This Chapter reviews the characteristics, and utilisation and disposal options for the residues generated from coal combustion. Until fairly recently these residues, consisting mainly of ash of various types, were usually considered to be waste products. However, over the past 20 years there has been an increasing appreciation of the potential of coal-use residues as usable products in their own right, and a considerable amount of research has been undertaken into potential markets for these materials. Some, such as fly ash from conventional pulverised coal combustion, have already become well-established, principally in construction-industry applications
