Possibility of adsorption losses of target metal ions to fiberglass particles in the printed circuit board leaching pulp have been raised. Reports on behavior of fiberglass particles in this leaching pulp are rare. In this study, using clean fiberglass powder in amine leach solutions of waste printed circuit board of different concentrations, copper and zinc concentrations changes were monitored over time to confirm metal losses to the particles. The interaction was studied against various adsorption isotherm and kinetic models. Of the seven non-linear adsorption isotherm models employed, Sips adsorption isotherm model best fitted the experimental data with R2 of 0.9999 for Cu and 0.9848 for zinc. For the five non-linear adsorption kinetic models studied, Avrami model fitted the experimental data best with R2 of 0.9617 and 0.9503 for copper and zinc, respectively. This implies adsorption losses to fiberglass particles involve both physisorption and chemisorption. Adsorption capacity of the fiberglass powder in this instance was determined to be 0.6 mg/g for Cu and 0.035 mg/g for Zn. Process improvements based on these insights will be needed to achieve cleaner leach residue and improved recoveries.
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