European Lithium Ltd (ASX:EUR) (FRA:PF8) (VSE:ELI) (AQSE:EUR) has reached a key test work milestone, demonstrating that ore from the Wolfsberg Lithium Project in Austria can be sorted in different ways to achieve consistent high-quality products.
The complex metallurgical test work is being carried out by German company Dorfner/Anzaplan, which has delivered the interim ‘Sensor Based Ore Sorting for the Wolfsberg Project’ report well ahead of schedule.
These tests form part of definitive feasibility study (DFS) work for the company’s integrated European lithium supply strategy centred on the Wolfsberg project.
European Lithium CEO Dietrich Wanke said: “It is a significant milestone to achieve during the company’s complex metallurgical test work.
“These results prove the ore can be treated from AHP and MHP sources and can be sorted in different ways to achieve repeatable and consistent high-quality products.”
European Lithium aims to become a lithium chemicals producer as well as a supplier of spodumene, quartz and feldspar products for the glass and ceramics industry.
READ: European Lithium sees massive opportunity to secure Wolfsberg Lithium Project financing through €1 billion funding program
The Wolfsberg resource essentially comprises lithium pegmatite veins hosted in amphibolite (AHP) and mica schist (MHP).
The AHP ore contains relatively coarse-grained spodumene crystals whereas the MHP bears much finer crystals.
For the test work, samples were taken by European Lithium from the -70 mm bulk sample stockpiles and shipped to Dorfner.
Sensor-based sorting was conducted to reduce host rock dilution and preconcentrate the spodumene ore by rejecting host rock.
Three tests utilised
Tests were carried out separately for the AHP and MHP type materials in the +8 -25mm and +25 -70mm size fractions.
The three tests were:
- Laser sorting tests on bulk samples (approximately 50 tons feed) including scavenger sorting.
- XRT sorting tests as an alternative to laser sorting including scavenger sorting.
- Laser sorting on recombined 80% (host rock)/20 (ore) mix.
3D model of Laser sorter.
In the bulk laser sorting tests results are comparable to previous sorting results, where 92.0 wt-% overall lithium recovery for MHP and 93.0 wt-% for AHP were achieved.
When adding the scavenger sorting stage in the calculation, the overall lithium recovery in the sorted ore improves to 95.5 wt-% for AHP ore and to 95.5 wt-% for MHP ore.
Compared to laser sorting, the XRT sorting was significantly less selective as indicated by the reduced recovery in the rougher stage.
XRT sorter test rig in Tomra’s technical centre.
Lithium recovery using XRT in the rougher product was in the range of 76.2 to 85.2 wt-%, compared to 86.3 to 92.6 wt-% using laser sorting at a similar product quality.
In addition, a significant amount of lithium and mass was separated in the scavenger product for recirculation to feed.
3D model of XRT sorter.
Therefore, the laser sorting technology appears to be the preferred solution for sorting of Wolfsberg ore.
The third testing method was utilised as high dilution with host rock is expected with up to 80% when mining narrow veins during the life of mine.
A flow sheet with rougher, scavenger and cleaner sorting was tested.
The quality of the final product after sorting (cleaner product) is similar as the products yielded after sorting of the samples as received (scavenger product).
Lithium recovery in the cleaner product was in the range of 53.2 to 67.6 wt-%.
Significant amounts of lithium are also in the cleaner tailings and scavenger product (6.3 to 19.6 wt-%).
These two products are recirculated in the commercial process, therefore, most of the lithium in these products should be recoverable.
The source of lithium in the host rock is recommended to be investigated further and has to be taken into account when using the sorting results for further recovery estimations during engineering studies.
“Focused on maintaining progress”
Chairman Tony Sage said: “We are pleased to hit this test work milestone well ahead of schedule and our team is focused on maintaining this progress to complete the DFS.”