control problem. A suit with lower leakage than that cal-
culated for the gas mixture supplied could become depleted
in oxygen below the value adequate for breathing. Costs
would be similar to those for compressed oxygen alone.
Potassium Superoxide
Potassium superoxide is a solid that generates pure oxygen
by the reaction of moisture and carbon dioxide in the air
passing over it. A superoxide canister can deliver 0.34
pounds of oxygen per pound of initial weight. In addition,
the superoxide canister removes moisture, carbon dioxide
and odors. Other oxygen sources as pointed out previously
require companion components for removing these items.
This means that by changing one canister, the system using
superoxides can be completely recharged and no additional
components are required.
Superoxides have a long shelf-life and can be stored within
the mine for extended periods of time for emergency purposes
Canisters can be designed to last up to 36 hours or supply
several men at one time. Since the reaction is exothermic,
additional cooling in excess of the man's metabolic require-
ment is necessary.
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The disadvantage of superoxides is that they continue to
generate oxygen after being removed from the breathing
apparatus. If a canister were changed in the mine, it would
have to be sealed to prevent the oxygen from contaminating
the mine atmosphere. The recommended method for the disposal
of spent superoxide canisters is to immerse them in water
to dissolve the superoxide, thereby forming an alkaline
solution. Disposal of large numbers of these canisters
would present a problem.
A major disadvantage of the superoxides is controlling the
rate of oxygen generation to meet changing requirements of
the miner. Since moisture in the recycled breathing gas
must be controlled for comfort purposes, additional moisture
removal will occur in the chilling apparatus. The balance
between the amount removed and the amount necessary to gen-
erate only the requirement for metabolism would be difficult
to maintain. A still further disadvantage is that once the
canister is used it will generate a set amount of oxygen
dependent on the moisture and carbon dioxide present in the
canister. The reaction cannot be stopped and restarted
again as would be required by a miner visiting a refuge
station. Any surplus capacity left in the canister at the
end of the shift is also lost thereby increasing the cost
of the oxygen. The cost of oxygen supplied by superoxide
in the size canister required is $4.58 per pound of 02•
Oxygen Candles
The oxygen (chlorate) candle is a mixture of powdered iron
and potassium chlorate that when ignited burns to produce
chemically pure oxygen. It is another solid source of
oxygen that has a long shelf-life and could be stored within
a mine if desired. These candles burn at a fixed rate and
the reaction cannot be stopped until it goes to completion
hence their use requires an accumulator system of some sort
to prevent wastage of oxygen generated in excess of
immediate requirements. They can be sized to provide pre-
determined amounts of oxygen, however, and are very compact.
They supply 0.40 pounds of 02 per pound of candle. CO2
absorbers would have to be used with oxygen candles and
additional cooling required above those for metabolism if
they were to be used in the rebreathing module. The spent
candle is a dense sintered material rich in chlorides and
could present a disposal problem. ' Oxygen supplied by
chlorate candles costs $6.25 per pound of 02.
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SPECIFICATIONS
Preliminary specifications for the Miners Life Support Sys-
tem (MLSS) were prepared and sent to those suppliers show-
ing an interest in the project. These specifications were
based on a full suit including gloves and boots capable of
meeting a maximum of 1 cubic foot per hour leakage rate (at
1/4 psig) and incorporating evaporative cooling. Potassium
superoxide was indicated as the most desirable source of
oxygen for the rebreather system. The response to these
specifications contained many helpful suggestions which
were incorporated into the final specifications for the
(MLSS).
One supplier indicated they could provide a suit incorpor-
ating gloves and boots which could meet a zero leakage rate
under the operating conditions of the unit. Another sup-
plier indicated they could meet the leakage specifications
with a suit utilizing cuff and ankle seals rather than
gloves and boots. Meeting the leakage requirement does not
seem to be a problem.
Another supplier questioned the use of potassium superoxide
because of the difficulty in controlling its starting, stop-
ping and oxygen generation rate and recommended the use of
chlorate candles. One supplier submitted a proposal for
the self-contained rebreather system utilizing potassium
superoxide as the oxygen source admitting the difficulties
involved in controlling the operation of the unit and that
it would require considerable development effort.
Final specifications for the Mine Personnel Suit (MPS) and
the Mine Personnel Rebreather System (MPRS) were developed
incorporating the supplier's suggestions pertaining to the
preliminary specifications. A full suit enclosure including
gloves and boots incorporating evaporative cooling was
chosen as the system most readily available and requiring
the least amount of development work. Compressed cylinder
oxygen was chosen as the source of oxygen most readily
adaptable and requiring the least amount of development
effort. The following are the final specifications for the
Miners Life Support System.
Miners Life Support System. (MLSS)
The Miners Life Support System (MLSS) should be comprised
of four basic components, the Mine Personnel Suit (MPS),
the Mine Personnel Rebreather System (MPRS), the Mine
Personnel Emergency Breathing System (MPEBS), and the Mine
30
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Personnel Communication System (MFCS). All components
should be modular in construction for easy maintenance and
a common system must be used throughout the mine.
Mine Personnel Suit (MPS)
The Mine Personnel Suit (MPS) should be a low pressure suit
similar to those used by launch support (NASA) and emergency
ordinance disposal personnel (USN). It must be constructed
in such a manner as to provide freedom of movement as well
as comfort in the sitting and lying positions.
Two styles of suit construction can meet air leakage cri-
teria and each style should be evaluated to determine which
one is best suited for the mining operation. The basic
difference between them being the use of wrist and ankle
seals versus the use of ventilated gloves and boots. All
other specifications for the suits would remain the same.
The basic suit should have rigid seal rings at the wrists
and ankles to provide effective seals for the use of special
boots and gloves. Ventilating air would be blown into these
gloves and boots. The hand protection should be by a two
glove system consisting of a lightweight inner glove and a
heavy exterior glove. Each glove would make an air tight
seal at the wrist so as to prevent air from escaping should
either glove be torn. The two glove system also provides
for the removal of the outer heavy glove to perform delicate
work using the lightweight inner glove. Should the light-
weight glove be torn, the heavy glove can be put on to stop
the air leakage.
The basic suit should have incorporated in it the ability to
install snug wrist and ankle seals capable of meeting the
leakage rate criteria to permit the testing of the suit
while ordinary shoes and gloves are used by the miners.
Ventilation must be provided to the sealed area, while the
hands and feet are exposed to mine atmosphere. This arrange-
ment permits the use of bare hands in the performance of the
work tasks.
The basic suit can meet a zero cubic foot per hour leakage
rate when using special gloves and boots. The modified
basic suit with wrist and ankle seals can meet the 1 cubic
foot per hour leakage rate, but may present the problem of
excessive leakage due to the miners attempting to relieve
possible discomfort at the wrist and ankle seals. The wrist
and ankle seals eliminate the need for special gloves and
boots and the hazard of tearing the gloves.
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The Mine Personnel Suit (MPS) should consist of the assembly
of the following components:
A knitted full length arm and leg undergarment as the first
layer next to the skin.
The second layer, Figure 1, should be a gas impervious suit
of rubber -coated fabric which is light in weight, meets the
gas leakage specifications and has a distribution system
to provide evaporative cooling (similar to the Navy's EOD
suit, Industrial Environmental Protective Suit, Arrowhead
Products SCAPE suit, etc.*).
The third or outer layer, Figure 2, should be a wear resis-
tant work garment designed to protect the gas impervious
layer from excessive scuffing and tearing.
The helmet would be attached by a clamping ring to the middle
garment and be readily separable from the suit.
Special rubber gloves and boots complete the assembly for
the basic style but would not be required for the alternate
style using wrist and ankle seals.
Specifications Mine Personnel Suit (MPS)
These recommended specifications cover the proposed require-
ments for a special clothing assembly or Mine Personnel Suit
(MPS) which will meet the gas leakage requirements, keep the
operator comfortable and be protected from excessive abras-
ions and tearing. A man should be able to don this clothing
without assistance.
All garments are to be sized and graded to fit those in the
95 percentile. The design is to be such that a minimum num-
ber of sizes would be required.
The first or undergarment is to provide complete leg and
arm coverage and is to be made of absorbent knitted cloth to
provide maximum comfort for the wearer and to permit easy
evaporation of perspiration to the circulating atmosphere
in the suit. Standard Long Johns or thermal underwear may
be suitable for this application.
* Mention of trade names or commercial products does not
constitute endorsement or recommendation for use.
32
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UMBILICAL
CONNECTOR
LEAKTI6HT
SLIDE FASTENER
HELMET
HELMET
SEAL RING
COMMUNICATIONS
CONNECTOR
LEAKTI6HT
JOINT
GLOVES
GAS IMPERMEABLE
GARMENT
LEAKTIGHT
JOINT
BOOTS
GAS
FIGURE I
TIGHT MIDDLE
GARMENT
33
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EMERGENCY
REBREATHER
PORTABLE
REBREATHER
OXYGEN
MODULE
FIXED
REBREATHER
CHILLER
MODULE
CO
RADIO
TRANSMITTER /
RECEIVER
OUTER GARMENT
(COVERALL)
BOOTS
UMBILICAL
HOSE
FIGURE 2
MINER IN LIFE SUPPORT SUIT
-------
The gas tight suit or second garment is to be constructed
of a lightweight gas impervious flexible material treated
with an anti-static compound to prevent the buildup of
static electricity. The suit is to be designed such that
it can be put on and all gas tight closures wrist, ankle,
and head can be made by the miner without assistance.
Slide fasteners are to be used for the opening into the suit
and are to be of such design as to maintain the leakage at
less than 1 cubic foot per hour at 1/4 psig. All hand and
feet enclosures or seals are to be designed to maintain the
leakage requirements and to provide maximum comfort.
The gas tight suit is to terminate at the neck area with a
suitable attachment device for mating with a separate helmet
or head enclosure. This device is to provide for rapid re-
moval of the helmet in case of emergency. The seal must be
shielded in a way that sheds accumulations of dust and is
readily wiped clean before resealing.
Ventilation ducts to distribute cool air throughout the
garment and their connecting point on the suit are to be
located so as not to interfere during sitting, lying, or
standing, or in the manipulation of the arms in front of
the body while operating mining equipment.
The total assembly, including the helmet is to maintain a
1/4 psi differential over ambient pressure and must not leak
in excess of 1 cubic foot per hour at this differential.
A maximum of 1 inch water pressure differential is the
specified normal working pressure in the suit. Inflation
of the garment is to be held to a minimum at this pressure
so as not to restrict movement.
Lightweight rubber gloves with the appropriate gas tight
seals are to be provided to permit a high degree of finger
dexterity. A second pair of heavy duty rubber gloves with
appropriate gas tight seals is to be provided for use over
the lightweight gloves to provide a double gas seal in case
the outer glove should be torn.
Heavy duty gas tight steel-toed boots with appropriate gas
tight seals are to be provided.
The exterior work garment is to be made of cotton twill or
similar fabric currently being used for work clothes. This
garment is to protect the gas tight garment from abrasion
and tearing. Scuff pads and special pockets may be required
for tools, supplies, etc.
35
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The head enclosure (helmet) is to be made from a polymeric
material and is to be a dome-type of sufficient size to
permit complete unrestricted head mobility and vision. It
is to be supported by the head and is to turn with head
movements. Standard safety hat specifications are required.
It is to be provided with a mounting bracket on top for a
standard miner's lamp and is to be equipped to receive a
single headset and lip microphone for communication purposes.
Free flow of air is to be provided around the man's head for
cooling and to prevent fogging of the visor. It is to be
equipped with a voicemitter or tin ear over one ear for
sensing in-mine noise. The visor is to be made of a scratch
resistant material treated with lens anti-static compound.
Mine Personnel Rebreathing System (MPRS)
The Mine Personnel Rebreathing System, Figure 3, should
provide breathing oxygen for the miner during his entire
stay in the mine. It should be of such a size and weight as
to be easily carried by the miner and secured to the piece
of mining equipment that he will be operating. The ambient
leakage rate total from the Mine Personnel Rebreathing
System (MPRS) and the MPS should be less than 1 cubic foot
per hour at 1/4 psig differential. All hose connections
are to be quick disconnects with positive shutoff. A
standard configuration must be used throughout the mine.
The MPRS should be a self-contained rebreathing apparatus
utilizing the gas tight suit (MPS) as a breathing bag.
Compressed oxygen should be used as the oxygen source with a
Baralyme CC>2 absorber and mechanical refrigeration for cool-
ing. The use of the gas tight suit as a breathing bag
requires the use of a blower to circulate the air from the
suit through the rebreather and back to the suit. Figure 3
shows the basic components of the system.
Rebreather systems require 2 hoses (tethers) , one to supply
the air to the suit and the other to exhaust the air back to
the rebreather unit. On standard rebreathing apparatus the
length of the hose is fixed and normal breathing maintains
adequate air flow. In this particular application, various
lengths of hoses may be required for various functions. An
8 foot tether should be the standard length and should be
satisfactory to supply the operator while attached to his
piece of mining equipment without presenting too much of a
problem of hose interference while in transit. It would
also permit the miner to set his breathing module on the
floor while inspecting the mining equipment and would give
him some room for movement.
36
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MINE PERSONNEL REBREATHER SYSTEM
CO
I
^ I
FIXED CHILLER MODULE PORTABLE 0? MODULE
SUIT
UMBILICAL HOSE
D. C. BLOWER - 15 CFM
BATTERY
OXYGEN CYLINDER — 30 SCF
2-STAGE DEMAND PRESSURE REGULATOR
COo ABSORBER
BARALYME
CARBON
2
FILTER
SELF CLOSING QUICK DISCONNECTS
CHILLER BYPASS
COOLING UNIT
BYPASS CONDENSER
REFRIGERANT COMPRESSOR
HEATING UNIT
MOISTURE TRAP
FIGURE 3
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In the case of maintenance men, a 20 foot tether may be
required to provide adequate mobility for the performance
of their tasks. Provisions should be made for the insertion
of additional hose and the fan should be sized to maintain
adequate ventilation under this extended tether system.
The final size and configuration of the MPRS will depend
upon the room available for its mounting on the various
pieces of mining equipment. In this regard, off-the-shelf
components should be used for the initial evaluation of the
system. Actual operating experience may require the future
development of more compact equipment, specifically for this
use.
Specifications Mine Personnel Rebreathing System (MPRS)
The MPRS should be comprised of five components or subassem-
blies designed to be rapidly assembled into a self-contained
rebreathing system. It should be compact, lightweight (less
than 60 pounds) and provided with the necessary case and
handles for ease in carrying. It should be designed for
easy assembly and maintenance. All subassemblies should be
modular in nature so that they may be easily interchanged
and all connections must be readily accessible and require
the minimum amount of special tools for changing.
The following subassemblies make up the proposed MPRS.
1. Oxygen source - compressed oxygen
2. Control panel and manifold
3. Air recirculating unit
4. Carbon dioxide canister
5. Air cooling unit
The first four of the subassemblies should be combined at
least initially in a single unit, an oxygen module, while
the fifth comprises the chiller module. The oxygen module
should be portable leaving and entering the mine with the
miner while the chiller module remains on the assigned
equipment. Quick disconnect fittings join the two modules.
Ultimately the size and weight of the chiller module may be
reduced, so that the two may be combined in a single unit.
The oxygen module must function to supply the miner with
oxygen and CO2 absorbing capacity at all times whether at-
tached to the chiller module or being carried by the miner.
Cooling of the miner obviously can only be accomplished
when the both oxygen and chiller modules are joined.
38
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Subassembly 1 - Contains a cylinder of compressed oxygen at
2200 psig containing 2.4 pounds of oxygen. It includes the
necessary high pressure reducing valve, quick disconnect
couplings, hoses, and valves so that the subassembly can be
quickly installed in the rebreather system.
Subassembly 2 - The control panel and manifold contains the
demand pressure regulator, the pressure relief valve, oxygen
sensor, switches, power supply and warning alarms required
to make the completed assembly a safe and reliable rebreather
system. It is to maintain an 0.1 - 0.5 inch water pressure
at the suction of the rebreather blower at all times.
Subassembly 3 - The air circulator contains a 15 cubic foot
per minute blower using a universal AC-DC motor, a recharge-
able battery capable of providing for 2 hours operation of
the blower, and appropriate disconnects, couplings, valves,
hoses, switches, and flow control units as required to
develop a complete and reliable air circulation system
and maintain a maximum 1.0 inch water pressure within the
suit.
Subassembly 4 - The C02 absorber consists of a canister con-
taining Baralyme absorbant along with appropriate hoses and
disconnects, switches, valves, etc., to facilitate rapid
assembly into the completed unit. The canister must be
capable of absorbing 3.3 pounds of CC>2 generated by the
miner in a 12 hour period.
Subassembly 5 - The air cooling unit is comprised of the
necessary mechanical refrigeration and reheating system
with the associated hoses, valves, and disconnects so that
the unit may be quickly assembled into the completed unit.
It is to remove 2,000 BTU per hour (1.0 pound per hour of
water) and when coupled into the completed MPRS to deliver
15 cfm air at 70°F and 40% relative humidity to the suit.
The completed assembly of the five components is to supply
15 cubic feet of air per minute at 70°F and 40% relative
humidity to the suit while maintaining a 1.0 inch water
pressure maximum in the suit when using a 20 foot dual
tether hose 1.5 inches in diameter each.
Mine Personnel Emergency Breathing System (MPEBS)
The Mine Personnel Emergency Breathing System (MPEBS) must
provide oxygen to the miner in case of an emergency where
the MPRS cannot operate or sustain the miner. It must be
carried by the miner at all times and must be designed to be
39
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put into service with the least possible delay. It should
be of the rebreather type making maximum use of the available
oxygen source and must sustain a man for a minimum of 30
minutes.
Two systems were reviewed, each having equal promise. Both
systems were based on having a built-in mouth piece in the
helmet that the miner would bite on and breath through his
mouth as in scuba diving. It will be impractical to use
a nose clamp so the miner must be trained to breath through
his mouth for extended periods of time.
In system A, the exhaled breath would discharge through a
potassium superoxide canister where the carbon dioxide and
moisture would be absorbed and free oxygen generated, and
into a breathing bag. On inhaling, air would be supplied by
the breathing bag. The mouth piece would be valved to con-
trol the various air flows. An oxygen candle would be used
to supply the initial oxygen to fill the system until the
superoxide became effective. Once started the system cannot
be stopped and the canister must be discarded after use.
In system B, the exhaled breath would be discharged into a
carbon dioxide absorbing canister able to absorb 0.14
pounds of CO2 where the carbon dioxide would be removed.
It would then discharge into a breathing bag. Oxygen from
a small compressed oxygen cylinder able to hold 0.1 pounds
of 2200 psig oxygen would supply (via a demand regulator)
the makeup oxygen to the system. On inhaling, the air would
be supplied by the breathing bag and the mouth piece would
control the air flow. Oxygen would be available immed-
iately and the system could be shut off at any time. The
Cp2 absorber would have to be replaced after use, however,
since there is no measure of the capacity remaining. The
oxygen cylinder would be recharged after use.
Of the two systems, A was deemed to be the most compact and
suitable for use in MPEBS.
Specifications - MPEBS
The Mine Personnel Emergency Breather System should be a
self-contained rebreather system worn continuously by the
miner. It must provide 30 minutes of oxygen and it's size
and weight is to be held to a minimum. It is to be located
in such a manner so as not to interfere with the miner while
operating his equipment and must require a minimum amount
of effort to put it in service.
40
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The MPEBS should consist of the following:
A mouthpiece with associated check valves and hose built
into the helmet.
Quick disconnects on the helmet for the hose.
One superoxide canister with a 30 minute rating with a
chlorate candle starter.
One collapsible breathing bag.
The necessary hose to complete the assembly.
All hose couplings should be of the quick disconnect posi-
tive seal type of the same manufacture used for the main
rebreather system. All hose should be lightweight,
flexible and crush resistant.
Mine Lamps
The mine lamp used with the MLSS should be the standard
miners lamp in use today (the MSA Mine Spot* for example).
The MLSS helmet as proposed would contain a mounting
bracket for this lamp. The battery may be the standard
lead-acid battery with inner seals to prevent acid leakage
regardless of the position of the battery. It is proposed
that the present practice in handling, checking and
charging the miner's lamp be used.
Mine Communication System - MCS
Radio transceivers utilizing an in mine radiating antenna
system are proposed to provide the main communication net-
work. Each miner should be equipped with individual
transceivers to provide for communication within the mine.
Each MLSS would thus be equipped with the necessary head
set and microphone and the necessary connections for the
transceiver. See Section VI for details and specifications
for the MCS.
*Mention of trade names or commercial products does not
constitute endorsement or recommendation for use.
41
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Miner's Life Support System Maintenance
The Bendix Launch Support Division has the complete respons-
ibility of maintaining the life support systems used by the
launch support crews (fuel handlers and ground crew) at Cape
Kennedy. During a launch preparation, they can suit 1,000
men a week routinely. The suits are kept in a store room
and checked out and in as required. When checked in, each
suit is washed inside and out in a Freon spray cabinet and
then inspected. All tears and abrasions are patched and the
suit placed in the rack to be used again. Some of their
suits are 5 years old.
The breathing apparatus is cleaned and inspected and the
spent canisters discarded. New canisters and oxygen bottles
are installed and the unit tagged and placed on the shelf
ready for use. Extreme care is used in servicing this
equipment and any part showing signs of wear is replaced.
