Sovereign Metals Limited: Resource Upgrade: Malingunde Flake Graphite Project
(firmenpresse) - RESOURCE UPGRADE: MALINGUNDE FLAKE GRAPHITE PROJECT
Sovereign Metals Limited (the Company or Sovereign) is pleased to report the updated Mineral Resource Estimate (MRE) for the soft saprolite-hosted Malingunde Project in Malawi.
The updated MRE provides the basis for a future low capex and low opex natural flake graphite operation focused on the soft saprolite (clay)-hosted component.
Saprolite + Saprock MRE (Measured, Indicated & Inferred):
45.7Mt (at) 7.2% TGC (4.0% TGC cut-off, 81% Measured + Indicated)
including High Grade Component:
14.5Mt (at) 9.7% TGC (7.5% TGC cut-off, 88% Measured + Indicated)
Recent metallurgical test-work has confirmed that a blend of saprock can be processed along with the very soft saprolite material, enabling the Company to access additional soft mineralised material not previously considered in the 2017 Scoping Study.
HIGHLIGHTS:
- Malingunde is the worlds largest reported soft saprolite-hosted graphite Mineral Resource1.
- 81% of the total Mineral Resource (>4.0% TGC) and 88% of the high-grade (>7.5% TGC) component is now classified as Measured or Indicated.
- High-grade component of 14.5Mt (at) 9.7% TGC (saprolite + saprock) to provide the focus for the Malingunde PFS; a significant increase in tonnage driven primarily by inclusion of saprock material.
- Metallurgical test-work confirms that the blended saprolite (~85%) and saprock (~15%) material does not require primary crushing or grinding, providing the potential for substantially reduced processing costs compared to hard rock deposits.
- All planned mining inventory is within 35m of surface and will be free-digging with very low strip ratios, with the potential for very low mining costs.
Dr Julian Stephens, Sovereigns Managing Director commented, The ability to process a blend of saprock along with the very soft saprolite allows a ~60% increase in high-grade, low-cost material that Sovereign will consider as part of the Malingunde PFS. With this exceptional resource base, the Company will now progress rapid completion of the PFS, leveraging the projects inherent low opex and high margin potential.
ENQUIRIES ---Dr Julian Stephens - Managing Director
+618 9322 6322--Dominic Allen - Business Development Manager
MINERAL RESOURCE ESTIMATE TABLES
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Table 1. Summary of 2018 Malingunde JORC Mineral Resource Estimate (Malingunde + Msinja deposits) at 4.0% and 7.5% TGC cut-off grades.
INTRODUCTION
Saprolite-hosted graphite deposits are sought after as they generally have lower capex requirements and low operating costs compared to hard rock graphite mines. Sovereign explored the Malingunde area in 2015 and 2016, resulting in the discovery of the worlds largest reported saprolite-hosted graphite Mineral Resource reported in the maiden JORC MRE in 2017. An additional ~6,000m of aircore drilling in 2017 was undertaken primarily in order to upgrade the Mineral Resource categories.
The global MRE also includes Mineral Resources from the newly discovered Msinja deposit, some 1.5km along strike to the south-east of main Malingunde deposit.
Features of the Malingunde MRE include:
- A high-grade core (at) ~10% TGC which forms the focus for the upcoming PFS;
- Very soft, free-digging material for the life of mine and a very low strip ratio will equate to very low mining costs;
- No requirement for primary crushing and grinding, significantly reducing capital requirements and operating costs;
- Proximity to Malawis capital means access to existing infrastructure - rail, water, power & labour;
- Premium graphite products in terms of flake sizes and concentrate grades will equate attractive concentrate pricing.
Malingunde has the potential to be a world-class asset with the potential for low capital requirements, low operating costs and high revenues per tonne of concentrate, likely resulting in a high margin operation.
MINERAL RESOURCE ESTIMATE
The updated, 2018 Malingunde Mineral Resource Estimate was undertaken by CSA Global and is reported in accordance with the JORC Code (2012 Edition).
The high-grade saprolite and saprock component of 14.5Mt (at) 9.70% TGC all occurs within 35m of the natural ground surface. The upcoming PFS is focused on this the high-grade saprolite and saprock component.
The Competent Person and Sovereign believe there are reasonable prospects for eventual economic extraction of the Mineral Resource. Consideration was given to the relatively shallow and soft nature of the mineralisation making it amenable to free-dig open pit mining, existing infrastructure near to the project, including rail, power, labour and water. Metallurgical test-work carried out to date on flake size distribution and purity are considered by the Competent Person and the Company to be favourable for product marketability.
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Figure 1. Cross-section 8,437,000mN showing MRE blocks and with TGC grade ranges
SUMMARY OF RESOURCE ESTIMATE AND REPORTING CRITERIA
The following is a summary of the pertinent information used in the Mineral Resource Estimate with full details provided in the JORC Code Table 1 included as Appendix 2.
Geology and Geological Interpretation
The Malingunde Deposit comprises ~4,500 m strike length of shallowly north-east dipping, north-west striking graphitic gneisses. The mineralised package has up to six separate sub-parallel zones of graphite gneiss with cumulative across strike widths averaging 120 m and locally exceeding 200 m. The Msinja Deposit has a strike length of approximately 1,000 m with about five parallel zones of mineralisation. Across strike, cumulative widths range between 40 and 100 m.
