Pioneer’s Golden Ridge Nickel Sulphide Project includes the Blair Nickel Mine (which ceased production in 2008). The Project is located approximately 30 km south-east of Kalgoorlie, within the Northern Kambalda District of Western Australia, and covers an area of 121 km².
The Blair Nickel Mine closed during a time of depressed nickel prices having produced 1.26mt of nickel ore at 2.62% Ni.
The Kambalda District, centred approximately 50km south of the Blair Mine, is regarded as a world class mineral field hosting numerous komatiite-hosted nickel sulphide (as well as significant gold) deposits.
The extensive number of Kambalda nickel deposits typically occur in clusters, such that the location, structure and characteristics of each nickel deposit may be used as primary vectors for the discovery of new deposits.
This documented habit of nickel deposit-clustering provides the potential for further discovery near the Blair Mine. To date the bulk of mineralization has been identified on a single, albeit dislocated, basal contact surface. Few other targets have been drilled even within 200 metres of the known Blair nickel ore shoots.
Two-Pronged Project Strategy
The Golden Ridge Project provides two nickel sulphide opportunities.
The Blair Nickel Sulphide Mine
The Blair Mine represents a leveraged nickel opportunity due to the existence of a decline to ~1000 metres depth, a fully functional haul road that provides access to the Kambalda Nickel Concentrator and is situated on a fully granted Mining Lease.
The Mineral Resource estimate is: 222,710t of nickel sulphide ore with a grade of 2.92% Ni, as summarised by category in Table 1 below:
|Class||Tonnes (t)||Ni (%)||Ni Metal (t)|
|Note: Appropriate rounding applied|
A feature of ‘Kambalda-style’ nickel sulphide deposits is their persistence with depth.
- This is evident at the Blair Mine, with mineralisation in continuous shoots from surface to 900m in depth (based on mining) with extensions indicated by drilling to at least 1,000m;
- As the geological units and the geometry of the mineralised shoots has remained consistent down-plunge, it is considered likely that this will continue below the current drilling;
- The grade of the nickel mineralisation intersected by drilling below the lowest mining levels appears to show good continuity in the down plunge orientation; and
- As with some other Kambalda mines that operate at depths below 1,000m the Company believes that mineralisation may extend well below the present Mineral Resource model.
Drilling down-plunge extensions will likely require making safe the existing mine decline and then undertaking a drilling program from towards the bottom of the decline.
Near Mine Nickel Sulphide Exploration Potential
Concurrently, the Company has been assessing targets within several kilometres of the mine infrastructure that could be accessed in a short period of time and at a relatively low cost.
The Company is advancing its work using an updated geological model for the Project, which proposed that a mafic-ultramafic dome is the dominant geological structure for the Project. This is analogous to other major nickel sulphide mining camps located to the south of the Blair Nickel Mine (which is within the Project), such as Kambalda and Widgiemooltha.
The Company uses litho-geochemical data to interpret the potential fertility of ultramafic rocks as a host for nickel sulphide mineralisation. In particular nickel, chromium, magnesium and copper can provide evidence of the correct geological environment for nickel sulphides directly and nearby. The Company will then drill the deeper targets using reverse circulation or diamond core drilling techniques directly, and for down-hole EM surveys to detect conductive geological units that might include nickel sulphides nearby.
In 2018 the Company announced that drill hole GRRC38 returned 22m at 1.02% Ni and 475ppm Cu from 202m at Leo’s Dam, which is 2.4km NE of the Blair Mine.
Cobalt is a global demand-driven commodity, with demand expanding in response to its requirement in the manufacture of cobalt-based batteries in certain electric vehicles and electricity stabilisation systems (powerwalls). Other uses for cobalt include in the manufacture of super-alloys, including jet engine turbine blades, and for corrosion resistant metal applications.
Drilling results for holes drilled between 1975 and 2008 by other explorers and 2008 to the present by Pioneer show that well developed lateritic cobalt and nickel mineralisation occurs along the eastern flank of the Blair Dome.
- The Rocket Prospect which returned the highest grade, up to 1.60% Co in GRRC37, and thickest intersection (GRRC34: 31m at 0.15% Co from 43m). Results also include an earlier diamond drill hole, BLD057: 12m at 0.27% Co from 106m, which demonstrates that mineralisation under extreme circumstances, can extend to depth.
- Leo’s Dam is sparsely drilled, and is adjacent to the ultramafic basal contact. Widely spaced drill traverses, predominantly completed by Pioneer, have returned lateritic cobalt development over a strike length of 1.5 km, and GRRC27: 22m at 0.18% Co from 38m is one of the better results from the 2017 drilling programme.
- Anomaly 13 and14 are less well defined by earlier drilling but cover over 2 km of mineralised strike length.