Burning characteristics of coal

I unloaded my stove this morning and started a fresh fire. Very little loose ashes,majority was in chunk form.Most all the chunks had a layered look.Does that signify high ash/low fusion temp? Clinkers? What about pieces that look like charcoal coated with ash?

Sorry for all the questions but I'm trying to get a better understanding of coal burning.

you might have had more burn time left and shook it too soon. it hasnt been as cold for me lately and ive been having a longer burn time too. maybe thats it.

You maybe right.Time will tell. It's going to get cold again real soon. Overnight lows down to 5*.

i dont do well with the hand fed stoves cause i tend to mess with the fire too much, yes i have a lot to learn about burning coal also......and i have my hands full......3 stoves here that always need maintenance and........a boiler pipe broke at my lady friends house and ruined alot of the contents of the basement including the alaska stoker down in the basement, and the stove pipe i installed last year is all rotted away also......i cant even get the door open on the alaska, her and her mother have not been downstairs because of the mold that the contractor did not kill yet......mold does not bother me, maybe it will make me stronger.......i cant see a 2500 dollar stove go to waste while her mother runs the oil fired boiler and theres still coal in the bin....what i'm getting at here is that the coal from that valley burns alot different than the coal we use here.......our coal puts off more heat, and nicer looking ash

the powered chunks are ok, and some of the black pieces you are finding may be shale or the fire is going out around the edges....we lightly poke the coal esp the edges twice a day before we shake it on the kenmore and the warm morning