Malingunde occurs in a topographically flat area west of Malawis capital known as the Lilongwe Plain and a deep tropical weathering profile is preserved. A typical profile from top to base is generally soil (SOIL, 0-1m), ferruginous pedolith (FERP, 1-4m), mottled zone (MOTT, 4-7m), pallid saprolite (PSAP, 7-9m), saprolite (SAPL, 9-25m), saprock (SAPR, 25-35m) and fresh rock (FRESH >35m). For the purposes of the MRE, all units from saprolite and above are included under the heading saprolite, with all weathering types within the saprolite being soft and expected to be free-dig during open-pit mining.
Drilling and Sampling Techniques
The MRE is based upon data obtained from 13 diamond core (DD) drill holes (487.75 m), 384 aircore (AC) holes (11,595.8 m) and 1,053 hand auger (HA) holes (10,686 m) drilled across the Malingunde and Msinja deposits. Five (5) pairs of AC/DD and eight (8) pairs of AC/HA twinned holes are included in the drilling totals. Drilling occurred during 2016 and 2017.
HA and AC holes are located on east-west transects across the entire strike of the modelled deposit spaced nominally at 100 m x 20 m with infill of 50 m (N) x 20 m (E) over a section of the northern area of the Malingunde deposit. DD holes were drilled on existing drill sections and spaced between 200 m and 400 m north-south along the strike extent of the deposit. All HA holes were drilled vertically whilst the majority of the AC and DD holes were angled, designed to intersect broadly orthogonal to the shallow-moderate east dipping mineralisation.
The drill hole collars were surveyed using a differential global positioning system (DGPS) to centimetre accuracy. All DD holes were down-hole surveyed using a Reflex Ez-Trak multi-shot survey tool at 30m intervals down hole. Owing to their shallow depths (maximum 12 m), HA holes were not downhole surveyed. AC holes were not routinely down-hole surveyed, however 23 holes (5%) were surveyed to verify the amount of downhole deviation.
HA and AC drill samples were geologically logged, recording relevant data to a set template at 1 m intervals. DD core was geologically logged based on geological intervals. DD core was also geotechnically logged and digitally photographed.
DD core (PQ3) was quarter cut and sampled according to geological intervals. HA samples were composited on geological intervals of between 2-3 m during the 2016 field season, and 1 m intervals in 2017 and submitted for Total Graphitic Carbon (TGC) analysis. AC samples were sampled at 1 m and 2 m intervals. Field quality assurance procedures were employed, including the use of analytical standards, coarse blanks and duplicates.
Sample Analysis Method
Samples were shipped to Intertek sample preparation laboratory in Johannesburg or Perth. Upon receipt of the sample, the laboratory prepared ~100g pulp samples for shipment (in the case of Johannesburg) to Intertek Perth where they were analysed. A 0.2g charge is analysed for TGC using an Eltra carbon analyser resistance furnace.
Classification Criteria
Classification of the MRE was carried out taking into account the geological understanding of the deposit, quality of the samples, bulk density data and drill hole spacing, supported by metallurgical test results that indicate general product marketability.
The Malingunde MRE is classified as a combination of Measured, Indicated and Inferred, with geological evidence sufficient to confirm geological and grade continuity in the Measured volumes. The Measured Mineral Resource is confined to the saprolite profile. Where the saprock profile is located beneath saprolite classified as Measured, the saprock is classified as Indicated due to fewer drill samples derived from the saprock. The top 10 m of the fresh rock zone is classified as Inferred due to the sparsely spaced drilling, although DD samples were obtained from the fresh rock.
The Malingunde MRE is classified as Measured where drill spacing of 50 m (N) by 20 m (E) supports the geological interpretation and grade interpolation. Eight DD holes were drilled within the Measured footprint and provided detailed geological information as well as samples for metallurgical testwork. Drill spacing of 100 m (N) by 20 m (E) supports the Indicated classification, whilst drill spacing of 200 m (N) by 20 m (E) to 200 m (N) by 50 m (E) supports the Inferred classification.
The Msinja MRE is classified as Inferred, with no metallurgical test-work or diamond drilling conducted to date at Msinja. Blocks in the fresh rock domain are unclassified because no samples have been obtained to date from the fresh rock zone. No density data has been obtained from Msinja samples. The geological setting of Msinja is identical to Malingunde and therefore the use of Malingundes density and metallurgical data is justified when estimating the Msinja MRE. Drill spacing at Msinja supporting the Inferred classification ranges from 100 m (N) by 20 m (E) to 200 m (N) by 20 m (E).
All available data was assessed and the Competent Persons relative confidence in the data was used to assist in the classification of the Mineral Resource.
Resource Estimation Methodology
TGC wireframe interpretations were based upon a lower cut-off of 4% TGC, which is equivalent to the graphitic gneiss domain boundary, from geological logging of HA/AC/DD drill holes.
The MRE block model consists of 6 zones of TGC mineralisation in the Malingunde deposit, and 5 in the Msinja deposit. Mineralisation domains were encapsulated by means of 3D wireframed envelopes based upon a lower cut-off grade of 4% TGC. Weathering domains were interpreted based upon geological logs of drill samples. Domains were extrapolated along strike or down plunge to half a section spacing. Internal waste units were modelled within the graphitic gneiss mineralisation envelopes to define barren domains.
