Orvana retained DGCS S.A. (DGCS) to prepare a NI 43-101 technical report for the Don Mario Oxide Stockpile Project. The company owns the Don Mario Operation in Bolivia, assets that include the Las Tojas ore body and the previously mined out Lower Mineralized Zone, Upper Mineralized Zone and Cerro Felix mines, plus the processing plant tailings facility.
Operations at Don Mario were temporarily suspended in Q1 of fiscal 2020 and are currently on care and maintenance. The UMZ deposit, depleted in 2017, generated a 2M-tonne mixed copper oxide stockpile with gold and silver grades during its mine life. Since fiscal 2018, the company has been evaluating metallurgical alternatives to process the Oxide Stockpile.
The evaluation concluded a sulphidization circuit would maximize the value of the Oxide Stockpile. Construction of the sulphidization circuit and ancillary facilities to process the Oxide Stockpile remains subject to the favorable completion of technical and economic analysis, and availabile funding.
The OSP Technical Report highlights are Proven Oxide Stockpile Reserves of 2 million tonnes containing 120,900 oz gold, 38,438 tonnes of copper and 3.2 million oz silver. Estimated metal recoveries of the Oxide Stockpile are based on processing by sulphidization.
Capital cost for modification of the existing processing plant to process the Oxide Stockpile is approximately US$25.6 million. The unit operating cost for processing the Oxide Stockpile is estimated at an average of US$93.10/tonne.
Final evaluation of the feasibility of the Oxide Stockpile Project is planned to be completed by the end of Q3 fiscal 2021. The sulphidization circuit and ancillary facilities development is expected to take 12 months before starting commercial production and will provide three years of production for Don Mario.
Orvana retained Roscoe Postle Associates UK to prepare a NI 43-101 independent technical report on the Orovalle Operation in Spain. The report highlights a life-of-mine plan that includes oxide and skarn ore, from El Valle Boinas and Carles mines, at an average annual rate of 686,000 tonnes, for five years. Proven and Probable Reserves are 3.4 million tonnes of ore containing 307,000 oz gold, 756,000 oz silver and 27.6 million lbs copper.
Inferred Mineral Resources are approximately 3.4 million tonnes containing 410,000 oz gold, 934,000 oz silver and 24.8 million lbs copper.