Bioleaching shows promise for Swedish U

24 August 2010

Bacterial-assisted leaching of uranium from the Haggan uranium deposit in central Sweden may be technically feasible, would-be developer Aura Energy has announced. Initial work has shown that the presence of bacteria improves extraction rates for uranium, molybdenum, nickel and zinc from the alum shale deposit, with results indicating that the shales are likely to be amenable to bioheap leaching. Conventional acid leach recoveries of up to 93% have been reported for uranium from Haggan. The high sulphur content of the Haggan deposit prompted Aura to look into bioleaching technologies, where bacteria are used to acidify and oxidise ores. The tests were carried out at the Parker Cooperative Research Centre in Perth, Western Australia, where studies will now be extended to increase confidence in the technical amenability and economic viability of the bioheap leaching option. Aura recently announced the first JORC-compliant inferred resource figures of 291 million pounds U3O8 (112,000 tU) for the Haggan deposit, previously known as Storsjon.