Differences between Anthracite and Bituminous

Coal

Anthracite Coal Bituminous Coal1. Anthracite is a harder, glossy, black and compact variety of mineral coal.

1. Bituminous Coal is relatively less hard and less compact quality of coal. It is usually Black or sometimes Dark Brown in color, often with well-defined bands of bright and dull material.

2. The term Anthracite is applied to those varieties of coal which do not give off tarry or other hydrocarbon vapors when heated below their point of ignition.

2. Bituminous Coal contains relatively larger percentage of tarry and other volatile compounds. That is why when it is heated below its point of ignition these volatile compounds like methane and ethane are evolved.

3. The very small percentage of tarry and other volatile compounds in Anthracite makes it use directly without further processing.

3. ● As Bituminous Coal contains relatively larger percentage of tarry and other volatile hydrocarbons, it is further processed before use and coking is done. That is Bituminous Coal is converted into COKE.● Anthracitization is the transformation of bituminous coal into anthracite coal. Bituminous Coal undergoes some geological changes in Anthracitization.

4. It has the highest carbon count and contains the fewest impurities of all coals. Its carbon content is between 92% and 98%, the rest is composed of water, air, hydrogen, and sulphur.

4. The carbon content of bituminous coal is around 60-80%, the rest is composed of water, air, hydrogen, and sulphur which have not been driven off from the macerals.

5. It is low sulfur and high BTU coal.

5. It is relatively high sulphur, less carbon and less BTU coal.

6. The heat content of anthracite ranges from 22 to 28 million Btu per short ton (26-33 MJ/kg) on a moist, mineral-matter-free basis.

6. The heat content of bituminous coal ranges from 21 to 30 million Btu/ton (24-35 MJ/kg) on a moist, mineral-matter-free basis.

7. It is also free from included soft 7. It may contain soft or fibrous

or fibrous notches and does not soil the fingers when rubbed.

notches and can soil the fingers when rubbed.

8. Anthracite ignites with difficulty and burns with a short, blue, and smokeless flame. It burns cleaner, hotter and longer than any other coal. These properties make it ideal for home heating use.

8. It is of better quality than lignite coal but of poorer quality than anthracite coal. Its Flame is also less hot and produces black smoke as well. Also its flame remains for less period of time. That is why it is not useful as domestic fuel.

9. Anthracite coal is the highest of the metamorphic rank.

9. Bituminous coal is an organic sedimentary rock formed by digenetic and sub metamorphic compression of peat bog material.

10. It has higher relative density of 1.3-1.4

10. It is less dense than Anthracite But denser than Lignite Coal.

11. It has a high luster, which is often semi-metallic with a mildly brown reflection.

11. Bituminous coal seams are stratigraphically identified by the distinctive sequence of bright and dark bands and are classified accordingly as either "dull, bright-banded" or "bright, dull-banded" and so on.

12. The moisture content of Anthracite is less than 0.7 percent.

12. The moisture content of Bituminous Coal is 1-13 percent.

13. The thermal conductivity is also higher, a lump of anthracite feeling perceptibly colder when held in the warm hand.

13. The thermal conductivity is also relatively less, as holding a lump of bituminous in the warm hand does not give the cold feeling as Anthracite does.

14. The principal use of anthracite today is for a domestic fuel in either hand-fired stoves or automatic stoker furnaces. It delivers high energy per its weight and burns cleanly with little soot, making it ideal for this purpose. Its high value makes it prohibitively expensive for power plant use. Other uses include the fine particles used as filter media. Anthracite coal is by far the least

14. It is used primarily as fuel in steam-electric power generation, with substantial quantities also used for heat and power applications in manufacturing and to make coke. During carbonization, coking coals undergo transformation into plastic state at around 350 to 400°C swell and then resolidify at about 500o-550o C to give semi-coke and then coke. In coke

expensive fuel you can use to heat your home providing you live near the Eastern Pennsylvania area where it can be purchased for a reasonable price. It is used primarily for residential and commercial space heating.

ovens, after coal is charged inside the oven, plastic layers are formed adjacent to the heating walls, and with the progress of time, the plastic layers move towards the centre of oven from either side and ultimately meet each other at the centre. During coke making, two opposite reactions take place, viz. condensation and pyrolysis.On average, it took about 1.43 tons of coal to produce a ton of coke.

15. Anthracite coal may be considered to be a transition stage between ordinary bituminous coal and graphite, produced by the more or less complete elimination of the volatile constituents of the former; and it is found most abundantly in areas that have been subjected to considerable earth-movements, such as the flanks of great mountain ranges. Anthracite coal is a product of metamorphism and is associated with metamorphic rocks, just as bituminous coal is associated with sedimentary rocks.

15. Bituminous coal has been compressed and heated so that its primary constituents are the macerals vitrinite, exinite, etc.Bituminous Coal is the stage which undergoes further physical and chemical changes caused by Geological changes and Semi-anthracite and then Anthracite is produced.Bituminous Coal is the result of sedimentation of the trees. So unlike Anthracite, it is associated with Sedimentary Rocks.