They do not wait for complete failure of the parts.
A comprehensive daily maintenance program must be estab-
lished for the life support systems proposed as it is
essential to hold malfunctions of the system to a minimum.
Bendix has demonstrated at Cape Kennedy that this reliability
can only be accomplished by a continuing maintenance program
on all components involved in the system. The following
program is an example of the type of maintenance and
safety testing that is recommended.
The major components of the proposed MLSS are the underwear,
gas tight suit (including gloves and boots), helmet, rebrea-
thing apparatus, communication system, the emergency breath-
ing system and the outer garment.
The underwear and outer garment would be issued to the
miner and would be maintained as he is currently doing with
his existing work clothing. All other items would be
maintained in the store room and issued daily to the miners
as required. Each component would have an identification
number and be checked in and out of the storeroom using
this number. In this manner a comprehensive record of the
usage of the equipment can be maintained.
Individual maintenance records would be kept on each piece
of equipment. The information to be logged would include
the day the equipment was used and who used it, the day
it was serviced and who serviced it, what type of service
was required (routine inspection or replacement of parts),
any comments by the user as to the status of the equipment
and a listing of all spare parts used to repair the equip-
42
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ment. The maintenance card would be used to establish pre-
ventative maintenance schedules and indicate when this
maintenance had been performed. For those pieces of equip-
ment requiring routine overhaul, the maintenance record
would be set up to indicate when these overhauls were due.
Included in this maintenance record would be a logging of
the actual time spent in maintaining the various pieces of
equipment.
The maintenance record would be sufficiently comprehensive
that adequate information would be available to determine
the various costs involved in setting up and maintaining
life support systems for use in mining operations. The
record would also serve to point out areas of weakness within
the life support system where additional work is required to
improve the reliability and the economics of the system.
The life support system or any part thereof being returned
to the storeroom would be signed in by the storekeeper and
any comments of the user noted on the checkin slip. These
units would be set aside and completely checked prior to
being put back in the rack for the succeeding day's use.
The following procedures should be used with each particular
item of life support equipment:
1. The gas tight suit should be hung in a cabinet where
hot water containing a detergent can be sprayed inside and
outside of the suit. The suit should then be removed from
a spray cabinet and hung into a drying cabinet where hot
air can be blown through the cabinet to dry the suit. Once
the suit has been washed and dryed, it should be removed
from the drying cabinet and inspected for tears and abras-
ions. Should any wear points appear a patch can be put on
this area to prevent a breakthrough. Any spots of grease
or heavy soiling should be hand scrubbed. Once the suit has
been cleaned and repaired, it should be put on the rack for
the succeeding day's use.
2. The communications gear should be removed from the helmet
and the helmet wiped out on the inside with a wet sponge
containing a detergent. The outside of the helmet should
be washed with a sponge and detergent and the unit dryed.
The helmet should be inspected for scratches on the viser
and other points of damage. The communications equipment
should be cleaned and reassembled in the helmet at which
time the helmet should be placed in the rack for the
succeeding day's use.
43
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3.*-.. The -radio transceiver-should be'checked to see that it
is per forming^ properly.^ and-all? foreign ''Material -remSved
from the ;unit. It should- be taggedy dated-;, arid placed, on
the battery .charging', rack where it can 'remain until it is
checked out the following day. - It is not suggested that :
major maintenance be performed at the mine on the commun-
ication systems. In case of a malfunction of a unit, a
spare unit should be substituted and the malfunctioning unit
sent back to the factory for repair.
4. When the portable oxygen module of the rebreather system
is returned to the storeroom, it should be sent to the
maintenance shop for disassembly and servicing. The oxygen
cylinder should be recharged, and the CO, absorber replaced.
The pressure reducing valve and the chemical regulator
should be checked for proper functioning. The battery
should be recharged. The unit should be reassembled and
placed in the rack for the succeeding day's use.
5. The chiller module would probably be replaced in the
mine by maintenance personnel at regular intervals, and
brought out of the mine for cleaning and testing. Capacity,
refrigerant and power consumption would be checked.
Estimated Cost - Miners Life Support System (MLSS)
In response to the preliminary specifications submitted to
them, Arrowhead Products Division, Federal - Mogul Corp-
oration, Los Alamitos, California; MSA Research Corporation,
Evans City, Pennsylvania; and ILC Industries, Inc., Dover,
Delaware submitted preliminary quotations on the cost of
developing a prototype of the MLSS. Only one quoted on
developing the total MLSS, the other two quoting only on
specific pieces.
In analyzing the quotation, one supplier will develop one
complete MLSS for $27,500 and supply six additional units
for $5,600 each. Another supplier will develop the gas
tight suit only and supply two test models for $30,600 and
2 additional suits for $13,050. These would have to be
mated with a rebreather system furnished by others. The
third supplier will develop and supply four emergency
breathing systems for $750 each and four rebreathing systems
for $16,000 each. These would have to be matched to the
gas tight garment.
44
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In reviewing these costs with the suppliers, they estimate
the mass produced cost of the MLSS to be $1500 to $2000
each after the development of a satisfactory system. The
$2,000 figure should be used in projecting estimated costs
for a full scale mine operation and construction.
45
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SECTION VI
COMMUNICATIONS
Communications in deep coal mines can be divided into two
categories/ local and mine to control station. The former,
or local communication is direct, and either aural or
visual, without benefit of equipment, depending on the
intensity of the mine's ambient sound level. The intro-
duction of miners in life support suits with the attendant
reduction in physical perception introduces a condition
for all miners at all times that is comparable to that in
the worst ambient sound level conditions in a conventional
mine. New methods of communication will thus be required
for men operating in life support suits.
The estimated communication needs in the oxygen free mine
can be broken down into three categories:
1. Determination of ambient mine noises (machinery and
roof) by the miner.
2. Communication between the miners and between miners
and the mine control center.
3. Emergency communication systems from the miners to
outside the mine.
Ambient Mine Noises
The miner normally depends on his hearing to detect the
sounds of roof movement and, by the aid of a test hammer
or probe, the presence of loose rock in the roof. He also
depends on hearing to detect operating conditions of his
equipment. "With the miner enclosed in a life support
suit, provision must be made to satisfy these two basic
communication requirements.
It would be desirable to include an electronic device to
permit the active monitoring of ambient mine noises for
the determination of equipment failures, roof noises,
etc. Ideally, this device would have the following
characteristics:
1. The ability to automatically suppress ambient sound
levels to a consistent and comfortable level for
continuous monitoring.
47
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2. The electronic compression action employed should be
based on the average and not peak values to permit
discrimination of sound peak values.
3. The system should be stereo and not monaural to enable
the personnel to determine sound direction.
Manual gain monaural electronic devices are available that
would achieve part of the above objectives, however, the
complexity of adapting them to the available communica-
tion headsets and the radio communication link to be
discussed later rules them out at least at this time. In
addition, the units available are not suitable in their
available form for the rough usage encountered in the
mine.
Direct sound transmission through a taut diaphragm is used
for voice communication in commercially available face masks
associated with respirators and other breathing apparatus.
Such a diaphragm can be readily installed in the helmet over
one ear if necessary so that both mining equipment and roof
noises may be heard directly by the miner. While this
device in no way mitigates the health problem of high sound
levels, it at least is simple and likely to serve adequately
until suitable electronic devices can be developed.
Interperson Communication
Several communication systems were studied for use in a
mine. The first system employed sound transmission through
electronic speaker phones on each miner; the second
employed hardwire connection through cables; the third
utilized radio transmission from each miner.
An electronic noise monitor contained in the suit to
determine roof and equipment noise could also provide the
basis of a voice communication system for application in
low intensity sound areas. Such transmission could read-
ily be effected through the addition of a standard
amplifier speaker assembly to the miner's communication
system microphone. For machine operators in areas of
high intensity sound in which normal voice transmission
is of limited value, this voice transmission system would
likewise be unsatisfactory.
An electrical cord could be provided to tie the miner into
a machine mounted carrier current communicator or into a
direct wire linkage through the power cable to other such
operators. This would provide direct voice contact of
48
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the machine operators for maximum communication efficiency.
This hardwire communication could also be utilized for
mine to surface communications. It requires, however,
additional wiring, and presents problems for miners not
associated with equipment with trailing power cables.
Mine foreman and maintenance personnel would have to plug
in to local receptacles along the mine walls in order to
communicate. A combination speaker phone and hardwire
system would solve the problem but at the price of
considerable complexity. The required equipment can be
adapted from existing industrial components, however,
the complications of matching and of providing the
multiplicity of cables rules out the two systems at this
time.
A radio communication system should meet the following
criteria:
1. Continuous communication between all in mine personnel
and/or the surface station at discretion.
2. Multiple frequencies to minimize cross talk between
adjacent operating crews.
3. Freedom of miner movement and ability to communicate
in high ambient noise level areas.
4. No dead spots or areas of low signal strength.
5. Availability of equipment suitable for use in the
mine and low initial and maintenance costs.
The currently available commercial radio equipment for
individual use does not uniformly fulfill each of the
above requirements. The available equipment has been
primarily designed for surface use and, hence, has been
subjected to tight restrictions in both available
frequencies and signal purity to comply with FCC regula-
tions. The high frequency operation (VHP) of the
commercially available transceivers is not optimum for
underground use. The result is high initial cost, line
of sight transmission with associated dead spots, and
high signal strength loss. In order to minimize these
latter two conditions, the basic transceiver system has
been modified for underground work through the inclusion
of a support antenna system coupled to a surface re-
transmission station - a so-called "leaky cable" system.
This system is in satisfactory use in subways and is
thus available off-the-shelf.
49
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As the size or complexity of the antenna system at these
high frequencies is in direct proportion to the desired
area of radio coverage, the total coverage of a mine should
not be attempted. The area of coverage should probably be
restricted to the working faces and any active entries or
crosscuts utilized for transportation of personnel or
material. Even with the antenna system, the miner would
have to be in line of sight with the transmission cable for
him to be able to communicate. The cost of the individual
battery powered (rechargeable) transceivers is approximately
$1/200 each. The outside transmitter costs $1,400. The
costs of the cable are approximately $500/1,000 ft. Thus,
the costs of the system are appreciable, however, the
availability and reliability are also important. The
maintenance of equipment of this nature can be estimated
to be between $5 and $12 per unit per month, when the
preventative maintenance is performed by the manufacturer
which would be the practice for most mines. An estimation
of the maintenance costs for the more demanding use in a
mine would be hard to determine because no data exists for
this particular use.
As previously mentioned, the high frequency systems now
available are not considered optimum for subterranean
use. Thus, the design of specialized communications
equipment for mines was also considered. A system based on
the more practical low frequency ranges for better signal
distribution and would be considerably less complex, and
less expensive.
The general reaction of the manufacturers of electronic
communications equipment to the development of specialized
equipment of this type was uniformly negative because of
the relatively low potential market. One of the major mine
supply companies indicated that they had recently completed
a survey of new equipment and techniques in mining in
Europe. The general conclusion was that no new communica-
tion techniques or equipment had been developed or utilized
that did not have an American counterpart. At the present
time, a low frequency radio communications system for
emergency use has been devised by Pittsburgh Consolidated
Coal Company in conjunction with Continental Oil Company
for their own use. Information pertinent to this system
has been requested.
Emergency Communicators
Local emergency communications by a miner in case of radio
failure could be accomplished through the use of small
50
-------
Freon powered whistles or horns that could be easily
carried by the individual person. These units have a
relatively long signal range and would be inherently fool-
proof in use. Signals could be heard through the sound
diaphragm in the helmet. The diaphragm would also allow
short range voice communication between individual
miners.
The emergency mine to surface communication would be best
provided by the use of conventional hardwire telephone
facilities located in the proposed refuge station. The
lines for this communication service together with
emergency station power may be conveyed in mine in covered
ditches or may be conveyed out of the mine through boreholes
and back overland to the mine offices.
Communications Equipment Selection
The only communications system available on which there is
adequate experience is the VHP radio communications system
employing the "leaky cable." An example is the system
offered by Motorola*. The diaphragm in the helmet for the
determination of mine noises should be adopted as described.
The development of an all electronic ambient noise detection
system should be considered for the future, however.
The Freon powered emergency signal devices are available
as boat horns, fire alarm signals, personal alarms,
etc., at reasonable costs and should be considered for
use by each miner.
The preliminary specifications for the complete communica-
tions system are for equipment as offered by Motorola, Inc.,
since theirs was the the only interested response. These
specifications are as follows:
*Mention of trade names or commercial products does not
constitute endorsement or recommendation for use.
51
-------
Manuf acturer:
Model Number:
Frequency:
RF Output:
Plate Input:
Input Voltage:
Dimensions:
Weight:
REMOTE CONTROL BASE STATION RADIO
Motorola Communications and Electronics,
Inc.
C73MHB-1100_R with carrier squelch
136-174 MHZ
110 watts minimum
200 watts maximum
117 vac at 50/60 Hz
22" wide x 30 1/4" high x 8" deep
108 Ibs.
52
-------
ANTENNA CABLE
Conductors:
Dielectric:
Outer
Covering:
Overall
Dimensions:
Weight:
Installation:
Two No. 10 AWG, Solid Bare Soft Copper
Shaped polyethylene extrusion approximately
rectangular, with rounded corners having an
air hole in the center
.035" nominal wall of gray, flame-retardant
polyethylene
1.5" x .800" nominal with rounded corners
.35 pounds per foot, nominal
Cable shall be properly installed on hangers
at least 8" from all metal objects which
shall be spaced no less than 8" nor more
than 10'
Electrical Characteristics:
Characteristic Impedance •
Capacitance
Velocity of Propagation
Attenuation
Dielectric Strength
300 Ohms nominal
4.1 pf. per foot nominal
82%
.7 db/100 feet maximum at 160
MHZ (Factory Test)
.9 db/100 feet maximum at
160 MHZ
This cable is designed to with-
stand a 5,000 volt RMS potential
applied from conductors to a
water bath surrounding the
cable. Since the cable is ex-
tremely buoyant, this test is
conducted on short sample
pieces forcibly held submerged
below water.
Flame
Retardancy:
Reel
Lengths:
Exceeds U/L-83 Vertical Flame Test
For substantial production quantities,
lengths up to one mile can be produced with
reasonable allowance for some lengths as
short as 1,000 feet.
53
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ANTENNA CABLE (Cont'd)
Manufacturer: The Plastic Wire and Cable Corporation
Jewitt City, Connecticut
Contact - K. Strauss, New York City Office
212/597-2250
Figure 4 is a diagram of the communications-antenna system.
54
-------
N
Movable
T Or
Dipole
Extension
Stubs
FIGURE 4
Proposed Communications Antenna System
-------
SECTION VII
GAS BLANKETING SYSTEM
Laboratory studies involving the use of oxygen free atmo-
spheres have indicated that the exclusion of oxygen in a
mine should prevent the formation of acid mine water.
Several different oxygen free atmospheres were tried with
various degrees of success, nitrogen being the most success-
ful (2). Nitrogen is the most plentiful of the gases and
was chosen as the gas to be used. In the case of extremely
gassy mines, the methane itself can be used as the oxygen
free atmosphere. In either case, it is essential that oxy-
gen be prevented from entering the mine to dilute the oxygen
free blanket; 0.1% oxygen is the maximum allowable in order
to prevent the generation of acid mine water.
Since all coal mines generate methane, some considerably
more than others, it is essential that every effort be made
to prevent the collection of a combustible mixture of oxygen
and methane while operating the mine. In an oxygen free
mine, gas locks which would permit personnel and equipment
to enter and leave the mine and which would permit the
continuous removal of coal must be designed so as to elim-
inate all possibilities of those mixtures developing. 5 to
15% methane in air is the explosive range. Below and above
this, combustion takes place at a slower rate. The exclu-
sion of all oxygen would eliminate the possibility of fires
or explosions.
Three sources of nitrogen were investigated, cryogenic,
compressed and natural gas fired combustion gas generators.
The daily volume required (in excess of 500,000 cubic feet
for the proposed test mine), the instantaneous peak require-
ment for personnel and equipment locking, and the high cost
immediately ruled out the use of cryogenic or compressed
nitrogen for small scale use such as in any test mine.
However, on-site cryogenic generation of nitrogen may prove
to be the most economical for a full scale operating mine.
Natural gas fired inert gas generators are used extensively
in the food, chemical and metal finishing industry to
exclude oxygen from the product to prevent spoilage.
Various compositions of gas can be obtained ranging from
99% nitrogen containing traces of carbon dioxide, carbon
monoxide hydrogen and water, to 89% N2, 11% C02 and traces
of water with the price varying accordingly. The latter,
being the most economical (approximately IOC per 1,000 cubic
57
-------
feet depending on natural gas price), is proposed for use
in any test mine. Combustion exhaust gas has an advantage
in that the carbon dioxide present can be used as a tracer
to check for infiltration of the mine atmosphere into the
proposed station, personnel, and equipment locks. Continuous
monitoring of such areas for carbon dioxide would thus
indicate the effectiveness of the locking system.
Blanketing Gas Requirements
After sealing a mine and completing the purging of the oxygen
from the mine, additional blanketing gas will be required
daily to replace gas lost during operation. Personnel and
equipment locking into and out of the mine along with the
removal of the coal from the mine require the major portion
of this makeup gas. Additional gas is required to compensate
for barometric pressure changes and uncontrolled leakage
from the mine and to purge the small amount of 02 leaking
from the life support systems. The latter is estimated at
1600 cf per shift per man based upon 0.2 cfh leakage per
man and a maximum of 0.1% O2 in the mine atmosphere.
The personnel (Figure 5) and equipment (Figure 6) locks and
the coal removal system (Figure 7) are proposed to consist
of small rooms or a hopper between the mine and a refuge
station or outside. The doorways into the rooms should be
equipped with slotted plenums and exhaust fans which will
generate an air curtain across the opening to prevent the
mixing of mine or outside atmosphere with that in the gas
lock. The fans should exhaust to the outside through bore
holes and associated duct work. Blanketing gas under pres-
sure can be piped directly to the gas locks to equalize
the pressure within the lock and to provide an equal flow
from the lock and the mine or outside into the slotted
plenum. Using this principle, there should be no mixing of
mine atmosphere or outside atmosphere with the atmosphere
in the lock and the blanketing gas requirements should be
held to a minimum.
It is proposed for illustrative purposes that the demon-
stration mine be operated one shift per day for 4 days per
week. The fifth day would be devoted to reviewing the prob-
lem areas which may have developed, to making minor equipment
changes and to reviewing safety procedures. Actual full
scale operation in accord with general practice would be
5 days per week, two shifts per day.
58
-------
-NITROGEN
GAS INLET
I-EXHAUST FAN
PER ENTRANCE
(EXHAUST TO
BORE HOLE)
SLOTTED
DUCTS
PRELIMINARY REFUGE STATION
GAS LOCK DESIGN
FIGURE 5
-------
ELECTRIC
ROLLER DOOR
/INERT
XGAS
I-EXHAUST FAN
PER ENTRANCE
(EXHAUST TO
BORE HOLE)
EQUIPMENT AND
PERSONNEL LOCK
FIGURE 6
-------
DUCT
TO MINE
ENTRY
COAL
CONVEYOR
FROM
INERT GAS
GENERATORS
TRUCK
UPPER BIN
(METHANE
ATMOSPHERE)
I" H20 PRESSURE
GATE
LOWER BIN
(INERT GAS
NITROGEN)
H20 PRESSURE
(BATCH FILL
8 DUMP)
GATE
EXHAUST
PLENUM
FIGURE 7
COAL HANDLING CONCEPT
61
-------
The following calculation of blanketing gas requirements for
a demonstration mine are based on the 4 shift per week
schedule of operation and the gas leakage rate in the example
is based on the volume of the demonstration mine anticipated
at the end of 12 months of operation.
Personnel Locking
The section crew would enter and leave the mine once a shift
in a man train passing through the equipment lock. Main-
tenance personnel, safety inspectors, engineers and visitors
would enter through the mine entrance personnel lock. It is
anticipated that every 2 hours, the miners would be relieved
to go to the proposed refuge station for a rest break.
Blanketing gas requirements were calculated on this basis.
It is estimated that the personnel locks in the single
section demonstration mine would be used 100 times per 8
hour shift, each use requiring 1 minute per cycle. Using
for the air curtain a 2,000 foot per minute entrance
velocity into the slotted plenum, and a 1 inch slot 6 feet
high on each side of the opening, each cycle would require
2,000 cubic feet of blanketing gas during the 1 minute cycle
and a 2,000 cfm exhaust fan would be required. Additional
gas would be required for longer cycles. The total_gas
requirements for personnel locking on the above basis for
an /8 hour shift is therefore:
100 cycles X 2,000 cubic feet = 200,000 cubic feet of
blanketing gas required for personnel locking per shift.
Equipment Locking
The man train taking the section into and out of the mine
would require 2 cycles of the equipment lock. It is estim-
ated that one supply train would also be required to service
the proposed single the working section. It would also
require 2 cycles of the equipment lock. One additional
lock requiring 2 lock cycles is anticipated for the boss
cars and maintenance items.
Trips Purpose Lock Cycles
1 Man Train 2
1 Supply Train 2
1 Boss car, Mainten- 2
ance, etc.
