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Gases Flashcards

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1
Q

Name 8 gases relevant to the coal mining industries, chemical symbol, and specific gravity.

A

Name of Gases Chemical symbol Specific gravity
Hydrogen H2 0.07
Methane CH4 0.55
Carbon monoxide CO 0.97
Oxygen O2 1.11
Hydrogen Sulphide H2S 1.18
Carbon Dioxide CO2 1.52
Nitrogen Dioxide NO2 1.6
Sulphur Dioxide SO2 2.2

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2
Q

Oxygen. Explain the effect.

A

A. 16-14%- Slight increase in pulse and breathing rate, night and colour vision and judgement affected, Abnormal fatigue upon exertion
B. 14-10%- Poor judgement, abnormal fatigue upon exertion
c. 10-6%- Nausea, vomiting, inability to move or cry out, loss of consciousness may occur.

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3
Q

Minimum concentration of oxygen which coal mine worker can be exposed

A

19.5%

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4
Q

Gases that constitute normal air & percentages

A 
Oxygen	                      20.95 %
Nitrogen	                     78.08 %
Carbon dioxide	      .04 %
Argon/Inert gases	  .93 %
Water vapour	         0-3%
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5
Q

What percentage of oxygen

a) Flammable liquid cease
b) All flaming combustion ceases
c) All combustion ceases

A

Flammable liquid cease 17%
All flaming combustion ceases 10-12%
All combustion ceases 2%

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6
Q

What effect does atmosphere enriched with oxygen have on Upper flammable limit.

A

Expands the flammable limits of a flammable gas.

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7
Q

Name 2 Gases released when blasting.

A

Nitrogen dioxide

Carbon Monoxide

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8
Q

How do you identify if nitrogen dioxide has been released in a blast

A

Reddish brown colour in gas fume.

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9
Q

For nitrogen dioxide what is the:
TWA
STEL
IDHL

A

TWA- 3ppm (0.0003%)
STEL- 5ppm
IDHL- 20ppm

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10
Q

Name 4 signs or symptoms of exposure to Nitrogen Dioxide.

A
  1. Feeling ill
  2. Coughing violently
  3. Symptoms of bronchitis and pneumonia
  4. Death
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11
Q

Carbon Dioxide

A person must not be exposed to an atmospheric concentration at a coal mine containing a general body concentration of carbon dioxide exceeding?

and convert the % to ppm of above:

A

a) TWA of 1.25% - 12500 ppm

b) STEL 3.0 % - 30000 ppm

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12
Q

Explain the effect of the following CO2 concentrations on a person:

a) 2%-
b) 4.5-5%
c) 10%

A

a) 2%- 50% increase in lung ventilation
b) 4.5-5%- Anxiety, panic, irritability
c) 10%- Toxic, depresses CNS, violent panting, exhaustion, headache

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13
Q

Carbon dioxide is regarded as a hot gas due to its low thermal conductivity, explain:

A

Due to its insulating properties it gives a feeling of warmth

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14
Q

Carbon dioxide:

a) How is it produced
b) Where is it found in a coal mine

A

a) OXIDISATION of COAL and CARBONACEOUS MATERIAL, diesel exhausts, blasting operations, fires
b) Diesel exhausts, fires, spon com, fire fighting inert gas, Breathing..

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15
Q

Describe the physical and chemical properties of CO2:

A

Colourless, slight pungent odour. Soda water taste.

Non-flammable.

SG of 1.52

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16
Q

Describe the physiological effects of carbon dioxide at high and low concentrations

A

Low- STIMULATES the CNS. (Central Nervous System)

High-DEPRESSES the CNS
Affects lungs and breathing passage

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17
Q

Is CO2 a flammable gas

A

Not Flammable

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18
Q

State the long-term exposure limit concentrations for:

a) Carbon Monoxide
b) Hydrogen Sulphide
c) Sulphur dioxide
d) Nitrogen Dioxide

A

a) Carbon Monoxide: 30ppm
b) Hydrogen Sulphide: 10ppm
c) Sulphur dioxide: 2ppm
d) Nitrogen Dioxide: 3PPM

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19
Q

Carbon Monoxide

How is the body poisoned by CO Carbon monoxide

A

CO is absorbed 300 times more readily than 02 and prevents 02 from binding to the red bloods cells.

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20
Q

In regard to CO what is meant by the term “blood saturation”

A

Blood becomes saturated with CO preventing the blood from taking on any more O2 or CO

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21
Q

CO is said to have a cumulative effect. What is meant by cumulative effect

A

CO can build up in a person from multiple, small exposures to CO,

Making the person more susceptible to its effect.

