Mine Gases

• Constituents of different kinds of gases in atmosphere by weight or by volume:-

• Air is required in mines for four important reasons namely:-

1. To supply oxygen for breathing.
2. To remove heat from U/G environment.
3. To dilute the presence of dust and various unwanted gases.
4. To remove dust.

• When referring to noxious & poisonous gases met in the mines,the commonly used names are as follows:-

1. BLACK DAMP:-  It is the mechanical mixture of CO₂ and excess N and extinctive gases. It is also known as Choke Damp or Stythe.
2. FIRE DAMP:-  It is a synonymous mixture of CH₄ and air. It is referring to the mechanical mixture of gases chiefly inflammable given off naturally from the coal and consisting most part of CH₄ .
3. WHITE DAMP:-  It is synonymous with CO.
4. STINK DAMP:-  It is sulphurated hydrogen(H₂S).
5. AFTER DAMP:- This is the mechanical mixture of gases existing in a mine after explosion of firedamp and coal dust. Its composition is extremely variable & usually include CO,CO₂,N,N₂S,SO₂ with very small percentage of oxygen.

• Common gases in a mine:-

OXYGEN(O₂)

 NITROGEN(N₂)

CARBON DI-OXIDE(CO₂)

 CARBON MONO-OXIDE(CO)

METHANE(CH₄)