| Methane |
| Q: | Where is Methane most likely to be found in a mine? |
| A: | Near the roof, as it is lighter than air. |
| |
| Q: | What is a flammable mixture of methane and air which can either burn or explode when ignited called?
|
| A: | Firedamp
|
| |
| Q: | What is the ignition temperature of methane?
|
| A: | 1100-1380o F.
|
| |
| Q: | What instruments are most often used in detecting methane?
|
| A: | The flame safety lamp and methane detectors.
|
| |
| Q: | What is the least percentage of methane that can be detected with a flame safety lamp?
|
| A: | About one percent (1%).
|
| |
| Q: | What effect does the presence of methane have upon the explosibility of coal dust?
|
| A: | The coal dust is more easily ignited and the force of the explosion is greater.
|
| |
| Q: | What effect does coal dust in the air have upon the explosibility of methane?
|
| A: | The lower explosive limit is decreased.
|
| |
| Q: | What dangerous gas is most likely to be encountered above a pillar fall?
|
| A: | Methane.
|
| |
| Q: | What effect does the presence of methane have upon the explosibility of coal dust?
|
| A: | The coal dust is more easily ignited and the force of the explosion is greater.
|
| |
| Q: | What effect does coal dust in the air have upon the explosibility of methane?
|
| A: | The lower explosive limit is decreased.
|
| |
| Q: | What dangerous gas is most likely to be encountered above a pillar fall?
|
| A: | Methane.
|
| |
| Q: | Why will methane accumulate in an inadequately ventilated place?
|
| A: | It is lighter than air and will rise and stratify if not properly diffused.
|
| |
| Q: | What is the principle combustible gas usually found in coal mines?
|
| A: | Methane.
|
| |
| Q: | Is methane (CH4) poisonous?
|
| A: | No
|
| |
| Q: | What is the color of methane?
|
| A: | Methane is colorless.
|
| |
| Q: | Which is the heaviest, one cubic foot of methane or one cubic foot of air?
|
| A: | One cubic foot of air.
|
| |
| Q: | What gas is found near the roof and cavities on falls?
|
| A: | Methane (CH4).
|
| |
|
|
| |
| Q: | What gas is odorless, tasteless, non-toxic, colorless and explosive in the concentration of 5%-15%?
|
| A: | Methane
|
| |
| Q: | What is the source of methane in coal mines?
|
| A: | It is liberated from coal and adjoining strata.
|
| |
| Q: | What is the specific gravity of methane?
|
| A: | 0.555.
|
| |
| Q: | Where is methane usually found in mines?
|
| A: | Along the roof, to the rises, in the vicinity of working faces, in dead ends and above falls.
|
| |
| Q: | Is methane an explosive by itself?
|
| A: | No. Oxygen is required to support combustion.
|
| |
| Q: | Why can there be no explosion when the percentage of methane is greater than fifteen percent (15%)?
|
| A: | Because the amount of oxygen present is insufficient for rapid combustion to occur.
|
| |
| Q: | How can methane gas be detected in a coal mine?
|
| A: | Chemical analysis, flame safety lamp and methane detectors.
|
| |
| Q: | What is the explosive range of methane?
|
| A: | Five to fifteen percent.
|
| |
| Q: | What is the percentage of methane required for maximum explosive violence?
|
| A: | Ten percent (10%).
|
| |
|
| Carbon Monoxide |
| Q: | What percent of carbon monoxide can cause death in less than one hour?
|
| A: | 0.4 percent or more.
|
| |
| Q: | What is the ignition temperature of Carbon monoxide?
|
| A: | 1100 degrees F.
|
| |
| Q: | Why are small quantities of carbon monoxide injurious?
|
| A: | Because it is not easily eliminated and it accumulates in the blood.
|
| |
| Q: | What is the specific gravity of carbon monoxide?
|
| A: | 0.967.
|
| |
| Q: | What is carbon monoxide (CO)?
|
| A: | It is a colorless, odorless, tasteless, combustible, and poisonous gas.
|
| |
| Q: | How can carbon monoxide be detected?
|
| A: | By carbon monoxide detectors, and by analysis.
|
| |
| Q: | Workers should not be employed for a period of 8 hours where the carbon monoxide content exceeds what?
|
| A: | 50 PPM (0.005%)
|
| |
| Q: | What percentage of carbon monoxide might produce symptoms of poisoning if breathed indefinitely?
