Coal Preparation

Enhanced Desliming using a Reflux Flotation Cell

Coal Preparation » Fine Coal

Published: November 15Project Number: C20043

Get ReportAuthor: James Dickinson and Kevin Galvin | The University of Newcastle

The objective of this project was to investigate the potential to improve the desliming performance of fine coal flotation by using a Reflux Flotation Cell (RFC), and to establish increased certainty in the scalability from a laboratory scale unit to a pilot scale unit for future construction of a full scale RFC unit. The RFC applies a fluidization approach to the delivery of wash water and utilises a system of inclined channels below a fluidized bed of bubbles to provide a powerful mechanism for segregating gas bubbles from the downward liquid flow that exits the vessel. The enhanced segregation capacity provided by the inclined channels permits vastly higher rates of wash water and bubble interfacial surface than presently possibly in industry, and superior counter-current washing of the rising bubbles to obtain high quality desliming.


The RFC at both laboratory and pilot scale repeatedly demonstrated a robust separation performance obtaining combustible recovery in accordance with the tree flotation curve for a variety of flotation feeds sourced from hydrocyclone overflow, and other well characterised, difficult to deslime coal streams. Notably, the knee of the tree curve was shown to be readily targeted through independent control of the overflow liquid flux and wash water flux, made possible due to the unique hydrodynamics within the RFC.


The findings of this project address a key problem facing many New South Wales and Queensland coal operations concerning the recovery of fine coal, by demonstrating an effective method for readily rejecting fine slimes from flotation product. Further, the RFC could be extended to the production of ultra-low ash coal. The unique hydrodynamic environment in the RFC allows for the treatment of very fine, high mineral matter coal feeds, such as hydrocyclone overflow, which would otherwise be discharged to tailings dams. The knowledge gained from the pilot trial has provided a confident platform for future construction of a full scale RFC.


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