Empire
Metals Limited / LON: EEE / Sector: Natural Resources
7 November 2024
Empire Metals
Limited
("Empire" or "the Company")
Metallurgical Tests Confirm Weathered Zone Titanium
Mineralisation Highly Amenable to Heavy Mineral
Separation
Outstanding Drill Intercepts in Recent Diamond
Drilling Programme
Empire Metals Limited (LON:
EEE), the AIM-quoted resource exploration
and development company, is pleased to
announce the results of metallurgical gravity testwork carried out
on anatase-rich weathered cap samples from the Pitfield Project
('Pitfield'), located in
Western Australia. The recent discovery of high-purity anatase
mineralisation located within the near-surface, strongly weathered
"saprolite" cap covering the giant, 40km long, titanium-rich
mineral system at Pitfield has shifted Empire's immediate focus to
defining a process route for weathered zone titanium
mineralisation.
The geochemical analysis results
from the recently completed diamond core drilling programme have
been received. These results confirm the successful mapping of
extensive, high-grade weathered zones from very near surface to
depths of around 60 metres, nearly double that previously
encountered at the Cosgrove and Thomas prospects.
Highlights
· A heavy mineral concentrate was achieved from the preliminary gravity tabling tests on the anatase-rich
weathered zone samples, with high a recovery of titanium and iron
(up to 80% and 92% respectively) and importantly a high rejection
of aluminium and silica minerals.
· Preliminary froth flotation testwork on the weathered samples
has also been positive. Sighter rougher tests produced a
concentrate containing 78% of the TiO2 bearing
minerals with a rougher concentrate grade of
8.8% TiO2.
· The combination of gravity and flotation mineral separation
techniques shows significant promise as a processing route for
firstly producing a heavy mineral concentrate, and then for further
mineral separation stages to separate and recover the
TiO2 bearing minerals into a high-grade, high-purity
concentrate.
· The latest diamond core drilling has provided
substantial quantities of high-grade, high-purity anatase-rich
samples to accelerate the mineral processing test work and has
successfully mapped out the thickness, grade, shape and extent of
the anatase-rich weathered cap.
· The Company has expanded its mineralogical and metallurgical
testwork programme, with considerable activity planned in November
- December 2024 and beyond, and involves collaboration with both
international and locally based expert consultants and utilises
government and commercially owned metallurgical laboratory
facilities in Australia.
· The development of a processing flowsheet will advance through
H1 2025, with the Company now considering a lower capital and
operating cost option for a continuous pilot plant facility, thanks
to the discovery of the high-grade, high-purity anatase
mineralisation in the soft, friable near-surface weathered
cap.
· Discussions initiated with government authorities in relation
to research and development rebates, development grants and the
Exploration Incentive Scheme funding, with opportunities for
further funding via Export Finance Australia, which manages the
Australian Government's $4 billion "Critical Minerals Facility",
providing funding for projects planning to produce critical
minerals listed in Australia's Critical Minerals Strategy, such as
titanium.
Shaun Bunn, Managing Director, said:
"I am extremely
pleased to report that we have successfully produced a heavy
mineral concentrate from the preliminary gravity tabling tests on
the anatase-rich weathered zone samples. During the testwork there was a clear visual
difference between products coming off the table, indicating
separation of heavy, dark coloured minerals from the lighter
coloured gangue minerals. This has been confirmed by the
assay results indicating high recovery of titanium and iron, and
high rejection of aluminium and silica. The next phase of the
testwork programme, using samples from the recent drilling
programme, will focus on unit processes to separate the iron oxide
minerals from the titanium oxide and titanium-iron-oxide minerals
to produce a high-grade TiO2 mineral
concentrate.
"We have also now
received the geochemical analysis results for the recently
completed diamond core drilling programme which have identified
extensive, high-grade TiO2 weathered zones from very
near surface to depths of around 60 metres, nearly double that
previously encountered at the Cosgrove and Thomas prospects, and
also confirming the extremely soft and friable nature of the bedded
sandstones in this weathered zone."
Metallurgical Test
Results
Quartered drill core samples collected from earlier
drilling (February-March 2024) was used to create a small composite
sample from the weathered zone. The composite sample was used for
diagnostic gravity testwork to progress the metallurgical
understanding of the weathered zone, whilst awaiting larger whole
of core samples from the September - October 2024 diamond drill
programme.
