Anthracite Mohs scale), its higher relative density of 1.3–1.4, and luster, which is often semi-metallic with a mildly brown reflection. It contains a high percentage of fixed carbon and a low percentage of volatile matter. It is also free from included soft or fibrous notches and does not soil the fingers when rubbed. Anthracitization is the transformation of bituminous coal into anthracite. The moisture content of fresh-mined anthracite generally is less than 15 percent. The heat content of anthracite ranges from 22 to 28 million Btu per short ton (26 to 33 MJ/kg) on a moist, mineral-matter-free basis. The heat content
Pulverized coal-fired boiler limited extent, in steam locomotives. For example, see Prussian G 12. In 1929 the United States Shipping Board evaluated a pulverized coal-boiler on the "Mercer", a 9,500 ton merchant ship. According to their report the Mercer with its pulverized coal-boiler ran at 95% efficiency of its best oil fuelled journey. It was cheaper to operate and install than ship's boilers using oil as fuel. Pulverized coal-fired boiler A pulverized coal-fired boiler is an industrial or utility boiler that generates thermal energy by burning pulverized coal (also known as powdered coal or coal dust since it is as fine as face