Metallurgical process
All vanadium in the ore occurs in solid state in the titaniferous magnetite. The first stage of processing is to concentrate this magnetite by crushing, grinding and low intensity wet magnetic separation. The magnetite concentrate is then subjected to a conventional roast leach precipitation process for the recovery of vanadium as Vanadium Trioxide (V2O3) or Vanadium Pentoxide (V2O5).

Mining
Vanadium containing magnetite is open-cast mined.

Crushing
Coarse ore is tipped from mine trucks over a grizzly. Ore passing over the grizzly feeds a Jaw Crusher, and conveyor then feeds the product to the Autogenous (AG) Mill.

Grinding and Wet magnetic Separation
The AG Mill discharge is fed through a hydrocyclone to a wet magnetic separator. The non-magnetics are pumped in slurry form to the slimes dam while the magnetics gravitate to the Ball Mill. Ball Mill discharge is fed via a hydrocyclone and a hydrocone to cleaner magnetic separators. The magnetic product from the cleaner magnets is filtered on a belt filter to form a magnetite concentrate stockpile.

Roasting
The purpose of the roasting stage is to convert the Vanadium occurring in solid solution of the titaniferous magnetite to water-soluble sodium vanadate. Magnetic concentrate is reclaimed from the stockpile using a feeder arrangement and conveyors. Calcine discharges from the kiln onto a grizzly. Oversized material is stockpiled, re-crushed and returned while undersized material passes to a cooling conveyor. The calcine discharges from the end of the cooling conveyor into a quenching box equipped with a scrubber.

Leaching
Calcine is fed to one of three leach vessels where the porous calcine is leached with water. Filtration is achieved through the calcine itself. During filling and emptying, the calcine is spread evenly. The solution produced, containing the Sodium Vanadate is called the pregnant solution.

Desilication and Precipitation
To achieve the desired final product quality, Silica (SiO2) is removed from the pregnant solution. This is achieved by using Aluminium Sulphate (Al2SO4) and filtering out insoluble silica. Precipitation of Vanadium from the pregnant solution is achieved by the addition of Ammonium Sulphate ((NH4)2SO4).

Barren Solution Handling
The vanadium recovery process makes use of an evaporation process to recover sodium sulphate salt from the barren solution after precipitation. This salt is recycled back to the kiln, displacing the need for a portion of the sodium carbonate flux requirement.

Ammonium Vanadate Processing to V2O5 flakes and dry AMV
The ammonium metavanadate solids precipitated is filtered. The precipitated AMV is either directed toward a drier or deammonitator. In the drier the moisture of the AMV is driven off and then transferred to the V2O3 reactors.

The balance is fed into the deammoniators where the ammonium ions are driven off to form V205 powder. The powder is then melted in a liquid fuel fired furnace, cooled on a flaking table to produce V2O5 flakes.

Ammonia gas given off in the drying and deammoniation processes are scrubbed with water and neutralised with sulphuric acid to form ammonium sulphate which is recycled for use in the precipitation section.

Ferrovanadium Production – Alumnothermic Process
The production of FeV by Aluminothermic reduction process requires the addition of V2O5, aluminium, lime and iron scrap mixed together and placed in a refractory lined ladle. The ladle is ignited with the reaction being fully autogenous. On completion of the reaction, the FeV has collected at the bottom of the ladle and a high Al2O3 slag forms above the FeV.

After cooling, the slag and metal are separated. The FeV is crushed, sized and packed to customer requirements. The slag is crushed, some of the slag recycled back into the process and the balance sold. All fumes generated in the process are collected in a gas cleaning plant and recycled.

Ferrovanadium Production – DC Arc Furnace
The DC arc furnace is used to produce 80 % vanadium contained ferrovanadium which is crushed and shipped to customers. The furnace requires the addition of vanadium trioxide, aluminium, lime and scrap iron to produce the ferrovanadium product.

Although the reaction between vanadium trioxide and aluminium is exothermic, the reaction still requires additional electrical energy which is supplied by the DC furnace. After completion of the furnace melt, metal and slag are tapped out of the furnace into a tap pot. After a cooling and solidification period, the pot is emptied and metal and slag is separated. The furnace is fitted with a baghouse to collect the fumes during the smelting process.