exploration targets of 7,600 to 13,000 tonnes , page-6

Posted: Monday , 12 Jul 2010

Perth -


Energy and Minerals Australia reports that ANSTO Minerals* has successfully completed scoping study level process development testwork for the recovery of uranium from lignite and sandstone hosted material at the Mulga Rock Deposits. The testwork demonstrated that reasonably high uranium extraction can be achieved using conventional commercially proven processing methods.

Process Route

ANSTO Minerals assessed a range of process routes, including direct acid leaching, and acid or alkaline leaching after ore pre-treatment by either calcination or pyrolysis.

The currently favoured process route is:

? Whole ore acid dissolution, followed by

? Resin-in pulp (?RIP') extraction.

Recovery

It is pleasing to note the high recoveries from this process route. Both the lignite and sandstone hosted material (Ambassador deposit) exhibited reasonably high extraction with low reagent use. In the lignite hosted material, which will be mined by conventional open pit mining, a recovery of 82% was achieved on samples with an average grade of 2,378 ppm U3O8. A recovery of 83%, on samples with an average grade of 323 ppm U3O8, was achieved in the sandstone hosted material which is likely to be mined by insitu recovery.

Continuing Development

As EMA progresses into the Pre-Feasibility Study for the Mulga Rock Deposits, ANSTO will continue development of the treatment route to optimise processing conditions, in particular:

? Leach optimisation with respect to temperature, grind size and reagent dosage

? Optimisation of the resin-in-pulp process.

EMA Managing Director Chris Davis said that the ANSTO Minerals' work was a very positive confirmation that uranium can be recovered at high recoveries from lignite.

* ANSTO Minerals, part of the Australian Nuclear Science and Technology Organisation (ANSTO), has a thirty year track record specialising in uranium ore processing. ANSTO Minerals has had continuous involvement with Australia's existing uranium producers since start up. In addition the organisation has carried out extensive work for numerous deposits under development both in Australia and internationally. ANSTO is recognised world wide as a pre-eminent expert in Process Development of uranium ores.

The ANSTO Minerals team, led by Dr Bob Ring, is made up of more than sixty professional scientists and technicians with expertise in chemical engineering, metallurgy, mineralogy, chemistry, geology and radiation safety