Leaching of metals from waste printed circuit boards (WPCBs) using sulfuric and nitric acids
|dc.identifier.citation||Kumar, M. and Lee, J. and Kim, M. and Jeong, J. and Yoo, K. 2014. Leaching of metals from waste printed circuit boards (WPCBs) using sulfuric and nitric acids. Environmental Engineering and Management Journal. 13 (10): pp. 2601-2607.|
This study aims to understand the acid-leaching behavior of metals from 2 to 4 mm waste printed circuit boards (WPCBs) containing 22.0% ± 1.1 Cu, 6.7% ± 0.2 Ca, 0.68% ± 0.02 Sn, 0.59 ± 0.01 % Pb, 2.71% ± 0.08 Al, 0.22% ± 0.01 Fe, etc.. Copper leaching was increased for sulfuric acid concentrations up to 1.2 mol/L and hydrogen peroxide concentrations of 10.0 vol% for a pulp density of 100 g/L at 50°C over 4 h, whereas for the same concentrations of sulfuric acid and hydrogen peroxide copper leaching was decreased from 75.7 to 56.7% with an increase in pulp density from 25 to 125 g/L. Under the same optimum conditions and a 100 g/L pulp density, the leached copper concentration was 16.66 g/L (75.7%) and the concentrations of Pb, Al, Fe, and Ca were 0.1 g/L, 0.64 g/L, 0.13 g/L, 0.79g/L, respectively. Above 50°C and 500 rpm, the amount of leached copper decreased. With nitric acid, 98.3% copper leaching was obtained under the optimum conditions of 3 mol/L nitric acid and an agitation speed of 800 rpm at 60°C for 5 h at 25 g/L pulp density. Under optimum conditions and 100 g/L pulp density, the concentration of Cu in the leachate was 21.12 g/L (96%), and the concentrations of Pb, Al, Fe and Ca were 0.52 g/L, 0.91 g/L, 0.13 g/L, 1.70 g/L, respectively. At the same pulp density, nitric acid enabled better leaching of copper and other metals than sulfuric acid with 10.0 vol% hydrogen peroxide. The solid precipitates obtained in the leach liquors of PCBs included stannic oxide and calcium aluminum oxide in nitric acid and gypsum in sulfuric acid.
|dc.title||Leaching of metals from waste printed circuit boards (WPCBs) using sulfuric and nitric acids|
|dcterms.source.title||Environmental Engineering and Management Journal|
|curtin.department||Dept of Mining Eng & Metallurgical Eng|
|curtin.accessStatus||Fulltext not available|
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