REMOVAL OF MINERAL MATTER FROM ANTHRACITE BY CHLORINATION AT HIGH TEMPERATURES

Special Research Report SR-12 St. Nicholas anthracite containing 7. 61% mineral matter as ash was ground to a mesh size of 42 x 65 and treated for one hour with chlorine at ' temperatures of 7 25, 800, 1000, 1200, and 1400°C. This treatment resulted in a marked decrease in the ash content of the anthracite, with a maximum removal of about 80.Yo at chlorination temperatures above 1000°C. Increasing the chlorination time (at 1200°C.) to six hours removed about 90% of the ash. Anthracite exposed to the same temperatures in inert gas instead of chlorine showed no reduction in ash. In addition, chlorine treatment caused significant changes in electrical resistivity {a qecrease with increasing treatment temperature) and surface areas. These changes are discussed in the text. It was also found that activation of the anthracite prior to chlorination helped somewhat in removing more ash.