MINE GASES

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MINE GASES
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Normal Air is made up of
Nitrogen 78 Oxygen
21 Trace Gases 1
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Specific Gravity

• The weight of a gas compared to an equal volume
  of normal air at the same temperature and
  pressure.
• Normal air has a specific gravity of 1
• This determines where in mine atmospheres, or
  within a confined space, we will find
  concentrations of particular gases

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Examples
Carbon Dioxide 1.529 floor to
mid drift Hydrogen 0.0695
against back or roof Oxygen
1.105 evenly distributed Hydrogen
Sulfide 1.2 floor to mid
drift Carbon Monoxide 0.967
evenly distributed Sulfur Dioxide
2.264 floor
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Gases can and do pool Gases tend to flow as
fluids in quantity These effects can displace
Oxygen.
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Ventilation
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Heavier gases are harder to ventilate than
lighter gases. WHY?
What are we ventilating with?
Normal Air specific gravity of 1.0
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THE EXPOLSIVES!
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Methane 5-15 Carbon
Monoxide 12.5-75 Hydrogen
4-74 Hydrogen Sulfide
4.3-45
Hazards of ventilating concentrations of any of
these are IGNITION SOURCES! MOVING IRRESPIRABLE
GAS!
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THE LAW!
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In a mine or within a confined space, what is the
minimum percentage of Oxygen necessary?
19.5
Anything less means VENTILATE!
Most digital Oxygen detectors are set to alarm at
19.5
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THE QUIZ!
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Which gas has the greatest specific gravity? A.
Sulfur Dioxide B. Carbon Dioxide C. Oxygen D.
Nitrogen Dioxide
A. Sulfur Dioxide
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The explosive range of Hydrogen is? A. 5 - 15
B. 12.5 - 75 C. 4 - 45 D. 4 - 74
D. 4 - 74
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Which of the following gases are liberated from
underground diesel equipment?
A. Carbon Monoxide B. Carbon Dioxide C. Hydrogen
Sulfide D. All of the above
Carbon Monoxide and Carbon Dioxide
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Which gas has an acidic taste in high
concentrations?
Carbon Dioxide
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Which of the following gases are explosive? A.
Methane B. Oxygen C. Carbon Dioxide D.
Nitrogen E. Carbon Monoxide F. Hydrogen
Sulfide G. Hydrogen
Methane, Carbon Monoxide, Hydrogen Sulfide
Hydrogen
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What gases and what percent of each make up
normal air?
Nitrogen 78 Oxygen
21 Trace gases 1
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If you are ever concerned regarding the air
quality in any area of the mine or on the
surface MAKE SURE Your life and the person who
finds you depends on YOU If there are no gas
detection instruments immediately available, DO
NOT ENTER! VENTILATE