Coal is divided into anthracite, bituminous coal and lignite. Anthracite: It is a hard, dense and high-gloss coal mine variety. Among all kinds of coal, anthracite has lower calorific value, but the highest carbon content and the least impurity content. Bituminous coal: It is the product of further metamorphism of coal, with a moderate degree of coalification. Black, hand dyed, dense and fragile, with black stripes and thick smoke when burning, so it is called bituminous coal. Brown coal: also known as firewood coal, it is a mineral coal with the lowest degree of coalification, and it is a brown-black, dull low-grade coal between peat and asphalt coal.

Coal is divided into anthracite, bituminous coal and lignite.

1, anthracite: a hard, dense and high-gloss coal mine variety. Among all kinds of coal, anthracite has lower calorific value, but the highest carbon content and the least impurity content.

2. Bituminous coal: it is the product of further metamorphism of coal, with a moderate degree of coalification. Black, hand dyed, dense and fragile, with black stripes and thick smoke when burning, so it is called bituminous coal.

3. Lignite: also known as firewood, is a kind of mineral coal with the lowest degree of coalification, and it is a brown-black, dull low-grade coal between peat and bituminous coal.