A study of slagging and fouling: Current theory and experimental characterisation of deposits

Anthony De Girolamo, Bai Qian Dai, Xiaojiang Wu, Lian Zhang

Research output: Chapter in Book/Report/Conference proceedingConference PaperOther


This paper will present an extensive review of current theory and practical considerations affecting fouling and slagging, as well as an experimental study on the characterisation of ash deposits collected from a pulverised lignite-fired 150t/h steam industrial boiler. With the depletion of high-rank coals and petroleum, the use of low-rank coal such as Victorian brown coal, rich in moisture, alkali and alkaline earth metals (Na, K, Ca and Mg), has been receiving increased attention in the energy and mining industries. Low-rank brown coal has large reserves in both Australia and China, and also other parts of the world. It is estimated that fouling and slagging related issues cost the global utility industry several billion dollars annually due to reduced heat transfer and equipment maintenance. In particular, brown coal or lignite may have increased tendencies for fouling due to its higher sodium content than bituminous coals. The analysis on ash deposits was conducted on samples collected at various locations in the industrial boiler using X-ray Diffraction (XRD), X-ray fluorescence (XRF) spectroscopy and a computer controlled scanning electron microscope (CCSEM). This serves to identify the roles of different chemicals in slagging and fouling. The results revealed the dependency of certain chemicals to initiate a primary deposit on boiler surfaces including walls of the combustion zone and superheater tubes that is highly sticky having the capability to trap fine ash particulates. The nature of these chemicals was conditional upon the location within the boiler.

Original languageEnglish
Title of host publication30th Annual International Pittsburgh Coal Conference 2013, PCC 2013
Subtitle of host publicationBeijing, China; 15-18 September 2013
Place of PublicationPittsburgh, Pennsylvania, USA
PublisherInternational Pittsburgh Coal Conference
Number of pages7
ISBN (Print)9781629934389
Publication statusPublished - 2013
Event30th Annual International Pittsburgh Coal Conference 2013, PCC 2013 - Beijing, China
Duration: 15 Sep 201318 Sep 2013


Conference30th Annual International Pittsburgh Coal Conference 2013, PCC 2013


  • Additives
  • Fouling
  • Lignite
  • Slagging

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