What happens when coal seams are exposed to air?

Coal seams are the source as well as the reservoir for all gases. All coal seams begin to oxidize when exposed to ventilation air in a mine and produce some carbon monoxide and hydrogen sulfide. Sulfur dioxide and nitrogen oxides are produced by diesel equipment in coal mines.

What is a coal seam made of?

Definition of coal seam : a bed of coal usually thick enough to be profitably mined.

Why does coal occur in seams?

One well known source of fires is mining breaking into a high pressure cavity of methane gas which on release can generate a spark of static electricity to ignite the gas and start a coal explosion and fire. The same gas static is well known in ships and care has to be taken to ensure no such static sparking can occur.

What is coal made of chemically?

Because it originally formed from plants, coal contains mostly carbon, hydrogen, oxygen, and nitrogen. Coal helped create the carbon-based branch of chemistry we call “organic chemistry.” When coal is heated in the absence of air, its complex mixture breaks down into simpler forms.

How do coal seams work?

Coal seams are formed from dead and decaying organic matter. Generally, this matter came from ancient peat bogs that died and fell into shallow, stagnant waters. As this material decayed, it became peat over time. This compression and heating slowly turned the soft peat into harder lignite coal.

When were coal seams formed?

about 300 million years ago
The conditions that would eventually create coal began to develop about 300 million years ago, during the Carboniferous period. During this time, the Earth was covered in wide, shallow seas and dense forests.

Why do coal seam fires last for so long?

“Unlike timber, coal when it gets hot has massive thermal mass which is very hard to extinguish. Coal, and particularly brown coal, is very reactive to oxygen, and will generate CO2 and that creates heat. As the coal gets hotter it will eventually get to flame temperature and that coal will burn.”

Where are coal seams found?

Coal seams exist on every continent. The largest coal reserves are in the United States, Russia, China, Australia, and India. In the United States, coal is mined in 25 states and three major regions.

How coal is formed step by step?

Starts here1:51How is Coal Formed? – Geography for Kids | Educational Videos by MocomiYouTube

What are the major factors that determine whether a coal seam is economically and geologically suitable for mining?

Coal seams can be mined by surface or underground methods (Figure 4.3), with the choice of mining method dictated by both technical and economic factors. The most important technical factors are the thickness of the coal seam, the depth of the coal seam, the inclination of the seam, and the surface topography.