TIDMSAV
RNS Number : 3434T
Savannah Resources PLC
14 November 2019
14 November 2019
Savannah Resources Plc
Mina do Barroso Lithium Project
Robust Results from Grandao Variability Test work and
Encouraging Preliminary Metallurgical Test Work Results from both
Pinheiro and Aldeia Deposits
Savannah Resources plc (AIM: SAV, FWB: SAV and SWB: SAV)
('Savannah' or the 'Company'), the AIM quoted resource development
company, which is focused on becoming Europe's most significant
producer of spodumene lithium from its Mina do Barroso Project in
Portugal ('Mina do Barroso', 'MdB' or 'the Project'), is pleased to
announce that its ongoing metallurgical test work programme
continues to successfully produce saleable grades of spodumene
lithium concentrate with excellent recoveries.
To view the announcement with the illustrative maps and
diagrams, please use the following link:
http://www.rns-pdf.londonstockexchange.com/rns/3434T_1-2019-11-13.pdf
Highlights
-- Excellent progress made with metallurgical test work,
underlining the Mina do Barroso Project's potential to become a key
supplier of spodumene lithium to the European electric vehicle
supply chain
-- Savannah has successfully produced high quality spodumene
concentrates from the Grandao, Pinheiro and Aldeia deposits at the
Project, using a "whole of ore flotation" process developed during
the previous test work programmes
-- The recovery rates and the purity of spodumene concentrates
produced from varying samples taken from the Grandao orebody
vindicates Savannah's decision to expand its test work programme to
produce a robust processing flowsheet
-- Savannah continues to de-risk the Project by building up a
comprehensive understanding of how best to manage the metallurgical
outcomes for the Mina do Barroso deposits
Grandao deposit:
-- To confirm that a robust process flow sheet can be developed
to achieve saleable lithium concentrate grades from all parts of
the deposit, a variability test work programme was conducted to
assess the metallurgical performance of various lithologies,
lithium grades and weathering states. The 'whole-of-ore' laboratory
bench scale flotation test work results, on the fresh and
transitional Grandao variability samples tested, excluding the
transitional aplite sample (which represents less than 3% of the
deposit), indicates lithia (Li(2) O) recoveries and concentrate
grades of:
o 76% recovery and 6% concentrate grades for the fresh
samples
o 74% recovery and 6% concentrate grades for the transitional
samples
Pinheiro & Aldeia deposits:
-- Preliminary metallurgical whole of ore float tests on both
deposits confirm the potential to produce saleable concentrate
grades
-- Testing, which is yet to be optimised, produced concentrates
grades of up to 6.1% Li(2) O, with recoveries in excess of 77% at
Pinheiro and 5.5% Li(2) O, with recoveries in excess of 73% at
Aldeia
Conclusions & Next steps:
-- Geometallurgical modelling highlighted that c.93% of the
global Mineral Resources for the Project are considered fresh
mineralisation
-- The predominance of fresh mineralisation provides a
significant advantage to the Project as it would allow bulk mining
techniques to be used, which limits dilution or contamination
-- The lithium concentrates produced from all deposits have low
iron and impurity levels making for a very saleable concentrate
-- Significant scope remains to further optimise and improve
upon these results which Savannah is doing through its ongoing
metallurgical test work programmes - further results will be
announced as they become available.
Savannah's CEO, David Archer said: "These are excellent results
which validate the application of the recently defined,
"whole-of-ore" flotation circuit to the Grandao, Pinheiro and
Aldeia deposits at the Mina do Barroso Lithium Project. They are
broadly consistent with the recovery and grade assumptions in last
year's Scoping Study of 80% recoveries and 6% Li O grades in the
concentrate. The Scoping Study results were based on the then
preferred flow sheet of initial concentration by Dense Media
Separation followed by flotation. However, the subsequent
Definitive Feasibility Study test work has shown that
"whole-of-ore" float has the potential to provide the best overall
economic outcomes for the Project. Additionally, the current work
resulted in low levels of the iron, potassium and sodium making for
a very saleable concentrate.
"We have put an enormous amount of effort into validating the
new flow sheet. While flotation is a venerable processing technique
in the mining industry, we have sought to ensure the application of
the technique to Mina do Barroso spodumene mineralisation is
optimised. The work was designed to test the performance of the
flow sheet with different weathering states of the mineralisation,
dealing with the presence of micas and to test the performance from
lower grade lithium mineralisation. Our results vindicate the extra
time and investment we have put into the metallurgical test work
programmes, which will now continue, culminating in a final stage
of pilot plant scale testing."
