Abstract
The invention provides a method for recovering metal from printed circuit boards by using hydrochloride acid which adopts a hydrometallurgical process to recover precious metals from waste printed circuit boards. To simplify the metal leaching process, large pieces of PCBs were used instead of a pulverized sample. The chemical coating present on the PCBs was removed by sodium hydroxide treatment prior to the hydrometallurgical treatment. Among the leaching reagents, hydrochloric acid showed great potential for the recovery of metals. Increasing the acid concentration decreased the time required for complete metal recovery. The shaking speed showed a positive effect on metal recovery. The results showed that 1 M HCl dissolved and then recovered all of the metals from 4×4 cm PCBs at 25℃ and 150 rpm shaking speed lasting for 22 h.