lsayre wrote:Can you make any valid determination of the quality of anthracite merely by looking at it? And if so, what qualities do you look for?
You can judge how well it is processed
by the size uniformity, and lack of fines/foreign material...but you really need to burn it to judge the btu and ash content. One thing I have noticed, anthracite that has a really glossy appearance tends to be harder, and may require an air adjustment to burn properly in an underfed or inclined bed stoker.
Why don't you just switch to the Stockton coal to see if you notice any difference in the boiler operation?