Statistical Evaluation of Recovery of Copper from Printed Circuit Board (PCB) by using Hydrometallurgical Method and RSM Model

This manuscript deals with copper recovery from PCB by using hydrometallurgical methods and its evaluation by developing a quadratic model using Box–Behnken experimental design and Response Surface Methodology (RSM), considering the factors: the concentration of H2SO4 (X1) and H2O2 (X2), the solid (X3)/liquid ratio, time (X4), and temperature. Hydrometallurgical methods are more predictable and calculative compared to pyrometallurgical methods. RSM is a collection of statistical and mathematical methods useful for modeling and analyzing engineering problems employed in this study. By the hydrometallurgical method, 85% of copper can be recovered from 20.09% available in printed circuit boards (PCB). A total of 27 experiments were performed under Box-Behnken design, and a model was developed for optimizing copper recovery. A second-order polynomial model was created using multiple linear regression analysis. This study shows RSM, based on the Box-Behnken method, is a valuable tool for optimizing operating parameters for copper recovery via leaching process. The statistical data summary fit shows R Square is 0.99, indicating a better fit to the data, while Adjusted R Square of 0.98 also indicates better correlation in models with all variables, and Root Mean Square (RMS) estimates the standard deviation of random error, observed at RMS 2.91 with a mean of response for 27 observations at 60.06.