REG - Savannah Resources - Successful Completion of Locked Cycle Testing

Savannah ResourcesAnnouncement

21/06/2022 07:00

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RNS Number : 5556P  Savannah Resources PLC  21 June 2022

 

 

21 June 2022

 

Savannah Resources Plc

(AIM: SAV, FWB: SAV and SWB: SAV)

('Savannah' or the 'Company')

 

Successful Completion of Locked Cycle Testing

Excellent Recoveries above Target Lithium Grades

 

Savannah Resources plc, the European lithium development company, is pleased
to announce that it has successfully achieved another major project milestone
for its 100% owned Barroso Lithium Project (the 'Project'), with locked cycle
testing ('LCT') completed, utilising the recently finalised process flowsheet
and optimised grind size of 150 micron, delivering further excellent
recoveries. Locked cycle testing is an important process in ensuring an
accurate process flow sheet and verified inputs to the upcoming Definitive
Feasibility Study ("DFS").

 

Highlights:

·    Three LCTs were completed to simulate the continuous operation of a
process plant and to refine the reagent consumption of the process flowsheet

·    The LCT yielded a concentrate grade of 5.5% Li(2)O ('SC5.5') and
global recoveries in the range of 77%-81% at laboratory scale

·    This supports the results previously reported in the ore variability
programme, which achieved Li(2)O recoveries in the range of 70%-79.5% at
laboratory scale with low levels of impurities, and suggests that improved
levels of recoveries are achievable

·    Optimisation of the reagent dose rates between test 1 and test 3
showed a 39% reduction in reagent use which should have significant operating
cost ('OPEX') benefits for the Project which will be captured in future
economic evaluations

·    These positive results will be utilised in resource and mine
optimisation, and as the basis for the upcoming DFS to support the proposed
development

·    Based on the encouraging results achieved to date, planning for the
pilot plant test work programme is underway

 

To view the full press release including any maps, figures or tables, please
use the following link:

http://www.rns-pdf.londonstockexchange.com/rns/5556P_1-2022-6-20.pdf
(http://www.rns-pdf.londonstockexchange.com/rns/5556P_1-2022-6-20.pdf)

 

David Archer, Savannah's Chief Executive Officer said: "Having finalised our
innovative, environmentally enhanced process flowsheet for the Project in
February, we are very pleased with the results produced during this subsequent
LCT phase. We believe that this testing phase better replicates the conditions
associated with the continuous circuit found in a spodumene flotation plant,
so to produce a concentrate of 5.5% Li(2)O based on laboratory recoveries at
or around 80% is very encouraging. This is particularly so when testing also
shows there may be an opportunity to additionally reduce associated reagent
volumes and operating costs.

 

"The large amount of data already collected, along with results from the
remaining, larger scale, metallurgical testing will be used in the Definitive
Feasibility Study to help us in our efforts to optimise all aspects of the
Project, including minimising its use of raw materials and energy.

 

''We look forward to bringing further news on the large scale bulk float tests
and pilot plant test work programmes during the second half of 2022."

 

Background

A locked cycle test is a repetitive batch test which recycles the tails
material between flotation stages to better simulate a continuous circuit at
lab scale. The test is used to verify that the inclusion of recycled solids to
the previous stage does not negatively impact the flotation performance and
allows an investigation into how reagents may build up within the circuit and
the optimisation of reagent dose rates. The LCT programme was supervised by
MinSol Engineering Pty Ltd ('MinSol') between Q1 and Q2 2022 and implemented
the recommendations from the variability programme that was completed in
conjunction when possible.

The LCT programme was undertaken with the following objectives:

·    Verify the impact of recycled material on the efficiency of the
flotation stage

·    Provide confidence in the repeatability of the flotation performance

·    Further optimisation/reduction of reagent dose rates

·    Produce representative process water and by-products samples for
future test programs

 

The LCT programme was undertaken on a single composite grading 1.23% Li(2)O
that was representative of Grandao stage 1, which is the dominant deposit in
the first 10 years of the project life. The programme allowed for three
separate tests to be undertaken with 10 cycles completed in each test to allow
reagent rates to be reviewed and manipulated during the test and then return
to steady state.

 

Summary of Key Results

 

Sighter Flotation test:

Prior to undertaking the first lock cycle test, a sighter flotation test
('SF') was completed to assess the reagent dose rate required and the typical
performance of the sample. The results yielded a high quality spodumene
concentrate at the Project target grade of 5.50% Li(2)O at an 85% flotation
stage recovery with no optimisation of the reagent dose rate. The sample
performed excellently due to the low losses associated with the Dense Media
Separation pre-concentration stage, de-sliming and magnetic separation. The
overall global performance of the sighter test is detailed in the figures
following.

 

Table 1 - Sighter Flotation Global Performance

 Composite Head Grade (% Li(2)O)  Global Deportment of Li(2)O (%)
                                  Floats  Slimes  Mags    Mica Cons  Flotation Tails  SC5.5
 1.23                             2.5     2.1     2.0     11.0       1.1              81.4

 

 

Figure 1 - Sighter Flotation Global Performance

The graph for Figure 1 can be viewed through the PDF link above.

 

Lock Cycle Test 1:

LCT 1 was undertaken with fixed reagent dose rates for the 10 cycles after
regular review of the key product masses. The average results for the final 2
cycles (9 and 10) achieved a concentrate grading 5.50% Li(2)O at a stage
recovery of 87.5%. This resulted in a global recovery of 81.5%.

