Coal

November 24, 2012 1:27 am

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Coal
Let’s imagine for a moment that there was no coal. Hey, who turned out the lights? And why isn’t the refrigerator working, or the TV? Much of the electricity we use comes from coal.
Coal is a black rock. It produces energy when it burns. The Chinese were mining and using coal for fuel over 3,000 years ago. It once powered the world’s industry. It helped make the United States a wealthy nation. Coal-burning trains carried people and products across the country. Today, coal-burning power plants produce electricity for many homes and businesses.
WHAT IS COAL?
Coal is mostly made up of the element carbon. When carbon burns, it releases a large amount of energy as heat. That’s what makes coal such a useful fuel.
Coal is a fossil fuel. That means it comes from the remains of ancient life buried deep in ’s crust. The coal we use today started out as plants that grew in swamps millions of years ago. When the plants died, they settled to the swamp bottom. Over time, layers of mud and rock formed. They compressed and hardened the plant material. Heat and pressure caused chemical changes. Gradually, the once-living matter became coal.
COAL MINING
Coal deposits are found in many parts of the world. Taking these deposits from the ground is called coal mining.
Some coal deposits lie close to Earth’s surface. They can be mined by scraping away the dirt and rock. This is called surface mining, or strip mining.
Other deposits lie deep underground. Miners must drill and blast deep holes in order to reach them. They bring machinery down to dig out the coal. This is called underground mining, or deep mining. Underground mines can be more than 1,000 feet (300 meters) deep. Their tunnels can be several miles long.
Deep mining is a dangerous job. Cave-ins, fires, and explosions are some of the dangers. Coal mining can also release poisonous gases. In the 1800s, miners would bring small birds into the mines as a safety alarm. If a bird died, it showed that there was poisonous gas in the mine. Today, miners use machines to test the air.
Surface mining is cheaper, easier, and safer than deep mining. But it scars the land. It can also create pollution and cause the soil to wash away.
HOW DO WE USE COAL?
A century ago, coal powered the steam engines that ran most machinery. Once, most American homes and office buildings were heated by coal-burning furnaces. Most of these jobs are now done by oil or natural gas.
Five-sixths of the coal mined today in the United States is used in electric power plants. Coal is also used in making iron and steel and in the cement- and paper-making industries.
PROBLEMS WITH COAL
Like other fossil fuels such as oil, coal is a nonrenewable resource. This means that once it’s used up, it’s gone. But the United States has a lot of coal. It would take hundreds of years to use it all.
Burning coal causes air pollution. Chemicals in coal can produce “acid rain.” Acid rain kills plants and pollutes rivers. However, machines called scrubbers can keep most of this pollution from getting into the atmosphere.
Burning coal also releases gases that cause global warming. These gases trap heat from the Sun. The trapped heat warms up the planet. Global warming could cause icecaps to melt and change Earth’s climate. Burning all of the coal available to us would be bad for the environment.
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