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
Carbon monoxide assigned to carbon. In this count, carbon then has only two valence electrons in the molecule compared to four in the free atom. Carbon monoxide poisoning is the most common type of fatal air poisoning in many countries. Carbon monoxide is colorless, odorless, and tasteless, but highly toxic. It combines with hemoglobin to produce carboxyhemoglobin, which usurps the space in hemoglobin that normally carries oxygen, but is ineffective for delivering oxygen to bodily tissues. Concentrations as low as 667 ppm may cause up to 50% of the body's hemoglobin to convert to carboxyhemoglobin. A level of 50% carboxyhemoglobin may result