An Improved Ash Fusion Test

  • Charles D. A. Coin
  • Hakan Kahraman
  • Adrian P. Peifenstein


A new method of measurement of ash fusion temperatures has been developed using essentially the same equipment as is used for measurement of ash fusibility under Standards such as AS1038.15–87 and ASTM D1857–87. However, unlike the standard method the new method produces quantitative results of progressive dimensional changes during heating and melting of the ash. Further, the new method has much improved precision in determination of the temperatures at which these changes take place. Repeatability and reproducibility of the results are much improved and have scope for further improvement. Correspondence between the index points of current ash fusion tests [Initial Deformation, Sphere, Hemisphere and Flow] with reference points in the new method is poor, particularly in relation to ID temperatures and initial dimensional changes. The temperatures of significant movement in the new test appear to be systematic and therefore are likely to correspond to mineralogical melting points. As slagging and fouling mechanisms depend on relative melting of mineral phases, the new test should provide a significant improvement on the current ash-fusion method.


Significant Movement Narrow Temperature Range Initial Deformation Extended Temperature Range Electrical Conductance Method 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. AS 1038.15 (1987). “Methods for the analysis and testing of coal and coke - fusibility of higher rank coal ash and coke ash”. Australian Standards Association.Google Scholar
  2. ASTM D1857–87 (1987). “Standard test method for fusibility of coal and coke ash”. American Society for Testing and Materials.Google Scholar
  3. Australian Coal Report (1994). “Coal 1994”. Published by Australian Coal Report, Sydney, 168.Google Scholar
  4. BS 1016, Part 15 (1970). “Fusibility of Coal Ash and Coke Ash”. British Standard.Google Scholar
  5. Coin C.D.A., Kahraman H. & Reifenstein A.P. (1994). “Improved Ash Fusion Test”. Australian Coal Association Research Project 3092, 54.Google Scholar
  6. Conn R.E. and Austin L.G. (1984). “Studies of sintering of coal ash relevant to pulverised coal utility boilers. 1:Examination of the Raask shrinkage-electrical resistance method”. Fuel, 63, 1664.Google Scholar
  7. Creelman, R.A. (1994). “Using mineralogy as a guide to understanding slagging: a case study”. In proceedings of Practical Workshop on Impact of Coal Quality on Power Plant Performance, May 15–18, Brisbane, Paper 14, 12.Google Scholar
  8. Cumming I.W., Joyce W.I. and Kyle J.H. (1985). “Advanced techniques for the assessment of slagging and fouling propensity in pulverised coal fired boiler plant” J. Inst. E ., 58.Google Scholar
  9. Cumming I.W. and Sanyal A. (1981). “An electrical conductance method for predicting the onset of fusion in coal ash”. Proceedings of the Engineering Foundation Conference, 12–17 July, Henniker, New Hampshire. Richard W Bryers (Ed), 1983, Engineering Foundation.Google Scholar
  10. DIN 51730 (1984). “Determination of Fusibility of Fuel Ash”. German Standard.Google Scholar
  11. Ellis G.C., Ledger R.C. and Ottrey A.L. (1987). “Thermo-mechanical analysis as a technique for characterisation of ashes and deposits formed during combustion”. Steaming coal testing and characterisation workshop, Institute of Coal Research, Univ. of Newcastle, NSW, Australia, 1987, 17.Google Scholar
  12. GE 219–74. “Coal Ash Fusibility Determination Method”. Peoples’ Republic of China National Standard.Google Scholar
  13. Gerald P.H., Huggins F.E. and Dunmyre G.R. (1981). “Investigation of the high-temperature behaviour of coal ash in reducing and oxidising atmospheres”. Fuel, 60, 585.Google Scholar
  14. Gibson J.R. and Livingston W.R. (1991). “The sintering and fusion of bituminous coal ashes”. Engineering Foundation Conference on Inorganic Transformations and Ash Deposition During Combustion, Palm Coast, Florida, 425–447.Google Scholar
