How is coal extracted from mountaintop removal mines?

I may be wrong but I believe they blow up the mountaintop then drill it out.
Sorry if it doesn't help.

Coal can be extracted from the mountain top removal mines in two ways, such as-

Open cast mining- Here various mining techniques are used to excavate at the surface, in order to extract the coal from it.Underground mining- Here, underground excavation is done to obtain the coal from the subsurface. It is a very costly mining method and risky at the same time, compared to the open cast mining.

They can measure  the amount of energy gained or lost

Aconductor easily transfer heat