62
-------
It is estimated then that the equipment lock will be used
6 times per 8 hour shift. Each cycle is estimated to
require 1/2 minute to open the overhead roller door, 1
minute to enter or leave the lock and 1/2 minute to close
the door or a total of 4 minutes to enter and leave the
lock. A horizontal plenum 10 feet long with a 1 inch slot
using an entrance velocity of 2,000 feet per minute for the
air curtain would require 4,000 cfm of blanketing gas dur-
ing the cyle and a 4,000 cfm exhaust fan would be required.
The blanketing gas requirements for equipment locking in the
demonstration mine example is thus as follows:
4 minutes X 4,000 cfm X 6 cycles = 96,000 cubic feet of
gas required for equipment locking per shift.
Coal Removal
A daily volume of blanketing gas would be required to replace
the volume of coal removed from the mine. An additional
volume of gas would be required to replace the gas lost in
the voids (40%) of the coal when removed from the mine.
Additional gas would be required to purge the coal hopper
of either methane or oxygen prior to or after discharging
coal .
It is estimated that 450 tons per day of coal would be
removed in an 8 hour shift in the demonstration example.
This coal as it leaves the mine has a density of 85 pounds
per cubic foot (60% coal 40% voids) . The volume of gas
required to replace the coal removed is therefore :
450 tons X 2,000 pounds in ,nn . . _
85 pounds per cubic feet = 10,600 cubic feet
* * per 8 hour shift
It is proposed that the coal could be removed from the mine
through a double hopper system, Figure 7. The coal would
discharge through a 3 foot square opening with a slotted
plenum on two sides .
^ would be drawn through a 1 inch slot in the plenum at
the* rate of 2,000 feet per minute and discharged to the
atmosphere. A 1,000 cfm exhaust fan would be required.
As the coal is loaded into the bottom hopper (coal gas
lock) , the upper plenum would exhaust to atmosphere while
blanketing gas would enter the lower hopper. When the
lower hopper is discharged to the truck, the lower plenum
would be exhausted while blanketing gas would enter the
lower hopper. Using this arrangement, no oxygen should
enter the batch hopper.
63
-------
The lower hopper would hold 15 tons of coal which in this
example is estimated to be the capacity of the trucks used
for hauling the coal. During maximum capacity operation,
450 tons f 15 tons per truck equals 30 truck loads of coal
per shift. It is estimated it would take 3 minutes to
load first the batch hopper and then the truck. On this
basis, it will require
30 trucks X 3 minutes X 1,000 cfm or 90,000 cubic
feet of blanketing gas per shift to remove the coal
from the mine.
Barometric Change - Leakage
A barometric change of 1 inch of mercury in 24 hours on a
mine volume of 1,000,000 cubic feet (similar to that in the
proposed demonstration mine at the end of 12 months) causes
a volume change of 34,000 cubic feet. In order to maintain
a constant differential pressure, this volume would have
to be injected or removed into the mine depending on whether
there is a rise or fall in the barometric pressure. A
typical maximum rate of barometric pressure change is 0.2
inches of mercury per 3 hours. Under these conditions,
6,800 cubic feet per hour for 3 hours would be required to
maintain constant differential pressure in the mine in
question.
It is estimated that uncontrolled gas leakage from a mine
could be as much as 10% of the total mine volume per day
(1,000,000 cubic feet). This would include that lost to
barometric pressure changes. This amounts to 100,000 cubic
feet per day of which 34,000 cubic feet would be attribut-
able to volume change resulting from barometric pressure
change. This leakage estimate is based on the abandoned
mine pressurization studies previously referred to (3).
Total Blanketing Gas Requirements
Using the proposed demonstration mine as an example, the
total blanketing gas requirements based on a 1,000,000 cubic
feet mine volume and a-one shift per day operation may be
calculated as follows:
64
-------
Volume Required
Cubic Feet Cubic Feet
Use Per Shift Per Day
Personnel Locking 200,000 200,000
Equipment Locking 96,000 66,000
Coal Replacement 10,600 10,600
Coal Removal 90,000 90,000
Barometric Pressure Change 34,000
Leakage 66,000
Total 396,000 496,000
The blanketing gas generators would therefore be designed
to supply 400,000 cubic feet per shift of blanketing gas.
Blanketing Gas System
The major portion of the blanketing gas must be suppled on
a demand basis in large volumes in a short period of time
to operate the various gas locks. Gas generators sized to
meet the total shift requirement do not have the ability
to meet this instantaneous demand. It is therefore essential
that a means of storing and delivering the blanketing gas
be incorporated into the system.
Gas Holder
A gas holder could perform the several functions desired.
It could be used to maintain a constant positive pressure
in the mine to prevent oxygen leakage into the mine. It
would thus act as the lung of the mine allowing expansion
and contraction during barometric pressure changes. It
could serve as an accumulating tank to supply large volumes
of gas on demand and as a reservoir to supply gas during
outages and startups of the gas generators.
The gas holder should be able to supply the gas requirements
for the two nonoperating shifts and to replace the gas lost
due to leakage and barometric change. 100,000 cubic feet
per day is the estimated requirements for these items in
the stated example of which 66,600 cubic feet would be
required during the second and third shifts. A 100,000
cubic foot gas holder would be satisfactory to meet these
needs.
65
-------
Such a gas holder would be 74 feet in diameter and 26 feet
high and is proposed to maintain a 2 inch water pressure on
the gas. It would contain water seals and the necessary
heating to prevent freezing. Preliminary figures supplied
by a manufacturer indicates an erected cost of $425,000 and
a 10 month delivery date.
Blanketing Gas Generators
As noted in the previous table the gas demand per operating
shift far exceeds the demand for the nonoperating shift and
thus determines the size of the blanket gas generators. In
the example case two units rated at 25,000 cfh each should
be able to supply the 400,000 cubic feet of gas per 8 hour
shift.
Preliminary quotations indicate these generators could cost
$16,000 each. They are normally skid mounted and a minimum
of installation expense would be required. An installed
cost of $20,000 could be used, thus three generators, two
on stream and one standby would cost $60,000.
Each gas generator of the foregoing size requires 300 gpm
of cooling water at 80°F or 200 gpm at 60°F. Well water
at 60°F would be the most desirable water source and it
would require a 600 gpm well. If sufficient well water is
not available, a cooling tower would be required with 10-15
gpm of well water for makeup. Preliminary estimates for a
1,000 gpm cooling tower are $30,000 installed including all
foundations, basins, pumps, tower, and electrical system.
Figure 8 is a skematic diagram of the gas blanketing system
proposed as an example for the demonstration mine, and
Figure 9 shows the general layout of the gas distribution
system in the mine. The following is a summary of the
capital costs associated with the blanketing gas system as
sized for the demonstration case:
Item Cost
100,000 cubic foot gas holder $425,000
3 - 25,000 SCFH gas generators 60,000
1 - 1,000 gpm cooling tower 30,000
Distribution system in mine 25,000
Total $540,000
66
-------
600,000 SCF
PER DAY
TO GAS
LOCKS
OJ
GAS HOLDER
100,000 SCF
2" HO
TO
MINE
TO COAL
BINS
25,000 SCF/HR
EACH UNIT
COOLING
TOWER
IPOO GPM
INERT GAS
GENERATOR
INERT GAS
GENERATOR
FIGURE 8
INERT GAS SYSTEM
DEMONSTRATION MINE
AIR
NATURAL
GAS
-------
To Batch
Hopper
Generator
Gas
Holder
.-Equip-
ment Gas
Lock
Personnel
Gas Lock
Refuge Station
Personnel Gas Lock
FIGURE
Blanketing Gas Distribution System
Demonstration Mine
68
-------
SECTION VIII
DUST AND HEAT CONTROL
The electrical power required to operate the several pieces
of equipment used in mining coal results ultimately in the
generation of heat in the working face area. In normal air
ventilated mining operation, the heat from the electrical
drive motors is released to the air being circulated past
the equipment. In some instances, the heat generated by
the conveyor motor drives is transferred to the coal by
coolers in contact with the conveyor belt.
The amount of air circulated past the working face is
determined in an air ventilated mine by the need to dilute
and sweep away methane gas released by the newly mined coal,
rather than by the need to remove heat from the mechanical
and electrical equipment. Such air movement also serves to
remove dust generated by the coal handling from the working
face. The flow of air for these purposes can vary from
2,000 to 20,000 cfm per section depending on the gaseousness
of the coal seam, the type of mining equipment being employed
and the dust control measures in effect. In the latter
instance, water sprays containing wetting agents are used
particularly on the cutting machine to reduce the amount of
dust generated. Present regulations in the Health and
Safety Act of 1969 require a minimum of 9,000 cfm at the
working face.
Since removal of heat in an air ventilated mine has not
been a consideration in setting up air requirements, measure-
ments of the amount of heat generated, the amount absorbed
by the fresh coal, the amount dissipated to the other parts
of the mine, and the amount finally exhausted to the outside
air were not able to be found. Removal of heat, however, in
the oxygen free atmosphere, whether nitrogen or methane,
becomes the determining factor in designing any gas movement
within the mine.
The amount of heat generated can be estimated from the
installed horsepower of the electrical motors on each piece
of equipment in use at the working face, plus an estimate
of the fraction of the installed continuous duty capacity
that is actually used. The Table 1 shows as an example how
the heat load estimate was derived for the single section
in the proposed demonstration mine. Such a calculation
would be approximately correct for a single section in any
conventionally equipped deep coal mine.
69
-------
TABLE 1
OPERATIONAL HEAT LOAD
Source
Motors
Installed
Installed
Max BTU/hr.
Usage
Factor
Continuous
Load BTU/hr
Cutting Machine
Loading Machine
Shuttle Cars
Roof Bolter
Coal Drill
Feeder Breaker
Conveyor Belt
Boss Cars
Tractor
Personnel
1
1
2
1
1
2
1
3
2
- 250
- 160
- 95
- 30
- 30
- 75
-• 100
2
- 20
HP
HP
HP
HP
HP
HP
HP
HP
HP
636
407
483
76
76
381
254
15
101
14
/
/
r
t
r
r
t
i
t
i
250
200
550
350
350
750
500
270
800
000
0.
0.
0.
0.
0.
0.
0.
0.
0.
3
3
4
4
4
375*
1
1
1
2,447,020
191,000
122,000
194,000
30,000
30,000
143,000
25,000
2,000
10,000
14,000
761,000
*Factor of 0.5 for 75 HP conveyor motor and 0.25 for 75 HP breaker motor.
-------
The 761,000 BTU/hr. continuous heat load is associated with
a section activity that would produce 500 tons per shift of
raw coal. If the efficiencies operating in the inert gas
are lower/ it would be expected that the equipment usage
factor would likewise be lower and thus the continuous heat
load less than the 761,000 BTU/hr. shown in the table.
In considering the heat problem, it must be kept in mind
that the mine atmosphere in a sealed mine will become
saturated with water vapor at whatever temperature is
allowed. Since the miner's suits are proposed to operate
at a maximum of 74°F., condensation on the face plate and
on the suit will result if the mine temperature exceeds
74°F. It is necessary, therefore, that temperature at the
face not exceed this value.
Two alternative methods can be considered for removal of
the foregoing heat load:
1. Rejection to mine atmosphere circulated past the working
equipment
2. Liquid cooling of the motor drives by chilled coolant
supplied to the equipment from outside the mine
Method 1 above has two sub-alternatives, local recircula-
tion by fan through a local chiller unit, and general
recirculation by a fan external to the mine through an
external chiller unit.
Liquid cooling, while possible, has several very serious
disadvantages:
1. Special liquid cooled motors would be required
2. Trailing coolant hoses would add to the difficulties
already encountered by trailing electrical cables and
trailing water spray hoses
3. Pipelines for supply and return would have to be laid
to «the working area from outside the mine
Liquid cooling was rejected on the basis of the foregoing
considerations.
Local recirculation of the mine atmosphere by a local
blower taking suction from portable ducting or from
passages created in crosscuts by temporary stoppings still
requires that the coolant be piped to and from the chiller
71
-------
coil associated with the blower. Also, the blower and coil
and associated piping would have to be moved as mining pro-
gresses.
General recirculation of the mine atmosphere on the other
hand, allows use of the original air ventilating fan with
only a change in duct work to permit return of the fan dis-
charge to the mine. It also allows the chiller unit to be
located outside the mine with minimum piping all of which
would be permanent. General recirculation would require,
however, that passageway for the gas be maintained by
stoppings from the entry back to the working face.
On the basis of the above considerations, local recircula-
tion of gas was rejected in favor of general recirculation
utilizing the ventilation fan installed external to the
mine for the initial air ventilated portion of the opera-
tion of a mine planned for a subsequent oxygen free
atmosphere.
When looking at the problem of heat transfer to the mine
walls, it is necessary to look at the relationship
Q = K xAT. It is obvious under a steady application of
A L
heat, that as L increases, that is, the surrounding strata
is heated up and the linear path for conduction increases,
the heat flux will decrease. The mine walls become in
effect an infinitely thick insulation albeit a poor one.
This situation is entirely analogous to pipelines buried
in soil. After a period of time, the rejection of heat
to the mine walls becomes negligible as can be seen when
L becomes infinitely large. Heat flux versus time is thus
a straight line log log plot.
In an air ventilated coal mine, the mine walls appear to
serve as an accumulator taking heat from the outside venti-
lating air in the summer and rejecting heat to the incoming
air during winter. How much of the heat generated by the
mining equipment eventually finds its way to the outside
atmosphere is not known. On the basis of the above general
considerations, it was decided to disregard any rejection
of heat load to the mine walls since any error in this
decision results in the need to transfer less heat by out-
side refrigeration.
In calculating the amount of heat rejection to the outside
atmosphere that will be required when all of the mine
atmosphere is recirculated, consideration can be given to
the heat taken up by the raw coal as it is mined and
72
-------
conveyed through the mine to the outside. On the basis
of 500 tons per shift at normal efficiency, and assuming
a maximum mine temperature of 74°F. for the return gas,
it appears reasonable to assume that the coal mined will
be raised from 55°F. to 65°F. by the time it discharges
to the hopper outside of the mine. The amount of heat so
absorbed would be 375,000 BTU/hr. The heat remaining
that must be rejected by mechanical refrigeration of the
recirculating gas is thus approximately 400,000 BTU/hr.
The amount of mine gas to be recirculated to provide the
required cooling at the working face must still be based
on the amount of heat to be removed at the face less that
qoinq directly into the coal as a result of energy
conversion. If one-third of the cutting machine energy
is assumed to go into raising the coal temperature, then
696.000 BTU/hr. remain to be removed by the gas. If it
is assumed that the gas arrives at the face at 55°F. at 100%
relative humidity and is heated to a maximum of 74 F. at
100% relative humidity (moisture from coal sprays plus that
from roof, floor, and walls), then a maximum of 12,000 cfm
will be required for one section in a conventionally
equipped mine.
It is believed that substantially more heat than the 64,000
BTU's assumed above will go directly into the coal as a
result of the mechanical work performed on it, and thus the
12 000 cfm circulating gas should be more than adequate to
provide the required cooling at the maximum expected
capacity of the equipment without exceeding the 74 F.
maximum gas temperature permitted.
Figure 11 shows in diagrammatic fashion the scheme developed
as an example for the proposed demonstration mine on the
basis of the foregoing discussion. The mine atmosphere
would be conveyed in ducts external to the mine through
the ventilating fan (12,000 cfm) through the chiller coils,
and back to one of the entries to return to the working
face. Dampers in this duct system would permit changeover
from recirculating mine gas under a sealed system to
exhausting the mine atmosphere to the outside air while
drawing in fresh outside air through the passageway direct
to the working face. Such an arrangement would allow the
atmosphere in the mine to be changed rapidly in the event
of an emergency that required returning the mine to an air
ventilated status.
The chiller coil located in the duct work external to the
mine would be supplied with chilled water from a Freon-water
heat exchanger. The coil would also have a provision for
73
-------
recycled spray water to supplement the 1 gpm of condensa-
tion as an aid in flushing dust from the condensing
surfaces. A total of 50 tons of mechanical refrigeration
would provide approximately 50% excess capacity over the
expected load per section. This excess capacity should be
more than adequate to compensate for any reduced heat
pickup by the mined coal from that estimated above. The
mechanical refrigeration would reject heat to the atmosphere
using a Freon to air condenser, the latter arrangement
being much preferred and much less costly to install at this
size unit than a water cooled condenser with a cooling
tower. The expected installed cost of the unit is $50,000
to include the coils and sprays, as well as the pumps,
refrigeration unit, and switchgear. Power consumption is
estimated at 50 KW total at maximum load which at $0.01/KWHR
is $4 per day based on single shift operation for the single
section.
The general recirculation of gas also solves or at least
does not worsen the dust problem at the working face. The
12,000 cfm provided at the face should move dust from the
equipment operation equally as well as it does in a conven-
tional air ventilated mine using water sprays on cutters,
face drills and loading machines. The heavier dust fractions
will settle out in the passageways followed by the return
gas to the outside of the mine. The lighter dust fractions
may or may not remain to reach the chiller coil. No data
could be found on dust loads of mine ventilating fan
exhaust. Such information may be obtained in the future
on new mines with relatively short air passageways similar
to the condition existing in the proposed demonstration
mine.
Dust that reaches the chiller coil will be removed to some
degree by the wet surfaces and condensation taking place.
The spray water can provide one more step of scrubbing if
required. It is possible that data would show the need
for further scrubbing and, if so, such equipment can be
added at a later date.
It is concluded that the system proposed will be adequate
for dust control without special dust removal equipment and
that such can be added readily at a later date if required.
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SECTION IX
IN MINE SYSTEMS
Development of a new drift mine for operation in an oxygen
free atmosphere should start as any ordinary mine with
normal air ventilation. It is proposed that the construc-
tion of a demonstration mine proceed in the same fashion.
Entries typically should be driven on 60 feet centers and
crosscuts on 80 feet centers. The mine most probably
would be developed to the third set of crosscuts in normal
atmosphere and the first waystation or refuge station
driven into the right rib of the right heading to intercept
two 10 inch boreholes, Figure 10, drilled from the surface,
Figure 11. The sequence of mining would typically be as
follows: the roofbolter would go into the right side entry
and secure the top by drilling holes on a 5 feet square
pattern and installing steel roof bolts. This unit would
move to the left or next entry and be followed by the
cutting machine, which in turn would be followed by the
coal drill to drill and shoot or break the coal loose for
the loader to move in and clean up the material.
Waystation or Refuge Station
The refuge station suitable for single section use should be
developed under 20 feet wide and approximately 40 feet into
solid coal as in Figure 11. This area should be graded to
provide about 7 feet of height in order that the miners
could stand upright at all times. This area should be
sealed off from the remainder of the mine by concrete
blocks plastered with cement and bituminous based materials
to insure its being gas tight. Entrance to the refuge
must be through a gas lock. The refuge station should
maintain a normal atmosphere at normal pressure by ventila-
ting through the previously mentioned two 10 inch boreholes
from the surface as in Figure 10. All necessary materials
and supplies must be available in the refuge station to
insure survival for an extended period of time (days).
Sanitary toilet facilities must also be available along
with appropriate safety and rescue equipment. Emergency
suit repair equipment as well as spare miners' life support
systems and communications equipment must also be main-
tained in the refuge.
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COOLING TOWER
INERT GAS GENERATOR
INERT GAS
STORAGE TANK
COAL FACE
\v\\\\\\\\V\V\\\\\\\A\\\\\\V\\v\\\\.
AIR
LOCK
INERT GAS LINE
|\ \ \ \ \ \X\\\\ \\ \\ \\/\\ \\\\\\V\\\V\\\\W
WAY
STATION
COMMUNICATION LINE'
7
EXTERNAL
SEALS
CUTTER
FIGURE 10
SECTION OF MINE AND COVER
EQUIPMENT
LOCK
PERSONNEL
LOCK
-------
N
EXPLOSION DOORS
DUCT
.
COAL CONVEYOR
AIR CONDITIONER
CIRCULATING FAN 12.000 CFM
i
EXPLOSION DOORS
ADDERS
EQUIPMENT AND
PERSONNEL GAS
LOCK
FMFRGENCY AIR INTAKE
PERSONNEL
DOOR
rinniMTFRWFlRHTED DAMPER
EQUIPMENT
FLOW OF ATMOSPHERE SYSTEM
NO. I WAY STATION
TWO 10" VENTILATION HOLES
FROM SURFACE
EXHAUST FAN ON ONE
GAS LOCK*
FIRST WEST
TEMPORARY STOPPINGS (TYPICAL)
FIGURE II
PLAN OF DEVLOPMENT AND ATMOSPHERE CONTROL SYSTEM
-------
Gas Locks
Gas locks provided for personnel entry into the refuge
stations and for personnel and equipment entry and egress
from the sealed mine proper should be constructed with two
doors interlocked so that only one door will open at any
time. One of the entries to the mine must be equipped
with a large gas lock designed to allow the largest piece
of mining equipment to be moved through the lock for egress
from the mine for major maintenance. It must also be
equipped with a smaller personnel gas lock to allow miners
to enter and leave the mine, as illustrated in Figure 10.
