Mine Gases section 1 Flashcards
name 8 gases relevant to coal mining
hydrogenH2.07 methaneCH4 .55 carbonmonoxideCO .97 oxygen O2 1.11 hydrogen sulphideH2S 1.18 carbondioxideCO21.52 nitrogendioxideNO21.6 sulphurdioxideSO22.2
explain the effects on a person of oxygen concentrations @ 16 - 14%, 14 - 10% and 10 - 6%
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
what is the minimum concentration of oxygen a cmw can be exposed to?
19.5%
what are the gas constituents of normal air and their percentages?
nitrogen 78.08% oxygen 20.95% argon/inert .93% water vapour/carbon dioxide .04%
at what percentages of oxygen do a)flammable liquids cease burning b)all flaming combustion stops c) all combustion ceases
a) 17% b) 10 -12% c) 2%
what effect does an oxygen enriched atmosphere have on the UPPER FLAMMABLE Limit of FG?
expands the flammable limits of a FG
what 2 gases are released when blasting with explosives?
Nitrogen dioxide N02 Carbon monoxide CO
how can you identify if Nitrogen Dioxide has been released during a blast?
a reddish brown colour in the gas fume
what is the TWA, Short Term Exposure Limit STEL & Immediate Danger to Health or Life IDHL for Nitrogen dioxide NO2
TWA 3ppm (0.0003 %)
STEL 5ppm
IDHL 20ppm
Name 4 signs or symptoms of exposure to NO2
feeling ill, coughing violently, symptoms of bronchitis/pneumonia, cessation of life
a cmw must not be exposed to an atmosphere at the mine containing a general body concentration 0f CO2 exceeding?
TWA - 1.25% = 12,500 ppm
STEL - 3% = 30,000 ppm
explain what effects occur to a person at the following concentrations of CO2?
2% - 5% increased in lung ventilation
4.5 - 5% - anxiety, panic, irritability
10% - toxic, depresses CNS (Central Nervous
System) violent panting, exhaustion,
headache
carbon dioxide CO2 is described as a “hot gas” due to its low thermal conductivity, explain
due to its insulating properties it gives a feeling of warmth
carbon dioxide CO2 a) how is it produced and b) where is it found on a mine site?
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
describe the physical and chemical properties of CO2
CO2 - specific gravity SG 1.2 non flammable NF colourless, slight pungent odour, soda water taste
describe the physiological effects of carbon dioxide CO2 at low and high concentrations
low - stimulates central nervous system CNS
high - depresses CNS
is carbon dioxide CO2 a flammable gas? if so, at what concentration?
it is an inert gas, non-flammable NF
state the long term exposure limits for carbon monoxide CO, hydrogen sulphide H2S, nitrogen dioxide NO2, sulphur dioxide SO2
CO - 30ppm, H2S - 10ppm, NO2 - 3ppm, SO2 - 2 ppm
how is the human body poisoned by carbon monoxide CO?
CO is absorbed 300x more readily by the body than oxygen O2 and prevents O2 from binding to the red blood cell
in regards to carbon monoxide poisoning, what is meant by the term blood saturation?
blood becomes soaked with CO that prevents the blood from taking on anymore O2 or CO
carbon monoxide poisoning is said to have a cumulative effect. what is meant by cumulative effect?
multiple small exposures to CO can build up in a person making them more susceptible to its effect
how is carbon monoxide CO produced in coal mines? give 4 examples
oxidisation of coal, fires, heating, explosions and diesel engine exhaust
is carbon monoxide CO an explosive gas? if so, at what concentration?
yes, it is explosive
explosive range is 12.5 % - 74 %
name 6 signs and symptoms that would be associated with carbon monoxide CO poisoning
1) impairment of visual threshold 2) nausea/headache 3) rosy/flushed face 4) becoming silent 5) unsteady gait 6) heavy feeling in legs
