Effect of the H3O+ concentration in the metal recovery process: Au, Cu, Ni and Zn contained in electronic scrap
Abstract
In the present work, leaching of non-noble metals was carried out in the O2-H2SO4 system at different concentrations of [H3O+], such as: 1x10-0.3 M, 1x10-1 M, 1x10-2 M, 1x10-2.5 M, 1x10-3 M, 1x10-4 M. It was noted that the rate of speed constants increased with increasing of acid concentrations, thus favoring the leaching rate of Cu, Ni and Zn; the reaction order for each metal a was: Cu, n = 0.65037, Ni, n = 0.1368 and Zn, n = 0.0895. In all cases, at the end of the leaching process, a golden solid powder was obtained; when this powder was characterized by scanning electron microscopy using energy dispersed X-ray spectroscopy, SEM-EDS, it was determined to be metallic gold with a purity level of 99.6%.
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References
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