Australian Vanadium Limited (ASX: AVL) has selected world-renowned industrial company Metso Corporation to assist with the next phase of the Definitive Feasibility Study for the company’s vanadium roast pilot plant.
To be undertaken at Metso’s Danville, Pennsylvania facilities in the USA, the pilot study will look to develop an improved thermal processing solution involving pelletising of the vanadium rich iron concentrate produced at AVL’s Australian Vanadium Project.
The solution will involve pelletising the concentrate and processing it through a GK system. Pelletising has been used previously in Europe and China for the processing of primary Vanadium-Titanium-Iron ores. The benefits of pelletising include:
- improved roasting reaction;
- minimal dusting; and
- reduced build-up of residues within the kiln.
AVL reported that it has already completed bench-scale tests on its pelletised vanadium rich iron concentrate and these have confirmed that pelletised concentrate roasting offers a substantial advantage to the traditional rotary kiln technology currently employed by all primary vanadium producers.
The company said its pelletised roasting tests have shown vanadium extraction results averaging 95.4%, versus a rotary kiln extraction of 85-88%, which is typical of standard vanadium roasting technologies1.
The next phase calls for pilot scale testing to simulate and optimize the GK process. The GK system is a combination of a travelling grate furnace for pre-processing with a rotary kiln for final roasting.
The feed concentrate is formed into pellets of a particular size that are well-suited for the process. The pellets are then loaded onto the traveling grate and pass through multiple furnace heating zones where progressively hotter and hotter gases from the kiln are forced through the bed of pellets.
This process accomplishes gradual and controlled drying and preheating of the pellets while recouping much of the energy from the hot kiln exhaust gases. The rotary kiln is then dedicated to the final roasting of the pellets after they’ve been dried and preheated and can be controlled independently to achieve thermal profiles which result in higher levels of vanadium extraction.
AVL’s Chief Operating Officer, Todd Richardson, said Vanadium roasting technology has not changed much since the 1930s, when cement kiln technology was adapted for salt roasting vanadium bearing ores.
“Since that time, the technology has gone largely unchanged. By partnering with Metso, a world leader in pyrometallurgical processing, AVL is confident that the roasting process can be greatly improved.
“Industry standard vanadium extraction is 87% in roasting, but AVL test work shows that much higher recoveries are possible by applying newer roasting technologies. Recovering these lost vanadium units has a large impact on project economics.”