Mt Gilmore, NSW

Mt Gilmore Copper-Cobalt-Gold Project, NSW – Australia

Recent news: Drilling commences at Mt Gilmore NSW


The Mt Gilmore Copper-Cobalt-Gold Project is located 35 kilometres from the city of Grafton in north-eastern New South Wales (Figure 1). Corazon owns an 80% interest in Mt Gilmore and is managing and sole funding exploration until any future decision to mine is made.

Much of Mt Gilmore’s historical exploration has focused on the Cobalt Ridge prospect (Cobalt Ridge) – a rare high-grade cobalt sulphide deposit. Corazon’s metallurgical test-work on the Cobalt Ridge mineralisation has delivered exceptional, high-grade metal concentrates and cobalt/copper sulphates, suitable for use in rechargeable (lithium- ion) batteries.

Since acquisition in mid-2016, Corazon’s exploration results have underpinned its belief that Mt Gilmore
is prospective for hosting multiple rare, cobalt-rich sulphide deposits, similar to Cobalt Ridge. Corazon’s recent exploration of the prospective 22 kilometre “Mt Gilmore trend” uncovered a major copper- cobalt-silver-gold geochemical trend, potentially representing a district-scale exploration play for large intrusive-related copper-cobalt-gold deposits, providing Corazon with a unique early-stage copper- driven opportunity. These targets are Corazon’s exploration focus at Mt Gilmore.

Figure 1: Mt Gilmore - Project location map

Figure 1: Mt Gilmore Project location map


Corazon’s latest phase of exploration at Mt Gilmore confirmed the project’s porphyry potential (ASX announcement 9 October 2020).

The identification of a copper-bearing diorite porphyry intrusion at the Gordonbrook Hill Prospect (Gordonbrook Hill) has significantly advanced Mt Gilmore’s prospectivity.

This intrusion is located coincidently on the margins of a high-grade copper and gold
soil geochemical anomaly, and the surface projection of a concealed, high-value, Induced Polarisation (IP) geophysical anomaly.

These coincident geochemical and geophysical anomalies at Gordonbrook Hill represent a significant mineralised porphyry target, which is now the priority target at Mt Gilmore.

All permits for drilling this target have been received, and drilling is currently underway.


Corazon’s exploration work has uncovered multiple, large (>1 kilometre) priority targets within a major copper-cobalt-silver-gold feature of more than 11 kilometres in strike length, which forms part of the currently defined 22 kilometre- long, mineralised Mt Gilmore Trend.

Initial field reconnaissance of the anomalous copper-cobalt-sliver trend at Mt Gilmore
has identified several areas of hydrothermal alteration and disseminated sulphide mineralisation at surface. Sulphides observed include extensive disseminated pyrite, pyrrhotite and chalcopyrite (copper sulphide) – consistent with the geochemical anomalism identified by Corazon’s soil sampling program.

This exploration work has proven to be highly effective in mapping alteration and mineralisation at Mt Gilmore, and provides compelling evidence of an extensive hydrothermal event with metal associations indicative of large intrusive related copper-gold systems.

Importantly, these newly identified areas of mineralisation are distal to the high-grade copper rich structures previously identified by Corazon (ASX announcement 5 February 2019), and are believed to test a mineralised alteration halo of what may potentially be a large, concealed sulphide system.

Mt Gilmore Project - interpreted regional geology over copper in soils
Figure 2: Mt Gilmore Project interpreted regional geology over copper in soils

Recent structural interpretation of the Mt Gilmore Trend has assisted with the determination of areas planned to be subjected to Induced Polarisation (IP) geophysical surveys (Figure 2), which are typically useful in identifying sulphide mineralisation at depth.

Corazon’s assessment that the numerous occurrences of copper-cobalt-gold mineralisation identified in late-1800’s/early-1900’s small scale mining operations may in fact be part of a much larger system, represents a significant advancement for Mt Gilmore, substantially increasing its potential.

The new, high-tenor cobalt-copper-silver-gold soil sample anomalies are supported by high- grade rock chip samples (ASX announcement 22nd November 2018). Better results include up to 21.6% copper, 1,795ppm cobalt, 1.29g/t gold, 361ppm silver and 885ppm molybdenum. The structures hosting this mineralisation are interpreted to be “leakage-structures” from a concealed copper sulphide system.

This geochemical trend represents a district- scale exploration play for large intrusive-related copper-cobalt-gold deposits and provides Corazon with a unique early-stage copper- driven opportunity.


Corazon’s 2018 21-hole, 2,967.65 metre drilling program focused on the Main Lode at Cobalt Ridge, and returned numerous +1% cobalt assays, with the best result being 5 metres @ 2.14% cobalt (ASX announcement 9th November 2018).

The results from this program provided Corazon with a strong understanding of the controls on the mineralisation. This data has been worked back into geological models for the Cobalt Ridge Main Lode and is also being used to identify priority drill target areas.

Cobalt Ridge remains substantially under-drilled and there is demonstrated potential to define additional areas of mineralisation. The Cobalt Ridge Main Lode remains open in all directions and is only one of numerous parallel mineralised trends, defined by historical workings and broad- spaced drilling, that have yet to be targeted with resource definition drilling.


Corazon has completed several phases of metallurgical testwork on the drill samples from the Main Lode at Cobalt Ridge.

The combination of high grade concentrates and very high recoveries delivered by Phase
3 testwork has provided the opportunity
to potentially produce a high-value bulk concentrate for direct sale, or to develop an in- house down-stream processing plant.

Corazon has produced high-grade concentrates from simple flotation processing, with solvent extraction following standard pressure oxidation (POX), to deliver separate high-quality cobalt and copper sulphates. Gold is captured separately from the POX residue.

Table 1: Phase 3 metallurgical sample and concentrate grade
Table 1: Phase 3 metallurgical sample and concentrate grade

The mineralisation at Cobalt Ridge has several beneficial characteristics. A key advantage for the processing is the sulphide mineralisation at Cobalt Ridge, which allows for a smaller sulphide/metal concentrate to be produced prior to down-stream processing. This would likely significantly reduce the capital and operating costs of a down-stream plant, compared to having to process a bulk feed.

Down-stream testwork focused on the use of POX as the method for cobalt and copper extraction. POX is the preferred process route due to its potentially lower cost, processing adaptability for variable mineralisation, and its capacity to deliver environmentally stable and controlled waste products.

The POX testwork achieved excellent results, with up to 98.91% cobalt and 96.70% copper extraction. The solution from the POX underwent precipitation testing in order to assess metal removal, with solvent extraction testing being completed using conventional organics.

All testwork has been managed by internationally recognised metallurgical consultants, METS Engineering and independently carried out at ALS Metallurgy in Balcatta, Western Australia.