Drilling at Blackstone Minerals’ (ASX: BSX) Ban Chang prospect has uncovered yet more high-grade nickel and copper mineralisation and extended the known strike, firming up the potential for a viable bulk mining operation.
All four maiden holes at Ban Chang have uncovered massive sulphide nickel over 1.2km of strike.
Latest assays have returned 9.8m at 1.45% nickel, 0.9% copper, 0.08% cobalt and 0.70 grams per tonne platinum group elements from 57.05m.
Within the 9.8m intercept was 5.7m at 2.07% nickel, 1.08% copper, 0.12% cobalt and 0.95g/t PGE; and 1.85m at 3.59% nickel, 1.18% copper, 0.20% cobalt and 1.97g/t PGE.
This hole was drilled more than 1km along strike of the maiden hole at the prospect which delivered 5.2m at 0.66% nickel, 0.73% copper, 0.04% cobalt and 0.79g/t PGE from 58m, including 1.05m at 2.98% nickel, 1.22% copper, 0.18% cobalt and 3.43g/t PGE.
Blackstone managing director Scott Williamson said the latest assays confirm the existence of the mineralised zone and shore up the potential of a bulk underground mining scenario at the prospect.
He noted Ban Chang could be “significantly” larger than the previously mined prospect Ban Phuc within the wider Ta Khoa project.
“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,” Mr Williamson said.
He added that Ban Chang was the first of 25 targets to be tested throughout Ta Khoa – offering plenty of upside for generating high-grade feed to a bulk operation at Ban Chang.
Assays are pending for two drill holes at Ban Chang which hit 1.2m of massive sulphide veins and 15.4m of sulphide vein mineralisation respectively.
Ta Khoa nickel-copper project
Located in northern Vietnam, Ta Khoa hosts numerous targets and includes the former Ban Phuc mine which generated 20,700t of nickel and 10,100t copper at average grades of 2.4% nickel and 1% copper. A further 670t of cobalt was also produced.
The mine operated between 2013 and 2016 and the project also has a 450,000tpa processing facility, which has been on care and maintenance.
Blackstone is focused on investigating targets within trucking distance of the plant.
Additionally, the company has scoping study underway evaluating the potential of downstream processing to produce nickel sulphate for lithium-ion batteries.
This is due to be completed in the September quarter along with a maiden resource for Ban Phuc.