Hehehe, uh thx, Lucky? The fires I use professionally are more than hot enough to melt the irons I put in (been using them roughly 14 years). The "clinker" I've noted, simply demonstrates various characteristics based on the location from where it came (not on temperature of fire). This is after using about 6 tons of Elk Valley Coal, 1 ton of British Coal, 1/2 ton of Pennsylvania Coal. Now warrant that it wouldn't be specific to a country, but more likely, the mine from where it is extracted (in the case of the British and Penn coal, maybe even the seam---since the sampling wasn't large enough nor at different extraction times). The British coal I was using, was from a variety of samples from a 40' shipping container full (but even that would only account for a small fraction of a single seam). I've seen no difference between the coals using a variety of formats from coal dust (with about 5% fines) to 3/4"-1" chunks, assisted with water or not, nor using pre-coked coal or not.....the outcome of the clinker seems to have similar characteristics I'd mentioned earlier.
Yes, that's what i'm finding out! I'd like to get samples of coal to test from Australia as well, just to see how its' clinker form.