The new results support advancing the new specialty metals project development plan for Speewah, which includes on-site processing of high purity products and the potential for scalability and cost savings.
King River chairman Anthony Barton said: “The board is most 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.”
Flooded column leach setup
The heated flooded column leach test work used 20% sulphuric acid on 5.6 millimetre lump magnetite gabbro, reporting 90% vanadium and 47% titanium extractions after 14 days.
Comparative heated microleach testing also used 20% sulphuric acid on 106 micron magnetite-ilmenite concentrate and showed 97% vanadium and 62% titanium extractions after 3 days.
King River will progressively transition laboratory test work towards more diagnostic vat leach tests as well as work to extract the metals back out from sulphuric acid leach solutions.
Methods to be trialled include solvent extraction, ion exchange, thermal hydrolysis and chemical precipitation.
Barton added: “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.
“During 2019, 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.
“[This includes] vanadium, titanium, iron and other high-value products at the lowest possible unit cost.”
Metallurgical work to be addressed in the Speewah specialty metals plan include:
Completing vat flooded column leach test work to examine the effects of changes in temperature, acid concentrations and flow rates;
Further hydrometallurgical process flow sheet development;
Beneficiation plant design and capital and processing cost estimates;
Capital and operating costs for vat leach operation, comparing lump and concentrate scenarios’;
Options analysis into capital and operating costs for an on-site sulphuric acid plant;
Geotechnical studies on drill core to support final pit design; and
Environmental, heritage and marketing studies.