Coal Preparation

Adaptation of Coal Grain Analysis to Improve Flotation Yield Estimation

Coal Preparation » Fine Coal

Published: October 19Project Number: C25019

Get ReportAuthor: Bruce Atkinson | QCC Resources

This project involved sampling of full-scale flotation circuits at each of six different coal preparation plants, each subject to three different reagent dose rate regimes (three sampling runs per site). Coal Grain Analysis (CGA) was undertaken on feed, concentrate and tailing for each run. This project was an extension of an earlier project C24045, where three different sites had been previously investigated in the same manner. This project incorporates the data from C24045 and encompasses all nine sites.

The primary objectives of this project were to:

  • Employ CGA to characterise the flotation response at a particulate level;
  • Compare the CGA data and CPP flotation circuit performance to laboratory sequential (tree) flotation and fine float and sink test tests on each flotation feed; and to
  • Evaluate CGA as a means to model flotation in a more reliable manner, in order to facilitate improved flotation yield estimation.

The key findings of this project include:

  • Characterising flotation response at a particulate level, in terms of maceral and mineral group response, provides deep insight to the flotation process.
  • Vitrinite and inertinite each behave very differently in flotation. Generally, vitrinite recovery increases with increasing particle size, and vice-versa for inertinite. The flotation rate of inertinite is generally significantly lower than that for vitrinite.
  • As the flotation process relies on air-particle contact and adhesion (hydrophobicity), and the hydrophobicity depends on the nature of the coal and mineral matter in each particle, CGA is able to provide a fundamental approach to understanding coal flotation.
  • Various different forms of modelling are possible using CGA, including providing a direct quantitative link to pseudo-density models.
  • The use of CGA in flotation modelling overcomes the severe limitation of all alternative model approaches, in that the CGA models are based on the actual particle compositions, and not on any inferences such as flotation feed ash value.
  • The most promising form of CGA model is that which was investigated in associated Project C27033, where an adaptation of CGA was employed to measure the surface composition of particles, rather than the volumetric composition, and relate the surface composition to flotation performance. The particular benefits of that approach are that all CGA data are employed without resorting to any form of particle class-grouping; and the only information that needs to be pre-procured are the flotation rate constants for each of the pure components: vitrinite, inertinite, liptinite and minerals. This project generated the pure component rate constants which could then be used by Project C27033.
  • For any given flotation feed that has been characterised by CGA, the modelling methodology identified in this project and C27033 provides a quantitative basis upon which to estimate flotation yield for different flotation devices and different flotation circuit configurations. Project C27033 has specifically identified the notion of a threshold rate constant, which provides a quantitative basis to estimate the different operating performance of different flotation devices.
  • Data presented in the Report provides a quantitative basis for understanding the impact of changes in reagent dose rate upon flotation rate for each of the feed components.
  • The percentage of minus one micrometre material in flotation feed is often very significant. CGA does not measure particles smaller than one micrometre, and so this is a limitation of CGA which needs to be accounted for.
  • The flotation feed washability measured by CGA appears to define the best possible ('ultimate') flotation performance that may be attained, although the CGA washability needs to be corrected for the minus one micrometre material.
  • This project has demonstrated the application of CGA as a tool to provide a more fundamental basis for modelling flotation performance. The CGA data provide a very clear picture of where valuable product coal components are being lost to tailing, thus providing a tool for flotation cell and flotation reagent suppliers to target improved performance.


Health and safety, productivity and environment initiatives.

Recently Completed Projects

C26070Industrialisation Of Proof Of Concept Wall-Flow DOC + Filter System

The need to protect workers from diesel particulate matter (DPM) had...

C26006Coal Burst Monitoring Technology Using Microseismicity – Microseismic Data Capturing And Documentation

Coal burst is a violent collapse of the coal wall or roof in develop...

C20038Standardised Subsidence Information Management System

As an empirically-based discipline of engineering/science, subsidenc...


Open Cut

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

Recently Completed Projects

C27046Estimation Of True Deformation Vector From Slope Radar Monitoring

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

C29003Wear Debris Removal From Dragline Commutators

The original aim of this project was to establish a method of removi...

C28037Local Scale Dispersion Modelling To Support ACARP Emission Factors

There remains significant concern in the industry regarding the accu...

Open Cut

Coal Preparation

Maximising throughput and yield while minimising costs and emissions.

Recently Completed Projects

C6046Optimising Coal Fragmentation For Improved Recovery

Uncontrolled fragmentation, in particular that resulting in the gene...

C25019Adaptation Of Coal Grain Analysis To Improve Flotation Yield Estimation

This project involved sampling of full-scale flotation circuits at ...

C27033Comprehensive Flotation Model Using CGA Particle Surface Composition

The aim of this project was to adapt existing particle based flotat...

Coal Preparation

Technical Market Support

Market acceptance and emphasising the advantages of Australian coals.

Recently Completed Projects

C24057Using CGA To Investigate The Links Between Inertinite Fusibility And Coke Structure

Previous projects C16047 and C20008 identified some coals from diffe...

C27036Improved Understanding Of Coke Quality Using 3D Immersive Visualisation And Statistical Characterisation Of Microstructure Properties

This project carried out an explorative study into the use of a 3D v...

C27047Combustion Characteristics Of Australian Export Thermal Coal Using Advanced Imaging Techniques

During pulverised fuel combustion, coal particles are rapidly pyroly...

Technical Market Support

Mine Site Greenhouse Gas Mitigation

Mitigating greenhouse gas emissions from the production of coal.

Recently Completed Projects

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...

C27008Selective Absorption Of Methane By Ionic Liquids

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

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