The vanadium bearing magnetite ores are typically processed through either smelting producing vanadium bearing slag (co-production) or the primary processing using a salt roasting and leaching operation, called Salt Roast process.
Co-production typically involves smelting magnetite ore/concentrate during which titanium slag is eliminated while vanadium and iron ore report together in hot metal from which vanadium is recovered in the form of a slag with enhanced vanadium grades.
The vanadium slag is then further processed into final vanadium product through a salt roast and leaching process (The Salt Roast process).
Secondary production from sedimentary vanadium is largely found in oil residues or shales is recovered from catalysts used during the refining of some crude oils or ash. Sedimentary vanadium is also found in stone coal geological settings. About 12% of vanadium occurs in sedimentary form.
Vanadium is extracted from these sources is converted into vanadium pentoxide (V2O5) and trioxide (V2O3). Most pentoxide is converted into ferrovanadium or nitride for use in the production of several different types and grades of high strength steel.
Abenab Ore Processing
The ore at Abenab is Desclozite, a lead zinc vanadate (Pb,Zn)2(OH)VO4. It is easily recovered by simple crushing and gravity separation with grades up to 21% achieved after concentrating. Titano-magnetite ores typically produce 1-3% V2O5 after concentrating.
Capital costs for concentrator and refinery are lower due to the simplicity of the gravity separation process and a higher grade concentrate that is produced. The refining process is less complex (low energy and reagent use) with the ability to treat through chemical based refineries compared with the large complex metallurgical processing with high energy use required for Titano-magnetite.
The by-products include lead with and zinc with grades up to 53% and 14% respectively.