The TiVAN® testwork program was carried out at the world-class Commonwealth Scientific and Industrial Research Organisation (CSIRO) hydrometallurgical research facilities in Perth, with the appointed team of CSIRO experts providing significant input and improvements to the process before and during the trial. Selected photos from the testwork are included at the end of this release.
The program has confirmed the ability to achieve commercial vanadium recoveries of > 93% and produce high-purity vanadium pentoxide (V2O5) of > 99% purity, with high-purity iron oxide and titanium dioxide also recovered as valuable by-products.
An important development arising from these improvements is a significant improvement in titanium dioxide recoveries to > 90%, and the ability to obtain a low iron titanium dioxide concentrate of up to 65% purity. This has resulted in TNG and its consultants considering the production of titanium pigment (>90% grade) directly from this concentrate using an industry standard chloride process, allowing the Company to benefit from improved revenues. Titanium pigment currently sells for approximately US$3000/tonne.
The testwork was conducted using bulk material from the Mount Peake Project, and was designed to prove the full sequence of hydrometallurgical extraction of vanadium, titanium and iron products from the Mount Peake titano-magnetite orebody, as well as to provide key inputs to the final engineering design and scale-up parameters for the fabrication and construction of the TiVAN® process plant.
The testwork program and results have been fully reviewed by Mineral Engineering Technical Services (METS) and global engineering group SMS Siemag, with both groups concluding that the program has demonstrated the technical and commercial viability of the TiVAN® Process.
The patent-pending and enhanced TiVAN® Process yielded significant improvements and value-add considerations in many sections of the refinery process.
The testwork phases were conducted as follows:
- Crushing, grinding, beneficiation: to produce a magnetite concentrate; achieved with positive results.
- Feed preparation and pre-processing: this was completed with positive results with further room for optimisation identified;
- TiVAN® Leach phase: this was completed with positive results with further room for optimisation being identified particularly on scale-up;
- Solvent extraction: Solvent Extraction (SX) feed preparation and SX operation was completed using industry standard unit operations including mixer-settlers, operating conditions and circuit configuration. This section worked extremely well on a continuous basis with all recycles taken into consideration.
Conclusions and Improvements:
Considerable testwork prior to and during the pilot run allowed many significant improvements to be made to the overall process, both in design and operation. These include:
- Analytical purity of products obtainable, grading1:
Vanadium Pentoxide: > 99%
Titanium Dioxide: > 65%
Iron Oxide: > 99%
- Feed preparation improved the quality of the feed to the TiVAN® leach offering early iron removal opportunity and additional downstream advantages;
- The higher concentrate feed allowed a higher titanium grade with consequent higher recoveries with higher grade concentrate production;
- An excellent TiVAN® leaching efficiency was achieved with high extraction of vanadium into the leach solution and excellent deportment of titanium to the leach residue;
- A new SX feed preparation stage and simpler organic system achieved extraction rates for vanadium of >99% in only 1 minute whilst maintaining excellent selectivity for vanadium over iron;
- Good continuous operation of the SX circuit with excellent stripping efficiency for vanadium, minimal crud formation or lock-up of metal in the organic phase;
- The combined feed preparation, leach and SX circuits worked well together and through the piloting a number of further optimisation opportunities have arisen to provide further process efficiencies and cost savings; and
- Value added improvement have also been identified and are to be incorporated into the design.
Titanium Dioxide Pigment
The addition of refining the titanium dioxide concentrate through to pigment grade (>90% purity) represents an important improvement for the overall process. The improved recoveries and concentrate grade for Ti02 are high enough and perfectly ideal for the production of high purity titanium dioxide pigment using an industry standard chloride process.
1 Analytical purity of products is based on all test work and analytical assays conducted on TNG samples. Additional validation and optimisation work may result in grade and purity being improved further.
This provides the Company with an important high-value titanium product rather than a medium-grade product as was previously considered in the PFS. Titanium dioxide pigment is used extensively in chemical and high technology industry for a vast range of industrial and consumer goods. It currently sells for approximately US$3000/tonne, compared to the US$400/tonne used in the PFS.