The other reason for providing this information from Largos is, of course, SYR has in it's recent announcement referred/compared it's project to that of Largos/Maracas - see below. SYR used data extracted from a report dated July 2011. The information I provided links to is more up-to-date i.e. 2013. ------------------------------------------------------------ Extract from SYR ann:-
The highest grade vanadium deposit in the world is said to be Largo Resources’ (TSX: LGO) Maracas project in Brazil (Ocean Equities Vanadium Sector Review 15 July 2011). Maracas has a Mineral Reserve of 17.2 million tonnes at 1.44% V2O5 and is slated to come in to production later this year. Largo has signed an offtake agreement with Glencore, the world’s largest vanadium producer to take 100% of the production for the initial 6 years of production at Maracas. ------------------------------------------------------------
The 2011 Report does also give some good information on the mining/extraction processes...
Predominantly open pit mines.
Mining and Extraction – Processing Costs High The majority, if not all, of the world’s vanadium mines are amenable to open pit mining. Vanadium bearing minerals are treated by means of several processes such as calcination reduction, roast/leach, solvent extraction and ion exchange to recover vanadium either as metal, ferro-vanadium (FeV), vanadium pentoxide (V2O5 or “blackflake”), or in the form of various chemicals. Pure vanadium is difficult to produce since it is readily contaminated by many other elements.
Beneficiation into a magnetite concentrate is the first step in processing.
Titaniferous Magnetite Processing Titano-magnetites are the main source of ore feedstock for the recovery of vanadium products. A key characteristic in the first stage of processing into a concentrate is the grade or ‘tenor’ of vanadium. As we discuss in “Project Considerations”, page 19, this can vary from >1% V2O5 (e.g. Balla Balla deposit),up to over 2.2% V2O5 (e.g. Speewah deposit).
Stage 1: Beneficiation for a Magnetite Concentrate The first stage of processing is to concentrate this magnetite by crushing, grinding and low intensity wet magnetic separation.
Salt roasting and water leaching produce vanadium oxides. A circuit to generate FeV products is the final step.
Stage 2: Salt Roasting and Water Leaching The magnetite concentrate is then subjected to conventional salt roasting followed by water leaching processes for the recovery of vanadium as vanadium trioxide (V2O3) or vanadium pentoxide (V2O5) (For example as at Xstrata’s Rhovan operation, flow sheet Exhibit 1). This process is both capital intensive and generally has a high operating cost attached. The cost of suitable sodium salts, availability of capital and increasing energy costs and energy availability are critical factors in determining the viability of vanadium developers.
Stage 3: FeV Production and Additional Circuits The addition of a ferro-vanadium circuit either to convert vanadium pentoxide (V2O5) to ferrovanadium (FeV80) or generate it directly through a vanadium trioxide route, V2O3 as the final product or as part of a mixed product stream is becoming more common. Usually this will add significant value to the project because the ferro-vanadium product achieves a price premium over vanadium pentoxide.
New Processing Techniques - Hydrometallurgical The alternative for processing titano-magnetites is by way of a hydrometallurgical process. This has been explored in the past; however, the challenge has been minimising the dissolution of iron in leaching without sacrificing the extraction efficiency of vanadium. The limiting factor in the process is being able to selectively separate the vanadium from the iron.
The basic process involves acid leaching combined with solvent extraction and stripping to selectively recover units of vanadium, along with titanium and iron from the magnetite concentrate. Developers exploring this technology include Speewah Metals (ASX:SPM) and TNG Ltd (ASX:TNG). Once the selective separation of the metals can be enhanced in this process, the technology has the potential to serve as a cost effective alternative to the more traditional pyrometallurgical process, also adding other valuable revenue streams from titanium and iron products.
Vanadium slags are traditionally produced as a co-product in uranium processing.
Processing Vanadium from Sediments – Different to Magnetites The vanadium hosted in sediments and sandstones typical of the US are commonly mined firstly for uranium then vanadium as a co-product. The processing of these ores requires solvent extraction to separate the vanadium and uranium fractions which is then followed by an ion exchange stage which leaves the vanadium in the acid solution. The acidic solution is oxidised to allow the recovery of vanadium from the organic salts by means of soda ash. The resultant slag produced then undergoes a similar pyrometallurgical process to recover FeV and V2O5 for different uses.
Emerging players in the vanadium sector that are investigating sedimentary hosted deposits of vanadium (different to uranium-vanadium sedimentary deposits) include: Energizer Resources (TSX:EGX) with its Green Giant deposit in Madagascar; Sino Vanadium (TSX:SGX) with its Daquan project in China; and American Vanadium (TSX:AVC) which owns the Gibilleni deposit in Nevada, USA.
SYR Price at posting:
$2.63 Sentiment: None Disclosure: Not Held
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