Open Cut » Geology
This project explores the fate and concentration potential of critical elements present in coal measures, as they are moved through a processing plant, from start-to-end.
The project was very kindly supported by two mines:
- Mine A provided 16 core samples and ten washplant samples;
- Mine B provided ten core samples and four washplant samples.
The 40 samples were analysed in a combination of CSIRO, ALS and Bureau Veritas laboratories using a range of processes to ensure optimal data collection. Up to 60 elements were explored where possible, depending on material provided. Rare earth elements (REE) were of particular interest as some 'spikes' occurred above background expectations. Further analysis was conducted in our laboratory where we investigated gamma as an indicator for potential high REE levels.
Key project findings are:
- Elements in coal measures are most likely to be concentrated in coal partings more than coal;
- In the wash plant elements are most likely more concentrated in coarse rejects than other waste streams of particular interest is the FC4 parting;
- Light REE highest concentrations were found in sample MA8_FC4_CM_104, a banded carbonaceous mudstone parting in the FC4 ply;
- Heavy REE concentrations present similar patterns, the highest being in sample MA1_YT_TF_95.
A high gamma signal of tuffaceous sediments in the Bowen Basin has been confirmed by researchers for decades. Researchers found both average gamma and average REE concentrations in the Mine B samples; in comparison, Mine A samples showed strong gamma spikes (above background) and higher REE concentrations than the samples. This provides some evidence to support hypothesis that gamma and REE levels may be connected.