What is coal mining?
Coal mining is the process of extracting coal from the ground. Coal, since the 1880s, has been widely used to generate electricity. As one kind of energy, steel and cement industries use coal as a fuel for extraction of iron from iron ore and for cement production.
Coal is the most abundant fossil fuel on Earth. Its predominant use has always been for producing heat energy. It was the basic energy source that fueled the Industrial Revolution of the 18th and 19th centuries, and the industrial growth of that era in turn supported the large-scale exploitation of coal deposits.
Since the mid-20th century, coal has yielded its place to petroleum and natural gas as the principal energy supplier of the world. The mining of coal from surface and underground deposits today is a highly productive, mechanized operation.
How does coal mining work?
To start coal mining work, there are many guidelines and rules to be followed.
For environmental protection, the local government usually has rules to control all activities in coal mining process. They need to check the coal mining operator qualification, company status and then issue a certificate to allow the company to go on.
Regulations are specific rules the company needs to follow in the mining process. In each country, there will be different regulations in the industry.
Take Pennsylvania for example, the following chapter of the Pennsylvania code is basis for coal mining. So if you run coal mining in this area, you must follow this regulation.
Underground mining or surface mining
There are two main methods for coal mining. Surface mining and underground mining.
Firstly, let us talk about surface mining. There are three kinds of surface mining.
Strip mining is used where coal seams are located very near the surface and can be removed in massive layers, or strips.
Overburden is usually removed with explosives and towed away with some of the largest vehicles. Dump trucks used at strip mines often weigh more than 300 tons and have more than 3,000 horsepower.
Open-pit mining is used when coal is located deeper underground. A pit is dug in an area. This pit becomes the open-pit mine, sometimes called a quarry. Open-pit mines can expand to huge dimensions, until the coal deposit has been mined or the cost of transporting the overburden is greater than the investment in the mine.
Open-pit mining is usually restricted to flat landscapes. After the mine has been exhausted, the pit is sometimes converted into a landfill.
Due to environmental protection, now governments are strict to allow companies to use this method for coal mining.
Mountaintop removal mining (MTR)
MTR means mountain removal mining, the entire top cover of a mountain is stripped of its overburden: rocks, trees, and topsoil.
MTR is probably the most controversial coal mining technique. It destroys all rocks, trees and all others on the mountain. Waterways on mountain are cut off. Habitats are destroyed. When the strong wind comes, the air pollution is severe. Toxic byproducts of the mining and explosive processes can drain into local waterways and pollute the air.
Compare with surface coal mining, let’s talk about underground coal mining.
Underground mining, also known as deep mining, is a process that retrieves coal from deep below the Earth’s surface—sometimes as far as 300 meters or more. Miners take an elevator going down a mine shaft to reach the depths of the mine, and operate heavy machinery that extracts the coal and moves it above ground.
There is less dramatic than surface mining for underground mining. There is little overburden, but underground mining operations leave significant tailings. Tailings are the often-toxic residue left over from the process of separating coal from gangue, or economically unimportant minerals. Toxic coal tailings can pollute local water supplies.
What is coal mining used for?
Once the coal has been extracted, it can be used for heating and industrial processes, or to fuel power plants for electricity.
In rural areas in China, now many villages still make homes warmer by firing coals in winter. They are poor and can not afford other methods for heating homes. In cities, the government has launched laws years ago, nobody can install equipment for coal firing in winter, it is certainly for air pollution protection.
But in some provinces, such as Inner Mongolia, we also can see some power plants. There are many coal mining places in Inner Mongolia, all are in business under the government laws, but it is poor province, so the government allow some power plants to produce electricity there.