Question

Which is the best quality coal?
A. Anthracite
B. Bituminous
C. Lignite
D. Peat coal

Answer 1

Hint:
> Best quality of coal is the one that burns slowly and generates great heat with less smoke.
> Its carbon content is 80-95% and is also known as “hard coal”.
> It constitutes about 1% of global coal reserves and is mined only in a few countries in the world. Majority of its global production takes place in China.

Complete answer:
There are four major kinds (or “ranks”) of coal. Steps in the slow, natural process called “coalification,” are classified and described by rank, during which buried plant matter changes into a thicker, drier, more carbon-rich, and harder material.

Slightly different parameters are used in different countries but generally proceed in increasing order from lignite, to sub-bituminous, to bituminous, to anthracite coal. Different parameters are often tested to differentiate coal ranks.

Anthracite: The highest rank of coal. It is a hard, brittle, and black lustrous coal, often referred to as ”hard coal” which has a high percentage of fixed carbon and a low percentage of volatile matter.

Bituminous: Middle-rank coal between sub-bituminous and anthracite. It generally has a high heating value and is the most common type of coal used in generating electricity in the United States of America. Bituminous coal appears shiny and smooth when you first see it, but on looking closely you will be able to see the layers.

Sub-bituminous: It is black in colour with a dull appearance. Its heating value is higher than lignite.

Lignite: Also known as “brown coal”, is the lowest grade coal with the least amount of carbon.

The heating value (also known as energy value or calorific value) of a fuel is the amount of heat released during the combustion of a specified amount of it.

Therefore, the correct answer is A

Note:
> Peat is not actually coal, but rather the precursor to coal.
> Peat is a soft organic material consisting of partially decayed plants and, in some cases, deposited mineral matter.
> Under high pressure and heat, it becomes coal.