- Leach tests using 1m columns performed exceptionally well
- Rapid leach kinetics; good nickel and cobalt recovery; low acid consumption
- Nickel extraction of 73-82% within 30 days and 86-92% after 100 days
- Cobalt extraction up to 60% within 30 days and 80-85% after 100 days
- Tank leach tests gave 80-85% nickel extraction within 8 hours
African Eagle’s Managing Director Mark Parker comments, “We are delighted with the results of our phase 2 column and tank leach tests, which show that Dutwa ore could be processed by either heap leaching or tank leaching at normal atmospheric pressure, without recourse to the high cost and hi-tech complications of high pressure acid leach (HPAL).
“The leaching reaction proceeds very quickly, especially for the first two-thirds of the contained nickel, and the acid consumption is much lower that for comparable deposits elsewhere. This opens a wider range of leach options and, if heap leaching is used, implies that working capital should not be tied up for a long period while the heap reaches full productivity.”
African Eagle has now received the final results for the second phase of metallurgical testwork carried out as part of African Eagle’s pre-feasibility study on Dutwa. The tests were performed by Mintek Laboratories in South Africa on 250 kg of sample taken from seven drill cores from the main Dutwa nickel deposit (Wamangola Hill). They included column and tank leach tests, preliminary agglomeration tests and preliminary ore characterisation tests. Details of the tests and results may be found on the Company’s web site.