Mineralogical analysis was completed using TIMA SEM
based measurement, to confirm the extent of weathering and the
detailed mineralogical breakdown of both the titanium and gangue
minerals. This analysis confirmed that the titanium is contained
within anatase, a high-purity titanium dioxide mineral, a range of
high-grade titano-iron-oxide minerals (collectively referred to as
leucoxenes) and ilmenite. Trace amounts of titanite were also
observed in some of the weathered samples.
A preliminary gravity table test was completed on the
weathered sample. In this test the sample was crushed and ground to
100 percent passing 150µm. The sample was then screened to remove
fines prior to running the wet gravity table test. The head grade
of the screened sample was 6.0% TiO2.
The performance of the gravity tabling of the
weathered sample was extremely positive with a heavy mineral
concentrate ("HMC") being recovered that contained 62 to 80% of the
TiO2 bearing minerals and 88.3 to 92% of the Fe-oxide
minerals, mainly hematite (refer Table 1). The concentrate
streams were largely free of the lighter, acid consuming gangue
silicates. The mass recovery into the first three concentrate
streams was 40%, produced a heavy mineral concentrate containing
62% of the TiO2 at a grade of 9.3%TiO2. An
additional concentrate stream (#4) was produced which took overall
TiO2 recovery to 80.1% albeit at a lower overall
concentrate grade, due to locked mineral particles. The HMC
produced will require further mineral processing to separate and
recover the TiO2 bearing minerals into a high-grade,
high-purity concentrate suitable for leaching. The remaining
hematite rich concentrate will be tested to see if it can be
recovered as an iron by-product.
Table 1. Gravity Table Results
Mineral Group within Heavy Mineral Concentrate
('HMC')
|
Cons 1-3
|
Cons 1-4
|
% Recovery
|
% by mass in HMC
|
% Recovery
|
% by mass in HMC
|
HMC Mass
|
40
|
|
67
|
|
Titanium
Dioxide
|
43.3
|
2.2
|
68
|
2.1
|
Ilmenite
group
|
70
|
12.4
|
87
|
9.2
|
Titanite
|
84
|
0.9
|
94
|
0.6
|
Fe Oxides
|
88.3
|
45
|
92
|
29
|
Gangue Silicates/
other minerals
|
19
|
|
54
|
|
Total
TiO2
|
62
|
9.3
|
80
|
7.2
|
Clockwise from the
left: Figure 1. Gravity table set up, Figure 2. Close up of table
in operation, showing concentration of darker coloured minerals in
the HMC zone, and Figure 3. Final table test products 1-5 (L-R)
with cons 1-3 making up the HMC, cons 4 for recycle and product 5
tailings.
Froth flotation testwork on the weathered sample has
also shown promise. Froth flotation is selective separation process
to separate valuable minerals (in this case anatase and/or
titanite) from unwanted gangue (aluminium and silica minerals)
using fine air bubbles in a series of flotation cells, of varying
designs. Sighter rougher tests (the first concentration stage in
the flotation process) trialling a range of reagent chemistries
from industry and literature gave a concentrate containing 60% of
the feed mass, with a titanium recovery of 78% to a rougher
concentrate grade of 8.8% TiO2. Mineralogical analysis
of the flotation concentrate is pending and once received further
mineral separation testwork will be conducted to separate and
recover the TiO2 bearing minerals into a high-grade,
high-purity concentrate.
Figures 4 &
5. Flotation reagent testing on weathered zone
samples.
Further analysis is underway on the products from
these initial tests, to understand the mineral deportment and
influence of particle size.
These results demonstrate that mineral separation can
be achieved on the Pitfield drill core samples. Further
optimisation is needed for this stage, and additional stages in
order to increase concentrate grade. These results begin to pave
the path for flowsheet development on Pitfield, helping to narrow
the options being assessed. The new drill core samples will be an
important feedstock for further mineral concentration and titanium
extraction.
The full PQ size (101.5mm diameter) drill core from
the recent drilling programme has been received at the
metallurgical testwork laboratory in Perth. Samples for testwork
have been selected by the geology and metallurgical teams. A
multi-stage testwork programme is planned to step through the
flowsheet options, building on the results of the recent testwork
programme on preliminary samples. Work will include ore
characterisation, comminution steps suitable for the weathered
mineralisation, further development of the gravity and flotation
conditions, iron removal from gravity concentrates, and titanium
recovery from the slimes fraction.
Gravity testwork will continue on mineralised samples
from both the weathered cap zone and the underlying unweathered
bedrock throughout November and December, in order to evaluate the
effect of grind size on particle liberation and to produce mineral
concentrate samples for preliminary hydrometallurgical testing.
