MaheswariBrothers : : FAQ

FAQ

What is coal?
How was/is coal formed?
What are the Four Major Types of Coals?
How is Coal Mined?
What is Reclamation?
What is Coal used for?
How is coal Transported?
What is the difference between thermal, steaming, coking, metallurgical, soft, Export and Domestic Coal?

WHAT IS COAL?

Coal is a burnable carbonaceous rock which means a rock that contains organic matter (plant and animal residues) and lots of carbon and other elements (hydrogen, oxygen and nitrogen, among others). But it also has various amounts of mineral matter, and is also considered a mineral of organic origin. Coal is also a fossil fuel - a substance containing the remains of once-living plants and animals that can be burned to release energy.

HOW WAS/IS COAL FORMED?

During the carboniferous period of geologic time (280 to 345 million years ago) scientists believe that great quantities of vegetation and other organic matter collected and underwent slow decomposition. This occurred mainly in swamps and in lagoons and a spongy, brown material called peat was formed. Geologic forces buried the peat deep under the Earth's surface and layers of peat were further compacted by heat and pressure. The compressed peat was eventually converted to coal. The greater the heat and pressure, the harder the coal.

WHAT ARE THE FOUR (4) MAJOR TYPES OF COAL?

Lignite - A brownish-black coal with generally high moisture and ash content, and the lowest carbon content and heating value.

Sub-Bituminous - A dull black coal with a higher heating value.

Bituminous - A soft, intermediate grade of coal that is the most common and widely used in the United States.

Anthracite - The hardest type of coal, consisting of nearly pure carbon. Anthracite has the highest heating value and lowest moisture and ash content.

HOW IS COAL MINED?

There are two basic ways to mine coal. Surface mining is used when coal is found close to the surface or on hillsides. This method essentially involves removing the overburden (earth and rock covering the coal) with heavy earth-moving equipment, scooping out the coal, replacing the excavated soil and reestablishing vegetation and plant life, a process known as reclamation. The advantages of surface mining are many. Where it can be used, it permits recovery of 90 percent or more of the coal to be mined.

Underground mining is used to extract coal lying deep beneath the Earth's surface or in seams exposed on hillsides. The coal is reached by drilling two openings into the coal bed to transport workers and equipment and to send coal to the surface. Both openings serve to circulate air in the mine. Coal is then broken up and mined by one of several methods:

Conventional mining - The older practice of using explosives to break up a coal seam.

Continuous mining - A huge machine with a large rotating steel drum equipped with tungsten carbide teeth scrapes coal from a seam at high speeds.

Long wall mining - A cutting machine with a large rotating steel drum which is dragged back and forth across a "long wall" or seam of coal. The loosened coal falls onto a conveyer belt for removal from the work area. After coal is extracted it is removed by automatic extraction systems that cut the coal which is loaded on shuttle cars to a central loading area in the mine or placed on belt conveyors which remove coal to the surface.

WHAT IS RECLAMATION?

As coal is removed from one section of a surface mine, the land at another part is returned, regraded and replanted so it will be as good as or better than it was before mining began. This process is called reclamation. Because of it, modern surface mining is a temporary land use, involving not just excavation or extraction of the coal, but also restoration and return of the land to productive use. Reclaimed land has been successfully used for wildlife preserves, golf courses, recreational parks, sites for commercial development, pasture land, native habitats and productive farmland

WHAT IS COAL USED FOR?

Coal's primary use is for the generation of electricity. In fact, coal generates 56 percent of the electricity consumed in America each day, far more than any other energy source. Worldwide, it provides 40 percent of total electricity generation. Coal is also used in the industrial and retail sector as a fuel for heating and powering foundaries, cement plants and other industrial and manufacturing facilities. A number of coal generation plants also use coal to produce steam for generating electricity and for heating. Coal is still used in the iron and steel industr

HOW IS COAL TRANSPORTED?

Shipping coal to market is a big business. Most coal sent from mine to market travels either by rail or by Trucks.

WHAT IS THE DIFFERENCE BETWEEN THERMAL, STEAMING, COKING, METALLURGICAL, SOFT, EXPORT AND DOMESTIC COAL?

Thermal coal is used as a fuel to produce steam for the generation of electricity and in manufacturing processes requiring heating. The coal typically has high specific energy and high volatile matter content.

Steaming coal is another term for thermal coal.

Coking coal is heated in ovens to create coke which is an essential ingredient in the steel making process.

Metallurgical coal is another term used for coking coal. The coal typically has a low volatile matter content, high rank and low impurities.

Soft coking and hard coking coal are relative terms used to describe variations in the strength of the coke used for steel manufacture.

Export coal is a quality reference to coal that meets specific standards for shipment to overseas markets. To compete in the global market place the best available coal is exported.

Domestic coal is coal consumed locally, mainly by the steel manufacturing and power generation industries.

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