Engineering Innovation Podcast and Radio Series


PostedMarch 16, 2008

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Randy Atkins:  The world's easy-to-get gold is being rapidly depleted.  Corale Brierely, a Colorado engineer, says much of the rest is in scattered tiny pieces within rocks of iron sulfide.

Corale Brierley:  The role of the microorganisms is to break down the iron sulfide, in sort of a pre-treatment process, to expose those small gold flecks.

Randy Atkins:  That gold can then be dissolved out in chemical solutions, and reconstituted later.  The harmless bacteria come from natural sources, like hot springs, and you don't need many.

Corale Brierley:  Since the organisms are in the presence of their most desirable food, which is sulfur and iron, they continue to grow.

Randy Atkins:  Brierley says it's cheaper and greener than more common extraction methods.  With the National Academy of Engineering, Randy Atkins, 103.5 FM, WTOP Radio.