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22
Q

4 Examples of how CO is produced in a coal mine

A

OXIDISATION
HEATINGS / FIRE
EXPLOSIONS
DIESEL ENGINES

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23
Q

Is CO an explosive gas

And at what concentration

A

Yes – 12.5% to 74.% explosive range

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24
Q

Name 6 signs or symptoms of CO poisoning

A 
Impairment of visual threshold, 
Unsteady gait, 
Becoming silent,
Rosy/Flushed Face, 
Heavy feeling in legs, 
Headache, nausea
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25
State the chemical & physical properties of CO
HIGHLY POISONOUS GAS C. O. T. FLAMMABLE GAS SG of 0.97.
26
Methane What is the ignition temperature of Methane
537 C. - Aust Standard
27
What is the MINIMUM concentration of OXYGEN (at norm temp) for methane explosion to occur
12.2%
28
Is methane poisonous
NOT POISONOUS but WILL NOT SUPPORT LIFE
29
State physical and chemical properties of methane
Colourless, Odourless,Tasteless Flammable gas. CH4 - SG of 0.55.
30
What is the explosive range of methane (in normal air and temp)
5-15%
31
What is the most easily ignited % of methane from a HEATED SURFACE in a mixture of CH4 and air
5-6%
32
Explain “lag on ignition”
The time period that a FLAMMABLE GAS MIXTURE is in contact with a HEAT SOURCE prior to an IGNITION taking place. DEPENDENT on CONCENTRATION of GAS and TEMPof HEAT SOURCE.
33
What is the lag on ignition for methane at 5-6%
2secs
34
Explain how methane is produced + Where it is found
Produced naturally during the PEAT to LIGNITE transformation Found in almost all coal and some coal bearing strata.
35
What effect can the presence of coal dust suspended in the atmosphere have on the LEL of methane
Can lower LEL from 5 - 0%
36
What % of METHANE is recognised as the MOST EXPLOSIVE in AIR
9.5% of MIXTURE
37
What effect does the increase in ambient temp have on a flammable gas/air mixture
Increase in Explosive Limit of the Upper Explosive Limit (UEL) Decrease in Explosive Limit of the Lower Explosive Limit (LEL)
38
Hydrogen Sulphide State where H2S can be found at a coal mine
Stagnant water, Spon com in coal containing PYRITES, Seam gas
39
What concentration of H2S causes dizziness, excitement, nausea, dryness & pain in the nose, throat chest and irritation of the mucous membranes
250-600ppm
40
Explain the physical & chemical properties of H2S
``` TOXIC COLOURLESS ROTTEN EGG SMELL SWEETISH TASTE H2S - SG 1.18- Flammable ```
41
State the physiological effects of H2S on a person
Toxic gas. | IRRITATES the EYES and RESPIRATORY TRACT and has a NARCOTIC EFFECT on the NERVOUS SYSTEM.
42
Is H2S flammable and a what percentage in air
It has an AUTO IGNITION TEMP of 260°C | FLAMMABLE RANGE 4.3% - 45%
43
Sulphur Dioxide State the chemical & physical properties of SO2
``` : Toxic. -NF Colourless SUFFOCATING PUNGENT odour Almost intolerable acidic taste. SG of 2.2. - SO2 ```
44
State the physiological effects of SO2 has on a person
EXTREMELY POISONOUS Affects LUNGS IRRITATES EYES and RESPIRATORY PASSAGE INTOLERABLE to BREATHE at certain concentrations.
45
Where does SO2 occur at a coal mine
SPON COM / Heatings in coal containing SULPHUR DIESEL EXHAUST EMISSIONS BURNING RUBBER
46
Is SO2 a flammable gas
It is INCOMBUSTIBLE and NON FLAMMABLE
47
Nitrogen Dioxide 48. State the chemical and physical properties of NO2:
Reddish brown colour, an acrid smell and acid taste. SG of1.6. NO2 Although incombustible and non-flammable, it Will SUPPORT COMBUSTION
48
State the maximum exposure limit concentration of NO2
STEL is 5ppm
49
How does Nitrogen dioxide occur at a coal mine.
Component of diesel exhausts, shotfiring
50
Although NO2 is not flammable, | What does it support
Combustion
51
State the physiological effects of NO2
Extremely poisonous. Coughing. Seriously irritates the lungs and respiratory passages. Symptoms of acute bronchopneumonia. Death.
52
Gas Sensors/Detectors Type of gas sensors: Oxygen O-GE Carbon monoxide-3- M-EGIT Carbon dioxide -2- D-IGT Methane-2- M-ITG cc Nitrogen -GC Hydrogen Sulphide H-EGT Sulphur dioxide S-EGT Hydrogen - GC Nitrogen dioxide N-EGT
Oxygen - GC. EC Carbon monoxide-EC GC IR TUBE ``` Carbon dioxide- IR, GC, Tube Methane- IR, Thermal, GC, CC Nitrogen- GC Hydrogen Sulphide- EC, GC, Tube Sulphur dioxide- EC, GC, Tube ``` Hydrogen. - GC Nitrogen dioxide. - EC, GC, Tube