  15. GOST 2057 (1982). “Methods of Determining Ash Fusibility”. State Standard of the USSR.Google Scholar
  16. Gray V.R. (1987). “Prediction of ash fusion temperatures from ash composition for some New Zealand coals”. Fuel, 66, 1230.Google Scholar
  17. Hough, D.C. (1990). “ASME Ash Fusion Research Project”. Amer. Soc Mech. Eng. Report No. FT/88/01, 7.Google Scholar
  18. Huggins F.E., Deborah A.K. and Gerald P.H. (1981). “Correlation between ash-fusion temperatures and ternary equilibrium phase diagrams”. Fuel, 60, 577.Google Scholar
  19. ISO 540 (1981). “Determination of Fusibility of Ash”. International Standard Organisation.Google Scholar
  20. Lloyd W.G., Riley J.T., Risen M.A., Gilleland S.R. and Tibbitts R.L. (1989)a. “Estimation of ash softening temperatures using cross terms and partial factor analysis”. Energy & Fuels, 4, 360.Google Scholar
  21. Lloyd W.G., Riley J.T., Risen M.A., Gilleland S.R. and Tibbitts R.L. (1989)b. “Estimation of ash fusion temperatures from elemental composition: a strategy for regressor selection”. Amer. Chem. Soc. Divn. Fuel Chem. Preprints, 36, 325.Google Scholar
  22. Lloyd W.G., Riley J.T., Risen M.A., Gilleland S.R. and Tibbitts R.L. (1993). “Estimation of ash fusion temperatures”. J. Coal Quality,12(1), 30–36.Google Scholar
  23. Queensland Coal Board (1990). “Queensland coals: physical and chemical properties, colliery and company information”. 8th Edition. Published by The Queensland Coal Board, Brisbane.Google Scholar
  24. Raask E. J. (1979). “Sintering characteristics of coal ashes by simultaneous dilatometry-electrical conductance measurements”. J. Thermal Analysis, 16, 91.Google Scholar
  25. Rees O.W. (1964). “Composition of the ash of Illinois coals”. Illinois State Geological Survey, Urbana, Circular 386.Google Scholar
  26. Riley J.T., Lloyd W.G., Risen M.A., Gilleland S.R. and Tibbitts R.L. (1989). “Predicting ash fusion temperatures from elemental analysis”. In Proceedings of the 6th International Coal Testing Conference, 1989, 58.Google Scholar
  27. SABS Method 932. “Fusibility of Coal Ash”. South African Bureau of Standards.Google Scholar
  28. Sanyal A and Cumming I.W. (1981). “An electrical resistivity method for detecting the onset of fusion in coal ash”. US Engineering Foundation Conference on Slagging and Fouling from Combustion Gases, Henniker, 329–341.Google Scholar
  29. Sanyal A. and Mehta A.K. (1993). “Development of an electrical resistance method based on ash fusion test”. Engineering Foundation Conference on Impact of Ash Deposition on Coal Fired Plant, June 20–25, Sollihul, England.Google Scholar
  30. Steiger W.A., Singletary J.H. and Kohut J.F. (1988). “Application of a microcomputer to the determination of coal ash fusibility characteristics”. J. Coal Quality, 7, 48.Google Scholar
  31. Sondreal E.A and Ellman R.C. (1975). “Fusibility of ash from lignite and its correlation with ash composition”, U.S. Bureau of Mines Rept., GFREC/RI-75–1, Pittsburgh.Google Scholar
  32. Vorres K.W. (1979). “Effect of composition on melting behaviour of coal ash”. J. Eng. Power, 101, 497.Google Scholar
  33. Wall T.F., Gupta R.P., Polychroniadis P., Ellis G.C., Ledger R.C. and Lindner E.R. (1989). “The strength, sintering, electrical conductance and chemical character of coal ash deposits”, NERDDC Project No. 1181 - Final Report, Vol. 1, Summary Report.Google Scholar
  34. Winegartner E.C. and Rhodes B.T. (1975). “An empirical study of the relation of chemical properties to ash fusion temperatures”. J. Eng. Power, 97, 395.Google Scholar

Copyright information

© Springer Science+Business Media New York 1996

Authors and Affiliations

  • Charles D. A. Coin
    • 1
  • Hakan Kahraman
    • 1
  • Adrian P. Peifenstein
    • 1
  1. 1.ACIRL Ltd.BoovalAustralia

Personalised recommendations