Blackstone Minerals Ltd (ASX:BSX) (FRA:B9S) has extended the strike at Ban Chang prospect of its Ta Khoa project in Vietnam by more than 1-kilometre after hitting up to 5.7 metres at 2% nickel, 1% copper, 0.12% cobalt and 1 g/t PGE.
Step-out reconnaissance-style drilling has intersected high-grade mineralisation in hole BC20-03, which is more than 1-kilometres along strike from Blackstone’s maiden Ban Chang hole that delivered 5.2 metres at 0.66% nickel, 0.73% copper, 0.04% cobalt and 0.79 g/t PGE from 58 metres.
This means that the four maiden Ban Chang holes have all intersected massive sulphide nickel over a 1.2-kilometre strike within a massive sulphide target zone defined by high priority electromagnetic (EM) plates.
Shares at 2-year high
The results have prompted a strong investor response with shares as much as 17% higher to 24 cents, a new two-year high.
Blackstone Minerals’ managing director Scott Williamson said the latest assays confirmed a new zone of high-grade mineralisation which was previously untested.
Bulk mining potential
He said: "We have demonstrated strong potential for a bulk underground mining scenario at Ban Chang which could be significantly larger scale than the previously mined Ban Phuc massive sulphide underground mine.”
Within the 5.7-metre intersection from 60 metres in BC20-03 was 1.85 metres at 3.59% nickel, 1.18% copper, 0.20% cobalt and 1.97 g/t PGE from 63.35 metres with both intercepts within a 9.8-metre intersection from 57.05 metres at 1.45% nickel, 0.9% copper, 0.08% cobalt and 0.70 g/t PGE.
Assays are still pending for drill holes BC 20-02 which intersected 1.2 metres of massive sulphide veins (MSV) and BC 20-04 which intersected 15.4 metres of sulphide vein mineralisation.
Targeting regional MSV
The drilling is part of an ongoing campaign to target regional MSV as Blackstone aims to build its resource inventory at Ta Khoa to supplement the Ban Phuc maiden resource, which is on track for completion in the current quarter.
Blackstone continues to test high priority EM targets generated from 25 MSV prospects in the Ta Khoa nickel sulphide district to supplement a potential bulk open pit mining scenario at Ban Phuc and the King Cobra discovery zone (KCZ).
“Very economic mining scenario”
Williamson said: “At Ban Phuc, the previous owners successfully mined a narrow massive sulphide vein at much lower nickel prices than today.
“With bulk underground mining and the potential for significant PGE credits, we could be looking at a very economic mining scenario at Ban Chang.
“We have now drilled significant massive sulphide nickel mineralisation over 1-kilometre of strike at Ban Chang and our in-house geophysics crew continues to test for further massive sulphide mineralisation.
“Ban Chang is the first of 25 MSV targets to be tested throughout the Ta Khoa Ni-Cu-PGE district, leaving plenty of upside for adding high-grade feed to a bulk open pit mining scenario at Ban Phuc.”
Blackstone is targeting MSV prospects analogous to Ban Phuc MSV, where previous owners mined 975,000 tonnes of high-grade ore at average grades of 2.4% nickel and 1.0% copper from an average vein width of 1.3 metres, producing 20,700 tonnes of nickel, 10,100 tonnes of copper and 670 tonnes of cobalt.
Scoping study on track
A scoping study on downstream processing to produce nickel sulphate for the lithium-ion battery industry and a Ban Phuc maiden resource are on track for completion this quarter.
The downstream processing potential is supported by $6.8 million investment from EcoPro Co Limited, the world’s second-largest nickel-rich cathode materials manufacturer, completed in April 2020.