African Eagle Resources selects metallurgical process for Dutwa nickel project

African Eagle Resources (LON:AFE) announces that it has selected atmospheric tank leaching as the metallurgical process method to be employed at its flagship Dutwa nickel oxide project in Tanzania.
 
Having decided against the heap leaching process which had been considered in tandem, this allows the group to streamline work on the bankable feasibility study as well as on the environmental and social impact assessment (ESIA).

Extensive batch metallurgical testwork over the past two years has shown that Dutwa ore allows simplified processing: atmospheric leach methods resulted in rapid extraction without the need for the challenging and costly high-pressure acid leach technologies that have proven problematic elsewhere, the company said.

African Eagle now wants to build a pilot plant to confirm the performance of the chosen process on samples representative for the planned output from Dutwa. It is in advanced talks with Australian laboratories that can operate the pilot plant.

The test programme is to be performed later this year in Perth and will support the Dutwa BFS, which is due for completion around the end of 2012.

Ocean Securities welcomed African Eagle’s choice, saying the tank leaching option had been its preferred process route for some time, especially so after the announcement of the mineralogical test work that showed most of the nickel was hosted in the fines fraction of the ore.

Mining analyst Christopher Welch pointed out that through tank leaching African Eagle is using the good leach kinetics of the ore to extract the nickel in the shortest amount of time.

Tank leaching essentially uses off-the-shelf technology to process ore and so a scaled up version of the pilot plant is essentially location independent. Heap leaching is a more complicated method that is slightly more dependent upon location variables.

Welch also still sees potential to optimise the leaching of Dutwa ore further. African Eagle could preferentially treat the fines fraction of the ore which would reduce throughput through the later stages of the plant. “We suspect this may be decided before construction of the pilot plant,” the analyst said.

African Eagle has made good progress of finding sources for the main consumables for the project, which include limestone and pyrite, he added.

Dutwa currently has a JORC resource of 99 million tonnes at 0.93 per cent nickel, offering ready mining from two hilltop deposits.

Only last week, African Eagle hired Aidan Schoonbee as project manager for Dutwa. He has over 20 years experience in the mining industry and his most recent role was as senior project manager for De Beers associate Debswana Diamond Company.