The hardest type of coal, consisting of nearly pure carbon, is: The correct answer is c – anthracite. Anthracite is the hardest type of coal; it has the highest heating value and lowest moisture and ash content.
What is the hardest coal called?
Which of these is the hardest and oldest type of coal?
What are the 5 types 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 is the cleanest type of coal?
Where is the best coal in the world?
Which country has the cleanest coal?
Is Coal still being formed?
The process of coal formation is still taking place today, says Bailey. “The precursor to coal is called peat, and that is just uncompressed plant matter.” Peat accumulates in wet swampy environments known as mires, and that process is taking place today in areas such as Indonesia and even the Antiplano in the Andes.
Which coal has highest ash content?
What is the youngest form of coal?
What type of rock is coal?
Coal is a combustible sedimentary rock formed from ancient vegetation which has been consolidated between other rock strata and transformed by the combined effects of microbial action, pressure and heat over a considerable time period. This process is commonly called ‘coalification’.
What classification is coal?
Based on maceral content and its appearance in a hand specimen, coal is classified into four principal types: clarain, durain, fusain, and vitrain. Coal may also be classified in grades using subjective terms (e.g., “low-sulfur coal,” “high-ash coal”) with reference to their impurities for commercial purposes.
Does coal absorb water?
Coal is known to absorb water when soaked in it. … Therefore it is very important, in judging whether a coal will make a good CWM, to know the factors which influence its moisture- holding capacity.
Which coal has highest water content?
- Anthracite coal is a dense, hard rock with a jet-
- 86% and 98% carbon by weight, & it burns.
- Bituminous coal (in Indiana), contains between.
- 69% & 86% carbon by weight.
- Sub-bituminous coal contains less carbon, more.
- Lignite coal, or brown coal, is a very soft coal that.
- contains up to 70% water by weight. Emits more.
Which gas is released when coal is burnt?
Why is brown coal bad?
Because of its low energy density and typically high moisture content, brown coal is inefficient to transport and is not traded extensively on the world market compared with higher coal grades.