Ventilating System
A second entry should contain the ventilation fan, as shown
in Figure 11, which should be ducted back to the conveyor
entry for recirculation of the oxygen free atmosphere during
operation under such oxygen free conditions. Circulation
can be at a much reduced rate, probably closer to 12,000
cubic feet per minute for the five face section, however
compared to 50,000 CFM for air ventilation. Cooling coils
must be used in the ventilation duct outside the mine as
previously discussed in order to remove the heat from the
circulating gas, such heat being picked up from the opera-
tion of the mining equipment. The inert atmosphere for the
proposed demonstration mine as described earlier is the
exhaust from the combustion of natural gas.
Materials Removal
A third entry should have the conveyor belt installed in it.
The belt as it emerges from the mine should be contained in
a duct extending from the entry to the top of an external
coal bin. This coal bin, as discussed in the section on Gas
Blanketing, should be a two section bin with a gate valve
between each and at the exit from the lower bin. Coal
should discharge into the upper bin under the atmosphere of
the mine, which atmosphere should be maintained within the
duct and in the top of the bin. Inert gas should be supplied
to the lower bin to purge it during such time as coal is
transferred from the upper bin to the lower bin. Inert gas
should also be supplied to the lower bin when coal is being
discharged from it into the truck for transport to the
preparation plant. It is possible to use tracked coal cars
within the mine to carry coal from the working sections to
a loading point for the conveyor. In a single section mine
such as the proposed demonstration mine, this would be
impractical. The conveyor belt thus should extend along one
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entry to the crosscut adjacent to the working faces where a
feeder breaker would be installed.
Mine Lights
The problem of lighting within an oxygen free mine was
simplified when a design for the miner's helmet was selected
which permitted the miner to swivel his helmet with the
turning of his head. Such an arrangement allows the present
mine lamp to be used and attached as at present, as
described in the section on Miners' Life Support Systems.
The sealed beam lights currently used on permissive mining
equipment are satisfactory and should continue to be used.
Mining Equipment
Conventional rubber tired mining equipment should be used
in the proposed demonstration mine, though the process
should be applicable to continuous as well as long wall
mining. The equipment should have the necessary electrical
connections and supports to carry the Miner's Rebreather
Systems. All equipment for use in the proposed demonstra-
tion mine should be powered by 440 volts A.C. with the
exception of the shuttle cars and supply and personnel
carriers. The recommended 250 volt B.C. supply for the
shuttle cars should be provided by a 112 1/2 KW rectifier.
The supply tractor, boss cars, and personnel carriers
should be powered by conventional 96 volt batteries. An
oil circuit breaker should be installed to insure safe
conditions on the section. All power should be cut off if
the breaker is tripped.
In the proposed demonstration mine, the loader and feeder
breaker should be mounted on caterpillar-type conveyances
and all other mining equipment mounted on rubber tires.
A complete list of all inside mining equipment for the single
section in the proposed demonstration mine is as follows:
cutter, loader, two shuttle cars, roof drill, coal drill,
feeder breaker, conveyor belt, complete set of electrical
components for supply of the face equipment, three boss cars,
two personnel carriers, and a supply tractor and supply
car.
While the mining equipment recommended for the proposed
demonstration mine would be approved permissive type, the
electrical systems on equipment for future full scale mines
operating in a methane atmosphere must be specially designed
for the purpose. Provision must be made in such instances
to either pressurize with nitrogen gas a sealed electrical
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system or to provide an enclosed but unsealed system able
to be quickly purged completely using nitrogen gas every
time the equipment passes through a gas lock.
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SECTION X
PERSONNEL PROGRAM
If new or existing mines in the bituminous coal industry are
to utilize the oxygen free atmosphere process to any signif-
icant extent, it is necessary that at least initially men
presently trained as miners be the pool from which men would
be chosen for training for operation in such mines. Discus-
sion with National Aeronautics and Space Administration was
held on their experience with skilled labor at Cape Kennedy.
Island Creek's experience with miner training was considered.
It is concluded that present job specifications should be
employed for each of the men involved, supplemented with
thorough physical examinations and only sufficient psycho-
logical testing to determine that the individual would be
able to operate in a life support suit.
Conventional deep mines as well as the proposed demonstra-
tion mine employ loading machine operators, cutting machine
operators, shuttle car operators, roof bolting machine
operators, coal drill operators and shot men, maintenance
mechanics, general servicemen, section foremen, and mining
engineers. While many conventional mines are operated two
shifts per day, it is recommended that the proposed demon-
stration mine be operated only during the daylight shift,
for one shift each day. In this latter instance, four shifts
per week should be worked with one shift per week being used
for critique and training.
The following detailed job descriptions which are typical
for the foregoing personnel and should be used for the
proposed demonstration mine personnel as well. Each of the
following job descriptions include as required, the function,
responsibility, activities, relationship to other personnel,
and authority:
Loading Machine Operator
Function
As a member of the mine production force, he receives his
work assignments from the section foreman. In a safe and
orderly manner, he loads coal that has been cut and shot
from the face. He loads this coal onto a shuttle car.
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Responsibility
He is accountable to the section foreman.
He must perform his assigned duties in a manner as to insure
the safety of his fellow workers and the safety of the mine.
He is charged with the responsibility of reporting to his
section foreman any repairs that are needed to be made to
his machine.
Preproduction Activities
He is to find out from his section foreman into which work-
ing place he is to go.
He is to check his loading machine to see if it is in
operating condition. After determining that his machine is
in operating condition, he then directs someone to put the
power on the machine.
Production Activities
Tram the loader to the designated place as instructed by the
section foreman.
Check the working place for safe conditions. He is to check
the roof for safety. Notify the section foreman as to the
safety of the working place.
Break the cut on center line of roadway. Load the cut coal
into a shuttle car.
When cut coal is loaded, he re-checks the top and sets
safety posts as needed.
Tram the loader to the next place as designated by the
section foreman, and repeat the production cycle.
Cutting Machine Operator
Function
As a member of the mine production force, he receives his
work assignments from the section foreman. His function is
to under cut coal in places as they become available to him,
according to rib lines as marked by the section foreman.
He is to cut the coal in a manner so as to insure the maxi-
mum loadability.
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Responsibility
He is accountable to the section foreman.
He must perform his assigned duties in a manner as to insure
the safety of his fellow workers and the safety of the mine.
He is charged with the responsibility of reporting to his
section foreman any repairs that are needed to be made to
his machine.
Preproduction Activities
He is to find out from the section foreman into which work-
ing place he is to go.
He is to check the cutting machine to see if it is in
operating condition, and see if the cutter bar has sharp
bits in it. After determining that his machine is in
operating condition, he then directs someone to put the
power on the machine.
Production Activities
Tram the machine to the working place that the section fore-
man has designated.
Check the working place for safety conditions. He is to
check the roof for safety and make a gas test with a gas
lamp. Notify the section foreman as to the safety of the
working place.
Sump the cutter bar into the right side of the face. Cut
across the face. Pull machine back and put a bar lock on
the bar.
Re-check the roof for safety. Make a gas test with a gas
lamp.
Tram the machine to the next working place. Check the cable
for*proper length, and see that it is out of the roadway.
Repeat the production cycle.
Shuttle Car Operator
Function
As a member of the mine production force, he receives his
work assignments from the section foreman. In a safe and
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orderly manner, he is to transport the coal by shuttle car
from the loading machine at the face to the loading point
inside the mine. His function at certain times may be that
of hauling supplies from the supply hole to the face.
Responsibility
He is accountable to the section foreman.
He must perform his assigned duties in a manner as to insure
the safety of his fellow workers and the safety of the mine.
He is charged with the responsibility of reporting to his
section foreman any repairs that are needed to be made to
his machine.
Preproduction Activities
He is to find out from his section foreman into which work-
ing place he is to go.
He is to check his shuttle car to see if it is in working
condition. After determining that his machine is in
operating condition, he directs someone to put the power
on the machine.
Production Activities
He moves his machine to the working place.
His machine is loaded with coal by the loading machine. He
transports this coal to the loading point. He unloads the
coal onto a belt feeder or an elevator, which in turn loads
the mine cars.
He returns to the loading machine and repeats this cycle.
Roof Bolting Machine Operator
As a member of the mine production force, he receives his
work assignments from the section foreman. In a safe and
orderly manner, he roofbolts and/or timbers the roof to
prevent roof falls; and to further insure the safety of the
working place.
Responsibility
He is accountable to the section foreman.
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He must perform his assigned duties in a manner as to insure
the safety of his fellow workers and the safety of the mine.
He is charged with the responsibility of reporting to his
section foreman any repairs that are needed to be made to
his machine.
Preproduction Activities
He is to find out from his section foreman into which work-
ing place he is to go.
He is to check his roofbolting machine to see if it is in
operating condition. After determining that his machine is
in operating condition, he then directs someone to put the
power on the machine. He then checks to see if he has
enough supplies to last the shift and advises the section
foreman of his supply needs.
Production Activities
Move the machine to the working place as assigned by the
section foreman.
Examine the roof and ribs for safety condition. Set safety
posts as determined by mine management in accordance with
safety regulations.
He proceeds to drill the roof to pre-determined depths and
install roofbolts into the drilled holes. The roofbolting
pattern is based on a roofbolting permit obtained from the
Department of Mines.
He moves his machine to the next working place and repeats
the production cycle.
Coal Drill Operator
As a member of the mine production force, he receives his
work assignments from the section foreman. As a coal drill
operator, his function is to drill all coal that is avail-
able to him as directed by the section foreman.
Responsibility
He is accountable to the section foreman.
He must perform his assigned duties in a manner as to insure
the safety of his fellow workers and the safety of the mine.
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He is charged with the responsibility of reporting to his
section foreman any repairs that are needed to be made to
his machine.
Prepreduction Activities
He is to find out from the section foreman which working
place he is to go.
He is to check his machine to see if it is in proper
operating condition. A check should also be made to see if
the bit is sharp. He then directs someone to put the power
on the machine.
Production Activities
He is to move the machine to the working place that is
designated by the section foreman.
He then checks the working area for safety conditions. He
makes a gas test and checks the roof. He is to advise the
section foreman of any unsafe conditions.
He proceeds to drill as many holes in the face as the drill
pattern requires. This pattern is designated by the mine
management to insure the safest way of producing the maximum
loadability from the coal that is shot from the face. He
pulls the machine back from the face. He then takes another
gas test with his gas lamp. He reports any unsafe condition
to his section foreman.
He proceeds to the next designated working place and repeats
the production cycle.
Maintenance Mechanic
Function
As a member of the mine maintenance force, he is accountable
to the Chief Electrician and is responsible for carrying out
the following operations, activities and assignments:
Maintain all mine equipment in a safe and efficient manner.
Receive reports on mechanical, electrical and hydraulic
failures and make necessary arrangements to correct these
conditions.
Responsibility and Authority
The maintenance mechanic is responsible for and has the
authority to act in carrying out his assigned activities:
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He will utilize his assigned tools, facilities and available
services, in the most effective manner possible to complete
scheduled work as assigned.
He will make sure that any personnel assigned to him, in the
form of a helper, is thoroughly trained in safe and effective
methods and procedures and will report any deficiencies.
He will see that all preventive maintenance measures are
carried out as scheduled.
He will attempt to minimize time loss due to breakdowns.
He will report all maintenance measures and activities to
the Chief Electrician.
He will make all necessary repairs to all equipment assigned
to him and will assure that all machinery is functioning
properly.
Relationships
The maintenance mechanic will observe the following rela-
tionships :
The Chief Electrician
He is accountable to the Chief Electrician for the fulfill-
ment of his assigned duties.
Others
He will conduct no other relationships.
Time Clerk
Function
To maintain time cards for the payment of union employees
in accordance with the contractual wage rates. To maintain
records of mine inventories.
#
Responsibility and Authority
Responsibilities
He is accountable to the Division Controller for the proper
performance of the following duties:
To maintain records, receive and disbursement of mine
inventory including:
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Roofbolts
Timbers
Rockdust
Lubricants
Spray oils
Other necessary supplies
To maintain records of tonnage and costs.
To maintain good relations with our suppliers.
To conduct business within established policies at
all times in an ethical manner.
Authority
Authority is granted to commensurate with assigned duties.
Relationships
He has a liaison relationship with the Mine Superintendents
and other Staff and Operating Personnel to secure and impart
information of mutual benefit.
Section Foreman
Function
As a line member of management, he is accountable to the
Mine Foreman and is responsible for carrying out the follow-
ing operations and activities:
Producing quality coal to objective standards;
Safety of men and equipment on section; maintaining
section to specification of Federal, State and Company
policy;
Maintaining section on proper projection;
Ordering supplies for future use;
Keeping the Mine Foreman advised of conditions of
section to enable proper planning; and
Other similar activities as assigned by the Mine Fore-
man.
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Responsibilities and Authority
The Section Foreman is responsible for and has the authority
to act in carrying out activities, programs and schedules as
approved by the Mine Foreman.
Responsibilities
He will utilize his assigned equipment, facilities and
personnel in the most effective manner possible to
assure maximum use of all of his facilities in the
production of quality coal.
He will make sure that all personnel assigned to his
section are thoroughly trained in safe and effective
methods and procedures and will follow-up to assure
that these are followed at all times.
He will instruct members of his crew in preventive
maintenance of his assigned facilities:
To minimize production loss due to breakdowns; and
to extend operating life of assigned facilities.
He will investigate and report on grievances and
complaints and will counsel and advise his crew to
maintain good will and maximum effort.
He will take all practicable steps to assure that
foreign matter such as slate, metal, wood and rubbish
are not mixed with coal sent to the preparation plant.
He will conduct weekly on-the-job safety meetings and
maintain an adequate safety program, including a
thorough investigation of injuries and safety incidents,
a complete "job observation" at least monthly, and
planning for effective accident prevention. This.will
include provisions for good housekeeping on his
section and all other areas under his supervision. He
will contribute to cost reduction in his operations:
By improving labor utilization;
By eliminating waste in materials and supplies;
By contributing projects to his mine's cost improve-
ment program.
He will maintain all required records in good order and
will issue operating and production reports as scheduled,
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Authority
He will recommend to the Mine Foreman any unusual mainte-
nance, improvements or replacements which may be necessary
to maintain current or anticipated production requirements.
In consultation with the Mine Foreman, he will consider and
make recommendations for the following:
Hiring, promotion, demotion, transfer or dismissal of
personnel; and
Operation of his assigned activities in accordance with
Company policy.
Relationships
The Section Foreman will observe and conduct the following
relationships:
The Mine Foreman
He is accountable to the Mine Foreman for the fulfill-
ment of his assigned activities and schedules, and for
the proper interpretation of his responsibilities and
authority.
Other Mine and Staff Department Heads
He will consult with the Mine Foreman as to the extent
of advice and assistance that may be required.
In no way will he assume, nor will he be delegated,
any function, authority, responsibility or relationship
specified as belonging to another member of management.
Others
He will consult with the Mine Foreman as to the estab-
lishment of other relationships considered necessary
for the proper accomplishment of his function.
Mining Engineer
Function
As a staff member of management is accountable to the Chief
Mining Engineer for carrying out the following operations
and activities:
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Advise and assist the Chief Mining Engineer in conduct-
ing the Company's prospecting activities and in
coordinating mining engineering functions.
Responsibility and Authority
The Mining Engineer is responsible for and has the authority
to act in carrying out activities, programs and schedules as
approved by the Chief Mining Engineer.
Responsibilities
He will assist the Chief Mining Engineer in the develop-
ment of broad mining engineering objectives, policies,
programs and procedures;
He will assist the Chief Mining Engineer in planning
current and long-range development of currently operat-
ing mines including overall mine layout, projections,
ventilation, roof control, haulage and drainage, making
recommendations on selection and utilization of mining
equipment;
He will follow-up authorized mining engineering projects
as directed by the Chief Mining Engineer;
He will prepare current production and mine life graphs
as directed; correlating this information with future
mine development programs as directed by the Chief
Mining Engineer;
He will assist the Chief Mining Engineer in scheduling,
making or having made regular property inspections;
He will supervise diamond drilling and churn drilling;
interpret analyses of core and channel samples, and
report information received, making necessary recom-
mendations to the Chief Mining Engineer;
He will direct the activities of the drafting operation
in the mapping of specially assigned mine workings.
Authority
In consultation with the Chief Mining Engineer, he will con-
sider and make recommendations for the operation of his
assigned activities in accordance with established company
policies, and advice to his subordinates in the proper use
or conformance with various policies and procedures.
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Relationships
The Mining Engineer will conduct the following relation-
ships:
The Chief Mining Engineer
He is accountable to the Chief Mining Engineer for the ful-
fillment of his assigned activities and schedules, and for
the proper interpretation of his responsibilities and
authority.
Psychological Testing
In the, selecting and evaluating of personnel for mining in
an oxygen free atmosphere, it must be kept in mind that the
requirements must not be in excess of those currently used
for the present employees in modern conventional mines. It
is envisioned that this mining technique, once developed,
may be broadly used in the industry, it is necessary,
therefore, that the basic requirement for employees remain
essentially the same as they are now so as to make it
possible to retain and utilize existing personnel.
The fact that miners are used to cramped quarters and to
carrying the miner's lamp, rules out claustrophobia and
the objection to some additional weight in a majority of
the cases. It is to be expected, however, that in a few
instances, the close confinement within the Miner's
Personnel Suit (MPS) will be objectionable to some people
and they will not be able to tolerate this confinement.
The only practical test to evaluate this aspect is to
actually have the subject wear the MPS and observe his
reactions and comments. The Bendix Launch Support Division
at Cape Kennedy uses this technique to screen personnel to
determine those mentally suited to tolerate the close con-
finement within this type of enclosure for extended periods
of time.
All miners have already been instructed in the use of the
self rescue pack and many of them have had experience with
the self contained rebreather back packs currently being
used in mine rescue work. They have a basic understanding
of the methane-oxygen relationship as well as the carbon
dioxide problem existing in the mine and their effect on
the miner and the mines' operation. In this respect, they
already had some of the basic knowledge required for the
understanding and use of the Miners' Life Support Systems.
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Universal-Cyclops in their In-Fab Program made extensive use
of psychological testing in their selection of personnel to
be used on the project. They came to the conclusion that
the best technique to follow in the selection of personnel
for a project of this type was to select personnel from
within the company with whom they were familiar and knew had
a stable and predictable personality. If this is not done,
experience reveals that there is difficulty with psychologi-
cal testing which is the least accurate of all tests.
It is recommended that the personnel selected for use in
the proposed phases of the development program should be
hand-picked for their stable and predictable personality,
their youth and knowledge of mining techniques and equip-
ment, their cautiousness, their curiosity about new and
different ideas, their ability to rationalize, their desire
to improve mining conditions and to be a part of a mining
program degressing considerably from conventional mining
techniques. Those selected should display qualities of
leadership as they could be future instructors and mine
foremen.
Medical Testing
A thorough medical examination must be an important part of
the personnel evaluation and selection program. The medical
record should include complete documentation of an
individual's medical history with remarks from the examining
physician. The medical examination should include:
Height Abdomen
Weight Arteries
Color of Hair Extremities
Eyes Internal Region
Ears Spine
Nose Skin
Mouth Genito-Urinary Disease
Neck Urinalysis
Heart Blood Pressure
Lungs Serology
Any defects that may disqualify an individual and his
specific work limitations.
The height, weight, respiration rate, blood pressure, hear-
ing ability, urine analysis and reflex actions should be
checked at regular intervals and as frequently as weekly in
the proposed demonstration program.
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Training
A training facility should be located outside the entry of
the sealed and blanketed mine and should contain a class-
room, a small gas lock chamber in which men can become
accustomed to the safety of their suits and apparatus, and
an enclosed garage in which individual pieces of mining
equipment may be operated by the men while wearing the
life support suits so that they can become accustomed to
such operation before having to perform it within the con-
fines of the mine proper. Approximately one month is
anticipated for training a ten man crew for a single section
in an air atmosphere before they would begin operations in
a mine under an inert blanket. During the conduct of the
proposed demonstration program, one day each week would be
utilized for retraining in safety procedures as well as in
developing revisions to operating techniques.
The training program for the crew to be used in an oxygen
free atmosphere mine utilizing life support systems must
be comprehensive in the use of the selected life support
system as well as in all of the mining techniques used in
conjunction with these systems.
The training program should consist basically of three
parts. Part one being strictly classroom discussions and
review of the various components. Part two should be the
testing and familiarization with the system components as
related to the operation of the mining equipment using the
training facilities at the mine mouth. Part three should
involve actual mining operations with all men in suits but
in a section of the mine maintained for this purpose in an
air ventilated status.
The classroom discussions must include an introduction to
and purpose of the project, miner's protective suit,
miner's mine personnel rebreather system, mine personnel
emergency rebreathing system, mine personnel communication
system, and safety.
In the case of the proposed demonstration mine, the intro-
duction should include as well a complete review of the
project including the benefits to be derived from it.
The mine personnel suit should be discussed and all personnel
made familiar with the construction of the suit, how it
operates, what maintenance procedures are required to keep
the suit in proper condition, what malfunctions of the suit
are likely, and how to test the suit for air tightness so
that mine atmosphere does not infiltrate the suit.
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All men must be expected to become completely familiar with
the construction and operation of the rebreather system/
and its maintenance. They must also become familiar with
those symptoms which might indicate a malfunction in the
rebreather system.
The miner must become completely familiar with the operation
of the emergency rebreathing system and its care and mainte-
nance .
