An updated preliminary economic assessment for Panoro Minerals Ltd.'s Antilla copper property in Peru improved the project's value and reduced costs, according to a May 14 release.

The mine plan focused on the higher grade, near-surface secondary sulfides, which can be processed using heap leaching, solvent extraction, and electrowinning. This approach showed a 59% decrease in initial capital costs to US$250.4 million, while the sustaining capital required for a tailings facility was eliminated.

Using a copper price of US$3.05/lb and applying a 7.5% discount rate, the project's after-tax net present value rose to US$305.4 million from US$225 million previously, while the internal rate of return now stands at 25.9%. The payback period was also reduced to 3.0 years from 4.1 years.

The project is estimated to produce 46.3 million pounds of copper per year over a mine life of 17 years. The designated throughput, meanwhile, was pegged at 20,000 tonnes per day.

The study incorporated indicated resources of 113.3 million tonnes averaging 0.45% copper and inferred resources of 5.4 million tonnes at 0.26% copper. It also recommended further work leading to a pre-feasibility or feasibility study.

Panoro said it will now work to complete a strategic review of the development and financing plans for Antilla.