Question

Which of the varieties of coal is used for domestic purposes and why?

Answer 1

Hint: Coal is a combustible black or brownish-black sedimentary rock, formed as rock strata called coal seams. A good quality coal which is also efficient and provides enough heat or fire and easily available is used for domestic purposes.

Complete Answer:
There are mainly four types of coal.
They are divided into different kinds on the basis of their quality and amount of carbon content.
1. Anthracite- It is the best type of coal, it is dark black and solid. it contains about 90-95% of the carbon content. It has very little moisture due to which it does not make smoke when burnt. It is also the oldest type of coal having formed from biomass that was buried 350 million years ago. It is found in very less quantity in Jammu and Kashmir.

2. Bituminous - It is the second best type of coal, it is also solid and contains about 75-85% of the carbon content, it contains very little moisture due to which it does not make smoke. It is about 300 million years old. It is used in steel and cement industries and to generate electricity. It is also used for domestic purposes. It is found in Jharkhand, West Bengal, Odisha, Chhattisgarh and Madhya Pradesh.

3. Sub bituminous - This is a slightly better type of coal than lignite. It contains about 70-75%% of carbon content. It is of higher quality than lignite coal but of poorer quality than bituminous.

4. Lignite - It is soft, brown coal which is considered to be the worst type of coal. it contains very low amounts of carbon, about 60-70% and very high amounts of moisture, due to which it causes a lot of pollution if burnt. It is found in Rajasthan, Lakhimpur (Assam), and Tamil Nadu.

Anthracite coal is the most suited coal for domestic purposes as it contains a good amount of carbon and has high heat value. But it is available in small quantities in India and it is expensive too. Therefore bituminous coal is the most used coal for domestic purposes.

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