Affiliation:
1. Faculty of Metallurgy and Energy Engineering Kunming University of Science and Technology Yunnan Provincial Key Laboratory of Intensification Metallurgy Key Laboratory of Unconventional Metallurgy, Ministry of Education Kunming University of Science and Technology Kunming 650093 Yunnan China
2. Faculty of Metallurgy and Energy Engineering Kunming University of Science and Technology Yunnan Provincial Key Laboratory of Intensification Metallurgy Key Laboratory of Unconventional Metallurgy, Ministry of Education Yunnan Copper Co., Ltd. Kunming University of Science and Technology Kunming 650093 Yunnan China
3. Faculty of Metallurgy and Energy Engineering Kunming University of Science and Technology Yunnan Provincial Key Laboratory of Intensification Metallurgy Kunming University of Science and Technology Key Laboratory of Unconventional Metallurgy Ministry of Education State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization Kunming University of Science and Technology unming 650093 Yunnan China
Abstract
AbstractBromine in waste printed circuit boards has caused serious harm to the environment. How to deal with it safely is a problem. In this paper, the debromination of waste printed circuit boards by microwave gasification pyrolysis was studied, and the properties of pyrolysis products and the migration of bromine were analyzed. The optimum pyrolysis conditions of microwave steam atmosphere were 600 °C, 1000 W, 50 min, 2 mL/min. Compared with conventional pyrolysis and conventional steam pyrolysis, less solid products (60.39 wt %) were obtained, and more metal copper was enriched. The content increased from 27.46 % and 28.35 % to 30.63 %, respectively, and the diffraction peak intensity of copper was also enhanced. There is no obvious change in the type of functional groups of the solid product, and its microscopic morphology is smoother. Compared with conventional pyrolysis, the phenolic compounds in pyrolysis oil decreased, and increased compared with conventional steam pyrolysis. The content of H2 in the pyrolysis gas increased significantly, and the content of CO decreased significantly. Compared with conventional pyrolysis, the bromine content in pyrolysis gas and pyrolysis oil decreased from 94.5 % and 5.5 % to 1 %, respectively, and more bromine (98 %) in the raw material entered the aqueous solution.