King River Resources Ltd (ASX:KRR) continues to enhance a pre-feasibility study (PFS) assessing the production of high-purity alumina (HPA) from Speewah Specialty Metals Project in the Eastern Kimberley region of Western Australia.
The PFS has retained a Kimberley focus that will produce HPA with any potential co-products vanadium, titanium and iron not included in the initial study.
Additional PFS work
Following an update on the PFS in September, additional development works have been the focus of test-work and studies including:
- The company’s metallurgical test-work using its simplified purification process has produced a high purity precursor compound with the main contaminant metals each at very low levels (about 1ppm or less than 1ppm) - this precursor may be suitable for the production of 4N (99.99% Al2O3) HPA after calcination (heating to 1200°C) and washing;
- Calcination of the HPA precursor (at 1200°C) is the current focus of test-work to ensure no contamination is introduced during the heating process and 4N (99.99% Al2O3) HPA is produced;
- First batch of HPA samples of different alumina grades produced in previous test runs has been submitted to an independent umpire laboratory to provide greater confidence in test-work assays and help identify sources of contamination in the test-work;
- CSA Global has updated the mining study based on the simplified flowsheet with improved overall recovery and lower throughput;
- CRU International is finalising the HPA market study to a 2028 dateline; and
- Como Engineers is working on completing the process plant and infrastructure design and costings based on the updated flowsheet and the final production of 4N HPA.
King River aims to release the PFS as soon as practicable upon completion of these remaining outcomes.
Additionally, the company is continuing to progress metallurgical test-work and engineering studies using its HPA process route on alternative aluminium feedstocks.
Test-work has demonstrated that a high purity HPA precursor can readily be made with fewer process steps.
The implication is that start-up HPA development may be initially focused on a Perth industrial estate without the immediate capital and permitting needs of building a Kimberley-based acid plant adjacent to a mining and processing operation.