All drill hole assay samples were composited to 2 m intervals. All assayed HA/AC/DD drill hole intervals were utilised in the grade interpolation.
Top cutting of composited sample assays was applied to constrain extreme grade values when warranted. Top cuts were determined by reviewing histograms and log probability plots of domained assays, and iterative calculations of mean domain TGC grades, testing a range of top cuts. All top cuts were applied to data in the 99th percentile of data. Variograms were modelled from composited data within the most populated domain, with a relative nugget of 33% and short range of 33 m, which accommodates 73% of the population variance. The principal variogram direction is in a shallow plunge along strike to the north.
Grade estimation was by ordinary kriging (OK). A minimum of 12 and maximum of 28 composited samples were used in any one block estimate for all domains. A maximum of 6 composited samples per drill hole were used in any one block estimate. No hard boundary domains within the mineralisation domains were used, with all data across the weathering and fresh rock profiles available to support all block estimates per domain. Each mineralisation domain acted as a hard domain boundary such that a composited drill assay in one domain could not interpolate a block grade in an adjacent domain.
The grade model was validated by 1) creating slices of the model and comparing to drill hole samples on the same slice; 2) swath plots comparing average block grades with average sample grades on nominated easting, northing and RL slices; 3) mean grades per domain for estimated blocks and flagged drill hole samples; and 4) cross sections with block model and drill hole data colour coded in like manner.
Cut-off Grades
The MRE has been reported using lower cut-off grade of 4.0% and 7.5% TGC, which is consistent with the grade used to report the previous MRE. The 4.0% lower cut-off grade was selected as it represents a natural geological break in the data, and a figure just above a break-even grade estimated in the 2017 Scoping Study. The 7.5% cut-off grade was arbitrarily chosen in order to provide >15 years of potential feed grading circa 10% TGC.
Mining and Metallurgical Methods and Parameters
No selective mining units were assumed in this resource model. No depletion of the Mineral Resource due to mining activity was required due to no mining having occurred historically.
Sovereign announced metallurgical results to the ASX on a number of occasions between 2016 and 2018, relating to flake size distribution and purity of graphite concentrate. Metallurgical testwork is ongoing as part of the Prefeasibility Study.
Metallurgical data previously reported in 2017, plus new data generated in 2018, support the Mineral Resource classification. The flotation testwork on auger and diamond drill core samples demonstrated that approximately 50-80% of the liberated flakes are larger than 150 m (100 mesh), and that final overall concentrate grades are in the range of approximately 96-99% Carbon for all weathering domains. The conventional flotation process produced flake graphite concentrates of acceptable quality, potentially for markets such as spherical graphite, expandable graphite, graphite foil, brake lining pads, lubrication and refractories. Performance tests verified that Malingunde graphite concentrates should meet or exceed the specifications for expandable graphite.
The available process testwork in conjunction with drill sample observations from the remainder of the deposit supports the classification of the Malingunde deposit as an Industrial Mineral Resource in terms of the JORC Code Clause 49.
Competent Person Statement
The information that relates to Mineral Resources is based on, and fairly represents, information compiled by Mr David Williams, a Competent Person, who is a Member of The Australian Institute of Geoscientists. Mr Williams is employed by CSA Global Pty Ltd, an independent consulting company. Mr Williams has sufficient experience, which is relevant to the style of mineralisation and type of deposit under consideration, and to the activity he is undertaking, to qualify as a Competent Person as defined in the 2012 Edition of the Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves. Mr Williams consents to the inclusion of the matters based on his information in the form and context in which it appears.
The information that relates to Exploration Results is extracted from announcements on 29 August 2016, 12 October 2016, 26 November 2016, 18 January 2017, 21 February 2017, 15 March 2017, 17 January 2018, 18 February 2018, 19 March 2018 and 3 April 2018. These announcements are available to view on www.sovereignmetals.com.au. The information in the original announcements that related to Exploration Results were based on, and fairly represents, information compiled by Dr Julian Stephens, a Competent Person who is a member of the Australasian Institute of Geoscientists (AIG). Dr Stephens is the Managing Director of Sovereign Metals Limited and a holder of shares, options and performance rights in Sovereign Metals Limited. Dr Stephens has sufficient experience that is relevant to the style of mineralisation and type of deposit under consideration and to the activity being undertaken, to qualify as a Competent Person as defined in the 2012 Edition of the 'Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves'. The Company confirms that it is not aware of any new information or data that materially affects the information included in the original market announcements. The Company confirms that the form and context in which the Competent Persons findings are presented have not been materially modified from the original market announcements.
Forward Looking Statement
This release may include forward-looking statements, which may be identified by words such as "expects", "anticipates", "believes", "projects", "plans", and similar expressions. These forward-looking statements are based on Sovereigns expectations and beliefs concerning future events. Forward looking statements are necessarily subject to risks, uncertainties and other factors, many of which are outside the control of Sovereign, which could cause actual results to differ materially from such statements. There can be no assurance that forward-looking statements will prove to be correct. Sovereign makes no undertaking to subsequently update or revise the forward-looking statements made in this release, to reflect the circumstances or events after the date of that release.
