Highlights
- Edith Cowan University Mineral Recovery Research Centre (MRRC) complete phase 1 Mt Edon rubidium extraction test works
- MRRC laboratory results develop a technically viable direct rubidium extraction method and support for next step rubidium purification processing into final rubidium products
- Development of grant application commenced for scale up pilot plant processing
- Mt Edon maiden JORC Resource imminent
- Further infill drilling planned in Q4 2024
Everest Metals Corporation Ltd (ASX: EMC) (“EMC” or “the Company”)is pleased to announce the initial results of successful extraction of Rubidium from the Mt Edon mineralised material in a small-scale laboratory setting.
“These initial results demonstrate technically viable high recovery 75±10% of Rubidium by Direct Extraction method. Next phase purification works are ongoing into final products. We thank MRRC for their excellent progress which was completed ahead of schedule. The laboratory test work underpins the commencement of an assessment of a variety of Global Critical Mineral processing grants available as development funding for next Phase Pilot Plant scale up.”
EMC’s Executive Chairman and CEO Mark Caruso commented:
THE RESEARCH & DEVELOPMENT AGREEMENT
On 26 February 2024 Edith Cowan University (“ECU”) and EMC executed a Research Agreement (“Agreement”) for studies in relation to the Extraction of Rubidium from Mt Edon pegmatite[1]. The research activities undertaken at ECU’s Mineral Recovery Research Centre (“MRRC”) were estimated to take place over a 10-12 month period.
The first stage of the collaboration between EMC and MRRC involved a small-scale laboratory demonstration of all the processing steps in the recovery of Rubidium. The Direct Rubidium Extraction (“DRE”) test work and studies utilised advanced processes such as ion exchange. The project focuses on extracting the Rubidium from Mt Edon ore using a Direct Rubidium Extraction technology. Due to the increasing need for sustainable and environmentally friendly extraction processes, these studies aim to develop a state-of-the-art extraction technique that maximise the recovery of Rubidium and mica. By selecting suitable Cations (a positively charged ion) and optimising operating conditions, the project aims to achieve maximum Rubidium extraction by utilising a cost effective and environmentally friendly method. This approach leverages cutting-edge technologies, innovative methodologies, and industry best practices to ensure a sustainable and profitable extraction process. The process encompasses purification and refining, ultimately leading to the conversion into a final product such as Rubidium salt, metal and potentially mica.
Under the Research agreement any intellectual property (“IP”) rights deriving from the project will be owned by EMC. As part of this study, critical assessment of the feasibility and potential enhancements of the Direct Rubidium Extraction method will be done. This will allow EMC and ECU to jointly apply for the Cooperative Research Centres Projects (“CRC-P”) Grants, Australian Research Council’s (“ARC”) Linkage Program, etc. to scale up the process technology.
The Company expenditure for this project will be eligible for Federal Government Research and Development (“R&D”) Tax Incentive.
Details of Test work
Two process methods of non-destructive and destructive were used to extract Rubidium and Lithium. Various test work was conducted by ECU’s MRRC with results demonstrating acceptable levels of both Rubidium and Lithium in the leach liquor. During process development, special attention is given to potential by-products and to industrial minerals such as quartz, mica and feldspar which may be recovered during mineral concentration, leaching and purification.
Associate Professor Amir Razmjou, the ECU team lead, stated, “The Rubidium extraction process is progressing well ahead of plan, and we are excited to move toward purification of the Rubidium in the next step.”
In the non-destructive method, the structure of muscovite remained unchanged. Two sets of acidic and non-acidic experiments were performed, and X-Ray diffraction analysis (XRD) was conducted on the samples before and after the tests to explore the structure of the solid powder. In non-acidic tests, low acid concentrations of the sample were prepared to enhance Rubidium extraction. In this stage of the project, multiple tests were performed and most of the experiments repeated two or more times. Inductively Coupled Plasma Mass Spectrometry (ICP-MS) was used for assay.
Five different chemical compounds were utilised in this set of tests. Some of these chemicals were used only during the non-acidic experiments. Since this set of experiments was conducted without acid, the impact of time of chemicals reacting with the sample and temperature were also investigated for the sake of optimisation.
During acidic tests, all chemical compounds were used with different concentrations of acids whilst maintaining a similar methodology. The effect of different concentrations of acid and various temperature ranges were examined in this stage. The results indicated that with the application of acid the maximum achievable Rubidium extraction is about 41%. Unwanted cations showed different behaviours while using different chemicals as their extraction depended on the presence of various ions within the solution. In most cases, lithium ions were extracted in a low quantity that is manageable.
In the destructive method, the muscovite structure was deteriorated to gain the maximum extraction of Rubidium. Different acid types and different concentrations of acids were utilised in this phase. Several tests were also conducted in this stage and repeatability of the results were checked to attempt to achieve the same results again. The maximum Rubidium extraction achieved in this stage demonstrates repeatability within a range of 75±10%.
Due to the different cations available in the muscovite structure, the colour of the leaching liquid could change based on the concentration of different cations available within the sample. Figure 1 shows some of these samples as a visual representative of different cations.
Figure 1: Effect of different tests on the colour of the solution, representative of different extraction levels, a) acid leaching, b) acid and salts mixture leaching
Next steps
Additional test work is currently underway. EMC anticipates reporting results from the various ongoing extraction and purification tests in the December 2024 quarter. The outcome of these tests will offer essential technical and performance data, facilitating a scoping study with a view to then constructing a pilot-scale plant.
The recent mineralogical studies indicated that muscovite (White Mica) can source the highest average Rubidium contents within its structure, averaging 7,600 ppm Rubidium (0.67% Rb). The next highest average Rubidium contents are from K-feldspar with ~5,000ppm Rb[2]. The Company is continuing geometallurgical testing and mineralogical studies to characterise the mineral assemblage of rubidium-bearing minerals at the Mt Edon pegmatite, alongside extraction metallurgical testing at ECU’s MRRC through the Direct Rubidium Extraction method.
Project Development
EMC has established a phased approach to advance the development of rubidium (Rb) production from its Mt Edon Critical Mineral Project. The Company expects to release a maiden JORC Mineral Resource at Mt Edon in August 2024. An environmental scoping study has been undertaken and fauna and flora baseline surveys planned EMC is planning environmental studies, including Flora and Fauna assessments, and is preparing the necessary documentation for the Mining Proposal. The Company aims to obtain all required approvals by the end of 2025.
Figure 2: Mt Edon Critical Mineral Project Milestone
[1] ASX: EMC;EMC To Advance Mt Edon Critical Mineral Project Through Rubidium And Industrial Mica Product Development, dated 27 February 2024
[2] ASX: EMC announcement; Mt Edon World Class Rubidium Critical Mineral Project – Update, dated 1 July 2024
