ACARP ACARP ACARP ACARP
Technical Market Support

Structural Differences Between Coking Coals of the Sydney Basin and Other Sources

Technical Market Support » Metallurgical Coal

Published: April 17Project Number: C24060

Get ReportAuthor: Richard Sakurovs, Mihaela Grigore, Lukas Koval and Alireza Keshavarz | CSIRO

Cokes made from Australian coals of relatively low fluidity can have better strength and reactivity values than their equivalents prepared from European or American coals. Although this systematic difference is well known, it has long been an issue in contract negotiations in sales of Australian coking coals. There have been many attempts to identify the cause of this difference. Early work found that some inertinites in Australian coals are fusible to some extent, but this didn't resolve the problem since some inertinites in Carboniferous American and European coals were found to be fusible as well. There was some evidence that in some cases a greater fraction of the Australian inertinites was fusible than those sourced from other countries but the results were not unequivocal, and there was no mechanistic connection between this result and coke properties. The connection between inertinite fusibility, low fluidity of Australian coking coals and coke properties remains unexplained. These coals are the Permian coals from the Sydney and Bowen basins from Eastern Australia, which dominate Australian coking coal exports. In this report 'Sydney basin coals' is used as short hand to describe these coals.

Recently a fundamental, physical difference was found between the inertinites in Sydney Basin coals and Carboniferous coals from America and Europe. Using Small Angle Neutron Scattering (SANS) it was found that gases can flow into (and out of) nanopores, 10-20 nm in size, in inertinites in the Sydney basin coals; however these gases do not readily penetrate the same-sized nanopores in inertinites in American and European coals. These pores are much too small to be detectable by optical microscopy, which is one reason why this difference hasn't been observed before. The initial study was extended to include some West Canadian coals, which also have low fluidity and good coking propensity, and it was found that their inertinites were almost as permeable to gases as the inertinites in Sydney Basin coals. Thus the nanostructure of coals affects gas transport in the coal. Gas transport in the coal and coke during the coking process plays an important role in determining swelling, coke oven wall pressure and the properties of the final coke.

If the reason for the differences in coking behaviour of Sydney Basin and Carboniferous coals from Europe and America is due to the nanostructure of the inertinites affecting the flow of gas inside coal particles, then there are a number of questions arising from this interpretation. For instance:

1. What is the nanostructure of inertinites in coals from other regions? Is it like Sydney Basin coals, European coals or different again?

2. Can these regional differences in inertinites be picked up by other techniques? Gas sorption rates, for example.

3. Do these differences in structure carry over to the cokes?

This project was designed to answer these three questions.

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