ACARP ACARP ACARP ACARP
Coal Preparation

Improving the Control of Product Coal Moisture Based on Unsaturated Soil Mechanics Principles

Coal Preparation » Dewatering

Published: September 08Project Number: C15061

Get ReportAuthor: David Williams, Stuart Whitton | University of Queensland, Mechanical Advantage

ACARP Project C15061 addressed a Research Priority of improved recovery by reducing product coal moisture.  This was achieved through applying unsaturated soil mechanics principles to better understand the water storage capacity, dewatering and re-wetting of product coal, during processing and on the mine and port stockpiles.  The preliminary application of the approach to samples provided by Anglo Coal demonstrated the potential for it to provide a direct means of assessing the effectiveness of different dewatering methods for different product coal size fractions from different mines, assessing the potential for drying of stockpiled product coal due to gravity drainage, wind and solar action, and assessing re-wetting due to rainfall or watering for dust suppression.  These have implications for the future processing of product coal and for the management of product coal stockpiles to avoid high moisture contents.  The approach has potential to be applied to existing mines based on the testing of the various product coal size fractions, and to new projects based on the testing of borehole samples.

The mining, handling, processing, stockpiling, reclaiming (particularly if this involves dozing) and transportation of product coal results in the production of fines, which have an affinity for moisture.  Improvements in fine coal recovery, and the mining of coal that is prone to breakdown, exacerbate this.  The total moisture content at which product coal is exported has implications for its handleability, shipment and final use.  Excessive moisture makes the coal difficult to unload from ships, there is no financial return from shipping excess water, and excess moisture in the coal requires expending energy to remove it.  Product coal is therefore required to be delivered to the port for export below a specified total moisture content, typically 10 to 11% (based on mass of water/total mass, expressed as a %).  For each 1% by which the product coal exceeds this specified value, a financial penalty is imposed equivalent to the energy value of the extra moisture, up to a rejection moisture, of typically about 15%, at which rejection of the shipment may occur or severe financial penalties are imposed.

Laboratory Soil Water Characteristic Curve (SWCC) testing was carried out on a number of product coal size fractions and composite product coal samples supplied by mines in the Bowen Basin and Hunter Valley.  These samples represented the main coal seams mined, focusing on those that experience or expect to experience problematic product coal total moisture contents.  Field data on total moisture content were also collected from a product coal stockpile at one of the participating mines following 8 days of atmospheric drying, and this product coal was subjected to laboratory wetting up simulations.  The successful conclusion of the project provides a potential means of selecting the most appropriate dewatering technique for a particular product coal size fraction, and best means of managing product coal stockpiles to minimise the likelihood of excessive moisture.  The methodology and experience gained during the course of the project may readily be extended to a greater range of coal measures and specific product coals, and to the design, construction and management of a greater range of product coal stockpiles, both at mines sites and ports.

Underground

Health and safety, productivity and environment initiatives.

Underground

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

NERDDC

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

NERDDC