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
Carbon fibers carbon fibers. A 1970 joint technology agreement allowed Union Carbide to manufacture the Japan’s Toray Industries product. Morganite decided that carbon-fiber production was peripheral to its core business, leaving Courtaulds as the only big UK manufacturer. Courtelle's water-based inorganic process made the product susceptible to impurities that did not affect the organic process used by other carbon-fiber manufacturers, leading Courtaulds ceasing carbon-fiber production in 1991. During the 1960s, experimental work to find alternative raw materials led to the introduction of carbon fibers made from a petroleum pitch derived from oil processing. These fibers contained about 85% carbon and had excellent