Thermal analysis of coal ash

Abstract

Carbon materials are widely used in metallurgy and in the power industry as fuels and reducing agents. Coal, although inexpensive, is difficult to use, on account of its high ash content. In the operation of industrial systems, the ash might melt, with the subsequent formation of buildup. In addition, coal ash must be stored in tailings. Therefore, fuel oil and natural gas are more commonly used. Ash tailings pose a significant environmental problem in Russia. Various methods are known for the use of ash in construction. However, their adoption has been slow, on account of the complications caused by the variability in ash composition and properties. The industrial applicability of ash may be assessed by studying the physicochemical processes that accompany ash heating and determining the relation between the properties and mineral composition of ash. An important property of ash is its fusibility, which may vary widely on account of its nonuniform mineral composition. Traditionally, the fusibility of ash is determined on the basis of State Standard GOST 32978–2014 (ISO 540:2008). As in any visual method, the results are highly inaccurate. Existing theoretical analyses employ fusibility values obtained on the basis of the international standard. In this context, there is a pressing need to develop and test new methods of determining the melting point of ash.