|
| A: | 0.01%.
|
| |
| Q: | What is the source of carbon monoxide?
|
| A: | It is the product of incomplete combustion (combustion with an insufficiency of oxygen).
|
| |
| Q: | When is carbon monoxide most likely to be found in mines?
|
| A: | When there is a mine fire or after an explosion.
|
| |
| Q: | What does the presence of CO in a sealed mine area indicate?
|
| A: | A fire.
|
| |
| Q: | What percentage of blood saturation by Carbon monoxide (CO) will cause death?
|
| A: | 70% -80%.
|
| |
| Q: | The explosive range of carbon monoxide is what?
|
| A: | 12.5-74 percent.
|
| |
| Q: | What percentage of carbon monoxide will produce slight symptoms in several hours?
|
| A: | 200 PPM (.02%).
|
| |
| Q: | What percentage of carbon monoxide will produce discomfort in two or three hours?
|
| A: | 400 PPM (.04%).
|
| |
| Q: | What percentage of carbon monoxide will produce a tendency to stagger in one and one-half (12) hours?
|
| A: | 1200 PPM (0.12%).
|
| |
| Q: | What percentage of carbon monoxide will produce symptoms of unconsciousness in thirty (30) minutes?
|
| A: | 2000-2500 PPM (.20%-.25%).
|
| |
| Q: | How much greater affinity does hemoglobin have for carbon monoxide than for oxygen?
|
| A: | About three hundred (300) times.
|
| |
| Q: | What is the principal poisonous gas produced by explosions?
|
| A: | Carbon monoxide.
|
| |
| Q: | What effect does carbon monoxide have on life?
|
| A: | It is extremely poisonous.
|
| |
| Q: | How does carbon monoxide cause injury to life?
|
| A: | By combining with the hemoglobin of the blood and excluding oxygen.
|
| |
|
| Oxides of Nitrogen |
| Q: | How are oxides of Nitrogen formed?
|
| A: | From the use of explosives in mines.
|
| |
| Q: | How do oxides of nitrogen cause death?
|
| A: | Causes fluid to accumulate in lungs resulting in asphyxia.
|
| |
| Q: | How are results from analysis of oxides of nitrogen reported?
|
| A: | In terms of nitrogen dioxide.
|
| |
| Q: | List the threshold limit value for oxides of nitrogen.
|
| A: | 5 ppm.
|
| |
|
| Hydrogen |
| Q: | What are the sources of Hydrogen in a mine?
|
| A: | Charging batteries, mine fires, and explosions.
|
| |
| Q: | Hydrogen is always present after what type of explosion?
|
| A: | Coal dust explosions.
|
| |
| Q: | Is hydrogen explosive?
|
| A: | Yes.
|
| |
| Q: | What is the specific gravity of hydrogen?
|
| A: | It is the lightest of all gases with a specific gravity of 0.0695
|
| |
| Q: | Name the gas which is generated from a storage battery.
|
| A: | Hydrogen (H2).
|
| |
| Q: | What is the explosive range of hydrogen?
|
| A: | 4.1 to 74 percent.
|
| |
| Q: | How is hydrogen detected?
|
| A: | By chemical analysis.
|
| |
| Q: | Is hydrogen flammable?
|
| A: | Yes.
|
| |
|
| Miscellaneous |
| Q: | Write down the chemical symbols of methane and hydrogen sulfide.
|
| A: | CH4 and H2S
|
| |
| Q: | Name the non-explosive gases found in coal mines.
|
| A: | Carbon dioxide (CO2) and Nitrogen (N2)
|
| |
| Q: | Name the explosive gases found in bituminous coal mines in Pennsylvania.
|
| A: | Methane (CH4), Carbon Monoxide (CO), and Hydrogen Sulfide (H2S).
|
| |
| Q: | What is TLV?
|
| A: | Threshold limit value.
|
| |
| Q: | Convert 0.01 percent of carbon monoxide to ppm.
|
| A: | 100 ppm.
|
| |
| Q: | What is noxious gas?
|
| A: | Any gas in the air which is harmful to life when inhaled.
|
| |
| Q: | What is the percentage of oxygen below which no explosion of a methane air-mixture can occur?
|
| A: | Twelve percent (12%).
|
| |
| Q: | What effect does an atmosphere with a reduced oxygen content have upon the explosibility of methane?
