Tecnologia em Metalurgia, Materiais e Mineração (Jun 2015)

RECYCLING OF PRINTED CIRCUIT BOARDS AIMING SILVER RECOVERY: A HYDROMETALLURGICAL ROUTE STUDY

  • Marcos Paulo Kohler Caldas,
  • Viviane Tavares de Morae,
  • Eduardo Junca ,
  • Jorge Alberto Soares Tenório,
  • Denise Crocce Romano Espinosa

DOI
https://doi.org/10.4322/2176-1523.0850
Journal volume & issue
Vol. 12, no. 2
pp. 102 – 108

Abstract

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The aim of this paper is characterize printed circuit board of computers and propose a hydrometallurgical route for silver recovery present in its composition. Initially, the printed circuit board was comminuted in both knife and hammer mills. The comminuted material was characterized by sieve analysis, chemical analysis by inductively coupled plasma optical emission spectrometry (ICP-OES) and loss on ignition. Leaching tests were conducted in sulfuric acid, sulfuric acid in an oxidizing medium and nitric acid. The results indicated that the printed circuit board is mainly composed of copper (19.42%). Silver content of 0.045% was found. The route for silver recovery was leaching in sulfuric acid at 75°C for 18 hours. Then, leaching in sulfuric acid at 75°C in an oxidizing medium for 6 hours and nitric acid leaching at room temperature for 2 hours. Through of this route, 96.6% of silver was recovered.

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