Blackstone Minerals announces new Viper discovery zone at Ban Chang

by Leena Thomas
Image: Blackstone Minerals Limited

Blackstone Minerals Limited (ASX: BSX) has announced the discovery of a new zone of nickel mineralisation coincident with high priority EM plates at the Viper Discovery Zone (VDZ), east of Ban Chang, within its Ta Khoa Nickel-Cu-PGE project in Vietnam.

Blackstone said that its in-house geophysics crew recently generated the blind discovery of potential massive sulfide nickel targets at VDZ with a series of new shallow EM anomalies located ~200m north-east of Ban Chang East.

BSX said that its geology team followed up the new EM anomalies with a series of trenches to better understand the prospectivity of the VDZ. The company said that trench BCH20-03 located directly above a new EM anomaly at VDZ discovered a nickel-copper gossan (iron cap formed by the oxidation of sulfides) with a float sample assaying 0.8% Ni & 0.5% Cu (determined by Niton portable XRF).

Blackstone said that VDZ is a blind discovery with no surface exposures of nickel sulfide or ultramafic. The company reported that this bodes well for further blind discoveries of massive sulfide nickel using Blackstone’s in-house geophysics crews to unlock the extensive potential throughout the Ta Khoa Nickel-Cu-PGE district.

It may be noted that Blackstone’s four maiden drill holes at nearby Ban Chang had all intersected massive sulfide nickel over a 1.2km strike within a 1.2km long massive sulfide target zone defined by high priority EM plates.

Blackstone announced that its Maiden Resource Estimate and Scoping Study on downstream processing to produce nickel sulfate for the lithium ion battery industry are also on track for release this quarter.

Ta Khoa project

The Ta Khoa Nickel-Copper-PGE Project is located 160 km west of Hanoi in the Son La Province of Vietnam.

The Ta Khoa project includes an existing modern nickel mine which has been under care and maintenance since 2016 due to falling nickel prices. Existing infrastructure includes an internationally designed 450ktpa processing plant. Previous project owners focused mining and exploration efforts primarily on the MSV at Ban Phuc.

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.

High-grade previous results from Ban Chang

The company had previously announced high-grade results from the maiden Ban Chang drill holes BC20-01, BC20-02, BC20-03, and BC20-04.

Highlights included BC20-01: 5.2m @ 0.66% Ni, 0.73% Cu, 0.04% Co & 0.79g/t PGE from 58.0m or 1.5m @ 2.20% Ni, 2.12% Cu, 0.13% Co & 2.66g/t PGE from 58.5m incl. 1.05m @ 2.98% Ni, 1.22% Cu, 0.18% Co & 3.43g/t PGE from 58.5m; BC20-02: 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; BC20-03: 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; and BC20-04 21.5m @ 0.69% Ni, 0.66% Cu, 0.03% Co & 0.81g/t PGE from 71m or 13.4m @ 1.01% Ni, 0.96% Cu, 0.05% Co & 1.14g/t PGE from 76m incl. 2.1m @ 2.53% Ni, 1.36% Cu, 0.11% Co & 0.76g/t PGE from 77.6m.

New Viper Discovery Zone (VDZ)

The company said that it has discovered a new zone of nickel mineralisation coincident with high priority electromagnetic (EM) plates called the Viper Discovery Zone (VDZ), east of Ban Chang. The Viper Zone is located within the Ta Khoa Concession and is covered by the Foreign Investment Licence, 522 G/P.

The Viper Discovery happened soon after the Company recently moved to an aggressive drill-out phase to delineate a maiden resource at Ban Chang to supplement the ongoing studies focused on producing nickel sulfate for the lithium-ion battery industry.

Blackstone reported that its in-house geophysics crew recently generated the blind discovery of potential massive sulfide nickel targets at VDZ with a series of new shallow EM anomalies located ~200m north-east of Ban Chang East.

Blackstone’s geology team followed up the new EM anomalies with a series of trenches to better understand the prospectivity of the VDZ and discovered a nickel-copper gossan with a float sample assaying 0.8% Ni & 0.5% Cu (determined by Niton portable XRF).

Blind discovery

The company said that the VDZ is a blind discovery located east of the Ban Chang prospect, with no surface exposures of nickel sulfide or ultramafic. BSX said that this bodes well for further blind discoveries of massive sulfide nickel using Blackstone’s in-house geophysics crews to unlock the extensive potential throughout the Ta Khoa Nickel-Cu-PGE district.

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. The company said that it continues to investigate the potential to restart the existing Ban Phuc concentrator through focused exploration on both MSV and DSS deposits.

Scoping study: Blackstone said that it has commenced a scoping study on the downstream processing facility at Ta Khoa. The scoping study is planned to be announced in Q3 and is expected to provide details for joint venture partners to formalise the next stage of investment.

Metallurgical testing: Blackstone reported 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. The Company said that it plans to downstream nickel and cobalt product to supply Asia’s growing lithium-ion battery industry.

MSV and DSS targets: Blackstone announced that it plans to explore both MSV and DSS targets throughout the Ta Khoa Nickel-PGE Project in northern Vietnam, initially within a 5km radius of the existing processing facility. Blackstone said that it will conduct further geophysics on the MSV and DSS targets and continue its maiden drilling campaign.

Drilling ongoing: Blackstone announced that it is continuing its aggressive exploration program with six drill rigs, four owned by the Company. Three rigs are drilling at Ban Chang, testing massive sulfide vein (MSV) targets and three are testing down dip extensions of the King Cobra Discovery Zone (KCZ) at Ban Phuc.

Management comments

Blackstone Minerals’ Managing Director Scott Williamson said: “We’re excited to announce the new Viper Discovery Zone at Ban Chang, a massive sulfide target initially generated by our in-house geophysics team and recently followed up by our geology team to confirm the potential of the target to host nickel-copper sulfide mineralisation.

The VDZ is a blind discovery which bodes well for further blind discoveries throughout the Ta Khoa Nickel-Cu-PGE district and shows the potential of this project to host much more undiscovered nickel sulfide mineralisation.

In addition to blind discovery potential, we have 25 massive sulfide targets, which are all associated with outcropping mineralisation at surface, and with our in-house geophysics team, we can generate additional blind discoveries that were not known to previous operators of the project.”