Gold Mining Given a Green Makeover

It is amazing how scientists can turn defeat into victory. Cleantechnica have an interesting article about Zhichang Liu, a postdoctorate working at the Weinberg College of Arts and Sciences at Northwestern University, who, whilst experimenting to create a three dimensional cubic nano-structure that could store gases and other small molecules, discovered a new method of extracting gold from crude sources.

The gold mining industry is one of the most environmentally damaging in the world, mostly due to the use of deadly cyanide as means to separate gold from the raw sources that it is often bound to.

Liu’s new method uses simple cornstarch, instead of cyanide, to effectively strip the gold particles from a large variety of crude sources. This cuts down on the environmental  contamination, and reduces the health problems for those involved in the gold mining process.

Sir Fraser Stoddart, the Professor of Chemistry as the Weinberg College of Arts and Sciences, said that “the elimination of cyanide from the gold industry is of the utmost importance environmentally. We have replaced nasty reagents with a cheap, biologically friendly material derived from starch.”

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In his search for a three dimensional cubic nano-structure Stoddart explained that Liu “took two test tubes containing aqueous solutions — one of the starch-derived alpha-cyclodextrin, the other of a dissolved gold salt (called aurate) — and mixed them together in a beaker at room temperature.”

He hoped to see his cubic structure form in front of his eyes, but instead watched as needles appeared. He admits disappointment at first, but after further studies that quickly became excitement, as he realised that the needles were formed from gold which had been split from the initial solution.

Not only does this technique avoid the use of cyanide, but it is also quite a bit more efficient than current practices.

By. Charles Kennedy of Oilprice.com