Footnote 1
The Malingunde Mineral Resource is understood by the Company to be the largest known saprolite-hosted flake graphite deposit in the world that has been reported under recognised western Mineral Resource reporting codes (i.e. JORC, NI 43-101, SAMREC).
Appendix 1: Mineral Resource Tables
Mineral Resource statement, Malingunde and Msinja. TGC>4.0%
Tonnes (Mt)* TGC (%)
Malingunde Measured 4.8 8.5
Indicated 32.3 7.2
Inferred 20.6 7.3
Sub-total 57.7 7.4
Msinja Measured - -
Indicated - -
Inferred 7.3 6.2
Sub-total 7.3 6.2
All Measured 4.8 8.5
Indicated 32.3 7.2
Inferred 27.9 7.0
All Total 65.0 7.2
* Tonnages rounded to the nearest Mt. Differences may occur in totals due to rounding
Mineral Resource statement, Malingunde and Msinja. TGC>7.5%
Tonnes (Mt)* TGC (%)
Malingunde Measured 2.7 10.0
Indicated 10.1 9.8
Inferred 6.9 9.8
Sub-total 19.7 9.8
Msinja Measured - -
Indicated - -
Inferred 1.4 9.2
Sub-total 1.4 9.2
All Measured 2.7 10.0
Indicated 10.1 9.8
Inferred 8.3 9.7
All Total 21.0 9.8
* Tonnages rounded to the nearest Mt. Differences may occur in totals due to rounding
Mineral Resource statement, Malingunde and Msinja, by
Weathering Profile.
TGC>4.0%
Tonnes (Mt)* TGC (%)
Saprolite Measured 4.8 8.5
Indicated 18.7 7.1
Inferred 5.4 6.3
Sub-total 28.8 7.2
Saprock Measured - -
Indicated 13.6 7.4
Inferred 3.3 6.3
Sub-total 16.9 7.2
Fresh Measured - -
Indicated - -
Inferred 19.3 7.3
Total 19.3 7.3
Total Measured 4.8 8.5
Indicated 32.3 7.2
Inferred 27.9 7.0
Total 65.0 7.2
*Tonnages rounded to the nearest Mt. Differences may occur in totals due to rounding. Saprolite is defined as a combination of the SOIL, FERP, MOTT, PSAP and SAPL weathering domains, as discussed later in this document.
Mineral Resource statement, Malingunde and Msinja, by
Weathering Profile.
TGC>7.5%
Tonnes (Mt)* TGC (%)
Saprolite Measured 2.7 10.0
Indicated 5.4 9.6
Inferred 1.1 9.0
Sub-total 9.2 9.7
Saprock Measured - -
Indicated 4.7 10.0
Inferred 0.6 9.1
Sub-total 5.3 9.9
Fresh Measured - -
Indicated - -
Inferred 6.5 9.9
Total 6.5 9.9
Total Measured 2.7 10.0
Indicated 10.1 9.8
Inferred 8.3 9.7
Total 21.0 9.8
*Tonnages rounded to the nearest Mt. Differences may occur in totals due to rounding. Saprolite is defined as a combination of the SOIL, FERP, MOTT, PSAP and SAPL weathering domains, as discussed later in this document.
Appendix 2: JORC Code, 2012 Edition - Table 1
Section 1 Sampling Techniques and Data
Criter JORC Code Commentary
ia explanation
SampliNature and Hand Auger (HA), Air-core (AC) and
ng quality of Diamond core (DD) drilling form the
Techn sampling (e.g. basis of the Mineral Resource
iques cut channels, Estimate (MRE) and are described
random chips, below:
or specific
specialised HA drilling was employed to obtain
industry samples vertically
standard
measurement from surface at nominal 1-metre depth
tools intervals, with
appropriate to
the minerals samples composited on geologically
under determined intervals. Composite
investigation, samples were riffle split on
such as down site.
hole gamma A total of 1,053 HA holes (10,686 m)
sondes, or support the
handheld XRF MRE.
instruments,
etc.). These AC drilling was employed to obtain
examples should bulk drill cuttings at nominal
not be taken as 1-metre (downhole) intervals from
limiting the surface. All 1-metre samples were
broad meaning collected in plastic bags directly
of beneath the drilling rig cyclone
sampling. underflow. The entire 1-metre sample
was manually split using either a
3-tier (87.5:12.5 split) or single
tier (50:50 split) riffle splitter or
a combination thereof to facilitate
the mass reduction of a laboratory
assay split. Compositing of the
laboratory sample split was performed
on a geological basis. Mineralised
(>=3% v/v visual) laboratory splits
of 1-metre intervals from surface to
the top of the
saprolite zone were not composited
whereas mineralised splits of the
underlying
saprolite and saprock intervals were
composited nominally at 2-metres.
Unmineralised (=<3% v/v visual),
laboratory splits of 4-metre
intervals from top of hole to bottom
of hole were
composited.
A total of 384 AC holes (11,595.8 m)
support the
MRE.
