Recovery of gold from hydrochloric acid by means of selective coagulation with persimmon extract

Gold was selectively precipitated with solution of persimmon extract which contains persimmon tannin, a kind of polyphenol. Quantitative recovery of gold was achieved in the concentration range of hydrochloric lower than 0.5 mol.dm(-3). X-ray diffraction analysis and a digital micrograph of the filtered cake indicated the formation of gold particle during recovery process. High selectivity of persimmon extract is ascribed to the reduction of Au(III) to elemental form.