Open Cut » Geology
This project has analysed the concentrations of 50 elements not typically measured in coal in nearly 90 Australian coal samples from Queensland and New South Wales. The project provides the first dataset and map of its kind for Australian coal.
Internationally, alternative coal use is actively sought to protect jobs and revenue as traditional coal use declines. In particular, the use of coal to source critical minerals including rare earth elements (REE) is an area of heavy investment at present in USA. Coal content knowledge of Australian coals is sparse so predictive mapping to match coal with alternative uses has not been possible until now.
The work performed in this project intends to provide data that can be used to clarify potential targets that may improve the industry's long term potential. Eighteen contributors (coal mines and power plants) donated more than 150 samples for analysis. The project plan allowed 89 samples to be analysed, carefully selected to represent 6 basins, covering a range of coal measures and seams of varying ages. Results indicate a high incidence of above crustal average concentrations of many of the 50 elements analysed. Rare earth elements (REE) in particular, are elevated by up to 6 times more than average crustal concentrations in some samples.
The results were combined with pre-existing data of the elemental signatures of other rocks and coals in eastern Australia, mapped spatially, and compared graphically to determine potential sources of elements.
The achieved objectives and aims of this project were to:
- Deliver the first coal content map of its kind for Australian coal;
- Present elemental composition as a database of the samples assessed and a report interpreting the results including geological provenance of the elemental matter.
Key findings are:
- Element concentrations (i.e. rare earth elements and yttrium - REY) appear to be directly correlated with the amount of mineral matter present in coal (ash);
- Lithium, rare earth elements, gold and bismuth tend to be concentrated above average crustal abundance and have to be assessed further in coal products in Queensland.
While concentrations of elements in the samples found to be above crustal averages may not be equal to those of typical ore grades, such concentrations may warrant further investigation. Further, mineral association of each element must be determined prior to evaluating economic opportunities and whether suitable extraction techniques can be identified.
This report consists of:
- A detailed literature review of the locations from a geological perspective and the methods used, including selected treatment of data for interpretation.
- The results are laid out in chart and map forms, providing the full dataset in Appendix A (Excel format) and more detailed maps in Appendix B.
- Appendix C consists of summary reports that were provided to each of the sample contributors.