Blackstone Minerals yields ‘excellent’ PGE recoveries during test work on Ta Khoa ore
Blackstone Minerals’ latest hole from Ban Chang unearthed up to 2.01% nickel, 1.27% copper, 0.12% cobalt and 0.53g/t PGE.
Test work on ore from Blackstone Minerals’ (ASX: BSX) flagship Ta Khoa project in northern Vietnam has yielded “excellent recoveries” of palladium, platinum and rhodium.
The test work was part of Blackstone’s downstream processing pre-feasibility study, which is evaluating the company’s strategy of developing precursor battery materials for the South East Asian market.
Simulus Engineers undertook the testing on pressure oxidation residues and demonstrated “excellent recoveries” of platinum group elements (PGE) including palladium, platinum and rhodium.
These recoveries were generated using a conventional flow sheet.
After a 360-minute leach time, using a 3.32 grams per tonne palladium head grade, a 94% recovery was achieved.
In the same time-frame, a 2.38g/t platinum concentrate had an 80% recovery and 0.33g/t rhodium yielded an 81% recovery.
Further testing is ongoing to optimise the result while studies are underway that aim to incorporate a PGE recovery circuit in the downstream pre-feasibility study.
Blackstone managing director Scott Williamson said the recovery of PGEs will add more value to the company’s proposed downstream refinery business.
“Palladium, platinum and rhodium could offer significant by-product credits, thereby reducing the overall cost of producing nickel, cobalt, manganese precursor products.”
“Blackstone offers a unique opportunity for investors to gain exposure to PGEs on the Australian Stock Exchange.”
Mr Williamson noted palladium, platinum and rhodium will play an important part in addressing climate change due to their role in reducing emissions from vehicles.
“In addition, we expect growing demand for platinum given its use as a catalyst in hydrogen fuel cell technology,” he added.
Drill results
Drilling at Ta Khoa is underway with previous work from 2019 unearthing significant PGE intercepts at the Ban Phuc disseminated sulphide (DSS) deposit.
Highlight PGE intercepts at Ban Phuc comprised: 11.95m at 0.65g/t palladium, 0.47g/t platinum and 0.06g/t rhodium from 107m, including 2m at 0.9g/t palladium, 0.79g/t platinum, and 0.09g/t rhodium from 110m; 1m at 2.14g/t palladium, 1.89g/t platinum and 0.13g/t rhodium from 109.6m; and 5.1m at 0.82g/t palladium, 0.61g/t platinum and 0.08g/t rhodium from 188.3m.
As well as evaluating PGE recoveries in DSS mineralisation, Blackstone will assess the potential using massive sulphide vein (MSV) mineralisation such as that found at Ban Chang and King Snake.
At these MSV deposits, drilling returned notable PGE intersections of 1.05m at 2.04g/t palladium, 0.6g/t platinum, and 0.09g/t rhodium from 58.50m; 1m at 2.33g/t palladium, 0.15g/t platinum and 0.15g/t rhodium from 63.35m; and 0.3m at 0.95% nickel, 2.73% copper, 0.17% cobalt and 15.99g/t PGE from 72.12m.