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European Lithium Ltd. 28.03.2019

Metallurgical Testwork Hits Its 1st Milestone Ahead of Schedule During Definite Feasibility Study’s Work Program

 

HIGHLIGHTS

 

-          European Lithium Ltd receive Interim Metallurgical Testwork Report by Dorfner/Anzaplan

-          Report covers Sensor Based Sorting well ahead of schedule

 

March 28, 2019 – European Lithium Limited (ASX:EUR, FRA:PF8, VSE:ELI, NEX:EUR) (European Lithium or the Company) is pleased to announce a key milestone of the definitive feasibility study (DFS) at the Company’s advanced Wolfsberg Lithium Project (Wolfsberg Project), in Austria, has been achieved. Dorfner/Anzaplan (Dorfner), appointed for the complex metallurgical testwork has presented their Interim report covering the Sensor Based Ore Sorting for the Wolfsberg Project.

 

The Company has received approval from Dorfner to provide the information directly from the Report: “FS Testwork for the Wolfsberg Lithium Project – Part 1.1. Sensor based sorting.

 

Executive Summary

 

European Lithium is in the process of developing its “Wolfsberg” lithium mineral project and aims at becoming a lithium chemicals producer as well as a supplier of spodumene, quartz and feldspar products for the glass and ceramics industry. The 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 test work was conducted to reduce the host rock dilution and pre-concentrate the spodumene ore by rejecting host rock. It was applied to the fractions +8 -25 mm and +25 -70mm. Tests were carried out separately for the AHP and MHP type materials in both size fractions. The following sorting tests were carried out:

 

-          Laser sorting tests on bulk samples (approx. 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

 

Bulk Laser Sorting

 

The objective of the bulk laser sorting test work was to confirm the results of the previous test work and produce sorted product for the subsequent lab and pilot test work. In all tests a scavenger sorting was conducted, to recover any spodumene misplaced to the sorter rejects from the rougher stage.

 

 

 

Figure 1: Laser sorter: 3D model of Laser sorter (top) and Laser sorter test rig in Tomra’s technical center used for fraction +25 mm

 

Based on the results of initial screening and laser sorting tests an overall mass balance for both, the MHP ore and the AHP ore sample, was estimated. In case of AHP ore (rougher sorting only) a mass reduction of 25.1 wt.-% of initial mass was realised by rejecting host rock during sensor based sorting. A lithium recovery of 93.1 wt.-% in sorted AHP ore was calculated. The sorted ore is the combined product after sorting of fraction +25 mm and fraction +8 -25 mm as well as fines -8 mm from the initial screening step. In addition, spodumene is pre-concentrated and lithium content increased from 1.0 wt.-% to 1.3 wt.-% Li2O after sorting. In the case of MHP ore (rougher sorting only) a mass reduction of 23.2 wt.-% of initial mass was realised by rejecting host rock during sensor based sorting. The lithium recovery was calculated to 92.5 wt.-% in the sorted MHP ore. Lithium content increased from 0.9 wt.-% in the initial head sample to 1.1 wt.-% Li2O after sorting. The results are comparable to the 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 as well to 95.5 wt.-% for MHP ore.

 

XRT Sorting

 

The use of XRT sorting as an alternative to laser sorting was investigated. Although laser-based sorting provided excellent recovery and waste rock rejection in the testwork, it requires the ore to be pre-rinsed.

 

 

Figure 2: XRT sorter: 3D model of XRT sorter (top) and XRT sorter test rig in Tomra’s technical center

 

Compared to the laser sorting the XRT sorting was significantly less selective. This is indicated by the reduced recovery in the rougher stage. The 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 (8.4 to 20.6 wt.-%) and mass (6.3 to 23.5 wt.-%, for comparison 2.8 to 5.7 wt.-% in laser sorting) was separated in the scavenger product for recirculation to feed. Therefore, the laser sorting technology appears to be the preferred solution for sorting of the ore form the Wolfsberg Project.

 

Laser Sorting High Dilution

 

High dilution with host rock is expected with up to 80% (host rock content in sorter feed) when mining narrow veins during the life of mine. Therefore, laser sorting test were conducted with a recombined sample with approx. 80% host rock dilution. A flow sheet with rougher, scavenger and cleaner sorting was tested.

 

The quality of the final product after sorting (cleaner product) is similar in quality as the products yielded after sorting of the samples as received (scavenger product). The lithium recovery in the cleaner product was in the range of 53.2 to 67.6 wt.-%. Significant amounts of lithium is 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.

 

Lithium was analyzed in the host rock, which is not connected to spodumene but rather to lithium bearing minerals in the host rock (holmquistite), influencing the lithium recovery calculation for the 80/20 case. 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.

 

Dietrich Wanke, CEO commented on the Interim Report for the DFS “It is a significant milestone to achieve during the company’s complex metallurgical testwork. 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.”

 

Tony Sage, Chairman, commented on the Interim ReportWe are pleased to hit this testwork milestone well ahead of schedule and our team are focused on maintaining this progress to complete the DFS.

 

Tony Sage

Non-Executive Chairman

European Lithium Limited

 

- END

 

Visit the Company’s website to find out more about the advanced Wolfsberg Lithium Project located in Austria.

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