Caracterização físico-química de Placas de Circuito Impresso (PCI) de computadores desktops obsoletos

Abstract

Industrial development was essential for the emergence of countless technological innovations that were and continue to be important for contemporary society, for example the invention of electronic equipment (EEE) such as cell phones and computers. However, the unrestrained consumption of this equipment causes the accumulation of millions of tons of waste from electrical and electronic equipment (WEEE) such as printed circuit boards (PCB) which are made up of various components such as valuable metals (gold and silver), metals base (copper and tin) and toxic substances, therefore the objective of this study was to characterize six PCBs of different models through mechanical processing and physical-chemical characterization techniques (incineration and acid digestion). As observed, mechanical processing proved to be efficient since the accumulated mass loss, at the end of all stages, was 2.1%. Through incineration and acid digestion it was observed that the composition, by mass, of the ground plates is 23.25% ceramic, 30.68% metals and 46.07% polymers. The granulometric analysis of the overall PCB sample and the samples separated by components (ceramic, metal and polymer) resulted, respectively, in average Sauter diameters of 0.1508 mm, 0.1063 mm, 0.1866 mm and 0.1285 mm. Finally, the data from sieving were adjusted to the particle size distribution models of Gates, Gaudin and Schumann (GGS) and Rosin-Rammler-Bennet (RRB), thus, based on the determination coefficients (R²) it was found that the RRB model fitted better in the four cases analyzed, thus the coefficients found were 0.8695 for the ground PCB sample, 0.8099 for the ceramic fraction, 0.8764 for the metallic components and 0.8401 for the polymeric fraction