Coals are heterogeneous, complex and noncrystalline macromolecules containing both organic and inorganic materials. Inorganic materials of coal contain a number of inorganic constituents, especially sulfur, which plays an important role in almost all coal utilization systems. Some techniques have been applied to coal to remove its inorganic materials from the organic part. One of the most suitable methods is froth flotation for removal of pyritic sulfur from coal. By this method, high sulfur removal from lignite was possible. Alkali desulfurization and oxidesulfurization also are effective applicable methods for high sulfur coals. (C) 2002 Elsevier Science Ltd. All rights reserved.