Australian Vanadium’s combined roast and leach extraction testwork has successfully validated 92% vanadium recoveries from its namesake project.
The removal of 99% of soluble vanadium from the iron-titanium coproduct has also enhanced its value for direct use in steel-making, which could further improve the economics of the project.
Australian Vanadium’s (ASX:AVL) testing also validated its mechanical water leach circuit as a viable, cost-effective design that maximises onshore extraction of high-value critical mineral vanadium products.
“The success of this phase of the water-based leach of AVL’s pelletised concentrate compares very favourably to other global operations that process vanadium from vanadium titanium magnetite deposits,” managing director Vincent Algar said.
“Combined roast/leach extractions reported elsewhere are generally under 90%, with extractions usually in the low to mid 80s, supporting a significant advantage for the Australian Vanadium Project, having demonstrated overall vanadium extraction of 92%.
“These latest positive outcomes finalise key technical aspects of the BFS flowsheet design. A robust and well supported process engineering design pushes AVL further ahead towards the successful commencement of the project.”
Exciting news given projections that the vanadium market could be in deficit until 2024.
Pilot process
Australian Vanadium’s process is divided into two stages with the first pilot stage of a rotating drum leach on a salt-roasted vanadium concentrate running in May 2021.
This recovered most of the vanadium in the plant feed.
Leach residue from the first stage was then tested in 1 metre columns to simulate a counter-current washing process, where the remaining vanadium and soluble metals are removed from the iron-titanium coproduct for an overall soluble vanadium extraction of 99%.
These and ongoing scaled up column water-wash test results will be used to model the final circuit design.
Full-scale design is expected to be a series of water irrigated stockpiles of iron-titanium coproduct, arranged in a counter-current format.
Next steps
The company noted that sufficient data has been gathered to set the leach flowsheet and commence the associated engineering design and layout activities for the bankable feasibility study.
Work has also started on open circuit testing of a 5.5m column leach and will soon be followed by testing in counter current mode.
These additional tests are designed at the full scale proposed heap height to confirm optimised leach conditions and scale up relationships from the 1 metre column counter-current program, allowing the company to finalise the mass, energy and water balance for its leach process to a higher level of certainty.
Samples of iron-titanium coproduct will be sent for blast furnace customer testing in Asia while vanadium pentoxide products will be analysed and used for specific customer testing in vanadium redox flow battery and specialty chemical applications.
This article was developed in collaboration with Australian Vanadium, a Stockhead advertiser at the time of publishing.
This article does not constitute financial product advice. You should consider obtaining independent advice before making any financial decisions.