Improved Ash Fusion Test

A new method of the measurement of Ash Fusion Temperatures has been developed using essentially the same equipment as is used for the 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 the progressive change during melting of the ash. Further, the new method has a much improved precision in determination of the temperatures at which these changes take place. Both the repeatability and reproducibility of the results are excellent and might be further improved by continuous video recording.

The correspondence between the index points of AS1038.15 (Initial Deformation, Sphere, Hemisphere and Flow) is poor with some IDs being identified at temperatures which in the new test produced no movement at all.

The temperatures of significant movement in the new test do appear to be systematic and 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.

The cost of conducting the new test, which uses essentially the same equipment as the AS1038.15 Ash Fusion test, should be less than twice the current cost but with far more information being available.