NEW PHASE OF EXPLORATION UNDERWAY
- New drilling program commenced July 2018 – initial 14 hole-2000m RC and core drilling program at priority Cobalt Ridge deposit
- Strong discovery potential for multiple Cobalt Ridge ‘lookalike’ deposits within the wider Mt Gilmore Project area
- Drilling expected to be completed in the current September 2018 quarter, with results to be released as they become available
- Multiple new cobalt prospects identified within wider Mt Gilmore Project area
- Exploration results for Lantana Downs – 12 kilometres to the north of Cobalt Ridge – indicate that Cobalt Ridge is not a unique isolated cobalt deposit, but potentially part of a regionally substantive hydrothermal event
- New high-tenor gold anomaly defined at Nettle Creek – 2 kilometres south of Cobalt Ridge – is possibly related to a diorite intrusion (intrusive related gold mineralisation)
- Recent discovery of four new, large cobalt-copper-gold soil anomalies discovered north of Cobalt Ridge, immediately on strike
- Corazon produces battery-grade cobalt – highly successful completion of the initial phases of metallurgical testwork
- Testwork results to date have been exceptional and highlight Mt Gilmore’s development potential via a simple, low cost process pathway
New Phase of Drilling Underway
Corazon recently commenced its new phase of drilling at the Mt Gilmore Cobalt-Copper-Gold Project (Mt Gilmore) (Figure 1), which hosts the unique cobalt dominant sulphide Cobalt Ridge Deposit. (ASX announcement 11 June 2018). Drilling will initially focus on priority targets within and around the Cobalt Ridge Deposit, as well as test priority features generated by the Company’s recently completed 3D Induced Polarisation (IP) geophysical survey.
Drilling at Cobalt Ridge will initially include 14 holes for approximately 2,000 metres of RC and core drilling. Programs of Works approvals are currently being sought for additional drilling that will progressively drill-test new, priority target areas within the wider Project area, generated by the Company’s ongoing regional soil sampling program.
The Company expects drilling to be completed in the current September quarter and will provide details on the progress of drilling in due course; results will be released as they become available.
Figure 1. Mt Gilmore Project Location
Mt Gilmore Soil Sampling Program
Corazon is currently undertaking a geochemical soil sampling program (on a 200 metres by 200 metres pattern) of approximately 3,000 samples over a strike of more than 18 kilometres, along the trend hosting Cobalt Ridge (Figure 2). It is designed to systematically test favourable basement lithologies for cobalt, copper and gold mineralisation along strike from Cobalt Ridge.
The soil sampling program has been highly successful, to date resulting in the discovery of six high-tenor cobalt-copper-gold anomalies, within a contiguous 10 kilometre strike around Cobalt Ridge (Figure 3) (ASX announcement 4 July 2018), plus three high tenor anomalies at the Lantana Downs prospect, located 12 kilometres to the north of Cobalt Ridge (Figures 2 and 4) (ASX announcement 26 April 2018).
These anomalies provide the discovery potential for multiple Cobalt Ridge ‘lookalike’ deposits, which would significantly expand Mt Gilmore’s cobalt-copper-gold sulphide endowment.
To date, approximately 1,375 samples have been collected and the results of approximately 874 have been returned from the laboratory (including duplicate, standard and blank samples). Current work includes continuing with the regional sampling on a 200 metres by 200 metres pattern, as well as infilling anomalous areas on a 50 metres by 50 metres pattern, for the delineation of drill targets.
The results of this phase of exploration have far exceeded the Company’s expectations, already identifying several new prospects. The tenor of these cobalt anomalies are on par with the outcropping Cobalt Ridge Deposit and identify the target corridor at Mt Gilmore as having a strong multi-element correlation (that includes cobalt, copper, gold, antimony, molybdenum, tellurium, bismuth, indium and tin). It is evident that a large regional scale hydrothermal event has resulted in the cobalt sulphide mineralisation and there is expectation for the discovery of mineral deposits in addition to the Cobalt Ridge cobalt-copper-gold deposit.
The wider Mt Gilmore Project area hosts multiple historical copper-gold workings exhibiting mineralisation similar to that at Cobalt Ridge, but have yet to be tested for cobalt. These areas provide the discovery-potential for multiple Cobalt Ridge ‘lookalike’ deposits, which would significantly expand Mt Gilmore’s cobalt-copper-gold sulphide endowment.
Figure 2 –Regional geological interpretation map showing Mt Gilmore trend, soil sampling areas and cobalt-copper-gold prospect locations.
Figure 3 –Cobalt and Copper in soils images with interpreted geology and prospect locations. Exploration is targeting a window of basement rock sandwiched between granite and younger cover. (Prospects – P1 = Nettle Ck, P2 = Glamorgan, P3 = Cobalt Ridge, P4 = Morgan’s Rd, P5 = Kerry Glen, P6 = Hassan’s Ck, P7 = Gordonbrook Hill). Prospect locations also presented in Figure 2.
Figure 4 – Lantana Downs Prospect: Cobalt in soils image over aeromagnetic image
Target Generating Geophysical Surveys
During the June 2018 Quarter, a detailed 3D IP geophysical survey was completed over Cobalt Ridge, designed to map drill-defined sulphide mineralisation at depth and laterally along strike, particularly under thin cover to the east. Gap Geophysics completed the survey, making use of new technology/equipment (DIAS32) supplied by DIAS Geophysical. DIAS32 provides full 3D resistivity and induced polarisation (IP) models of the subsurface.
An aeromagnetic survey was also completed over a large area of Mt Gilmore as a first pass prospecting tool to focus in on more detailed exploration. The survey delivered high quality data highlighting distinguishable features associated with the Mt Gilmore’s current areas of known mineralisation.
This geophysical work is being used to identify high priority targets for the current and future phases of drilling.
Highly Successful Completion of Phase 3 Metallurgical Testwork
During the June Quarter, Corazon completed its highly successful Phase 3 metallurgical testwork at Mount Gilmore. The Phase 3 metallurgical testwork focused on defining down-stream concentrate processing options, and the results demonstrated exceptional recovery rates of cobalt, copper and gold from drill samples from the Cobalt Ridge Deposit, using conventional processing routes (ASX announcement 17 May 2018).
Conventional flotation testwork delivered a high-grade cobalt-copper-gold concentrate – of up to 7.38% Co – from high grade Cobalt Ridge samples, as well as excellent concentrate grades from lower low-grade samples (see Table 1);
Table 1: Met Sample and Concentrate Grades
The combination of high grade concentrates and very high recoveries delivered in the testwork provides Corazon with the opportunity to potentially either produce a high-value bulk concentrate for direct sale, or to develop an in-house down-stream processing plant.
The Company 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.
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 was identified as 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.
The testwork was managed by internationally recognised metallurgical consultants, METS Engineering and independently carried out at ALS Metallurgy in Balcatta, Western Australia.