Empire Metals Limited Pitfield: Positive Drilling & Metallurgical Update

RNS Number : 2692L

Empire Metals Limited

07 November 2024

 

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: [phone]
S. P. Angel Corporate Finance LLP (Nomad & Broker) Ewan Leggat / Adam Cowl	Tel: [phone]
Shard Capital Partners LLP (Joint Broker) Damon Heath	Tel: [phone]
St Brides Partners Ltd (Financial PR)                                          Susie Geliher / Charlotte Page	Tel: [phone]

 

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.

 

 

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