These tests will involve additional wet gravity tabling work as
well as initial testing of a Multi Gravity Separator ('MGS') which
is an enhanced gravity separation device with capability to treat
finer particle sizes than wet gravity tables or spirals.
Other mineral separation processes being assessed
include magnetic separation and froth flotation.
Given the soft, friable nature of the weathered zone
a comminution testwork programme will commence in November 2024 on
the new diamond drill core samples to investigate the potential for
low intensity crushing/grinding techniques such as log washers or
scrubbers.
Diamond Core Drill
Results
The Company recently announced (24 October 2024) the
completion of Diamond Core drilling at the Thomas and Cosgrove
prospects. The focus of the drill campaign was on providing
additional drill core samples for metallurgical test work as well
as a better geological understanding of the weathered cap zone,
including thickness, grade and shape.
This diamond drilling programme at Pitfield drilled
ten holes, five at the Cosgrove prospect and five at Thomas
prospect. Of these ten holes, four will remain uncut and the whole
core sample will be dedicated to metallurgical test work. The six
remaining holes have had a quarter of the core removed for
geochemical assaying and half the core will be used for
metallurgical testwork, the remainder being kept in storage.
The geochemical data returned from this drill
programme has confirmed previous results which highlights
high-grade TiO2 in the near surface environment at both
the Thomas and Cosgrove prospects (Table 2). At the Cosgrove
prospect drillhole DD24COS004 in particular returned a
significantly elevated intercept of 4.6m @ 12.2% TiO2 from 14.85m including an interval of 17.97%
TiO2.
Table 2: Complete
intercepts from the whole hole including fresh material
Hole ID
|
Depth From
(m)
|
Depth To
(m)
|
EOH (m)
|
Interval
(m)
|
Grade TiO2
(%)
|
DD24TOM006
|
0
|
72.6
|
72.6
|
72.6
|
5.48
|
DD24TOM007
|
11.5
|
54.3
|
65.8
|
54.3
|
5.66
|
DD24TOM008
|
0
|
72.6
|
72.6
|
72.6
|
5.70
|
DD24COS004
|
0
|
78.7
|
78.7
|
78.7
|
5.55
|
DD24COS005
|
0
|
48.7
|
48.7
|
48.7
|
5.99
|
DD24COS006
|
0
|
48.4
|
48.4
|
48.4
|
6.14
|
The geochemical data confirms the previous modelling
carried out that predicted the depth of the weathered profile at
both prospects. The geochemical results show that the Thomas
project has deeper weathering than Cosgrove in general, with the
depth of weathering decreasing from south to north at Cosgrove and
decreasing west to east at Thomas (Table 3). The grade and
thickness of previous drilling has been confirmed by the data from
this drilling programme and provides more confidence in the
exploration target modelling previously done.
Table 3: Weathered
interval grade and thickness based on Ca values
Hole ID
|
Depth From
(m)
|
Depth To
(m)
|
EOH (m)
|
Weathered interval
(m)
|
Grade TiO2
(%)
|
DD24TOM006
|
0
|
46.5
|
72.6
|
46.5
|
5.94
|
DD24TOM007
|
11.5
|
51
|
65.8
|
39.5
|
5.82
|
DD24TOM008
|
0
|
58.5
|
72.6
|
58.5
|
5.89
|
DD24COS004
|
0
|
63
|
78.7
|
63
|
6.13
|
DD24COS005
|
0
|
30.5
|
48.7
|
30.5
|
5.35
|
DD24COS006
|
0
|
30
|
48.4
|
30
|
6.67
|
The geochemical data returned for the drill holes
associated with the geological logging data and core photos can now
be used to more accurately determine the depth of the weathering
profile. The downhole increase in calcium, magnesium and to a
lesser degree sodium can be used as markers for the depth of
weathering, as all of these elements are strongly depleted in the
weathering zone. This information will enable better modelling of
the geochemical data from previous RC drilling campaigns to provide
a more accurate interpretation of the weathered zone at both the
Thomas and Cosgrove prospects. The increased certainty about the
depth of weathering will also feed into decisions regarding future
drilling and where to drill to obtain the best results for any
future mineral resource estimate.
Future Work -
Pitfield Project Development Plan
The Pitfield Project is a unique giant-scale,
high-grade, soft-rock titanium deposit, comprising a suite of
non-refractory titanium-bearing minerals that the Company considers
hold the potential to process into a high value feedstock for the
pigment and/or titanium metal markets. Empire's vision remains to
develop the project as a fully integrated, mining, processing and
refining operation. The recent discovery of high purity anatase
within the weathered cap zone takes the Company one step closer to
this goal.
