Leaching Behavior of Gold from CPU chip Grinding Products in Iodide/Iodine Solution

The leaching behavior of gold from waste CPU chip using Iodide/Iodine solution was studied. The direct leaching of gold with Iodide/Iodine solution for CPU chip under the size of 150 mesh showed leaching ratio of 20%. It was assumed that the copper film was produced on the gold particle during grinding process and the copper film prevents lodine/Iodide solution from contacting with leachable gold. Meanwhile, the extraction of gold was improved to 90% by pretreatment process with solution. In order to explain the result, EDS and ICP analysis for the leaching residue were conducted. It was found that the copper coated on the surface of the gold particle was removed about 80% by , resulting in the increment of gold leaching rate.