Salazar Resources Limited (CVE:SRL) and partner Adventus Mining Corporation (CVE:ADZN) (OTCMKTS:ADVZF) posted Thursday positive findings from metallurgical testing for the Curipamba project in Ecuador, which showed improvements from last year's preliminary economic assessment (PEA).
The tests used the same three composite samples taken from the 2018 infill drilling program at the El Domo volcanogenic massive sulphide (VMS) deposit at the Curipamba property.
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Salazar is fully carried to production at Curipamba and the El Domo copper, gold, zinc deposit. It owns 25%, while partner Adventus has 75%. The latter must fund exploration worth US$25 million before October 2022.
The aim of the tests was to improve the quality of the concentrates by reducing metal cross-contamination and all three samples show improved copper concentrate quality and marketability, said Salazar in a statement.
Meanwhile, leach test work of the cleaner tailings streams of all three composites using cyanide indicated that gold and silver recovery could be significantly increased.
The deposit may be a candidate for what's called a sulphidization-acidification-recycling-thickening (SART) process that would also recover additional copper while significantly reducing reagent consumption, added the firm.
In addition, all waste rock from the open pit was previously assumed to be acid generating in last year's PEA but new studies have shown that three key strata in the hanging wall rocks are non-acid generating.
Lead concentrate possible
Finally, the metallurgical work showed that production of a lead concentrate from both the mixed and zinc composites was possible.
Significantly, this could improve the quality of the copper and zinc concentrates, reduce waste, and potentially offer a saleable lead concentrate by-product.
The PEA last year showed a post-tax net present value (NPV) of US$288 million with pay-back of less than two years and 40% post-tax IRR (internal rate of return).
A resource estimate for El Domo pegged the higher confidence indicated resource at 7.5 million tonnes at a grade of 2.02% copper, 0.26% lead, 2.81% zinc, 2.33 grams per ton (g/t) gold and 49 g/t silver.
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