Mine Gases Flashcards

Flashcards about mine gases

Specific gravity of a gas

Indicates how quickly a gas will diffuse and how easily it can be dispersed by ventilation.

Usual mine conditions

A rapid mechanical mixing of gases with air due to ventilating air currents and convection currents produced by temperature differences.

Light gases

Diffuse rapidly and are fairly easy to disperse.

Heavier gases

Do not diffuse rapidly, so they're more difficult to disperse.

An increase in temperature

Makes a gas diffuse more rapidly.

A decrease in temperature

Slows down the rate of diffusion.

An increase in pressure

Slows down the rate of diffusion.

A decrease in pressure

Speeds up the rate of diffusion.

In order for a flammable gas to explode, there must be:

Enough of the gas in the air, enough oxygen, and a source of ignition.

What is the explosive range?

The range of concentrations within which a gas will explode.

What is solubility?

The ability of a gas to be dissolved in water.

Why is it important for you to know about the solubility of certain gases in water?

Gases dissolved in water can be liberated in large quantities when mine rescue teams disturb the water.

Why should you know about the characteristic color, odor, and taste of gases you may encounter?

The characteristic color and, if the team is barefaced, odor or taste of a gas may be the first clue a rescue team has that the gas is present in the mine atmosphere.

How does an asphyxiating gas produce an oxygen-deficient atmosphere?

By displacing oxygen.

How do you protect yourself in an oxygen-deficient atmosphere?

Wear an SCBA, which supplies you with oxygen.

Other toxic gases

harm the skin or can be absorbed by the skin.

The specific gravity (or relative weight) of a gas is its weight in relation to

an equal amount of normal air under the same temperature and pressure.

It's important for you to know the explosive ranges of gases you encounter and the amount of oxygen necessary for an explosion so you

Immediately know when you encounter a potentially explosive atmosphere.

The degree to which a toxic gas will affect you depends on three factors:

how concentrated the gas is, how toxic the gas is, and how long you're exposed to the gas.

TLVS denote

Average concentrations of gases to which workers are permitted to be exposed over an 8-hour daily period.

Pools of water can

release water-soluble gases into the air when they are stirred up.

Hydrogen sulfide

has a distinctive "rotten egg" odor.

Of course, you can't rely on only your senses to positively identify a gas. Only ____ can do that.

detectors and chemical analysis