Growing number of electronic products, has also brought a growing number of obsolete electronics products, including gold, silver content is very high with high recovery value, the traditional method is to use aqua regia back plating, and then recovery of gold, silver, copper and nickel. This ancient method of gold recovery resulted in a lower, other metals are all back away, and complex recovery process, gold is difficult to separate from other metals, also led to other metal waste, 97 onwards, our company has been in the promotion of zinc replacement refining gold recovery method: off powder off gold - zinc or zinc wire replacement - sulfuric acid purification - smelting in pigs, this recovery was higher, reaching 99% recovery rate, but there will be purified with sulfuric acid emitting black smoke, air pollution caused by large. In 2007 we imported technology from Germany, electrolytic recovery of gold gold machine, make recovery of 99.95% purity of 99% off the sponge gold, also has cracked down most of the cyanide, wastewater treatment relatively simple.