Chile gold explorer Tesoro Resources (ASX: TSO) reports that detailed metallurgical test work on drill samples from the Ternera deposit at the company’s El Zorro project have shown high gravity and cyanide leach gold recoveries of up to 98%.
Tests were done with gravity gold and cyanide leach recoveries at four different grind sizes — 250, 200, 150 and 75 microns — and recoveries for all four exceeded 90% when leached in sea water over a 24-hour period.
These results are consistent with previously announced test work in June and the company said they confirm the potential for processing using a conventional crush, grind, gravity recovery and leach flowsheet.
‘Exceptional’ test results
Tesoro managing director Zeff Reeves described the results as “exceptional”.
“The results confirm high gravity and cyanide leach recoveries that can be achieved for processing of material from Ternera using very simple, conventional gravity and cyanide-in-leach (CIL) processes at a very coarse grind size,” he added.
“The recoveries we are seeing, particularly at the coarse 200-micron grind size, are exceptional and offer considerable cost and operational advantages to a future mining operation at El Zorro.”
Tests will underpin a preliminary project flowsheet
Mr Reeves said the work will enable Tesoro to develop a preliminary project flowsheet and continues to de-risk the project as it advances toward development.
A total of 518kg of mineralised rock samples were collected from 53 diamond drill holes at Ternera, representing each of the mineralised and grade zones within the resource.
Tesoro was established with a strategy of acquiring, exploring, and developing mining projects in the Coastal Cordillera region of Chile.
The Coastal Cordillera region is host to multiple world-class copper and gold mines and has well established infrastructure, service providers and an experienced mining workforce.
Tesoro notes that large areas of the Coastal Cordillera remain unexplored due to the previously unconsolidated nature of mining concession ownership.
Tesoro’s 95%-owned Chilean subsidiary owns 85% of the El Zorro gold project.