Blackstone Minerals identifies 200m-long high-grade nickel-copper zone at Ban Chang prospect

by Leena Thomas
Image: Blackstone Minerals Limited

Blackstone Minerals Limited (ASX: BSX) announced that it has intersected massive sulfide in four maiden drill holes at Ban Chang, part of its Ta Khoa Nickel-Cu-PGE project in Vietnam.

The company said that the maiden drill hole BC20-02 at Ban Chang has delineated a 200m long zone of high-grade Nickel-Copper-PGE.

Significant high-grade results include 4.1m @ 0.92% Ni, 0.69% Cu, 0.05% Co & 0.26g/t PGE 1 from 85.9m Including 1.8m @ 2.01% Ni, 1.27% Cu, 0.12% Co & 0.53g/t PGE from 86.4m 1 Platinum (Pt) + Palladium (Pd) + Gold (Au).

Blackstone reported that its four maiden drill holes at Ban Chang have all intersected massive sulfide nickel over a 1.2km strike within a 1.2km long massive sulfide target zone defined by high priority electromagnetic (EM) plates.

The company said that assays are pending for drill hole BC20-04 which intersected 15.4m of sulfide vein mineralisation.

BSX said that a recently purchased third drill rig will follow the geophysics crew throughout the Ta Khoa nickel sulfide district, testing high priority EM targets generated from 25 MSV prospects including King Snake, Ban Khoa, Ban Chang, and Ta Cuong.

Blackstone said that drilling continues with its largest drill rig testing the King Cobra Discovery zone (KCZ) and its two smaller drill rigs at Ban Chang East and Ban Chang West.

Blackstone announced that its Scoping Study on downstream processing to produce nickel sulfate for the lithium-ion battery industry and Ban Phuc maiden resource are on track for completion in Q3, CY20.

Ta Khoa project

The Ta Khoa Nickel-Copper-PGE Project is located 160 km west of Hanoi in the Son La Province of Vietnam and includes an existing modern nickel mine built to Australian standards, which is currently under care and maintenance.

The Ban Phuc nickel mine successfully operated as a mechanised underground nickel mine from 2013 to 2016. At Ban Phuc massive sulfide vein (MSV), previous owners had successfully mined 975kt of high-grade ore at average grades of 2.4% Ni & 1.0% Cu from an average vein width of 1.3m for 3.5 years between 2013 and 2016, producing 20.7kt Ni, 10.1kt Cu, and 0.67kt Co.

Since commencing maiden drilling in August 2019, Blackstone has made significant progress at Ta Khoa, drilling over 9,000 m of diamond core in more than 47 holes into the Ban Phuc DSS deposit and the highly prospective King Cobra discovery zone.

Ban Chang prospect

The Ban Chang prospect is located 2.5km south-east of the processing facility and the Ban Phuc deposit adjacent to the Chim Van – Co Muong fault system. The prospect geology consists of a tremolitic dyke swarm within phyllites, sericite schists, and quartzites of the Devonian Ban Cai Formation. The West Zone is a 420m long zone of interpreted bifurcating MSV lenses.

Drilling at Ban Chang

The company had recently commenced drilling of four maiden drill holes at Ban Chang. Blackstone said that 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 Q3, 2020.

BSX said that the four drill holes, BC20-01, BC20-012, BC20-03, and BC20-04 were drilled more than 1.2km apart and along strike within a 1.2km-long massive sulfide target zone defined by high priority EM plates.

Hole BC20-01

Blackstone’s previously announced maiden drill hole BC20-01 had intersected high-grade results of 5.2m @ 0.66% Ni, 0.73% Cu, 0.04% Co & 0.79g/t PGE from 58.0m Incl. 1.05m @ 2.98% Ni, 1.22% Cu, 0.18% Co & 3.43g/t PGE from 58.5m.

Hole BC20-04

The drill hole BC20-04 had intersected 15.4m of sulfide vein mineralisation in June 2020.

Further high-grade results

The company reported that the latest assays from drill holes BC20-02 and BC20-03 confirm further high-grade mineralisation at Ban Chang. BSX said that assays are pending for drill hole BC20-04.

