Coal Preparation

Small Coal Washability by Water Fluidisation

Coal Preparation » Fine Coal

Published: July 02Project Number: C10050

Get ReportAuthor: Kevin Glavin | TUNRA, University of Newcastle

Galvin and Pratten (1999) have previously reported the technique of utilizing the density segregation effect of a narrow size range of particles in a fluidised bed to determine washability data. This has been verified with replication of yield density information, but to date there has been no investigation of the performance of the method in generating yield-ash distributions. This project examines the procedure of using water fluidisation for attaining coal washability data with a view to providing a rapid, accurate and safe alternative to the current laboratory method of float-sink testing.

In this study, the primary focus has been on using water fluidisation to obtain data for the particle size range of -4.0+0.25mm. We have identified that separation is a combination of the techniques of fluidisation and particle sizing. This study has shown that the segregation of particles is independent of whether the material is initially sized into narrow particle size ranges for fluidising or if a broad size range is fluidised and then the subsamples sized into individual fractions for analysis. This second option allows a simplification of the analytical technique for obtaining washability data by water fluidisation.

The new method has been tested using a variety of Australian coals. Results indicate good agreement between the particle density distribution data generated by float-sink testing and the new method, although, comparison of particle ash distribution information shows obvious variation mainly in the low ash region. This was especially true for one of the coals tested, which we conclude was atypical. This deviation is due to particle dispersion, which is an integral part of the fluidisation process and cannot be entirely eliminated. The application of a universal correction factor to washability information generated by the new method has been employed to effectively remove any discrepancy with float-sink data.

Although it is desirable to minimise any discrepancy between results produced by floatsink testing and the new method, the wash column data may in fact be an indication of the optimal performance of a particular coal under autogenous separation conditions, similar to jigs, teetered bed separators and spirals processing. The difference may represent the true coal washability performance characteristics that can be expected from a normal plant processing environment, in the same way the tree curve characterises optimum flotation performance.

The major advantage of the new water-based fluidisation technique is the significant reduction in the use of heavy organic liquids utilised in the float-sink procedure, and hence considerable health and environmental benefits. The new method also provides information on a size-by-size basis. Finally, application of the new method to fine particles (-0.250 +0.045mm) has also produced results comparable to the standard laboratory technique of tree flotation.


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