Years ago, my company did a characterization analysis of some 20 or 30 different types of coal, from hard to soft and labeled as to what mine and in some cases, what shaft. It's all pulverized (dust) coal. It was made especially for the analysis, so, it's probably clean stuff. We still have 20 or 30 55 gallon drums of it, and I could probably dig out the research if anyone is interested
Free for the asking.