Test work Overview
Details of the test work programme are detailed in Appendix
A.
Further Work
Following the robust results from the Grandao "whole-of-ore"
laboratory programme, flotation work will now focus on final
process flowsheet refinements prior to pilot plant test work.
The results produced from these preliminary tests on both
Pinheiro and Aldeia have demonstrated that commercially acceptable
grades and recoveries can be generated using a standard flotation
process. Optimisation and variability testing are ongoing as
further samples become available.
Savannah is progressing the metallurgical test programme at
laboratory scale to focus on the following:
-- Screening new reagents to improve the recoveries and concentrate grades
-- To test the variability
-- To achieve further optimisation by doing locked cycle testing
-- To test the recovery of acceptable feldspar and quartz concentrates
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 Limited. Mr Ferguson is a
Member of the Australasian Institute of Mining and Metallurgy
(AusIMM) 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 Noel O'Brien,
FAusIMM, MBA, B. Met Eng. Mr O'Brien is not an employee of the
Company but is employed as a contract consultant. Mr O'Brien is a
Fellow of the Australasian Institute of Mining and Metallurgy and
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" (The JORC Code). Mr
O'Brien 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 Article 7 of Regulation (EU) 596/2014.
**S**
David Archer Savannah Resources Tel: +44 20 7117 2489
plc
David Hignell / Charlie SP Angel Corporate Tel: +44 20 3470 0470
Bouverat (Nominated Adviser) Finance LLP
Christopher Raggett (Joint finnCap Ltd Tel: +44 20 7220 0500
Broker)
Grant Barker (Joint Broker) Whitman Howard Tel: +44 20 7659 1225
Isabel de Salis / Cosima St Brides Partners Tel: +44 20 7236 1177
Akerman (Financial PR) Ltd
For further information please visit www.savannahresources.com
or contact:
About Savannah
Savannah is a diversified resources group (AIM: SAV) with a
portfolio of energy metals projects - lithium in Portugal and
copper in Oman - together with the world-class Mutamba Heavy
Mineral Sands Project in Mozambique, which is being developed in a
consortium with the global major Rio Tinto. The Board is committed
to serving the interests of its shareholders and to delivering
outcomes that will improve the lives of the communities we work
with and our staff.
The Company is listed and regulated on AIM and the Company's
ordinary shares are also available on the Quotation Board of the
Frankfurt Stock Exchange (FWB) under the symbol FWB: SAV, and the
Börse Stuttgart (SWB) under the ticker "SAV".
APPIX A
Test Work Overview
Savannah has successfully produced good quality spodumene
concentrates from all of the Grandao, Pinheiro and Aldeia deposits,
using a "whole of ore flotation" process developed during the
previous test work programmes.
Grandao
277 diamond drill core bagged samples, from the Grandao deposit,
Mina do Barroso Project, were provided as whole cores. Each
supplied bagged core section was crushed at 19 mm with a sub--split
taken for head assay to avoid assay variation from twin hole assay
data (Geology drill hole database) prior to compositing.
The samples were composited based on assay data and geological
logging descriptions on the material type and degree of
oxidation/weathering profile. Samples were typically selected along
contiguous drill hole intercepts, and also with some edge material
included. The head assay data and geology descriptions for the
composite samples is summarised in Table 1, with the samples sorted
by weathering profile.
