I think it may be an incompatibility with CraftTweaker. So in the pack I play there's a script that unifies all metals under a certain priority. Thermal foundation is the highest. I've notices that in the recipes for the blast furnace, it doesn't abide by the priority. This is messing up other smelting recipes it seems. From what I can tell, the smelting recipes the blast furnace adds don't look very efficient. I'm not an expert but I feel like it could be a much better system. Instead of having many recipes for each ore, use oredict? All I know is that when I smelt mekanism steel dust, for some reason it smelts into mekanism steel which isn't right. I am also on the current version of the mod.