Coal mining

Coal mining is the process of extracting coal from the Earth. Coal is a valuable resource because of its high energy content. Since the 1880s, it has been used widely to generate electricity.

Different regions use different names for these operations. In the United Kingdom and South Africa, a mine is often called a colliery. In some places, a mine is simply called a "pit."

Over time, mining has evolved from manual digging to massive industrial operations. Today, we use advanced technology like draglines and hydraulic jacks to move earth and coal.

Before mining begins, experts must evaluate the technical and economic feasibility of a site. They look at regional geological conditions and the thickness of the coal seam. They also study the overburden, which is the material sitting above the coal.

Other factors include the topography, such as the slope of the land. They must also consider groundwater conditions and the availability of labor. These details determine whether a mine will be a surface mine or an underground mine.

Surface mining is used when coal seams are relatively close to the surface. This method includes techniques like open-cut, strip mining, and mountaintop removal.

In strip mining, workers remove the overburden in long strips. They often use explosives to fragment the earth first. The overburden from the first strip is placed in an area called out-of-pit dumping. For later strips, the waste is placed in the empty void, known as in-pit dumping. This process is most suitable for areas with flat terrain.

In steeper areas, miners use contour mining or mountaintop removal. Contour mining follows the shape of a ridge or hillside.

This can cause erosion or landslides if the waste is not managed correctly. Mountaintop removal involves removing the entire top of a mountain to reach coal. The leftover rock is often placed in nearby valleys, creating "valley fills." This practice is controversial because it changes the landscape and can cover streams.

These methods can leave the ridge tops as flattened plateaus.

Underground mining is used for coal located at much greater depths. This method accounts for about 60 percent of the world's coal production.

One common technique is the room and pillar method. In this process, miners create paths through the coal seam. They leave large pillars of coal standing to support the mine roof. This prevents the ceiling from collapsing onto the workers.

Some mines also use retreat mining, where miners eventually remove the pillars to recover more coal.

Coal mining has a long history of moving resources across the globe. Ships have been used to haul coal since the era of the Roman Empire.

The modern industry is massive, employing over 2.7 million people worldwide. About 2.2 million of these workers are located in Asia.

While production is falling in Europe and the United States, other nations are still growing. Major producers like China, Indonesia, India, and Australia have not yet reached peak production.

However, the industry faces significant environmental and health challenges. Mining can cause land degradation and polluted waterways through acid mine drainage.

It also contributes to global issues like poor air quality and climate change. Because of these impacts, many parts of the global energy economy are phasing out coal. This shift is expected to decrease the number of coal jobs in the coming decades.

The world is currently navigating a transition toward different energy sources.