Welcome, One word of caution, most the coal from a power plant is not clean enough to use in a blacksmith forge. most the time.
The bituminous claol I am using is less than .75% sulfur 2.13% ash 13,800 BTUs. this is the extra clean Sewell seam coal.
the key is low sulfur, as its not good for steel, the low ash means reduced clinkers. IF the coal your power plant has too high sulfur, as is the case for most as the cost of the low sulfur is much higher, ya can be a problem to work with, and Anthracite is very hard to keep burning, I wont even get into the problems of trying to use Lignite. Shop around for blacksmithing coal, aka Stoker, and using them side by side you will see a major difference.