Laboratory test work completed in 2019 in Brisbane indicated that a pelletised roast and water leach of vanadium rich concentrate from the company’s Australian Vanadium Project in WA can deliver improved vanadium extraction relative to traditional rotary kiln processing.
Between August and December 2019, a metallurgical test program involving pelletising and oxidative salt roasting was carried out in Brisbane.
The purpose of the program was to investigate the performance of the oxidative salt roast in a pot rig, which simulates a Grate Kiln.
3D model of Metso Grate Kiln showing travelling grate
About 587 kilograms of preliminary beneficiation concentrate was tested to characterise pellet performance, vanadium extraction, reagent usage and operating conditions for the Grate Kiln pilot testing scheduled at Metso in the first and second quarter of 2020.
Results of the bench-scale test work show:
- High-quality pellets, with the mechanical strength required to survive the roasting process, can be produced without additional binders or processing steps.
- Vanadium roast leach extraction was as high as 95.5%, varying between 86.9% at low roast temperature and 95.5% under optimised temperatures, bed depths and retention times. All tests were performed at 4% soda ash addition, which was the basis for the PFS. The particle size required for pelletisation was confirmed to be similar to the particle size of the final concentrate generated in the crushing, milling and beneficiation (CMB) pilot.
Vanadium rich iron concentrate pellets produced during bench-scale roast testing
AVL managing director Vincent Algar said: ‘AVL is increasing its competitive advantage through process innovation.
“Our vanadium ore is very well suited to the traditional salt-roast methods, but we see opportunity in our test work for processing improvements that could lead us to a world leading position when in production.
“Improved vanadium recoveries, coupled with the potential to reduce gas consumption and related operating cost reductions, further reinforces the project’s position as a desirable investment.
“Utilising the Grate Kiln technology, which is well-understood and with a proven track record in the iron ore, titanium and steel industries, is an innovation that our highly technical team has pursued as a result of the diligent test work they are undertaking.
“Improving the economics of our project is the company’s key driver as we take each step forward.”
Two-tonne sample of beneficiation circuit concentrate shipped to the US for Grate Kiln pilot testing