Interesting article. However it would seem, unless you're hell bent to use anthracite, using real charcoal would be more reliable. It is naturally low sulfur. Or you could build a coking furnace to make coke from either anthracite or bituminous. In blacksmithing you have to coke the coal (like making charcoal from wood) in order to get enough heat to melt steel. It is pretty easy to get to temperature with coke or charcoal.