Canadian junior Eloro Resources says an “exceptionally high” level of early metallurgical and pyrometallurgical work on an initial mineral resource estimate for its Iska Iska silver-tin project in Bolivia is justified by the scale of the MRE and will enable it to move forward rapidly with a preliminary economic assessment announced this week.
The work includes preliminary ore sorting tests at a Tomra facility in Germany said to have produced favourable results that will be fed into the PEA process.
Eloro said the PEA study by leading Australian engineering firm, Lycopodium, would use its inferred near-surface MRE of 560 million tonnes grading 13.8 grams per tonne silver, 0.73% zinc and 0.28% lead in Iska Iska’s polymetallic domain and 110Mt grading 0.12% tin, 14.2gpt silver and 0.14% lead in a tin domain.
“While the polymetallic domain and the tin domain do not overlap or share any resource blocks, for the purposes of the PEA the mineral resources within both domains will be combined,” the company said.
Eloro said in July this year “substantial metallurgical work” on samples from both domains indicated Iska Iska mineralisation was amenable to ore sorting, “with removal of at least 40% of the waste in the polymetallic domain and up to 80% in the tin domain”.
This might “substantially increase concentrator feed grades as well as reduce future operating costs and significantly lower the cut-off grades for the mineral resource estimates and the PEA”, it said.
“Further metallurgical studies conducted by Wardell Armstrong International on a composite sample of the tin mineralisation has improved tin concentrator stage recovery to 50%.
“This recovery is un-optimised and has been achieved using a mixture of multi-gravity and tin flotation techniques which are specifically designed to recover the finer grained cassiterite.
“The concentrator could produce an approximately 5% tin concentrate grade amenable to the tin fuming process that ultimately could produce a 60-70% tin concentrate for smelting.”
Eloro CEO Tom Larsen said further resource definition drilling would aim to extend higher-grade zones of mineralisation as well provide material for more definitive ore-sorting tests.
“We are delighted to commence the PEA study on Iska Iska just three years after we began our initial exploration drill program,” he said.
“This is another major step in moving the development of Iska Iska forward.”
Eloro is earning 100% of Iska Iska, 48km north of Tupiza in southern Bolivia.
It identified the Santa Barbara Brecia Pipe, in September 2020, only about 150m south-west of where it first began underground diamond drilling on the former Huayra Kasa underground workings at Iska Iska.
The Toronto-listed company has a current market value around C$142 million.