Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Mine Gases > Mine Gases section 1 > Flashcards

Mine Gases section 1 Flashcards

1
Q

name 8 gases relevant to coal mining

A

hydrogenH2.07 methaneCH4 .55 carbonmonoxideCO .97 oxygen O2 1.11 hydrogen sulphideH2S 1.18 carbondioxideCO21.52 nitrogendioxideNO21.6 sulphurdioxideSO22.2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

explain the effects on a person of oxygen concentrations @ 16 - 14%, 14 - 10% and 10 - 6%

A

slight nausea, increase in pulse/breathing rate, nigh/colour vision & judgement affected, abnormal fatigue on exertion : PJ, AFOE : nausea&vomiting, inability to move or cry out, loss of conciousness may occur

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what is the minimum concentration of oxygen a cmw can be exposed to?

A

19.5%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what are the gas constituents of normal air and their percentages?

A

nitrogen 78.08% oxygen 20.95% argon/inert .93% water vapour/carbon dioxide .04%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

at what percentages of oxygen do a)flammable liquids cease burning b)all flaming combustion stops c) all combustion ceases

A

a) 17% b) 10 -12% c) 2%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what effect does an oxygen enriched atmosphere have on the UPPER FLAMMABLE Limit of FG?

A

expands the flammable limits of a FG

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what 2 gases are released when blasting with explosives?

A

Nitrogen dioxide N02 Carbon monoxide CO

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

how can you identify if Nitrogen Dioxide has been released during a blast?

A

a reddish brown colour in the gas fume

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what is the TWA, Short Term Exposure Limit STEL & Immediate Danger to Health or Life IDHL for Nitrogen dioxide NO2

A

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

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Name 4 signs or symptoms of exposure to NO2

A

feeling ill, coughing violently, symptoms of bronchitis/pneumonia, cessation of life

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

a cmw must not be exposed to an atmosphere at the mine containing a general body concentration 0f CO2 exceeding?

A

TWA - 1.25% = 12,500 ppm
STEL - 3% = 30,000 ppm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

explain what effects occur to a person at the following concentrations of CO2?

A

2% - 50% increased in lung ventilation
4.5 - 5% - anxiety, panic, irritability
10% - toxic, depresses CNS (Central Nervous
System) violent panting, exhaustion,
headache

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

carbon dioxide CO2 is described as a “hot gas” due to its low thermal conductivity, explain

A

due to its insulating properties it gives a feeling of warmth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

carbon dioxide CO2 a) how is it produced and b) where is it found on a mine site?

A

a) oxidisation of coal & carbon based materials, exhaust fumes from combustion engines, blasting operations and fires
b) diesel exhaust, blast fume, spon com, inert firefighting gases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

describe the physical and chemical properties of CO2

A

CO2 - specific gravity SG 1.2 non flammable NF colourless, slight pungent odour, soda water taste

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

describe the physiological effects of carbon dioxide CO2 at low and high concentrations

A

low - stimulates central nervous system CNS
high - depresses CNS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

is carbon dioxide CO2 a flammable gas? if so, at what concentration?

A

it is an inert gas, non-flammable NF

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

state the long term exposure limits for carbon monoxide CO, hydrogen sulphide H2S, nitrogen dioxide NO2, sulphur dioxide SO2

A

CO - 30ppm, H2S - 10ppm, NO2 - 3ppm, SO2 - 2 ppm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

how is the human body poisoned by carbon monoxide CO?

A

CO is absorbed 300x more readily by the body than oxygen O2 and prevents O2 from binding to the red blood cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

in regards to carbon monoxide poisoning, what is meant by the term blood saturation?

A

blood becomes soaked with CO that prevents the blood from taking on anymore O2 or CO

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

carbon monoxide poisoning is said to have a cumulative effect. what is meant by cumulative effect?

A

multiple small exposures to CO can build up in a person making them more susceptible to its effect

22
Q

how is carbon monoxide CO produced in coal mines? give 4 examples

A

oxidisation of coal, fires, heating, explosions and diesel engine exhaust

23
Q

is carbon monoxide CO an explosive gas? if so, at what concentration?

