Significant Progress Achieved on Process Flowsheet

Empire Metals Limited / LON: EEE / Sector: Natural Resources

13 February 2025

Empire Metals Limited

("Empire" or "the Company")

Significant Progress Achieved on Process Flowsheet

Focus now on Product Development

Empire Metals Limited (LON: EEE), the AIM-listed resource exploration and development company, is pleased to announce the results from its recent mineral separation and hydrometallurgical testwork programme, carried out on core samples taken from the weathered cap that extends across the Pitfield Project ('Pitfield'), located in Western Australia.

Highlights

·    Development of the processing flowsheet continues at a rapid pace with several of the initial process stages now tested and proven to be effective for recovering anatase and rutile, the most abundant titanium minerals encountered in the mineralised weathered cap.

·  The test work results achieved to date indicate that a combination of gravity and flotation techniques offers a straightforward processing method to produce a clean, anatase-rich concentrate, which can be further upgraded via acid leaching to yield high-grade, high-purity TiO₂.

·    The weathered cap, extending from surface to over 50m deep, is highly friable and amenable to low-cost scrubbing and desliming to remove fines before applying simple gravity recovery on the coarser fraction to produce a titanium mineral concentrate.

·    Titanium dioxide mineral separation and concentration was achieved on the finer fraction of the deslimed weathered samples, utilising froth flotation. Titanium was subsequently extracted from the flotation concentrates using an industry standard acid-bake water leach process with a 91% titanium extraction rate.

·    Further optimisation of the flotation conditions is planned, aiming to increase recovery.  Cleaner stage flotation will also be tested, in order to increase concentrate grades.

Shaun Bunn, Managing Director, said: "I am extremely pleased to provide this update on the success of the ongoing metallurgical testwork and flowsheet development, which continues to gather great momentum. The successful application of froth flotation to recover high-grade titanium dioxide minerals from the fines fraction of the weathered ore is an important step in designing an efficient and robust process flowsheet. Importantly, the titanium dioxide minerals contained within the flotation concentrates responded well to the subsequent leaching stage, with titanium recoveries peaking at 91%.

"Looking ahead, the metallurgical testwork will now focus on testing various titanium product development options and will assess the purification and refining stages to determine the steps required to achieve a high-purity, high value TiO₂ product."

Metallurgical Testwork and Flowsheet Development

Metallurgical research and testing have been focussed on conventional processing stages, such as gravity, flotation and acid digestion, to achieve a cost-effective process flowsheet aimed towards producing a high-value commercial product.

With the discovery of high-grade titanium dioxide minerals within the weathered cap that extends across the entirety of this giant titanium mineral system, the development team's focus shifted over the past several months to testing the metallurgical and mineralogical characteristics of the weathered ore samples. The ten diamond core drillholes from the campaign carried out in September-October 2024 (announced 24 October 2024) provided excellent core recovery from the weathered zone and provided representative metallurgical samples which have accelerated the development testwork.

Notable testwork achievements on the weathered ore samples reported to date include:

•             Slurry separation at 38 microns provides a suitable feed for gravity and flotation feed;

•             Gravity separation recovered 60-80% of Ti-bearing minerals into a heavy mineral concentrate;

•             Acid leach tests on gravity concentrates achieved 95% dissolution of anatase; and

•       Separate flotation test work on whole of ore samples achieved 78% TiO₂ recovery into a rougher mineral concentrate.

Recent XRD analysis has confirmed that the mineral assemblage within the high-grade weathered zone is primarily titanium dioxide minerals: anatase and rutile. Mineralogical (microprobe) analysis has also identified that the anatase and rutile are of high purity, being very low in deleterious contaminants.

The development of a process flowsheet continues to advance rapidly and the testwork results achieved to date continue to build confidence that a combination of gravity and flotation techniques offers a straightforward processing method to produce a clean, anatase-rich concentrate, which can be further upgraded via acid leaching to yield high-grade, high-purity TiO₂ (refer Figure 1.)

Figure 1.  Conceptual Flowsheet for the Pitfield Titanium Project.

Key features and benefits of the current flowsheet include:

·    Highly friable, weathered ores allow for simple, low-energy scrubbing and desliming circuit

·    Conventional mineral separation processes (gravity/flotation) to concentrate the Ti-bearing minerals, rejecting the gangue silicates

·    Acid leaching and precipitation to produce a high-quality TiO₂ product (>80% TiO₂ )

·    Further refining to achieve final product (>95% TiO₂) suitable for:

o  Chloride pigment market and the manufacture of paints and coatings, plastics and paper; and

o  Production of titanium metal (sponge)

Recent Metallurgical Testwork Results

Previously reported test work results were related to the treatment of either whole of ore samples or the coarse fraction after a deslimes stage. Testwork has now been undertaken on the fine fraction from the deslimes stage.

Drill core samples of weathered ore were crushed and then split into coarse particle (+38 micron) and fine particle (-38 micron) fractions using a fine wet screening process. The coarse fraction gravity and leach testwork has previously been reported (announced 7 November 2024 and 9 December 2024 respectively). Metallurgical testing of the fine fraction from the screening process has now commenced at ALS Metallurgy in Perth, with the initial work focused on titanium mineral separation and concentration, followed by acid leach extraction.  

