King River Resources Ltd (ASX:KRR) has made a breakthrough in the refining processes being tested as part of an ongoing pre-feasibility study (PFS) for the Speewah Specialty Metals Project in WA by producing aluminium as an intermediate product from which 99.98% High Purity Alumina (HPA) has been produced.
The company has been examining a new process route to produce HPA, vanadium pentoxide, titanium dioxide pigment and iron oxide products in a re-scaled operation for the PFS.
King River is now able to remove 95% of the aluminium as an intermediate compound and in a second step about 50% of the iron and around 58% of the magnesium in a simple process that has the potential to be relatively low cost using readily available reagents and operates at leach temperature and atmospheric pressure.
Test work to trial new HPA process
Test work in coming weeks will trial the potential of the new HPA process to extract alumina from the waste fraction generated at the concentrate stage of the process.
Further process modification may provide the added advantage for a smaller scale start-up Speewah project and future scalability of vanadium, titanium and iron proportional to prices and demand.
The waste fraction is expected to be largely devoid of the iron, titanium and vanadium that are acid consuming in the leaching process while removing around 50% of the iron early in the refining flow sheet design is expected to facilitate the solvent extraction of vanadium and titanium .
King River had previously been progressing flowsheet development where aluminium was to be the last metal extracted from the leach solution by solvent extraction or chemical precipitation methods.
Test work could not commence on aluminium extraction and HPA production until the vanadium, titanium and iron had been removed.
Changes in the PFS process design to focus on HPA, with vanadium, titanium and iron co-products, is expected to deliver a positive impact on the economics of the Speewah project.
The drilling of the Junction vanadium deposit on the granted M80/267 mining lease provides further optionality for the development and timing of the project.
While recognising and appreciating the frustration and disappointment of shareholders with delays in completing the PFS, the KRR Board said the change of focus towards extracting HPA and the redesign of the process route may deliver valuable improvements to project economics and prove worthy of these delays.
The company said it was making positive steps in its PFS process to identify the best process route and scale for the Speewah project.