THE CONFERENCE CALLER: A busy six months with the drill rig hass merely confirmed what Centaurus Metals (ASX: CTM) has suspected for a while – that its evolving near-surface Jaguar nickel sulphide play in Brazil is a winner. By Mark Fraser
The company is currently in the process of completing two scoping studies for the project and is now hoping to make a decision-to-mine by 2023, with a 20,000 tonne-plus per annum nickel operation pencilled in to start by the end of the following year.
During the fortnight leading up to its appearance at the opening day of the RIU Explorers Conference in Western Australia, the WA-based junior announced it had significantly increased the indicated component of Jaguar’s Global Mineral Resource Estimate (GMRE) by over 50% to 223,400 contained tonnes of the base metal, a development which augurs well for the company’s first base case scoping document due next month.
The project – which is located in northern Brazil’s Carajas mineral province – now has a total GMRE of 58.6 million tonnes of ore grading 0.95 per cent nickel for 557,800 tonnes of contained nickel.
Importantly, the indicated component of this currently sits at 19.9 million tonnes at 1.12 per cent nickel for the aforementioned 223,400 tonnes, representing 40 per cent of the deposit’s GMRE, thanks to the junior’s in-fill diamond drilling campaign conducted over the past half year.
Significantly, the grade of this indicated material is almost 20% higher than the GMRE’s grade, demonstrating the project’s ability for early payback.
Furthermore, as more than 80% of the contained nickel in the global estimate sits within 200 metres from surface, all indications are that a large open pit will initially be established.
The February 2021 GMRE update is based on more than 74,500m of diamond drilling across 267 holes. This included an additional 49 diamond holes, for 8,150m, of predominantly infill drilling that was conducted since the company’s maiden JORC-compliant maiden global estimate was released in June last year.
The primary focus of this infill activity was to convert inferred resources to the indicated category within potential open pit limits.
This involved drilling on a 50 by 50m drill spacing (although there were times a closer spacing was used) at Jaguar South, Jaguar Central, Jaguar North and Onça Preta. Together, these ore bodies represent about 67% of the contained metal in the GMRE. All the core was diamond, while every hole was subjected to down-hole electromagnetic surveys.
According to Centaurus, this work correlated very well with the interpretation of the previous inferred resource. In addition to providing increasing control on the mineralised zones and grade distribution, the closer-spaced drilling also helped develop an important structural model.
The Jaguar Central and Jaguar South deposits are likely to deliver the bulk of the ore during the early years of any future operation and should underpin the project’s base line scoping due diligence.
Centaurus said Jaguar and Onça were unique in the nickel sulphide sector as the high grade mineralisation came to surface and remained open at depth. Significantly, more than 80% of the GMRE’s contained nickel is within 200m from surface.
During his appearance at the RIU show, Centaurus operations manager Roger Fitzhardinge said a second scoping study, which is set to be completed by April, would look at including pressure oxidation (POX) in Jaguar’s circuit.
“POX testing is demonstrating that we get good extraction,” he explained.
“The advantage of POX in producing the nickel metal is that you’ll get paid 100 per cent LME nickel price … which compared to the pay abilities that you might get for a nickel concentrate, which might be 72-75 per cent, is all in the bottom line, so it’s a very attractive case.”