A

yes, it is explosive
explosive range is 12.5 % - 74 %

24
Q

name 6 signs and symptoms that would be associated with carbon monoxide CO poisoning

A

1) impairment of visual threshold 2) nausea/headache 3) rosy/flushed face 4) becoming silent 5) unsteady gait 6) heavy feeling in legs

25
Q

state the chemical and physical properties of carbon monoxide

A

CO - SG 0.97 flammable, highly poisonous
COT - Colourless/Odourless/Tasteless

26
Q

what is the ignition temperature of methane CH4?

A

537’C Australian Standard

27
Q

what is the minimum concentration of oxygen O ( at normal atmosphere ) for a methane CH4 explosion to occur?

A

12.2 %

28
Q

is methane CH4 poisonous?

A

non-toxic, will not support life

29
Q

state the chemical and physical properties of methane CH4

A

CH4 - SG 0.55
Flammable, COT

30
Q

what is the exposive range of methane CH4 in normal air and ambient temperature?

A

5 % - 15 %

31
Q

what is the most easily ignited % of methane CH4 from a heated surface in a mixture of air & CH4?

A

5 % - 6 %

32
Q

explain the term “Lag of Ignition”

A

time period that a flammable gas mixture is in contact with a heat source prior to an ignition taking place. it is dependant on gas concentration and temperature of heat source

33
Q

what is the Lag of Ignition for methane CH4 at 5% - 6%?

A

2 seconds

34
Q

explain how methane CH4 is produced and found on a mine site?

A

a) produced naturally during peat to lignite transformation
b) found in almost al coal seams & some coal bearing strata

35
Q

what effect can the presence of coal dust suspended in the atmosphere have on the LEL of methane CH4?

A

can lower the LEL to 5% -0%

36
Q

what percentage of methane CH4 is recognised as the most explosive in air?

A

9.5%

37
Q

what effects does the increase of ambient temperature have on a flammable gas/air mixture?

A

increases the upper explosive limit UEL and lowers the lower explosive limit LEL

38
Q

state where hydrogen sulphide H2S could be found on the mine?

A

stagnant water, seam gas, spon com in coal containing pyrites

39
Q

what is the concentration of hydrogen sulphide H2S that causes dizziness, excitement, nausea, dryness & pain in nose/throat/chest, coughing and irritation of mucus membranes?

A

250 - 600 ppm

40
Q

explain the chemical and physical properties of hydrogen sulphide H2S?

A

H2S SG 1.18
Flammable, colourless, rotten egg smell, sweetish taste

41
Q

state the physiological effects hydrogen sulphide H2S has on a person

A

toxic, irritates eyes,throat and respiratory tract, narcotic effect on the central nervous system CNS

42
Q

is hydrogen sulphide H2S a flammable gas? if so, at what percentage in air?

A

4.3% - 45% flammable limit
auto ignition temp of 260’C

43
Q

state the chemical and physical properties of sulphur dioxide

A

SO2 - SG 2.2 N-F
colourless, suffocating pungent odour, almost intolerable acidic taste

44
Q

state the physiological effects sulphur dioxide SO2 has on a person

A

extremely poisonous, irritates lungs and respiratory passage, intolerable to breathe at certain concentrations

45
Q

where does sulphur dioxide occur on the mine site?

A

spon com in coal containing sulphur, diesel exhaust emissions, burning rubber

46
Q

is sulphur dioxide SO2 a flammable gas? if so, at what percentage?

A

no, it is incombustible and non-flammable

47
Q

state the chemical and physical properties of nitrogen dioxide

A

NO2 - SG 1.6 N-F (will support combustion)
reddish brown colour
acrid smell, acid taste

48
Q

state the maximum exposure limit for nitrogen dioxide NO2

A

short term exposure limit STEL 5 ppm

49
Q

how does nitrogen dioxide occur at the mine?

A

shotfiring
component of diesel exhaust

50
Q

although nitrogen dioxide is N-F what does it support?

A

combustion

51
Q

state the physiological effects nitrogen dioxide NO2 has on the body

A

extremely poisonous
coughing
seriously irritates lungs, eyes, respiratory tract
symptoms of acute bronchopneumonia
cessation of life

Mine Gases (3 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions