King River Resources has extracted up to 97% vanadium in heated sulphuric acid vat leaching metallurgical test work on mineral concentrates from its massive Speewah specialty metals project, located near Kununurra in the Kimberley region of WA. The company previously stated that the results support an alternative ore processing route for its flagship project that could drastically lower capital and operating costs.
King River Resources has provided a further update on metallurgical test work underway on ore composites for its Speewah specialty metals project, located in the East Kimberley region of WA.
New results from heated flooded column leaching studies on vanadium-rich magnetite gabbro lump materials reported 90% extraction of vanadium and 47% extraction of titanium after 14 days of dissolving in heated sulphuric acid vats.
By comparison, leaching tests on the finer grained magnetite-ilmenite concentrate reported 97% extraction of vanadium and 62% extraction of titanium after only three days of dissolution under the same conditions.
King River said that both the lump and mineral concentrate leaching test work shows high metal extractions in the early stages of dissolving in the heated acid solvent.
Accordingly, the company added that the positive new results supported advancing the specialty metals project development plan for its future Speewah ore stream.
This could result in on-site sulphuric acid vat leaching and processing of vanadium pentoxide, titanium dioxide, iron oxide and other high-purity products as market demands dictate.
There is also potential to manufacture sulphuric acid on-site, which produces surplus heat that could be captured for electricity generation, heating of column vats and even process evaporation for crystallising the valuable mineral salts.
Laboratory scale test work will now progressively shift towards more diagnostic vat leach testing and precipitation of the metals back out from the sulphuric acid leaching solutions.
These studies will support a PFS for the specialty metals project, which is expected to hit the streets in the third quarter of this year.
King River management said: “The board is … encouraged by the new vat and column leach test results, particularly the flooded column result as it most closely resembles a vat leach operation. Successful conclusion of the tests will allow us to finalise the vat leach plant design and costings as soon as possible.”
“A trade off analysis into the optimum particle size will be undertaken. This will examine the merits of both a vat leach operation using lump magnetite gabbro compared to an agitated tank system using concentrate.”
“… KRR aims to present shareholders with the most prudent commercial strategy to develop the Speewah vanadium deposits and advance towards the production of a basket of specialty products, including vanadium, titanium, iron and other high value products at the lowest possible unit cost.”