Enhanced Separation Behavior of Metals from Simulated Printed Circuit Boards by Supergravity

Abstract

Printed circuit boards (PCBs) contain valuable metals, epoxy resin, and glass fiber, resulting in them being considered as attractive secondary sources of metals. Due to the complex metal compositions in PCBs, it is difficult to clarify the mechanism of metal separation behavior in the pyrometallurgical recovery process. In this paper, pure Pb, Sn and Cu were used to simulate the effects of temperature, time, particle size and shape on the reaction and separation process. With the increase of temperature and time, the thickness of the interface reaction layer was improved. Under the same temperature and time, the reaction degree of Cu with Sn was greater than that of Cu with Pb. In the separation process, reducing temperature, time and increasing Cu particle size were conducive to the separation and recovery of Pb-Sn alloy by supergravity. Under the same or similar particle size, the recovery of Pb-Sn alloy in irregular Cu particles was lower than that in regular Cu spheres. Improving the gravity coefficient benefited the recoveries of Pb and Sn. The results will provide technical guidance for the separation and recovery of Pb, Sn and Cu from real PCBs.