DD drilling (angled and vertical) was
designed to obtain representative
large diameter (PQ3) core for
geological, geotechnical and
metallurgical
testwork purposes. Subsequent to
completion of all geological and
geotechnical logging and sampling
(whole core samples removed
laboratory bulk density and strength
testing) drill core was either
manually hand split or sawn using a
circular saw and sampled as ¼ PQ3
core. Upon completion of laboratory
bulk density and strength testing of
the whole core intervals the entire
core was submitted to the laboratory.
A total of 13 DD holes (487.75 m)
support the
MRE.
Laboratory splits were submitted
Intertek Perth for assay sample
preparation. Total Graphitic Carbon
(TGC) analysis of all assay pulps
samples was undertaken by Intertek
Perth.
Include Drilling and sampling activities were
reference to supervised by a suitably qualified
measures taken Company geologist who was present at
to ensure the drill rig at all times. All bulk
sample 1-metre drill samples were
geologically logged by the geologist
representivity an at the drill
d the site.
appropriate
calibration of All 1-metre downhole drill samples
any measurement collected in plastic bags from
tools or directly beneath the cyclone
systems underflow were individually weighed
used. and moisture content was
qualitatively logged prior to further
splitting and
sampling.
All mass reduction (field and
laboratory splitting) of samples were
performed within
Gys Sampling Nomogram limits relevant
to this style of
mineralisation.
Field duplicate splits were undertaken
nominally every
20
th sample to quantify sampling and
analytical error. A program of field
replicate splitting of selected (~5%)
mineralised intervals was completed
at the conclusion of the drill
program.
HA: The auger spiral and rods are
cleaned between each metre of
sampling to avoid
contamination.
AC: The sampling cyclone was routinely
cleaned out between each drill hole.
Sample recovery was quantitatively
assessed throughout the duration of
the drilling program. A program of
field replicate splitting of selected
(~5%) mineralised intervals was
completed at the conclusion of the
drill program to assess the sampling
repeatability
DD: core recovery was closely
monitored during drilling
particularly through the mineralised
zones. Standard industry drilling mud
mixtures were employed to improve
core recovery especially through the
softer upper clay rich
pedolith and saprolith horizons.
Aspects of the Flake graphite content is visually
determination estimated as volume % (% v/v) of each
of 1-metre bulk drill samples during
mineralisation geological logging by Company
that are geologist. A nominal lower cut-off of
Material to the 5% TGC assay has been applied to
Public Report. define zones of
In cases where mineralisation.
industry
standard work
has been done
this would be
relatively
simple (e.g.
reverse
circulation
drilling was
used to obtain
1 m samples
from which 3 kg
was pulverised
to produce a 30
g charge for
fire assay).
In other cases
more
explanation may
be required,
such as where
there is coarse
gold that has
inherent
sampling
problems.
Unusual
commodities or
mineralisation
types (e.g.
submarine
nodules) may
warrant
disclosure of
detailed
information.
DrilliDrill type (e.g. HA: drilling was performed manually by
ng core, reverse Sovereign employees using a
Techn circulation, conventional hand auger employing a
iques openhole combination of 62mm and 50mm diameter
hammer, rotary spiral auger flight and 1-metre long
air blast, steel rods. Each 1m of drill advance
auger, Bangka, is withdrawn and the contents of the
sonic, etc.) auger flight removed. An additional
and details 1-metre steel rod is attached and the
(e.g. core open hole is re-entered to drill the
diameter, next metre. This is repeated until
triple or the drill holes is terminated or
standard tube, reaches a maximum depth of 12m. The
depth of auger spiral and rods are cleaned
diamond tails, between each metre of sampling to
facesampling avoid contamination.
bit or other
type, whether
core is AC: conventional blade bit aircore dril
oriented and if ling was employed to obtain all drill
so, by what cuttings from surface. Drilling was
method, completed using a P900 truck mounted
etc.). rig with and separate truck mounted
air compressor. Drilling was
completed using standard 3-inch or
4-inch diameter/3m length drill rods
equipped with inner tubes. Drilling
was performed with standard face
discharge
aircore blade bits. The nominal drill h
ole
diameter for 3-inch and 4-inch holes
is 85mm and 114mm respectively. The
nominal inner tube inside diameter
for 3-inch and 4-inch holes is 37mm
and 45mm respectively. Drilling of
all 3-inch holes employed a 2-stage
compressor rated at
300CFM
:200PSI run continuously on high
stage. All 4-inch holes were drilled
employing a 2-stage compressor rated
at
900CFM
:350PSI with high-stage generally run
below about 15m downhole.
DD: conventional wireline PQ triple
tube
(PQ
3) diamond drilling (DD) was employed
to obtain all drill
core. Drilling was undertaken with an
Atlas Copco Christensen CT14 truck
mounted drilling rig. The nominal
core diameter is 83mm and the nominal
hole diameter is 122mm. Coring was
completed with appropriate diamond
impregnated tungsten carbide drilling
bits. Drill runs were completed
employing either a 1.5m or 3.0m
length
PQ
3 core barrel. Core from all drilling
runs was orientated using a Reflex
ACTIII Electronic Orientation device.
The orientation and marking of the
bottom of
hole (BOH) orientation line along the
core was completed whilst the core
was still within the drilling split.
Core was transferred from the
drilling split into PVC splits which
were then wrapped with plastic
layflat material, securely sealed and
placed into core
trays.
