Coal - Wikipedia
Coal is a combustible black or brownish-black sedimentary rock, formed as rock strata called coal seams. Coal is mostly carbon with variable amounts of other elements, chiefly hydrogen, sulfur, oxygen, and nitrogen. [1] .
Coal | Uses, Types, Pollution, & Facts | Britannica
2024年10月23日 · Coal is defined as having more than 50 percent by weight (or 70 percent by volume) carbonaceous matter produced by the compaction and hardening of altered plant remains—namely, peat deposits.
Coal explained - U.S. Energy Information Administration (EIA)
2023年10月24日 · Coal is a combustible black or brownish-black sedimentary rock with a high amount of carbon and hydrocarbons. Coal is classified as a nonrenewable energy source because it takes millions of years to form. Coal contains the energy stored by plants that lived hundreds of millions of years ago in swampy forests.
What is coal? | U.S. Geological Survey - USGS.gov
Coal is a sedimentary deposit composed predominantly of carbon that is readily combustible. Coal is black or brownish-black, and has a composition that (including inherent moisture) consists of more than 50 percent by weight and more than 70 percent by volume of carbonaceous material.
Coal - Education | National Geographic Society
2024年10月15日 · Coal is a black or brownish-black sedimentary rock that can be burned for fuel and used to generate electricity. It is composed mostly of carbon and hydrocarbons, which contain energy that can be released through combustion (burning).
Coal - Plant Matter, Carbonization, Sedimentary Rocks | Britannica
2024年10月23日 · It is generally accepted that most coals formed from plants that grew in and adjacent to swamps in warm, humid regions. Material derived from these plants accumulated in low-lying areas that remained wet most of the time and was converted to peat through the activity of microorganisms.
Coal: Anthracite, Bituminous, Coke, Pictures, Formation, Uses
Coal is an organic sedimentary rock that forms from the accumulation and preservation of plant materials, usually in a swamp environment. Coal is a combustible rock and, along with oil and natural gas, it is one of the three most important fossil fuels.
Coal - Anthracite, Bituminous, Lignite | Britannica
2024年10月23日 · Coal - Anthracite, Bituminous, Lignite: Coals contain both organic and inorganic phases. The latter consist either of minerals such as quartz and clays that may have been brought in by flowing water (or wind activity) or of minerals such as pyrite and marcasite that formed in place (authigenic).
How does coal form? - Live Science
2022年12月26日 · Coal forms when swamp plants are buried, compacted and heated to become sedimentary rock in a process called coalification. "Very basically, coal is fossilized plants," James Hower, a...
The Types of Coal: Composition, Usage, and Energy Value
2021年9月1日 · Coal is a sedimentary black or dark brown rock that varies in composition. Some types of coal burn hotter and cleaner, while others contain high moisture content and compounds that contribute to acid rain and other pollution when burned.