The miners should also be instructed in the maintenance and
operation of the communication system and its capabilities
as well as the backup or emergency procedures provided.
The safety features of all components of the life support
system must be continuously reviewed as a continuing part
of an overall safety program. It is anticipated that all
likely situations would be examined in order to determine
what steps would have to be taken to assure the miner's
safety.
Part two of the training program should be the demonstration
and testing of the various components by the trainees using
the training gas lock for familiarization with operation in
an inert atmosphere. The miners should run selected pieces
of mining equipment in the training garage external to the
mine to become familiar with the installation of the
rebreather system on the mining equipment as well as the
problems involved with the tether system, vision, and hear-
ing. Confidence in the operation of the life support system
must be gained.
Part three of the training program follows the completion
of classroom and equipment familiarization. The mining crew
should be suited up and taken into the demonstration air
ventilated training section of the mine where they should
actually work a face under air ventilated conditions so that
they may further develop their confidence in the system and
refine their ability to work their equipment while wearing
the suits and supported by their rebreather. When part
three is completed, the men should be able to begin opera-
tion in an oxygen free atmosphere.
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SECTION XI
INSTRUMENTATION
Monitoring of the atmosphere in a mine and of the mine water
discharge is an essential part of the oxygen free atmosphere
process. This data is necessary to control the operation of
the mine, maintain safety procedures, determine the require-
ments for blanketing gas and the effectiveness of the process
on the quality of the water discharged from the mine.
Continuous monitoring of critical areas (gas locks) is
essential to provide instantaneous data for safe operation.
Routine programmed sampling should provide adequate data in
other areas. The discharged water quality should not
change rapidly enough to warrant the establishement of
continuous monitoring equipment except for possibly pH and
conductivity. Water samples collected at regular intervals
should be analyzed during the course of the mine operation.
The following monitoring and sampling system for Gas Quality
Measurement and Water Quality Measurements are typical of
those for full scale blanketed operations and are shown for
the proposed demonstration mine as an example.
Gas Quality Measurements
Monitoring of mine atmosphere quality is essential in order
to control contamination from either suit leakage, gas lock
leakage or from outside atmosphere. It is also essential
to provide detection of hazardous or explosive conditions
if they exist. Such monitoring requires a combination of
analytical instruments which must provide:
1. Intermittent measurements of gas composition at selected
points throughout the mine.
2. Continuous measurement of key componenets of the
atmosphere in critical areas where personnel safety is
of prime importance.
3. Intermittent measurements of the physical character-
istics of the mine atmosphere such as temperature,
pressure, and humidity.
By using a combination of sequential analyzers for general
data gathering of noncritical points and continuous
analyzers at points most significant to personnel safety
an effective instrument system is possible.
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The points that should be included in a sequential analysis
scheme are as follows (See Figure 12).
Point 1 mine atmosphere between working face and entrance
Point 2 refuge station personnel gas lock
Point 3 refuge station
Point 4 equipment gas lock
Point 5 personnel gas lock
Point 6 coal gas lock hopper
Point 7 working face
Point 8 inert gas generator effluent
Point 9 outside ambient atmosphere (physical properties
only)
The points that require continuous gas quality monitoring
include the refuge station (point 3) and its personnel gas
lock (point 2) and the personnel gas lock arrangement
(point 5) and the equipment gas lock (point 4). In addition
physical properties including humidity, pressure and temper-
ature should be continuously monitored at the inlet and
outlet sides of the air conditioning unit as well as at
point 9. Temperature and humidity measurements at other
points in the mine would best be achieved by using portable
instruments.
The points for sequential analysis for gas composition
include points 1 through 8. There is no need to monitor
the gas quality of the outside atmosphere (point 9).
In the proposed demonstration mine example the continuous
and sequential gas quality analysis instruments should be
located in the control room and should receive gas samples
from points 1 through 8 by means of a continuous sampling
system as shown in Figure 13. Gas should be pumped with
individual vacuum pumps from each point through a series
of filters and condensate traps to the control room as
shown in Figure 14. Each sample line should be split into
two streams/ one for the sequential analyzer and the other
for the continuous analyzers. Monitors for combustibles
should be located at the points of sampling in the two
gas locks.
The instruments for measurement of physical properties
should be located in the control room since they can receive
electrical signals from sensing elements located at the
points of measurement. In the case of full scale well
developed mines, certain of the refuge stations could be
used for location of the measuring instruments was to reduce
the length of the sampling lines. Results would then be
telemetered to the control room.
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Points
Mine Atmosphere
Between Working
Face & Entrance
Refuge Station
Personnel Gas Lock
Refuge Station
Equipment Gas Lock
Personnel Gas Lock
Coal Gas Lock Hopper
Working Face
Inert Gas Generator
Effluent
Outside Atmosphere
Inlet to Air conditioner
Outlet From Air ($]
Conditioner
FIGURE 12
Sampling Points
-------
o
o
VENTED STREAMS FROM
3-WAY SOLENOID VALVES
POINT
POINT 2
POINT 3
POINT 4
POINT 5
POINT 6
POINT 7
POINT 8
PI
!P2
P3
IP4
5
•PS
'P7
8
llllll!
AUTOMATIC
STREAM
SELECTOR
HX 1
VI
V2
PROCESS GC UNIT
INCLUDING RECORDER
VENT
JADI
-VALVE FROM WAY STATION
NORMALLY OPEN
3 PEN
RECORDER
OXYGEN
ANALYZER
VENT
AD3
(BUILT-IN
RECORDER)
-{X—'
V8
FIGURE 13
PI-P8=VACUUM PUMPS
VI-V8 "MANUAL VALVES
ADI-AD3 = ANTI DIFFUSION COILS
SAMPLING SCHEME
-------
r
1
VENT
(F)
(C)
AUTOMATIC
STREAM
SELECTOR
SAMPLE
INLET
(DRAIN)
TYPICAL (8) PLACES
(F) AUTOMOTIVE AIR FILTER (PAPER CARTRIDGE TYPE)
(C) FILTER WITH CONDENSATE TRAP
(P) VACUUM PUMP
PROCESS GC UNIT
INCLUDING RECORDER
VENT
i
VENT
OXYGEN
ANALYZER
FIGURE 14
GAS SAMPLE LINES
-------
The principal sources of information for the gas quality
instrumentation were the Beckman Instrument Company and the
Mine Safety Appliance Company. The instruments suggested
are based on their experience in the area of process
instrumentation.
Continuous Analysis Instruments
The refuge station (point 3) gas quality should be monitored
on a continuous basis. The gases analyzed should include 1)
carbon monoxide, 2) methane, 3) carbon dioxide, and 4)
oxygen. The first three gases can be handled by three non-
dispersive infrared analyzers connected in series. The
fourth, oxygen can be analyzed by either a polarographic or
a paramagnetic type analyzer connected in parallel to the
infrared units. The results should be recorded by a
multipoint unit.
The sample stream for this continuous analysis system should
be taken from a manifold that is common to sample points 1
through 8. Each stream should pass through shut off valves
prior to Centering the manifold. With this arrangement one
of the eight sample streams can be continuously monitored at
a time. During normal operations the valve connected to
the refuge station sample line should be open and the others
closed. If the need should arise any one of the other
sample streams may be continuously analyzed by merely shut-
ting off the refuge station valve and opening one of the
other required valves.
Continuous combustibles analyzers should be located at the
refuge station personnel lock (point 2) and the equipment
personnel lock (point 5). These instruments serve to warn
of the presence of a combustible gas mixture resulting from
mixing of air and mine atmosphere and thus indicate the
need for additional purging of the gas locks. These instru-
ments include three lights: one indicates power on, a second
indicates conditions are safe and the third indicates unsafe
conditions. A warning alarm should be used in conjunction
with the third warning light.
A standard weather instrument package including an
anemometer, aerovane, dry and wet bulb thermometers, and
a rain gauge should be used with transmission to appropriate
recorders in the control room.
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Sequential Analytical Systems
The sequential analysis instrumentation system should
include a process gas chromatograph, an automatic stream
selector unit, and vacuum pumps, PVC sample lines, filters
and condensate traps (Note: taps are taken at the outlet
of each pump for the manifold connected to the continuous
analyzers). This process gas chromatograph instrument must
be able to analyze for 1) carbon monoxide, 2) methane,
3) carbon dioxide, 4) nitrogen, and 5) oxygen. Each measure-
ment cycle for the five components requires approximately
6 minutes to complete. All 8 sample streams, therefore,
should be able to be analyzed within approximately 50
minutes.
For safety purposes, the automatic stream selector should
be able to be switched to manual operation should the need
occur to look at a particular gas stream out of the pro-
grammed sequence.
Measurement of Pressure, Temperature and Humidity
Humidity and temperature sensors should be installed on the
inlet and outlet of the air conditioner. The data thus
obtained enables the efficiency of the air conditioner to
be monitored and provides information on the temperature
and humidity change within the mine.
Pressure changes within the mine should be monitored with
a differential pressure instrument relative to the outside
atmosphere. Outside atmospheric pressure measurements
should be made with an absolute pressure recorder and dis-
played together with the differential on a two pen recorder.
Differential pressure measurements should also be made across
the ventilation fan.
The most practical approach to temperature and humidity
measurements within the mine, is to perform them manually.
This eliminates a multiplicity of sensors and connecting
wires which might pose a problem. Temperatures and humid-
ities should be recorded periodically by mine personnel
using a sling psychrometer.
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ESTIMATED INSTRUMENTATION PURCHASE COSTS
BASED UPON PROPOSED DEMONSTRATION MINE
Continuous Analysis Instruments
1. Nondispersive infrared analyzers
a. Carbon monoxide
b. Carbon dioxide
c. Methane
2. Oxygen analyzer (with recorder)
3. Combustibles analyzers (3)
4. Three-pen recorder
5. Miscellaneous hardware
Total
$ 2700
2600
2800
3300
2600
1000
1500
$16500
Sequential Analyzer
1. Process gas chromatograph including:
programmer, analyzer, automatic stream
selector, pumps, tubing, filters,
valves, etc.
$12000
Pressure Temperature Humidity Instruments
1. Absolute Pressure Recorder
2. Temperature
a. Dial thermometers (5)
b. Thermo couple s (2)
c. Recorder (1)
3. Humidity
a. Fixed sensors (2)
b. Portable unit (1)
4. Weather Station
$ 500
Total
$ 6000
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Water Quality Monitoring
Continuous monitoring and sampling should be conducted for
a few key parameters of drainage from a sealed mine and in
the case of the proposed demonstration project, from the
adjacent air ventilated mine. The degree of surveillance
after a preliminary period should be dictated by the analyt-
ical results. The results will probably be influenced by
the effectiveness of the mine sealing techniques and the
ability to maintain a constant low oxygen concentration in
the mine atmosphere. Composite sampling for periodic
analysis for other parameters should supplement the con-
tinuous measurements.
Information on samplers and monitoring equipment is abund-
ant but data on use of the equipment is sketchy and limited.
It appears that most of the suppliers are of the small job
shop type and service maintenance of the equipment is
questionable.
The investigation into continuous multiparameter monitoring
systems covered three makes: 1) Schneider, 2) Geodyne and
3) Automated Environmental Systems. The specifications for
the three appear to be very similar. ORSANCO uses the
Schneider instrument.
Composite samplers evaluated included the following:
1) Serco, 2) Pro-Tech and 3) N-Con
The Serco sampler is made of lightweight aluminum and is
compact. It requires no electrical or plumbing hook up
for its use in field operation. The unit is evacuated by
means of a vacuum pump. Upon evacuation of the sample
bottlesr valves are closed and the unit is then ready for
sampling. The samples are taken by suction. A hand-wound
timer can be set to open valves to individual .evacuated
bottles at intervals of 1 hour, 30, 15, 10, or 5 minutes.
The sampler case is insulated. To further control temper-
ature of the samples, the sampler can be heated with canned
heat in cold weather or cooled with ice in the collection
of certain samples.
The Pro-Tech sampler uses electrical energy to obtain com-
posite samples automatically. The sample is delivered to
the sampler from a submersible magnetic-drive pump which is
placed in the liquid to be sampled. The unit operates on a
continuous flow principle, returning the uncollected sample
to waste. Sample volume is determined by the setting of a
solid-state timing control, together with the sampler
105
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repetition rate, and the duration of the flow signal re-
ceived from the flow recording device. The weather-proof
sampler case is made of aluminum with durable baked-vinyl
finish. All tubing, valves, fittings and hardware are of
PVC, nylon, brass, and stainless steel construction.
The N-Con is a battery operated sequential composite type
sampler. The instrument is capable of collecting twenty-
four 500 ml composite samples over a period of 8, 12, or 24
hours. The sampler is easily portable by one man and pro-
vides the convenience of a single inlet tube. The operator
sets the desired number of hourly aliquot samples and
adjusts the volume control for aliquot sample volume. When
all 24 bottles have been filled, the sampler automatically
shuts itself off.
Each unit has its good and poor features but from an overall
standpoint the Serco sampler should be used for the follow-
ing reasons:
1. It is compact and lightweight.
2. It does not require electrical hook up for
field operation.
3. It is insulated.
4. Temperature can be controlled with ice
or canned heat.
In reviewing the sampling and analytical requirements for the
proposed demonstration mine, it was determined that the
characteristics of the local stream would probably not vary
rapidly enough to warrant the expense of continuous analysis.
It is expected in general that a sealed mine discharge
does not appear to warrant continuous analysis for the full
range of parameters of interest. Periodic samples for lab-
oratory analysis for parameters other than pH and conduct-
ivity should be taken of the mine water discharge.
In the case of the demonstration mine these samples should
initially be taken weekly in order to establish base line
data and later on monthly to develop a complete seasonal
record. Continuous analysis for pH and conductivity of the
mine discharge should be made and the results recorded in
the control room. Continuous surveillance of pH and con-
ductivity should detect any periods of rapidly changing
water characteristics that may result from mine atmosphere
quality changes.
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Continuous pH and conductivity recorders are available com-
mercially from many sources. Separate locally mounted sens-
ing elements with standard recorder output should be used
at the mine water discharge pond to transmit the output to
a multipoint recorder located in the control room. In the
case of the proposed demonstration mine a similar instal-
lation should be made at the adjacent active mine with the
recorder located in the mine office or other convenient
building.
To conduct the composite sampling program on the Serco
samplers one for each discharge with extra sample bottles,
a spare vacuum pump and additional component parts such as
sampling heads, rubber sampling lines, spring driven clocks,
etc. should be provided. Dependent on varying operating
conditions individual samples should be analyzed for the
following parameters.
pH Total acidity
Conductivity Dissolved solids
Total iron Manganese
Dissolved iron Chlorides
Total alkalinity Sulfates
The proposed Serco samplers and spare parts are estimated to
cost approximately $1200 each. The instruments are avail-
able with deliveries of 30 - 60 days. The samples collected
by these samples should be preserved as recommended by the
analytical laboratory and sent to the laboratory for
analysis.
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SECTION XII
DATA COLLECTION
An operational data acquisition system plays an essential
role in the conduct of major projects. Such a system should
accumulate all pertinent data on personnel, equipment and
facilities utilized in the preparation and operation of the
oxygen free atmosphere mine. Data recorded should include
capital, operating and maintenance costs associated with
the equipment and facilities; physical and psychological
records on all personnel; production logs; and detailed
maintenance records. Such data is necessary for a thorough
evaluation of inert gas mining operations so that system
modifications may be developed, and comparative analysis
of inert gas mining operations may be made with those of a
standard mine.
The data acquisition system should be designed to collect
and present data in several formats consistent with the
type of data being collected. Data records should include
standard report forms (i.e. production, safety, medical,
supervisory, injury, etc.), cost accounting records, equip-
ment service records, strip chart records and time reports.
Where possible, existing report forms should be utilized
to acquire the same base line data commonly maintained on
standard mining operations. All record formats should be
so designed that they can readily be utilized for computer
input for more sophisticated data analysis. The frequency
of recording data and the type of record maintained depend
on its relative importance to analysis of inert gas mining
operations.
Data of a general nature kept on each item of system equip-
ment and facilities should include a description of the item;
model, item or identification number; list of associated
spare parts; and the capital cost of the item and any spare
parts.
Installation cost data for erecting equipment in the mine
and outside the mine should be recorded on a daily basis
showing labor, supplies and utility services required for
all items installed. Service and maintenance costs should
likewise be maintained on a daily basis on all items from
the time of installation.
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All of the aforementioned cost data will be required, as
applicable, for each of the following systems or items, as
well as operating data unique to the system or item itself.
Inert Gas Generation System
Capital cost data on equipment for this system should cover
the blower, burner, gas holder, cooling units, filters,
ductwork, piping, accessories and recommended spare parts.
Service and maintenance costs should be readily discernible
in terms of the period of initial charging as opposed to
the time of standard operation of the mine. The purpose for
such separation of costs is to subsequently provide a more
reasonable basis of cost comparison with other system
operating costs. An hourly record of such costs should
be maintained as well as associated data including the date
and time an item was taken from service, date and time the
item was returned to service, down time per shift, reason
for repairs, and a description of the repairs performed.
The initial charging record of the mine should include the
date and time that inert gas blanketing began and the date
and time that it was determined that the inert gas blanket
was suitably established. Under normal charging conditions,
general system data collected during the course of the mine
operation will include a daily record of date, starting
and quitting time for each shift and non-shift period,
shifts per day, and the volume of the mine atmosphere. Mine
and ambient temperature and pressure should be logged hourly.
The mine breathing rate (inert gas makeup to mine or in the
case of a methane atmosphere, the gas bleed off rate) should
be recorded continuously as should the flow to personnel,
equipment and material gas locks.
Normal operating data for the gas generators during initial
charging and regular operation should include the production
rate in SCFH, SCFH of natural gas fired, gpm and delta T
of the cooling water used, wet and dry bulb temperature of
the product gas, composition of the inert gas discharged,
and the blower power consumption.
The gas holder serves as a collection facility for the inert
gas generated. It maintains a sufficient reserve to supply
the inert gas system requirements of the mine under the most
demanding conditions of gas lock operation, mine breathing,
and maintenance of the mine atmosphere. During initial mine
charging and standard operation, data which should be
110
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recorded to monitor gas holder operation should include the
pressure and temperature of the gas in the holder, and the
holder volume in SCF (continuous record). The gas holder
should maintain a reserve supply of inert gas during normal
operation of the demonstration mine and all measurements
should be continuously monitored and logged regularly at the
mine's control center.
Gas Quality System Data
The quality of the atmosphere in each major component of the
mine system should be determined continuously as previously
discussed. Log sheets should be maintained, with two
entries per shift, for each item continuously recorded or
indicated on system instrumentation. A log sheet record
should be maintained which indicates each dangerous CH4
reading with respect to the time of initial occurrence and
the length of time that the condition existed.
Water Quality Data
In the case of the proposed demonstration mine, a compre-
hensive sampling and monitoring program for water surveil-
lance at both mine sites should be conducted over the period
just preceding and throughout the demonstration mine project,
A major reason for collecting such water quality data is to
provide good comparative data on the effects of the two
different mining techniques and the quality of mine drainage.
The mine discharge at each mine location should be monitored
on a continuous basis for their pH, conductivity and flow
rate. Maintenance of a log of these measurements once per
shift should provide sufficient indication of operating
conditions and/or the need for system modifications.
In any new sealed mine operation weekly grab samples should
be taken initially of mine drainage. After the initial sampl-
ing period, changes in weather, stream flow and operating
practice may warrant modified sampling schedules.
Characterization of the water quality from each grab sample
should be determined by standard analytical procedures for
pH, conductivity, dissolved solids, total iron, total
alkalinity or acidity, manganese, chlorides, sulfates and
suspended solids.
Ill
-------
The effectiveness of the mine seal in eliminating oxygen in
the mine atmosphere and in turn eliminating mine acid dis-
charge should be determined by the results of the sampling
and analysis program.
Life Support System
The entire life support system (suits, helmets, emergency
breathing equipment, rebreather, and communications) should
be evaluated to determine the adequacy and effectiveness of
all components with respect to operations in the sealed
mine.
Log sheets should be maintained on each man's reactions
and problems with system equipment as well as a service
record for system equipment itself. Data on capital costs,
operating costs, maintenance costs, and reports on repairs,
failures, cleaning and inspection should be maintained on
log sheets as routine practice.
Data maintained on the three parts of the miner's life sup-
port suit (undergarment, middle garment and outer garment)
should include the number of garments required per man,
unit cost of each garment, period of usefulness, date
placed in service, date of replacement, and the comfort,
fit and freedom of movement attainable under the weight
and restrictions of the suit. When replacement of a
garment is required, a separate data record should be main-
tained and include the reason for replacement, date of each
occurrence, cost of replacement, and the parts required for
repairs.
Additional information documented on the middle garment
should include the results of routine pressure/leakage tests,
suitability of quick disconnect connectors and connections
in terms of leakage and proper fit, effective utility of
boots and gloves, and an evaluation of abrasive wear.
The record maintained on the miner's helmet should include
general data and replacement records similar to those kept
on the miner's suit. Information peculiar to the helmet
which should be kept in addition to the aforementioned
includes an evaluation of dust and fogging problems associ-
ated with the visor, effectiveness of the earphone and
voi-cemitter communication equipment and line of sight vision
problems.
