Technical Market Support

Practical Application of the Improved Ash Fusion Test

Technical Market Support » Thermal Coal

Published: January 99Project Number: C5057

Get ReportAuthor: H Kahraman, Adrian Reifenstein, Charles Coin | ACIRL Ltd, University of Queensland

The main objective of the present report is to investigate the practical applicability of the Improved Ash Fusion Test for a suite of selected coals that were previously investigated in ACARP Project C3097 Evaluate Combustion Behaviour of Australian Export and Overseas Low Rank Coal Blends.

The issue was to relate the results from the Improved Ash Fusion Test (which are provided as a continuous record of shrinkage against temperature) to plant performances from the combustion testing and if possible, existing ash fusion temperatures.

The shrinkage traces have been explained in terms of events of liquid formation at the temperatures predicted by phase diagrams and are related to the ash chemistry. There is only very poor correlation between the Improved Ash Fusion Test results and the standard ash fusion test results. The extreme subjectivity of many of the standard ash fusion test results makes comparison meaningless. It is demonstrated that the standard ash fusion test results do not discriminate effectively between the ashes in this study, whereas the Improved Ash Fusion Test produces an evaluation that is equal to or perhaps better than the visual and tactile evaluation of the ash on the slagging panels in the Boiler Simulation Furnace.

The Improved Ash Fusion Test demonstrated that it would be useful to rank the coals in terms of their performance for slagging when compared against operating power plant data. The test successfully predicted the troublesome coals in the combustion testing.

Although the Improved Ash Fusion Test is much closer to a correlation with the practical outcomes in the Boiler Simulation Furnace it is still necessarily imperfect. It does not take into account the time frame with which reactions take place in commercial Pulverised Fuel fired boilers. It also does not take into account the continuously variable conditions experienced in the turbulent combustion volume and on the slagging surfaces.

The standard ash fusion test is highly subjective and there is little scope of improving that subjectivity either through computerisation or training. Also the standard ash fusion test lacks some crucial details which are evident in the Improved Ash Fusion Test.

As the Improved Ash Fusion Test slagging index appears to do just as well as the qualitative Combustion Test Slagging Index and with much better than the Improved Ash Fusion Test which showed no correlation at all, then its recommendation seems quite warranted.

The corollary derived from this study is that as the standard ash fusion test continues to give no meaningful results, then it should be phased out of use.


Health and safety, productivity and environment initiatives.


Open Cut

Safety, productivity and the right to operate are priorities for open cut mine research.

Recently Completed Projects

C19024Establishing Ecologically Sustainable Mine Water Release Criteria In Seasonally Flowing Streams

Extreme rainfall conditions in the Fitzroy Catchment over an approxi...

C25030Coal Mine Open Pit Final Void Closure And Relinquishment - Addressing Uncertainty In Coal Mine Environmental Planning

This report addresses uncertainties faced by coal mine operators whe...

C27046Estimation Of True Deformation Vector From Slope Radar Monitoring

Slope deformation radar monitors are now widely used in open cut coa...

Open Cut

Coal Preparation

Maximising throughput and yield while minimising costs and emissions.

Recently Completed Projects

C27004Improving Coal Flotation With Oscillatory Air Supply

This report provides detailed information on coal flotation with os...

C25018Improving Solids Recovery And Moisture Reduction In Ultrafine Coal Dewatering

This report provides detailed information on fine coal dewatering in...

C27028Lab Froth Flotation Testing Guide With Coal Quality

Correct outcomes from laboratory froth flotation testing in coal bor...

Coal Preparation

Technical Market Support

Market acceptance and emphasising the advantages of Australian coals.

Recently Completed Projects

C26039Nanoporosity In Cokes: Their Origin, Control And Influence On CO2 Reactivity

This project using the outcomes of previous project C24060, examine...

C28063A Comprehensive Technical Review Of High-Efficiency Low-Emission (HELE) Pulverised Coal Combustion Technologies For Power Generation

Research and development has been undertaken worldwide to realise co...

C28064Carbon Structure Transformation During Coking Of Australian Coking Coals: Better Understanding The Coke Formation

Carbon structures of coke that are formed during the plastic layer a...

Technical Market Support

Mine Site Greenhouse Gas Mitigation

Mitigating greenhouse gas emissions from the production of coal.

Recently Completed Projects

C28076Selective Absorption Of Methane By Ionic Liquids (SAMIL) - Phase 2 Demonstration In A Packed Bed Reactor

An alternative approach to high temperature oxidation of ventilation...

C26004CFD Modelling Of Reverse Thermal Oxidisers For VAM Abatement - CFD Modelling Of Fixed-Bed RTO Devices

The project is part of a larger multi‐phase program of study a...

C27058Technological Assessment Of A Recycle Reactor For VAM Abatement

Underground coal mining emits high volumes of methane, diluted in ve...

Mine Site Greenhouse Gas Mitigation

Low Emission Coal Use

Step-change technologies aimed at reducing greenhouse gas emissions.

Recently Completed Projects

C17060BGasification Of Australian Coals

Four Australian coals were trialled in the Siemens 5 MWth pilot scale ga...

C17060AOxyfuel Technology For Carbon Capture And Storage Critical Clean Coal Technology - Interim Support

The status of oxy-fuel technology for first-generation plant is indicate...

C18007Review Of Underground Coal Gasification

This report consists of a broad review of underground coal gasification,...

Low Emission Coal Use

Mining And The Community

The relationship between mines and the local community.

Recently Completed Projects

C16027Assessing Housing And Labour Market Impacts Of Mining Developments In Bowen Basin Communities

The focus of this ACARP-funded project has been to identify a number...

C22029Understanding And Managing Cumulative Impacts Of Coal Mining And Other Land Uses In Regions With Diversified Economies

The coal industry operates in the context of competing land-uses that sh...

C23016Approval And Planning Assessment Of Black Coal Mines In NSW And Qld: A Review Of Economic Assessment Techniques

This reports on issues surrounding economic assessment and analysis ...

Mining And The Community


National Energy Research,Development & Demonstration Council (NERDDC) reports - pre 1992.

Recently Completed Projects

1609-C1609Self Heating of Spoil Piles from Open Cut Coal Mines

Self Heating of Spoil Piles from Open Cut Coal Mines

1301-C1301Stress Control Methods for Optimised Development...

Stress Control Methods for Optimised Development and Extraction Operations

0033-C1356Commissioned Report: Australian Thermal Coals...

Commissioned Report: Australian Thermal Coals - An Industry Handbook