Question

What are different varieties of coal

Answer 1

there are 6 types if coal
1-peat
2-lignite
3-stream coal
4-graphite
5-bituminous coal
6-anthracite

Answer 2

Lignite or Brown Coal– It is considered to be the coal of lowestrank as it is the youngest of all. It only contains nearly 25-35 percentof carbon. It is usually used for generation of electric power. As it contains less carbon, it is higher in moisture content and sulphur content.It has low calorific value (8000kj/kg to 15000kj/kg) and it usually admired for its low cost. Its energy density is also low, and therefore does not seem to be a good choice for transportation. It is estimated that nearly 17 percent of the world coal reserves are lignite. It is usually crumbly and powdery.Sub bituminous Coal– This coal is also known as black Ignite. It contains 20 to 30 percent moisture and 35 to 45 percent carbon. This coal is also generally used for generation of electricity. It is admired for its low mining cost and lower prices.This coal is not as hard as bituminous coal. It appears blackish brown. Its caloric value ranges from 4000 kcal/kg to 5800 kcal/kg. Its rank is in between lignite and bituminous coal. Ligniteand sub bituminous coals are together considered as low rank coals and have more reserves than high rank coal in the world. These low rank coals have lower ash content and higher reactivity thanin comparison to high rank coals.Bituminous Coal – This coal is dark and hard. This coal is formed when a sub bituminous coal undergoes a higher level of organic metamorphism. The carbondensity of this coal is higher and accounts nearly 77 to 87 percent ina dry ash free basis; it is further divided into low volatile, high volatile and medium volatile types. It is used for the generation of electricity, making coke for the steel industry, etc.It is further divided into Thermal and Metallurgical types. Thermal coal is also known as steaming coal as it is primarily used for producing steam for electricity, whereas metallurgical coal is