Combustion technologies using coal-water suspensions create a number of new possibilities for organising combustion processes so that they fulfil contemporary requirements (e.g., in terms of the environment protection-related issues). Therefore, an in-depth analysis is necessary for examining the technical applications of coal in the form of a suspension as a fuel. The paper undertakes the complex study of coal-water suspension combustion in air and in the fluidised beds. This, according to the author, best simulates the conditions that should be satisfied in order to use the new "fuel'' efficiently and ecologically. An important element of the study was the identification of coal-water suspension drops, its complex morphology and evolution in the combustion process. The mathematical model enables the prognosis for change of the surface and the centre temperatures and a mass loss of the coal-water suspension during combustion in air and in the fluidised bed. (C) 2010 Elsevier Ltd. All rights reserved.