The Company has rapidly moved from an early
exploration phase into project development, largely thanks to the
very large yet simple nature of this giant titanium-rich mineral
system. Two separate metallurgical bulk samples, representing the
titanite-rich fresh bedrock and the anatase-rich weathered cap have
already been generated from drill core. These samples have provided
source samples for the mineralogical and metallurgical
characterisation work completed to date, specifically investigating
a range of known and emerging beneficiation and hydrometallurgical
processing steps to determine the process flowsheet.
The Pitfield Project Development Plan, originally
announced on the 27 March 2024, set out several important
milestones, many of which have now been achieved, including:
·
Mineralogical characterisation
studies of titanium mineralisation and related host alteration
mineral assemblages have been completed, which will further inform
both on-going metallurgical studies and the mineral resource
drilling, targeting high-grade, anatase-rich zones;
·
Metallurgical characterisation
studies are well advanced on the titanite-rich unweathered bedrock
mineralisation to determine ore characteristics, the beneficiation
steps required to separate titanium bearing minerals from gangue
minerals, and the leachability of the primary titanium
minerals;
·
A maiden JORC-compliant
Exploration Target has been defined consisting of two, distinct
high-grade, near surface bedded sandstone zones, referred to as the
Cosgrove and Thomas mineral prospects;
·
Government funding initiatives
underway, with the establishment of co-funding agreements with
Curtin University and CSIRO, Australia's national science
agency;
·
Commencement of environmental
impact and baseline studies, and continuation of stakeholder and
community engagement activities.
Metallurgical and
Mineralogical Studies
The ongoing metallurgical and mineralogical testwork
programme continues to focus on four key study areas, running in
parallel and all aimed towards expediting the design of a flowsheet
and establishing the operating conditions for a continuous piloting
facility.
The key aspects of the programme are:
1. Ore
Characterisation - Comminution
Developing a fundamental understanding of the
mineralisation across the project. This includes geochemistry,
mineralogy, grain size, breakage properties and hardness.
Standard comminution tests have already been
undertaken on mineralised drill core samples collected from the
unweathered bedrock as well as the overlying weathered cap zone to
provide information on rock competency and energy input for
breakage requirements. Weathered zone material was confirmed to be
very soft whereas the unweathered bedrock, whilst more competent,
is expected to fracture easily due to the bedding layers within the
sandstone sediments. Planning is underway for a full range of
comminution tests on both the weathered and fresh rocks, pending
receipt of full diamond 'PQ' drill core.
2.
Mineral Concentration
Testing of physical and chemical unit processes that
can separate out gangue minerals from titanium bearing minerals.
The key mineral concentration techniques currently under
investigation include:
· Gravity
separation testwork: initial gravity tabling tests focussed on
producing a low-grade mineral waste stream and a titanium-rich
mineral concentrate for further downstream processing;
· Magnetic
separation testwork: focused on separating weakly magnetic
minerals, like ilmenite, from non-magnetic minerals such as quartz
or hematite;
· Froth
Flotation testwork: focused on separating the finer gangue minerals
from the titanium bearing minerals utilising a range of physical
conditions and flotation chemicals.
3.
Hydrometallurgy
Bench-scale testwork to determine the leach response
of both the titanium minerals and the associated gangue minerals,
initially focused on bringing the titanium into solution, and then
looking to optimise the leach solution chemistry and define the
process steps for product finishing. The testwork is assessing acid
types (HCl and H2SO4) and their consumption,
options for reagent recycling, impurity management and options for
producing a final high-purity titanium product.
4.
Final product assessment
A high-grade, high-purity titanium product suitable
as feedstock for chloride pigment production or conversion into
titanium metal sponge has been identified as the most desirable
final product for the project. The possible process chemistries in
the leaching step provide a good synergy with this type of final
product. The potential to produce a range of different products,
depending on market demand, will be investigated in the testwork
programme. Additionally, any opportunity to produce a viable
by-product and to reduce waste streams is being explored.
Pilot Plant -
Process Flowsheet Design
The final output of the process development programme
will be a detailed flowsheet and inputs for the design of a
continuous pilot plant, and most importantly the confirmation of
successful extraction of titanium within an economic process that
can produce a high-value product. The pilot plant operation will
provide data for full-scale design, allow optimisation of the
process flowsheet in continuous operation mode, and provide key
operating parameters for economic assessment of the mining and
processing steps.
