The recovery of copper (Cu 0 ) from waste printed circuit boards (WPCBs) is a great challenge as a result of its heterogeneous structural properties, with a mixture of metals, epoxy resin, and fiberglass. In this study, a three-step sequential process, including mechanochemical processing, water leaching, and recrystallization, for Cu 0 recovery from WPCB powder is reported. Potassium persulfate (K 2 S 2 O 8 ), instead of acid/alkali reagents, was employed as the sole reagent in the cupric sulfate (CuSO 4 ) regeneration process. Complete oxidation of Cu 0 in the WPCBs to copper oxide (CuO) and CuSO 4 was first achieved during mechanochemical processing with K 2 S 2 O 8 as the solid oxidant, and the K 2 S 2 O 8 was simultaneously converted to sulfate compounds [K 3 H(SO 4 ) 2 ] via a solid-solid reaction with epoxy resin (C n H m O y ) as the hydrogen donator under mechanical force. The rapid leaching of Cu species in the forms of CuO and CuSO 4 was therefore easily realized with pure water as a nontoxic leaching reagent. The kinetics of the leaching process of Cu species was confirmed to follow the shrinking nucleus model controlled by solid-film diffusion. Finally, CuSO 4 ·5H 2 O was successfully separated by cooling crystallization of the hot saturated solution of sulfate salt [K 2 Cu(SO 4 ) 2 ·6H 2 O]. An efficient conversion of Cu 0 to CuSO 4 ·5H 2 O product, for WPCB recycling, was therefore established.