AEE up ~10% on BIO-LEACH success
 

Aura Energy (ASX: AEE) has risen nicely today on the back of the news release re their Bio Heap Leach process being successfully trialed.

Using a mixture of sulphide "eating" bacteria from 3 different sources that munch on pyrite to produce sulfuric acid they obtained 75% uranium extraction.

The bio heap leach process in conjunction with their existing high levels of recovery (up to 93%) of uranium that have been obtained from initial bench‐scale conventional acid leaching tests with a 12 hour through put time, indicate that AEE is well on track towards developing a rapid, cheap method of uranium and other metals extraction.

From the release:
Bioleach Testwork Overview

Aura commenced bioleaching testwork with the renowned Parker Cooperative Research Centre for Hydrometallurgy in Perth, Western Australia in late 2009. Bacterial cultures have been established from three sources: the H?gg?n ore; waters from the Project Area in Sweden; and from a coal mine in Western Australia.

The Alum Shale material at H?gg?n has characteristics that make it amenable to bioleaching technologies. The high sulphur content, which the bacteria can oxidise to generate acid, and the similarities to ores being processed by bioleaching elsewhere, has been the impetus for this testwork programme.
Bioleaching in heaps is advantageous as the bacteria generate acid from the pyrite in the rocks, limiting the need to purchase acid and so greatly reducing project operating costs. Heap leaching also offers much reduced capital cost.
These initial results obtained by CSIRO scientists working through the world‐renowned Parker Cooperative Research Centre for Integrated Hydrometallurgy Solutions

The main objectives of these tests were to determine whether naturally occurring bacteria could break down the iron sulphide (pyrite) present to generate sulphuric acid, and whether this acid would aid the extraction of metals.

The tests were carried out in columns 50cm high and 10cm in diameter. Material used was quarter core, with a diameter of less than 25mm.

The tests successfully demonstrated that these objectives have been achieved. The results are from the first phase of column tests, which are designed to simulate conditions in a heap leach process.
Maximum recoveries of metals obtained in the presence of bacteria were:
Uranium 75%
Nickel 65%
Zinc 60%
Molybdenum 25%

The recoveries were significantly higher than reference tests without the presence of bacteria. The tests indicated that acidity increased rapidly when the bacteria were added, and extraction was significantly improved for all metals.

It is anticipated that these recoveries will be improved with further tests. One opportunity for improvement is using a finer particle size, as would be normal for a heap leach operation.

Aura is now planning for a larger size, more comprehensive phase of testing, which will commence later this quarter.

I hold AEE and feel that it is a likely contender that may well go head to head with Extract Resources.

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