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The emergency breathing system equipment is necessary for
sustaining operating personnel within the mine atmosphere
upon failure of the main rebreather system. The record
maintained should include an identification or serial number
of each potassium superoxide canister, source and date of
manufacture, date canister is placed in service, serial
number of emergency rebreather in which placed, and date
of replacement.
The mine personnel rebreathing system is considered to be
the most important part of the life support system to each
miner as he works in the inert gas atmosphere. A log record
should be kept on the unit as a whole as well as on each
major component of the system.
Data on the carbon dioxide absorber used to purify the air
system should include the serial number, source and date of
manufacture, date installed and removed, serial number of
rebreather in which it was installed, and any problems of
operation.
Common data recorded on the air conditioning portion of the
mine personnel rebreather filters, recirculation blower,
and the tether hose should include unit costs, frequency
of replacement, parts required, replacement costs, and
problems associated with use. In addition, the results
of regular capacity tests should be maintained on the air
conditioning portion; the results of regular tests for
pressure drop should be kept on the recirculation blower;
the results of pressure/leakage rate tests and the extent
of abrasive wear should be maintained on the tether hose.
Miners should be interviewed or given questionnaires period-
ically to ascertain their reactions to life support equip-
ment operation. Data of a general nature should be obtained
for the system such as adequacy of power source, replacement
or recharging of power source, malfunctions, effectiveness
of any warning alarm system, maintenance per unit, remedial
action required in system design, and the number of units
required per man.
The communications operation within the mine should also be
monitored. A primary consideration should be the capital
cost of the system components which includes battery powered
transceivers, earphones, microphones, coaxial cable, remote
transmitting station equipment, closed circuit TV system,
and the antenna system. Maintenance data, as earlier
defined, should be acquired; they should include a record
of routine inspections, battery replacement frequency,
recharging requirements, labor utilized, and associated
113
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service costs. Other general data should include the qual-
ity of TV reception, dust problems on the TV camera lens,
and voice transmission reception from miner to miner, miner
to control room, refuge station to control room, and miner
to refuge station.
System^lining Equipment and Facilities
A record should be maintained on all major operating equip-
ment used in the mining of the coal, as well as on the
control room equipment utilized for system surveillance.
The operating cost record maintained on the aforementioned
equipment should include data on battery recharging and on
the replacement of consumables such as cutting heads and
drill bits, roof bolts, explosives, tires, etc.
Mine Operation
A detailed record of coal production should be maintained
for each shift and each day that the mine is in operation.
The log sheet for this purpose should include the number of
cuts of coal per miner; cuts of coal per day; tons of coal
removed per day (actual against projected); number of shifts
worked per day; cost of associated labor, supplies, overhead,
services, and delays incurred (mechanical, condition, co-
ordination minutes, percent of delay time, percent of
face time) .
Data accumulated on the miners and their performance should
include a shift and daily record of time spent in the mine
by the miners, time spent at the face, travel time in,
travel time out, tons loaded, actual tons per man, expected
tons per man, performance ratio, number of mine cars loaded
number of cuts made, tons obtained per cut, standard and
actual crew size, standard and actual tons mined per shift,
standard and actual tons mined per man, and standard and
actual total tons mined.
A separate record should be maintained for any additional
general supplies required to produce coal.
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Weather Station
Meterology data should be collected at the mine site. Such
data should include wind direction, velocity, barometric
pressure, temperature, humidity and amount of rainfall.
In-Mine Facilities
Records of capital costs and maintenance costs should be
maintained for all major in-mine facilities. Capital cost
data should be compiled at the time of purchase for the high
voltage cable, mine lighting equipment, dust collection
system equipment, refuge station facilities, personnel
locks, equipment locks, product removal equipment, and
ventilation system equipment.
The data log on the personnel locks in the mine should
include a record of the number of times passage is made,
the number of personnel per passage, time required to
complete passage through the lock, amount of leakage at
the lock, inert gas demand when transfer occurs, volume
of gas exhausted to atmosphere, and volume of gas required
to maintain the lock atmosphere. A similar record should
be maintained on the equipment locks and refuge stations.
Personnel
Complete medical records should be maintained on all mine
personnel before and during their service in the oxygen
free mine. These medical records should contain basic
data on the physical condition of each miner as well as/or
the psychological effects on the miner that may be due to
working in the specialized atmosphere and conditions of
the sealed mine.
Personnel records on a worker's physical condition should
include the person's name, address and telephone number;
and a record of physical defects, previous mine injuries
which include information on type, duration and persistent
problems. Basic information, which should be checked
initially on a weekly basis and later on a monthly basis
should include height, weight, respiration rate, blood
pressure, hearing ability, urine analysis and reflex actions.
This basic information should be reviewed as collected, to
determine significant trends and changes which might warrant
further tests or alteration of mine operating procedures.
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The questionnaire portion of the physical record form should
inquire whether the miner has or has had shortness of breath,
asthma, tuberculosis, chronic bronchitis, lung disorders,
or coughed up blood; and if so, when and for how long has
such a condition existed. The record should also contain
an up-to-date listing of when and where the person's lungs
were last X-rayed; and X-rays should be scheduled at
yearly intervals to keep a thorough record. Indication
should also be given if the miner has ever had silicosis
or other lung disease; and if so, a detailed description
of each occurrence should be made. Complete information
on all injuries requiring surgery should be maintained and
should include a description of the injury, surgery per-
formed, time and duration of occurrence and any after ef-
fects .
Safety
The mine must be under constant scrutiny to maintain the
safest operating conditions possible for personnel working
in the oxygen free atmosphere. A dust count should be taken
at the mine face and at the ventilating fan at the begin-
ning and end of each shift to develop and maintain a rela-
tionship with visibility. The mine must have scheduled
monthly inspections from which a comprehensive report must
be made, giving special attention to gas lock operation,
gas circulation adequacy, and conditions which would con-
ceivably produce fires or explosions.
All data collected should be recorded on log sheets or be
transferred to same from automatic monitoring equipment
readouts or indicators. In this form, all data should be
in a format acceptable for transferral to computer input
media, if desired. Where possible, existing data acquisi-
tion forms should be used. Some existing forms should be
modified to include inert gas atmosphere operational data
and some new forms should be designed for the collection
of information peculiar to the oxygen free operation.
Maintenance of Standard Report Forms
Standard report forms should be maintained by all classifi-
cations of mine personnel on the operations of the oxygen
free mine.
116
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Records routinely kept on air ventilated mines and which
should be maintained for both methods of mining include the
following representative forms and records:
Miner's rating sheet - a report sheet on basic mine
operations conducted per day.
Daily and weekly time sheets - used to record setup time,
maintenance time, and production hours worked.
Maintenance request form
Unit repair report
Repair job record
Job order form
Trailing cable - shop work report
Trailing cable work report summary
Stationary air compressor daily inspection form
Coal skip hoist inspection form
Mine fan daily inspection
Overhauled equipment performance report
Maintenance shift report summary
Equipment maintenance work sheet
Monthly report of equipment overhauled
Equipment location and repair case history record
Summary of work accomplished
Electric motor or armature repair, case history record
Daily report of units or major parts changed on equipment
Equipment overhaul - monthly report of jobs completed
Daily record of breakdown or delay repairs and shop
work assignments
Summary report of operating shifts, maintenance labor,
and equipment delays
Record of equipment overhaul dates and place of overhaul
Personal data record
Daily safety inspection report
Factors for safety program appraisal
Record of air measurements
Some existing forms need to be revised to incorporate data
unique to the inert gas mining operations and new forms
need to be developed solely because of the new method of
mining. Examples of such data records are as follows:
Miner's acknowledgement sheet on safety procedures instruc-
tion - a form exists for standard mining practices but a
new one should be developed to incorporate new requirements
imposed by inert gas atmosphere mining operations (i.e.
instruction in use of the suit, breathing apparatus, lock
procedures, etc.)
117
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Check sheet for safety program appraisal.
Check sheet for breathing system operation - new form
required.
Foreman's injury report - a standard form already in use
should be modified to include the cause of injury; injury
caused by equipment, breathing system, or suit failure and
the nature of the failure; psychologically caused injury
date, time, and location of site at which injury occurred.
Medical report forms - reporting all physical examinations
performed.
Medical report summary form - for weekly or monthly compar-
ison of the major physical data on each person (i.e.,
respiration rate, blood pressure, weight, etc.).
Supervisor's rating sheet - a new form should be developed
to evaluate the inert mine operations (i.e. actual inert
gas mine productivity versus anticipated, and as compared
to standard operations).
118
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SECTION XIII
SAFETY
Of paramount importance at any mine site is the safety of
the personnel who work there; consequently, the effective
planning and implementation of safety procedures in the
mine as well as for operation of the external systems and
facilities are a principle concern. Island Creek Coal
Company, Department of Safety, for example has a proven
program to keep in step with modern mining practices and
the regulations of the state mining authorities. The
personnel at the proposed demonstration mine site must be
expected to make safety the first consideration.
General Safety Rules
1. No persons other than specified personnel on duty or
other authorized persons may be permitted to enter the
proposed demonstration mine or buildings or adjacent
premises unless properly authorized by the Project Director.
2. Good housekeeping must be practiced in and around the
mine.
3. All personnel upon entering the mine must go direct
to their working position and no person may loiter in or
about the mine.
4. Personnel must not tamper with any door, regulator or
stopping used for atmosphere control or with any machinery
or equipment in or about the mine except in the discharge
of his duty.
5. Personnel must not ride on timber or other supply
trucks. No one may ride on top of tractor or in shuttle
cars.
Handling of Explosives and Blasting
1. No hole may be charged or fired in any place where an
explosive gas mixture can be detected.
2. Only clay or other non-combustible or approved material
may be used for stemming, and the drill holes must be
stemmed according to law.
119
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3. Proper warning must be given by the shotfirer when shots
are to be fired, by calling out "FIRE" three times about ten
(10) seconds apart. All entrances to places being blasted
and to the adjacent place when a breakthrough is being
blasted must be vacated and no one may be permitted to enter
until blasting operation is completed. The shotfirer must
see that these safety precautions are taken.
Machinemen and Drillers
1. Machinemen and drillmen upon entering a working place
must bring their machine to a complete stop outby the last
open breakthrough and it must not be moved again until a
thorough examination has been made of the area inby that
point for loose coal and bad roof. Additional examinations
at frequent intervals (at least every 20 minutes) must be
made while the machine and drills are operating in the face
area.
2. The reverse lever on the controller must be set at
neutral and the brakes tightly set when mining machines and
drills are not tramming and when parked at working faces.
3. Miner or loader operators, machinemen and drillmen must
use every precaution when tramming to prevent injuries to
themselves and collision with other equipment.
4. The bit clutch must be disengaged and the cutter chain
or cutter ring locked with a safety bit guard or other
suitable device designed for this purpose, when the machine
is being trammed or is parked.
5. The front bits must be removed from the cutter bar of
the cutting machines or it must be guarded while tramming.
Miner and Loading Machine Operators
1. Extreme care must be used in moving machines from place
to place. The operator must keep his conveyor boom in such
position as to prevent knocking out timbers or contacting
power or communications lines. Machines must not be
trammed from place to place with gathering head of conveyors
in motion and safety chains must be used on the gathering
arms of loading machines and cutter rings of miners.
Reflectors or lights must be installed on the rear of such
machines.
2. Unauthorized personnel must not be permitted at the
working face while machines are in operation.
120
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3. No person may stand along the side of the boom while it
is in operation.
4. Miner helpers or other persons must not work or stand
at the face in front of or near the gathering head when
loading or other mobile machines are operating unless in
full view of operator.
5. The operators must not leave the controls while the
miner or the loading machine is in operation or in motion,
and they must give every consideration to the safety of
other persons when loading and unloading cable.
6. The operator or other designated person must test the
roof between car changes and when working ahead of
permanent roof supports (where temporary supports are used)
using a testing bar or other approved device provided for
that purpose.
Timbermen - Roofbolters
1. It must be the duty of each roofbolter, timberman and
helper to make a careful examination of the roof and
surrounding conditions before beginning work in any place,
and do that which is necessary to make the place safe.
Safety posts or jacks must be used during bolting opera-
tions .
2. Safety posts or jacks must be used where bolts are used
for roof support during cutting, drilling, blasting and
loading operations if the employees have to go beyond the
last permanent timber or roof support.
3. A danger sign must be put up if a place is left in an
unsafe condition and the place is not completely bolted or
timbered by the end of the shift.
Outside Facilities
1. All outside personnel must observe all precautions to
insure safety to himself and all other persons.
2. All outside men must see that their working tools are
kept in a safe condition.
Since a mine planned for oxygen free operation should be
constructed initially using normal air ventilating
techniques, all current safety and fire regulations
including the foregoing would have to apply to the mine
121
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during that period. Nonflammable hydraulic fluids, fire
resistant belts, and fire sensors should be used on the
belt conveyor and all other requirements of the Federal
Coal Mine Health and Safety Act of 1969 should be applied
to the mine at least for the period of initial air opera-
tion. Chemical fire extinguishers should be available at
the working face, on each piece of mining equipment, on
permanent electrical installations, temporary electrical
installations, and at the refuge station. In addition, a
water line should be run parallel to the belt conveyor to
the loading point and fire hoses should be provided
according to the Health and Safety Act. In addition, a
water reservoir of approximately 3,000 gallons should be
maintained as a water supply source for the water system
for emergency use.
During the period of purging a mine with an oxygen free
atmosphere, there should be no personnel within the mine
proper. No person should be sent into the mine until the
gas quality monitors within the mine indicated that the
mine had been purged and that the oxygen concentration was
below that able to support combustion.
The proposed mine design recommends the circulation of the
gas within the mine for cooling and dust control. The
mine ventilating fan should be used to recirculate this
air and the necessary stoppings erected to direct the
inlet air flow to the working face. This design should
provide the necessary air currents for cooling and dust
removal at the working face. The ventilation passage also
could provide an emergency escape route that could be
rapidly purged with outside air should there be an emergency
that would require such action. All outside dampers and
explosion doors should be constructed in such a manner as
to be able to provide fresh air to the mine in a minimum
amount of time. Should an emergency develop requiring such
action, all power to mine should be shut off externally
except that required to operate the ventilating fan.
Before entering a mine in an oxygen free atmosphere all
life support equipment must be checked out by the miner
following a prescribed check list. He must check to make
sure that a new C02 canister has been installed and that
his oxygen bottle is full. Once he has dressed in his
suit he must check the suit for pressure tightness. Follow-
ing this he must test the oxygen module of the rebreather
to see that it is functioning properly and that he is
getting an adequate breathing supply. During this latter
checkout, the oxygen module should be connected to a fixed
122
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chiller module provided in the checkout room. Gas quality
monitors must be used to check on the performance of the
complete system after a 5 minute or so test operating
period.
In the mine entrance gas locks and in the refuge station
the doors of the gas locks must be mechanically interlocked
so that both doors cannot be opened at the same time. Also,
a combustible gas indicator should be located in the gas
locks that would indicate whether it was safe to proceed
from the gas lock into the refuge station. The inside of
the gas lock must be coated with a non-sparking coating.
If the gas locks are performing properly, there should be
no possibility of a combustible oxygen-methane mixture
occurring. As a precaution, however, these non-sparking
features must be incorporated.
Oxygen can enter the sealed mine in the battery compartments,
wiring conduit and motors of that equipment routinely enter-
ing and leaving the mine. All conduit on this equipment must
be purged with nitrogen and sealed to maintain a nitrogen
atmosphere in the conduit or purged with nitrogen each time
it transits the locks. All motors likewise must be gas
tight and be purged with nitrogen prior to completing the
gas seal or purged each time as above. Every effort must
be made to prevent oxygen from entering the mine, or in the
case of a methane mine, of methane from leaving the mine in
the void spaces in electrical equipment.
A 3,000 gallon storage tank or water reservoir must be
maintained as a supply for the water distribution and fire
prevention system. A gasoline driven water pump should be
incorporated so as to provide for fire protection in the
event of power failure.
With the exception of the refuge station and the resuscita-
tors all of the safety items to be incorporated for the
sealed mine should follow standard practice for an air
ventilated mine in compliance with the Federal Health and
Safety Act of 1969.
The emergency treatment and removal of injured personnel
from an inert gas blanketed mine requires somewhat
different procedures than currently being used in air
ventilated mines. The major concern is that of keeping the
injured man supplied with oxygen during emergency conditions.
In the case of a full scale mine operating under these
conditions, the injured personnel would be taken to the
refuge station for emergency treatment should immediate
transportation by personnel carriers not be available.
123
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In the proposed demonstration mine since it would be of
limited size, it would probably be more expeditious to
remove the injured from the mine directly.
In all cases of serious injury within a sealed mine, it can
be assumed that the life support system would have been
ruptured. -The first action therefore should be to see that
the injured man has a supply of oxygen; the next action
should be to control any bleeding that may be taking place.
If the injured man is conscious, he should be able to use
his emergency breathing system until assistance can arrive.
Mine personnel upon observing the extent of injury should
make the decision as whether the injured man can be safely
moved to either the refuge or out of the mine while
continuing to use the emergency breathing apparatus. If
there is danger in removal while on the emergency systems,
the resuscitator should be secured from the nearest source.
The helmet should be removed from the injured miner, and
the resuscitator applied. The latter will supply breathing
oxygen.for the man without requiring any extra effort from
him. First aid treatment should then be given and the
injured man removed from the mine.
Since shock is one of the major problems in case of acci-
dent, it is essential to keep an injured victim warm; it
is also important under the conditions in a sealed mine that
the injured man be placed on a resuscitator as quickly as
possible. The gas tight garment and underwear will permit
the retention of body heat and assist in keeping the man
warm prior to his removal from the mine.
In the case of an injury where the man is trapped for an
extended period of time, it is essential that the rescue or
aid party sees that an adequate supply of oxygen is
available for the injured party. It is necessary, there-
fore, for all miners to know the time limits of all re-
suscitators and other equipment used for this emergency work
and that emergency oxygen bottles for replacement be avail-
able in the refuge station.
In case the injured is unconscious, the helmet should remain
on until the resuscitator has been secured and brought to
the location. There are several minutes of breathing
atmosphere in the helmet and suit. As soon as the resusci-
tator is brought to the scene and readied for application,
the helmet should be removed from the injured party and the
resuscitator applied. The resuscitator should be of such a
type that it will supply a positive oxygen pressure to the
124
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individual in a rhythmic fashion so as to simulate the
normal breathing cycle, the resuscitator should supply only
the oxygen required and act as a demand breathing system.
It is not anticipated that specialized equipment beyond that
currently being used for mine rescue and safety work covered
be required for the oxygen free mine, with the possible
exception of the resuscitator. The major difference would
be the location of this emergency equipment. All emergency
equipment must be readily available in the vicinity of the
refuge station in the mine. Without having to enter the
refuge station, additional units should be located in the
electrical substation, and in the boss cars. Spare oxygen
bottles for the resuscitators and as well as spare
emergency equipment should be kept in the refuge station.
The resuscitator recommended is the MSA-Special Portable
Resuscitator. It weighs 45 pounds and contains 40 cubic
feet of oxygen which should last for 1-1/2 hours. In an
emergency, 2 men could be supplied with oxygen. This unit
supplies forced ventilation when breathing has stopped,
however, when normal breathing resumes, it supplies oxygen
on demand.
125
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SECTION XIV
PROJECTED MINING COSTS
On the basis that the projected production costs for the
suits and life support units are approximately correct as
previously discussed and further that the productivity of
the miner will not change substantially, estimates can be
made of the added capital cost of placing a deep coal
mine in an oxygen free atmosphere and of the added cost
of operation under such conditions.
A 5,000 ton per day deep coal mine with conventional
equipment is a reasonable size to use as an example.
Five operating sections with a total two shift per day
work force of 180 men appears typical for such a mine.
In calculating nitrogen gas requirements in the case of a
nitrogen blanketed mine, a 1,000 acre mined area (pillars
remaining) is a satisfactory basis. A gas production of
15 x ID** cubic feet per day is reasonable if it is a gassy
deep mine of this size.
Table 2 shows the estimated effect of oxygen free atmos-
phere on the average cost of construction of the 5,000
ton/day mine. No credit was taken for capital cost
increases in an air ventilated mine that may be required
to meet the conditions of the new Mine Health and Safety
Act. The cost for inert gas (nitrogen) generation and
storage would include the gas compression facility in the
case of the gassy mine.
The estimated operating costs are shown in Table 3. In
this instance, no effort was made to list those costs that
remain the same whether in air or in inert gas.
It is important to note that the added depreciation and
interest on the additional capital constitutes the major
portion of the increased costs of operation under an
oxygen free atmosphere. In the absence of natural gas
recovery, the increased operating cost is approximately
3% of the value of the coal produced. This amount may
well be offset by the increased costs proposed as
associated with the new safety act.
If natural gas can be recovered and sold at $0.30 per
thousand at the mine, the impact of this added income is
substantial and would obviously offset any reductions in
127
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mine efficiency that might occur using the oxygen free
atmosphere process.
It is apparent that the oxygen free atmosphere process
should be demonstrated to develop firm estimates of
capital and operating costs as well as productivity. It
is also apparent that the first applications of the
process are likely to be in highly gassy deep mines.