 

Lock Cycle Test 2:

After the promising results of LCT 1 showed a final 2 cycle performance equal
to the sighter flotation test, LCT 2 investigated dropping the reagent dose
rate at cycle 4 by 15% and again at cycle 7 by a further 15%. The results
suggested that the process had not reached steady state after the 10 cycles,
however, the results were encouraging by indicating that the recycled solids
loading could allow for a reduction in reagent dose rate, with only a minor
increase in the losses to the rougher tails.

 

Lock Cycle Test 3:

LCT 3 incorporated more comprehensive water recycling by collecting all
filtrates from the tails and concentrate fractions for reuse. The recovered
masses at each stage were regularly reviewed and a reagent overdose/build-up
stage was encountered, and the rates reduced to suit. The final reagent dose
rates were a 39% reduction from the original dose rates, but the test was
still able to achieve a high-grade product at suitable recoveries.

 

The final two products from each LCT and the SF are presented in the figure,
which can be viewed through the PDF link above.

 

Figure 2 - Flotation Global Performance Comparison

 

The possible overall reduction in reagents should have significant OPEX
benefits for the Project and will be captured in future economic evaluations.

 

It is noted that the recoveries stated above are based on lab scale, and
industry standard scale up factors should be applied to account for increased
slimes generation and therefore lithia losses and equipment inefficiencies.

 

The programme was successfully able to produce representative samples of
by-products for analysis and OEM test work.

 

Photograph 1. Locked Cycle Testing in Progress

 

Future Work Plan

Further work is planned in Q3 and Q4 of 2022 to refine the process operating
conditions and investigate further opportunities to improve process recovery.
The next stage of the test work programme will include:

·    Large scale bulk float tests

·    Water circuits and treatment

·    Pilot Plant testing

 

The Company will provide further updates as appropriate.

 

Competent Person Statement

The information in this announcement that relates to exploration results is
based upon information compiled by Mr Dale Ferguson, Technical Director of
Savannah Resources PLC. Mr Ferguson is a Member of the Australasian Institute
of Mining and Metallurgy ('MAusIMM') and has sufficient experience which is
relevant to the style of mineralisation and type of deposit under
consideration and to the activity which he is undertaking to qualify as a
Competent Person as defined in the December 2012 edition of the "Australasian
Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves"
(JORC Code).  Mr Ferguson consents to the inclusion in the report of the
matters based upon the information in the form and context in which it
appears.

 

The information in this release that relates to metallurgy and metallurgical
test work has been reviewed by Mr Robert Simmons, MAusIMM, B. Eng. (Chemical
Engineering). Mr Simmons is not an employee of the Company but is engaged as a
contract consultant. Mr Simmons is a Member of the Australasian Institute of
Mining and Metallurgy, he has sufficient experience with the style of
processing response and type of deposit under consideration, and to the
activities undertaken, to qualify as a competent person as defined in the 2012
edition of the "Australian Code for the Reporting of Exploration Results,
Mineral Resources and Ore Reserves". Mr Simmons consents to the inclusion in
this report of the contained technical information in the form and context as
it appears.

 

Regulatory Information

This Announcement contains inside information for the purposes of the UK
version of the market abuse regulation (EU No. 596/2014) as it forms part of
United Kingdom domestic law by virtue of the European Union (Withdrawal) Act
2018 ("UK MAR").

 

Savannah - Enabling Europe's energy transition.

 

 

**ENDS**

Follow @SavannahRes on Twitter

Follow Savannah Resources on LinkedIn

 

For further information please visit www.savannahresources.com or contact:

 

 Savannah Resources PLC                               Tel: +44 20 7117 2489

 David Archer, CEO

                                                      Tel: +44 20 3470 0470

 SP Angel Corporate Finance LLP (Nominated Advisor)

 David Hignell / Charlie Bouverat

                                                      Tel: +44 20 7220 0500

 finnCap Ltd (Joint Broker)

 Christopher Raggett/ Tim Redfern

 RBC Capital Markets (Joint Broker)                   Tel: +44 20 7653 4000

 Farid Dadashev/ Jamil Miah
                                                      Tel: +44 20 7220 1666

 WH Ireland Limited (Joint Broker)

 Jessica Cave/ Ben Good (Corporate Finance)

 Aimee McCusker (Corporate Broking)

                                                      Tel: +44 20 3757 4980

 Camarco (Financial PR)

 Gordon Poole/ Emily Hall

 

About Savannah

 

Savannah is the owner of the Barroso Lithium Project, located close to key
infrastructure in Northern Portugal which contains the most significant
spodumene lithium resource in Western Europe. With a positive Scoping Study
which outlined a conventional mine and concentrator operation producing
175,000t of spodumene concentrate per annum, Savannah is progressing the
development and environmental licencing of the Barroso Lithium Project. A
Definitive Feasibility Study is underway, and Portugal's environmental
regulator is currently evaluating Savannah's Environmental Impact Assessment
study. The Company is listed and regulated on the London Stock Exchange's
Alternative Investment Market (AIM: SAV). The Company's ordinary shares are
also available on the Quotation Board of the Frankfurt Stock Exchange (FWB:
SAV), and the Börse Stuttgart (SWB: SAV).

 

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