The Koppamurra project is an ionic clay hosted rare earth mineral deposit located in the Australian states of South Australia and Victoria.
Australian Rare Earths Limited (AR3), formerly known as Tawel Exploration, owns 100% stake in the project.
The deposit hosts all four key rare earth elements- praseodymium, neodymium, terbium and dysprosium.
Two drilling campaigns at Koppamurra were conducted in 2021 and 2022, following which, the company decided to advance to the next stage which will involve commissioning a range of environmental studies to develop baseline information necessary for a Mining Lease (ML) application.
In March 2023, AR3 achieved a successful pilot-scale production of a Mixed Rare Earth Carbonate (MREC) from around 800kg of Koppamurra bulk sample. The company plans to continue to define the resource at the property during 2023.
The project is expected to achieve first production in 2025/26.
Location, Geology and Mineralisation
Koppamurra Project consists of multiple granted Exploration Licences (EL) including EL6509, EL6613, EL6690 and EL6691 in South Australia, and EL7254 in Victoria.
The licences encompass an area of more than 4,000km2.
The rare earth element (REE) mineralisation at the project occurs in clayey sediments interpreted to have been deposited onto a limestone base (Gambier Limestone) and accumulated in an interdunal, lagoonal or estuarine environment.
As of April 2023, a programme investigating the source of the REE at the project is ongoing. However, preliminary results of this study ruled out the alkali volcanics in south-eastern Australia as a potential source.
The dominant clay minerals in the property are smectite and kaolin.
The Koppamurra project is identified as a potential key future source of Neodymium (Nd), Praseodymium (Pr), Terbium (Tb) and Dysprosium (Dy). These four rare earths are expected to constitute more than 92% of the revenue of the project’s output.
Koppamurra Mineral Resource Estimate
According to AR3, Koppamurra has immense growth potential with less than 5% defined resource of the total exploration tenure.
Following the two drilling programmes of February 2022 and April 2022, the project’s JORC Resource was 81.4 million tonnes (Mt) at 785ppm total rare earth oxide (TREO). This includes the delivery of the first JORC Indicated Resource of 45Mt at 835ppm TREO.
In April 2023, AR3 announced a 25% increase in Koppamurra mineral resource.
The JORC Mineral Resource estimate for the project now stands at 101Mt at 818ppm TREO, while Indicated Resource category increased by 40% to 63Mt at 839ppm TREO.
The mineral resource estimate contains 1Mt of Measured Resource category with the grade at 894ppm TREO.
The update is based on results of the 13,400m drilling campaign conducted in the December quarter of 2022.
Drilling campaign and Mining
The drilling programme completed between September and December 2022 added 13,400m (1,239 holes) to the existing 26,185m (2,727 holes) drilled for the previous mineral resource estimate that was announced in July 2022.
The 2022 drilling programmes generated more than 8,000 samples across 1,239 drill holes.
A new Exploration and Resource Definition drilling program commenced in January 2023. This is scheduled to continue until May 2023, targeting a total of 10,000m to expand the existing mineral resource of Koppamurra project.
It will also assess regional extensions of the wider prospect area.
No specific mining methods were considered into the modelling process. However, a form of dry mining will be undertaken.
AR3 expects the production process to be simpler which may separate all the rare earths contained in other rare earth minerals.
Key Contracts and Agreements
IHC Robbins was engaged to complete the Mineral Resource Estimate for the Koppamurra Project.
McLeod Drilling conducted air core drilling at the project site using a Toyota Land air core rig and support vehicle.
A review of the Australian Rare Earths Azure Data Studio database was undertaken by engineering and project management company Wallbridge Gilbert Aztec (WGA).
During the drilling, sampling and geological logging process and throughout the sample collection and dispatch process, Aussie Geologic conducted internal reviews.
In October 2022, a local earthworks company Henschke Industries was contracted by AR3 for trial mining activities at the rare earth project.
Mineralogical analysis and metallurgical testing were conducted between December 2021 and March 2022 in conjunction with Australian Nuclear Science and Technology Organisation (ANSTO), University of Toronto, SGS Lakefield, and ALS Brisbane with advisory assistance by KYSPYMet and Inception Group (now WGA).
In October 2022, AR3 entered into a non-binding memorandum of understanding (MoU) with Neo Performance Materials to expedite the development and take Koppamurra rare earth project towards production.
The MoU outlines terms on which the companies may sign an offtake agreement that will enable Neo to buy 50% of Koppamurra’s MREC capacity from the initial module.