Scientists at Northwestern University said their method uses simple cornstarch instead of the highly poisonous cyanide nearly all gold-mining companies use in a leaching process to sequester the precious metal.
"The elimination of cyanide from the gold industry is of the utmost importance environmentally," chemistry Professor Fraser Stoddart said in a university release Tuesday. "We have replaced nasty reagents with a cheap, biologically friendly material derived from starch."
The new method does create alkali metal salt waste but that is relatively environmentally benign compared with waste from conventional methods that include toxic cyanide salts and gases, the researchers said.
The new process also can be used to extract gold from consumer electronic waste, they said.
The findings have been published in the online journal Nature Communications.