Gold Recovery from Waste Printed Circuit Board Iodide Leachates Using A Novel Membrane-Based Electrowinning Process

Abstract

Ngeleka Marco Mukuna, Jochen Petersen and Thandazile Moyo

The hydrometallurgical recovery of gold from waste printed circuit boards is considered a promising recycling technique. This paper presents the findings from a study investigating the feasibility of a hydrometallurgical technique to recover gold from waste printed circuit boardiodide leachates using a novel membrane-based electrowinning process. Findings showed that the investigated novel process has the potential to be technically feasible if employed in a real life industrial-scale waste printed circuit board recycling operation. This is primarily because high purity (>99%) Au was effectively recovered using the investigated process with a 95.50 % yield under the following conditions: 6.0 hrs time, constant cell voltage of 12.9 V, temperature of 25 o C, 250 rpm agitation speed, average current of 5 A, 1429 A/m2 equivalent current density, and 8.4 × 10-6 mol/m2.s Au flux. Overall, the simultaneous recovery of iodide lixiviant with Au makes the recovery process simple as well as potentially cost-effective. Further studies on the process scale-up are required to accurately evaluate the overall costing of the gold recovery process via the proposed technology.

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