Prediction Model for Cu Chemical Leaching from Printed Circuit Boards

A kinetic study of the process for the copper leaching from a printed circuit board, by Fe3+, was reported. A mathematical model, supported by experimental data, considered the mechanisms that control the reaction (chemical reaction, particle or liquid film diffusion). The kinetic of the chemical reaction was studied by two models (pseudo-first and pseudo-second order), with a calculated activation energy of 18-25 kJ/mol. Nevertheless, both the models showed two criticalities: the Cu concentration dependence from the Fe3+ and the Fe3+ reducing rate. Therefore, a new mathematical model was proposed to predict the recoverable Cu from PCB, by three parameters: the Cu content, the Fe(3+ )concentration, and the temperature. The high reliability of the model makes it an essential tool for urban mining process optimization.