Bituminous Coal

Use and Composition

Bituminous coal is burned for steel production rather than electricity production. Bituminous coal may also be referred to as metallurgical coal or coking coal. This coal is ideal for steelmaking because it has a carbon content of 70–90%, low impurities, and is dense in energy. Bituminous coal is dense yet brittle, dark brown to black in color, and possibly has a shiny appearance. Because it is brittle, coal rocks can fragment, creating smaller particles that can then be uplifted into the atmosphere by winds or motion, for example, on moving train cars.

Volatile matter (VM) content determines how much gas and liquid release when coal is heated, and also define its coking ability. Bituminous coal, with medium VM content (21-33%) is practical for metallurgical applications, since they have optimal behavior in furnaces and reasonable coke strength. Ash content measures the remaining matter after the coking process. High phosphorus (P) and sulfur (S) content from this fraction also could contaminate the final steel product. Therefore, the coal ingredient needs to be low in these impurities to produce the best steel quality.

Another sub-group of elements in coal are chalcophile (i.e., sulfur-loving) elements. These elements show up with the presence of sulfur in coal and attach sulfur in sulfide phases (i.e,. pyrite, iron sulfide, FeS₂) from the formation process. These elements include toxic metals such as lead (Pb), selenium (Se), arsenic (As), cadmium (Cd) and mercury (Hg), which are known cancer-causing agents with adverse health effects. Despite their low levels, trace abundance; frequent and chronic exposure from these elements over a long period could prolong their toxicity and affect public health [5]. When coal is mined, crushed and transported, these elements can prevail in coal dust and come into contact with nearby communities.

Geological Formation

Bituminous coal was formed from ancient tropical swamps 300 million years ago and is mined today in locations that include the coal seams of the Appalachian Basin in West Virginia.

Coal mined in the Appalachian Basin is transported by rail to major East Coast ports for global distribution, including the Port of Virginia, which consists of the Dominion Terminal Associates and Kinder Morgan Bulk Terminals in Southeast Newport News and the Norfolk Southern Terminal in Lambert's Point, Norfolk, as well as Curtis Bay in Baltimore, Maryland.

Documents

• Milici et al., Bituminous Coal Production in the Appalachian Basin: Past, Present, and Future, Chapter D.3 of Coal and Petroleum Resources in the Appalachian Basin: Distribution, Geologic Framework, and Geochemical Character, Edited by Ruppert and Ryder, Professional Paper 1708-D.3, U.S. Department of the Interior, U.S. Geological Survey, 2014
• Tewalt et al., Coal Assessments and Coal Research in the Appalachian Basin, Chapter D.4 of Coal and Petroleum Resources in the Appalachian Basin: Distribution, Geologic Framework, and Geochemical Character, Edited by Ruppert and Ryder, Professional Paper 1708-D.4, U.S. Department of the Interior, U.S. Geological Survey, 2014