Colorado Soft Coal Experiment

Tested bit coal sent from Carbondale, Colorado. The coal is oily, doesn't feed well because it clumps together, and produces medium, featherweight, clinkers, the kind that grow into an octopus in the pot. Although it produced clinkers, they easily fell off the sides of the pot.

The fire is hotter and smokier than with the Alaska or Wyoming coal. This will not work in the efm stoker because it doesn't feed properly with an auger. Other than that, it's OK.

stoker-man wrote:it doesn't feed properly with an auger

Because it's oil treated?
Oil treated stoker coal has been used in stokers here in Utah/Colorado for many years. These stokers are designed to use coal up to 1" in size. Maybe oiled coal doesn't work well because EFM auger is smaller?
What is the percentage of fines in the Carbondale coal?

It doesn't fall down by gravity well, into the auger. I had the coal in a bucket and it made a 2" hole that went down at least a foot down from the top to the auger and just bridged there. It's because of the oil. It kept bridging for the whole test.

Supplied from the breaker, there were no fines. I had to crush it to feed it through our smaller auger and that made fines, but I didn't think they'd make so much trouble, so I just left them in.

If the coal was rice sized with minimal fines and no oil, I think it would work well. It's hot enough.

The oil is mostly to keep dust down when filling hoppers on coal furnaces in homes. Stokermatic/Firetender or combustioneer furnaces are commonly in living areas of homes and without oil, coal dust would get everywhere.
Do you know what the Btu is for that coal? I'm guessing it would be in the range of 11.5-13K Btu...?

I don't know the BTUs, but it's up there with anthracite just by the fact that I can't get my hand near it, just like anthracite. The Wyoming and Alaskan coal was like a wood fire, where I could stick my hand almost into the flames.

stoker-man, those are not clinkers, they are pieces of coke - coal that swells and distills its volitiles and leaves behind porous carbon and ash. I have yet to see any clinkers in any of the tests thus far; clinkers are melted and fused ash- the only thing i've found close to a clinker are the crusty bits on the ash ring of the alaska coal.

OK, I stand corrected on the clinker issue. I'm trying to get some Kentucky coal, but don't know how to get it.

is that a hint? I would send you some, but unfortunately i'm completely out of kentucky stoker; i have a few ton blend of 50/50 kentucky and ohio pea stoker that I use with much success, but w/out trying straight KY coal, you won't know how hot and nice it burns. I could send you some of the blend to try: PM me with the shipping information.