53
How often does the gas detector have to be fully calibrated to NATA standard
Every 6 Months
54
How often does the gas detector have to be tested using known levels of gases
Before each shift
55
Electronic multi gas detectors can be cleaned using what
Damp soft cloth / bristle brush
56
What could high [condensation] humidity do to an Oxygen sensor reading
Cause sensor to fail
57
Why is it not advisable to breath over sensors
Moisture from exhaled breath can poison O2 sensor
58
State 2 advantages of an infrared methane sensor has over a catalytic combustion methane sensor
1. NOT DEPENDANT of Oxygen | 2. NOT CROSS SENSITIVE
59
What should the oxygen sensor of a handheld gas detector read
20.95
60
What is the MINIMUM oxygen level required for correct operation of a catalytic combustion sensor ( CC )
10%
61
What is the normal MEASURING RANGE range for a Wheatstone Bridge or Pellistor (catalytic oxidation principle) type methanometer
0% to 5% of LEL
62
Name 2 gases that could cause “cross Interference” on CO sensor
1. H2S | 2. SO2
63
What does T90 refer to when using a personal gas detector
The time taken to reach 90% of the test gas concentration of no more than 30secs
64
What gas detector is used to detect “Volatile Organic Compounds” VOC’s
PID (Photoionization Detector)
65
What does intrinsic safety mean when using a gas detector
One which is intended for use in a potentially explosive atmosphere
66
When should you use a pump style gas detector
Remote sampling | Confined Space
67
What are the effects of air velocities on gas detectors
Displaces gases and does not give true reading
68
Miscellaneous Where could Methane be found on surface mine Name 3 areas
1: Seam Gas - Blasting 2: Sewage - Drill Holes 3: Produced NATURALLY during PEAT to LIGNITE transformation
69
Where could Nitrogen Dioxide be found on a surface mine
Blast flume, | Diesel exhaust
70
Areas where Sulphur dioxide could be found
When sulphur is in coal/spon com
71
What are the 5 factors that must occur simultaneously for an explosion to occur
1. Oxygen 2. Fuel 3 .Heat 4. Suspension 5. Confinement
72
Where can carbon monoxide can be found on the surface. Name 2
1. Heatings -Fires - Spon Com | 2. Diesel exhaust - Explosions
73
What 2 gases can be found in confined spaces at CHPP
1. - Hydrogen Sulphide. H2S 2. - Carbon Monoxide. CO 3. - Oxygen. O2 4. - MIBC (Floculant? )
74
What gases can be found when an inversion layer occurs
All seam gases
75
What gases can be found when a product cylinder leaks
Whatever is inside the cylinder etc. (LPG, Acetylene)
76
What risk control method is used at your mine when responding to the detection of flammable & toxic gases
TARP (Trigger Action Response Plan)
77
When coal heats gases appear at characteristic temps, Name 6
1. Carbon dioxide CO 2. Carbon monoxide CO2 3. Methane CH4 4. Hydrogen H2 5. Ethane 6. Hydrocarbons
78
Convert 400PPM to %
0.04%
79
What must occur for a person working more than the stated hours for applicable long term exposure limits
The TWA standard will need to be adjusted to the Recognised Standard
80
What is the applicable long term exposure limit concentration for various atmospheric contaminants
Define long term exposure for hours in a day and hours in a week. 8hr / 40hr week
81
What is the maximum general body concentration of CARBON DIOXIDE a person can be exposed if a continual personal monitoring method is used
TWA- 1.25% = 12500 ppm STEL- 3% = 30000 ppm
82
What should be recorded when taking gas readings in the excavations. Name 6
1. Person name 2. Gas type 3. Location 4. Time 5. Date 6. Weather conditions
83
``` Abbreviations CNS- Central Nervous System SG- Specific Gravity COT- Colourless, Odourless, Tasteless EC- Electrochemical PID- Photoionization Detector GC- Gas Chromatograph IR- Infrared TWA- Time Weighted Average STEL- Short Term Exposure Limit LEL- Lower Explosive Limit UEL- Upper Explosive Limit NF- Non Flammable ```
``` Abbreviations CNS- Central Nervous System SG- Specific Gravity COT- Colourless, Odourless, Tasteless EC- Electrochemical PID- Photoionization Detector GC- Gas Chromatograph IR- Infrared TWA- Time Weighted Average STEL- Short Term Exposure Limit LEL- Lower Explosive Limit UEL- Upper Explosive Limit NF- Non Flammable ```

Coal Mine Gases (1 decks)

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