128
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TABLE 2
PROJECTED CAPITAL COSTS
Normal Air Without
Capital Costs Estimate Ventilation Oxygen
Item
Construction Cost includ-
ing Mining Equipment,
Coal Preparation
Facilities, and Site
Preparation $10 x 106 $10 x 10b
Non-Permissive Electri-
cal Equipment - (300,000)
200 Life Support Suits,
with Rebreather and
Emergency Pack - 300,000
200 Communication Units
with Headsets - 300,000
Inert Gas Generation
Storage and Distribution - 500,000
Air Conditioning and Dust
Control - 200,000
Refuges - 100,000
Instrumentation - 100,000
Net Capital Cost 10.0 x 106 $11.2 x 106
129
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TABLE 3
PROJECTED OPERATING COSTS
Operating Cost Estimate
Dollars/year
Normal Axr
Ventilation
Without
Oxygen
Item
Labor Cost @ $50/day
Total
Life Support Systems
Maintenance Suits, Packs
and Communication
Life Support Supplies, CO2
Absorbers, Oxygen, etc.
Electric Power
Rock Dust
Roof Bolts
Inert Gas, Air
Conditioning
TOTAL
Depreciation and Interest
2.3 x 10'
0.09 x 106
0.15 x 106
0.88 x 106
3.42 x 106
1.6 x 106
Sale Value of Coal Produced 7.2 x 106
Sale Value of Natural Gas
Recovered
2.1 x .10b
0.10 x 106
0.2 x 106
0.07 x 106
0.88 x 106
0.08 x 106
3.43 x 106
1.8 x 106
7.2 x 106
1.5 x 106
130
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SECTION XV
MINE SITE EVALUATION
The site to be selected for any proposed demonstration mine
must be on leases currently available for operation, must
be in a virgin seam in which there has been no other actual
mining activity surface or deep in the part of the seam to
be used, a minimum of 50" of seam height to allow reasonably
uncramped operation, a seam outcropping above grade so as
to allow drift entries, a non-gassy seam, and an active
mine with working entries within a reasonable distance so
that coal handling facilities, haulage, utilities and
roads may be shared. In addition, a good probability of
producing acid mine drainage during operation should exist.
Three leases. Red Jacket, Rock House, and Pond Fork, all
within a radius of Holden, West Virginia, belonging to
Island Creek Coal Company, met with the stated requirements
for the proposed demonstration mine site. Field water
samples were analyzed and laboratory column tests were run
on samples of refuse from the adjacent active mines.
One site is located in the drainage area of the Kanawha
River Basin in Boone County, West Virginia. The other two
sites are located in the drainage area of the Big Sandy
River watershed. All three sites are located as shown in
Figure 15.
Both watersheds lie in the geographical ridge areas desig-
nated as the Appalachian Plateau and Valley Ridge Provinces.
The region is geologically characterized by anticlines and
synclines with an associated Pennsylvanian type Paleozoic
rock classification. The general area contains great
thicknesses of sandstone and shale and some limestone beds.
As a result of such rock structure, coal is found in
abundance and a moderately large groundwater supply is
available.
The specific watershed of the first proposed site is the
Price Branch of Pond Fork of the Little Coal River which
flows into the Coal River, then to the Kanawha River, and
finally to the Ohio River. The Coal River is a lesser
tributary of the Kanawha River and is characterized as a
natural-flow stream. The junction of the Coal River is
below Charleston, West Virginia, along Zone 2 of the
Kanawha River. The Kanawha River is the fourth largest
131
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Co
I
FIGURE 15
WATERSHEDS - KANAWHA AND BIG SANDY RIVERS
-------
tributary to the Ohio River and joins it at Point Pleasant,
West Virginia. The Kanawha River and its tributaries drain
a 12,240 square mile area, of which 8,470 square miles lie
within West Virginia.
The Kanawha River from Charleston to Winfield, including the
mouth of the Coal River, is devoid of oxygen during low
stream flows in summer.
Very little water quality data for Price Branch of the Pond
Fork has been accumulated. Analytical data obtained to date
from U. S. Geological Survey published reports is included
in Table 4.
The second alternative is the Rock House Fork site near Rag-
land in Mingo County, West Virginia. The specific watershed
of this mine is the Slate Branch of the Rock House Fork of
Pigeon Creek. Pigeon Creek flows into the Tug Fork of the
Big Sandy River, which finally flows into the Ohio River.
The third alternative is the Mate Creek site near Red Jacket
in Mingo County, West Virginia. The specific watershed of
this mine is the Pats Branch of Mate Creek. Mate Creek flows
into the Tug Fork of the Big Sandy River at Matewan, West
Virginia which then flows into the Ohio River at Kenova,
West Virginia. The Big Sandy River drains an area of 4,280
square miles, of which 1,550 are drained by Tug Fork.
Again, very little water quality data has been accumulated
for the Slate Branch of Rock House Fork, Rock House Fork of
Pigeon Creek, Pats Branch of Mate Creek or Mate Creek.
Analytical data obtained to date from U. S. Geological
Survey published reports on Tug Fork, Pigeon Creek, and the
Big Sandy River is included in Table 5.
The Pond Fork site would remove coal from the Dorothy seam.
The true Dorothy seam is a member of the Kanawha Group, a
series of coal seams which have been and are now mined in
Boone County, West Virginia. The Kanawha Group seams lie
below the Freeport seams of the Allegheny Series and include
from the top:
No. 5 Block
Coalburg
Winifrede
Chilton
Hernshaw
Island Creek
Alma
133
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CO
TABLE 4
KANAWHA RIVER BASIN
Stream Sampling Site and
Drainage Area, in Sq. Mi.
(in Parenthesis)
Cherry River at Fenwick,
W. Va. (287)
Meadow River at Mallen,
W. Va. (287)
Kanawha River at Kanawha
Palls, W. Va. (8,367)
Loop Creek at Robson,
W. Va. (42.3)
Elk River at Queen Shoals ,
W. Va. (1,147)
Marsh Fork at Edwight,
W. Va. (128)
Pond Fork at Madison,
W. Va. (138)
Little Coal River at
Danville, W. Va. (270)
Big Coal River at Ashford,
W. Va. (393)
SOURCE: Biesiecker, J. E.,
Water Total Total
Discharge Aluminum Iron Manganese Bicarbonate Sulfate
Date (cfs) pH (Al) (Fe) (Mn) (HCOj) (SOQ
05-20-65
05-20-65
05-20-65 5
05-20-65
05-19-65
05-17-65
05-17-65
05-17-65
05-17-65
and J. R. George,
72
107
,070
14
287
64
64
117
153
7.4
7.3
7.4
.7 6.9
7.2
.9 7.6
.3 7.3
7.2
6.9
Stream Quality
as Related to Coal-Mine Drainage, 1965,
Geological
0.1
.1
.1
.1
.0
.2
.1
.1
.1
0.09
.07
.06
.02
.05
.02
.03
.04
.03
0.03
.03
.00
.82
.00
.17
.32
.21
.05
17
27
55
20
20
53
24
31
30
17
27
17
368
18
114
201
188
116
Sp. Cond.
(micromhoB
at 25°C) pH
75
115
138
762
84
360
490
485
331
7.4
7.2
7.2
7.1
7.2
7.6
7.2
6. 7
7.2
in Appalachia
Survey
Circular
526, Washington, 1966.
-------
CO
Cn
TABLE 5
BIG SANDY RIVER BASIN
Stream Sampling Site and
Drainage Area, in Sq. Mi.
(in Parenthesis)
Tug Fork at Roderf ield,
W. Va. (208)
Dry Fork at Laeger,
W. Va. (228)
Pigeon Creek at Naugatuok
W. Va. (142)
Tug Fork near Kermit,
W. Va. (1,185)
Rockcastle Creek at Clifford,
Ky. (121)
Russell Fork at Elkhorn City,
Ky. (554)
Levisa Fork at Fishtrap,
Ky. (386)
Shelby Creek at Shelbiana,
Ky. (110)
Beaver Creek at Martin,
Ky. (228)
Johns Creek near Van Lear,
Ky. (206)
SOURCE: Biesiecker, J. E., and
as Related to Coal-Mine
Water
Discharge Aluminum
Date
05-21-65
05-21-65
05-21-65
05-21-65
05-21-65
05-20-65
05-20-65
05-20-65
05-20-65
05-19-65
J . R . George
(cfs)
558
130
26.
468
23.
900
157
76.
138
27
PH
7.2
6.8
6 7.2
8.0
9 7.2
6.8
7.2
8 7.4
7.4
7.4
, Stream Quality
Drainage, 196 b,
Geological
(Al)
0.1
.1
.0
.2
0.0
3.1
.1
.1
.1
.1
Total Total
Iron Manganese
(Fe)
0.10
.08
.08
.18
0.22
.06
.07
.04
.08
.15
(Mn)
0.00
.02
.12
.03
0.05
.01
.00
.00
.16
.00
Bicarbonate
(HC03)
105
231
55
188
30
26
50
70
62
18
oulf ate
(SO 4)
77
68
334
165
18
30
173
91
104
16
Sp . Cond .
(micromhos
at 25°C>
351
580
843
690
165
120
471
324
359
85
PH
7.3
7.8
7.1
7.8
6.8
6.9
7.3
7.3
7.0
7.4
in Appalachia
Survey
Circular
526, Washington, 1966.
-------
No. 2 Gas
Powellton
Eagle
Douglas
There is a good deal of discrepancy in the existing litera-
ture regarding the Dorothy seam. According to Mr. Paul
Price, who is a retired consultant formerly with the West
Virginia Geological Survey/ the Dorothy is a premium seam
and is actually a split from the Winifrede seam. Because
of its high quality (0.6% S) and its attractive reputation
and market potential, small operators in the area sold coal
from less desirable seams, such as possibly the No. 5
Block, as being Dorothy coal. Additionally, very little
attention was paid by operators in actually identifying
specific seams. The Pond Fork mine seam is probably from
the Coalburg strata or a split therefrom. Both alternative
sites also remove coal from the Coalburg strata.
Examination of the diamond drill hole logs for the three
sites shows that no pyrites were identified in the log of
Pond Fork whereas some pyrites were located 85 feet above
the Coalburg seam for Rock House Fork. Pyrite is also often
concentrated in binders, sulfurballs, lenses, clays, shales,
and rider coal bands located in as well as immediately
above coal seams. Laboratory analyses of samples of binders,
sulfurballs, and lenses indicate that these materials are
often high in pyrite, occasionally as high as 94% pyrited2).
Quantitative analyses indicate that different strata vary a
good deal in total sulfur content(13), Analyses of several
strata follow:
Total Pyritic and Sulfate
Source Sulfur Sulfate Sulfur Sulfur
First Draw Slate 0.92 0.83
First Rider Coal 5.87, 6.41 5.32 0.51
Second Draw Slate 0.71 0.68
Bone 0.54
Third Rider Coal 8.55 7.97 2.43
Predicting whether any new coal mine will produce an acidic
water discharge during mining is risky. The drill logs of
the three sets as mentioned show minimal pyrites but also a
minimum of limestone above the coal.. The Dorothy seam is
low in sulfur but has not been extensively mined in the
areas concerned. The information available from the drilling
and other records, and from communication with the West
Virginia Department of Natural Resources, indicates a better
136
-------
than even chance that mining at either of the three sites
will eventually produce acid drainage.
Mine Drainage Quality - Published Data
Significant mine drainage pollution occurs in both the Coal
River and the Little Coal River (Pond Fork site). The 1969
Revision of "Stream Pollution by Coal Mine Drainage in
Appalachia," U.S.D.I., FWPCA, Cincinnati, Ohio(13?f states
that the entire 52 miles of Little Coal River and the
entire 96 miles of its tributaries are continuously
polluted by mine drainage. Sulfate concentrations in
excess of 250 mg/1 are frequently encountered in the Coal
River watershed.
Although no specific data on the quality of drainage from
Dorothy seam mines has been uncovered, some data (as early
as 1934) was presented on other seams than being mined in
Boone County.
Acreage of West Virginia Coal
Seams in Boone County - % Composition
Acreage % Sulfur
Lbs./Day
Acidity Acid
Lower Kittanning
Stockton
Coalburg
Winifrede
Chilton
Hernshaw
Williamson
Cedar Grove
Alma
No. 2 Gas
Powellton
Eagle
NR - Not Reported
37,152
57,632
54,598
163,968
148,544
208,000
12,800
238,592
253,056
230,016
19,200
19,200
1.33
0.86
0.80
0.65
0.75
3.13
1.82
0.61
1.32
1.51
0.97
0.86
200
250
350
100
Alk
Alk
NR
500
3,500
NR
NR
NR
1,500
68
11,750
745
NR
1,260
27,100
NR
NR
NR
It was further reported<14' in 1954, that the following
seams (known to be mined in Boone County) contained acidity
as ppm CaCOs:
Seam ppm Acidity as
No. 5 Block - Kanawha
Coalburg - Fayette
Winifrede - Mingo
500
350
100
137
-------
Seam ppm Acidity as CaCOji
Alma - Logan 3,500
No. 2 Gas - Kanawha 800
Many parts of the Kanawha Basin produce mine discharges
which are alkaline rather than acidic, due to the presence
of limestone or other alkaline deposits in the area. The
important indication of pyritic oxidation, however, is the
sulfate ion, which is incompletely or not reduced by such
neutralization processes.
It has been estimated(13) that approximately 500 miles of
streams in the Big Sandy River Basin (sites of Rock House
and Red Jacket) are polluted by coal mine drainage or
activities related to coal mining. The tributaries of Tug
Fork are apparently the most seriously affected with an
estimated 58 miles of streams continuously polluted by mine
drainage. Although these streams are, for the most part,
highly mineralize^ "arid often contain fine coal and silt,
they are not generally characterized by high acidity concen-
trations. The Tug Fork and Big Sandy River watersheds
reflect the influence of mine drainage in total mineraliza-
tion and high sulfate, iron and manganese concentrations.
In 1936(14), it was estimated that the drainage from an
average West Virginia coal mine amounted to approximately
1,000 gallons per acre per day. Using this information
along with the alkalinity-acidity determinations, the
following table of quantities of drainage and acid produced
were calculated:
Coal Mine Drainage in West Virginia
and Acid Produced by Seams
Drainage Acid
Searn^ (Gals, per Day) jLbs^j?er Day)
Sewickley 6,135,000 234,056
Redstone 2,684,000 26,204
Pittsburgh 50,228,000 1,304,956
Bakerstown 3,106,000 6,228
Upper Freeport 12,824,000 368,414
138
-------
Coal Mine Drainage in West Virginia
and Acid Produced by Seams (Cont'd)
Drainage Acid
Seam (Gals, per Day) (Lbs. per Day)
Upper Kittanning 1,789,000 16,370
Lower Kittanning 11,653,000 35,569
Stockton 1,468,000 2,988
Coalburg 7,870,000 34,649
Winifrede 13,777,000 11,248
Cedar Grove 28,583,000 654,410
Alma 9,992,000 108,220
Sewell 18,240,000 72,515
Total 168,349,000 2,875,827
SOURCE: Herndon, L. K., and W. W. Hodge, Coal Seams of West
Virginia and Their Drainage, Proc. West Virginia
Academy of Science, Vol. 9, pp. 39-61, Feb., 1936.
Coal Mine Drainage in West Virginia and
Acid Produced by Watersheds
Drainage Acid
Watersheds (Gals, per Day) (Lbs. per Day)
Monongahela 61,898,000 1,755,064
Ohio 11,592,000 177,879
Kanawha 48,289,000 157,363
Guyandotte 31,775,000 711,426
Tug - Big Sandy 11,511,000 53,470
Potomac 3,284,000 20,625
Total 168,349,000 2,875,827
SOURCE: Herndon, L. K., and W. W. Hodge, Coal Seams of West
Virginia and Their Drainage, Proc. West Virginia
Academy of Science, Vol. 9, pp. 39-61, Feb., 1936.
139
-------
Using these drainage and acid figures, and assuming that
the operations in the different seams would continue at
the same rate, the following was calculated for the annual
increase in acid production:
Estimated Annual Increase in Coal Mine Drainage
from Principal Acid Producing Seams
and Acid Production in West Virginia
Drainage Acid
Seam Acreage (Gals, per Day) (Lbs. per Day)
Sewickley 378 378,000 15,800
Redstone 50 50,000 48
Pittsburgh 2,200 2,200,000 62,000
Bakerstown 21 21,000 43
Upper Freeport 163 163,000 6,640
Upper Kittanning 19 19,000 77
Lower Kittanning 545 545,000 2,220
Stockton 21 21,000 43
Coalburg 118 118,000 396
Winifrede 478 478,000 390
Cedar Grove 2,510 2,510,000 71,800
Alma 293 293,000 8,370
Sewell 2,040 2,040,000 8,300
Total 8,836 8,836,000 176,127
SOURCE : Herndon , L . K . , and W . W . Hodge , Coal Seams of
West Virginia and Their Drainage, Proc. West
Virginia Academy of Science, Vol. 9, pp. 39-61,
Feb., 1936.
Another study completed in 1954, confirmed the acidity
of drainage reported from the Coalburg seam; however, it
has also been pointed out that all of the coal seams in
this area also produce alkaline drainage and some do so pre-
dominantly .
Mine Drainage Quality - Field and Laboratory Studies
Samples of mine drainage were collected from the three
proposed sites during the period October, 1969 - February,
1970. In addition, samples of coal refuse from mines in
the area of the three sites were collected for column
studies in the laboratory. The results of the analysis of
the field samples are shown in Tables 6, 7, and 8.
140
-------
TABLE 6
FIELD SAMPLE
POND FORK MINE DISCHARGE (SITE D)
Nov. Dec. Jan. Jan. Feb.
Date Sampled 26 12 5 15 23
M.O. Alkalinity (CaC03) 202 34 28 12 10
Total Acidity (CaCOs) 8 18 8 24
Chloride (Cl) 17 12.1 14.5 14.0 17.0
Sp. Conductance (25°C) mhos 405 140 125 101 97
pH 7.7 6.3 6.7 6.2 6.3
Calcium (Ca) 44.2 12.8 6.8 7.0 6.0
Magnesium (Mg) 23.5 11.5 7.2 5.0 6.0
Hardness (CaCOs) 208 80 46 38 40
Sulfate (S04) 27.5 28.1 46.9 28.6
Total Iron (Fe) 0.47 5.62 0.74 0.61 0.42
Total Aluminum (Al) 0.26 0.49 0.03 0.58 0.60
Manganese (Mn) 0.05 0.05 0.05 0.07 0.06
-------
TABLE 7
FIELD SAMPLE
ROCK HOUSE MINE DISCHARGE (SITE E)
Nov. Dec. Jan.
Date Sampled 26 12 5
M.O. Alkalinity (CaCOs) 62 74 68
Total Acidity (CaCOs) 3 12 10
Chloride (Cl) 13.0 12.1 15.8
Sp. Conductance (25°C) itimhos 225 250 235
pH 7.8 6.8 6.9
Calcium (Ca) 19.2 27.2 23.0
Magnesium (Mg) 13.4 12.5 11.5
Hardness (CaCOs) 104 120 106
Sulfate (504) 44.5 39.7
Total Iron (Fe) 1.33 8.45 0.14
Total Aluminum (Al) 0.92 0.06 0.13
Manganese (Mn) 0.05 0.05 0.06
-------
TABLE 8
FIELD SAMPLE
RED JACKET MINE DISCHARGE (SITE F)
Nov. Dec. Jan. Jan. Feb.
Date Sampled 26 12 5 15 23
M.O. Alkalinity (CaCOs) 44 66 68 68
Total Acidity (CaCOs) 6 10 4 66
Chloride (Cl) 15.8 15.8 18.2 24.0 20.0
Sp. Conductance (25°C) mmhos 190 215 350 530 290
PH 7.1 7.1 7.3 7.6 7.4
Calcium (Ca) 16.8 30.0 47.0 54.0 27.0
Magnesium (Mg) 6.7 5.8 7.7 25.0 7.0
Hardness (CaCOs) 70 100 150 238 96
Sulfate (S04) 34.2 75.0 106.0 53.5
Total Iron (Fe) 0.86 0.32 0.21 0.32 0.59
Total Aluminum (Al) 0.30 0.36 0.01 0.26 0.54
Manganese (Mn) 0.05 0.05 0.05 0.08 0.05
-------
The coal refuse samples were ground to 8 x 30 mesh and
loaded in three columns as shown in Table 9. Analyses
of the coal refuse samples is shown in Table 10. The test
column flow sheet is shown in Figure 16. Tests for
conductivity and pH were made daily on the column effluent.
Once per week samples of effluent were collected and
analyzed more completely. The results of the weekly
analyses are shown in Tables 11, 12, and 13. The results
of the daily tests are plotted in Figures 17, 18, and 19.
The columns were in operation from November, 1969 through
February, 1970.
Summary of Factors
The following are factors affecting a conclusion as to the
most desirable site of those examined from a drainage
quality viewpoint for a proposed demonstration mine:
1. The Dorothy seam (a split from the Winifrede seam) or
the Coalburg seam, while of uncertain identity, geographi-
cally speaking, have never been cited as large acid producers
even though they are known to produce acid.
2. The presence of limestone deposits in the Kanawha River
drainage area lessens the chances of serious acid drainage
pollution problems.
3. Although the core samples of the Rock House Fork site
definitely indicate the presence of pyritic material, this
may well be a local condition and may not exist as a
continuous or widespread strata.
