Multiple stage grinding LIMS testwork completed on larger scale fresh massive magnetite composite samples.
High grade magnetic concentrate of up to 67.1%1 Fe in MASFR1 and 64.1% Fe in MASFR2 with mass yields of 59.5% and 66.2% respectively1 at 32 micron grind size.
Confirmation of ability to produce a premium Platts 65 product with very low levels of deleterious elements.
Contained high grade vanadium of 1.74% V2O5 (MASFR1) and 1.61% V2O5 1 (MASFR2).
Opportunity to produce high quality product at coarser grind size supported by grades of up to 64.3% Fe in MASFR1 and 62.6% Fe in MASFR2 at 125 micron grind size.
Titanium separation testwork underway on non magnetic tailings stream generated from LIMS work.
Technology Metals Australia Limited (ASX: TMT) (“Technology Metals” or the “Company”) is pleased to announce the results of magnetic concentrate testwork based on staged grinding of two large sample masses of fresh massive magnetite composites from the Yarrabubba Iron-Vanadium Project (“Yarrabubba Project”).
The two and three stage grinding magnetic separation testwork (LIMS) has exceeded the results of the previous sighter testwork and confirmed the opportunity to produce a high grade, high purity iron-vanadium concentrate (“Yarrabubba High Grade IronVanadium Product”) of up to 67.1% Fe at a 32 micron grind size and up to 64.3% Fe at a 125 micron grind size.
Managing Director Ian Prentice commented: “This testwork has provided further confirmation of the opportunity to produce a high grade, high purity Fe-V magnetic concentrate at Yarrabubba as the testwork programs scale up. Importantly the work has also provided sufficient sample to progress diagnostic titanium recovery testwork, which the team is actively progressing as we embark on a very exciting and transformative 2021. The range of products anticipated to be generated from Yarrabubba is a very exciting component of the Project and is expected to be very well received by customers and funding partners.”
The Yarrabubba Iron-Vanadium Project, located on granted Mining Lease M51/884, hosts an Indicated and Inferred Mineral Resource estimate (“MRE”) of 27.7Mt at 38.7% Fe and 0.9% V2O5 including a high grade massive mineralisation zone of 14.4Mt at 48.1% Fe and 1.1% V2O5. CSA Global previously prepared a Maiden Probable Ore Reserve estimate for M51/884 of 9.4Mt at 45.3% Fe and 0.97% V2O5, which includes a large proportion of the high grade massive magnetite unit. The Ore Reserve consists of only fresh mineralisation, with fresh ore at Yarrabubba commencing from 10 to 15m below surface. The presence of higher yielding fresh ore close to surface has very positive implications for operating costs.
A program of sighter metallurgical testwork, consisting of Low Intensity Magnetic Separation (“LIMS”) on seven (7) representative composite samples formed from PQ diamond drill hole material (see Figure 1 for drill hole locations), delivered outstanding high grade, high purity iron-vanadium concentrate results across all of the mineralised units at Yarrabubba. A weighted average grade of 64.3% Fe, 1.71% V2O5, 6.34% TiO2, 0.42% SiO2 and 0.67% Al2O3 and an overall mass recovery of 47.6% was recorded at a 32 micron grind size. At a coarser grind size of 75 micron the weighted average grade of product was 62.8% Fe, 1.66% V2O5, 7.83% TiO2, 0.62% SiO2 and 0.96% Al2O3 with an overall
mass recovery of 49.6% (ASX Announcement 11 November 2020). The full set of LIMS testwork confirmed the very high rejection of deleterious elements across all of the composites at the 32 micron grind size, with weighted average grades of 0.42% SiO2, 0.67% Al2O3, 0.011% S and 0.001% P.
A further round of laboratory scale LIMS testwork has now been completed on larger sample masses of the fresh massive magnetite composites (see Figure 2 for location and distribution of the Massive Magnetite Unit); 300kg of MASFR1 and 90kg of MASFR2. This testwork was designed to confirm the outcomes of the sighter testwork under both three stage (500 micron, 125 micron and 32 micron) and two stage (125 micron and 32 micron) grind scenarios and generate sufficient volume of nonmagnetic tailings to further investigate the titanium separation circuit.
The testwork involved grinding the composite to the requisite size (500 micron for the three stage grind, 125 micron for the two stage grind) (“Primary Grind”) prior to passing the sample through triple pass LIMS at 1200 Gauss. The magnetic component from the Primary Grind was then dried, homogenised and milled down to the next grind size (125 micron for the three stage grind, 32 micron for the two stage grind) (“Secondary Grind”), with the sample again passed through triple pass LIMS at 1200 Gauss. For the three stage grind the magnetic component from the Secondary Grind was dried, homogenised and milled down to the final 32 micron grind size. The non-magnetic components from each cycle (grind size) were collected for further investigation of the titanium separation from thenon-magnetic tailings
Results of the magnetic separation phase of the testwork program have strongly confirmed the outcomes of the previously announced sighter testwork, delivering up to 67.1% Fe and 1.74% V2O5 at a 32 micron grind size for MASFR1 and 64.1% Fe and 1.61% V2O5 at a 32 micron grind size for MASFR2 at very high mass recoveries of approximately 60 to 66% . The magnetic concentrate grades are typically slightly higher from the larger scale testwork relative to the sighter testwork, with greater rejection of impurities . The very high recoveries of both iron and vanadium into a magnetic concentrate for the massive fresh composites were also confirmed, with iron recoveries ranging from 76 to 90% and vanadium recoveries ranging from 85.0 to 93%.
Importantly at a coarser grind size of 125 micron, MASFR1 delivered a product containing up to 64.3% Fe and 1.65% V2O5 and MASFR2 delivered a product containing up to 62.6% Fe and 1.56% V2O5 at mass recoveries of 65.4% and 71.3% respectively. This work indicates an opportunity to operate at an
intermediate grind size to generate a high grade, high purity iron-vanadium concentrate whilst maintaining a high level of rejection of titanium to the non-magnetic tail component.
The larger scale LIMS testwork has again confirmed the very high rejection of deleterious elements from the Massive Magnetite ore, with contained values of less than 0.3% SiO2 at the 125 micron grind size down to less than 0.1% at the 32 micron grind size and less than 1.6% Al2O3at the 125 micron grind size down to less than 1.0% at the 32 micron grind size.
This work has once again demonstrated the scope for the Yarrabubba High Grade Iron-Vanadium Product to meet the premium Platts 65 product specifications, with very high iron grades combined with very low levels of impurities.
Titanium Separation Testwork
The original program of sighter metallurgical testwork identified clear potential to discriminate between vanadiferous iron (V+Fe) phases and titanium (TiO2) containing phases, resulting in TiO2 rejection to the non-magnetic tails stream. Initial and unoptimised sighter testwork to assess the ability to recover the titanium from the non-magnetic tails stream generated products with grades up to 48.5% TiO2 for MASFR1 and 48.4% TiO2 for MASFR2 utilising standard gravity separation techniques.
Non-magnetic tails from the larger scale LIMS testwork program have been collected from each cycle (grind size) and are being utilised for further investigation and optimisation of the potential to generate a high grade titanium product from this tails stream using standard gravity separation techniques. This work is underway, with the outcomes of the testwork expected to provide further guidance on an appropriate flowsheet for the titanium separation, enhance the quality of the titanium product as well as provide guidance on the expected product yields.
 For more details, please visit the website:https://www.australianvanadium.com.au/