Drill Method of HA: sample recovery was monitored
Sampl recording and visually during removal of the sample
e assessing core from the auger
Recov and chip sample flights.
ery recoveries and
results AC: sample recovery was recorded for
assessed. all holes. The 1-metre drill samples
collected in plastic bags from
directly beneath the cyclone
underflow were individually weighed
and moisture content (dry/damp/moist
/wet/saturated) recorded prior to
further splitting and sampling. The
outside diameter of the drill bit
cutting face was measured and
recorded by the driller prior to the
commencement of each drill hole. Each
1-metre sample interval was
separately geologically logged using
standard Company project specific
logging codes. Logging of weathering
and lithology along with drill
hole diameter, recovered sample
weight, moisture content and dry bulk
density measurements of PQ diamond
core allow the theoretical sample
recovery to be assessed. Analysis of
the calculated sample recoveries
indicate an average recovery of
greater than 75% for all mineralised
(>=4% TGC)
intervals.
DD: drilling core recovery was
recorded for each drill run by
measuring the total length whilst
still in the drilling splits prior to
being transferred into core trays.
Downhole depths were validated
against core blocks and drill plods
during each shift. Holes MGDD0001,
MGDD0004 and MGDD0005 were re-drilled
due to core loss within a number of
mineralised zones. An overall core
recovery of 92% was achieved for all
sampled
core.
Measures taken HA: drill holes were terminated where
to maximise they intersected the upper (perched)
sample recovery water table (approx..
and ensure 7-8m)
representative
nature of the AC: drill bit type (face discharge)
samples. used were appropriate for the type of
formation to maximise amount of drill
cutting recovered. Drill bits were
replaced where excessive wearing of
the tungsten cutting teeth had
occurred. Adequate CFM/PSI of
compressed air was used to maximise
the drying of sample prior to
recovering up the drill string. A
number of the 2016 PQ diamond core
holes were twinned by
aircore holes to assess the representiv
ity
of AC drill samples. Where the
ingress of water in deeper sections
of holes resulted in wet samples
(usually at the
Saprolite/Saprock interface) the drill
hole was
terminated.
DD: core recovery was closely
monitored during drilling
particularly through the mineralised
zones. Standard industry drilling mud
mixtures were employed to improve
core recovery especially through the
softer upper clay rich material of
the
Pedolith and Saprolith zones. Other
measures such quantity of water,
amount of rotation and drill bit
types that are appropriate to soft
formation drilling were considered
and employed during drilling when
required. At the completion of each
drill run the steel splits containing
the core were pumped out of the
retrieved core tube. Core was then
carefully transferred from the drill
split into plastic sleeves
(
layflat) which were secured in rigid
PVC splits. The
layflat was securely bound and sealed
(to preserve moisture) with tape
prior to transferring PVC splits into
plastic core
trays.
Whether a Twin hole comparison of aircore vs
relationship hand auger and diamond core drill
exists between hole visually estimated grades
sample recovery indicates that no sample bias exists.
and grade and There does not appear to be any
whether sample relationship between
bias may have
occurred due to aircore sample recovery and TGC % v/v
preferential grade.
loss/gain of
fine/coarse
material.
LogginWhether core and All drill holes were geologically
g chip samples logged by a suitably trained Company
have been geologist using standard Company code
geologically system. Relevant data for each
and individual 1-metre sample for
geotechnically loaircore or for each geological
gged to a level interval for diamond was initially
of detail to recorded using a standard A4 paper
support template and later digitally entered
appropriate into customised Company MS Excel
Mineral spreadsheets designed with fully
Resource functional validation. Excel files
estimation are checked and loaded to MS Access
mining studies by the Database Administrator. Upon
and loading into the Access database
metallurgical further validation is performed. In
studies. addition, all
core is photographed wet and dry for
future reference.
This information is of a sufficient
level of detail to support
appropriate Mineral Resource
estimation.
Whether logging Logging is both qualitative and
is qualitative quantitative. Geological logging
or quantitative includes but is not limited to
in nature. Core lithological features, volumetric
(or costean, visual estimates of graphite content
channel, etc.) and flake
photography. characteristics.
The total length 100% of drill hole sample intervals
and percentage have been geologically
of the relevant logged.
intersection
logged
Sub-saIf core, whether Quarter PQ3 DD core is manually split
mpling cut or sawn and and/or cut using a motorised diamond
techn whether blade core saw and sampled for
iques quarter, half laboratory
or all core analysis.
and taken.
sampl
e
prepa
ration
If non-core, HA: 1-metre samples are composited on
whether geological intervals and then riffle
riffled, tube split at 50:50 using a standard Jones
sampled, rotary riffle splitter. Wet samples are
split, etc. and first air dried and then manually
whether sampled broken up prior to compositing or
wet or splitting.
dry.
AC: The entire 1-metre sample was
manually split using either a 3-tier
(87.5:12.5 split) or single tier
(50:50 split) riffle splitter or a
combination thereof to facilitate the
mass reduction of a laboratory assay
split. Compositing of the laboratory
sample split was performed on a
geological basis. Mineralised (>=3%
v/v visual) laboratory splits of
1-metre intervals from surface to the
top of the
saprolite zone were not composited
whereas mineralised splits of the
underlying
saprolite and saprock intervals were
composited nominally at 2-metres.