Hole BC20-02

Drill hole BC20-02 is located 200m along strike of maiden drill hole BC20-01. The company announced that BC20-02 has intersected high-grade results.

Significant hits include 4.1m @ 0.92% Ni, 0.69% Cu, 0.05% Co & 0.26g/t PGE from 85.9m or 2.3m @ 1.6% Ni, 1.09% Cu, 0.09% Co & 0.43g/t PGE from 85.9m Incl. 1.8m @ 2.01% Ni, 1.27% Cu, 0.12% Co & 0.53g/t PGE from 86.4m.

Hole BC20-03

Drill hole BC20-03 is located more than 1km along strike from Blackstone’s maiden drill hole BC20-01 at Ban Chang.

BSX announced that hole BC20-03 has delivered the high-grade result of 9.8m @ 1.45% Ni, 0.9% Cu, 0.08% Co & 0.70g/t PGE from 57.05m or 5.7m @ 2.07% Ni, 1.08% Cu, 0.12% Co & 0.95g/t PGE from 60.0m Incl. 1.85m @ 3.59% Ni, 1.18% Cu, 0.20% Co & 1.97g/t PGE from 63.35m.

Drill rigs and reduced drilling costs

BSX had recently purchased a third drill rig to follow the geophysics crew throughout the Ta Khoa nickel sulfide district, testing high priority EM targets generated from 25 MSV prospects including King Snake, Ban Khoa, Ban Chang, and Ta Cuong.

The company said that the drilling continues with Blackstone’s largest drill rig testing the King Cobra Discovery zone (KCZ) and Blackstone’s two smaller drill rigs at Ban Chang East and Ban Chang West.

Blackstone reported that with its third diamond drill rig, the Company has an all-in diamond drilling cost of US$50/m at Ta Khoa, which is a ~60% reduction in drilling costs relative to Australian industry averages.

Updates and next steps

Maiden resource: Blackstone Minerals announced that it aims to deliver a maiden resource in Q3, focused initially on the DSS at Ban Phuc, and continues to investigate the potential to restart the existing Ban Phuc concentrator through focused exploration on both MSV and DSS deposits.

Scoping study: Blackstone Minerals said that it has commenced a scoping study on the downstream processing facility at Ta Khoa. The company said that the scoping study is planned to be announced in Q3, and will provide details for joint venture partners to formalise the next stage of investment. Metallurgical testing: Blackstone Minerals said that it has commenced metallurgical testing on the Ban Phuc DSS deposit with an aim to develop a flow sheet for a product suitable for the lithium-ion battery industry. In addition, the company said that it will investigate the potential to develop downstream processing infrastructure in Vietnam to produce a downstream nickel and cobalt product to supply Asia’s growing lithium-ion battery industry.

Further work

Blackstone Minerals announced that it proposes to conduct further drilling and associated activities to better define and extend the identified mineralised zones.

Blackstone said that it plans to explore both MSV and DSS targets throughout the project, initially within a 5km radius of the existing processing facility. Blackstone Minerals reported that it will conduct further geophysics on the MSV and DSS targets and continue its maiden drilling campaign.

Management comments

Blackstone Minerals’ Managing Director Scott Williamson said: “Our latest assays confirm further high-grade mineralisation at Ban Chang. We continue to demonstrate strong potential for a bulk underground mining scenario at Ban Chang which could be significantly larger scale than the previously mined Ban Phuc massive sulfide underground mine.

At Ban Phuc, the previous owners successfully mined a 1.3m wide MSV at much lower nickel prices than today. We are seeing broader widths and significant by-products which could lend to potentially better economics than when this mine previously operated.

We have now drilled significant massive sulfide nickel mineralisation over 1.2km of strike at Ban Chang and our in-house geophysics crew continues to test for further massive sulfide mineralisation at the new target, Ta Cuong.

Ban Chang and Ta Cuong are the first of our 25 MSV targets to be tested throughout the Ta Khoa Ni-Cu-PGE district, leaving plenty of upside for adding high-grade feed to what looks like a bulk open pit mining scenario at Ban Phuc and the KCZ.”