This is my first year with coal, I started out by burning a dozen bags of blashek, no problems. Picked up a half ton of no name, store bagged from a local supplier, seemed to burn the same as the blashek. So I ordered 6 tons more. I just had it delivered last weekend, and am on my second bag. I notice I seem to get a yellow-blue flame out of this coal, as opposed to the nice blue flames I was getting from the last load. It also seems to be a lot dustier, with (so far) a few pieces of wood per bag. Any idea what could be giving me the yellow-blue flame, and is it anything I should be concerned about?