One of the key differences between the processing
options being considered for Pitfield and those commonly found in
the ilmenite industry is that a low temperature acid leach process
is likely all that is needed to extract the titanium and produce a
high-quality product. No energy-intensive smelting is required and
a higher value product can be produced on-site. Furthermore, thanks
to the discovery of a high-grade, high purity anatase-rich zone in
the soft, friable near-surface weathered cap there is significant
potential to establish a straightforward mineral separation
flowsheet. This will simplify the pilot plant design and help
reduce construction and operating costs of the pilot plant.
Government
Funding
The Company has initiated discussions with relevant
government authorities in relation to research and development
rebates, development grants and Exploration Incentive Scheme
funding. The Australian Government is actively supporting
investment in critical minerals projects as part of its Critical
Minerals Strategy. Export Finance Australia ('EFA') manages the Australian
Government's $4 billion Critical Minerals Facility and provides
funding for projects producing or planning to produce critical
minerals listed in Australia's Critical Minerals Strategy, such as
titanium. This includes activities undertaken post-exploration and
before final investment decision.
This is highlighted by the Australian Federal
Government committing $1.25 billion in funding via a low-cost,
non-recourse loan to support the Iluka Resources Ltd Eneabba
refinery in Western Australia (located 30km southwest of the
Pitfield Project) through EFA from its Critical Minerals Facility.
The Government also recently provided $400 million in new loans to
Australian company Alpha HPA Ltd to deliver Australia's first
high-purity alumina processing facility in Queensland. Alpha will
use Australian owned IP and technology to process high purity
alumina - a critical mineral used in LED lighting, semiconductors,
and lithium-ion batteries and other high-tech applications. These
loans were also provided by EFA, through the Government's $4
billion Critical Minerals Facility, as well as through the Northern
Australia Infrastructure Facility.
The Pitfield
Titanium Project
Located within the Mid-West region of Western
Australia, near the northern wheatbelt town of Three Springs, the
Pitfield titanium project lies 313km north of Perth and 156km
southeast of Geraldton, the Mid West region's capital and major
port. Western Australia is ranked as one of the top mining
jurisdictions in the world according to the Fraser Institute's
Investment Attractiveness Index published in 2023, and has
mining-friendly policies, stable government, transparency, and
advanced technology expertise. Pitfield has existing connections to
port (both road & rail), HV power substations, and is nearby to
natural gas pipelines as well as a green energy hydrogen fuel hub,
which is under planning and development (refer Figure 6).
Figure 6. Pitfield Project Location showing the
Mid-West Region
Infrastructure and Services
Competent Person
Statement
The technical information in this report that relates
to the Pitfield Project has been compiled by Mr Andrew Faragher, an
employee of Eclipse Exploration Pty Ltd, a wholly owned subsidiary
of Empire. Mr Faragher is a Member of the Australian Institute of
Mining and Metallurgy. Mr Faragher 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'. Mr Faragher consents to the inclusion
in this release of the matters based on his information in the form
and context in which it appears.
Market
Abuse Regulation (MAR) Disclosure
Certain
information contained in this announcement would have been deemed
inside information for the purposes of Article 7 of Regulation (EU)
No 596/2014, as incorporated into UK law by the European Union
(Withdrawal) Act 2018, until the release of this
announcement.
**ENDS**
For further information please visit www.empiremetals.co.uk or
contact:
Empire Metals
Ltd
Shaun Bunn / Greg Kuenzel / Arabella Burwell
|
Tel: 020 4583 1440
|
S. P. Angel
Corporate Finance LLP (Nomad & Broker)
Ewan Leggat / Adam Cowl
|
Tel: 020 3470 0470
|
Shard Capital
Partners LLP (Joint Broker)
Damon Heath
|
Tel: 020 7186 9950
|
St Brides Partners Ltd (Financial
PR)
Susie Geliher / Charlotte
Page
|
Tel: 020 7236 1177
|
About Empire Metals
Limited
Empire Metals is an AIM-listed
exploration and resource development company (LON: EEE) with a
primary focus on developing Pitfield, an emerging giant titanium
project in Western Australia.
Exploration activity at Pitfield has
confirmed the discovery of a new giant mineralised system extending
over 40km by 8km by 5km deep. Drilling campaigns have confirmed
high-grade TiO₂ mineralised zones across thick bedded intervals to
a vertical depth of ~350m, confirming Pitfield as a world class,
district-scale titanium mineral system.
Empire is now accelerating the
economic development of Pitfield, with the objective of becoming a
leading producer of high value titanium dioxide
products.
The Company also has two further
exploration projects in Australia; the Eclipse Project and the
Walton Project in Western Australia, in addition to three precious
metals projects located in a historically high-grade gold producing
region of Austria.