- Cobalt development focus in light of surging demand from tech industry
- KNP Cobalt Zone has a JORC 2012-compliant resource of 64.4 Mt at 0.13% cobalt and 0.77% nickel (28 August 2017, reported using 0.08% cobalt lower cut-off)
- Cobalt-enriched zones are contained within and are a subset of the broader KNP resource of 773.0 Mt at 0.05% cobalt and 0.70% nickel, being Australia and the developed world’s largest cobalt resource
- 4 July 2017, Thick, high-grade cobalt-nickel intersections at Goongarrie South. Assays of metallurgical diamond drill holes show expected extensive mineralisation. Pre-feasibility metallurgical testing is now underway. See full announcement for the outstanding Cobalt results.
- 13 June 2017, Cobalt at Black Range exceeds expectations; associated with scandium and accessory PGM (read more)
- 22 June 2017, Kalpini drill results highlight cobalt-nickel mineralisation, and scandium discovery (read more)
- KNP Chrysoprase (semi-precious gemstone) mechanised bulk production opportunity identified
Cobalt focus for the Kalgoorlie Nickel Project
High-grade cobalt resource
The global KNP resource of 773.0 Mt at 0.05% cobalt and 0.70% nickel contains within it high-grade concentrations of cobalt-rich mineralisation at Goongarrie South, Big Four, Scotia Dam, Aubils and Black Range (refer Ardea Prospectus pages 84-87 for global resource details). (resource updated 7 August 2017)
The KNP Cobalt Zone, a higher-grade cobalt-focused subset of the full KNP resource, was defined as 64.4 Mt at 0.13% cobalt and 0.77% nickel (reported using 0.08% cobalt lower cut-off, see Table 1 below for breakdown). This resource comprises a recalculation of cobalt resources at Goongarrie South, Big Four, Scotia Dam, Black Range and Aubils.
This new KNP Cobalt Zone resource is comprised as follows:
|Area||Prospect||Resource category||Cutoff (% Co)||Size (Mt)||Co (%)||Ni (%)|
The breakdown for the full KNP resource categories is as follows:
|Resource Category||Quantity (Mt)||Cobalt (%)||Nickel (%)||Contained cobalt (t)||Contained nickel (t)|
|KNP Total Resources||773.0||0.05||0.70||405,400||5,458,400|
Note that all values have been rounded appropriate to their deemed accuracy, so totalling values may not appear accurate.
KNP, Australia’s largest cobalt resource
Containing 386,400 tonnes of contained cobalt metal, the KNP is Australia’s largest cobalt deposit. By this measure, it is more than three times larger than Australia’s second largest cobalt deposit. The newly-reported cobalt resource from the high-grade KNP Cobalt Zone is a subset of the larger KNP resource (28 June 2017 announcement) and this subset is by itself Australia’s fourth largest cobalt resource, containing 85,410 tonnes of cobalt metal. The KNP Cobalt Zone also has one of the highest cobalt grades in Australia.
Diamond Drilling at Goongarrie South reported 4 July 2017 (announcement) was undertaken for the purpose to sample mineralisation that is representative of future mining activities. These samples will be used for the metallurgical test work that is a major part of the Pre-Feasibility Study (PFS) for the KNP Cobalt Zone. This test work will define the mechanisms for recovering cobalt and nickel from the various deposits that constitute the Cobalt Zone.
The drilling also returned as expected exceptional results to confirm high-grade cobalt and nickel mineralisation, and highlight potentially significant occurrences of scandium.
Forthcoming metallurgical studies will move the KNP towards a PFS focusing on feedstocks for the lithium ion battery industry (Lithium Nickel Manganese Cobalt Oxide - LiNiMnCoO₂ or NMC).
Highlights at Goongarrie South
- Outstanding results, including:
- AGSD0001, 131m at 0.10% cobalt and 1.06% nickel from 34m
- AGSD0002, 54m at 0.11% cobalt and 1.52% nickel from 10.0m
- AGSD0004, 39m at 0.20% cobalt and 1.35% nickel from 18.7m
- Several high-grade zones within these thick intercepts, including:
- AGSD0001, 7.2 m at 0.92% cobalt and 2.19% nickel from 95.6m
- AGSD0004, 28 m at 0.27% cobalt and 1.57% nickel from 22m
- Uniform mineral composition over entire thick mineable intercepts.
- Consistency of results and goethite-dominant mineralisation provide for high-quality and stable plant feed for a future mining operation.
- Pre-Feasibility Study hydro-metallurgical leach tests commence this week.
Highlights at Black Range
- Extensive blanket of strong cobalt and nickel mineralisation intercepted at Black Range.
- Scandium discovered at Black Range as a significant surface enrichment, with accessory platinum and palladium being widely distributed. Together, these metals form a continuous sheet of mineralisation commonly from surface.
