Australian Vanadium Limited (ASX: AVL) has added to its confidence in its namesake project with positive metallurgical testwork results to support its vanadium purification flowsheet for the Western Australia-based development.
Managing Director, Vincent Algar, said the testwork produced high purity, 99.4%, vanadium pentoxide (V2O5) from representative leach liquor using hydrometallurgical methods.
The testwork is part of the detailed flowsheet validation programme undertaken by the company and its consultants since the 2018 Pre-Feasibility Study (PFS) and follows up successfully on previous vanadium pentoxide results.
Test results have shown that the AVL process, using standard methods, has the capability to achieve high purity V2O5 throughout the life of mine,” Mr Algar said.
“This high purity product is comparable with the high purity vanadium products made by our established producer peers.
“This outcome comes from concentrating on thorough technical study work and using the process method improvements AVL has identified in that study work.
“Without doubt, this quality outcome further increases confidence in the Project.”
The metallurgical testwork programme is underway to optimise the final stages of the vanadium refining process, which includes precipitation and V2O5 production.
The vanadium purification tests have been performed on leach solution derived from roasted material produced in pilot scale testwork at Metso Outotec’s Dansville pyrometallurgical facility in the USA. The concentrates provided to Metso were in turn generated from pilot scale crushing, milling, and beneficiation testwork at ALS laboratories in Balcatta, WA. Feed materials to the pilot programme at ALS were made up from a blend of drill core designed to represent the average first five years and life of mine process feed.
The standard refining technique used in the production of vanadium pentoxide produces an intermediary chemical product called AMV (ammonium metavanadate), which was the basis of the PFS refinery flowsheet.
This process includes a desilication stage (aluminosilicate precipitation and solid liquid separation) prior to precipitation of AMV at slightly basic pH.
In parallel with AMV testwork on representative leach liquor, AVL has tested an alternative mature vanadium production route known as APV (ammonium polyvanadate).
The APV processing path is a direct precipitation and operates at lower pH and higher temperature. The APV testing indicates an improved vanadium recovery, a reduced ammonium sulphate reagent consumption and has generated a final product quality of 99.4% V2O5, which was independently verified by an accredited laboratory.
The vanadium flake product from the Australian Vanadium Project is expected to be of outstanding quality, comparable to high purity products from existing global producers.