Effect of Particle Size on the Extraction of Metallic Components from Oxidized PCB in High Frequency Induction Furnace

摘要

It is generally well known that PCB (Printed Circuit Board) is a complex mixture of various metals mixed with various types of plastics and ceramics. Accordingly, it is very important to extract metallic components from used PCB's from the point of view of recycling the used resources as well as the environmental protection. In this study, a high temperature pyro-metallurgical process was investigated to extract valuable metallic components from the used PCB's. For this purpose, used PCB's were shredded and oxidized to remove plastic materials, and then, a high frequency induction furnace was used to melt and separate metallic components in molten state from the remaining oxides. After the oxidation of the used PCB, 30.6wt% SiO_2, 19.3wt% Al_2O_3 and 14wt% CaO were analyzed as major oxides, and thereafter, a typical composition of 32wt%SiO_2-20wt%Al_2O_3-38wt%CaO -10wt%MgO was chosen as a basic slag system for the separation of metallic components Moreover, in order to understand the size effect on the extraction of metallic components, oxidized PCB's were further milled, and then, melted. As a result, it was found that the size of oxidized PCB's was needed to be less 0.9mm to make a homogeneous liquid slag and to recycle metallic components over 95%.