Development of an Electrolytic Process f

In an experimental study design with laboratory analysis, printed circuit boards (5 kg) of obsolete television were ground and sieved to obtain 2 mm particle size. Chemical leaching of copper using different concentrations of nitric acid (1 mol, 3 mol, 5 mol and 7 mol) was carried out at varying time intervals (0 h, 12 h, 24 h and 48 h). Leachate obtained was subjected to electrolysis to recover copper using a prototype electrolytic cell designed and fabricated locally. Bioleaching was carried out through composting process for four weeks using market wastes and cow dung under mesophilic conditions. Chemical leaching yielded higher copper (236 187.6 ± 0.4 mg kg-1) than that leached biologically (74.4 ± 0.1 mg kg-1). Electrolytic extraction showed that the mean weight of copper deposited at 1 Mol acid extraction (683.3 ± 2.6 mg) was significantly higher than that deposited at 3 mol concentration of electrolyte (366.7 ± 2.6 mg). Also, copper extracted electrolytically from chemical leachate (366.7 ± 2.6 mg) was higher than that extracted from biological (36.8 ± 1.8 mg) at 3 mol of electrolyte. Bioleaching is a very slow process and the yield depends on method of leaching, current, voltage, electrolyte concentration, time and electrode types. These factors play an important role in electrolytic recovery of copper from e-wastes.