University:
Sam Houston State University
Course:
GEOL 1405 | Geologic & Environmental Hazards
Academic year:

2023
Views:

170

Pages:

10
Author:

larbiwxcvbn

COAL • A combustible black or brownish-black sedimentary rock composed mostly of carbon and hydrocarbons. It is the MOST ABUNDANT fossil fuel in the US. COAL Formation Takes a LONG Time Mining Coal: 2 Methods • Surface Mining – Method 1 • Least expensive method. • Used when coal is less than 200 ft below the surface. • Topsoil layers are removed and then REPLACED after coal layer has been extracted, allowing for the area to be re-planted or used for other natural sites. • In the US, it is mandatory that land be returned as closely as possible as was its original state prior to coal removal. Surface Mining of Coal Removes Land From Agriculture Production COAL MINING Method 2: Underground Mining • Also called Deep Mining, used when deposits are between 200ft and 1,000ft deep. • Elevators must be used to haul machinery and personnel. • Expensive process, includes much specialized machinery. • Risk of cave-ins and suffocation hazards. COAL Mining Operations are Hazardous, Especially Deep Mining. COAL Must Be Processed to Increase the Heating Value and Allow for Cleaner Burning • Common impurities are removed : • • • • • Rocks Ash Sulfur Dirt Other unwanted materials THERE ARE FOUR TYPES OF COAL WE USE FOR FUEL The US has the world’s largest known coal reserves, over 267 billion tons, enough to last over 200 years at the current usage rate. (http://factsonenergy.com/wp-content/uploads/2007/09/coal_most_abundant_energy_source.pdf Burning COAL = Pollution • Nearly 50% of the nitrogen oxide (Nox) in the atmosphere and 70% of sulfur dioxide are direct result of emissions released when coal is burned. • These are directly responsible for crop failures from “acid rain” formation (later explained in this presentation).