Kumar, Manoj and Yoo, Kyoungkeun and Kim, Min-seuk and Jeong, Jinki and Lee, Jae-chun (2011) Leaching of metals from waste printed circuit boards(PCBS) by sulphuric acid in the presence of hydrogen peroxide and nitric acid. The Banaras Metallurgist, 16 . pp. 141-148.
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The aim of this paper is to understand the leaching behavior of copper from the waste printed circuit boards (PCBS) containing 22.01 % Cu, 6.7% Ca, 0.68% Sn, 0.59% Pb, 2.705% Al, 0.215% Fe, 0.09'% Ni, 0.063'% Mn, 0.021%Zn. 0.013% Ag, 0.005% Au etc. by sulfuric acid in the presence of hydrogen peroxide and nitric acid. The different pro-cess parameters viz. Temperature, concentration of sulf-uric acid and hydrogen peroxide, agitation speed solid liquid ratio were studied for leaching copper along with minor metals associated with PCB. The leaching of copper was found to increase with increase in sulfuric acid concentrcation up to 1.2 M sulfuric acid and 10.0 vol, % hydrogen peroxide and decrease in leaching of copper was observed from 75.80 to 56.68% with increase in pulp density from 25 to 125 g/L. The studies showed the optimum dissolution of 75.70% Cu under the experimental condition of 323 K, 1.2 M sulfuric acid 10.0 vol. % hydrogen pero-xide, 500 rpm, 100 g/L pulp density in 4 h. The other metals leached with copper were 0 10 g/L Pb, 0 16 g/L Al, 0.13 g/L Fe, 0.79 g/L Ca, etc. With nitric acid, almost total dissolution 98.3% was obtained under, the optimum condition of 3 M nitric acid, 800 rpm, 333 K in 5 h at solid/liquid ratioto 100 g/L, the leaching of copper decreased marginally to 95.95% and leach solution: contained 21.12 g/L Cu along with other minor constituents as 0.52 g/L Pb, 0.91 g/L Al, 0.13 g/L Fe, 1. 70 g/L Ca etc. A solid lirecipitate has been obtained in the leach liquor of PCBs as stannic oxide and calcium aluminum oxide in nitric acid and gypsum in sulfuric acid medium.
|Uncontrolled Keywords:||Sulphuric acid, Hydrogen peroxide, Copper|
|Divisions:||Metal Extraction and Forming|
|Deposited By:||Sahu A K|
|Deposited On:||10 Aug 2011 16:57|
|Last Modified:||21 Nov 2011 12:36|
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