The share price of King River Resources Limited (ASX: KRR) leapt by 22% after it announced a breakthrough in the refining process Speewah Specialty Metals (SSM) Project in the East Kimberley of Western Australia.
As part of an ongoing Prefeasibility Study (PFS) the company has been examining a new process route to produce high purity alumina (HPA), vanadium pentoxide (V2O5), titanium dioxide pigment (TiO2) and iron oxide (Fe2O3) products in a re-scaled operation for the PFS.
King River has now revealed it has made a breakthrough in extracting aluminium (Al) directly from the V, Ti, Fe, Al and Mg rich sulphuric acid leach solution as the first precipitation product.
This process development resulted from investigations into removing iron from the leach solution to facilitate the solvent extraction of vanadium (V) and titanium (Ti).
The company says it is now able to remove 95% of the Al as an intermediate compound and in a second step ~50% of the Fe and ~58% of the magnesium (Mg) 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.
Purification of the intermediate Al rich product has produced a 99.98% Al2O3 (3N8) HPA on calcination and washing (calculated on an oxide basis, where impurities are converted to oxides then subtracted from 100%). Optimisation testwork to improve HPA purity and efficiency is underway.
The company had previously been progressing flowsheet development where Al was to be the last metal extracted from the leach solution by solvent extraction or chemical precipitation methods. Testwork could not commence on Al extraction and HPA production until the V, Ti and Fe had been removed.
Testwork in the coming weeks will also trial the potential of the new HPA process to extract Alumina from the waste fraction (~70% of mined volumes) that is generated at the concentrate stage of the process. The grade of Al in the ROM material is 12.7% Al2O3, the magnetic concentrates (30% of mined volumes) typically grade ~7% Al2O3, and the non-magnetic waste fraction (70% of the mined volumes) grades 15-16% Al2O3.
The waste fraction is expected to be largely devoid of the Iron, Titanium and Vanadium that are acid consuming in the leaching process. This further process modification may provide the added advantage for a smaller scale start-up SMM project and its future scalability of V, Ti and Fe production in proportion to prices and demand.
In a statement to shareholders, the company’s directors said the change of project focus towards extracting HPA and the redesign of process route may deliver valuable improvements to project economics, and prove worthy of these delays.
“KRR is making positive steps in its PFS process to identify the best process route and scale for the SSM project,” it was stated.