High vanadium recoveries from King River’s Speewah ores

ASX listed vanadium developer King River Copper is firing on several fronts, as it seeks to identify the optimal and most commercially practical ore processing route for its mammoth Speewah vanadium-titanium-iron project in the east Kimberley region of WA.

The company reported this week that bottle roll leach test work on magnetite concentrates from Speewah, produced high leach efficiencies that extracted 92% of the contained vanadium, 76% of the iron and 19% of the titanium, after a 58-day cycle of sulphuric acid leaching.

According to King River, although leach rates for vanadium and iron had plateaued after 58 days, the rate of titanium leaching had actually picked up over time.

These initial bottle roll tests will provide baseline data and lead to more definitive metal recoveries using different sample masses and crush sizes for the ores.

The test work is expected to continue throughout October.

King River is also undertaking further laboratory-based leach test work of its ores using two further methods.

One method uses a hydrochloric acid leach to produce a commercial-grade +98% vanadium pentoxide flake product, using a modified version of the traditional AMV process route.

Results were very encouraging, with test work extracting up to 99.1% of the contained vanadium, nearly 89% of the titanium and up to 96.4% of the contained iron in the original sample.

A second method used a sulphuric acid leach for the flake test work stream, but metal recoveries were lower overall.

The company is conducting these diverse metallurgical test studies with the aim of assessing which processing routes, or alternatively combinations of routes, prove the most prudent to develop the ore deposits

King River owns the largest defined vanadium mineral resource on the planet at Speewah, which contains 4.712 billion tonnes grading 0.3% vanadium pentoxide, 2% titanium and 14.7% iron.

The company is very focussed on maximising the key variables of the Speewah deposits, which outcrop at surface and are 80m thick, 1-2km wide and have very low strip ratios for future open pit mining extraction.

Individual deposits strike over many kilometres at the project.

The company is completing numerous bench-scale definitive metallurgical test work studies to extract the maximum value from its flagship asset.

Specifically, King River is evaluating multiple ore processing options into the production of a premium vanadium pentoxide powder exceeding 99.5% purity and a standard-grade vanadium pentoxide flake product with a purity closer to 98%.

Additionally, the company is looking to maximise the value of its titanium dioxide products, where it is pursuing the development of a high-purity pigment grade material, with a grade exceeding 99.5% titanium dioxide.

There are also options to generate a high-quality iron oxide hematite product and a vanadium electrolyte material, the latter of which is a critical component used in the emerging vanadium flow battery sector for sustainable energy storage applications.

King River management said: “The evaluation of the best processing path to be taking to develop and/or market the Speewah deposits relies on the detailed process routes and studies currently being undertaken. Development planning may include the option to export portions of concentrate production.”

“While bottle roll sulphuric acid leaching testwork 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 V2O5, Fe2O3 and TiO2. Other potential by-products include processing the dumps to extract the residual ilmenite to produce TiO2, and possibly extract the Al and Mg from the leach solutions to make High Purity Alumina (HPA) and magnesium products.”

“The Board is … focussed on maximising the key strategic variables of the Speewah deposits, namely, 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 that enables the generation of a higher V2O5 grade concentrate compared to most peers.”

King River says it will release its vanadium scoping study for the Speewah deposits later this month.