What are the 4 grades of coal?
Coal is classified into four main types, or ranks: anthracite, bituminous, subbituminous, and lignite. The ranking depends on the types and amounts of carbon the coal contains and on the amount of heat energy the coal can produce.
What are the characteristics of a good quality coal?
Good burning characteristics – Complete combustion without agitation. Good grindability – sometimes it is needed to grind coal before burning. Good coal should not cause high abrasion on the machine. High ash softening temperature – High Ash softening temperature lower the risk of slagging.
What is the particle size of coal?
The particle sizes of the low rank coal were varied among 45–75, 75–90, and 150–180 μm. The particle sizes of high rank coal were constant at 75–90 μm. The residence time of EDTR was about 4.5 s, which was calculated based on the gas flow rate and the reactor volume for all experiments.
What are the 5 main types of coal?
|Coal||Dry, Carbon content (%)||Dry, volatile content (%)|
What are the unique characteristics of coal?
Coal is composed of macerals, discrete minerals, inorganic elements held molecularly by the organic matter, and water and gases contained in submicroscopic pores. Organically, coal consists primarily of carbon, hydrogen, and oxygen, and lesser amounts of sulfur and nitrogen.
What is the formula of coal?
The chemical formula of coal is reported as: C135H96O9NS. Coal is usually taken as 85% carbon based on dry mass.
What is the cleanest coal?
The ranks of coal (from most to least carbon content) are as follows: anthracite, bituminous coal, sub-bituminous coal, and lignite. The coal with the highest carbon content is the best and cleanest type of coal to use.
Who has the best quality coal?
Australian coal is generally amongst the best quality coal in the world, regarded highly for its energy content, low impurity and its efficiency as a coking agent in the production of steel.
Which is the purest form of coal?
High grade (HG) and ultra high grade (UHG) anthracite are the highest grades of anthracite coal. They are the purest forms of coal, having the highest degree of coalification, the highest carbon count and energy content and the fewest impurities (moisture, ash and volatiles).