The spelling of the word "hard coal" is depicted by the IPA phonetic transcription as /hɑrd koʊl/. The term "hard coal" is used to describe a type of coal that is harder and more dense than other types of coal. This coal is primarily made up of carbon and is often used for heating and producing electricity. However, due to its high sulfur content, it contributes significantly to environmental pollution. It is essential to use alternative energy sources to reduce the carbon footprint and protect the environment.
Hard coal, also known as anthracite, is a type of coal with a high carbon content and low impurities that makes it particularly desirable for use as a fuel source. It is a dense, shiny, black to gray rock that burns efficiently with little smoke and is prized for its high energy content.
Characteristically harder and more brittle than other forms of coal, hard coal is formed from the remains of woody plants in ancient swamps and marshes that have been subjected to high pressure and heat over millions of years, resulting in a higher carbon content. This increased carbon levels translate to a higher energy yield when burned as fuel, making it a particularly desirable form of coal.
Hard coal, due to its high carbon content, burns with a blue, smokeless flame and produces very little soot or volatile gases. It is commonly used in industrial processes, such as steel and iron production, where intense heat is required to reach the necessary temperatures for these operations. Additionally, it is often used as a heating fuel in residential and commercial settings, particularly in areas where it is abundant and readily available.
Due to its higher purity and energy content, hard coal is generally more expensive than other types of coal. However, the benefits it offers in terms of cleaner burning and higher energy output make it a valuable resource for various industries and applications.
The term "hard coal" is derived from the Old English word "heard", which means hard or solid. In the late 18th century, when the Industrial Revolution was underway, people needed a more efficient fuel source for steam engines and other machinery. Hard coal, also known as anthracite, became popular due to its high carbon content, low impurities, and high energy density. The term "hard coal" was used to distinguish it from the softer forms of coal, such as bituminous coal and lignite.