Sphalerite is obtained from underground mining. It is a zinc ore that is formed in veins, which are long layers of rocks and minerals that form underground. Found in sedimentary, igneous and metamorphic rock, sphalerite is mined in many different places around the world, such as Mexico, Australia, Italy, Spain, Germany and various places in the United States. There are sphalerite mines in Illinois, Missouri, Kansas, Oklahoma, Tennessee and even in New Jersey. Sphalarite is an important compound because it is used to make zinc, which in turn is used to make various rubber and paint products, as well as chemicals and medicines.
Sphalarite accumulates in deposits that can extend far underground. For this reason, underground mining is the method of choice to retrieve it. Other mining methods, like surface mining, would be far too expensive and difficult. One way to determine that underground excavation is more beneficial is by calculating what is known as the strip ratio. This is the total amount of waste material that needs to be removed in proportion to the amount of ore. The point of underground mining is to extract as little waste as possible.
An underground mine is comprised of a sophisticated network of tunnels, shafts and equipment. It is entered through a shaft, a horizontal tunnel or an adit, which is a nearly horizontal entryway. Several levels make up most underground mines, and the actual sphalarite or other ores are mined in rooms called stopes. As it is drilled or blasted out, enough material is left in place to support the ceiling, so the mine doesn’t collapse.
The sphalarite mining process involves a wide variety of equipment. Continuous mining machines can be used, which cut through rock and haul it up, even separating the usable ore from waste rock, all in one system. Dump trucks are common in mining operations, and ship off material to the appropriate locations, or even to and from different parts of the mine. Shuttle cars have been used in the past to load material and move it out of the mine. Usually, trucks are now used--but the shuttle cars are still associated with mining, as they are typically seen in movies with mining scenes.
Modern-day underground mining is a highly technological, mechanized process. Sophisticated vehicles, rail systems and state-of-the-art drilling systems are bought from manufacturers and suppliers. Ventilation systems pump in fresh air while removing poisonous gases and dust. Also, the roof is supported by timber, concrete or even steel supports. Steel rods are often used to hold the roof to the interior rocks.
The current methods of underground mining make sphalarite mining relatively safe. It is a productive process--and it needs to be, since the ore is so commonly used to make many products that industry and consumers depend on.