Table 1. Grandao Head Assay and Sample Summary Table
Composite Hole ID From To Sample Li(2) Fe(2) Na(2) K(2) Description
ID (m) (m) Mass O O(3) O O
(kg) (%) (%) (%) (%)
Fresh with 12%
schist, mixture
of banded and
GRA-M009 18GRADD021/22/28 38.0 47.0 81 1.24 1.15 3.30 3.21 pegmatite
--------------------- ----- ------ ------- ------ ------ ------ ----- ---------------------
all Fresh, 85%
banded and rest
GRA-M010 18GRADD022/28 47.9 70.0 96 1.04 0.42 4.63 2.60 pegmatite
--------------------- ----- ------ ------- ------ ------ ------ ----- ---------------------
55% Fresh, primarily
pegmatite with
30% aplite and
GRA-M012 18GRADD020/28 47.0 63.7 75 0.88 0.35 4.35 2.86 banded
--------------------- ----- ------ ------- ------ ------ ------ ----- ---------------------
Mixture (60%)
Fresh with a higher
(20%) of schist,
GRA-M016 18GRADD020/22/28 45.0 62.0 78 1.26 1.62 3.33 2.73 rest pegmatite
--------------------- ----- ------ ------- ------ ------ ------ ----- ---------------------
all Transitional,
GRA-M007 18GRADD008/23 24.0 53.2 81 0.82 1.02 3.90 3.26 all pegmatite
--------------------- ----- ------ ------- ------ ------ ------ ----- ---------------------
all Transitional,
mixture of banded
GRA-M008 18GRADD020/21/28 10.0 60.0 93 1.28 0.29 4.14 2.39 and pegmatite
--------------------- ----- ------ ------- ------ ------ ------ ----- ---------------------
all Transitional,
GRA-M011 18GRADD019/23 18.7 24.7 84 0.96 0.33 3.81 2.84 all pegmatite
--------------------- ----- ------ ------- ------ ------ ------ ----- ---------------------
GRA-M014 18GRADD019/23/25 6.1 29.0 91 0.79 0.39 4.57 2.83 Banded Transitional
--------------------- ----- ------ ------- ------ ------ ------ ----- ---------------------
GRA-M013 18GRADD019/20/25/28 11.2 43.5 56 0.79 0.38 4.58 2.67 Aplite Transitional
--------------------- ----- ------ ------- ------ ------ ------ ----- ---------------------
all Transitional,
primarily pegmatite
with <10% each
GRA-M015 18GRADD008/19/23/25 0.5 50.35 72 0.76 0.50 4.53 2.82 aplite and banded
--------------------- ----- ------ ------- ------ ------ ------ ----- ---------------------
'Whole of ore' laboratory bench scale flotation tests were
performed on each of the composited Grandao variability samples,
and test work conditions comprised:
-- Grind to P(80) 106 um
-- Deslime (at P(80) 20 um),
-- Wet high intensity magnetic separation
-- Rougher mica pre-float
-- Rougher/cleaner/re-cleaner stage spodumene flotation,
The 'whole-of-ore' laboratory bench scale flotation test work
results, for the combined spodumene re-cleaner 1 to 3 concentrates,
are presented in Table 2.
Table 2: Global Summary of Spodumene Re-Cleaner Flotation (Con
1-3), Grandao Composites
Composite Mass* Li(2) Li(2) Fe(2) Na(2) K(2) LOI(1000) Description
ID Deport. O* Deport. O O(3) O (%) O (%)**
(%) (%) (%) (%) (%)
Fresh, 10%
GRA-M009 15.1% 79.3% 6.60 0.66 0.41 0.46 1.25 schist
--------- ------------ ------ ------ ------- ----- ---------- -------------
GRA-M010 13.6% 79.1% 5.86 0.44 0.83 1.00 1.61 Fresh
--------- ------------ ------ ------ ------- ----- ---------- -------------
GRA-M012 11.7% 79.3% 6.13 0.38 0.63 0.56 1.53 Fresh
--------- ------------ ------ ------ ------- ----- ---------- -------------
Fresh, 20%
GRA-M016 13.8% 74.9% 5.89 0.72 0.57 0.63 1.51 schist
--------- ------------ ------ ------ ------- ----- ---------- -------------
GRA-M007 9.7% 65.4% 6.23 0.88 0.56 0.48 1.55 Transitional
--------- ------------ ------ ------ ------- ----- ---------- -------------
GRA-M008 14.9% 80.8% 6.57 0.38 0.66 0.61 1.26 Transitional
--------- ------------ ------ ------ ------- ----- ---------- -------------
GRA-M011 10.0% 63.7% 5.87 0.54 0.83 0.65 1.84 Transitional
--------- ------------ ------ ------ ------- ----- ---------- -------------
GRA-M014 9.1% 69.6% 6.13 0.61 0.63 0.71 1.63 Transitional
--------- ------------ ------ ------ ------- ----- ---------- -------------
Transitional
GRA-M013 11.5% 73.3% 5.15 0.54 1.24 0.81 1.64 / Aplite
--------- ------------ ------ ------ ------- ----- ---------- -------------
Transitional
GRA-M015 10.1% 71.4% 5.25 0.47 1.36 0.60 1.73 / Aplite
--------- ------------ ------ ------ ------- ----- ---------- -------------
* Global deportment
**LOI = Loss on Ignition (Moisture)
The lithia flotation kinetic grade and recovery curves for each
Grandao composite sample are illustrated in Figure 1, with the
samples sorted on the material type and degree of
oxidation/weathering profile.
