Advancing rare earth exploration in Australia

Richard Brescianini, Executive Director of Heavy Rare Earths Limited, details the company’s progress at its rare earth exploration projects in Western and Central Australia, including its flagship Cowalinya project.

Heavy Rare Earths Limited (ASX:HRE) is an Australian rare earth exploration and development company with a key clay-hosted rare earth exploration project in Western Australia. Although still in its early stages, the company is making significant progress towards turning its flagship project into a promising development for the production of rare earths.

To find out more, The Innovation Platform spoke to Executive Director Richard Brescianini.

Can you start by explaining the background of your company, how it was formed, and why you decided to focus on rare earth exploration?

Heavy Rare Earths was formed in early 2022 and listed on the Australian Exchange in August 2022. The company first acquired an option on a property in Western Australia near Esperance where it completed around 3,000m of air core drilling. This resulted in a small resource of 28 million tones at 625 parts per million (ppm) of total rare earth oxides (TREO).

Before this resource had been calculated, I was approached to join the company due to my extensive knowledge and experience in rare earth exploration. I was impressed by the company’s progress and discipline in capital management and agreed to become a director of the company in February 2022.

The company came to market with one main project – Cowalinya, near Esperance. I also brought a second project into the company – Duke, in the Northern Territory – which is in the early stages compared to Cowalinya.

What is the managerial background of your company and how does this experience apply to your current work?

We are currently a small company. When dealing in resource development, and particularly in the business of rare earths, you must be certain that you have a ‘real project’ with strong potential to be turned into a mine before you invest in expanding the business.

I am an executive director and the only current staff member. There are also two non-executive directors on the board, who consult as required.

The Chairman, John Byrne, has over 40 years of experience in capital markets and bringing mines into development. We are aligned in our view that Cowalinya is a good project but is still in its infancy. We do not want to overwork and overspend on the project before we can determine that it is a viable potential development. We must first ensure that we have a good metallurgical understanding of the potential ore that is sitting in the ground.

The other non-executive director, Ryan Skeen, is the CEO of an Australian-listed company called First Au. He is very bright and focused and is currently learning the craft in the resources game. I value his judgement and my discussions with him.

Between the three of us, we have a good blend of skills. I have also retained the vendor of the Cowalinya project and continue to use him as a consultant, alongside another consultant. In addition, experts from Strategic Metallurgy are undertaking our metallurgical test work.

Can you elaborate on the Cowalinya project?

The Cowalinya rare earth exploration project, located between Norseman and Esperance, is our main project. The area has various infrastructures in place to support development in the region, including a rail line running between Kalgoorlie and Esperance, which is used for the export of iron ore.

The project sits on Unallocated Crown land, which is a part of the Native Title Act. This process is fairly straightforward as it removes the need to negotiate access agreements or commercial arrangements with farmers, which can be more challenging.

The rare earth mineralisation at Cowalinya sits on saprolite weathered basement rocks that have been upgraded by weathering processes over long periods of time. These saprolite sequences are buried under a thin veneer of sand and cannot be seen at the surface, but ‘saprolite horizons’ can be reached by drilling just a few metres down. Drilling into these saprolites returned concentrations of rare earths that have been sourced from the basement rock, which are granites, granitic rocks, and high-grade metamorphic rocks. Here, we see concentrations of rare earths up to many thousands of ppm TREO.

In total, we have drilled around 550 vertical air core holes and 15,600m over two campaigns. Throughout this process, we outlined 28 million tonnes of resources in the first 109 holes. Whilst we have not yet outlined any more resources from the other 441 holes, we have identified a lot of mineralisation that will now form a resource estimation exercise.

The existing resource is in two distinct areas, known as Cowalinya North and Cowalinya South, over a total of 2km2. As I mentioned earlier, we have 250km2 under title, and we have drilled 2km2 of that to achieve 28 million tonnes of resources.

We have since drilled another 16km2, 13km2 of which is a new rare earth exploration area called the ‘Western Zone’. Across this zone, we found an average thickness of 11m of mineralised saprolite. The average width over the existing resource areas of Cowalinya North and South is 10m, so we have managed to increase the thickness of the mineralised horizon by 10%. We have seen higher grades as an average in the Western Zone compared to Cowalinya North and South. In our resource estimation process, which is just about to commence, we expect to see a material increase in the mineral resources for the project.

Do you have any other projects?

The Duke project in the Northern Territory is a very early stage rare earth exploration project. Here, we have two granted exploration licences and are looking for rare earths in hard rock, rather than in clays like at Cowalinya. Whilst the area has been explored previously for copper gold, gold and uranium, it has never been looked at for rare earths. We believe that there may be some ‘Browns Range’ style deposits here, which are hosted in a mineral called xenotime, which is enriched in heavy rare earths.

We have also applied for two more exploration projects in Western Australia, which are currently still at the application stage.

What will the rest of 2023 look like for the company? What do you hope to achieve this year and beyond?

Our recent ASX market announcement shows assay results from holes that we have drilled up to 15km away from our resource area. As you can see from the results, this is an outstanding find, and we are happy to convey the blue-sky potential of other rare earth exploration target areas on our 250km2. We want to demonstrate that, not only are we dealing with an area of known resources and expanded resources around it, but that there are other potential areas for future drill campaigns.

From there, the grid space drilling we have completed will enter a phase of resource estimation. This will be undertaken by a resource consultant over a two-to-three-month period. We hope to release an upgraded resource estimation for the project early in the new financial year. This will become the platform for the project in terms of articulating the potential size of the resources sitting on our land position. In addition, as part of that process, the resource consultant will calculate an exploration target.

Beyond this, we will continue with our metallurgical test work programme. Half of our programme and the most fundamental part of the project centres around building a resource base to demonstrate that there is enough resource in the ground for many years of development. The other half of the programme is to demonstrate that rare earths can be extracted from ore cheaply and easily and to optimise the viability of the project.

We must also demonstrate that we have a metallurgical process. The first step is to determine where in the mineralisation the rare earths are hosted. Currently, we have identified that, in the material for our mineralisation, over 85% of the rare earths are hosted in what we call the -25 micron fraction in very fine grained silt to clay-sized material. That is where most of the rare earths are and where we need access to for processing.

Once you have identified your material, you must then develop a metallurgical process to determine how to extract the rare earths from the fine material in your mineralisation. We are currently in the middle of our leach test work with Strategic Metallurgy. Our test work programmes are now focusing on the optimum conditions to apply the leach. Whilst we have some results internally as to how much we can leach out, we must now examine the best conditions in which to maintain the extraction of rare earths under commercial conditions rather than laboratory conditions.

Please note, this article will also appear in the fourteenth edition of our quarterly publication.

Contributor Details

Richard Brescianini

Executive Director
Heavy Rare Earths Limited
Phone: +61 3 8630 3321
Website: Visit Website

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