Anthracite latter in two or three sizes, all three being above in (38 mm) size on round-hole screens. High grade (HG) and ultra high grade (UHG) anthracite are the highest grades of anthracite coal. They are the purest forms of coal, having the highest degree of coalification, the highest carbon count and energy content and the fewest impurities (moisture, ash and volatiles). High grade and ultra high grade anthracite are harder than standard grade anthracite, and have a higher relative density. An example of a chemical formula for high-grade anthracite would be CHONS, representing 94% carbon. UHG anthracite typically has a
Anthracite iron and received it in 1837. By the time the patent was sealed, Yniscedwyn was producing about 35 tons of iron using anthracite only as a fuel. Inspired both by Geisenhainer and Crane (whose success was closely followed by the LC&N), experiments in the US continued. Baughman, Guiteau and Company used an old furnace near Mauch Chunk to produce some anthracite iron during late 1837. They built another experimental furnace nearby, which was worked for about two months during fall and winter 1838 and for some time in 1839, but mechanical deficiencies led them to abandon the furnace at the end