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
Black carbon used by developed countries, such as clean diesel and clean coal, could be transferred to developing countries to reduce their emissions. Black carbon emissions are highest in and around major source regions. This results in regional hotspots of atmospheric solar heating due to black carbon. Hotspot areas include: Approximately three billion people live in these hotspots. Approximately 20% of black carbon is emitted from burning biofuels, 40% from fossil fuels, and 40% from open biomass burning. Similar estimates of the sources of black carbon emissions are as follows: Black carbon sources vary by region. For example, the majority of soot