Separation and recovery of gold from waste LED using ion exchange method

The separation and recovery of gold from waste LED using ion exchange method was investigated, employing commercial polyamine type anion exchanger, Diaion WA21J. Leaching of gold from LED terminal was successfully carried out with aqua regia at 80 degrees C. Separation of gold from the leaching solution was then carried out by column adsorption with WA21J. The selective adsorption of gold was achieved, while adsorption of the co-existing metals in the leaching solution was suppressed. Quantitative elution of gold from WA21J was achieved with diluted thiourea solution. Elementary gold was then obtained from the eluent by simultaneous precipitation and reduction of gold with sodium borohydride with 100% purity. (C) 2015 Elsevier B.V. All rights reserved.