Coal Preparation

Leveraging Detailed Maceral Component Information from CGA

Coal Preparation » Fine Coal

Published: May 18Project Number: C25017

Get ReportAuthor: Bruce Atkinson | QCC Resources Pty Ltd

Since Project C18041 was completed, the CSIRO image analysis software has been transitioned and more detailed information is able be generated by further extending and re-coding the software calculations. This allows previous images to be re-analysed to extract additional information of tremendous value to coal characterisation, washability and liberation behaviour.

Liberation information will be critical to the future development of the coal industry. New commercial forms of thermal coal utilisation need to be developed, and the reality of ultraclean coal is likely to be pivotal. CGA offers immense benefits for the purpose of characterising coals and their potential beneficiation routes.

It was however evident that further development of the image analysis software was necessary to determine component maceral and mineral size (within each grain/particle), for each grain type. Such development has facilitated a more fundamental characterisation of the components in each particle size and grain class, and consequently provides direct information as to any liberation potential from any specific particle sizes.

This project focussed on composite grains defined as '-rich' (less than 65% of any one component) or '-dominant' (65-95% of any one component) in the CGA classifications.

In respect of the potential to liberate coal material from mineral matter, the Sinks 1.40 RD fractions were investigated.

In respect of the potential to liberate mineral matter from coal matter, the Floats 1.80 RD fractions were investigated.

This project has found that, for the three coals investigated:

  • Mineral matter is generally very finely disseminated in composite coal grains, such that fine grinding to smaller than 0.125 mm would be required in order to start to liberate significant mineral.
  • Composite dark mineral predominates in the minus 0.038 mm particle size fraction, with its major component in the minus 0.008 mm fraction.
  • Composite vitrinite and inertinite occur mainly in the minus 0.50 plus 0.063 mm particle size fractions.
  • Component mass distribution relative to particle (grain) size is not materially different to component mass distribution relative to the component size itself.
  • Different coals exhibit subtle differences as to how the composite components are distributed.
  • A Liberation Index has been defined whereby the numerical value of the Index directly provides the mass of pure component which may be expected to be liberated at a given size.
  • The image analysis software has been augmented to enable the particle surface composition to be quantified. The option to procure particle surface composition will be invaluable to fine coal processes such as flotation, coagulation and flocculation.


Health and safety, productivity and environment initiatives.

Recently Completed Projects

C26061The Young’S Moduli, Poisson’S Ratios And Poroelastic Coefficients Of Coals

This report describes the measurement of coal (and rock) properties ...

C24015 Assessment Of Convergence Based Roof Support Design For Longwall Abutment Loads

The aim of Stage two of project C24015 was to develop a roof support...

C25072New Approaches To Mine Gas Analysis And Ratios

The spontaneous combustion of coal remains a hazard in underground c...


Open Cut

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

Recently Completed Projects

C26022Real-Time Prediction Of Coal Top Through Guided Borehole Radar Wave Imaging For Open Cut Blast-Hole Drilling

Damage to the tops of coal seams caused by incorrect blast stand-off...

C26027Using An Ecotoxicological Approach To Validate The DGT Technique For The Measurement Of Bioavailable Metal Concentrations

This project builds on the opportunity identified through Project C2...

C25039Prediction Of Long-Term Salt Generation From Coal Spoils

The release of salts from spoil piles has the potential to affect su...

Open Cut

Coal Preparation

Maximising throughput and yield while minimising costs and emissions.

Recently Completed Projects

C250083D Flotation Of Fine Particles

In this project a process for the continuous, selective agglomeratio...

C20052Full Scale Gravity - Desliming Using Cascading REFLUX Classifiers

Considerable quantities of fine coal are disposed of as part of the ...

C26007 Revised Dustiness And DEM Test Method (Update Of AS4156.6) Part 2:Preparation

In 2015 project C23054 investigated and reviewed the Australian Stan...

Coal Preparation

Technical Market Support

Market acceptance and emphasising the advantages of Australian coals.

Recently Completed Projects

C25045Stage Two - Assessment Of In Situ High-Temperature Strength Of Cokes

Stage I of this project established a reliable and repeatable proces...

C27003Review Of ACARP Research To Support Marketing Of Australian Thermal Coal

In this project, researchers pinpointed issues relating to the use o...

C25044Trace Elements In Coal; Status Of Test Methods In Use And Their Applicability


The key objectives of this stage...

Technical Market Support

Mine Site Greenhouse Gas Mitigation

Mitigating greenhouse gas emissions from the production of coal.

Recently Completed Projects

C27008Selective Absorption Of Methane By Ionic Liquids

The connection of a ventilation air methane (VAM) abatement plant di...

C24061Proof-Of-Concept Photocatalytic Destruction Of Methane For Coal Mining Fugitive Emissions Abatement

Australia's fugitive emissions in 2015 were 41 Mt CO2-e (representin...

C23052Novel Stone Dust Looping Process For Ventilation Air Methane Abatement - Phase 3

This multi‐phase project is concerned with the mitigation of m...

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