- Cobalt-nickel intercepts include:
- ABR0006, 10 m at 0.12% Co and 0.74% Ni from 16.0 m
- ABR0008, 16 m at 0.16% Co and 0.74% Ni from 60.0 m
- ABR0009, 10 m at 0.12% Co and 0.81% Ni from 34.0 m
- ABR0013, 10 m at 0.21% Co and 0.75% Ni from 4.0 m
- ABR0014, 8 m at 0.20% Co and 0.87% Ni from 2.0 m
- Other metals contained in the laterite show potential for added credits during open pit cobalt and nickel mining.
- Scandium (45 – 170 g/t)
- Platinum and palladium (0.5 – 1.29 g/t)
- Chromium (0.5 – 2.95%)
- Ability to provide payable credits, notably scandium, will be determined during the KNP Cobalt Zone Pre-Feasibility Study
- Black Range resource interim update - 28 August 2017: The new Total Mineral Resource for Black Range is 19.2 Mt at 0.09 % cobalt and 0.68 % nickel (utilising a 0.5 % nickel cut-off).
Scotia Dam cobalt-nickel deposit
The Scotia Dam resource is a small, high-grade cobalt-nickel deposit at the southern end of the Goongarrie camp of deposits. Cobalt mineralisation at Scotia Dam is continuous over around 1,200 metres of strike using a 0.05 % cobalt grade shell.
The remodelled Total Resource for Big Four is 2.5 Mt at 0.17% cobalt and 0.82% nickel (announcement dated 28 August 2017).
Historically, cobalt and nickel mineralisation at Kalpini has been identified over an approximate 30 km strike length. Thick intercepts of mineralisation are evident at numerous localities and these have contributed to the historic Inferred Mineral Resource at Kalpini of 75.0 Mt at 0.044% cobalt and 0.73% nickel. (see the Ardea Resources Prospectus p.86 for further details).
In the June 2017 quarter, Ardea completed a drill program aimed to infill and characterise some of the lesser drilled areas between the defined deposits at Kalpini. Ardea’s recent drilling was purposefully targeted at gaps in the distribution of historic drilling (Figure 2). Results (Figure 3, Figure 4) show that higher cobalt and nickel values are consistent with historic results. Intercepts at a 0.5% nickel cut-off grade include the following:
- AKR0005, 24 m at 0.05% cobalt and 0.83% nickel from 16.0 m
- AKR0010, 8 m at 0.14% cobalt and 0.66% nickel from 0.0 m
- AKR0016, 26 m at 0.12% cobalt and 0.90% nickel from 18.0 m
including 8 m at 0.30% cobalt and 1.65% nickel from 28.0 m
- AKR0022, 24 m at 0.04% cobalt and 0.74% nickel from 20.0 m
- AKR0027, 36 m at 0.05% cobalt and 0.93% nickel from 20.0 m
Distributions of scandium, which has not been previously explored for at Kalpini, differ locally to the nickel and cobalt distributions (Figure 3, Figure 4). The discovery of thick scandium intercepts at Kalpini is significant because they could become a potentially meaningful by-product credit. Scandium intercepts include:
- AKR0006, 6 m at 60 g/t scandium from 12.0 m
- AKR0015, 20 m at 102 g/t scandium from 38.0 m
- AKR0017, 6 m at 463 g/t scandium from 28.0 m
- AKR0018, 20 m at 105 g/t scandium from 2.0 m
- AKR0021, 10 m at 46 g/t scandium from 18.0 m
- AKR0028, 8 m at 57.5 g/t scandium from surface
Assessment of the Kalpini system of deposits is ongoing.
Semi-precious gemstones within the KNP – Chrysoprase (“Australian Jade”)
The Kalgoorlie Nickel Project is characterised by widespread occurrences of the semi-precious gemstone chrysoprase. Chrysoprase is a rare, highly valued, nickel-bearing variety of chalcedony. Colour varies from apple green to deep green, and the highest quality material is translucent. Chrysoprase is commonly known by gemologists as “Australian jade” and is often used in jewellery as a substitute for jade due to its harder wearing characteristics. Chrysoprase is highly valued in east Asia notably China.
The occurrence of chrysoprase in shallow strongly weathered horizons throughout the KNP is directly analogous to the occurrence of opal in the opal fields of Coober Pedy (SA) and Lightning Ridge (NSW). As in the opal fields, chrysoprase has developed in veins within cracks and crevices in the clay-rich host rocks. In the KNP, the highest quality, deepest green chrysoprase shows a direct spatial relationship to the cobalt- and nickel-rich parts of the orebodies. Ardea has defined five advanced stage chrysoprase pit opportunities within the KNP.
Ardea estimates open-pit mining costs of approximately $6/t with run-of-mine chrysoprase valued at approximately $8-20/kg, and gem quality in excess of $20/kg (break-even grade 1kg/t of lower quality chrysoprase). Kalgoorlie chrysoprase mining has traditionally been labour-intensive and conducted by small scale tributers. Ardea has scoped a mechanised production model using ore sorting technology.
Ardea believes an east Asia jewellery producer would be a preferred chrysoprase development partner.