South America-focussed platinum group metals project developer Jangada Mines announced positive results from its recent metallurgical test work on Monday, which was initiated to establish the optimal process flow sheet for the recovery of precious and base metals including chrome.
The AIM-traded firm said the results demonstrated that the inclusion of magnetic separation could "materially positively impact" the economics of its Pedra Branca platinum group metals project in north-eastern Brazil.
It said the initial conventional test work yielded "strong" results in line with open pit PGM projects in South Africa, the world's largest regional PGM producer.
The addition of magnetic separation increased recoveries of PGM, the board explained, and yielded "unexpectedly high" gold and chrome grades in pre-concentrate with samples demonstrating pre-concentrate PGM grades up to 8.1 g/t, average gold grades of 15 g/t, with the highest being 75.5 g/t, and pre-concentrate chrome (Cr2O3) grades of 42%.
Magnetic pre-concentration would now be incorporated into an optimised flow sheet, expected to result in further significant efficiencies than originally anticipated including reduced plant size, capital expenditure and operational expenditure.
Jangada said economic studies were expected to be completed "imminently", and were anticipated to positively reflect the recent 53% increase in platinum group metals resource to 1.45 million ounces, as it announced on 15 May, and results from the metallurgical tests.
"The potential of this project keeps improving," said chairman Brian McMaster.
"These metallurgical tests not only underline the current potential but highlight that, with the inclusion of magnetic separation in a processing circuit, we can significantly improve the economics of Pedra Branca."
McMaster said that, on conventional processing, the platinum group metals recoveries were already in line with the world's low-cost producers' recoveries, with metal credits including nickel, copper and cobalt adding further value.
"With magnetic separation, we can raise general recovery rates and reduce the feedstock requirements for recovery/production targets, which in turn lowers the capex and opex numbers.
"The unexpected recovery rates from gold were a further bonus," he quipped.
"We are now looking to include these findings into future studies, which when finalised will demonstrate the true potential of South America's largest PGM project."