Coal quality this fall

I've been modifing my stoker system blower and trying to tune up my combustion, it has started to burn real good and hot, making a very desirable clinker for my situation.
I was proud of my solutions with the help of this forum.
Yesterday while at work I heard a story about a converstion by a power plant operator and a coal miner. The story went like this, "the coal you are supplying is burning great", " yes we are behind on removing overburden from the low grade coal that we mix with the high grade, to achive the 7,250 btu/lb, so our coal is currently around 8,000 btu/lb".
Not sure of the facts but my burner is working great, anyone else experiancing this?

I would go ahead and stock up! It's not uncommon for mining companies to blend two seams of coal when they're stripping it already - they will typically blend them to get a decent AND economical product.