Column leach test work on supergene secondary sulphide ores at the 100%-owned copper project, in Southern Peru, has indicated up to 77% copper recoveries are possible.
The number improves on the 72.5% incorporated into the May preliminary economic assessment (PEA) for the project, and which was derived from bottle roll and mineralogic test work available at the time.
As a result, Panoro advised 75% copper extraction in 200 days is an appropriate figure to use for the PEA-level studies.
"A potential increase in recoveries will further enhance the economics of this already robust project," president and CEO Luquman Shaheen said in a statement.
Panoro is planning further testing as part of feasibility studies for the Antilla project.
The company is currently reviewing strategic alternatives to advance the Antilla project to the feasibility stage, including permitting and development.
The news Tuesday sent Panoro's Toronto-quoted equity rise 4% to C26c (US20c) a share, for a market valuation of C$68.32 million.