PERTH -Herald Resources said today that positive metallurgical testwork on the Lae Jehe deposit showed it would have similar zinc and lead recoveries at the same stage of the process as those so far achieved at the Dairi project’s Anjing Hitam deposit which has reserves of 6.5 million tonnes grading 14% zinc, 9% lead and high grade silver.
The resource at Lae Jehe is 6.5 Mt @ 11% zinc and 6% lead. “Results from testwork on material from one Lae Jehe drill hole have been very encouraging,” said executive director Michael Wright.
“The sample intentionally included 19% dilution with hanging wall and footwall material and was subjected to laboratory batch flotation testing to simulate the circuit of the concentrator for the Anjing Hitam ore.
Both projects are about 100 kilometres south west of Medan. Dairi has been a project that Herald has been working on since the beginning of this decade after the company exited from gold mining and milling at Coolgardie in Western Australia.
Wright said the latest results help confirm Herald’s belief that Lae Jehe could provide mill feed that would take the Dairi project significantly beyond its initial planned mine life of seven-years. Both projects are 80% owned by Herald, with local diverse miner PT Antam Tbk holding 20%.
West Perth-based mining research group Intierra said that studies on Anjing Hitam had shown the project would cost USUS$678 million, would have net operating cash flow of USUS$228 M and have mining-pre production costs of USUS$16.9 M with plant and infrastructure to cost USUS$60.8 M.