Unmineralised (=<3% v/v visual),
laboratory splits of 4-metre
intervals from top of hole to bottom
of hole were
composited.
All wet samples were removed from the
drill site without splitting and
relocated to the Companys premises
in Lilongwe. The wet samples were
transferred into large metal trays
and sun dried. Samples were
subsequently hand pulverised and
thoroughly homogenised prior to
splitting 50:50 with a single tier
riffle splitter. One of the
off-splits was submitted to the
laboratory for
assay.
All reject splits (i.e. the material
not sent for assaying) of each
individual 1-metre interval were
returned to original sample bag,
cable tied and placed in storage for
future
reference.
For all sample HA samples: sample preparation is
types, the conducted at Interteks laboratory in
nature, quality Johannesburg. Each entire sample is
and crushed to nominal 100% -3mm in a
appropriateness Boyd crusher then pulverised to 85%
of the sample -75µm in a LM5. Approximately 100g
preparation pulp is collected and sent to
technique. Intertek Perth for TGC
analysis.
AC samples: sample preparation was
conducted at either Intertek in Perth
or Johannesburg. The entire submitted
sample (=< ~3kg) is pulverised to 85%
-75µm in a LM5. Approximately 100g
pulp is collected and sent to
Intertek-
Genalysis Perth for chemical analysis.
DD samples: all sample preparation was
conducted at Intertek Perth. Each
entire sample is crushed to nominal
100% -3mm in a Boyd crusher then
pulverised to 85% -75µm in a LM5.The
entire submitted sample (=< ~3kg) is
pulverised to 85% -75µm in a LM5.
Approximately 100g pulp is collected
and sent to
Intertek-
Genalysis Perth for chemical analysis.
Quality control All sampling was carefully supervised.
procedures Ticket books were used with
adopted for all pre-numbered tickets placed in the
sub-sampling laboratory sample bag and double
stages to checked against the sample register.
maximise Subsequent to splitting
representivity ofan aluminium tag inscribed with hole
samples. id/sample interval was placed inside
the bulk 1-metre sample
bag.
Field QC procedures involve the use of
certified reference material assay
standards, blanks, duplicates,
replicates for company QC measures,
and laboratory standards, replicate
assaying and barren washes for
laboratory QC measures. The insertion
rate of each of these averaged better
than 1 in
20.
Measures taken All mass reduction (field and
to ensure that laboratory splitting) of samples were
the sampling is performed within
representative
of the in situ Gys Sampling Nomogram limits relevant
material to this style of mineralisation.
collected, Field duplicate splits of HA/AC
including for samples and quarter DD core were
instance undertaken nominally every 20th
results for sample to assess sampling
field errors.
duplicate/second A program of field replicate
-half splitting of selected (~10%)
sampling.
mineralised AC intervals was
completed at the conclusion of the
drill program. In addition, a number
of air core holes were drilled to
twin existing HA and DD holes, to
assess the
representivity of the AC drill
samples. The results of these
programs indicate there are no
significant sampling
errors.
Whether sample All mass reduction of aircore drill
sizes are samples undertaken during field
appropriate to sampling and laboratory sample
the grain size preparation were guided by standard
of the material sampling nomograms and fall within
being
sampled. Gys safety limits for the type of
mineralisation
sampled.
QualitThe nature, The assaying and laboratory procedures
y of quality and are considered to be appropriate for
assay appropriateness reporting graphite mineralisation,
data of the assaying according to industry best practice.
and and laboratory
labor procedures used
atory and whether the Each entire sample was pulverised to
tests technique is 85% -75µm. Approximately 100g pulp is
considered collected for analysis at
partial or Intertek-
total. Genalysis Perth.
A sample of 0.2g is removed from the
100-gram pulp, first digested in
HCl to remove carbon attributed to
carbonate, and is then heated to
450°C to remove any organic carbon.
An
Eltra CS-2000 induction furnace
infra-red CS analyser is then used to
determine the remaining carbon which
is reported as Total Graphitic Carbon
(TGC) as a
percentage.
For geophysical No non-laboratory devices were used
tools, for chemical
spectrometers, analysis.
handheld XRF
instruments,
etc., the
parameters used
in determining
the analysis
including
instrument make
and model,
reading times,
calibrations
factors applied
and their
derivation,
etc.
Nature of Field QC procedures involve the use of
quality control certified reference material assay
procedures standards, blanks, duplicates and
adopted (e.g. replicates for company QC measures,
standards, and laboratory standards, replicate
blanks, assaying and barren washes for
duplicate, laboratory QC measures. The insertion
external rate of each of these averaged better
laboratory than 1 in
checks) and 20.
whether
acceptable
levels of
accuracy (i.e.
lack of bias)
and precision
have been
established.
VerifiThe verification Significant mineralisation
cation of significant intersections were verified by
of intersections alternative company personnel. An
sampl by either independent resource consultant
ing & independent or (Competent Person, Mineral Resources)
assay alternative conducted a site visit during
ing company December 2016 during the
personnel.
aircore drilling program. All drilling
and sampling procedures were observed
by the CP during the site visit.
These procedures remained in use for
the 2017 drilling program.
