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
Calgon Carbon pond and aquarium cleaning, and removal of impurities during the manufacturing process of vitamins. The company also serves "industrial processes" applications such as liquid chemicals, catalyst support, gas and water processing, ultrapure water, and bio-based chemicals. Activated carbon, which is a small form of carbon with a large pore structure that can remove impurities, was one of the first products produced by the company in the 1940s. Initially manufacturing granular activated carbon (GAC), the company also began producing forms such as powdered, pellets, and later cloth. Pittsburgh Coke and Chemical introduced an early activated carbon system to decolorize sugar in