Figure 1: Spodumene Flotation Concentrate Grade and Recovery
Curves, Grandao Composites
-- The fresh and transitional Grandao variability samples
assessed in this work produced a 6.0% Li(2) O concentrate grade via
the 'whole-of-ore' flotation process flowsheet.
-- The summarised flotation concentrate data, extrapolated at a
6.0% Li(2) O concentrate grade on the fresh and transitional
Grandao variability samples tested, indicates lithia recoveries
of:
o 72% - 80% for the fresh samples
o 66% - 83% for the transitional samples, excluding the
transitional aplite sample which represents less than 3% of the
deposit
-- Circa 80% to 90% of the iron was removed in the three stages
of feed preparation prior to spodumene flotation - via desliming,
magnetic separation and mica removal via flotation.
-- Spodumene flotation concentrate produced in this work, and
ranging between 5.5% to 6.0% Li(2) O, contained less than 1% Fe(2)
O(3) in all cases.
-- At a flotation concentrate grade of 6.0% Li(2) O, the halide
content was less than 1.0% Na(2) O and 1.0% K(2) O in the fresh and
transitional samples.
-- At a flotation concentrate grade of 5.5% Li(2) O, the halide
content was less than 1.3% Na(2) O and 1.1% K(2) O in all samples
(fresh, transitional and transitional/aplite).
Pinheiro
Two samples (Table 3) from the Pinheiro deposit were subjected
to standard metallurgical tests to enable evaluation of the
potential final products.
Table 3. Pinheiro Head Assay and Sample Summary Table
Composite Hole ID From To Sample Li(2) Fe(2) Na(2) K(2) LOI(1000) Description
ID (m) (m) Mass O O(3) O (%) O (%) (%)
(kg) (%) (%)
Fresh pegmatite
PNR - with 10%
M001 18PNRDD001 15.10 22.50 73 1.29 0.65 3.41 2.65 0.96 schist
------------ ------ ------ ------- ------ ------ ------- ------- ---------- ----------------
PNR -
M004 18PNRDD002 39.00 50.25 103 1.12 0.62 3.36 2.84 1.41 Transitional
------------ ------ ------ ------- ------ ------ ------- ------- ---------- ----------------
'Whole of ore' laboratory scale flotation test work was
performed on the Pinheiro samples, using standard conditions:
-- Grind to P80 106 um
-- Deslime (at P80 20 um), followed by wet high intensity magnetic separation
-- Rougher/cleaner mica pre-float
-- Rougher and single cleaner stage spodumene flotation
The influence of collector type was also investigated:
-- Alternative spodumene collector, Clariant Flotinor 7801, with 750 g/t dosage
-- Oleic acid, a common monounsaturated fat in the human diet, with 2400 g/t dosage
The high-level summary of spodumene flotation concentrate
produced from this suite of tests is presented in Table 4 and
Figure 2.
Table 4: Global Summary of Spodumene Flotation, Pinheiro
Composites
Composite Mass Deport. Li(2) Li(2) Fe(2) Na(2) K(2) O LOI(1000)
ID (%) O Deport. O (%) O(3) (%) O (%) (%) (%)
(%)
PNR - M001* 13.2 56.3 5.36 0.71 0.71 0.86 0.99
------------- ----------- ------- ---------- ------- ------- ----------
PNR - M004** 13.6 77.2 6.08 0.43 0.60 0.37 0.83
------------- ----------- ------- ---------- ------- ------- ----------
*Spodumene rougher concentrate grade, 2400 g/t oleic acid,
**Spodumene Re-cleaner 1-2 Concentrate, 750 g/t Flotinor 7801
**LOI = Loss on ignition (moisture)
The results produced by the flotation conditions for PNRM004
produced the best results of 6.1% Li(2) O at 77% recoveries and
further test work will focus on other samples from the Project
using these flotation conditions and looking to further optimise
and improve the flotation performance.
Aldeia
Two samples (Table 3) from the Aldeia deposit were subjected to
standard metallurgical tests to enable evaluation of the potential
final products.
