The company’s deposit comprises a measured, indicated and inferred mineral resource of 4,712 million tonnes at 0.3% V2O5, 3.3% TiO2 and 14.7% iron – making it Australia’s largest vanadium-in-magnetite deposit.
King River Resources Ltd (ASX:KRR) has achieved a key milestone in its specialty metals strategy by producing a high purity titanium dioxide product assaying 99.73% during ongoing testing.
This comes as part of test-work aimed at developing a flow-sheet for the production of high-purity vanadium pentoxide, vanadium electrolyte and titanium dioxide products used in the manufacture of vanadium flow batteries, master alloys and titanium oxide pigments.
Hydrometallurgical test-work by Perth-based Nagrom Metallurgical has resulted in the titanium dioxide product from KRR’s 100%-owned Speewah Specialty Metals Project (SSMP) in the Kimberley of Western Australia.
Solvent extraction and hydrolysis precipitation
The initial focus of Nagrom’s product generation test-work has been the precipitation of a titanium oxide (TiO2) product by solvent extraction (SX) and hydrothermal methods.
Magnetite-titanium magnetic mineral concentrates from three diamond core holes in the central deposit were leached in sulphuric acid under various test conditions to produce nine leachate solutions (AVL14-22).
The leach liquors were combined to provide 5L for the SX-Hydrolysis test-work.
In the first SX stage, the titanium was extracted from the leachate by loading onto an organic extractant-diluent mix optimal for the leachate composition and highly selective for Ti.
In the second SX stage, a stripping test was run on the loaded organic to scrub impurities such as iron from the organic phase.
The last stage of the SX process involved another stripping test on the scrubbed organic to extract titanium.
Further test-work required
A feed solution from the stripping tests, comprising 1g/L iron e and 1g/L titanium was used in a purification investigation involving hydrolysis to produce a synthetic Crude TiO2 precipitate.
The test work resulted in the production of a high purity TiO2 calcine product that assayed 99.73% TiO2.
The main contaminants were 120ppm Si, 90ppm Na, 70ppm S, 30ppm K, 30ppm Ba, 21ppm Zn, 15ppm Fe, 10ppm P, and 5ppm Al and Sn, with 0.3% Loss on Ignition (LOI). V was <1ppm.
Further test-work is required to refine and optimise the process, improve Ti recoveries, and increase the titanium dioxide purity by reducing LOI.
Solvent extraction of vanadium pentoxide
SX test-work has identified a suitable organic extractant and diluent to extract vanadium from the sulphuric acid leach liquors at high V selectivity.
Testing is underway using the Ti-depleted leach liquors used in the titanium test-work and will be reported on successful completion.
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