|
| A: | A greater percentage of methane is necessary to start an explosion in an atmosphere which contains less than the normal percentage of oxygen.
|
| |
|
|
|
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|
| Oxygen |
| Q: | What percentage of the earth's atmosphere is oxygen?
|
| A: | 20.94 percent oxygen.
|
| |
| Q: | A sealed area of a coal mine after a period of time will be found to have the absence of what?
|
| A: | Oxygen.
|
| |
| Q: | Can there be a mine fire or an explosion without the presence of oxygen?
|
| A: | No
|
| |
| Q: | Is Oxygen flammable or explosive?
|
| A: | No, oxygen alone will not burn or explode, it merely supports combustion. However, oxygen enriched atmospheres,
along with the presence of the ignition of a flammable material will produce extremely rapid burning and in some cases flash, which perpetuates the myth
that oxygen is flammable and explosive.
|
| |
| Q: | Mine air should not contain less than what percentage of oxygen?
|
| A: | 19.5%.
|
| |
| Q: | How does the body receive oxygen?
|
| A: | Through breathing, the oxygen is taken up by the hemoglobin of the blood and carried to all parts of the body.
|
| |
| Q: | What supports the chemical reaction that produces fires and explosions?
|
| A: | Oxygen.
|
| |
| Q: | What percent oxygen can a person most easily work in?
|
| A: | 20.9%
|
| |
| Q: | What percent oxygen will a person breathe faster and deeper while at work?
|
| A: | 17 percent.
|
| |
| Q: | A flame safety lamp will go out when the oxygen percentage is below what?
|
| A: | 16 percent.
|
| |
| Q: | What element in the air is essential for life?
|
| A: | Oxygen.
|
| |
| Q: | How does the body receive oxygen?
|
| A: | By breathing, oxygen is absorbed by the blood and carried to the cells of the body.
|
| |
| Q: | When is the oxygen (O2) level in air considered to be dangerous?
|
| A: | When the Oxygen (O2) level falls below 16%.
|
| |
|
| Nitrogen |
| Q: | What percent of the earth's atmosphere is nitrogen?
|
| A: | 78.09 % Nitrogen
|
| |
| Q: | What is the threshold limit value of nitrogen?
|
| A: | 81%.
|
| |
| Q: | What is nitrogen?
|
| A: | It is a tasteless, odorless and colorless gas which will neither support life nor combustion.
|
| |
| Q: | Is nitrogen combustible?
|
| A: | No.
|
| |
| Q: | What effect does nitrogen have towards propagating an explosion?
|
| A: | None
|
| |
| Q: | What effect does nitrogen have upon life?
|
| A: | It has no effect. except when it depletes oxygen to the extent that there is a deficiency of oxygen.
|
| |
| Q: | Does nitrogen have an ignition temperature?
|
| A: | No, nitrogen will not explode.
|
| |
|
| Diffusion of Gases |
| Q: | Once two or more gases mix uniformly will they separate or come apart?
|
| A: | No
|
| |
| Q: | Define the term diffusion of gases.
|
| A: | Diffusion is a phenomenon by which gases mix by natural forces.
|
| |
| Q: | What is the law of diffusion?
|
| A: | The rate of diffusion varies inversely as the square root of specific gravity.
|
| |
| Q: | What is stratification?
|
| A: | When gases do not diffuse completely, layers of gas stratify horizontally.
|
| |
| Q: | What type of atmosphere is easy for the detection of a gas a diffused one or a stratified one?
|
| A: | A stratified one.
|
| |
|
| Carbon Dioxide |
| Q: | Is carbon dioxide combustible?
|
| A: | No.
|
| |
| Q: | What is the specific gravity of carbon dioxide?
|
| A: | 1.529
|
| |
| Q: | Where might concentrated accumulations of carbon dioxide ordinarily be found?
|
| A: | Near the floor, in inadequately ventilated places.
|
| |
| Q: | What effect does carbon dioxide have upon life?
|
| A: | Respiration is increased as concentration of carbon dioxide increases.
|
| |
| Q: | How is carbon dioxide detected?
|
| A: | Usually by chemical analysis.
|
| |
| Q: | What is carbon dioxide (CO2)?
|
| A: | Carbon dioxide is a colorless and odorless gas formed by the chemical combination of carbon and oxygen.
|
| |
| Q: | How is carbon dioxide formed in a mine?
