With initial metallurgical testwork of uranium samples yielding recoveries of up to 93% using conventional acid leaching methods from Aura Energy's (ASX:AEE) Häggån Uranium-Molybdenum-Vanadium Project in Sweden, this identifies a significant boost for the future of the project.
From the testing, the majority of the uranium was extracted in the first 12 hours of leaching, with this initial success allowing Aura to move to project forward to the next stage.
Aura will now test the effectiveness of the leaching at lower temperatures, as well as the impact of leaching coarser grain sizes, along with other varying key leaching conditions.
Aura also requested the Australian Nuclear Science and Technology Organisation, (ANSTO) to carry out bottle roll acid tests at lower acidity at minus two millimetres, to continue to assess the amenability of the Häggån sample to heap leaching.
The company commenced bioleaching testwork with the Parker Cooperative Research Centre for hydrometallurgical research in Perth, Western Australia, in late 2009.
Bacterial cultures have been established from three sources: the ore; waters from the project area in Sweden; and from a coal mine in Western Australia, with initial work demonstrating improved extraction rates of uranium, molybdenum, nickel and zinc using bacteria, relative to samples without bacteria.
Consequently, these initial results indicate the Alum Shales within the project are likely to be amenable to bioheap leaching, which Aura said that this extraction method will potentially provide a low capital and operating cost treatment route.
Of major importance, the JORC first inferred resource of 291 million pounds of U3O8 covers only five per cent of total project area, highlighting the projects resource upside potential.
Aura also has other uranium projects in Australia and the highly prospective West Africa region.