GK
GENERAL SCIENCE
|
Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
|
|
|
Lignite
|
|
|
Anthracite
|
|
|
Bituminous
|
|
|
Peat
|
Detailed explanation-1: -Anthracite: The highest rank of coal. It is a hard, brittle, and black lustrous coal, often referred to as hard coal, containing a high percentage of fixed carbon and a low percentage of volatile matter. Bituminous : Bituminous coal is a middle rank coal between subbituminous and anthracite.
Detailed explanation-2: -Anthracite is a hard, compact variety of mineral coal that has a high luster. It has the highest carbon count and contains the fewest impurities of all coals, and has the highest calorific content as compared to other types of coals such as bituminous coal and lignite.
Detailed explanation-3: -Anthracite coal is categorized into three types of grades. These are (i) semi-anthracite or standard grade, (ii) anthracite or high grade, and (iii) meta-anthracite or ultra-high grade. Semi-anthracite grade has a carbon content of 86 % to 92 % and a volatile matter (VM) content in the range of 8 % to 14 %.