Quarrying is a form of surface mining used when the rock is close to the surface of the land. This is used for stone or rock to make buildings. The quarry is an open pit mine and is less deep than other kinds.
The way that quarrying is done depends on the rock that the miners are trying to get out of the ground and what the rock will be used for after itís mined. For example, if they want to get an ingredient of cement, they will use explosives to break the rock into small bits. This is okay because cement needs to be in small pieces when it's sold. If they want larger pieces of granite for kitchen countertops, the miners will drill holes in the rock, long distances apart. Dynamite will be packed into these and the blast will separate large slabs of granite that will be Ďslicedí with wire saws.
There are other ways to quarry such as drilling holes, blasting dynamite to make an opening, and then blowing in compressed air [or water] that splits the rock.
One of the biggest problems for quarries is drainage. Many quarries are dug in hillsides so that water can drain better. Water flows into the quarry from the surface and from the ground. The quarry needs to be pumped out to get rid of it. This adds to the costs of quarrying the rock. When the mining is over, the area can become a landfill that is filled with refuse and garbage until it fills the pit and is covered over with layers of dirt. This is called reclamation. In our area, most quarries are abandoned and left as a giant pit. Then they refill with water and become a small pond or lake. This may sound nice, but most of our quarries are considered to be unsafe, unstable, unusable, and a safety problem.
Types of machinery in quarries: