Estrella Resources Limited (ASX: ESR) has upgraded the 5A Mineral Resource Estimate (MRE) at the company’s Spargoville Nickel Project, located approximately 20km southwest of Kambalda, Western Australia.
The update takes into account recent metallurgical drilling below the existing 5A open pit conducted from May to July this year which assisted in defining mineralisation types and depths. The drilling also firmed up massive and matrix sulphide widths, mineralogy and bulk densities which are required to be well understood prior to mining.
The upgrade in comparison to the 2019 MRE saw the bulk of tonnes shift into the Measured Resource in the area below the pit which Estrella is targeting for production. There was also an increase in the amount of Transitional material.
I am pleased to report this resource upgrade offers continued evidence of the quality of the Spargoville 5A resource,” Managing Director, Chris Daws, said.
“Compared to the 2019 MRE, the upgrade highlights a shift of bulk tonnages into the Measured Resource category in the area immediately below the open pit which we are targeting for production and an increase in the amount of Transitional material which had previously been classified as Fresh has been outlined.
“Following the upgrade, we have now begun optimisation work to inform a Definitive Feasibility Study targeting 16,000 tonnes of Massive Sulphide grading 7.8% nickel below the existing 5A open pit. We remain firmly on target in bringing Spargoville into operation next year should the DFS be favourable.
“As has been repeated to me by many a miner, grade is king! 5A delivers on this metric and at current nickel prices is certainly worth pursuing development.”
Estrella is particularly focussed on the 16kt of Massive grading 7.8% Ni which lies below the pit floor and is accessible via a pit cut-back.
Mineralogical analysis of the core showed the bulk of the nickel in the massive sulphide below the open pit resides in violarite with additional nickel coming from sulphates, carbonates and then silicates. This confirmed the company’s view that traditional flotation would suffer unacceptable soluble nickel losses as highlighted by flotation test work. Sulphides are predominantly violarite with minor pyrite and marcasite. The sulphates are also nickel bearing.
The alternative treatment method sought by Estrella has been shown through testing that the vast majority of nickel can be successfully extracted, including the silicate and soluble fractions. The 2,000t to 4,000t bulk sample will help the Company to quantify nickel, copper and cobalt recoveries for the DFS.
Inclement weather and a shortage of suitable machinery and contractors in the Goldfields has seen a slight delay of the extraction of the bulk sample. The company expects the sample to be mined in the current quarter with pre-mining site works already commenced with ramp access, pit floor preparation and ore mark-up underway.
A short drill-blast programme followed by extraction of the first ore bench will be undertaken by local contractors under the supervision of company representatives and consultant mining specialist. High-grade nickel ore will be placed onto the 5B ROM pad where it will be crushed/screened to required size before being transported by road train to the desired treatment facility for processing and recovery of the nickel metal.