|
| A: | By combustion, by breathing of miners and animals, by decay of vegetable and animal matter, by the oxidation of coal and by chemical action of acid water on carbonates.
|
| |
| Q: | What is a product of complete combustion?
|
| A: | Carbon dioxide.
|
| |
| Q: | Where might concentrated accumulations of carbon dioxide ordinarily be found?
|
| A: | Near the floor, in inadequately ventilated places.
|
| |
| Q: | What effect does carbon dioxide have upon life?
|
| A: | Respiration is increased as concentration of carbon dioxide increases.
|
| |
| Q: | How is carbon dioxide detected?
|
| A: | Usually by chemical analysis
|
| |
| Q: | What is carbon dioxide (CO2)?
|
| A: | Carbon dioxide is a colorless and odorless gas formed by the chemical combination of carbon and oxygen.
|
| |
| Q: | How is carbon dioxide formed in a mine?
|
| A: | By combustion, by breathing of miners and animals, by decay of vegetable and animal matter, by the oxidation of coal and by chemical action of acid water on carbonates.
|
| |
| Q: | What is a product of complete combustion?
|
| A: | Carbon dioxide
|
| |
| Q: | What is the chemical symbol of carbon dioxide?
|
| A: | CO2
|
| |
|
| Sulfur Dioxide |
| Q: | How is sulfur dioxide formed in a mine?
|
| A: | By burning coal containing pyrites
|
| |
| Q: | What is the specific gravity of sulfur dioxide?
|
| A: | 2.263.
|
| |
| Q: | What is the particular danger of sulfur dioxide?
|
| A: | It is extremely poisonous even in small amounts
|
| |
| Q: | How is sulfur dioxide detected?
|
| A: | By the sense of smell and its effect on the air passages.
|
| |
| Q: | What is the first effect on a person exposed to sulfur dioxide?
|
| A: | It is extremely irritating and suffocating and is intolerable to breathe.
|
| |
| Q: | Is sulfur dioxide combustible?
|
| A: | No, it is incombustible.
|
| |
| Q: | Is sulfur dioxide soluble in water?
|
| A: | Yes.
|
| |
|
| Hydrogen Sulfide |
| Q: | What are the properties of hydrogen sulfide?
|
| A: | Poisonous and colorless with an odor like rotten eggs
|
| |
| Q: | What mine gas can be detected by its odor?
|
| A: | Hydrogen sulfide
|
| |
| Q: | What is the origin of hydrogen sulfide?
|
| A: | It is liberated by burning explosives containing sulfur such as black powder or dynamite.
|
| |
| Q: | How can hydrogen sulfide be detected other than by sense of smell?
|
| A: | By the hydrogen sulfide detector or by paper dipped in acetate of lead. which will turn black immediately on exposure to hydrogen sulfide.
|
| |
| Q: | What distinctive odor does hydrogen sulfide gas smell like?
|
| A: | Smells like rotten eggs.
|
| |
| Q: | What is the specific gravity of hydrogen sulfide?
|
| A: | 1.191
|
| |
| Q: | What is the explosive range of Hydrogen Sulfide?
|
| A: | 4.3% to 45%.
|
| |
| Q: | Is hydrogen sulfide poisonous?
|
| A: | Yes, it is extremely poisonous even in small amounts.
|
| |
| Q: | What is the immediate effect of hydrogen sulfide on a person?
|
| A: | It is extremely irritating to the eyes.
|
| |
| Q: | What is the threshold limit value of hydrogen sulfide?
|
| A: | 10 PPM.
|
| |
| Q: | Among methane, carbon monoxide, and hydrogen sulfide, which one has the lowest ignition temperature?
|
| A: | Hydrogen Sulfide (700°F).
|
| |
|
| Mine Damps |
| Q: | What is meant by the term "black damp"?
|
| A: | An atmosphere deficient in oxygen.
|
| |
| Q: | What is the effect of black damp' on flame safety lamp?
|
| A: | The flame of a safety lamp is dimmed or extinguished depending on concentration of gases present.
|
| |
| Q: | What is the most simple and safe test for the presence of black damp?
|
| A: | A flame safety lamp.
|
| |
| Q: | Stink damp refers to which gas?
|
| A: | Hydrogen sulfide
|
| |
| Q: | White damp refers to which gas?
|
| A: | Carbon monoxide.
|
