The optimised process flowsheet reduced the overall capex figure to US$43. 9 million and also lowered the plant capex by 38% to $54.2 million.

The company said the updated flowsheet, delivered in partnership with Consulmet Metals, demonstrated a simpler and more efficient process than previously envisaged and would form the basis of future test and design work to advance the project towards bankable feasibility study level.

Pedra Branca has an upgraded JORC-compliant resource of about 1.45 million ounces of PGM and gold at a grade of 1.3g/t PGM-plus gold, 140 million pounds (635 tonnes) of nickel, 26Mlb of copper and 6.7Mlb of cobalt.

Jangada chairman Brian McMaster said the refinement and optimisation of the process flowsheet and the subsequent reduction in plant capex and overall capex enhanced the project's "potential to provide lucrative returns".

"As we extrapolate the revised capex number into the already robust economic model, the financial merits of Pedra Branca will simply get stronger. Importantly, the revised process flow sheet has demonstrated a simpler and more efficient process route. We anticipate that this will reflect in reduced operating cost metrics that will feed into the ongoing BFS," he said.

Jangada's shares jumped 5.17% on the news to 2.44p (US3.14c).