Track: Senior Design Competition / FYP Competition

Abstract

Electronic waste (e-waste) is a potential source of valuable and critical materials such as gold, silver, platinum group metals, copper, and rare earth elements. In Canada, however, less than 20% of generated e-waste is recycled. There exists a need for an efficient, sustainable e-waste metal recovery process that could be deployed on a regional scale to incentivize collection and recycling. In this paper, a process model was developed in MATLAB to simulate the electrochemical recovery of base and precious metals from printed circuit boards (PCBs) using regenerated Fe³⁺ oxidant. In the modelled process, Fe³⁺ ions are regenerated at the anode of an electrolytic cell while extracted metals are recovered on the cell cathode. A two-stage process using unique electrolyte solution for each allows base metals (Cu, Sn) and precious metals (Ag, Au, Pd) to be recovered separately. The process model was able to predict economic and environmental performance of the process given a set of feed conditions and operating parameters. Monte Carlo analysis and sensitivity analysis were used to determine key operating parameters and optimal setpoints for a final design. The final design was environmentally and economically feasible, with an estimated net annual profit of CA$ 321,000 after tax, and a carbon intensity 57.7% lower than the conventional pyrometallurgical process used for e-waste metal recovery.