4. The absence of limestone or other alkaline material,
along with the presence of pyrite in the overburden, might
reasonably lead one to believe that any drainage eminating
from this Coalburg seam would be of a rather poor quality.
5. Nearby mines, draining into Pond Fork, Price Creek and
other streams produce an acidic discharge.
6. The general watershed of both Little Coal River and Coal
River are considered to be continuously polluted by drainage
from mines. Since many seams are currently under mining
operations, and the true Dorothy seam is not completely
identified, one might well conclude that existing Dorothy
seam mining is now producing an acidic or alkaline drainage
high in sulfate content.
7. The laboratory column studies show that the Pond Fork
site refuse produces mildly acid drainage while the other
144
-------
THROTTLING VALVES
WATER
AID. to-
SCRUBBER
HUMIDIFIER
C
CAPILLARY
b
J
FILTER
I 1
r ^
|
/
\
s
\
\
TUBE COILS^
EACH COIL- 250' LONG
0.032 |.D. POLYETHYLENE
COLUMNS "I.D.X60"
FRITTED GLASS SUPPORT-^-
COLUMN
*l 745 CM3 FILL
335 CM3 VOID VOL.
410 CM3 SOLIDS
#2 739 CM3 FILL
295 CM3 VOID VOL.
444 CM3 SOLIDS
#3 750 CM3
325 CM3
425 CM3
/
1
>N •.
FILL
VOID VOL.
SOLIDS ft
.0 RECEIVING
VESSELS
/
^
/
r
V_
\
^
.j
\
y
I
^n
— v
\
Ni
)
'/
/
/
/
/
/
y
/
/
/
/
/
-V
J
X
I
\V&ik
X
FIGURE 16
TEST COLUMN ARRANGEMENT
145
-------
.1.
O)
>
K
>
S8
if
SE
II
o
to
o
10
o
CM
CONDUCTIVITY mmhos
30 40 50
VOLUME = LITERS
70
80
FIGURE 17
REFUSE SAMPLE, POND FORK (SITE G)
COLUMN EFFLUENT
-------
-
i
X
a
t
>
t-
o
§1
o c
II
O
O
in
O
-«
o
ro
!=! ro
O CJ
CONDUCTIVITY mmhos
30 40 50
VOLUME = LITERS
FIGURE 18
REFUSE SAMPLE ROCKHOUSE FORK (SITE H)
COLUMN EFFLUENT
-------
'™T~ . 1i:
CONDUCTIVITY mmho
40 50
VOLUME = LITERS
FIGURE 19
REFUSE SAMPLE, RED JACKET (SITE I)
COLUMN EFFLUENT
-------
TABLE 9
COLUMN TEST CONDITIONS
Columns: 1" (2.54 cm) diam. x 60" (152 cm) with fritted
glass support
Loading
#1
Site
Pond Fork
Rock House
Red Jacket
Water
Air
146.6 cm depth*
745.0 cm3 fill vol.
335.0 cm3 void vol.
410.0 cm3 solids vol.
145.4 cm depth*
739.0 cm3 fill vol.
295.0 cm3 void vol.
444.0 cm3 solids
147.6 cm depth*
750.0 cm3 fill vol.
325.0 cm3 void vol.
425.0 cm3 solids vol.
- demineralized
0.5 - 0.6 cc/min. rate
- water washed and humidified
3.0 - 4.0 cc/min.
*Backwashed and drained
149
-------
TABLE 10
COAL REFUSE SAMPLES
Pond Rock Red
Items Fork House Jacket
Silica (Si02) 31 37 32
Iron (Fe203) 0.5 0.5 0.5
Calcium (CaO) 11 l
Magnesium (MgO) 11 l
Sulfur (303) 1.0 1 1
Aluminum (A1203) 11 15 13
Chlorine (Cl) 11 l
*****
X-ray Diffraction
Silicon Dioxide
ASTM 12-708 15 15 10
Alpha Quartz
ASTM 5-490 15 15 10
Results reported as percent
150
-------
TABLE IX
POND FORK REFUSE - COLUMN EFFLUENT (SITE G)
1969-1970
Date Sampled
Volume, Cumulative
liters
M.O. Alkalinity (CaCOa)
Total Acidity (CaCOa)
Chloride (CD
Sp. Conductance (25°C)
mmhos
PH
Calcium (Ca)
Magnesium (Hg)
Hardness (CaC03)
Sulfate (S04)
Total Iron (Fe)
Total Aluminum (Al)
Manganese (Mn)
NOV.
17
2.2
2.3
2.0
4.0
48.1
4.7
1.6
3.8
19.6
0.049
0.12
<0.05
Nov.
24
7.9
2.3
4.0
4.0
30.2
4.7
0.4
0.7
3.9
0.024
0.12
<0.05
Dec.
1
13.0
2.0
2.0
13.3
21.0
4.9
2.0
0.7
5.0
0.020
0.020
<0.05
Dec.
8
2.0
3.0
13.3
20.0
4.5
0.4
0.8
4.4
0.032
0.11
<0.05
Dec.
15
21.5
4.0
2.0
9.7
17.5
4.6
1.2
1.2
8.0
39.0
0.048
0.015
<0.05
Dec.
23
28.8
4.0
2.0
12.1
16.5
4.6
0.2
0.4 .
2.4
18.3
0.061
0.071
<0.05
Dec. Jan.
29 6
30.3 38.7
2.0 2.0
3.0 2.0
12.1 10.9
16.0 14.0
4.7 4.6
0.5 0.6
0.4 0.8
2.8 4.6
12.2 11.6
0.034 0.063
0.050<0.01
<0.05 <0.05
Jan.
14
44.8
2,0
1.0
14.5
20.0
4.9
0.2
0.4
2.0
8.5
0.019
<0.01
<0.05
Jan.
19
48.2
6.0
2.0
8.0
13.0
5.5
0.1
0.4
1.9
25.6
0.012
0.018
<.05
Jan.
26
53.3
2.0
1.0
3.6
13.5
4.8
0.1
1.0
4.4
0.018
0.046
0.06
Feb.
3
58.9
1.0
1.0
10.9
13.5
4.7
0.2
0.3
1.8
3.03
0.005
0.03
0.11
Feb.
9
64.1
2.0
1.0
13.3
13.0
4.6
0.2
0.2
1.6
2.73
0.008
<0.01"
<0.05
Feb.
16
69.3
6.0
2.0
12.0
12.5
4.7
0.4
9.17
0.005
0.05
<0.05
Feb.
23
74.2
4.0
2.0
13.3
7.5
6.0
0.4
0.4
2.8
0.15
0.005
0.04.
<0.05
-------
TABLE 12
ROCK HOUSE FORK REFUSE - COLUMN EFFLUENT (SITE H)
Ol
Date Sampled
Volume, Cumulative
liters
M.O. Alkalinity (CaCOa)
Total Acidity (CaC03)
Chloride (Cl)
Sp. Conductance (25°C)
mmhos
PH
Calcium (Ca)
Magnesium (Mg)
Hardness (CaCOj)
Sulfate (804)
Total Iron (Fe)
Total Aluminum (Al)
Manganese (Mn)
1969-1970
Nov.
17
2.2
12.0
2.0
4.0
31.3
6.7
0.8
2.0
0.094
1.0
Nov.
24
7.8
4.6
2.0
4.0
23.1
6.4
0.4
0.7
0.59
1.5
Dec.
1
12.8
8.0
2.0
16.9
13.0
7.1
0.6
0.4
3.2
0.040
0.14
Dec.
8
8.0
2.0
14.5
13.0
6.7
0.3
0.8
4.2
0.097
0.08
Dec.
15
21.0
6.0
1.0
13.3
11.0
6.2
0.5
0.4
3.0
39.0
0.049
0.08
Dec.
23
28.1
6.0
2.0
13.3
10.0
6.7
0.5
0.2
2.0
14.6
0.034
0.13
Dec.
29
29.7
4.0
1.0
10.9
9.6
6.2
0.6
0.2
2.4
8.5
0.010
<0.01
Jan.
6
36.7
4.0
1.0
13.3
8.0
6.2
0.5
0.2
2.0
4.9
0.051
0.07
Jan.
14
42.8
6.0
1.0
15.6
8.0
6.5
0.4
0.2
2.0
4.3
0.011
<0.01
Jan.
19
46.2
1.0
2.0
8.0
7.4
6.7
<0.1
0.5
2.0
19.5
0.010
<0.01
Jan.
26
51.2
4.0
1.0
2.4
8.8
6.6
<0. 1
1.6
6.1
<0.05
0.012
0.05
Feb.
3
56.9
2.0
1.0
9.7
7.0
6.3
0.2
0.2
1.4
<0.05
0.008
0,07
Feb.
9
62.0
6.0
1.0
12.1
6.6
6.3
0.3
0.2
1.6
3.90
0.011
<0.01
Feb.
16
67.1
2.0
2.0
12.0
6.5
6.2
0.4
<0.05
0.018
0.03
Feb.
23
72.1
6.0
1.0
13.3
6.0
6.5
0.4
0.1
1.6
0.24
0.014
<0.01
0.02
-------
TABLE 13
RED JACKET REFUSE - COLUMN EFFLUENT (SITE I)
01
to
Date Sampled
Volume, Cumulative
liters
M.O. Alkalinity (CaCOa)
Total Acidity (CaCOs)
Chloride (Cl)
Sp. Conductance (25°C)
iranhos
pH
Calcium (Ca)
Magnesium (Mg)
Hardness
Sulfate (S04)
Total Iron (Fe)
Total Aluminum (Al)
Manganese (Mn)
1969-1970
Nov.
17
2.2
16.0
2.0
4.0
52.5
7.3
2.4
1.9
13.8
0.040
0.18
O.05
Nov.
24
8.0
9.2
2.0
4.0
31.7
6.7
1.5
1.0
7.9
0.009
0.04
<0.05
Dec.
1
13.0
14.0
2.0
15.7
30.0
7.3
2.6
1.3
12.0
0.003
0.02
<0.05
Dec.
8
16.0
2.0
15.8
29.0
7.1
2.1
1.2
10.2
0.020
0.06
<0.05
Dec.
15
21.1
12.0
4.0
12.1
23.0
6.6
1.8
0.9
8.4
23.2
0.029
0.02
<0.05
Dec.
23
28.2
10.0
2.0
13.3
20.0
7.1
2.0
1.2
10.0
15.9
0.039
0.07
<0.05
Dec.
29
29.8
10.0
2.0
12.1
20.0
6.2
1.9
0.8
8.2
X14.6
0.013
<0.01
<0.05
Jan.
6
39.2
10.0
1.0
12.1
17.0
6.5
2.2
0.4
7.2
7.3
0.010
O.01
<0.05
Jan.
14
45.5
8.0
2.0
14.5
15.0
7.0
1.7
0.5
6.4
7.9
0.008
<0.01
<0.05
Jan.
19
48.9
4.0
2.0
12.0
15.0
7.0
0.8
1.4
7.7
31.7
0.009
<0.01
<0.05
Jan.
26
54.1
5.0
1.0
17.0
6.9
0.9
2.2
11.3
<0.05
0.006
0.04
0.08
Feb.
3
59.8
8.0
1.0
14.5
14.0
6.8
1.3
0.5
5.4
<0.05
0.007
0.08
0.06
Feb.
9
65.7
4.0
1.0
13.3
14.0
6.5
1.2
0.4
4.6
0.98
0.009
<0.01
<0.05
Feb.
16
70.4
4.0
2.0
18.0
11.3
6.9
1.6
5.56
0.005
0.02
<0.05
Feb.
23
76.9
8.0
1.0
15.8
10.8
6.7
1.3
0.3
4.6
4.6
0.001
<0.01
<0.05
-------
two do not. The Red Jacket effluent was highest in hardness
and sulfate.
8. The field samples from the three sites were not acidic
and were very similar in overall quality; the pH from Pond
Fork was slightly lower than the other two; sulfates were
highest in the Red Jacket samples.
9. The refuse analyses showed all three low in sulfur with
Pond Fork refuse containing slightly more sulfur than the
rest.
Final Selection
The conclusions drawn from the foregoing are that there is
better than an even chance that the mine drainage from the
Pond Fork site will be mildly acid and that this factor
coupled with a favorable position and seam height for the
area of the seam that could be used for the test result in
the selection of the Pond Fork site for the proposed
demonstration mine.
154
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SECTION XVI
EXTERNAL SYSTEMS AND FACILITIES
The proposed demonstration mine if constructed at the
selected site would be located near but separate from the
Island Creek Coal Company's Pond Fork Mine (See Figure
20) . The external facilities while peculiar to the
selected site and smaller than those for a full scale mine
are typical of the facilities required for an oxygen free
atmosphere mine.
Site Preparation
The access road and part of the grading for the demonstra-
tion mine site will have been completed by work done in the
course of surface mining along the contour by a contract
surface miner. The level area available for the outside
facilities (Figure 21) will be approximately 125 feet wide
and 700 feet long. The face of the high wall over the
demonstration mine openings is a sandstone, and the top
makes up for good roof control, a very short distance
inside the openings.
Power Supply
Power is currently metered at a source about 6000 feet from
the demonstration mine openings at twelve (12) KVA. A power
line of 12 KVA capacity would be installed and the power
conveyed from auxiliary transformers at 4160 volts for use
inside the demonstration mine and for the outside associated
facilities.
Water Supply
Water would be acquired by drilling a well and pumping the
water to a storage tank to supply water for gas generation,
inside mine use in the refuge station and use in surface
buildings. Should there be a problem of water shortage by
well drilling, an alternate water supply is available 6000
feet from the demonstration mine at Island Creek Coal
Company's Pond Fork Mine, and could be piped by gravity to
the demonstration mine site. The well water would be
treated as required for potable usage.
155
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i
N
FIGURE 20
MINE LOCATION MAP
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I 2 COMPARTMENT COAL BIN
2 MAINTENANCE AND TESTING
3 OFFICE BUILDING
4 SUPPLY YARD
5 SUPPLY BUILDING
6 INERT GAS GENERATOR
7 INERT GAS STORAGE BUILDING
8 COOLING TOWER
9 FAN
10 AIR CONDITIONER
II TRANSFORMER
12 COAL CONVEYOR
13 2-10" BORE HOLES
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157
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Office and Control Building
The main office, Figure 21, would be a metal building
approximately 60 feet long and 30 feet wide. This building
would be partitioned off in areas to accommodate the mine
foreman, time clerk, mining engineer, chemical engineer,
non-oxygen room for testing suits, study room, room for
storing life support equipment, change room with lockers for
personal clothes and belongings, and a shower room with
toilets and lavatories. This building would be set on a
concrete base and trimmed inside with suitable material to
accomplish the task demanded of that particular room.
Adequate sewage treatment would be an integral part of this
building. Heat would be of the baseboard electrical type.
Maintenance and Testing Shop
The shop, Figure 21, would be a metal building 60 feet long
by 24 feet wide, and would have the battery charging
station as well as the batteries on charge. Batteries would
be handled by an overhead traveling crane. Another area,
totally enclosed and heated, would act as a repair shop and
a training area as well as serve as an area for all types
of testing of materials and equipment necessary in the
proposed demonstration mine program. Heat in this building
would be electrical-blowing space type heaters.
Storage Facilities
Storage for all types of mine supplies, Figure 21, would be
housed in a steel building approximately 40 feet long and
20 feet wide with a truck height platform to make unloading
of supplies as easy as possible. Bins for different types
of supplies would be provided so that easy access is
afforded as well as maintenance of an accurate running
inventory. Timbers would be stored in rows as shown in
Figure 21, in a manner that trucks, delivering these
timbers, could back between rows and unload. The supply
cars taking timbers into the mine could back into the same
stalls for easy loading. The storage of life support
units would be handled in the main office and control build-
ing.
158
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SECTION XVII
ACKNOWLEDGMENTS
The excellent cooperation and technical assistance of L.
E. Day and A. F. Phillips of the National Aeronautics
and Space Administration is gratefully appreciated.
The assistance of J. R. Fleming, Manager Product Develop-
ment, and C. Leffler of Arrowhead Products Division,
Federal-Mogul Corporation; of D. Curtis, Manager of
Research, Applied Technology Division, Litton Systems,
Inc.; of C. H. Staub, Director Marketing Division, MSA
Research Corporation; and of R. Clew, Bendix Launch
Support Division, Cape Kennedy is acknowledged with
sincere thanks.
To William Bellano, then President and Chief Administrative
Officer of Island Creek Coal Company, our grateful apprecia-
tion for recognizing the potentials of this new technology.
Mr. Stonie Barker, Jr., W. F. Diamond, and R. C. Taliaferro
of Island Creek Coal Company, who with their project
associates J. K. Rice and D. J. Motz of Cyrus Wm. Rice
Division, NUS CORPORATION, directed and guided this Phase
I engineering feasibility program.
The support and technical advice of the United States
Bureau of Mines, and their program representative Milton
Skow is gratefully acknowledged.
The support of the project by the Federal Water Quality
Administration and the excellent technical guidance pro-
vided by A. Cywin, E. P. Hall, and D. J. 0'Bryan, Jr.,
the Grant Project Officer, is acknowledged with grateful
appreciation.
159
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SECTION XVIII
REFERENCES
1. Braley, S. A., "Summary Report of Commonwealth of
Pennsylvania, Department of Health Industrial Fellow-
ship, No's 1 through 7," Mellon Industrial Fellowship
No. 326B, 1954.
2. Bell, W. E., "Studies of the Effect of Gas Atmospheres
on Pyrite Oxidation," Final report under Federal Water
Quality Administration Contract No. 14-12-404 to Cyrus
. Wm. Rice Division, NUS CORPORATION, Pittsburgh,
Pennsylvania, April, 1969.
3. "Gas Requirements to Pressurize Abandoned Deep Mines-
A Study of the Use of Inert Gases to Eliminate Acid
Pollution from Abandoned Deep Mines," A report of the
Commonwealth of Pennsylvania, Department of Mines and
Mineral Industries under Project No. CR-81, Federal
Water Quality Administration Project No. WPRD-227,
1968.
4. "Space Cabin Atmospheres Part 1 - Oxygen Toxicity,"
National Aeronautics and Space Administration SP-47,
1964.
5. "Bioastronautics Data Book," National Aeronautics and
Space Administration SP-3006, 1964.
6. "Space Cabin Atmosphere Part 3 - Psychological Factors
of Inert Gases," National Aeronautics and Space
Administration SP-117, 1967.
7. "Portable Life Support Systems," Ames Research Center
Conference, May, 1969, National Aeronautics and Space
Administration SP-234, 1970.
8. Jackson, J. K., and Blakely, R. L., "Application of
Adsorption to Spacecraft Life Support Systems," Missile
and Space Systems Division, Douglas Aircraft Company,
Inc.
9. Mills, E. S., G. V. Colombo, and R. A. Neustein,
"Evaluation of Carbon Dioxide Sorption Techniques for
Hydrospace Application," Douglas Aircraft Company,
Independent Research and Development Program, Account
No. 81641-001.
161
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10. "Engineering Criteria for Spacecraft Cabin Atmosphere
Selection," Advanced Biotechnology and Power Department,
Missile and Space Systems Division, Douglas Aircraft
Company, Inc., Douglas Report DAC-59169, November,
1966, under National Aeronautics and Space Administra-
tion Contract No. NASW1371.
11. Potter, A. E., Jr., and B. R. Baker, "Static Electricity
in the Apollo Spacecraft," Manned Spacecraft Center,
Houston, Texas, National Aeronautics and Space
Administration Report No. TND-5579, December, 1969.
12. Lorenz, Walter C., and Edward C. Tarpley, "Oxidation
of Coal Mine Pyrites," Bureau of Mines RI 6247, 1963,
13 pp.
13. "Stream Pollution by Coal Mine Drainage in Appalachia,"
U.S.D.I., FWQA, Cincinnati, Ohio, Revised 1969.
14. Herndon, L. K., and W. W. Hodge, "Coal Seams of West
Virginia and Their Drainage," Proc. West Virginia
Academy of Science, Vol. 9, pp. 39-61, Feb., 1936.
15. "Drainage From Bituminous Coal Mines," Research
Bulletin No. 25, West Virginia University Bulletin.
162
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SECTION XIX
PUBLICATIONS
1. Rice, J. K., and R. C. Taliaferro, "Mining in an Inert
Atmosphere," Presented at the 1970 Coal Convention and
Exposition, American Mining Congress, Cleveland, Ohio,
May, 1970.
2. Rice, J. K., "The Use of Inert Gas to Eliminate Acid
Pollution by Abandoned Active Deep Mines," Presented
at the Third Symposium on Coal Mine Drainage Research,
Pittsburgh, Pennsylvania, May, 1970.
3. "Inert Atmosphere in Mines Could Abate Acid Drainage,"
Chemical and Engineering News, 48, May 18, 1970,
pp. 33-35.
4. Rice, J. K., "Health and Safety When Mining in an Inert
Gas Atmosphere," Statement to the Subcommittee on Labor,
Senate Committee on Labor and Public Welfare on Coal
Mine Health and Safety, 1969.
5. Rice, J. K., "Acid Mine Drainage Abatement from Deep
Mines by Inert Gas Blanketing," Testimony before Water
Pollution Advisory Board, Pittsburgh, Pennsylvania,
1968.
163
* U. S. GOVERNMENT PRINTING OFFICE : 1970 O - 409-917
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