Metallurgical Testing Provides Further Positive Results
Mina do Barroso Lithium Project, Portugal
Savannah Resources plc (AIM: SAV and SWB: SAV) (‘Savannah’ or the ‘Company’), the AIM quoted resource development company, is pleased to announce that Phase 2 metallurgical test work has returned encouraging results at the Mina do Barroso Lithium Project (‘Mina do Barroso’ or the ‘Project’), located in Portugal (Figure 1). Further follow up work is now underway. To view the press release with the illustrative maps and diagrams please use the following link:
· Analysis confirms high-grade spodumene mineralisation with a lithium content of around 1.7% Li2O and low impurities – less than 0.5% Fe2O3
· Mineralogy analysis confirms spodumene is the dominant lithium mineral with low contaminants
· Test work continues to confirm well proven, conventional metallurgical processes will produce a spodumene concentrate
· Preliminary test work suggests that by using a process route combining both gravity separation and flotation that a total recovery of at least 80% at a concentrate grade of over 6% Li2O is likely to be achieved
· Heavy Liquid Separation (HLS) testing and small-scale pilot testing confirms industry benchmark, low-iron, 6% Li2O concentrate can be produced by low cost gravity processing
· Test work completed to date suggest at least 40% of the contained lithium can be recovered via gravity processing
· Preliminary tests show that over 70% of lithium not recovered by gravity can be recovered by flotation at a grade of over 6% Li2O
· Further improvements are expected as part of Phase 3 of the test work programme currently underway – diamond drilling is underway at Grandao and Reservatorio to collect additional samples for the Phase 3 test programme, with results expected in Q3 2018
· Mr Noel O’Brien, a metallurgist and lithium processing expert with over 35 years’ experience has been appointed as a technical consultant to direct Savannah’s metallurgical test work programme
Savannah’s CEO, David Archer said: “We are delighted to see the results to date show that Mina do Barroso continues to demonstrate impressive metallurgical results, with spodumene being the dominant lithium mineral that can be recovered using conventional processing techniques to produce an industry benchmark product with low contaminants at good recoveries.
“Mina do Barroso continues to shape up as a European near-analogue to the highly successful Western Australian spodumene producers. It is also important to remember that globally, ALL significant hard-rock lithium mines currently supplying the makers of lithium carbonate extract spodumene.
“We hope that more metallurgical work will continue to refine and improve these already excellent results and we are delighted to welcome Noel O’Brien as a technical consultant to direct this programme.”
Figure 1. Mina do Barroso Project Summary Map showing prospects and drilling completed to date
Summary of Phase 2 Metallurgical Test Work Programme and Results
The first series of testing involved conducting sighter tests on a combined sample of mineralisation from Grandao, NOA and Reservatorio to establish metallurgical response and to determine the dominant lithium minerals.
The samples were crushed to 10mm, 6.3mm and 4mm and screened at 0.5mm. The crushed samples were subjected to densimetric profiling tests using Heavy Liquid Separation (HLS) at four densities of 2.9,2.8,2.7 and 2.6.
Each HLS SG fraction was examined by X-Ray Diffraction (“XRD”) to establish the dominant lithium minerals.
These results are extremely encouraging and established the key attributes of:
· The dominant lithium mineral is spodumene. There is very little petalite and this is confirmed by the low Li2O assays in the 2.7 and 2.6 float fractions. Petalite is a light mineral that has a lower lithium content and if present, will show up in these light fractions.
· The HLS results show improving lithium recovery and grades as the crush size decreases. At a 4mm crush size, 37% of the lithium in the +0.5mm fraction has been recovered at a grade of 6.19%.
· There are low impurities and an iron content in the spodumene of less than 0.5% Fe2O3 which is well below the threshold of 1.4% Fe2O3 demanded by most off-takers.
· An overall head grade of 1.7% Li2O was obtained for the composite sample which was higher than expected based on the past rock chip results
A second series of tests were conducted on a larger composite of the ore. This had a head grade of 1.73% Li2O. Sub-samples were crushed to 4mm and 3.35mm and screened at 0.5mm.
Samples were processed in a small-scale gravity DMS pilot plant that has a 100mm cyclone.
For further information please visit www.savannahresources.com
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