Blackstone Minerals (ASX:BSX) continues to build its Ta Khoa project story in Vietnam with news drilling at the Ban Chang prospect has delineated a 200m-long zone containing high grades of nickel, copper and platinum group elements (PGE).
The latest hole returned 4m at 0.92% nickel, 0.69% copper, 0.05% cobalt and 0.26 grams per tonne PGE.
The first 2.3m of the intercept comprised 1.6% nickel, 1.09% copper, 0.09% cobalt and 0.43g/t PGE — and included 1.8m at 2.01% nickel, 1.27% copper, 0.12% cobalt and 0.53g/t PGE.
These results come from hole BC20-02.
Blackstone’s first four maiden drill holes at Ban Chang have all intersected massive sulphide nickel over a 1.2km strike, the zone having been identified by high priority electromagnetic (EM) plates.
Assays are pending for the fourth hole which intersected 15.4m of massive sulphide vein mineralisation (MSV).
Blackstone is targeting MSV analogous to another prospect at its Ta Khoa project, Ban Phuc, where a previous owner successfully mined 975,000 tonnes of high grade ore at average grades of 2.4% nickel and 1% copper from a vein 1.3m wide.
In all, the company has 25 MSV targets within the project area.
By-products could lead to better economics
Managing director Scott Williamson said Blackstone’s in-house geophysics crew continues to test for further massive sulphide mineralisation at another target, Ta Cuong.
“We continue to demonstrate strong potential for a bulk underground mining scenario at Ban Chang which could be significantly larger-scale that the previously mined Ban Phuc MSV mine,” he continued.
“At Ban Phuc, the previous owners successfully mined a 1.3m MSV at much lower nickel prices than today.”
Mr Williamson said the Vietnam team is seeing broader widths and significant by-products that could lead to much better economics at Ban Phuc than when it was previously mined.
The company recently purchased a third drill rig which will be used to test high priority EM targets at some other prospects, including King Snake and Ban Khoa, as well as priority targets Ban Chang and Ta Cuong.
Drilling way below Australian costs
With this third rig, Blackstone has an all-in diamond drilling cost of US$50/m (A$70/m), a 60% reduction in drilling costs compared with Australian industry averages.
Meanwhile, Blackstone’s scoping study on downstream processing to produce nickel sulphate for the lithium-ion battery industry is on track to be completed within the present quarter, as is the Ban Phuc maiden resource estimate.
Blackstone is working numerous sulphide veins and plans to develop a number of small mines (with a two to three-year mine life) to target these narrow veins.
At the Ban Phuc site, which is the only planned open pit operation, the existing infrastructure includes the 450,000tpa concentrator and a modern mechanised underground mine.
Assays are still pending from two more drill holes, one intersecting 1.2m of massive sulphide veins and the other 4.6m of massive and semi-massive sulphide veins.