Innovative Method for Removing Bromine in Waste Printed Circuit Boards: Ultrafine Milling and Porous Media Loaded Debromination Agent

Resin is the main harmful substance in waste printed circuit boards (WPCBs) due to the presence of harmful bromine. In this study, the methods of ultrafine milling of resin and loading debromination agent on porous gasification slag were proposed to improve the debromination effect. The morphology, composition and phase of the gasification slag and resin were analyzed by scanning electron microscope (SEM) and X-ray diffractometer (XRD). The results show that the residual carbon in the gasification slag has porous structure, which contributes to the loading of debromination agent. The specific surface area and porosity of gasification slag before and after acid treatment were analyzed by BET. Using the porous prop-erties of gasification slag, different debromination agents were attached to prepare efficient debromination agents, which were adopted for thermal debromination of resin in WPCBs. Subsequently, ICP-MS was used to determine the content of bromine in pyrolysis residue. The results show that when FeCl2/FeCl3 was used as the debromination agent, the debromination efficiency was only 67.19% and 58.29%, while using gasification slag-FeCl2/FeCl3 composite, the debromination efficiency can be increased to 81.63% and 76.25%. Therefore, the cooperative treatment can realize the resource utilization of the two wastes. (C) 2022 The Society of Powder Technology Japan. Published by Elsevier BV and The Society of Powder Technology Japan. All rights reserved.