Mineral separation was assessed using froth flotation. A flotation "rougher" concentrate was then taken forward for an acid bake-water leach test to extract the titanium into solution.

Fines Flotation Testwork

A range of flotation conditions have been tested based on literature and reagent vendor recommendations. Focus so far has been on conditions that have been used in the kaolin industry for many years. In order to produce high quality kaolin, otherwise known as "China Clay", it is quite common to remove any anatase present as this may discolour the kaolin products. Flotation of fine anatase has thus been common industry practice for many decades and through the application of optimised reagent conditions it can be selectively recovered. The initial diagnostic work tested a range of reagent conditions, achieving a recovery high of 61% TiO₂ (Figure 2).

Further optimisation of the flotation conditions is planned, aiming to increase recovery. Cleaner stage flotation will also be tested, in order to increase concentrate grades.

Mineral analysis using XRD has shown that anatase is being selectively recovered to the flotation concentrate during the froth flotation tests, with gangue minerals such as quartz, kaolinite and smectite clays reporting to the flotation tailing stream.

Additional mineral analysis using TIMA and SEM techniques are being undertaken on the flotation concentrates and tailings stream. Further insight on mineral recovery, liberation and association will be provided by the additional mineralogy work.

Figure 2. Testing of the weathered ore fines samples: photo on left shows flotation concentrate being recovered and photo on right shows the water leach stage post acid baking of the flotation concentrate.

Acid Leach Testwork

The flotation "rougher" concentrate produced from the testwork was used to carry out diagnostic acid leach testwork.  As in the case of the gravity heavy mineral concentrate preliminary sighter leach testwork was carried out using an industry standard acid bake-water leach process, conditions being based on available literature for the leaching of anatase ores (Figure 2). A second leach test was carried out with a pre-leach step ahead of the standard acid bake water leach process to see the effect of removing acid consuming gangue prior to the acid bake step. The test results were extremely encouraging, with 82% titanium extraction being achieved for the initial acid-bake water wash test, increasing to 91% titanium extraction with the addition of a pre-leach step (refer Table 1).

Table 1. Sighter Acid-Bake Water Leach Recoveries

Further Work Planned in 2025

A sequence of additional resource-focused drilling, scaled-up metallurgical testwork programmes and mining and engineering studies is planned that will form the building blocks that are required to reach commercialisation. In particular, the Company intends to complete:

·    bulk sampling and metallurgical testwork to deliver flowsheet design and high-quality product specifications

·    engage with industry players to test product suitability for chloride pigment and Ti sponge metal feedstock

·    in-fill drill and prepare a Maiden Resource Estimate

·    mining option studies proving low-cost potential

·    pilot plant design and commissioning, aimed at optimising the process flowsheet and product specifications, as well as defining unit economics.

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 4).

Figure 4. Pitfield Project Location showing the Mid-West Region Infrastructure and Services

Competent Person Statement

The scientific and technical information in this report that relates to process metallurgy is based on information reviewed by Ms. Narelle Marriott, an employee of Empire Metals Australia Pty Ltd, a wholly owned subsidiary of Empire. Ms. Marriott is a member of the AusIMM and has sufficient experience 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 JORC Code 2012. Ms. Marriott consents to the inclusion in this announcement of the matters based on their information in the form and context in which it appears.

The technical information in this report that relates to the geology and exploration of the Pitfield Project has been compiled by Mr Andrew Faragher, an employee of Empire Metals Australia Pty Ltd, a wholly owned subsidiary of Empire. Mr. Faragher is a member of the AusIMM and 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 JORC Code 2012. 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:

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.

The high-grade titanium discovery at Pitfield is of unprecedented scale, with airborne surveys identifying a massive, coincident gravity and magnetics anomaly extending over 40km by 8km by 5km deep. Drill results have indicated excellent continuity in grades and consistency of the mineralised beds and confirm that the sandstone beds hold the higher-grade titanium dioxide (TiO₂) values within the interbedded succession of sandstones, siltstones and conglomerates. The Company is focused on two key prospects (Cosgrove and Thomas), which have been identified as having thick, high-grade, near-surface, bedded TiO₂ mineralisation, each being over 7km in strike length.

An Exploration Target* for Pitfield was declared in 2024, covering the Thomas and Cosgrove mineral prospects, and was estimated to contain between 26.4 to 32.2 billion tonnes with a grade range of 4.5 to 5.5% TiO₂.  Included within the total Exploration Target* is a subset that covers the weathered sandstone zone, which extends from surface to an average vertical depth of 30m to 40m and is estimated to contain between 4.0 to 4.9 billion tonnes with a grade range of 4.8 to 5.9% TiO₂.

The Exploration Target* covers an area less than 20% of the overall mineral system at Pitfield which demonstrates the potential for significant further upside.

Empire is now accelerating the economic development of Pitfield, with a vision to produce a high-value titanium metal or pigment quality product at Pitfield, to realise the full value potential of this exceptional deposit.

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.

*The potential quantity and grade of the Exploration Target is conceptual in nature. There has been insufficient exploration to estimate a Mineral Resource and it is uncertain if further exploration will result in the estimation of a Mineral Resource.