Coal: Characteristics, Formation, Location, Mining

Introduction

A mineral is any naturally occurring solid containing a precise chemical. Minerals are used daily for so many different things, such as for airplanes, computer parts, batteries, and prosthetics. They can also be studied to find out more about the past. Without them, humans would not be able to properly develop as a race. Coal, although under some definitions it is not defined as a mineral, is very important as well. It has many uses.

Characteristics

There are many different types of minerals, and they all have different characteristics. General information about mineral characteristics. Characteristics of coal depend on the type of coal. The more carbon and less water coal have, the higher its ranking.

Lignite, also called brown coal, is the lowest official ranking of coal. It is a brown color and very brittle and crumbly. It contains low amounts of carbon and therefore energy (25-35%).

Sub-Bituminous coal is also considered brown coal. It has a very similar appearance to lignite with a very dull and rough look. This type of coal has a 35-45% carbon content.

Bituminous coal is darker and has bands running down the middle of it where different plant layers were. Bituminous coal has a very large amount of carbon at 45-86%. It is denser than brown coal.

Anthracite has the highest amount of energy and a carbon content of up to 97%. It often has a black luster to it and is very hard and very dense. It is the strongest type of coal and has the lowest moisture content, containing nearly no water nor carbon dioxide.

Formation

Coal is compressed plant matter from millions of years ago. In this time, plants flourished, and the earth was covered with forests. Plants were growing very quickly, and as old plants died, new ones would grow right on top of them without giving them time to decompose. Eventually, the new plants died, and more grew on top of them. This process continued over millions of years, creating many separate layers underneath the earth’s surface. The weight of the upper layers compressed the plant matter. The layers were under an incredible amount of pressure and the temperature was very high, causing physical and even chemical changes in the plant layers as the oxygen was forced out, leaving carbon deposits. This process created coal.

Location

Where coal is found on also depends on the type of coal. Also, because of the unique way coal was made, it is found in almost every country in the world, but certain countries have more coal, or more of a specific kind. The lower ranking coals are found mostly in the United States, China, and Australia. Higher rankings are found in the US too, and Russia. Anthracite is mostly found in Pennsylvania, Vietnam, Russia, and Ukraine.

Mining

There are two main ways in which coal can be mined today – surface mining and underground mining. Surface mining can only occur if the coal is less than 200 ft underground. Otherwise, underground mining must be what happens. In surface mining, the rock on top of the coal (overburden) is removed. This can be done in several different ways, depending on the landscape and the resources available.

When coal is located very close to the surface, then overburden is often removed with explosives and hauled away using large trucks. Then, it is easy to access the underlying coal. This can be done in hills or flat landscapes. This is called strip mining.

If coal is located more deep underground in a flat area, then a large pit is dug. This is called an open-pit mine or a quarry. Quarries like that can be massive in size and often grow the longer they are in use.

Surface mining is more environmentally dangerous than underground mining, but it is much cheaper. Two and a half times more coal per hour can be acquired in surface mining than in underground mining. Despite this, entire ecosystems can be destroyed, landslides can be triggered, and dangerous gases can be released.

Underground mining occurs in areas where the coal is as far as 1,000 ft down. There is an elevator from the surface down the mine for the miners, and machines carry the coal to the surface. Impacts on the habitat where the mining is taking place are less than that of surface mining, but there still are some. Toxic residue can be left over, which can contaminate water sources.

Underground mining is also more dangerous to miners than surface mining. Flooding, suffocation, toxic gases being breathed in, and cave-ins are serious problems. Methane gas must also be led out of the mine to keep miners safe from over-inhaling the gas or explosions caused by the methane.

The bell pit was one commonly used way to mine in the past, and the first known way of underground mining. It was very simplistic and consisted of a tunnel down into where the coal would be found (10-90m deep). There, it opened into a larger hole where the mining was done. The only lights inside of bell pits were candles and lamps. In some mines, coal was carried up by women and children using ladders. In others, baskets were used. Bell pits were monitored closely as nothing was keeping the roof of the mine from caving in. Once a pit was deemed to be unstable, it was abandoned and a new one was opened next to it. clearly defining how scientific and technical innovation have improved the efficiency of the collection method