Table 5. Aldeia Composite Head Assay and Sample Summary
Table
Composite Hole ID From To Sample Li(2) Fe(2) Na(2) K(2) LOI(1000) Description
ID (m) (m) Mass O (%) O(3) O O (%)
(kg) (%) (%) (%)
75% Fresh with
oxides on fractures,
ALD-M005 19ALADD001 5.65 23.50 117 0.84 1.26 3.05 3.02 1.56 25% schist material
------------ ------ ------ ------- ------- ------ ------ ----- ---------- ----------------------
25% Fresh, 75%
Fresh with oxides
ALD-M006 19ALADD003 23.00 36.00 113 1.10 0.81 3.70 3.14 1.06 on fractures
------------ ------ ------ ------- ------- ------ ------ ----- ---------- ----------------------
'Whole of ore' laboratory bench scale flotation test work was
performed on the Aldeia composite samples (Table 5), and
preliminary conditions comprised:
-- Grind to P80 106 um
-- Deslime (at P80 20 um), followed by wet high intensity magnetic separation
-- Rougher mica pre-float
-- Rougher/cleaner/re-cleaner stage spodumene flotation
The laboratory bench scale re-cleaner flotation test work
results for the Aldeia composites are summarised in Table 6 and
Figure 3.
Table 6: Global Summary of Spodumene Flotation, Aldeia
Composites
Composite Mass Deport. Li(2) O Li(2) O Fe(2) O(3) Na(2) O K(2) O LOI(1000)
ID (%) Deport. (%) (%) (%) (%) (%)
(%)
ALD-M005 8.6 53.9 5.56 0.85 0.65 0.85 2.67
------------- --------- -------- ----------- -------- ------- ----------
ALD-M006 12.9 68.4 5.55 0.78 0.47 1.81 2.38
------------- --------- -------- ----------- -------- ------- ----------
Figure 2. Spodumene Re-Cleaner Flotation Performance, Aldeia
Composites
Further development test work is now required to optimise and
improve the Aldeia flotation performance.
Geometallurgy
A detailed geometallurgical model for each deposit is under
construction to ensure that the Company has a thorough
understanding of how each deposit is likely to perform when
processed. As part of the variability test work, samples from each
rock type were processed including samples of different grade and
weathering as well as introducing up to 10% of the host schist.
This process was completed to ensure that a robust flow sheet can
be developed which can treat all rock types and produce a saleable
concentrate at acceptable recoveries.
Geometallurgical modelling has highlighted:
-- The major rock type (over 80%) in the deposits is pegmatite
which has routinely reported very good recoveries and concentrate
grades (Table 7)
-- Around 93% of the global resources for the Project are
considered fresh with only limited transitional material present
(Table 8)
-- The geometallurgical model has highlighted the distribution
of the transitional material where metallurgical performance is
more variable than in the fresh material - having a strong
understanding of the distribution of these areas will enable
optimal mine scheduling to maximise recoveries and cash flows and
to reduce metallurgical risk.
-- A significant advantage of the Project is the predominance of
fresh rock type which means bulk mining can be done which limits
dilution or contamination
Table 7. May 2019 Resource Summary Based on Rock Type
Rock Type Mineralisation Minimum Li(2) Maximum Li(2) Average Li(2)
% 0% 0% 0%
FGP 80.6 0.50 3.19 1.23
--------------- -------------- -------------- --------------
FGB 5.65 0.03 2.95 0.94
--------------- -------------- -------------- --------------
FGA 3.75 0.03 1.91 0.53
--------------- -------------- -------------- --------------
SCH 10.0 0.00 1.91 0.53
--------------- -------------- -------------- --------------
100.0
--------------- -------------- -------------- --------------
FGP = Pegmatite, FGB = Banded Pegmatite/Aplite, FGA = Aplite,
SCH=Schist
Table 8. May 2019 Resource Summary Based on Weathering Types
Deposit Total (t) Fresh (t) Fresh (%) Transitional Transitional
(t) (%)
Grandao 17,739,100 16,288,200 91 1,450,900 9
----------- ----------- ---------- ------------- -------------
Pinheiro 1,958,600 1,845,000 94 113,600 6
----------- ----------- ---------- ------------- -------------
Reservatorio 3,190,100 2,940,800 98 250,100 9
----------- ----------- ---------- ------------- -------------
Aldeia 3,468,900 3,465,500 >99 3400 <0
----------- ----------- ---------- ------------- -------------
NOA 640,600 574,500 88 66,100 12
----------- ----------- ---------- ------------- -------------
Total 26,997,300 25,113,200 93 1,884,200 7
----------- ----------- ---------- ------------- -------------
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