The test work is aimed at identifying the most optimum and commercially-practical process routes for King River to pursue in the development Speewah’s vanadium-titanium-iron deposits.
This work on different process methods will provide data for a trade-off analysis to demonstrate a clear path forward as part of Speewah’s future pre-feasibility study.
King River said the evaluation of the best processing path to develop and market the Speewah deposits relies on the detailed process route and studies currently being undertaken.
While bottle-roll sulphuric acid-leaching test work is at a very early stage, KRC plans to examine the opportunity to heap or vat-leach lump material, or a coarse-grained concentrate, to extract vanadium pentoxide, iron oxide and titanium dioxide.
Other potential by-products include processing the dumps to extract the residual ilmenite to produce titanium dioxide, and possibly extract the aluminium and magnesium from the leach solutions to make high-purity alumina (HPA) and magnesium products.
King River's two projects in northern WA
The company’s board is focused on maximising the key strategic variables of the Speewah deposits, which it names as:
Their massive size;
The outcropping, flat-lying geometry;
The overall consistency of grades amenable to large-scale mining methods; and
The unique tenor of the magnetite, enabling the generation of a higher vanadium pentoxide concentrate grade compared to most peers.
Test work has been conducted into the production of high-purity vanadium pentoxide powder (plus-99.5% vanadium pentoxide) and standard-grade vanadium pentoxide flake (plus-98% vanadium pentoxide).
Other metallurgical research includes investigating the production of titanium dioxide products (pigment grade and high purity plus-99% titanium dioxide), iron oxide hematite and vanadium electrolyte which is used in vanadium flow batteries.
A bottle-roll sulphuric acid leach test was completed by Nagrom Metallurgical, designed to provide baseline data on what metals leach under the best conditions such as acid concentration, fine grain size, agitation, high metal mineral content and relatively-low acid-robbing minerals.
The leach test also assessed the suitability of this sulphuric acid leach for column or vat leach tests on lump material and concentrate types, with or without agglomeration.
Nagrom is undertaking further bottle roll tests on diamond core samples of magnetite gabbro with three different lump sizes.
After 12 days the vanadium and titanium are leaching slowly, with high leach rates for iron, aluminium and magnesium.
These leaches will continue into October when a decision will be made to continue the leaches and/or start a leach of a coarse-grained concentrate.
Additional magnetite-ilmenite concentrates are also being produced by Nagrom, using magnetic and gravity separation methods from metallurgical core, for use in hydrometallurgical tests.
These concentrates are from both the high-grade and low-grade zones of the magnetite gabbro as well as of different grind sizes suitable for different processing routes.
Laboratory test work utilising hydrochloric and sulphuric acid leach is being undertaken by TSW Analytical and King River has appointed ALS Metallurgy to complete salt roast-water leach-AMV testing to produce vanadium pentoxide.