The innovative 'green' gold mining method bids adieu to toxic cyanide

CHICAGO (Scrap Monster) : The scientists at the Northwestern University in Illinois are reported to have come across a breakthrough technique that uses cornstarch in place of cyanide to extract gold from raw materials. The technology is claimed to be useful for segregating gold from consumer electronic waste.

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

This discovery heralds a green host–guest procedure for gold recovery from gold-bearing raw materials making use of α-cyclodextrin—an inexpensive and environmentally benign carbohydrate. Sir Fraser's team discovered the process by accident, using simple test tube chemistry.

The most commonly used process for gold recovery involves the use of highly poisonous inorganic cyanides for leaching purpose. Application of cyanide leaching to gold recovery has often resulted in contamination of the environment from accidental leakages and exposures. Developing processes for gold recovery using green methods may lead to procedures which will become more economically viable than the current ones.

The findings of the research are published online in the multi-disciplinary journal ‘Nature Communications’.