Coal breaker the United States in the state of Pennsylvania (where, between 1800 and the mid-20th century, many of the world's known anthracite reserves were located). At least one source claims that, in 1873, coal breaking plants were found only at anthracite mines in Pennsylvania. The first function of a coal breaker is to break coal into pieces and sort these pieces into categories of nearly uniform size, a process known as breaking. The second function of a coal breaker is to remove impurities (such as slate or rock), and then grade the coal on the basis of the percent of impurities
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