The use of Several of the 2016 PQ diamond core
twinned holes were twinned by
holes.
aircore holes to assess sampling repres
entivity
.
Documentation of All data is initially collected on
primary data, paper logging sheets and codified to
data entry the Company's templates. This data
procedures, was hand entered to spreadsheets and
data validated by Company geologists.
verification, This data was then imported to a
data storage Microsoft Access Database then
(physical and validated automatically and
electronic) manually.
protocols.
Assay data is provided as .csv files
from the laboratory and loaded into
the project specific drill
hole database. Spot checks are made
against the laboratory
certificates.
Discuss any No adjustments have been made to assay
adjustment to data.
assay data.
LocatiAccuracy and Collar points were set out using the
on of quality of Companys R2 Rover DGPS (accuracy
data surveys used to 0.04m x/y), and upon completion of
point locate drill drilling all collars were picked-up
s holes (collar again using the same survey tool. The
and down-hole accuracy of R2 Rover unit is quoted
surveys), to be 0.04m x/y and 0.09m
trenches, mine z.
workings and
other locations Down-hole surveying was undertaken on
used in Mineral selected holes to determine drill
Resource
estimation. hole deviation. Surveys were carried
out using a Reflex
Ez-Trak multi-shot survey tool at
nominal 30m intervals down hole on
selected holes was used to show that
significant deviation does not occur
over the relatively short length of
the
aircore holes. As such drill hole devi
ation is not considered material
throughout the program.
Specification of WGS84 (GRS80) UTM Zone 36 South
the grid system
used.
Quality and The Companys DGPS survey tool has sub
adequacy of 0.1m accuracy in the X, Y and Z
topographic planes. This is considered
control. sufficiently accurate for the
purposes of topographic control. In
addition, the Company has installed
several independently surveyed
control pegs and undertakes QC
surveys on these points before every
survey program. Given the low
topographic relief of the area it is
believed that this represents high
quality
control.
Previous checking of Hand Auger holes
with the Shuttle Radar Topographic
Mission (SRTM) 1-arc second digital
elevation data has shown that the
Leica GPS System produces
consistently accurate
results.
Data Data spacing for Drill holes occur along east-west
spaci reporting of sections spaced at between 100-400m
ng & Exploration north-south between 8,434,400mN to
distr Results. 8,437,800mN. Spacing along drill
ibutio lines generally ranges between 15m
n and 40m. Between sections 8,436850
and 8,437,150 drill lines are spaced
at 50 m intervals with holes along
section lines at 20 m
spacing.
Whether the data The Companys independent resource
spacing and consultants completed a Mineral
distribution is Resource Estimate (MRE) for
sufficient to
establish the Malingunde in 2017 following the
degree of completion of the 2016 drilling
geological and program. The drill
grade
continuity hole sample data sourced in 2017 has
appropriate for allowed an update to the MRE (this
the Mineral document).
Resource and
Ore Reserve
estimation
procedure(s)
and
classifications
applied.
Whether sample No sample compositing has occurred.
compositing has
been
applied.
OrientWhether the No bias attributable to orientation of
ation orientation of sampling upgrading of results has
of sampling been
data achieves identified.
in unbiased
relat sampling of
ion possible
to structures and
geolo the extent to
gical which this is
struc known
ture considering the
deposit
type
If the No bias attributable to orientation of
relationship sampling upgrading of results has
between the been identified. Flake graphite
drilling mineralisation is conformable with
orientation and the main primary layering of the
the orientation gneissic and schistose host
of key
mineralised lithologies. Drill hole inclination of
structures is -60 degrees are generally near
considered to orthogonal to the interpreted
have introduced regional dip of the host units and
a sampling dominant
bias, this foliation.
should be
assessed and
reported if
material.
SampleThe measures Samples are securely stored at the
secur taken to ensure Companys compound in Lilongwe. Chain
ity sample of custody is maintained from time of
security sampling in the field until sample is
dispatched to the
laboratory.
AuditsThe results of The Competent Person (Mineral
or any audits or Resources) reviewed sampling
revie reviews of techniques and data during the
ws sampling December 2016 site visit. The field
techniques and crew were following company sampling
data procedures and the CP did not note
any issues of significance during the
inspection.
It is considered by the Company that
industry best practice methods have
been employed at all stages of the
exploration.
Section 2 Reporting of Exploration Results
Criter JORC Code Commentary
ia explanation
MineraType, reference The Company owns 100% of 4 Exclusive
l name/number, Prospecting Licences (EPLs) in
tenem location and Malawi. EPL0355 renewed in 2017 for
ent & ownership 2 years, EPL0372 renewed in 2018 for
land including 2 years and EPL0413 renewed in 2017
tenur agreements or for 2 years. EPL0492 was granted in
e material issues 2018 for an initial period of three
statu with third years
s parties such as (renewable).
joint ventures,
partnerships,
overriding
royalties,
native title
interests,
historical
Leseranfragen:
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Datum: 12.06.2018 - 10:53 Uhr
Sprache: Deutsch
News-ID 576810
Anzahl Zeichen: 110564
contact information:
Town:
Wien
Kategorie:
Business News
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"Sovereign Metals Limited: Resource Upgrade: Malingunde Flake Graphite Project
"
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