ABSTRACT
The initial stages of pulverised fuel ash deposit formation are greatly influenced by the surface chemistry of individuai ash particies. In this work, small area and imaging x-ray photoelectron spectroscopy, together with argon ion etching, have been used to investigate the surface and sub surface composition and chemistry of individual pulverised fuel ash particles from Bentinck coal used in Ratcliffe Power Station, Unit 3. X-ray photoeiectron images have been recorded from areas containing many particles. The images obtained not only highlighted the individual particles against the background of the sample stub but have also been used to indicate those particles with unusual surface composition. Individual particle surface chemistries will play an important role in determining the propensity for adhesion of the particles, either with a clean substrate, each other or an already formed ash deposit. The elemental and chemical state information obtained during these two studies of the individual particles agreed well with previous studies using the same technique. However, this is the first time that it has been possible to analyse the chemistry of individual ash particles without recourse to average results given by conventional large area measurement.
