King River Resources Ltd (ASX:KRR) is continuing to advance its Speewah Specialty Metals Project (SSM) in the east Kimberley region of WA with further process optimisation work underway to improve recoveries, as well as test work to verify the grade.
The company plans to initially scale the SSM project to produce high purity alumina (HPA) with vanadium, titanium, and iron as potential co-products at a later stage – but not included as part of the PFS.
This is expected to significantly reduce the size of the project, with the potential to reduce the capex and maximise returns.
The project is 110 kilometres southwest of Kununurra
Prefeasibility study update
During the June quarter, King River announced further updates on metallurgical test work and activities to complete its PFS.
This included the following hydrometallurgical test work and flowsheet development results:
- The calcination of the HPA precursor at 1200°C has helped reduce transfer losses and aluminium previously lost on final wash, which is expected to convert the HPA product to alpha-alumina;
- During the stag- 2 purification precipitation, recovery of 81.5% aluminium was achieved with the target recovery for this stage of the process set at 80%; and
- Solvent extraction test work is underway to produce vanadium oxide, titanium and iron oxide products using leachates from the magnetic magnetite-ilmenite concentrates.
King River’s mining study by CSA Global is complete, in addition to the marketing and environmental reports.
Como Engineers plant and infrastructure design and costings are largely completed with the company still waiting on the final model validation and review.
Breakthrough in extracting aluminium
In April King River produced the first >4N (99.99% aluminium oxide) HPA by a new process developed metallurgical consultants TSW Analytical Pty Ltd.
TSW made a breakthrough in extracting aluminium directly from the vanadium, titanium, iron, aluminium and magnesium-rich sulphuric acid leach solution as the first crude aluminium-rich precipitation product from which 99.98% aluminium oxide HPA was produced.
Subsequent refinement of the crude aluminium precipitation process has resulted in Al precipitation efficiencies up to 95% and understanding how to reduce the amount of reagent used in the Al precipitation process.
The aluminium rich precipitate from the leachate was purified by a two-stage purification process to reduce contaminant metals to very low levels in a precursor product suitable for the production of 4N HPA. Stage-1 Recrystallisation process recovers 95% aluminium and Stage-2 involves an Ion Exchange process that further removes contaminants.
King River started a 2,000 metre RC drilling program at its Tennant Creek Gold Project in the Northern Territory on August 9, following up on encouraging geophysical results returned from 2019 geophysical surveys.
The company will also begin reconnaissance exploration to progress other priority targets for drilling.
Drilling program details
Drilling at the Lone Star area will target-3 main coincident gravity and magnetic trends.
The strength of the magnetic and gravity anomalism of these targets is comparable to other known Iron Oxide Copper Gold (IOCG) deposits in the area.
Notably, Emmerson Resources Ltd (ASX:ERM) Mauretania deposit is only 700 metres from the western boundary of KRR’s tenement where 20 metres at 38.5g/t gold was returned in a diamond drill hole last year.
Drilling will then move to the Commitment Prospect where a large coincident magnetic and gravity anomaly follows a NW/SE trend.
The program is set to target the main magnetic body as well as a strong gravity anomaly slightly offset from the main magnetic body possibly representing a hematite rich zone.